Battery pack and electrical equipment using the battery pack

Abstract

To provide a battery pack capable of switching output of a high voltage and a low voltage.SOLUTION: A battery pack stores three cell units 156-158 including a plurality of cells therein and comprises a voltage switching mechanism 170 for switching an output voltage. The voltage switching mechanism 170 includes a rotary terminal base 171 which is pivoted on a substrate 160 by a rocking shaft 172. When the battery pack is mounted in an electrically-driven tool body, a switching projection 24A at a main body side pushes one side of the rotary terminal base 171 at a position of an arrow 25, such that the rotary terminal base 171 is rotated and moved to a second position shown in Fig. 9(1) and parallel voltages (36 V) of the cell units 156-158 are outputted from output terminals (161 and 162) of the battery pack. When the battery pack is removed from the electric apparatus main body, the voltage switching element stays at the second position and a connection state is maintained in a second state.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to an electric device having a load such as a motor and lighting, and a power supply device such as a battery pack that supplies power to such an electric device.

Background Art

[0002] Electric devices such as power tools are being driven by battery packs using secondary batteries such as lithium ion batteries, and the cordless trend of electric devices is progressing. For example, in a handheld power tool that drives a tip tool with a motor, a battery pack containing a plurality of secondary battery cells is used, and the motor is driven by the electrical energy stored in the battery pack. The battery pack is configured to be detachable from the power tool main body. When the voltage drops due to discharge, the battery pack is removed from the power tool main body and charged using an external charging device.

[0003] In cordless power tools and electric devices, ensuring a predetermined operating time and a predetermined output are required. Along with the improvement in the performance of secondary batteries, higher output and higher voltage have been achieved. In addition, as electric devices powered by battery packs are developed, battery packs with various voltages have been commercialized. Usually, the output voltage of a battery pack is fixed. However, in Patent Document 1, a plurality of battery units are provided in a housing that houses the battery, and a power supply device for an electric device is proposed that can select whether to output them in series connection or parallel connection by connection means, thereby enabling compatibility with devices of different voltages.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For a user, when using a plurality of power tools and electrical appliances, it is cumbersome to prepare a plurality of types of battery packs, and it is desired to realize a user-friendly battery pack that can handle power tools and electrical appliances with different voltages by switching the voltage. Moreover, it has been desired to realize a voltage switching type with a battery pack that can be easily attached to an electrical appliance, rather than a power supply device of a separate body type such as that of Patent Document 1. In addition, according to regulations regarding transportation, in a battery pack using a plurality of lithium ion batteries or the like, when the total power capacity of the lithium ion batteries or the like connected to each other exceeds a predetermined value, special measures need to be taken during transportation. Therefore, when transporting an electrical appliance, it is desirable to realize a battery pack capable of interrupting the mutual connection of a plurality of lithium ion batteries or the like housed in the battery pack, and an electrical appliance using the same.

[0006] The present invention has been made in view of the above background, and an object of the present invention is to provide a battery pack capable of switching the output voltage and an electrical appliance using the same. Another object of the present invention is to provide a battery pack that can be shared among electrical appliances with different voltages and an electrical appliance using the same. Another object of the present invention is to provide a battery pack that can easily perform voltage setting according to a corresponding electrical appliance and effectively prevent voltage setting errors, and an electrical appliance using the same. Another object of the present invention is to provide a battery pack capable of interrupting the mutual connection of a plurality of cell units housed in the battery pack and an electrical appliance using the same.

Means for Solving the Problems

[0007] An overall invention among the inventions disclosed in the present application will be described as follows.

[0008] According to one feature of the present invention, A battery pack having a housing that houses a plurality of cell units each having at least one cell, the housing having a lower surface, an upper surface formed higher than the lower surface at the rear thereof, a stepped portion formed between the lower surface and the upper surface, a plurality of slots extending rearward from the stepped portion so that terminals of an electric device body can be inserted into the upper surface, and a pair of rails spaced apart in the left-right direction and extending in the front-rear direction, and is configured to be mounted by moving forward with respect to the electric device body along the pair of rails. The battery pack has a positive terminal connected to the positive electrode of a first cell unit constituting the plurality of cell units, and a negative terminal connected to the negative electrode of a second cell unit constituting the plurality of cell units and arranged to be spaced apart from the positive terminal in the left-right direction, a plurality of power terminals directly connected to the terminals of the electric device body, and a switching terminal provided separately from the positive terminal and the negative terminal and configured to switch the connection state of the plurality of cell units when directly connected to the terminals of the electric device body. When the battery pack is moved forward with respect to the electric device body along the pair of rails and mounted on the electric device body, the positive terminal, the negative terminal, and the switching terminal are arranged in a plurality of slots extending rearward from the stepped portion so as to be able to fit with the terminals of the electric device body.

[0009] According to another feature of the present invention, The positive terminal, the negative terminal, and the switching terminal are arranged within the region of the stepped portion in the vertical direction and within a plurality of slots in the front-rear direction. Further, the switching terminal of the battery pack has a first switching terminal connected to the positive electrode of cell units other than the first cell unit among the plurality of cell units, and a second switching terminal connected to the negative electrode of cell units other than the second cell unit among the plurality of cell units. The first switching terminal and the positive terminal are located inside a first slot among the plurality of slots, being close to and spaced apart from each other in the vertical direction. The second switching terminal and the negative terminal are located inside a second slot among the plurality of slots, being close to and spaced apart from each other in the vertical direction. Furthermore, in the vertical direction, a first partition wall made of resin is provided between the first switching terminal and the positive terminal of the battery pack, and a second partition wall made of resin is provided between the second switching terminal and the negative terminal.

[0010] According to still other features of the present invention, The positive terminal, the negative terminal, and the switching terminal are arranged within a region of a step portion in the vertical direction of the battery pack and within a plurality of slots in the front-rear direction. Further, the switching terminal has a first switching terminal connected to the positive electrode of cell units other than the first cell unit among the plurality of cell units, and a second switching terminal connected to the negative electrode of cell units other than the second cell unit among the plurality of cell units. The first switching terminal and the positive terminal are located inside the first slot among the plurality of slots, being close to and separated from each other in the vertical direction. Also, the second switching terminal and the negative terminal are located inside the second slot among the plurality of slots, being close to and separated from each other in the vertical direction.

[0011] According to still other features of the present invention, The high-voltage electrical equipment main body capable of mounting the battery pack includes a pair of rail grooves that fit with a pair of rails of the battery pack, a positive input terminal and a negative input terminal that directly fit with the positive terminal and the negative terminal of the battery pack respectively, a switching element configured to directly fit with the switching terminal of the battery pack and switch the connection state of the plurality of cell units to a series connection state, and a terminal portion where the positive input terminal, the negative input terminal, and the switching element are arranged. When the battery pack is moved forward relative to the electrical equipment main body along the pair of rail grooves and mounted on the electrical equipment main body, the positive input terminal, the negative input terminal, and the switching element are arranged so as to be able to fit with the positive terminal, the negative terminal, and the switching terminal of the battery pack respectively within the plurality of slots extending rearward from the step portion. Also, the low-voltage electrical equipment main body to which the battery pack can be connected has a switching element configured to directly fit with the switching terminal of the battery pack and switch the connection state of the plurality of cell units to a parallel connection state. When the battery pack is connected, the switching terminal and the switching element directly fit with each other, and the first cell unit and the second cell unit are connected in parallel. When the battery pack is removed, the fitting between the switching terminal and the switching element is released, and the parallel connection between the first cell unit and the second cell unit is released.

Advantages of the Invention

[0012] According to the present invention, since it is possible to switch between connecting a plurality of cell units housed in a battery pack in parallel with each other or in series, the output voltage can be switched, and a battery pack that can be shared between electrical devices of different voltages and an electrical device using the same can be provided.

[0013] Also according to the present invention, when the battery pack is connected to the main body of the electrical device, the output voltage of the battery pack automatically switches to an output voltage suitable for the main body of the electrical device to which it is connected. Therefore, it is possible to easily perform voltage setting according to the corresponding electrical device, and a battery pack that can effectively prevent voltage setting errors and an electrical device using the same can be provided. Also according to the present invention, it is possible to provide a battery pack that suppresses an increase in the size and weight of the battery pack.

[0014] Also according to the present invention, since a voltage switching element for switching the output voltage of the battery pack is arranged in a terminal arrangement area where the power terminals of the battery pack are arranged, it is possible to provide an electrical device in which both or one of the main body of the electrical device and the battery pack are configured compactly.

Brief Description of the Drawings

[0015]

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Mode for Carrying Out the Invention

Example

[0016] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the following figures, the same parts are denoted by the same reference numerals, and repeated explanations are omitted. Also, in this specification, the front, rear, left, right, up, and down directions of the power tool main body, the mounting direction of the battery pack, and the front, rear, left, right, up, and down directions of the battery pack viewed alone are described as the directions shown in the figures. Furthermore, for the convenience of explanation, the mounting direction of the battery pack is described based on the situation where the battery pack is moved without moving the power tool main body or the electrical equipment main body.

[0017] FIG. 1 is a diagram for explaining the mounting state of the battery pack according to the present embodiment on the power tool. A power tool, which is a form of an electric device, has a battery pack and is a tool for fastening bolts, nuts, screws, etc. with a tip tool such as a bit, and is so-called an impact tool. The power tool main body 30 is a tool for performing a tightening operation on bolts, nuts, etc. (not shown) by applying a rotational force and an axial impact force to a tip tool such as a socket wrench (not shown). These power tool main bodies 1, 30 include housings 2, 32 which are outer frames forming the outer shape, and handle portions 3, 33 are formed on the housings 2, 32. An operator holds the power tool main bodies 1, 30 with one hand or while gripping with one hand and supporting with the other hand to perform work. The power tool main bodies 1, 30 drive a motor (not shown) housed inside the housings 2, 32 using direct current supplied from the battery pack 15 or 100 as a power source. Trigger-like operation switches 4, 34 are provided near a part of the handle portions 3, 33 where the index finger touches when the operator grips, and battery pack mounting portions 10, 40 for mounting the battery packs 15, 100 are formed below the handle portions 3, 33.

[0018] The electric tool main body 1 is an electrical device that uses a battery pack 15 with a rated voltage of 36V. Therefore, like the combination of arrow a, the battery pack 15 can be mounted on the battery pack mounting portion 10 of the 36V-compatible electrical device (electric tool main body 1). On the other hand, the electric tool main body 30 requires a high voltage equivalent to the commercial voltage of 108V, and a battery pack 100 capable of outputting 108V is mounted on the battery pack mounting portion 40 as shown by arrow b1. Inside the battery pack 100 capable of outputting a high voltage, 30 cells of lithium-ion batteries with a rated voltage of 3.6V are accommodated. As described above, in the electric tool main bodies 1 and 30, it is normal to mount dedicated battery packs 15 and 100 corresponding to the rated voltage. However, in this embodiment, the battery pack 100 is configured to support multiple voltages and enable output at a low voltage, so that the battery pack 100 can also be mounted on the 36V-compatible electric tool main body 1 as shown by arrow b2. In order to enable the battery pack 100 to be mounted on the electric tool main bodies 1 and 30 with different voltages as shown by arrows b1 and b2, it is important to make the shapes of the battery pack mounting portions 10 and 40 substantially the same and to make the voltage of the battery pack 100 switchable. Also, when the set voltage of the battery pack 100 does not correspond to the voltage of the mounted electrical device or electric tool, it is important to configure it so that the battery pack 100 cannot be mounted.

[0019] FIG. 2 is a perspective view showing the shape of the battery pack mounting portion 10 of the power tool main body 1. Not limited to power tools only, in all electrical devices using a battery pack, a battery pack mounting portion 10 adapted to the mounted battery pack is formed so that an incompatible battery pack cannot be mounted. In the battery pack mounting portion 10, rail grooves 11a and 11b extending in parallel in the front-rear direction are formed in the inner wall portions on both the left and right sides, and a terminal portion 20 is provided therebetween. The terminal portion 20 is manufactured by integrally molding a non-conductive material such as synthetic resin, and three metal terminals, namely a positive input terminal 21, a negative input terminal 22, and an LD terminal 23 (abnormal signal terminal), are cast therein and firmly fixed. The LD terminal 23 (abnormal signal terminal) functions as a signal terminal for inputting or outputting information or a signal. The terminal portion 20 has not only a vertical surface 20a that serves as a butting surface in the mounting direction (front-rear direction), but also a horizontal surface (upper surface as viewed from terminals 21 to 23) 20b. The horizontal surface 20b becomes a surface that slides on the upper step surface 115 (described later in FIG. 3) when the battery pack 100 is mounted. A curved portion 12 that contacts the raised portion 132 of the battery pack 100 is formed on the front side of the horizontal surface 20b, and a protrusion 24 is formed near the center of the left and right of the curved portion 12. The protrusion 24 is a boss for screwing the housing of the power tool main body 1 that is formed in two parts in the left-right direction, and is fixed by a screw 26 and a nut from the left and right directions. The protrusion 24 also serves as a stopper for restricting the relative movement of the battery pack 100 in the mounting direction. The width S1 of the protrusion 24 in the left-right direction is set to a width corresponding to a stopper portion (described later) formed on the battery pack 100 side.

[0020] FIG. 3 is a view showing another power tool body 30A compatible with 108V. (1) is a side view in a state of being powered from a power cord 90, (2) is a bottom view of a battery pack mounting portion 40, and (3) is a view showing the shapes of the power cord 90 and a connector portion 93. The power tool body 30A has a brushless motor with specifications equivalent to alternating current 100V, for example, a brushless DC motor driven by an inverter circuit (described later in FIG. 4). Therefore, direct current 108V output from the battery pack 100 is input to the inverter circuit, or a commercial power source such as alternating current 100V (60 Hz) is rectified by a rectifier circuit described later and then input to the inverter circuit. By thus increasing the output voltage of the battery pack 100 to approximately the same level as the commercial voltage, it is possible to realize a high-output power tool body 30A that operates with either the battery pack or the commercial voltage, which is compatible with AC / DC. The power cord 90 attached to the power tool body 30A holds two terminals 92a and 92b on one side of a connection cord 94 and has a plug portion 91 for attachment to a commercial power outlet, and a connector portion 93 connected to the power tool body 30A is formed on the other side. In this embodiment, the location where the connector portion 93 is connected is arranged inside the battery pack mounting portion 40 after the battery pack 100 is removed. That is, when connecting the power cord 90 to the power tool body 30A, it is necessary to remove the battery pack 100 from the power tool body 30A. Conversely, when attaching the battery pack 100 to the power tool body 30A, it is necessary to remove the power cord 90.

[0021] FIG. 3(2) is a view of the battery pack mounting portion 40 of the power tool main body 30A as seen from below, and is a view taken in the direction of the arrow from the direction A in (1). This figure shows a state in which both the battery pack 100 and the power cord 90 have been removed. The battery pack 100 is mounted on the battery pack mounting portion 40 so as to be slid from the rear side to the front side (from the right to the left in the figure). Therefore, an opening portion is formed on the mounting surface 40a on the upstream side in the mounting direction, and two rail grooves 48a and 48b are formed on the side. Further, a recessed portion 40b is formed on the upstream side (rear side portion) of the opening portion so as to be recessed upward. Near the approximate center of the portion sandwiched between the rail grooves 48a and 48b of the mounting surface 40a, a terminal portion 41 connected to the positive terminal and the negative terminal of the battery pack 100 is provided. In this embodiment, an AC socket 49 is provided at a portion slightly rearward of the terminal portion 41. Pinnate first terminals 49a, second terminals 49b, and third terminals 49c are formed in the circumferential direction in the AC socket 49.

[0022] FIG. 3(3) is a diagram showing the shape of the connector portion 93 of the power cord 90. The left side is a view of the connector portion 93 seen from the outside in the longitudinal direction, and the right side is a side view showing the overall shape of the power cord 90 including the connector portion 93. A male thread is formed on the outer peripheral surface of the connector body 93a, and a cylindrical fixing screw 93b is rotatable relative to the outer peripheral side of the male thread and is held in a state where the axial movement amount is restricted. The outer shape of the connector portion 93 is circular, and at the inner peripheral portion, three female terminals, a first terminal 95a, a second terminal 95b, and a third terminal 95c, are arranged side by side in the circumferential direction. Here, for commercial power supply, only two of the first terminal 49a and the second terminal 49b need to be connected, and the third terminal 49c may be in a non-wired state inside the power tool body 30A or may be used as an earth wire. The fixing screw 93b holds the power cord 90 so as not to fall off from the power tool body 30A, and the female thread portion on the inner peripheral side of the fixing screw 93b is screwed with the male thread portion formed on the outer peripheral surface of the AC socket 49. In this way, after inserting the connector body 93a into the AC socket 49, by tightening the fixing screw 93b and screwing it with the male thread on the AC socket 49 side, the power cord 90 can be fixed so as not to fall off from the power tool body 30A.

[0023] Next, the configuration and operation of the drive control system of the motor 35 will be described with reference to FIG. 4. FIG. 4 is a block diagram showing the configuration of the drive control system of the motor 35. In the electric tool of this embodiment, the direct current supplied from the battery pack 100 is used to generate an exciting current by the inverter circuit 70, and the brushless motor 35 is rotated by flowing the exciting current through a predetermined coil of the motor 35 while switching the exciting current. The input from the battery pack 100 is input via a positive input terminal 81 connected to the positive terminal 161 of the battery pack 100 and a negative input terminal 82 connected to the negative terminal 162 of the battery pack 100. The motor 35 can be, for example, an inner rotor type, and includes a rotor 35a configured to include a plurality of sets (two sets in this embodiment) of permanent magnets (magnets) including N poles and S poles, a stator 35b composed of star-connected three-phase stator windings U, V, and W, and three rotation position detection elements (Hall elements) 65 arranged at predetermined intervals in the circumferential direction, for example, every 60°. These outputs are converted into a pulse train by the rotation position detection circuit 53 and output to the arithmetic unit 51. The rotation speed detection circuit 54 detects the rotation speed of the motor 35 using the output of the rotation position detection circuit 53 and outputs it to the arithmetic unit 51. In the arithmetic unit 51, the energization direction and time to the stator windings U, V, and W are determined using these outputs.

[0024] The control signal output circuit 52 forms a drive signal for switching predetermined switching elements Q1 to Q6 according to an instruction from the arithmetic unit 51 based on the output signals of the applied voltage setting circuit 58 and the rotation position detection circuit 53, and outputs the drive signal to the inverter circuit 70. The inverter circuit 70 includes six switching elements Q1 to Q6 such as IGBTs connected in a three-phase bridge configuration. Each gate of the switching elements Q1 to Q6 is connected to the control signal output circuit 52, and each emitter or each collector is connected to the stator windings U, V, and W connected in a star configuration. As a result, the six switching elements Q1 to Q6 perform a switching operation according to the switching element drive signal (drive signals such as H1 to H6) input from the control signal output circuit 52, and apply the DC voltage of the battery pack 100 applied to the inverter circuit 70 as three-phase (U-phase, V-phase, and W-phase) voltages Vu, Vv, and Vw to the stator windings U, V, and W.

[0025] The arithmetic unit 51 sets, via the switch operation detection circuit 57, whether or not the trigger 34A (or the operation switches 4 and 34 in FIG. 1) for operating the operation switch 56 is operated, changes the pulse width (duty ratio) of the PWM signal based on a signal from the applied voltage setting circuit 58 that changes according to the magnitude of the operation amount (stroke), and drives each gate of the six switching elements Q1 to Q6 via the control signal output circuit 52. By this drive control, the amount of power supplied to the motor 35 is adjusted, and the start / stop and rotational speed of the motor 35 are controlled. Here, the PWM signal is supplied to either the positive power supply side switching elements Q1 to Q3 or the negative power supply side switching elements Q4 to Q6 of the inverter circuit 70, and the amount of power supplied from the DC voltage of the battery pack 100 to each of the stator windings U, V, and W is controlled by rapidly switching the switching elements Q1 to Q3 or the switching elements Q4 to Q6.

[0026] Although not shown, the arithmetic unit 51 includes a microcomputer for outputting a drive signal based on a processing program and data. The arithmetic unit 51 includes a ROM for storing a processing program and control data, a RAM for temporarily storing data, a timer, and the like. The voltage across the capacitor 61 is detected by the voltage detection circuit 59 as the voltage of the input power supply and output to the arithmetic unit 51.

[0027] The power supply of the power tool main body 30A can be supplied not only by the battery pack 100 but also by using the power cord 90. The first terminal 49a and the second terminal 49b of the AC socket 49 for AC input provided in the power tool main body 30A are connected to the input side of the diode bridge 60. The diode bridge 60 is a rectifier circuit that performs full-wave rectification using four rectifying diodes so that current flows only in one direction, and converts an AC voltage into a DC voltage. The output of the diode bridge 60 is connected to the inverter circuit 70. Since the output of the diode bridge 60 is pulsating current, a smoothing circuit may be interposed between the diode bridge 60 and the inverter circuit 70. The magnitude of the current flowing through the inverter circuit 70 is measured by the current detection circuit 55 using the shunt resistor 62, and the set drive power is adjusted to be applied to the motor 35 by feeding back the value to the arithmetic unit 51.

[0028] FIG. 5 is a diagram for explaining the connection state of the power cord 90 to the power tool main body 30. (1) is an example of connection at the power tool main body 30, and (2) and (3) are diagrams showing examples of connection according to modified examples thereof. FIGS. (2) and (3) of the same figure are diagrams showing the power tool main bodies 30B and 30C according to modified examples of the present embodiment. In the form of the present embodiment shown in FIG. (1), since the AC socket 49 (see FIG. 3) is provided in the battery pack mounting portion 40, the power cord 90 cannot be attached when the battery pack 100 is mounted. Further, when attaching the power cord 90, it is necessary to always remove the battery pack 100. In this way, since the AC socket 49 for the power cord 90 is provided at a position that cannot be accessed when the battery pack 100 is mounted, it is possible to surely distinguish between the power supply from the battery pack 100 and the power supply from the power cord 90 without mistake. Further, since the power tool main body 30 is equipped with a brushless motor with a rated input voltage of 100 V or more, it is possible to drive it with a commercial AC power supply or with the battery pack 100, and an AC / DC shared power tool has been realized.

[0029] The power cord 90 may have a length sufficient for the operator to work while holding the handle portion 33 of the power tool main body 30A with one hand. However, in the case of temporary work in a place where the length of the power cord 90 does not reach, if the power cord 90 is removed and the battery pack 100 is mounted, the work can be performed equivalently without worrying about the output reduction of the power tool main body 30A. Further, the method of connecting the power cord 90 to the power tool main body 30A in the form shown in FIG. 5(1) has the advantage that the weight of the power tool main body 30A is reduced because the battery pack 100 must be removed during work with an AC power supply. Furthermore, when switching from operation using the power cord 90 to operation using the battery pack 100, since the battery pack 100 cannot be mounted unless the power cord 90 is removed, it is possible to surely prevent forgetting to remove the power cord 90. Further, when the battery pack 100 is mounted, the AC socket 49 is not exposed to the outside, so the risk of the AC socket 49 being exposed to dust, water, etc. can be significantly reduced, and the installation of a cover for covering the AC socket 49 can also be omitted.

[0030] FIG. 5(2) shows a power tool body 30B according to a modified example of the power tool body 30A in FIG. 5(1). Here, the position of the AC socket 49A is formed on the lower surface of the housing of the power tool body 30B, which is on the front side of the battery pack 100. With such an arrangement, it becomes possible to connect the power cord 90 while the battery pack 100 is mounted. In this embodiment, the output voltage of the battery pack 100 is 108V during DC connection, and the commercial AC power is 100V - 120V. Therefore, the power tool body 30B can be driven using either of the two inputs arbitrarily. However, when both power sources can be used, it is preferable to use the commercial AC power supplied from the power cord 90 because it can prevent the discharge of the battery pack 100. Therefore, in the power tool body 30B according to FIG. 5(2), input automatic switching means is provided to use the commercial AC power side when both the battery pack 100 and the commercial AC power can be used.

[0031] Fig. 6(1) is a circuit block diagram of the drive control system of the power tool main body 30B shown in Fig. 5(2). Basically, it is the same as the circuit shown in Fig. 4, but a semiconductor switching element 66 such as an IGBT (Insulated Gate Bipolar Transistor) is interposed in the middle of the positive input line from the battery pack 100. The gate signal of the switching element 66 is connected to the control signal line 66a from the arithmetic unit 51, and the arithmetic unit 51 controls the connection or disconnection between the source and drain terminals of the switching element 66. Also, a battery voltage detection circuit 67 for monitoring the voltage of the battery pack 100 and a commercial power supply detection circuit 68 for monitoring the presence (or voltage) of the AC voltage are provided, and the outputs of each are input to the arithmetic unit 51. When the commercial power supply 99 is available, the arithmetic unit 51 turns off the gate signal of the switching element 66 to cut off the input circuit from the battery pack 100. On the other hand, when the commercial power supply 99 becomes unavailable, the arithmetic unit 51 turns on the gate signal of the switching element 66 to connect the input circuit from the battery pack 100. With such a circuit configuration, in the power tool main body 30B, when the battery pack 100 is connected, DC 108V (rated) is supplied, and when it is connected to the AC outlet by the power cord 90 in that state, the AC power supply is automatically supplied. When the power cord 90 is removed, it automatically switches to driving by the battery pack 100, so a user-friendly power tool main body 30B has been realized. Also, since there is no need to worry about the attachment and detachment of the battery pack 100 and the connection state of the power cord 90, especially forgetting to remove the other when one is connected, the handling of attaching and detaching the battery pack 100 also becomes easy.

[0032] Returning to FIG. 5 again. FIG. 5(3) shows an electric tool main body 30C according to another modification of the present embodiment. The electric tool main body 30C is the same as FIGS. (1) and (2) in that it can be driven by both a DC 108V battery pack 100 and AC via a power cord 90, but the power cord 90 is connected via a connection adapter 75. Here, the connection adapter 75 is a so-called dummy case for connecting two output lines from the power cord 90 to a positive input terminal 81 and a negative input terminal 82 for the battery pack 100. No battery cells are housed inside the connection adapter 75. An AC socket having the same shape as the AC socket 49 shown in FIG. 3(2) is provided on the lower surface of the connection adapter 75. The first terminal 49a of the AC socket 49 is connected to the positive input terminal 81 by a power line 76a, and the second terminal 49b is connected to the negative input terminal 82 by a power line 76b. In this case, in the block diagram shown in FIG. 4, the input path of the battery pack 100 is changed so that it is also connected to the inverter circuit 70 via the diode bridge 60 when the battery pack 100 is in use. FIG. 6(2) shows the circuit.

[0033] Here, a positive terminal 161 and a negative terminal 162 of the connection adapter 75 are attached to the input terminals 81 and 82 of the diode bridge 60. Since the battery pack 100 is DC 108V, there is no problem even if it is connected via the diode bridge 60. Also, even if the positive terminal 161 and the negative terminal 162 of the connection adapter 75 are attached, the alternating current is rectified by the diode bridge 60, so the inverter circuit 70 can be operated in the same manner to drive the motor 35. In the present embodiment, a brushless DC motor is driven via a DC input of DC 108V and the inverter circuit 70, but the type of motor to be used is not limited to only brushless motors, and another motor driven at about AC 100 to 120V, for example, an AC commutator motor, may be used. With this configuration, it is also possible to drive an electric tool using an AC commutator motor with the battery pack 100, and an electric tool compatible with both AC and DC can be easily realized.

[0034] Next, the battery pack 100 capable of switching the output voltage between 36V and 108V will be described with reference to FIGS. 7 to 9. FIG. 7 is a perspective view showing the external shape of the battery pack 100. The housing of the battery pack 100 is divided in the vertical direction and is formed by a lower case 101 and an upper case 110 that are fixed by four screws (not shown). The upper case 110 is formed with a mounting portion in which two rails 138a and 138b are formed for mounting to the battery pack mounting portion 40. The rails 138a and 138b are in a direction parallel to the mounting direction of the battery pack 100 and are formed so as to be parallel to the left and right side surfaces of the upper case 110. The rails 138a and 138b are formed corresponding to the rail grooves 48a and 48b (see FIG. 3(2)) formed in the battery pack mounting portion 40 of the power tool main body 30. In a state where the rails 138a and 138b are fitted into the rail grooves 48a and 48b, the battery pack 100 is fixed to the power tool main body 30 by the operation of the latch mechanism. A flat lower step surface 111 is formed on the front side of the upper case 110, and an upper step surface 115 that is higher than the lower step surface 111 is formed near the center. The connecting portion between the lower step surface 111 and the upper step surface 115 becomes a stepped portion 112 formed in a stepped shape, and the front side region of the upper step surface 115 from the stepped portion 112 becomes a slot group arrangement region 120 (see FIG. 7(2)). A plurality of slots (121 to 124) extending rearward from the front stepped portion 112 are formed in the slot group arrangement region 120. Here, the positive terminal insertion port 121 is arranged on the side closer to the left rail 138b, and the negative terminal insertion port 122 is formed on the side closer to the right rail 138a. A low voltage switching member insertion port 123 and a high voltage switching member insertion port 124 are formed in a portion sandwiched between the positive terminal insertion port 121 and the negative terminal insertion port 122. Inside the positive terminal insertion port 121 and the negative terminal insertion port 122, metal positive and negative terminals that are not visible in the figure are arranged. Also, a voltage switching means described later is arranged in a portion (the internal space of the upper case 110) that overlaps the positions of the low voltage switching member insertion port 123 and the high voltage switching member insertion port 124. Note that in FIG. 7, only four slots (121 to 124) are shown in the slot group arrangement region 120, and slots other than the four are not shown, but slots for accommodating other connection terminals may be formed.Also, as described above, since terminals and voltage switching means (e.g., switching terminals) are arranged in the internal space of the upper case 110 where the slot group arrangement area 120 is located, the slot group arrangement area 120 becomes a terminal arrangement area.

[0035] On the rear side of the upper surface 115, a raised portion 132 is formed to protrude. The outer shape of the raised portion 132 protrudes above the upper surface 115, and a recessed stopper portion 131 is formed near the center thereof. The stopper portion 131 serves as a butting surface when the battery pack 100 is attached to the protrusion 24 (see FIG. 2) of the battery pack mounting portion 10. When the protrusion 24 on the side of the power tool main body 1 is inserted until it abuts against the stopper portion 131, a plurality of terminals 21 to 23 (see FIG. 2) arranged on the power tool main body 1 and a terminal group arranged on the battery pack 100 come into contact with each other to be in a conductive state. Inside the stopper portion 131, a slit 134 serving as a cooling air intake port communicating with the inside of the battery pack 100 is provided. Also, the locking portion of the latch 141 of the battery pack 100 pops out vertically outward at the lower portions of the rails 138a and 138b due to the action of a spring and engages with a recess (not shown) formed in the rail grooves 48a and 48b of the power tool main body 30, thereby preventing the battery pack 100 from falling off. In a state where the battery pack 100 is attached to the power tool main body 1, the slit 134 is covered so as not to be visible from the outside. The slit 134 is a air window used to forcibly flow cooling air into the battery pack 100 when the battery pack 100 is connected to a charger (not shown) for charging, and the cooling air intake port 134 is in a closed state when the battery pack 100 is attached to the power tool main body 30.

[0036] In FIG. 7(1), the terminal portion 20A on the side of the power tool main body 1 driven at 36V has a metal positive input terminal 21 and a negative input terminal 22 fixed by a synthetic resin terminal mounting portion. Here, a switching projection 24A for switching the output of the battery pack 100 to the low voltage side is further formed. The switching projection 24A is a switching element integrally formed with the base portion of the terminal portion 20A and is made of synthetic resin. The switching projection 24A itself is only for moving the rotary terminal base 171 (see FIG. 9) and is not used as a terminal for transmitting power or signals. Therefore, it is not necessary to make it of a conductive material and it may be integrally formed of the same insulating material as the base portion of the terminal portion.

[0037] FIG. 7(2) shows a state of being mounted on the terminal portion 80 on the side of the power tool main body 30 driven at 108V. The terminal portion 80 has a metal positive input terminal 81 and a negative input terminal 82 fixed by a synthetic resin base portion. Here, a switching projection 84 for switching the output of the battery pack 100 to the high voltage side is further formed. The switching projection 84 is a member integrally formed with the base portion of the terminal portion 80 and is made of synthetic resin. According to this embodiment, the external shape of the battery pack 100 is the same whether it is for 36V output or 108V output. The operator can simply mount it on the 36V electrical equipment main body or the 108V electrical equipment main body without worrying about the setting of the output voltage of the battery pack 100 at all, and the optimum output voltage is selected (switched) for the electrical equipment main body mounted by the switching projection 24A or the switching projection 84.

[0038] FIG. 8 is a perspective view showing the appearance of a cell pack 150 in which a plurality of cells 151 are stacked and combined into one pack, which is housed inside the battery pack 100. In the figure, (1) is a perspective view, and (2) is a side view seen from the axial direction of the cell 151. Here, a total of 30 cells 151 of a secondary battery that can be repeatedly charged and discharged, with a diameter of 14 mm and a length of 50 mm, called the 14500 size, are stacked. The cells 151 are grouped into units of 10 each, forming three cell units 156 to 158. Within each of the cell units 156 to 158, the axes A1 of the respective cells 151 are stacked in parallel, and the adjacent cells 151 are arranged so that their orientations are alternately reversed. The positive and negative terminals of the adjacent cells 151 are connected by a thin metal plate 159 to form ten series connections. The outermost cylindrical portion of the stacked cells 151 is covered by a separator 152 made of a synthetic resin that serves as an insulator, so that the cells 151 are held so as not to move relative to the separator 152. When a lithium-ion battery (rated output of 3.6 V per cell) is used as the cell 151, since an output of 36 V is obtained from each of the cell units 156 to 158, the + output (plus output, positive terminal) and the - output (minus output, negative terminal) of the cell units 156 to 158 are connected in parallel, and the output from the battery pack 100 can be taken out to be used as a high-capacity power source of 36 V. On the other hand, if the + output and the - output of the cell units 156 to 158 are connected in series, it can be used as a high-voltage power source of 108 V.

[0039] When 30 cells 151 of the 14500 size are stacked, the axial length is 50 mm, the width direction orthogonal to the axial direction is 124.8 mm, and the height direction orthogonal to the axial direction is 57.3 mm. Also, since the weight of a single cell 151 is about 23 g, the total weight of the cells 151 is 690 g. In terms of volume, the volume of the portion occupied by the cells 151 is 230,907 mm 3 and the volume occupied by the separator 152 is 67,392 mm 3 and the total volume is 298,299 mm 3As a result, it has become possible to keep the overall weight of the battery pack 100 below 800 g or 2 lb (pounds). Currently, the lithium-ion batteries widely used in the battery packs of power tools are those called 18650. The 18650 size means a diameter of 18 mm and a length of 65 mm, which slightly exceeds twice the volume of a cell of the 14500 size. In terms of weight, it is 46 g, which is twice the weight of a cell of the 14500 size. To obtain a DC of 108 V, if 30 cells of the 18650 size are stacked, just the weight of the cells will be 1380 g, and the weight of the battery pack itself will become heavy. Therefore, in a power tool that enables an operator to work while holding it with one hand, it will have a size and weight that are not practical.

[0040] According to the inventors' experiments, it was found that the upper limit for an operator to comfortably work with one hand is within 2 kg or 5 lb of the total weight of the power tool after the battery pack is installed. Therefore, when obtaining an output of 108 V using 30 cells of the 18650 size, it is difficult to realize a portable power tool that can be operated with one hand. In this embodiment, by stacking lithium-ion batteries of the 14500 size, which is the same size as a so-called AA dry battery, a high-voltage power tool could be realized while maintaining portability. In the battery pack 100 of this embodiment, an output voltage of 100 V or more equivalent to that of an AC power source could be surely ensured, and moreover, the cell weight of the cell pack 150 could be suppressed to 0.69 kg. Since a current of about 15 A can be obtained from this lithium-ion battery, the power-weight ratio as a battery pack could clear values of 100 V × 15 A / 0.69 kg = 2173 W / kg or more and 100 V / 0.69 kg = 144 V / kg or more.

[0041] FIG. 9(1) is a diagram showing a state when the battery pack 100 is attached to an electric tool main body or an electrical equipment main body with a rated voltage of 36V. The battery pack 100 includes a voltage switching mechanism 170 for switching whether to connect the outputs of the cell units 156 to 158 in parallel or in series. The voltage switching mechanism 170, which is a voltage switching element for switching the output voltage of the battery pack 100, includes a rotary terminal base 171 pivotally supported by a swing shaft 172 fixed on a substrate 160, and is provided in a terminal arrangement area where connection terminals for power supply are arranged in the mounting direction of the battery pack 100. The rotary terminal base 171 is a member for short-circuiting or opening a plurality of contacts located on the inner peripheral side and contacts located on the outer peripheral side of the connection terminals 173a to 173d by installing the plurality of square bar-shaped connection terminals 173a to 173d on members extending in two directions from the swing shaft 172. The rotary terminal base 171 functions as an operation unit for operating a changeover switch for switching the output voltage of the battery pack 100. The rotary terminal base 171 is made of synthetic resin, and two connection terminals 173a to 173d made of metal are cast at intervals on one side and the other side of the swing shaft 172. On the side closer to the negative terminal 162, the connection terminals 173a and 173b are arranged so as to expose one surface facing the substrate 160, and on the side closer to the positive terminal 161, the connection terminals 173c and 173d are arranged so as to expose one surface facing the substrate 160.

[0042] The substrate 160 is used to fix the positive terminal 161 and the negative terminal 162, and to arrange a plurality of electrodes (contacts) 176a to 176j for establishing or changing an electrical connection path from these terminals to the cell units 156 to 158. A plurality of contacts 176a to 176j are provided in an area at the upper part of the substrate 160 that partially overlaps with the rotation area of the rotary terminal base 171. By the connection terminals 173a to 173d exposed on the lower surface of the rotary terminal base 171 coming into contact with any of these contacts 176a to 176j, the electrical connection path from the positive terminal 161 to the negative terminal 162 is changed. The plurality of contacts 176a to 176j and the connection terminals 173a to 173d function as a changeover switch operated by an operating part for switching the output voltage of the battery pack 100. In the electric tool main body 1 for 36V, a switching projection 24A is formed on the terminal part 20A. The switching projection 24A functions as a switching element or a connecting element that abuts against the operating part to switch the output voltage, and is inserted into a third slot 123 or 124 between a first slot 121 into which the positive input terminal is inserted and a second slot 122 into which the negative input terminal is inserted. When the battery pack 100 is attached to the electric tool main body, the switching projection 24A pushes the rotary terminal base 171 at the position of the arrow 25, so that the rotary terminal base 171 rotates counterclockwise in a top view and reaches the position shown in Fig. 9(1). In this state, it can be understood that the connection terminal 173a shorts the electrodes (contacts) 176d and 176b, and the connection terminal 173b shorts the electrodes (contacts) 176e and 176c. Similarly, it can be understood that the connection terminal 173c shorts the contacts 176i and 176g, and the connection terminal 173d shorts the contacts 176j and 176h.

[0043] Fig. 9(2) shows the connection status when the rotary terminal base 171 rotates counterclockwise in a top view by the switching projection 24A as shown in (1). The + side output of the cell unit 156 is directly connected to the positive terminal 161. The + side output of the cell unit 157 is connected to the contact point 176b, and the + side output of the cell unit 158 is connected to the contact point 176g. The - side output of the cell unit 156 is connected to the contact point 176e, the - side output of the cell unit 157 is connected to the contact point 176j, and the - side output of the cell unit 158 is directly connected to the negative terminal 162. In this state, the contact points 176d and 176b, 176e and 176c, 176i and 176g, 176j and 176h are in a connected state. As a result, the cell units 156 to 158 are in a parallel connection state, and a DC of rated 36V is output between the positive terminal 161 and the negative terminal 162.

[0044] FIG. 10(1) is a diagram showing the state when the battery pack 100 is attached to an electric tool body or an electrical equipment body with a rated voltage of 108V. In an electric tool with a rated voltage of 108V, a switching projection 84 is formed on the terminal portion 80, and no projection is formed at the position of the switching projection 24A of the terminal portion 20 of the 36V device. The switching projection 84 functions as a switching element or a connecting element that abuts against the operation portion to switch the output voltage, and is inserted into a third slot 124 between a first slot 121 into which the positive input terminal is inserted and a second slot 122 into which the negative input terminal is inserted. When the battery pack 100 is attached to the electric tool body or the electrical equipment body in this state, the positive input terminal 81 contacts the positive terminal 161, and the negative input terminal 82 contacts the negative terminal 162. At the same time, the switching projection 84 contacts one arm of the rotary terminal base 171 as indicated by an arrow 84a, thereby rotating the rotary terminal base 171 clockwise in a top view. Due to this rotation, the connection relationship between the connection terminals 173a to 173d of the rotary terminal base 171 and the contact points 176a to 176j is switched. FIG. (2) of the same figure shows the connection state after switching. Here, when the position of the rotary terminal base 171 is switched from FIG. 9(2) to FIG. 10(2), the contact points 176d and 176a, the contact points 176e and 176b, the contact points 176i and 176f, and the contact points 176j and 176g are in a connected state. As a result, the cell units 156 to 158 are in a series connection state, and a direct current of 108V rated voltage is output from the positive terminal 161 and the negative terminal 162. Incidentally, it is preferable to provide a click mechanism or a latch mechanism on the swing axis 172 of the rotary terminal base 171 as a swing member so that the swing member does not swing unless a rotation torque equal to or greater than a predetermined value is applied to the swing member by the switching projection 24A or the switching projection 84. Further, since the contact points 176a and 176f are electrodes that are not connected anywhere, by eliminating these and increasing the electrode intervals between the contact points 176b and 176c, and the contact points 176g and 176h, the risk of short circuit between adjacent electrodes during switching may be reduced.

[0045] According to this embodiment, even in a cordless power tool, a high voltage equivalent to that of a commercially powered power tool can be obtained from the battery pack 100, enabling the realization of a high-output portable power tool or electrical equipment. Also, even if the number of cells is increased to raise the voltage, 30 lithium cells of the 14500 size are used instead of the 18650 size cells, resulting in a high-output yet small and lightweight tool with a large power-to-weight ratio. Furthermore, the battery pack 100 of this embodiment is configured to be able to switch the output between 36V and 108V by arranging a voltage switching element (voltage switching mechanism 170) inside the battery pack 100 to switch the connection of cell units 156 - 158, enabling operation of widely used power tools and electrical equipment rated at 36V. In the battery pack 100 of this embodiment, since the voltage switching mechanism 170 that functions as a voltage switching element is arranged at approximately the same height as the positions where the positive terminal 161 and the negative terminal 162 that function as power terminals are arranged, the vertical size of the battery pack 100 can be made compact.

Embodiment

[0046] Next, a second embodiment of the present invention will be described with reference to FIGS. 11 - 14. In the second embodiment, similar to the first embodiment, a battery pack 200 is provided that can switch the output voltage between two levels: 36V on the low voltage side and 108V on the high voltage side. FIG. 11 is a perspective view showing the shape of the battery pack 200 and the terminal portion connected thereto, where (1) shows the state when connected to an electrical device rated at 36V, and (2) shows the state when connected to an electrical device rated at 108V. The external shape of the battery pack 200 is basically the same as that of the battery pack 100 of the first embodiment shown in FIGS. 1 - 8, except for a part (the shape in the vicinity of the slot group arrangement area).

[0047] The battery pack 200 houses 30 cells 151 each of 14500 size lithium-ion batteries in a housing formed by joining a lower case 201 and an upper case 210. If an increase in the size of the housing is allowed, cells of 18650 size or cells of other shapes and sizes may be used. An attachment mechanism for attachment to the electric tool body 1 or the electric tool body 30 side is formed on the upper case 210 of the battery pack 200, and its configuration and shape are almost the same as those of the battery pack 100 of the first embodiment shown in FIG. 7. On the upper case 210, a lower step surface 211 for guiding the terminal portion on the electric device side and an upper step surface 215 disposed above it are formed, and a plurality of terminal insertion openings (slots) are formed at a step portion 212 that is the boundary between the lower step surface 211 and the upper step surface 215. Rail portions 238a and 238b that fit into the groove rails on the electric device body side are formed at the left and right side edges of the upper step surface 215. Here, five terminal insertion openings are shown in the left-right direction, but the number of terminal insertion openings to be arranged is arbitrary and may be further increased. A raised portion 240 is formed above the upper step surface 215, and latch portions 241 are provided on both the left and right sides of the raised portion 240. The latch portion 241 is linked to a latch claw 241a.

[0048] Fig. 11(1) shows the case when it is connected to an electrical equipment main body or a power tool main body 1 rated at 36V. The terminal part 270 provided on the electrical equipment main body 1 side has a narrow width in the left-right direction. The battery pack 200 is moved so that the positive input terminal 271 and the negative input terminal 272 are inserted into the two terminal insertion openings 222 and 224 closer to the center. The positive input terminal 271 and the negative input terminal 272 are connected to the switching terminals of the battery pack 200 to be described later and function as a switching element or a connecting element for switching the output voltage of the battery pack 200 to a low voltage. Further, they also function as a connecting element for low voltage for connecting a plurality of cell units in parallel to each other. Fig. 11(2) shows the case when it is connected to an electrical equipment main body or a power tool main body 30 rated at 108V. The terminal part 280 of the power tool main body 30 has a wider width in the left-right direction than the terminal part 270, and the region therebetween becomes a terminal arrangement region. The terminal arrangement region has a positive input terminal 281 and a negative input terminal 282 arranged near both left and right ends, and a connecting element 283 is formed substantially at the center in the left-right direction. When the battery pack 200 is attached to the power tool main body 30, the positive input terminal 281 and the negative input terminal 282 are inserted into the terminal insertion openings 221 and 225, and the connecting element 283 is inserted into the terminal insertion opening 223.

[0049] FIG. 12 is a connection circuit diagram of the battery pack 200. Three cell units 156 to 158 are accommodated in the battery pack 200. The cell units 156 to 158 are formed as the cell pack 150 shown in FIG. 8 and are held by the separator 152. Ten cells 151 of 14500-sized lithium ion batteries are connected in series respectively. Note that in FIG. 12, ten cells are illustrated as one battery. In the terminal insertion openings (slots) 221 to 225 for inserting the input terminals on the terminal parts 270 and 280 sides, one to four connection terminals are arranged side by side in the insertion direction of the terminal parts 270 and 280. The connection terminal group arranged here serves as a voltage switching element for switching the parallel connection and the serial connection of the battery pack 200. The pair of the terminal insertion opening 222 and the terminal insertion opening 224 corresponds to the terminal part 270 for 36V, and a switching terminal group (terminal group 232 and terminal group 234) for outputting a low voltage is arranged there. The positive input terminal 271 is mounted so as to contact each of the terminal group 232, and the negative input terminal 272 is mounted so as to contact each of the terminal group 234.

[0050] The pair of the terminal insertion port 221 and the terminal insertion port 225 corresponds to the terminal section 280 for 108V, and a switching terminal group (terminals 231 and 235) for outputting a high voltage is arranged therein. The positive input terminal 281 is mounted so as to contact the terminal 231, and the negative input terminal 282 is mounted so as to contact the terminal 235. The terminal 231 functions as a positive terminal, and the terminal 235 functions as a negative terminal. A connection element 283 for switching the output voltage is further provided at the left and right center portions of the terminal section 280. The connection element 283 serving as a voltage switching element for switching between parallel connection and series connection is inserted into the terminal insertion port 223. The connection element 283 has a conductive portion 283a on the front end side (the side close to the battery pack 200 in the figure) and a conductive portion 283c on the rear end side, and an insulator 283b is disposed between these conductive portions 283a and 283c, whereby the conductive portion 283a and the conductive portion 283c are electrically non-conductive. The purpose of the conductive portions 283a and 283c is a short-circuiting element for short-circuiting between predetermined terminals in the terminal group 233, and it is not necessary to wire from the conductive portions 283a and 283c on the electric device main body side. Therefore, the connection element 283 may be manufactured by casting a metal plate forming the conductive portions 283a and 283c into a connection element base made of a non-conductive body formed integrally with the terminal section 280, or by attaching a metal plate to the outer peripheral surface of the connection element base made of a non-conductive body or by subjecting the outer peripheral surface to a conductive treatment such as metal plating. In this way, a short-circuiting element for connecting a plurality of cell units in series with each other is added to the terminal section 280. As will be described later, the conductive portion 283a of the connection element 283 is connected to the switching terminal of the battery pack 200 and functions as a switching element or a connection element for switching the output voltage of the battery pack 200 to a high voltage, and further functions as an integrated high-voltage connection element for connecting a plurality of cell units 156 and 157 in series with each other. Similarly, the conductive portion 283c of the connection element 283 is also connected to the switching terminal of the battery pack 200 and functions as a switching element or a connection element for switching the output voltage of the battery pack 200 to a high voltage, and further functions as an integrated high-voltage connection element for connecting a plurality of cell units 157 and 158 in series with each other.

[0051] FIG. 13 is a diagram showing the shapes of terminals 231 to 235, (1) is a top view, and (2) is a side view of terminal group 232 (a view seen from the arrow direction in the B direction of (1)). Terminal group 232 has terminals 232a, 232b, and 232c. These terminals 232a, 232b, and 232c are connected to the connection elements of the low-voltage electrical equipment main body 1 and function as switching terminals for switching the output voltage of the battery pack 200 to a low voltage, and also function as parallel terminals for connecting a plurality of cell units in parallel to each other. Terminal group 232 is configured as a parallel terminal group in which a plurality of parallel terminals are arranged adjacent to each other. Terminal group 234 has terminals 234a, 234b, and 234c. These terminals 234a, 234b, and 234c are connected to the connection elements of the low-voltage electrical equipment main body and function as switching terminals for switching the output voltage of the battery pack 200 to a low voltage, and also function as parallel terminals for connecting a plurality of cell units in parallel to each other. Terminal group 234 is configured as a parallel terminal group in which a plurality of parallel terminals are arranged adjacent to each other. Terminal group 233 has terminals 233a, 233b, 233c, and 233d. These terminals 233a, 233b, 233c, and 233d are connected to the connection elements of the high-voltage electrical equipment main body 30 and function as switching terminals for switching the output voltage of the battery pack 200 to a high voltage, and also function as series terminals for connecting a plurality of cell units 156 to 158 in series to each other. Terminal group 233 is configured as a series terminal group in which a plurality of series terminals are arranged adjacent to each other. Here, terminals 231, 235, and terminals 232a, 233a, 234a have the same shape as the conventionally widely used terminals, which is formed by bending a flat plate into a U shape and making the both side surfaces near the opening end convex inward so that the narrowest part due to the convex part contacts both surfaces of the plate-like terminal on the terminal part side. Terminals 231, 235, 232a, 233a, 234a have a shape with the rear side closed because the metal terminal on the terminal part side to be fitted does not penetrate to the rear side. On the other hand, for the other terminal groups, that is, terminals 232b, 232c, 233b to 233d, 234b, 234c, since they are fitted in a state where the metal terminal on the terminal part side in contact penetrates from the front to the rear, openings are formed not only on the front side but also on the rear side.The specific shape is shown in the side view of (2). The upper rear vicinity (arrow 236a) of the terminal 232a is closed, while the terminals 232b and 232c are shaped such that not only the front side but also the rear side (vicinity indicated by arrows 236b and 236c) is open. Therefore, when the terminal portion 270 as shown in the figure is inserted in the direction of arrow 265, the positive input terminal 271 comes into contact with the three terminals 232a to 232c simultaneously, and each of them becomes electrically conductive. This connection state is the same for the negative input terminal 272 and the three terminals 234a to 234c. In this way, at one terminal insertion port, a plurality of terminals are arranged in the same direction (parallel direction) as the mounting direction, and the connection state of the cell units 156 to 158 in the battery pack 200 can be set to either a parallel connection or a series state using the electrode plates of the terminal portion.

[0052] FIG. 14 is a diagram showing a state when the battery pack 200 is attached to the terminal portions 270 and 280, where (1) is a 36V output state and (2) is a 108V output state. The terminal portion 270 in the 36V output state shown in (1) has a positive input terminal 271 and a negative input terminal 272. The positive input terminal 271 is electrically connected to the terminals 232a, 232b, and 232c when they are in contact. The terminal 232a is connected to the + terminal (positive electrode) of the cell unit 156, the terminal 232b is connected to the + terminal of the cell unit 157, and the terminal 232c is connected to the + terminal of the cell unit 158. Therefore, the positive input terminal 271 is connected to the + terminals of the three cell units 156 to 158. Similarly, the negative input terminal 272 is electrically connected to the terminals 234a, 234b, and 234c when they are in contact. The terminal 234a is connected to the - terminal (negative electrode) of the cell unit 156, the terminal 234b is connected to the - terminal of the cell unit 157, and the terminal 234c is connected to the - terminal of the cell unit 158. Therefore, the negative input terminal 272 is connected to the - terminals of the three cell units 156 to 158. Since nothing is connected to the terminal group 233, the terminals 233a to 233d are in an open state. As a result, the cell units 156 to 158 are connected in parallel, that is, a DC of rated 36V is output to the positive input terminal 271 and the negative input terminal 272.

[0053] FIG. 14(2) is a diagram showing the state when the battery pack 200 is attached to the terminal portion 280. The terminal portion 280 at the time of 108V output has a positive input terminal 281, a negative input terminal 282, and a connection element 283. The positive input terminal 281 only contacts the terminal 231 connected to the + terminal of the cell unit 156. Similarly, the negative input terminal 282 only contacts the terminal 235 connected to the - terminal of the cell unit 158. Further, the connection element 283 (connection terminal) is inserted so as to contact four terminal groups (series terminal elements 233a to 233d). By this connection element 283, the terminal 233a and the terminal 233b are short-circuited by the conduction portion 283a (see FIG. 12), and the terminal 233c and the terminal 233d are short-circuited by the conduction portion 283c (see FIG. 12). Here, between the terminal 233b and the terminal 233c, a non-conductive state is maintained by an insulator 283b (see FIG. 12) formed on the connection element 283. Since the terminal 233a is connected to the - terminal of the cell unit 156 and the terminal 233b is connected to the + terminal of the cell unit 157, a series connection state between the cell units 156 and 157 is established. Similarly, since the terminal 233c is connected to the - terminal of the cell unit 157 and the terminal 233d is connected to the + terminal of the cell unit 158, a series connection state between the cell units 157 and 158 is established. As a result of these conduction states, the cell units 156 to 158 are connected in series, and a DC of rated 108V is output to the positive terminal 231 and the negative terminal 235. Note that each terminal of the terminal group 232 and the terminal group 234 is left open.

[0054] As described above, in the second embodiment, a terminal group for switching the voltage is provided, and the switching terminal group is configured by adjacently arranging terminals extending from each of a plurality of different cell units. Therefore, the battery pack 200 that can support a plurality of power sources can be realized. In particular, since the series terminal group (series terminal elements 233a to 233d) for connecting a plurality of cell units in series, which is connected to the positive or negative electrode of a plurality of cell units, is provided in the slot 223, the battery pack 200 capable of switching between 36V and 108V can be realized. At this time, by setting the terminal portions 270 or 280 on the side of the electric device main body such as the electric tool main body to the shape shown in the figure, the slot (221 or 222) into which the positive input terminal is inserted and the negative input terminal are inserted. Since a third slot (223) into which a switching element (connection element 283) for switching the output voltage is inserted is provided separately from the slots (224 and 225), the output voltage from the battery pack 200 side is automatically switched only by mounting the battery pack 200. Therefore, the operator does not need to pay attention to the operation of switching the battery voltage, and there is no risk of damaging the electric device main body side due to a setting voltage error. Further, when the battery pack 200 is removed, the three cell units 156 to 158 are in an open state (non-connected state), so that an optimal state can be achieved during storage and transportation. In the battery pack 200 of the second embodiment, the terminal group 232, the terminal group 234, and the connection element 283 that function as voltage switching elements, and the terminals 231, 235, the terminal group 232, and the terminal group 234 that function as power supply terminals are arranged at positions having substantially the same height in the vertical direction. Therefore, the vertical size of the battery pack 200 can be configured to be compact. Further, since the terminals 233a, 233b, 233c, 233d that function as series terminals, the terminal 231 that functions as a positive terminal, and the terminal 235 that functions as a negative terminal are arranged at positions having substantially the same height in the vertical direction, the vertical size of the battery pack 200 can be configured to be compact. Furthermore, since the terminals 233a, 233b that function as series terminals are configured as a series terminal group arranged adjacent to each other, and the conduction portion 283a functions as an integrated high-voltage connection element connected to this series terminal group, the electric device main body can have a simple structure.Similarly, terminals 233c and 233d that function as series terminals are configured as another series terminal group arranged adjacent to each other, and the conduction part 283c functions as an integrated high-voltage connection element connected to this series terminal group, so the main body of the electrical device can have a simple structure. And since a plurality of series terminal groups are arranged in a direction perpendicular to the left-right direction, and a plurality of integrated high-voltage connection elements are arranged in a direction perpendicular to the left-right direction, the left-right size of the battery pack and the main body of the electrical device can be made compact.

[0055] The structure of the battery pack 200 using the second embodiment is not limited to only the voltage-switching type battery pack, but can also be effectively applied to a battery pack with a fixed voltage. FIG. 15 shows the structure of such a battery pack. FIG. 15 is a diagram for explaining the circuit diagram of a battery pack 200A dedicated to 108V. Here, it has the same structure as that obtained by removing the terminal groups 232 and 234 in FIG. 14(2), and the terminal insertion openings 222 and 224 (both see FIG. 11) formed at the insertion positions of the terminal groups 232 and 234 are closed. The electric device main body for 108V uses a terminal part 280 having a positive input terminal 281, a negative input terminal 282, and a connection element 283. The structure of the terminal part 280 is the same as the structure shown in FIG. 12. The connection element 283 has a conduction part 283a on the front end side and a conduction part 283c on the rear end side, and the space between these conduction parts 283a and 283c is electrically connected in a non-conductive state by an insulator 283b. In this way, when the terminal part 280 is connected using a plurality of terminal groups, the series connection state of the cell units 156 to 158 is established. Therefore, when the battery pack 200A is not mounted on the electric device, the three cell units 156 to 158 are in a non-connected state, so that it can be in an optimal state during storage and transportation.

[0056] FIG. 15(2) is a circuit diagram showing a battery pack 200B of another modified example. (2) divides the connection element 283 in (1) into two in the left-right direction and splits it into a first connection terminal 285 and a second connection terminal 286. Along with this division, terminals 233a to 233d are arranged separately in the horizontal direction. The first connection terminal 285 is a metal plate for short-circuiting the terminal 233b connected to the + terminal side of the cell unit 157 and the terminal 233a connected to the - terminal side of the cell unit 156. Similarly, the second connection terminal 286 is a metal plate for short-circuiting the terminal 233c connected to the - terminal side of the cell unit 157 and the terminal 233d connected to the + terminal side of the cell unit 158. In this modified example, the same effect as in (1) can be obtained, and the installation spaces for terminals 233a and 233b, 223c and 233d can be made smaller, which is advantageous for mounting on an existing battery pack. In the modified example of FIG. 15(2), if six rows of terminal insertion openings are provided in the horizontal direction, terminal groups 232 and 234 (see FIG. 13) for 36V output can be arranged in the configuration of (2), and a battery pack with a shorter length of terminals in the front-rear direction can be realized.

Embodiment

[0057] Next, a third embodiment of the present invention will be described with reference to FIGS. 16 to 20. In the battery pack 300 of the third embodiment, it is common in that the output voltage of the battery pack can be switched between two levels, a low voltage side and a high voltage side, as compared with the first and second embodiments. However, in the third embodiment, the voltage ratio is switched not by three times as in 36V and 108V, but by two times as in 18V and 36V. FIG. 16 is a schematic perspective view showing the shape of the battery pack 300 according to the third embodiment of the present invention and the terminal portions 370 and 380 attached thereto. The electrical devices that can be attached to the battery pack 300 are of two types: a rated 18V device having a terminal portion 370 and a rated 36V device having a terminal portion 380. A positive input terminal 371 and a negative input terminal 372, which are a first power input terminal set (device-side power terminals), are formed in the terminal portion 370. A positive input terminal 381 and a negative input terminal 382, which are a second power input terminal set (device-side power terminals), are formed in the terminal portion 380. These terminal portions 370 and 380 are provided in the battery pack mounting portion on the electrical device main body side. The positive input terminals 371 and 381 and the negative input terminals 372 and 382 are formed of metal plate-like members, and the base portions for fixing them are formed of molded products of non-conductive materials such as synthetic resin. The positive input terminals 371 and 381 and the negative input terminals 372 and 382 each function as a switching element or a connecting element that abuts against the operation portion of the battery pack 300 to switch the output voltage of the battery pack 300.

[0058] The battery pack 300 illustrated here is a schematic view, and a plurality of slits 321 to 324 are formed from a stepped portion 312 between a lower surface 311 and an upper surface 315 to the rear side. The upper shape of the battery pack 300 including these slits 321 to 324 may be made substantially the same as the shape of the battery pack 100 shown in FIG. 7, but descriptions of raised portions, latch portions, etc. are omitted here. The terminal portion 370 for 18V is configured to be narrow in the left-right direction, and the terminal portion 380 for 36V is configured to be wide in the left-right direction. According to the difference in the widths of these terminal portions 370 and 380, the interval between the positive input terminal 371 and the negative input terminal 372 is formed to be narrow, and the interval between the positive input terminal 381 and the negative input terminal 382 is formed to be wide. The region occupied by the low-voltage terminal set (371, 372) is arranged to be included in the range occupied by the high-voltage terminal set (381, 382). The positive input terminal 371 and the negative input terminal 372 are respectively inserted into the slits 322 and 323, and the positive input terminal 381 and the negative input terminal 382 are respectively inserted into the slits 321 and 324. The positions of these terminals and slits are appropriately guided by a rail groove formed in the battery pack mounting portion on the electric tool body side and a rail portion (not shown here) formed in the battery pack 300. In this way, by providing two patterns of slits into which the clips (positive input terminals 371, 381 and negative input terminals 372, 382) of the terminal portion on the electric device body side are inserted, and attaching 18V and 36V products with different widths of the clips of the terminal portion, output switching is made possible. The operator can obtain an appropriate output voltage from the battery pack 300 simply by mounting the battery pack 300 on an electric device body such as an 18V electric tool or a 36V electric device body.

[0059] FIG. 17 is a diagram showing the components of a voltage switching mechanism (voltage switching element) 320 disposed inside the battery pack 300, particularly in the vicinity of the positions of slits 321 to 324 (see FIG. 16) on the rear side of the step portion 312 (terminal arrangement region). The voltage switching mechanism 320 is a switching means, and has two movable guide members 330 and 340 made of synthetic resin in which metal terminal members are cast. These are biased by a biasing means such as a spring 348 so as to move away from each other in a direction intersecting the mounting direction of the battery pack 300 to the electrical equipment main body. The movable guide members 330 and 340 function as operating portions that come into contact with a switching element of the electrical equipment main body and are operated to switch the output voltage of the battery pack 300. Four contact terminals (351 to 354) are provided near both the left and right sides and the rear side near the center of the movable guide members 330 and 340. Terminal mounting portions 331 and 341 for inserting the positive input terminal 371 and the negative input terminal 372 are formed on the movable guide members 330 and 340. The left diagram in FIG. 17(1) shows the positions of the movable guide members 330 and 340 when the battery pack 300 is not mounted on the electrical equipment main body. In this state, the positive input terminal 371 and the negative input terminal 372 can be directly inserted into the terminal mounting portions 331 and 341. On the other hand, the situation is different when mounting the terminal portion 380 as shown in the left diagram of FIG. 17(2). When the battery pack 300 is relatively moved with respect to the positive input terminal 381 and the negative input terminal 382 which are connection elements of the terminal portion 380, the positive input terminal 381 contacts the inclined portion 332 of the movable guide member 330, and the negative input terminal 382 contacts the inclined portion 342 of the movable guide member 340. This is because, due to the action of the spring 348, the parallel surfaces 333 and 343 of the movable guide members 330 and 340 are stationary at positions where the distance is wider than the distance between the positive input terminal 381 and the negative input terminal 382.

[0060] While the positive input terminal 381 is in contact with the inclined portion 332 and the negative input terminal 382 is in contact with the inclined portion 342, when the terminal portion 380 is pushed in like the arrow 349, that is, when the positive input terminal 381 and the negative input terminal 382 are inserted into the slits 321 and 324 (see FIG. 16) respectively, the movable guide members 330 and 340 move inward in the directions of the arrows 336 and 346 (the directions approaching each other) while compressing the spring 348. In the description of this embodiment, the meaning of the arrow 349 shown to bring the terminal portion 380 closer to the battery pack 300 only means that the distance from the battery pack 300 side is reduced, and it is only shown for convenience and does not indicate a fixed direction. It includes both the case of moving the battery pack 300 side toward the fixed electric device main body side and the case of moving the electric device main body side toward the battery pack 300 side. In this embodiment, for ease of understanding, these relative movements are described as the terminal portion 380 moving toward the battery pack 300 side like the arrow 349, but the state after mounting is the same regardless of which side is moved.

[0061] When the terminal portion 380 is further inserted while the movable guide members 330 and 340 move in the directions of the arrows 336 and 346, the spring 348 is further compressed and the movable guide members 330 and 340 approach each other more. Thus, the positive input terminal 381 enters between the parallel plane 333 on the outside (right side) of the movable guide member 330 and the first + terminal (first positive terminal) 351, and similarly, the negative input terminal 382 enters between the parallel plane 343 on the outside (left side) of the movable guide member 340 and the second - terminal (second negative terminal) 354. When it moves to a predetermined position in the direction of the arrow 349 in this inserted state, the mounting of the battery pack 300 is completed. By the movement of these movable guide members 330 and 340, the positions of the intermediate terminals 335 and 345 also move simultaneously, and the closest points of them change from the "non - contact" state to the "contact" state and become conductive. Further, the contact states between the movable guide members 330 and 340 and the terminals 351 - 354 change, and as a result, a DC of rated 36V is output to the terminal portion 380. The intermediate terminals 335 and 345 and the four contact terminals (351 - 354) function as a change - over switch operated by an operation unit to switch the output voltage of the battery pack 300.

[0062] FIG. 18 is a diagram for explaining a voltage switching mechanism 320 using movable guide members 330 and 340 and terminals 351 to 354. FIG. (1) of this figure is a diagram showing the accommodation position of the voltage switching mechanism 320 within the battery pack 300. In FIG. (1), the voltage switching mechanism 320 is located on the rear side of a stepped portion 312 formed by the lower surface 311 and the upper surface 315 of the battery pack, and is accommodated at a position overlapping the arrangement positions of a plurality of slits 321 to 324 (see FIG. 16) in a top view. The movable guide members 330 and 340 are movable members that move in the left-right direction on a terminal substrate 360 (see FIG. 18(3)), and the four contact terminals (351 to 354) are non-movable members fixed to the terminal substrate 360 and do not move.

[0063] FIG. 18(2) is an exploded view seen from the top surface of the voltage switching mechanism 320, and the components are shown spaced apart in terms of distance so that the configuration of each component can be understood. In FIG. (2), the movable guide member 330 has a basic shape in which a rectangular member and a triangular member are connected in a top view, and the basic shape portion is made of a synthetic resin such as plastic. A metal intermediate terminal 335 is cast into the synthetic resin portion, and these are firmly fixed. Two contacts 335c and 335d are formed on the rear side of the intermediate terminal 335, and a contact 335a that is bent convexly from the inside to the outside is formed so as to extend forward between the terminal mounting portions 331 and come into contact with the positive input terminal 371 of the terminal portion 370. A contact 335b that comes into contact with the contact 345b of the intermediate terminal 345 on the other movable guide member 340 side is formed in the inner portion (the left side of the movable guide member 330 in the figure). The movable guide member 340 and the intermediate terminal 345 cast therein are formed symmetrically with the movable guide member 330 and the intermediate terminal 335. Two contacts 345c and 345d are formed on the rear side of the intermediate terminal 345, and a contact 345a that is bent convexly from the inside to the outside is formed so as to extend forward between the terminal mounting portions 341 and come into contact with the negative input terminal 372 of the terminal portion 370. A contact 345b that comes into contact with the contact 335b of the other intermediate terminal 335 is formed in the inner portion (the right side of the movable guide member 340 in the figure). The contacts 335a and 345a are a low-voltage terminal set that outputs a low voltage and constitutes the first power supply terminal. A spring 348 (not shown in FIG. 18(2)) is cast between the movable guide members 330 and 340, and the movable guide members 330 and 340 are connected via an elastic body at the time of molding. The spring 348 is a metal compression coil spring.

[0064] On the rear side of the intermediate terminals 335 and 345, four terminals 351 to 354 are arranged. Arranged closer to the center in the left-right direction are the second + terminal (second positive terminal) 352 connected to the + terminal (positive terminal) of the first cell unit, and the first - terminal (first negative terminal) 353 connected to the - terminal (negative terminal) of the first cell unit. The second + terminal 352 is formed with contacts 352a and 352b that are bent convexly forward and arranged side by side in the left-right direction, and the first - terminal 353 is formed with contacts 353a and 353b that are bent convexly forward and arranged side by side in the left-right direction. The contact 335c selectively contacts either of the contacts 352a and 352b, and the contact 345c selectively contacts either of the contacts 353a and 353b.

[0065] On the right side of the intermediate terminal 335, the first + terminal (first positive terminal) 351 is arranged, and on the left side of the intermediate terminal 345, the second - terminal (second negative terminal) 354 is arranged. The first + terminal 351 is a member bent in a substantially L shape in top view, and at one end located on the front side, a contact 351a bent convexly from the outside to the inside is formed to contact the positive input terminal 381 (see FIG. 17) of the terminal portion 380, and at the other end located on the rear side, a contact 351b bent convexly forward is formed to contact the contact 335d of the intermediate terminal 335. The second - terminal 354 has a shape symmetric to the first + terminal 351 in the left-right direction. At one end located on the front side, a contact 354a bent convexly is formed to contact the negative input terminal 382 (see FIG. 17) of the terminal portion 380, and at the other end located on the rear side, a contact 354b bent convexly is formed to contact the contact 345d of the intermediate terminal 345. The contacts 351a and 354a are a high-voltage terminal set that outputs a high voltage and constitutes the second power terminal.

[0066] Figure 18(3) is a cross-sectional view of the C-C section of FIG. (1). The movable guide member 330 is covered on the upper side by the upper case 310 of the battery pack 300, and on the lower side is held by the terminal substrate 360 so as to be slidable in the left-right direction. On the upper surface of the terminal substrate 360, a guide rail 361 is formed that protrudes convexly upward and extends linearly in the left-right direction. Also, on the inner wall of the upper step surface 315 of the upper case 310, a guide rail 316 is formed that is provided so as to extend linearly in the left-right direction. On the other hand, on the upper surface of the movable guide member 330, a guide groove portion 334a is formed continuously in the left-right direction, and on the lower surface, a guide groove portion 334b is formed continuously in the left-right direction. Note that in the figures other than FIG. 18(3), the guide groove portion 334a of the movable guide member 330 and the guide groove portion 344a provided on the movable guide member 340 side are not shown.

[0067] In this way, by guiding the guide groove portion 334b by the guide rail 361 and guiding the guide groove portion 334a by the guide rail 316, the movable guide member 330 can move in a direction intersecting the mounting direction of the battery pack 300. Similarly, on the movable guide member 340 side, guide grooves and guide rails are formed, and by being guided by them, the movable guide member 340 can smoothly slide in a direction (left-right direction) intersecting the mounting direction of the battery pack 300 and will not move in the same direction (front-back direction) as the mounting direction. Since the intermediate terminal 335 is fixed to the movable guide member 330, it is arranged so as to be almost non-contact with the terminal substrate 360. For the second + terminal 352, the fixing pin portion 352c is fitted inside the terminal substrate 360, and the connecting pin penetrates the terminal substrate 360 and is soldered. Note that the pin portion 352c may be soldered without separating the pin portion 352c and the pin.

[0068] As described above, according to the third embodiment, in the terminal arrangement region on the upper surface of the terminal board 360 where the power supply terminals (positive terminal and negative terminal) are arranged, by the voltage switching elements (330, 340), which are a plurality of movable guide members movable in a direction intersecting the mounting direction of the battery pack 300, it is possible to switch between connecting a plurality of cell units in parallel and connecting them in series. Therefore, a battery pack 300 having an automatic voltage switching mechanism can be realized. In this embodiment, the moving direction of the movable guide member 330 is orthogonal to the mounting direction of the battery pack 300, but it is not necessarily limited to a crossing angle of 90 degrees, and it may be moved so as to cross obliquely by increasing or decreasing by a predetermined angle more than 90 degrees. Thus, in the third embodiment, since the movable guide members 330, 340 are arranged in the mounting direction of the battery pack 300 in the arrangement region of the terminals 351 to 354, 335, 345 (the region where the slits 321 to 324 are arranged), voltage switching can be performed without increasing the size of the battery pack.

[0069] Next, the connection state of the cell units by the voltage switching mechanism 320 when connected to the electric device main body with a rated voltage of 18V will be described with reference to FIG. 19. FIG. 19 shows (1) the state before the terminal portion 370 is mounted on the battery pack 300. FIG. (2) of the same figure shows the state after mounting, and shows the connection state from the four terminals 351 to 354 to the cell units 356, 357 as a circuit diagram. Two cell units 356, 357 are accommodated in the battery pack 300. The cell units 356, 357 are each an assembly in which five lithium ion battery cells 151 are connected in series, and their output is rated 18V. The + output (plus output) of the cell unit (first cell unit) 356 is wired to the first + terminal 351 by a lead wire, and the - output (minus output) is wired to the first - terminal 353 by a lead wire. Similarly, the + output of the cell unit (second cell unit) 357 is wired to the second + terminal 352 by a lead wire, and the - output is wired to the second - terminal 354 by a lead wire.

[0070] When the terminal unit 370 is not attached, the movable guide members 330 and 340 are biased by the spring 348 so as to move away from each other. In this state, the contact 335b and the contact 345b are separated and in a non-contact state. When the terminal unit 370 is attached starting from the state of FIG. 19(1), as shown in FIG. 19(2), the positive input terminal 371 of the terminal unit 370 is accommodated in the terminal attachment portion 331 through the slit 322 (see FIG. 17). As a result, the contact 335b and the positive input terminal 371 come into contact. Similarly, the negative input terminal 372 is accommodated in the terminal attachment portion 341 through the slit 323 (see FIG. 17). As a result, the contact 345b and the negative input terminal 372 come into contact. However, since the movable guide members 330 and 340 do not move in the direction of the arrow 349 nor in the direction orthogonal thereto (left-right direction or up-down direction), there is no change in the contact relationship between the intermediate terminals 335, 345 and the four terminals 351 to 354. In this state, the contact 335d and 351b are in contact, the contact 335c and 352a are in contact, the contact 345c and 353a are in contact, and the contact 345d and 354b are in contact. As a result of the contact of these contacts, a connection path from the positive input terminal 371 to the + output (plus output, positive terminal) of the cell units 356 and 357 is established, and a connection path from the negative input terminal 372 to the - output (minus output, negative terminal) of the cell units 356 and 357 is established. The two cell units 356 and 357 are connected in parallel, and the output thereof, that is, a direct current of rated 18 V, is output from the battery pack 300.

[0071] Fig. 20 shows the state before (1) the terminal part 380 is attached to the battery pack 300 and the state after attachment (2), and shows the connection state from the four terminals 351 to 354 to the cell units 356 and 357 in a circuit diagram. As shown in Fig. 20(1), when the terminal part 380 is not attached, the movable guide members 330 and 340 are biased by the spring 348 to move away from each other. In this state, the contact 335b and the contact 345b are separated and in a non-contact state. When the terminal part 380 is attached from the state of Fig. 20(1), the positive input terminal 381 contacts the inclined part 332 through the slit 321 (see Fig. 16). However, if the terminal part 380 is pushed in while in contact (or the battery pack 300 is moved toward the terminal part 380 side), the inclined part 332 moves so as to escape inside the positive input terminal 381, so that the movable guide member 330 moves in the direction of arrow 336 while compressing the spring 348. Similarly, when the negative input terminal 382 is pushed in while contacting the inclined part 342 through the slit 324 (see Fig. 16), the inclined part 342 moves so as to escape inside the negative input terminal 382, so that the movable guide member 340 moves in the direction of arrow 346 while compressing the spring 348. When the movable guide member 330 moves inward, the positive input terminal 381 enters between the parallel surface 333 located on the side of the inclined part 332 and the first + terminal 351, and is held in that state (the state shown in Fig. 20(2)) by the biasing of the spring 348, and the positive input terminal 381 makes good contact with the contact 351a of the first + terminal 351. Similarly, when the movable guide member 340 moves inward, the negative input terminal 382 enters between the parallel surface 343 located on the side of the inclined part 342 and the second - terminal 354, and is held in that state (the state shown in Fig. 20(2)), and the negative input terminal 382 makes good contact with the contact 354a of the second - terminal 354.

[0072] When the movable case internal members 330 and 340 move inward, the contact relationships of other contacts also change. First, when the contact 335b of the intermediate terminal 335 contacts the contact 345b of the intermediate terminal 345, the intermediate terminals 335 and 345 are in a conductive state. Also, the contact with the contact 335c of the intermediate terminal 335 switches from the contact 352a as shown in Fig. 20(1) to the contact 352b as shown in Fig. 20(2) of the same figure, and the connection state between the contact 335d of the intermediate terminal 335 and the contact 351b of the + terminal 351 is released. Similarly, the contact with the contact 345c of the intermediate terminal 345 switches from the contact 353a as shown in Fig. 20(1) of the same figure to the contact 353b as shown in Fig. 20(2) of the same figure, and the connection state between the contact 345d of the intermediate terminal 345 and the contact 354b of the - terminal 354 is released. As a result of the switching of the contact states of these contacts, a connection path from the positive input terminal 381 to the + output (plus output, positive terminal) of the cell unit 356 is established, a connection path from the - output (minus output, negative terminal) of the cell unit 356 to the + output of the cell unit 357 is established, and a connection path from the - output of the cell unit 357 to the negative input terminal 382 is established. This connection is a series connection of two cell units 356 and 357, and a DC of rated 36V is output from the battery pack 300. Since the movable case internal members 330 and 340 of the voltage switching mechanism 320 are biased by the spring 348, when the terminal portion 380 is removed from the state of Fig. 20(2), it returns to the original state of Fig. 20(1) of the same figure. Therefore, the series connection state of the cell units 356 and 357 is automatically released and returns to the parallel connection state.

[0073] As described above, by realizing the voltage switching mechanism 320 using the movable guide members 330 and 340, an operator can obtain an optimal output voltage for the electric device main body simply by attaching the battery pack 300 to either the electric device main body with a rated voltage of 18V or the electric device main body with a rated voltage of 36V. Incidentally, in the third embodiment described above, if the voltage ratio is 2, it can also be realized in a battery pack that switches other voltages, for example, 54V / 108V. Furthermore, a switching mechanism with a switching voltage ratio of 3 can be realized by using three movable guide members. In the battery pack 300 of the third embodiment, since the voltage switching mechanism 320 that functions as a voltage switching element and the contacts 335a and 345a that function as power supply terminals are arranged at positions substantially the same height in the vertical direction, the vertical size of the battery pack 300 can be configured to be compact.

Embodiment

[0074] Next, a fourth embodiment of the present invention will be described with reference to FIGS. 21 and 22. FIG. 21 is a top view of a battery pack 600 according to the fourth embodiment. The external shape of the battery pack 600 is substantially the same as that of the battery pack 100 shown in FIG. 7, and the shape of the rail portion, the shape of the lower surface 611, and the shape of the upper surface 615 are the same. A plurality of slot portions are provided on the upper surface 615, and the region where the slot portions are arranged becomes a terminal arrangement region. Here, as the slot portions, in addition to the positive terminal slot 621 and the negative terminal slot 622, a straight / parallel switching element slot 623 serving as a third slot is formed. The positive terminal slot 621 is a slot for accommodating the positive output terminal 661 (positive terminal), and the negative terminal slot 622 is a slot for accommodating the negative output terminal 662 (negative terminal). The straight / parallel switching element slot 623 is arranged in a portion sandwiched between the positive terminal slot 621 and the negative terminal slot 622. Here, a slot that was empty without any terminal assigned in a conventional battery pack is assigned to the straight / parallel switching element slot 623.

[0075] Inside the slot 623 for the series-parallel switching element, from the entrance side (front side), a parallel connector pair 663 composed of two parallel connectors 663a and 663b and a series connector 664 are arranged. The parallel connector 663a is composed of a pair of connectors (conductors), one connected to the + output (positive electrode) of the cell unit 356 and the other connected to the + output (positive electrode) of the cell unit 357. Similarly, the parallel connector 663b is composed of a pair of connectors (conductor pairs), one connected to the - output (negative electrode) of the cell unit 356 and the other connected to the - output (negative electrode) of the cell unit 357. In other words, the parallel connectors 663a and 663b are composed of a pair of connectors respectively connected to the same poles (+ output or - output) of each cell unit and arranged adjacent to each other. The parallel connectors 663a and 663b are each composed of a pair of conductors separated in the left-right direction, and in the normal state, the pair of conductors are in contact as shown in the figure. The connector (conductor) connected to the + output (positive electrode) of the cell unit 356 that constitutes the parallel connector 663a and the connector (conductor) connected to the + output (positive electrode) of the cell unit 357 that constitutes the parallel connector 663a each function as a switching terminal for switching the output voltage of the battery pack 600 to a low voltage. Also, the connector (conductor) connected to the - output (negative electrode) of the cell unit 356 that constitutes the parallel connector 663b and the connector (conductor) connected to the - output (negative electrode) of the cell unit 357 that constitutes the parallel connector 663b each function as a switching terminal for switching the output voltage of the battery pack 600 to a low voltage. The series connector 664 is composed of a pair of conductors separated in the left-right direction, and in the normal state, the left and right pairs of conductors are separated and in a non-contact state as shown in the figure. The series connector 664 is composed of a pair of connectors (conductor pairs), one connected to the + output (positive electrode) of the cell unit 356 and the other connected to the - output (negative electrode) of the cell unit 357. In other words, the series connector 664 is composed of a pair of connectors respectively connected to the different poles (+ output and - output) of each cell unit and arranged adjacent to each other. Incidentally, the series connector 664 may have a positional relationship with a distance in the mounting direction of the battery pack 600 in order to gain the distance between the terminals of the separated pair of conductors.The connector (conductor) connected to the + output (positive electrode) of the cell unit 356 that constitutes the series connector 664 and the connector (conductor) connected to the - output (negative electrode) of the cell unit 357 that constitutes the series connector 664 each function as a switching terminal for switching the output voltage of the battery pack 600 to a high voltage, and also function as series terminals for connecting a plurality of cell units 356 and 357 in series with each other.

[0076] The lengths in the mounting direction of the positive electrode terminal slot 621, the negative electrode terminal slot 622, and the other slots are LS, and the length LS1 in the mounting direction of the series-parallel switching element slot 623 is formed to be about twice as long as these. This is because inside the series-parallel switching element slot 623, three pairs of conductors of the parallel connectors 663a and 663b and the series connector 664 are arranged in series in the mounting direction. Here, the positive electrode output terminal 661 and the negative electrode output terminal 662 (collectively referred to as power supply terminals) are arranged apart in a direction intersecting the mounting direction, and in the region where these power supply terminals are arranged (specifically, the region from the step portion 612 to the length LS1 or LS2 (described later in FIG. 24) in the mounting direction, more specifically, the region of length LS), the parallel connector pair 663 and the series connector 664 that serve as voltage switching elements are arranged. In other words, the voltage switching elements are arranged in the region where the slot portion is provided.

[0077] FIG. 22 is a diagram showing the connection circuit of the cell units when the battery pack 600 is connected to the main body of the electrical device. (1) shows a state where it is connected to the main body of the electrical device for low voltage (for example, 18V), and (2) is a diagram showing a state where it is connected to the main body of the electrical device for high voltage (for example, 36V). In the main body of the electrical device for 18V, it has the same shape as the terminal portion 650 that has been conventionally used. That is, it has a positive electrode input terminal 651 and a negative electrode input terminal 652. The terminal portion 650 may be provided with input terminals (for example, LD terminals) other than those shown, but here only the part related to the characteristic configuration of the fourth embodiment will be described, and the description of other input terminals will be omitted. The LD terminal functions as a signal terminal for inputting or outputting information or signals.

[0078] The circuit diagram on the lower side of Fig. 22(1) shows a state where the terminal section 650 and the output terminal group of the battery pack 600 are connected when the battery pack 600 is attached to the main body of the electric device. Inside the battery pack 600, cell units 356 and 357 are configured, in which five lithium-ion battery cells are connected in series. In the state of (1), the + output and - output of the cell units 356 and 357 are connected in parallel and then connected to the positive output terminal 661 and the negative output terminal 662. That is, the + terminal of the cell unit 357 in which five cells are connected in series is connected to the positive output terminal 661, and the - terminal is connected to the negative output terminal 662 via the parallel connector 663b. On the other hand, the + terminal of the cell unit 356 in which five cells are connected in series is connected to the positive output terminal 661 via the parallel connector 663a, and the - terminal is connected to the negative output terminal 662. Here, the series connector 664 that connects the + terminal of the cell unit 356 and the - terminal of the cell unit 357 forms a series terminal group consisting of a plurality of contact terminals (the right terminal and the left terminal in the figure) in order to connect the plurality of cell units 356 and 357 in series, and the left and right contact terminals are in an open state (non-conductive state) in the initial state (the state where the battery pack 600 is removed).

[0079] The upper figure in Fig. 22(2) is a diagram showing the terminal shapes of the terminal section 680 of the electrical equipment main body for 36V. Here, in addition to the positive input terminal 681 and the negative input terminal 682 having the same shape as those conventionally used, a series-parallel switching terminal 683 is formed. The series-parallel switching terminal 683 is provided in the terminal arrangement area where the power supply terminals (positive output terminal 661, negative output terminal 662) are arranged in the battery pack mounting direction, and serves as a connection element for switching between parallel connection and series connection. The series-parallel switching terminal 683 is provided with two functions. When the battery pack 600 is mounted, the front-end side portion that first contacts the voltage switching elements (parallel connection pair 663, series connection element 664) is formed as a conduction terminal 683b made of a conductor, and the rear-end side portion is formed as a cutoff terminal 683a made of a non-conductor. The base portion of the terminal section 680 is formed by integrally molding synthetic resin, and the metal plate-like positive input terminal 681 and negative input terminal 682 are cast therein. The series-parallel switching terminal 683 includes a switching terminal group. The cutoff terminal 683a is integrally formed with the terminal section 680 from a non-conductive material, and a metal conduction terminal 683b is formed by casting molding at a part of its tip. Here, the cutoff terminal 683a is intended to enter between the parallel connection elements 663a and 663b that are in a contact state (conductive state) when the battery pack 600 is not mounted, thereby cutting off the conductive state of the parallel connection element 663a and cutting off the conductive state of the parallel connection element 663b. The cutoff terminal 683a is connected to the parallel connection elements 663a and 663b of the battery pack 600 constituted by a plurality of switching terminals, and functions as a switching element for switching the output voltage of the battery pack 600 to a low voltage. Conversely, the conduction terminal 683b is intended to enter between the series connection elements (series connection elements) 664 that are in a non-contact state (cutoff state) when the battery pack 600 is not mounted, and short-circuit them respectively to establish the conductive state of the series connection element 664. The conduction terminal 683b is connected to the series connection element (series connection element) 664 which is a switching terminal of the battery pack 600 constituted by a plurality of switching terminals, functions as a switching element for switching the output voltage of the battery pack 600 to a high voltage, and further functions as an integrated high-voltage connection element for connecting a plurality of cell units 356 and 357 in series with each other.Therefore, the conduction terminal 683b can be simply a metal plate and does not need to be connected to a substrate or the like on the power tool main body side. In this way, the series-parallel switching terminal 683, which is a voltage switching element, is configured by adjacently arranging switching terminals extending from each of a plurality of different cell units.

[0080] The circuit diagram on the lower side of FIG. 22(2) shows a state in which the terminal portion 680 and the output terminal group of the battery pack 600 are connected when the battery pack 600 is attached to the electric device main body. In the state of (2), a series connection circuit to the positive output terminal 661 and the negative output terminal 662 is established with the + output of the cell unit 356 and the - output of the cell unit 357 connected. The + terminal of the cell unit 357 in which five cells are connected in series is connected to the positive output terminal 661, and the - terminal is connected to the + terminal of the cell unit 356 through the connection of the series connector 664 that is short-circuited by the insertion of the conduction terminal 683b. The - terminal of the cell unit 356 is connected to the negative output terminal 662. Here, the parallel connectors 663a and 663b forming the parallel connector pair 663 are in a non-conducting state because the cutoff terminal 683a is interposed between the two contacts. While the parallel connection state of the cell units 356 and 357 as shown in (1) is eliminated, a series connection state is established.

[0081] According to the fourth embodiment as described above, by changing the shapes of the terminal portions 650 and 680 on the power tool main body side, in addition to the first slot 621 into which the positive input terminal 681 is inserted and the second slot 622 into which the negative input terminal 682 is inserted, the output voltage of the battery pack 600 can be appropriately switched by using the third slot 623 into which a switching element (series-parallel switching terminal 683) for switching the output voltage is inserted. Moreover, when the 18V output that has been widely used conventionally is adopted, the shape of the terminal portion 650 is the same as that of the conventional power tool, so the battery pack 600 according to this embodiment can be mounted on a conventionally commercially available 18V power tool main body or an electrical equipment main body and used in the same manner. On the other hand, in the case of a power tool main body or an electrical equipment main body that requires a rated voltage of 36V, if the shape of the terminal portion 680 is configured as shown in Fig. 22(2), a direct current of the rated voltage of 36V can be obtained from the battery pack 600 simply by mounting the battery pack 600. At this time, since there is no complicated switch mechanism, it has been possible to realize a voltage automatic switching type battery pack with good durability while suppressing an increase in manufacturing cost. Further, since the switching terminal group (663a, 663b, 664) serving as the voltage switching element is arranged in the third slot 623 within the region where the power supply terminals (positive output terminal 661 and negative output terminal 662) are arranged in the mounting direction, the voltage can be easily switched simply by mounting the battery pack on the electrical equipment main body. In particular, since the voltage switching element is arranged between the power supply terminals in a direction intersecting the mounting direction, it has become possible to mount the existing electrical equipment main body without increasing the size of the battery pack. In the fourth embodiment, since the voltage switching element and the power supply terminals are arranged at substantially the same height position in the vertical direction, the vertical size of the battery pack can be configured to be compact.Also, the connector (conductor) connected to the + output (positive electrode) of the cell unit 356 that constitutes the series connector 664 and the connector (conductor) connected to the - output (negative electrode) of the cell unit 357 that constitutes the series connector 664 each function as series terminals that connect a plurality of cell units 356 and 357 in series with each other. Since these series terminals are arranged at positions having substantially the same height in the vertical direction with respect to the positive electrode output terminal 661 that is the positive electrode terminal and the negative electrode output terminal 662 that is the negative electrode terminal, the vertical size of the battery pack can be configured to be compact.

[0082] FIG. 23 is a view showing the shape of a battery pack cover 640 that is attached when the battery pack 600 is not attached to the electric device body. The battery pack cover 640 is made of a non-conductive material such as vinyl chloride resin or other plastic materials, and is attached so as to cover the lower surface 611, the step portion 612, and the upper surface 615 of the battery pack 600. The battery pack cover 640 has a shape with a crank-shaped cross section when viewed from the side, in which an upper portion 643 as a first flat portion and a lower portion 641 as a second flat portion are connected by a vertical surface 642. Three vertical ribs 646 to 648 are formed so as to straddle the upper portion 643 and the vertical surface 642 of the battery pack cover 640. The vertical ribs 646 to 648 are formed at substantially the same position and the same size as the positive input terminals 651 and 681, the negative input terminals 652 and 682, and the series-parallel switching terminals 683, respectively. However, the plate thickness of the lower portion on the tip side of the vertical ribs 646 to 648 is formed to be slightly thinner to facilitate attachment. By attaching the battery pack cover 640 to the battery pack 600, the cell units 356 and 357 are in a completely electrically independent state. For example, when each of the cell units 356 and 357 has an electric energy of 54 Wh (= voltage 18 V × capacity 3.0 Ah), in the state without the battery pack cover 640, the cell units 356 and 357 are connected in parallel and the electric energy is 108 Wh (= voltage 18 V × capacity 3.0 Ah). Usually, when the electric energy of a lithium-ion battery pack exceeds 100 Wh, it is subject to transportation regulations. However, by attaching the battery pack cover 640, it becomes possible to handle two 54 Wh batteries, and it is not subject to transportation regulations and can be handled in a normal transportation form, thereby significantly reducing the packaging material and transportation cost.

[0083] On the outer peripheral side and near the longitudinal center line of the battery pack cover 640, an edge 644 and ribs 645 extending in the thickness direction (vertical direction) are integrally formed to enhance rigidity. When the vertical ribs 646 to 648 are attached to the battery pack cover 640, the vertical rib 646 is inserted into the positive terminal slot 621 and fitted with the positive input terminal 651, the vertical rib 647 is inserted into the negative terminal slot 622 and fitted with the negative input terminal 652, and the vertical rib 648 is inserted into the series-parallel switching element slot 623 and fitted with the parallel connectors 663a, 663b and the series connector 664. The battery pack cover 640 is held so as not to fall off from the battery pack 600 by using the spring properties of the positive input terminal 651, the negative input terminal 652, the parallel connectors 663a, 663b, etc.

[0084] As described above, in the battery pack 600 shown in FIGS. 21 to 23, the parallel connector pair 663 composed of two sets of parallel connectors 663a, 663b and the series connector 664 composed of a set of open contacts are arranged side by side in the mounting direction inside the series-parallel switching element slot 623. Therefore, as shown in FIG. 21, the length LS1 of the series-parallel switching element slot 623 in the mounting direction is longer than the length LS of the other slots. When the area corresponding to the length LS1 of the series-parallel switching element slot 623 becomes long, there is a risk that space cannot be secured during the actual mounting on the battery pack 600. In such a case, instead of arranging all of the series connector 664 and the parallel connectors 663a, 663b in one slot (the series-parallel switching element slot 623), they may be arranged dispersedly in two slots. FIGS. 24 and 25 are top views of the battery pack 600A showing the configuration (a modification of Example 4).

[0085] FIG. 24 is a top view of a battery pack 600A according to a modified example of the fourth embodiment. What has been changed in the external shape of the battery pack 600A are the first slot 623A and the second slot 624A for the series-parallel switch. A plurality of slot portions are provided on the upper surface 615, but the slot portion for signal transmission being used is changed to secure the second slot 624A as a series-parallel switch. In the first slot 623A, the parallel connector 673a is arranged on the side closer to the opening on the lower surface 611 side (the mounting direction inlet side), and the series connector 674 is arranged on the back side, so that these terminal pairs are arranged in series. On the other hand, in the second slot 624A, the parallel connector 673b is arranged at the back side away from the lower surface 611. The series connector 674, the parallel connectors 673a and 673b are each composed of a pair of conductors separated in the left-right direction. In a state where the battery pack 600A is not mounted, the parallel connectors 673a and 673b are in a contact state where the left and right conductor pairs are in contact, and the series connector 674 is in a non-contact state where the left and right conductor pairs are separated. By arranging in this way, the length of the first slot 623A and the second slot 624A in the mounting direction can be set to LS2, so that it can be configured shorter than the length LS1 of the series-parallel switching element slot 623 shown in FIG. 21, which is advantageous for implementation. Also, although not shown, on the opening side of the second slot 624A, it is possible to arrange as it is a connector for signal connection that has been conventionally arranged, such as a V terminal indicating the output of the battery, etc., so that the compatibility when connecting a power tool for 18V is not impaired. The connector for signal connection functions as a signal terminal for inputting or outputting information or signals.

[0086] FIG. 25 is a diagram showing a connection circuit of cell units when the battery pack 600A according to a modified example of the fourth embodiment is connected to the main body of an electric device. (1) shows a state where it is connected to the main body of an electric device for low voltage (e.g., 18V), and (2) is a diagram showing a state where it is connected to the main body of an electric device for high voltage (e.g., 36V). Compared with the configuration shown in FIG. 22, the shape of the terminal portion 650 of the electric device for low voltage (18V) is the same, but the shape of the terminal portion 680A of the electric device for high voltage (36V) is different. In the terminal portion 680 shown in FIG. 22, the series-parallel switching terminal 683 is composed of one piece, but in the terminal portion 680A of the modified example, as the series-parallel switching terminal, it is divided and arranged into a first series-parallel switching terminal 693 and a second series-parallel switching terminal 694. The tip side portion of the first series-parallel switching terminal 693 that first contacts the parallel connector 673b when the battery pack 600A is mounted is formed as a conduction terminal 693b made of a conductor, and the rear end side portion is formed as a cutoff terminal 693a made of a non-conductor. On the other hand, all of the second series-parallel switching terminal 694 is manufactured as a cutoff terminal made of a non-conductor. Here, the base portion of the terminal portion 680A is formed by integral molding of synthetic resin, and the metal plate-shaped positive input terminal 681 and negative input terminal 682 are cast therein. The cutoff terminal 693a of the first series-parallel switching terminal 693 and the second series-parallel switching terminal 694 may be made of synthetic resin integrally with the base portion.

[0087] The circuit diagram on the lower side of FIG. 25 shows a state in which the terminal portions 650 and 680A and the output terminal group of the battery pack 600A are connected by mounting the battery pack 600A on the main body of the electric device. In the state of (2), the + output of the cell unit 356 and the - output of the cell unit 357 are connected in series and connected to the positive output terminal 661 and the negative output terminal 662. The + terminal of the cell unit 357 in which five cells are connected in series is connected to the positive output terminal 661, and the - terminal is connected to the + terminal of the cell unit 356 via the series connector 674 which is short-circuited by inserting the conduction terminal 693b. The - terminal of the cell unit 356 is connected to the negative output terminal 662. Here, the parallel connectors 673a and 673b forming the parallel connector pair 673 are in a non-conductive state because the cut-off terminal 693a and the second series-parallel switching terminal (cut-off terminal) 694 are interposed between the two contacts respectively, and the parallel connection state between the cell units 356 and 357 as shown in (1) is eliminated. Here, the position viewed in the mounting direction of the parallel connector 673a is provided adjacent to the series connector 674 and not adjacent to the parallel connector 673b. This is to enable arranging the conventionally used signal transmission terminals on the entrance side of the parallel connector 673a. Incidentally, the parallel connectors 673a and 673b may be arranged together on the side of the first series-parallel switching terminal 693, and the series connector 674 may be arranged on the side of the second series-parallel switching terminal 694. However, in case the first series-parallel switching terminal 693 is damaged and detached from the terminal portion 680A and only the series connector 674 is connected by the action of the second series-parallel switching terminal 694, there is a risk of short circuit, so it is more advantageous to arrange as shown in this figure.

[0088] As described above, the advantages of the modified examples shown in FIGS. 24 and 25 are that the longitudinal length of the first series-parallel switching terminal 693 can be suppressed, and the length of the first slot 623A can also be suppressed in the same manner. At the base side of the second series-parallel switching terminal 694, it is also possible to maintain the conventional signal transmission terminal by casting a metal terminal. In addition, since the modification of the terminal portion 650 of the electrical equipment main body for low voltage (18V) is not required at all, the battery pack according to the present invention can be directly applied to the conventional electrical equipment main body. Incidentally, in the fourth embodiment, an example of a battery pack that outputs 18V and 36V with five cells as one cell unit for low voltage and high voltage has been described, but the output voltage can be arbitrarily set, and other combinations can be used as long as there is a potential difference of two times. For example, a battery pack can be realized in which 15 cells are used as one cell unit and switched between 54V (low voltage side) and 108V (high voltage side).

Embodiment

[0089] Next, a fifth embodiment of the present invention will be described with reference to FIGS. 26 to 28. In the battery pack 700 of the fifth embodiment, similar to the fourth embodiment, 18V and 36V can be automatically switched according to the terminal shape on the electric tool main body side. That is, when the battery pack 700 is attached to the electric tool main body or the electrical equipment main body, it automatically switches to the output voltage corresponding to the rated voltage on the main body side. FIG. 26 is a perspective view showing the external shape of the battery pack 700. This shape is compatible with the conventional battery pack 15 for rated 18V (see FIG. 1). In the battery pack 700, a plurality of slot portions are formed in a stepped raised portion at the boundary between the lower surface 111 and the upper surface 115, and the inside of these slot portions becomes a terminal arrangement region where a plurality of output terminals and signal terminals are arranged. The slot portions are notched not only in the direction parallel to the mounting direction but also in the vertical direction so that the terminals on the electric tool main body side can be inserted from the lower surface 111 side. In addition, an opening 709 that continuously opens in the horizontal direction is formed in the rear portion of the lower surface 111 below the slot portion. Among the plurality of slots formed in the region on the front side of the upper surface 115, FirstThe slot 701 houses a terminal pair for transmitting the + output on the battery pack side, the second slot 704 houses a terminal pair for transmitting the - output on the battery pack side, and the third slot 707 houses a series connection terminal pair for switching the output voltage of the battery pack 700 by arranging the - output from one cell unit and the + output from the other cell unit adjacent to each other in a non-contact state. In addition, the battery pack 700 has an LD terminal for outputting an over-discharge protection signal by a battery protection circuit (not shown) included in the battery pack 700, an LS terminal for outputting temperature information of the battery by a temperature-sensitive element (not shown) provided in contact with the cell, a V terminal for inputting a control signal from a charging device, a T terminal for outputting a signal serving as identification information of the battery pack 700 to a power tool body or a charging device, and slots such as a C+ terminal serving as a + terminal for charging are formed. The terminals arranged in these slots perform the same functions as those of the conventional battery pack 15 (see FIG. 1). The LD terminal, the LS terminal, and the T terminal function as signal terminals for inputting or outputting information or signals.

[0090] Figure 26(2) is a circuit diagram inside the battery pack 700. Inside the battery pack 700, two sets of cell units 356 and 357 are accommodated, in which five lithium-ion battery cells such as 14500 or 18650 are connected in series. The + output of the cell unit 356 is connected to the positive terminal 712, and the + output of the cell unit 357 is connected to the positive terminal 713. The positive terminals 712 and 713, which form a parallel positive terminal pair, are fixed to the terminal board 711 adjacent to each other and are fixed so as to be located within the slot 701. The positive terminals 712 and 713 function as positive terminals, and further function as switching terminals for switching the output voltage of the battery pack 700 to a low voltage, and also function as parallel terminals for connecting a plurality of cell units in parallel to each other. And the plurality of positive terminals 712 and 713 that function as parallel terminals are arranged adjacent to each other and are configured as a parallel terminal group. Similarly, the - output of the cell unit 357 is connected to the negative terminal 715, and the - output of the cell unit 356 is connected to the negative terminal 716. The negative terminals 715 and 716 function as negative terminals, and further function as switching terminals for switching the output voltage of the battery pack 700 to a low voltage, and also function as parallel terminals for connecting a plurality of cell units in parallel to each other. And the plurality of positive terminal electrodes 715 and 716 that function as parallel terminals are arranged adjacent to each other and are configured as another parallel terminal group. The negative terminals 715 and 716, which form a parallel negative terminal pair, are fixed to the terminal board 714 adjacent to each other and are fixed so as to be located within the slot 704. In this embodiment, further, a series connection terminal 718 connected from the + output of the cell unit 357 and a series connection terminal 719 connected from the - output of the cell unit 356 are arranged within the slot 707 as a series connection terminal pair. The series connection terminals 718 and 719 function as switching terminals for switching the output voltage of the battery pack 700 to a high voltage, and also function as series terminals for connecting a plurality of cell units 256 and 357 in series to each other. And the plurality of series connection terminals 718 and 719 that function as series terminals are arranged adjacent to each other and are configured as a series terminal group.These positive terminals 712 and 713 and negative terminals 715 and 716 are configured to be adjacent and separated so as to extend from respective ones of a plurality of different cell units 356 and 357, and thus function as a voltage switching element that switches between parallel connection and series connection of the cell units 356 and 357.

[0091] When the battery pack 700 is not attached to the power tool main body or the charger, as shown in the circuit diagram of FIG. 26(2), the positive terminals 712 and 713 are in a non-contact state, the negative terminals 715 and 716 are in a non-contact state, and the series connection terminals 718 and 719 are in a non-contact state. The series connection terminals 718 and 719 are used in a pair and are fixed to the terminal board 717 adjacent to each other. Note that the terminal boards 711, 714, and 717 may be an integral board, or may be shared with a protection circuit board provided with a battery protection circuit. The positive terminals 712, 713, the negative terminals 715, 716, and the series connection terminals 718, 719 constitute a switching terminal group. The positive terminals 712, 713 constitute a positive terminal pair or a parallel positive terminal group (parallel terminal group), the negative terminals 715, 716 constitute a negative terminal pair or a parallel negative terminal group, and the series connection terminals 718, 719 constitute a series connection terminal group (series terminal group).

[0092] FIG. 27 is a diagram showing a state where the battery pack 700 is connected to a conventional electric tool body with a rated voltage of 18V, and (1) is a circuit diagram at the time of connection. Here, the positive input terminal 721 on the electric tool body side contacts the positive terminals 712 and 713, and the negative input terminal 722 contacts the negative terminals 715 and 716, thereby forming a parallel connection circuit of the cell units 356 and 357. The positive input terminal 721 and the negative input terminal 722 function as a switching element or a connecting element for switching the output voltage of the battery pack 700 to a low voltage, and also function as a switching element for low voltage for connecting a plurality of cell units in parallel to each other. (3) is a side view of the positive terminals 712 and 713 and the shape of the positive input terminal 721 of the terminal portion 720 on the electric tool body side for a rated 18V attached thereto, and (2) is a top view of the positive terminals 712 and 713. Here, the positive input terminal 721 of the terminal portion 720 has the same shape as that of a conventional electric tool and is a metal plate with a height H. The region where the positive input terminals 721 of the positive terminals 712 and 713 contact is formed by an elongated plate-like member having a height in the vertical direction of H / 2 or less. The positive terminal 712 extends upward from the terminal board 711 on the side farther from the positive input terminal 721 (the side opposite to the opening of the slot), and extends toward the positive input terminal 721 side (the opening of the slot) above the positive terminal 713. On the other hand, the positive terminal 713 has a shape in which the upper portion of the conventional positive terminal is cut off to lower the height, and the positive terminals 712 and 713 are provided spaced apart from each other so as not to contact each other. The positive input terminal 721 is formed of a metal plate cast into a synthetic resin terminal portion 720 on the electric tool body side.

[0093] The positive electrode terminal 712 is formed in a shape where a flat plate is bent into a U shape, with a fold at the open end, and the folded portions contact each other to close the open end. Similarly, the positive electrode terminal 713 is also formed in a shape where a flat plate is bent into a U shape, with a fold at the open end, and the folded portions contact each other to close the open end. The positive electrode terminal 713 is configured to be shorter in its front-to-back length to nearly half that of the positive electrode terminal 712, but the shape in top view of the front side portion L is formed to be the same as the corresponding portion of the positive electrode terminal 712. Thus, a plurality of positive electrode terminals are arranged adjacent to each other within the first slot 701 to form a positive electrode terminal group. When the battery pack 700 is attached to the battery pack mounting portion of the power tool body, the positive input terminal 721 is press-fitted in such a way as to expand the open ends of the positive electrode terminals 712 and 713, and a part of the upper region of the positive input terminal 721 contacts the positive electrode terminal 712, and a part of the lower region contacts the positive electrode terminal 713. As a result, the positive electrode terminals 712 and 713 are short-circuited by the positive input terminal 721. The terminal structures shown in FIGS. 27(2) and (3) are the same for the negative electrode terminals 715 and 716. That is, the negative electrode terminal 715 has the same shape as the positive electrode terminal 712, the negative electrode terminal 716 has the same shape as the positive electrode terminal 713, and the negative input terminal 722 has the same shape as the positive input terminal 721. A plurality of negative electrode terminals are arranged adjacent to each other within the second slot 704 to form a negative electrode terminal group. Therefore, when the battery pack 700 is attached to the terminal portion 720 on the power tool body side, a positive electrode terminal pair and a negative electrode terminal pair are respectively connected to the positive input terminal 721 and the negative input terminal 722, and the cell units 356 and 357 are connected in parallel, and its rated output is 18V.

[0094] FIG. 27(4) is a front view showing the shape of the terminal portion 720 on the power tool main body side, and (5) is a perspective view of the terminal portion 720. The terminal portion 720 is manufactured by integrally molding a non-conductive material such as synthetic resin, and three metal terminals, namely a positive input terminal 721, a negative input terminal 722, and an LD terminal 723, are cast therein and firmly fixed. As can be seen from (5), the LD terminal 723 is configured to be larger than the positive input terminal 721 and the negative input terminal 722, which is for stably holding the battery pack 700 to be mounted. The terminal portion 720 has not only a vertical surface 720b that serves as a butting surface in the mounting direction, but also a horizontal surface (upper surface as viewed from the terminals 721 to 723) 720a. The horizontal surface 720a becomes a surface that slides facing the upper surface 115 when the battery pack 700 is mounted.

[0095] FIG. 28 is a diagram showing a state in which the battery pack 700 is connected to a new-rated 36V power tool body, and (1) is a circuit diagram at the time of connection. Here, the positive input terminal 731 on the power tool body side with a rated voltage of 36V is made to contact only the positive terminal 712 and not the positive terminal 713. Similarly, the negative input terminal 732 is also made to contact only the negative terminal 715 and not the negative terminal 716. On the other hand, by inserting a metal conduction terminal (short-circuiting element) 734 provided additionally in the terminal portion 730 between the series connection terminals 718 and 719, the series connection terminals 718 and 719 arranged in a non-contact state are short-circuited. As a result of connecting the series connection terminals 718 and 719 using such a short-circuiting element, the - output of the cell unit 356 and the + output of the cell unit 357 are connected, and as can be understood from the circuit diagram in FIG. (1), the series outputs of the cell units 356 and 357 are connected to the positive input terminal 731 and the negative input terminal 732. The conduction terminal (short-circuiting element) 734 functions as a switching element for switching the output voltage of the battery pack 700 to a high voltage, and also functions as a connection element for high voltage for connecting a plurality of cell units 356 and 357 in series with each other. In FIGS. (2) and (3), the terminal shapes on the battery pack 700 side, that is, the shapes of the positive terminals 712 and 713 and the shapes of the negative terminals 715 and 716 of the same type are not changed at all from the terminal shapes shown in FIG. 27. However, the terminal shape of the terminal portion 730 is devised. On the right side of (3), in the positive input terminal 731 of the terminal portion 730, the portion corresponding to the positive terminal 712 has the metal portion exposed, but the portion corresponding to the positive terminal 713 is replaced with an insulating terminal material or a part of the positive terminal 713 is covered with an insulating material to form a plate-shaped insulating terminal 735. As a result, the positive input terminal 731 conducts only to the positive terminal 712 and does not conduct to the positive terminal 713, so that the + output of the cell unit 356 is connected to the positive input terminal 731 on the power tool body side, and the + output of the cell unit 357 is not connected (shown by a dotted line in FIG. 28(1) because it is not connected). The negative input terminal 732 on the power tool body side also has exactly the same terminal shape as the positive input terminal 731 as shown in FIGS. (4) and (5).An insulating terminal 736 is provided at the lower portion of the negative input terminal 732 so that the negative input terminal 732 and the negative terminal 716 do not conduct when the terminal portion 730 is attached to the battery pack 700. Therefore, the - output of the cell unit 357 is connected to the negative input terminal 732 on the electric tool main body side, but the - output of the cell unit 356 is not connected.

[0096] FIG. 28(4) is a front view showing the shape of the terminal portion 730 on the electric tool main body side, and (5) is a perspective view of the terminal portion 730. The terminal portion 730 is characterized in that the vertical width is formed to be thinner so that the positive input terminal 731 and the negative input terminal 732 contact only the positive terminal 712 and the negative terminal 715 arranged on the upper side, respectively, compared to the terminal portion 720 shown in FIG. 27. Further, an insulating terminal 735 made of synthetic resin is formed in the lower portion of the positive input terminal 731, and an insulating terminal 736 made of synthetic resin is formed in the lower portion of the negative input terminal 732. The insulating terminals 735 and 736 can be formed integrally with the terminal portion 730, and the rear end side is connected to the vertical surface 730b. Here, by configuring the thickness of the plate-shaped insulating terminals 735 and 736 to be thicker than that of the positive input terminal 731 and the negative input terminal 732, when the synthetic resin portion of the terminal portion 730 including the insulating terminals 735 and 736 is molded, the lower halves of the metal positive input terminal 731 and the negative input terminal 732 can be cast into the synthetic resin to be in an insulating state.

[0097] A conduction terminal 734 is further added to the terminal unit 730. The position where the conduction terminal 734 is provided is arbitrary. Here, since the series connection terminals 718 and 719 are provided by using an empty slot portion (slot 707 in FIG. 26) that has not been used in the conventional 18V battery pack, the conduction terminal 734 is located next to the positive input terminal 731. The conduction terminal 734 is made of a metal plate. While a part of the positive input terminal 731, the negative input terminal 732, and the LD terminal 733 have wiring connection portions 731a, 732a, and 733a for wiring inside the electric device body, the conduction terminal 734 does not require a wiring connection portion. This is because the conduction terminal 734 is only used to short-circuit the series connection terminals 718 and 719. Incidentally, it may be configured to perform signal transmission using the conduction terminal 734. In that case, it is advisable to form a wiring connection portion. The wiring connection portions 731a, 732a, and 733a are arranged so as to be offset inward from the positions of the positive input terminal 731, the negative input terminal 732, and the LD terminal 733 as seen in the figure of FIG. 28(4). This is because the metal plates forming the positive input terminal 731, the negative input terminal 732, and the LD terminal 733 are bent in a crank shape so as to have a step, and the bent portion is configured to be cast with a synthetic resin.

[0098] In the fifth embodiment, by simply changing the shape of the terminal portion on the power tool main body side to the shape in FIG. 27 (terminal portion 720) or the shape in FIG. 28 (terminal portion 730), the output voltage from the battery pack 700 can be easily changed from 18V to 36V. Moreover, since no movable members such as switch means are used in the battery pack 700, a battery pack with a simple structure and high durability can be realized. Further, the positive terminals 712, 713, the negative terminals 715, 716, and the series connection terminals 718, 719 can be mounted in the existing slot portions of the 18V battery pack, so a voltage-switchable battery pack with a size compatible with the conventional one can be realized. As described above, the structure of the fifth embodiment has been explained with reference to FIGS. 27 and 28. However, these structures, particularly the terminal shapes, can be variously deformed. In the fifth embodiment, since the voltage switching element and the power supply terminal are arranged at positions having substantially the same height in the vertical direction, the vertical size of the battery pack can be configured to be compact. Also, since the series connection terminals 718, 719 that function as series terminals, the positive terminals 712, 713, and the negative terminals 715, 716 are arranged at positions having substantially the same height in the vertical direction, the vertical size of the battery pack can be configured to be compact.

[0099] FIG. 29 is a diagram showing Modification 1 in which only the terminal portion of the 36V power tool main body is changed. In FIG. 29, only the shape of the terminal portion 750 is different. A configuration is adopted in which a cutoff terminal as shown in FIG. 28 is not provided below the positive input terminal 751, and nothing contacts the positive terminal 713 when the battery pack is mounted. As can be seen from FIGS. (3) and (4) of the same figure, a configuration is also adopted in which a cutoff terminal is not provided below the negative input terminal 752. The shapes of the conduction terminal 754 and the LD terminal 753 are the same as those in FIG. 28. Even with the terminal portion 750 as described above, the same effect as that of FIG. 28 can be obtained.

[0100] FIG. 30 is a diagram showing Modification 2 in which only the terminal portion of the electric tool body for 36V is changed. The basic configuration is the same as that of FIG. 29, and the positive terminals 712 and 713 are arranged side by side in a direction intersecting the insertion direction of the battery pack 700, here in the vertical direction so as not to contact. The terminal portion 770 for 36V is formed with a positive input terminal 771 having an appropriate vertical width for contacting only the positive terminal 712, and an insulating plate 775 extending horizontally is formed so as to contact the lower edge portion of the positive input terminal 771. The insulating plate 775 enters between the vertical gaps 777 between the positive terminal 712 and the positive terminal 713 when the battery pack 700 is mounted, and has an effect of almost completely preventing the short circuit between the positive terminal 712 and the positive terminal 713 due to the presence of dust and foreign matter during the operation of the electric tool, and keeping the insulation state between the positive terminal 712 and the positive terminal 713 good. The shape of the negative input terminal 772 is also formed exactly the same as that of the positive input terminal 771, and when viewed in the direction parallel to the insertion direction of the battery pack as shown in (3), an insulating plate 776 having a predetermined width in the horizontal direction is formed on the negative input terminal 772. There is no change in the shapes of the conduction terminal 774 and the LD terminal 773. When viewed in the figure of (4), the insulating plates 775 and 776 below the positive input terminal 771 and the negative input terminal 772 are connected to the vertical surface 770b of the terminal portion 770. It is desirable that the horizontal widths of the insulating plates 775 and 776 extend to the vicinity of the boundary with the adjacent slot, but they may be smaller than that. Here, the insulating plates 775 and 776 can be manufactured integrally with the terminal portion 770, and in this case, the positive input terminal 771 and the negative input terminal 772 are fixed by die casting.

[0101] FIG. 31 is a diagram showing Modification Example 3 in which both the terminal shape on the battery pack side for 36V and the terminal portion 790 on the electric tool body side are changed. The positive terminals 782 and 783 are arranged on the terminal board 781 side by side in the same direction as the insertion direction of the battery pack 700 and in a non-contact state. The upper portions 782a and 783a of the positive terminals 782 and 783 are arranged separated in the mounting direction as shown in the top view of (1), and the positive input terminal 721 to be inserted is shaped so as to be able to penetrate from the inlet side 787a to the outlet side 787b. The lower portions 782b and 783b of the positive terminals 782 and 783 are formed in a U shape with the left and right sides connected, and can be easily manufactured by pressing a single metal plate.

[0102] The shapes of the positive input terminal 721 and the negative input terminal 722 inserted into the pair of positive terminals (782, 783) and the pair of negative terminals of the same shape do not need to be changed from the shape shown in FIG. 27 as shown in FIGS. 31(2) and (3) in the electric tool body with a rated voltage of 18V. On the other hand, in the electric tool body with a rated voltage of 36V, it is necessary to change the shape of the terminal portion 790. The terminal portion 790 is arranged such that the insulating plate 795 and the positive input terminal 791 are aligned in the insertion direction of the battery pack. That is, compared with the terminal portion 720 for 18V rating, the exposed area of the positive input terminal 791 is made about half that of the positive input terminal 721, so that at the time of 36V output, the positive input terminal 791 contacts only the positive terminal 782 and is not electrically connected to the positive terminal 783. The configuration on the negative input terminal 792 side is also configured in the same manner as the positive input terminal 791 side, and an insulating plate 796 is formed adjacent to the negative input terminal 792 as shown in (4) and (5). The insulating plates 795 and 796 can be integrally manufactured by injection molding of synthetic resin together with the base portion of the terminal portion 790. As described above, also in Modification Example 3, a voltage-switchable battery pack compatible with the conventional 18V equipment could be realized.

[0103] FIG. 32 is a view showing Modification Example 4 in which only the terminal portion 800 of the electric tool body for 36V is changed. This embodiment has a shape in which the insulating plate 795 in the example shown in FIG. 31 is removed. The length of the positive input terminal 801 in the mounting direction is made slightly shorter than half of the length of the positive input terminal 721 (see FIG. 27) for 18V. Similarly, the length of the negative input terminal 802 in the mounting direction is made slightly shorter than half of the length of the negative input terminal 722 for 18V. The shape of the terminal portion 800 is equivalent to that of the terminal for 18V except that there is a conduction terminal 804 when viewed from the rear as shown in FIG. 32(3). It will be clear from the perspective view in FIG. 4(4) that the positive input terminal 801 and the negative input terminal 802 are shorter in the front-rear direction than the other terminals (803, 804).

[0104] FIG. 33 is a view showing Modification Example 5 in which the shapes of the positive terminal pair and the negative terminal pair on the battery pack side are changed. These positive terminals 812 and 813 have a shape in which only one side of the positive terminals 712 and 713 shown in FIG. 27 is eliminated. The positive terminal 812 forms only the right half, and the positive terminal 813 forms only the left half. Since they are separated in the vertical direction when viewed in side view as shown in (2), there is no risk of the positive terminals 812 and 813 coming into contact when the positive input terminal 721 or 731 is not inserted. Although not shown here, the shape on the negative terminal side and the shape of the terminal pair for series connection can be configured in the same way. The terminal portion 720 for 18V to be mounted on this terminal has the same shape as that shown in FIG. 27, and the shape of the terminal portion 730 for 36V has the same shape as that shown in FIG. 28. In this Modification Example 5, it is possible to reduce the weights of the positive terminal, the negative terminal, and the terminal pair for series connection, and thus reduce the weight of the battery pack.

[0105] FIG. 34 is a view showing Modification Example 6 in which only the terminal portion 750 for 36V is changed from Modification Example 5 of FIG. 33. The shape of this terminal portion 750 is the same as the shape shown in FIG. 29, and the vertical widths of the positive input terminal 751 and the negative input terminal 752 are narrowed. By forming it in this way, when the terminal portion 750 for 36V is contacted, the series output of the cell units 356 and 357 can be obtained from the battery pack.

[0106] FIG. 35 is a diagram showing a modification 7 in which only the terminal portion 770 for 36V is changed from modification 5 of FIG. 33. The shape of this terminal portion 770 is the same as the shape shown in FIG. 30. The vertical width of the positive input terminal 771 is narrowed, and an insulating plate 775 extending in the horizontal direction is formed so as to contact the lower edge portion of the positive input terminal 771. The configuration on the negative input terminal 772 side is also the same as the structure shown in FIG. 30.

[0107] As described above, in the fifth embodiment, in a battery pack capable of switching the output voltage, without relying on a switching mechanism having a plurality of movable members, a plurality of divided positive terminal pairs and negative terminal pairs are provided, and a series connection terminal pair for connecting two cell units 356 and 357 in series is provided. Therefore, a battery pack capable of easily switching the voltage can be realized simply by selecting whether the shape of the terminal portion side of the electrical equipment main body is for 18V or 36V. In addition, since it is not necessary to mount a complicated switch mechanism in the battery pack, the number of parts can be reduced, the assemblability can be improved, and the battery pack can be downsized while maintaining compatibility.

[0108] The above-described first to fifth embodiments can be variously modified. In the above-described embodiments, the voltage switching between 18V and 36V is supported, but other voltage ratios may also be used.

Embodiment

[0109] FIG. 36 is a diagram for explaining the state of mounting a battery pack according to a sixth embodiment on a power tool. A power tool, which is a form of an electric device, has a battery pack and drives a tip tool or a working device using a rotational driving force by a motor. Although various types of power tools are realized, the power tool main bodies 1001 and 1030 shown in FIG. 36 are both called impact tools. The power tool main bodies 1001 and 1030 are tools that perform tightening work by applying a rotational force and an axial impact force to a tip tool such as a bit or a socket wrench (not shown). These power tool main bodies 1001 and 1030 include housings 1002 and 1032 that form the outer shape, and handle portions 1003 and 1033 are formed on the housings 1002 and 1032. Trigger-like operation switches 1004 and 1034 are provided in the vicinity where the index finger touches when the operator grips a part of the handle portions 1003 and 1033, and battery pack mounting portions 1010 and 1040 for mounting the battery packs 1015 and 1100 are formed below the handle portions 1003 and 1033.

[0110] The power tool main body 1001 is a conventional electric device that uses a battery pack 1015 with a rated voltage of 18V. The battery pack 1015 is a conventional battery pack and can be mounted on the battery pack mounting portion 1010 of an 18V-compatible electric device (power tool main body 1001) like the combination of arrow a. Inside the battery pack 1015, only one set of a cell unit formed by connecting five lithium-ion battery cells with a rated voltage of 3.6V in series is accommodated, or two sets of such cell units are accommodated and connected in parallel to each other. The voltage of 18V is sometimes called a low voltage in the sense that it is a relatively low voltage. Similarly, the power tool main body 1001 or the electric device main body with a rated voltage of 18V may be called a low-voltage power tool main body or a low-voltage electric device main body, respectively. Similarly, the battery pack 1015 with a nominal voltage of 18V may be called a low-voltage battery pack.

[0111] The power tool main body 1030 is an electrical equipment main body with a rated voltage of 36V. As shown by the arrow b1, a battery pack 1100 capable of outputting 36V is mounted on the battery pack mounting portion 1040. The voltage of 36V is sometimes referred to as a high voltage here in the sense that it is a relatively high voltage. Similarly, the power tool main body 1030 or the electrical equipment main body with a rated voltage of 36V may sometimes be referred to as a high-voltage power tool main body or a high-voltage electrical equipment main body, respectively. Inside the battery pack 1100, two sets of cell units in which five 3.6V lithium-ion battery cells are connected in series are accommodated. By changing the connection method of the two sets of cell units, both 18V output and 36V output can be switched. In the sixth embodiment, the battery pack 1100 is configured to support two voltages, enabling low-voltage and high-voltage outputs. Thus, as shown by the arrow b2, the battery pack 1100 can be mounted on the 18V-compatible power tool main body 1001, and as shown by the arrow b1, it can also be mounted on the 36V-compatible power tool main body 1030. In this way, the battery pack 1100 that enables low-voltage and high-voltage outputs may sometimes be referred to as a voltage-variable battery pack here. In order to mount the battery pack 1100 on power tool main bodies 1001 and 1030 with different voltages as shown by the arrows b1 and b2, it is important to make the shapes of the rail portions and terminal portions of the battery pack mounting portions 1010 and 1040 substantially the same, and to make the output voltage of the battery pack 1100 switchable. At this time, it is important to ensure that the output voltage of the battery pack 1100 corresponds exactly to the rated voltage of the mounted electrical equipment main body or power tool main body to prevent voltage setting errors.

[0112] FIG. 37 is a perspective view showing the shape of the battery pack mounting portion 1010 of the power tool main body 1001. The power tool main body 1001 shown here is an impact driver, and a handle portion extending downward from the body portion of the housing 1002 is provided, and the battery pack mounting portion 1010 is formed below the handle portion. A trigger switch 1004 is provided on the handle portion. An anvil (not shown), which is an output shaft, is provided on the front side of the housing 1002, and a tip tool holding portion 1008 for mounting a tip tool 1009 is provided at the tip of the anvil. Here, a plus driver bit is mounted as the tip tool 1009. Not limited to power tools only, in all electric devices using a battery pack, a battery pack mounting portion 1010 corresponding to the shape of the mounted battery pack is formed so that a battery pack that does not fit the battery pack mounting portion 1010 cannot be mounted. In the battery pack mounting portion 1010, rail grooves 1011a and 1011b extending in parallel in the front-rear direction are formed on the inner wall portions on both the left and right sides, and a terminal portion 1020 is provided between them. The terminal portion 1020 is manufactured by integrally molding a non-conductive material such as synthetic resin, and a plurality of metal terminals, for example, a positive input terminal 1022, a negative input terminal 1027, and an LD terminal (abnormal signal terminal) 1028 are cast therein. The LD terminal (abnormal signal terminal) 1028 functions as a signal terminal for inputting or outputting information or a signal. The terminal portion 1020 has a vertical surface 1020a that serves as a butting surface in the mounting direction (front-rear direction), and a horizontal surface 1020b. The horizontal surface 1020b is adjacent to and faces the upper surface 1115 (described later in FIG. 38) when the battery pack 1100 is mounted. A curved portion 1012 that contacts the raised portion 1132 (described later in FIG. 38) of the battery pack 1100 is formed on the front side of the horizontal surface 1020b, and a protrusion 1014 is formed near the center of the left and right of the curved portion 1012. The protrusion 1014 also serves as a boss for screwing the housing of the power tool main body 1001 that is divided into two in the left-right direction, and also serves as a stopper for restricting the relative movement of the battery pack 1100 in the mounting direction.

[0113] FIG. 38 is a perspective view of a battery pack 1100 according to a sixth embodiment of the present invention. The battery pack 1100 can be attached to and detached from battery pack mounting portions 1010 and 1040 (see FIG. 36), and the output of low voltage (here 18V) and high voltage (here 36V) is automatically switched according to the terminal shape on the side of the power tool main body 1001 or 1030. In order to have compatibility in attachment with the conventional battery pack 1015 for rated 18V (see FIG. 36), the shape of the mounting portion of the battery pack 1100 is the same as that of the conventional battery pack 1015. The housing of the battery pack 1100 is formed by a lower case 1101 and an upper case 1110 that can be divided in the vertical direction. The lower case 1101 and the upper case 1110 are members that do not conduct electricity, for example, made of synthetic resin, and are fixed to each other by four screws. The upper case 1110 is formed with a mounting mechanism in which two rails 1138a and 1138b are formed for attachment to the battery pack mounting portion 1010. The rails 1138a and 1138b are formed so as to extend in a direction parallel to the mounting direction of the battery pack 1100 and project from the left and right side surfaces of the upper case 1110. The front end portions of the rails 1138a and 1138b are open ends, and the rear end portions are closed ends connected to the front side wall surface of the raised portion 1132. The rails 1138a and 1138b are formed in a shape corresponding to the rail grooves 1011a and 1011b (see FIG. 37) formed in the battery pack mounting portion 1010 of the power tool main body 1001. When the rails 1138a and 1138b are fitted into the rail grooves 1011a and 1011b, the battery pack 1100 is fixed to the power tool main body 1001 by locking with locking portions 1142a (the right locking portion and not visible in FIG. 38) and 1142b that serve as the claws of the latch. When removing the battery pack 1100 from the power tool main body 1001, by pushing the latches 1141 on both the left and right sides, the locking portions 1142a and 1142b move inward and the locked state is released, and in that state, the battery pack 1100 is moved in the direction opposite to the mounting direction.

[0114] On the front side of the upper case 1110, a flat lower surface 1111 is formed, and an upper surface 1115 which is formed higher than the lower surface 1111 is formed near the center. The lower surface 1111 and the upper surface 1115 are formed in a stepped shape, and their connecting portion is a stepped portion 1114 which is a vertical surface. The front side portion of the upper surface 1115 from the stepped portion 1114 becomes a slot group arrangement region 1120. In the slot group arrangement region 1120, a plurality of slots 1121 to 1128 extending rearward from the front stepped portion 1114 are formed. The slots 1121 to 1128 are portions cut out so as to have a predetermined length in the battery pack mounting direction, and the inside of this cut-out portion becomes a terminal arrangement region, and a plurality of connection terminals (described later in FIG. 39) that can be fitted to the device-side terminals of the power tool main bodies 1001 and 1030 or an external charging device (not shown) are arranged. The slots 1121 to 1128 are not only cut out on the upper surface parallel to the mounting direction but also on the vertical surface so that the terminals on the power tool main body side can be inserted from the lower surface 1111 side. Further, below the slots 1121 to 1128, an opening 1113 that continuously opens in the lateral direction is formed between the lower surface 1111 and the slots.

[0115] Slots 1121 to 1128 are such that the slot 1121 closer to the right rail 1138a of the battery pack 1100 serves as the insertion port for the charging positive electrode terminal (C+ terminal), and the slot 1122 serves as the insertion port for the discharging positive electrode terminal (+ terminal). Also, the slot 1127 closer to the left rail 1138b of the battery pack 1100 serves as the insertion port for the negative electrode terminal (- terminal). In the battery pack 1100, generally, the positive electrode side and the negative electrode side of the power terminals are arranged so as to be sufficiently separated. Looking from the vertical virtual plane located at the center of left and right, the positive electrode terminal is provided at a sufficiently separated position on the right side, and the negative electrode terminal is provided at a sufficiently separated position on the left side. Between the positive electrode terminal and the negative electrode terminal, a plurality of signal terminals for signal transmission to the battery pack 1100, the power tool main bodies 1001, 1030, and an external charging device (not shown) are arranged. Here, four slots 1123 to 1126 for signal terminals are provided between the power terminal group. The slot 1123 is a spare terminal insertion port, and no terminal is provided in the sixth embodiment. The slot 1124 is an insertion port for a T terminal for outputting a signal serving as the identification information of the battery pack 1100 to the power tool main body or the charging device. The slot 1125 is an insertion port for a V terminal for inputting a control signal from an external charging device (not shown). The slot 1126 is an insertion port for an LS terminal for outputting the temperature information of the battery by a thermistor (temperature sensing element) provided in contact with the cell and not shown. On the left side of the slot 1127 serving as the insertion port for the negative electrode terminal (- terminal), a slot 1128 for an LD terminal for outputting an abnormal stop signal by a battery protection circuit, which will be described later and is included in the battery pack 1100, is further provided.

[0116] On the rear side of the upper surface 1115, a raised portion 1132 is formed to bulge. The outer shape of the raised portion 1132 is a shape that bulges above the upper surface 1115, and a recessed stopper portion 1131 is formed near the center thereof. The stopper portion 1131 serves as a butting surface for the protruding portion 1014 (see FIG. 37) when the battery pack 1100 is mounted on the battery pack mounting portion 1010. When inserted until the protruding portion 1014 on the electric power tool main body 1001 side abuts against the stopper portion 1131, a plurality of terminals (device-side terminals) arranged on the electric power tool main body 1001 and a plurality of connection terminals (described later with reference to FIG. 39) arranged on the battery pack 1100 come into contact with each other to be in a conductive state. Further, the locking portions 1142a (the right locking portion, not visible in FIG. 38) and 1142b of the latch 1141 of the battery pack 1100 pop out vertically outward at the lower portions of the rails 1138a and 1138b due to the action of a spring and engage with recesses (not shown) formed in the rail grooves 1011a and 1011b of the electric power tool main body 1030, thereby preventing the battery pack 1100 from falling off. Inside the stopper portion 1131, a slit 1134 serving as an intake port for cooling air connected to the inside of the battery pack 1100 is provided. Further, in a state where the battery pack 1100 is mounted on the electric power tool main body 1001, the slit 1134 is covered so as not to be visible from the outside and is in a closed state. The slit 1134 is a wind window used to forcibly flow cooling air into the inside of the battery pack 1100 when the battery pack 1100 is connected to a charging device (not shown) for charging. The cooling air taken into the battery pack 1100 is discharged to the outside through a slit 1104 serving as an exhaust wind window provided on the front wall of the lower case 1101.

[0117] FIG. 39 is a perspective view of the battery pack 1100 of FIG. 38 with the upper case 1110 removed. Ten battery cells are accommodated in the internal space of the lower case 1101. Two screw holes 1103a and 1103b are formed in the front side wall surface of the lower case 1101 for screwing to the upper case 1110, and screws (not shown) are passed through the screw holes 1103a and 1103b from bottom to top. Although not visible in this figure, two screw holes are also formed in the rear side wall surface of the lower case 1101. A plurality of battery cells (not shown) are fixed by a separator 1145 in a state of being stacked in two rows of five each. The separator 1145 is made of synthetic resin and is formed such that only the left and right sides at both ends of the battery cell are open. Inside the separator 1145, the axes of each battery cell are stacked in parallel, and the adjacent cells are arranged so that the directions are alternately reversed, and the positive and negative terminals of the adjacent battery cells are connected by a metal connection tab (not shown) to connect five battery cells in series. Here, an upper cell unit 1146 (described later in FIG. 41) is formed by five serially connected battery cells installed in the upper stage, and five serially connected battery cells installed in the lower stage form a lower cell unit 1147 (described later in FIG. 41). It should be noted that the upper and lower sides of the cell unit here do not refer to whether the battery cell is in the upper or lower stage in the lower case 1101, but when two cell units are connected in series, the cell unit located on the ground side is called the "lower cell unit", and the cell unit located on the higher voltage side when connected in series is called the "upper cell unit".

[0118] The battery cell used is a rechargeable lithium-ion battery cell (not shown) with a diameter of 18 mm and a length of 65 mm, called the 18650 size. In the sixth embodiment, in order to make it possible to switch the output voltage from the battery pack 1100, forms of series connection voltage (high voltage side output) and parallel connection voltage (low voltage side output) of a plurality of cell units can be selected. Therefore, according to the idea of the sixth embodiment, if the number of cells included in each cell unit is made equal, the number of cell units can be arbitrary. However, the number of cell units is an even number such as two or four. The battery cell to be used is not limited to the 18650 size, and it may be a so-called 21700 size battery cell or other sized battery cells. Also, the shape of the battery cell is not limited to a cylindrical shape, and it may be a rectangular parallelepiped shape, a laminated shape, or other shapes. The type of battery cell is not limited to lithium-ion batteries, and any type of secondary battery such as nickel-metal hydride battery cells, lithium-ion polymer battery cells, nickel-cadmium battery cells, etc. may be used. Two electrodes are provided at both ends in the length direction of the battery cell. Of the two electrodes, one is the positive electrode and the other is the negative electrode, but the position where the electrodes are provided is not limited to only the both ends side, and any electrode arrangement is acceptable as long as cell units can be easily formed within the battery pack.

[0119] Above the separator 1145 that holds the battery cell, a circuit board 1150 is disposed. The circuit board 1150 fixes a plurality of connection terminals (1161, 1162, 1164 to 1168, 1171, 1172, 1177) by soldering and makes an electrical connection between the circuit pattern and the connection terminals. The circuit board 1150 is further mounted with various electronic components (not shown here) such as a battery protection IC, a microcomputer, a PTC thermistor, a resistor, a capacitor, a fuse, and a light-emitting diode. The circuit board 1150 is fixed so as to extend horizontally above the separator 1145 made of a non-conductor such as a synthetic resin. The material of the circuit board 1150 is a printed circuit board in which a pattern wiring is printed by a conductor such as a copper foil on a substrate impregnated with a resin that is insulating with respect to the material, and a single-layer board, a double-sided board, or a multi-layer board can be used. In this embodiment, a double-sided board is used to have an upper surface (the upper surface visible from FIG. 39, which is the front surface) and a lower surface (the back surface) of the circuit board 1150. A plurality of connection terminals (1161, 1162, 1164 to 1168, 1171, 1172, 1177) are arranged slightly forward of the center in the front-rear direction of the circuit board 1150. Here, the plurality of connection terminals are arranged substantially side by side in the horizontal direction.

[0120] As shown in Fig. 38, each connection terminal is as indicated by engraving on the upper surface of the upper case 1110. From the right side to the left side of the circuit board 1150, in order, there are C+ terminals (1161, 1171: positive electrodes for charging), + terminals (1162, 1172: positive electrodes for discharging), T terminal 1164, V terminal 1165, LS terminal 1166, - terminals (1167, 1177: negative electrodes), and LD terminal 1168 arranged side by side. Here, the connection terminals for the power supply line from the battery pack, that is, the power terminals, are composed of two separated terminal components. That is, the C+ terminal (positive electrode for charging) is composed of the upper positive electrode terminal 1161 and the lower positive electrode terminal 1171, and these pairs of positive electrode terminals (1161, 1171) are arranged at positions corresponding to a single slot 1121. The arm set of the upper positive electrode terminal 1161 is arranged above the inner part of the slot 1121, and the arm set of the lower positive electrode terminal 1171 is arranged below the arm set of the upper positive electrode terminal 1161. Similarly, the + terminal (positive electrode for discharging) indicated by engraving on the upper case 1110 is composed of the upper positive electrode terminal 1162 and the lower positive electrode terminal 1172, and these pairs of positive electrode terminals (1162, 1172) are arranged at positions corresponding to a single slot 1122. The arm set of the upper positive electrode terminal 1162 is arranged above the slot 1122 part, and the arm set of the lower positive electrode terminal 1172 is arranged below the arm set of the upper positive electrode terminal 1162. The - terminal (negative electrode) indicated by engraving on the upper case 1110 is composed of the upper negative electrode terminal 1167 and the lower negative electrode terminal 1177, and these pairs of negative electrode terminals (1167, 1177) are arranged at positions corresponding to a single slot 1127. The arm set of the upper negative electrode terminal 1167 is arranged above the slot 1127 part, and the arm set of the lower negative electrode terminal 1177 is arranged below the arm set of the upper negative electrode terminal 1167. The upper positive electrode terminal 1162 and the lower positive electrode terminal 1172 each function as a positive electrode terminal, and as will be described later, they also function as switching terminals for switching the output voltage of the battery pack 1100 to a low voltage and as parallel terminals for connecting a plurality of cell units 1146 and 1147 in parallel with each other. The upper positive electrode terminal 1162 and the lower positive electrode terminal 1172, which are a plurality of parallel terminals, are arranged adjacent to each other and constitute a parallel terminal group.Similarly, the upper negative terminal 1167 and the lower negative terminal 1177 each function as a negative terminal, and as will be described later, also function as switching terminals for switching the output voltage of the battery pack 1100 to a low voltage, and also function as parallel terminals for connecting a plurality of cell units 1146 and 1147 in parallel to each other. The upper negative terminal 1167 and the lower negative terminal 1177, which are a plurality of parallel terminals, are arranged adjacent to each other and constitute a parallel terminal group. Also, as will be described later, the lower positive terminal 1172 and the lower negative terminal 1177 each also function as series terminals for connecting a plurality of cell units 1146 and 1147 in series to each other. Therefore, the upper positive terminal 1162, the lower positive terminal 1172, the upper positive terminal 1162, and the lower positive terminal 1172 function as voltage switching elements for switching the output voltage of the battery pack 1100.

[0121] The connection terminals (1161, 1162, 1164 to 1168) are arranged at positions corresponding to the slots 1121 to 1128 shown in FIG. 38. Therefore, they are arranged such that the fitting portions of the connection terminals open upward and forward from the circuit board 1150. However, the portion between the upper positive terminal 1162 and the T terminal 1164 becomes an empty space that is not used in the battery pack 1100 of this embodiment, similar to the conventional battery pack 1015 (see FIG. 36).

[0122] The charging positive terminal pair (1161, 1171) is configured to be offset forward from the adjacent positive terminal pair (1162, 1172). This is due to space constraints and is to avoid the movement range of a latch mechanism (not shown) immediately behind the positive terminal pair (1161, 1171). Therefore, if there are no space constraints, the positive terminal pair (1161, 1171) is preferably arranged such that its front end position is aligned with the positive terminal pair (1162, 1172) and the negative terminal pair (1167, 1177).

[0123] The positive terminals (1161, 1162, 1171, 1172) and the negative terminals (1167, 1177) are arranged at positions widely separated in the left - right direction, and three signal terminals (T - terminal 1164, V - terminal 1165, LS - terminal 1166) are provided between them. In this embodiment, the voltage - switching element for switching between parallel connection and series connection is realized by the upper - side positive terminal 1162 and the upper - side negative terminal 1167, and the lower - side positive terminal 1172 and the lower - side negative terminal 1177. Also, as parts for signal terminals, those having a total of two sets of arm portions extending in the horizontal direction, one set on the upper left and right and one set on the lower left and right, are used, and their detailed shapes will be described later with reference to FIG. 44. Incidentally, regarding the signal terminals (1164 - 1166, 1168), it is also possible to directly use a signal - terminal part having one arm portion in the vertical direction as conventionally used. However, in this embodiment, in order to make the fitting state with the device - side terminals in the positive terminals (1161, 1162, 1171, 1172) and the negative terminals (1167, 1177) equivalent, signal - terminal parts having two arm portions vertically (described later with reference to FIG. 44) are used on the signal - terminal side as well.

[0124] On the left side of the negative - terminal pair (1167, 1177), a further signal terminal, that is, the LD - terminal 1168 is provided. The LD - terminal 1168 is also formed to have two sets of upper - side and lower - side arm portions. However, the LD - terminal 1168 is different in size from the other signal terminals (T - terminal 1164, V - terminal 1165, LS - terminal 1166). This is due to space constraints. Since a latch mechanism (not shown) reaches immediately behind the LD - terminal 1168, it is made smaller than the other signal terminals to avoid it. All the signal terminals (1164 - 1166, 1168) penetrate the formed mounting holes 1151 of the circuit board 1150 from the front surface to the back surface with their leg portions, and are fixed by soldering on the back - surface side. In this embodiment, the fixing method of the three signal terminals (1164 - 1166) also has features, and the details will be described later with reference to FIGS. 44 and 45. As described above, after an electronic element (not shown) is mounted on the circuit board 1150 and a plurality of connection terminals are fixed by soldering, the circuit board 1150 is fixed to the separator 1145 by screwing or adhesion or the like.

[0125] Four LEDs (not shown) are provided near the rear side of the circuit board 1150, and above the LEDs, prisms 1191 to 1194 in the shape of vertically elongated rectangular parallelepipeds are provided. The prisms 1191 to 1194 are arranged so that the bottom surfaces face the lighting surfaces of the LEDs (light-emitting diodes, not shown) that irradiate upward, and the upper surfaces cut obliquely are provided so as to be exposed to the outside through slits (not shown) formed in the upper case 1110. The prisms 1191 to 1194 are provided to diffuse light and irradiate the outside of the upper case 1110. The four LEDs not shown are used to display the remaining amount of the battery pack 1100. When the operator presses the switch 1190, the number of LEDs corresponding to the voltage of the battery cell is lit for a certain period of time. An operation lever (not shown) for operating the switch 1190 is provided on the outer surface portion of the upper case 1110 that can be operated by the operator. The lower case 1101 has a substantially rectangular parallelepiped shape with an open upper surface, and is composed of a bottom surface, a front wall 1101a, a rear wall 1101b, a right side wall 1101c, and a left side wall 1101d that extend in the vertical direction with respect to the bottom surface. A slit 1104 is provided substantially at the center of the front wall 1101a. The slit 1104 is used as an outlet for discharging the cooling air sent from the charging device side into the internal space of the battery pack 1100 when charging is performed by the charging device.

[0126] Next, the shapes of the components (1200, 1220) used for the power terminals will be described with reference to FIG. 40. FIG. 40(1) is a perspective view showing the individual components of the upper terminal component 1200 and the lower terminal component 1220. The upper terminal component 1200 is a common component used for the upper positive terminals 1161, 1162, and the upper negative terminal 1167, and the lower terminal component 1220 is a common component used for the lower positive terminals 1171, 1172, and the lower negative terminal 1177. The upper terminal component 1200 and the lower terminal component 1220 are formed by cutting out a flat plate made of conductive metal by pressing and then bending it into a U shape. The upper terminal component 1200 is bent so that the surface that becomes the bottom of the U shape, that is, the bridge portion 1202, faces upward, and in the lower terminal component 1220, the bridge portion 1222 is bent so that it faces the rear side. In this way, the bridge portions 1202 and 1222 formed by bending into a U shape are arranged so as to intersect at substantially a right angle because the area of the side wall surface of the front bridge portion 1222 cannot be sufficiently secured in the front-rear direction, and if the bridge portion is arranged on the upper side, the size of the bridge portion will become small. In the lower terminal component 1220 of this embodiment, since the bridge portion 1222 is in the vertical plane direction, the length in the front-rear direction required for the arrangement can be shortened, and the size of the bridge portion, particularly the length in the vertical direction, can be sufficiently secured, so the rigidity of the lower terminal component 1220 could be increased. On the other hand, in the upper terminal component 1200, long arm portions 1205, 1206 that straddle the lower terminal component 1220 can be formed, and the bridge portion 1202 is a surface that extends in the same direction as the front-rear direction in which the arm portions 1205, 1206 extend, so the mounting rigidity of the arm portions 1205, 1206 could be increased.

[0127] The upper terminal component 1200 has a right side surface 1203 and a left side surface 1204 that are formed by being bent into a U shape and are parallel to each other, and a bridge portion 1202 that connects them and serves as the upper surface. On the front sides of the right side surface 1203 and the left side surface 1204, arm portions 1205 and 1206 for sandwiching the device-side terminals from both the left and right sides inward are respectively provided. Among the front side edges of the left side surface 1204, it extends linearly in the vertical direction from the lower side to a position close to the upper end, and is formed to extend forward by drawing a curve with a large radius of curvature from near the arrow 1204d close to the upper end. The shape of the right side surface 1203 is formed symmetrically with respect to the left side surface 1204. The arm portion 1205 is arranged to extend forward from the upper front side of the right side surface 1203, and the arm portion 1206 is arranged to extend forward from the upper front side of the left side surface 1204. Thus, the arm portions 1205 and 1206 are formed to extend forward from the upper portion of the front side edge of the base portion 1201, that is, in a direction parallel to the mounting direction of the battery pack 1100. The arm portions 1205 and 1206 are pressed so as to face each other in the left-right direction and be close to each other up to the minimum interval portion, that is, the position where the fitting portions that fit with the device connection terminals are almost in contact, thereby giving them spring properties. Here, the pressing process refers to plastic processing performed using a press machine. By pressing a material such as sheet metal against a mold with a high pressure to perform shearing processes such as cutting, punching, and drilling, and further performing bending and drawing processes as necessary, it is sheared and formed into the required shape. In this embodiment, the upper terminal component 1200 and the lower terminal component 1220 are formed of, for example, flat plates with a thickness of about 0.5 to 0.8 mm. Thereby, the upper positive electrodes 1161, 1162, 1171, 1172 and the upper negative electrodes 1167, 1177 have high mechanical strength, and the fitting pressure when fitting with the device-side terminals becomes high. Incidentally, heat treatment, plating treatment, etc. may be performed after the pressing process.

[0128] The lower terminal component 1220 is also manufactured in the same manner, and has a base portion 1221 composed of a right side surface 1223 and a left side surface 1224 that are bent in a U shape and formed to be parallel, and a bridge portion 1222 that connects them. Arms 1225 and 1226 are formed on the front side near the elongated upper portions of the right side surface 1223 and the left side surface 1224. The arms 1225 and 1226 are shaped to sandwich the device-side terminals from both the left and right sides inward. The distance S between the upper end positions of the upper arm sets (1205, 1206) and the lower end positions of the lower arm sets (1225, 1226) is configured to be approximately equal to the width of the power terminals provided in a conventional 18V battery pack. On the other hand, the upper arm sets (1205, 1206) and the lower arm sets (1225, 1226) are arranged so as to be separated from each other by a predetermined distance S1 in the vertical direction. A notch portion 1231 that is largely cut out from the front side is formed below the lower arm sets (1225, 1226). The rear side of the lower terminal component 1220 is arranged and fixed in the front-rear direction so as not to contact each other with a predetermined gap 1211 from the right side surface 1203 and the left side surface 1204 of the upper terminal component 1200. Thus, the plurality of power terminals (1161, 1162, 1167, 1171, 1172, 1177) are arranged side by side in the left-right direction at a position above the separator 1145, and the terminal pairs that serve as voltage switching elements are arranged at a position approximately the same height as the height at which the conventional power terminals were arranged in the vertical direction. Also, a part of the lower positive terminal 1172 and a part of the lower negative terminal 1177 that function as series terminals are at the same height as a part of the upper positive terminal 1162 that functions as a positive terminal and a part of the upper negative terminal 1167 that functions as a negative terminal in the vertical direction. Therefore, the series terminals are arranged at a position approximately the same height as the positive terminal and the negative terminal in the vertical direction, and the vertical size of the battery pack is configured to be compact.

[0129] Figure 40(2) is a perspective view of the upper terminal component 1200 alone. Here, hatching is applied to the region of the bridge portion 1202 and the portions of the leg portions 1207 and 1208 to clearly show the scope. The base portion 1201 as referred to in this specification is the portion that is exposed upward from the surface of the circuit board 1150 to which it is attached, excluding the arm portions 1205 and 1206. The base portion 1201 of the upper terminal component 1200 is composed of a right side surface 1203, a left side surface 1204, and a bridge portion 1202. Below the lower side of the base portion 1201, leg portions 1207 and 1208 are connected. The leg portions 1207 and 1208 are inserted into the mounting holes (through holes) 1151 of the circuit board 1150, and the leg portions 1207 and 1208 protrude from the mounting surface (front surface) of the circuit board 1150 to the surface on the opposite side of the mounting surface (back surface), and the leg portions 1207 and 1208 are soldered to the circuit board 1150 on the back surface. Also, by soldering, the arm portions 1205 and 1206 are electrically connected to battery cells, electronic components, etc. mounted on the circuit board 1150. Here, the height H1 of the leg portions 1207 and 1208 is formed to be greater than the thickness of the circuit board 1150 and less than twice that thickness. Further, a convex portion 1204b that protrudes rearward is formed at the lower portion of the rear side of the left side surface 1204. Although not visible in Figure 40, a similar convex portion is also formed at the lower portion of the rear side of the right side surface 1203. At the front side of the lower portions of the right side surface 1203 and the left side surface 1204, portions that extend convexly in the horizontal direction are formed, and bent portions 1203a and 1204a are formed by bending the convex portions inward. Cutout portions 1203c, 1204c, 1207a, and 1208a are formed above and below the bent portions of the bent portions 1203a and 1204a to facilitate the bending process. The bent portions 1203a and 1204a and the convex portions 1203b and 1204b are formed to contact the upper surface near the mounting holes of the circuit board 1150 to position the upper terminal component 1200 in the vertical direction.

[0130] The base portion 1201 is formed in a substantially L-shape that is inverted in a side view. In the rear portions of the arm portions 1205 and 1206, flat portions 1205a and 1206a are formed where the right side surface 1203 and the left side surface 1204 extend in the same plane from near the rear connection portions toward the front. The lateral interval between the flat portions 1205a and 1206a is constant and parallel. In front of the flat portions 1205a and 1206a, bending portions 1205b and 1206b that are bent inward in the lateral direction are formed. In front of the bending portions 1205b and 1206b, flat portions 1205c and 1206c are formed again. The opposing flat portions 1205c and 1206c have a tapered shape where the rear interval is wide and gradually narrows toward the front, and each is a surface extending in the vertical direction. The tip portions of the flat portions 1205c and 1206c are formed with fitting portions 1205d and 1206d that are bent outward with a relatively large radius of curvature R1. When the inner curved surface portions of the fitting portions 1205d and 1206d contact the terminals of the power tool main bodies 1001 and 1030, the upper terminal component 1200 is electrically connected to the connection terminals on the power tool main body 1001 and 1030 sides. The inner side of the fitting portions 1205d and 1206d is shaped to have a slight gap 1209 when the battery pack 1100 is removed from the power tool main bodies 1001 and 1030. The front sides of the fitting portions 1205d and 1206d are connected to guide portions 1205e and 1206e that are formed such that the interval rapidly widens toward the front, and guide the terminals on the power tool main body 1001 and 1030 sides. The inner surfaces of the guide portions 1205e and 1206e are planar here, but may also be curved. From the bending portion 1205b to the guide portion 1205e, and from the bending portion 1206b to the guide portion 1206e, they are formed to have a constant height in the vertical direction. On the other hand, the flat portions 1205a and 1206a are formed with downward notch portions 1205f and 1206f such that the height decreases toward the rear. The notch portions 1205f and 1206f are formed for manufacturing reasons to facilitate the bending of the arm portions 1205 and 1206 during press working, and to adjust the clamping load (or fitting pressure) in a set of the fitting portions 1205d and 1206d. By forming as described above, an upper terminal component 1200 with excellent durability and easy to use can be realized.Further, it is preferable that the height direction of the fitting portions 1205d and 1206d among the wrist portions 1205 and 1206 be made as large as possible, but the vertical heights of the bending portions 1205b and 1206b, the flat portions 1205c and 1206c, and the guide portions 1205e and 1206e do not necessarily have to be constant and may be formed in a shape that changes as it goes in the front-rear direction.

[0131] Figure 40(3) is a perspective view of the lower terminal component 1220 alone. Here too, the region of the bridge portion 1222 and the portions of the leg portions 1227 and 1228 are hatched to clearly show the range. As can be seen from this figure, the bending direction of the lower terminal component 1220 is different from that of the upper terminal component 1200 in a U-shaped bend. Here, the base portion 1221 is in a substantially L-shaped upright position in side view, and the arm portions 1225 and 1226 are connected in front of the upper front edges of the right side surface 1223 and the left side surface 1224. Near the connection portions of the arm portions 1225 and 1226 with the base portion 1221, flat portions 1225a and 1226a are formed on the same plane as the right side surface 1223 and the left side surface, and the opposing surfaces are parallel. In front of the flat portions 1225a and 1226a, bending portions 1225b and 1226b that are bent inward in the left-right direction are formed. Flat portions 1225c and 1226c are formed again on the front side of the bending portions 1225b and 1226b. The opposing flat portions 1225c and 1226c have a shape of a tapered end that is wider at the rear and gradually narrows as it goes forward. Fitting portions 1225d and 1226d bent with a relatively large radius of curvature are formed at the tip portions of the flat portions 1225c and 1226c. When the inner curved surfaces of the fitting portions 1225d and 1226d come into contact with the terminals of the power tool main bodies 1001 and 1030, they will be electrically conductive. The inside of the fitting portions 1225d and 1226d is shaped to have a slight gap when the battery pack 1100 is removed from the power tool main bodies 1001 and 1030. The front side of the fitting portions 1225d and 1226d is formed so that the interval rapidly widens as it goes forward, and guide portions 1225e and 1226e for guiding the terminals on the power tool main body 1001 and 1030 sides are formed. The inner surfaces of the guide portions 1225e and 1226e may be flat or curved. From the flat portion 1225a to the guide portion 1225e, and from the flat portion 1226a to the guide portion 1226e, they are formed so that the height in the vertical direction is constant. However, similar to the arm portions 1205 and 1206 of the upper terminal component 1200, it may be formed so that the height in the vertical direction changes except for the fitting portions 1225d and 1226d. By forming as described above, in this embodiment, a lower terminal component 1220 with excellent durability and easy to use can be realized.

[0132] On the lower sides of the arms 1225 and 1226 of the lower terminal component 1220, a notch portion 1231 (see Fig. 40(1)), which is cut out in a U shape in a side view, is formed from the front side toward the rear side. The notch portion 1231 is formed because a substrate cover 1180 (to be described later in Fig. 46), which partitions the upper terminal component 1200 and the lower terminal component 1220, is provided at this portion. Legs 1227 and 1228 are connected to the lower side of the base body portion 1221. The legs 1227 and 1228 are inserted into the mounting holes of the circuit board 1150, and the legs 1227 and 1228 are projected from the mounting surface (front surface) of the circuit board 1150 to the opposite surface (back surface), and the projecting portions are soldered. Also, an electrical connection state from the arms 1225 and 1226 to battery cells, electronic elements, etc. mounted on the circuit board 1150 is established by soldering. Here, the set of the legs 1227 and 1228 is independently wired in a state where it does not short-circuit with the set of the legs 1207 and 1208 of the upper terminal component 1200. The dimensions and shapes of the legs 1227 and 1228 are substantially the same as those of the legs 1207 and 1208, and bent portions 1223a and 1224a are formed on the front side. Cutout portions 1223c, 1224c, 1227a, and 1228a are formed above and below the bent portions of the bent portions 1223a and 1224a, but the cutout portions are not necessarily required because they are for improving the accuracy of the bending process during press working.

[0133] Next, using FIG. 41, the shape of the terminal portions 1020 on the side of the power tool main bodies 1001 and 1030 and the connection state with the connection terminals of the battery pack 1100 when the battery pack 1100 is attached to the power tool main bodies 1001 and 1030 will be described. Here, among the connection terminals of the battery pack 1100, the positive electrodes for discharging (upper positive electrode terminal 1162 and lower positive electrode terminal 1172) and the negative electrode terminals (upper negative electrode terminal 1167 and lower negative electrode terminal 1177) are illustrated. Further, LD terminals 1028 and 1058 are provided at the terminal portions 1020 and 1050 of the power tool main bodies 1001 and 1030, but are not illustrated here. FIG. 41(1) is a diagram showing a state where the battery pack 1100 is attached to the 36V power tool main body 1030. As described above, 10 battery cells are housed inside the battery pack 1100, 5 of which constitute the upper cell unit 1146, and the remaining 5 constitute the lower cell unit 1147. Here, the terminal portion has a smaller terminal portion 1052a and 1057a of the positive electrode input terminal 1052 and the negative electrode input terminal 1057 compared to the terminal portion 1020 of the conventional power tool main body 1001. That is, the width in the vertical direction is formed to be small so as to contact only the upper positive electrode terminal 1162 and the upper negative electrode terminal 1167 arranged on the upper side. The positive electrode side output terminal of the upper cell unit 1146 is connected to the upper positive electrode terminal 1162, and the negative electrode side output terminal is connected to the lower negative electrode terminal 1177. On the other hand, the positive electrode side output terminal of the lower cell unit 1147 is connected to the lower positive electrode terminal 1172, and the negative electrode side output terminal is connected to the upper negative electrode terminal 1167. That is, two sets of positive and negative electrode terminals are provided independently, and one set of terminals (upper positive electrode terminal 1162 and lower negative electrode terminal 1177) that cross in the left-right direction and vertically is connected to the upper cell unit 1146, and the other set of terminals (lower positive electrode terminal 1172 and upper negative electrode terminal 1167) is connected to the lower cell unit 1147. Since the upper positive electrode terminal 1161 and the lower positive electrode terminal 1172 are not electrically connected, in a state where the battery pack 1100 is not attached to the electric device main body (a state where the battery pack 1100 is removed), they are in an electrically independent state.Similarly, since the upper negative terminal 1167 and the lower negative terminal 1177 are not electrically connected inside the battery pack 1100, they are in an electrically independent state when the battery pack 1100 is not attached to the electric device main body (the state where the battery pack 1100 is removed).

[0134] As shown in Fig. 41(1), a power receiving positive input terminal 1052 and a negative input terminal 1057 are provided at the terminal portion of the electric power tool main body 1030 rated at 36V. At the time of mounting, the positive input terminal 1052 is in a positional relationship such that it fits only with the upper positive terminal 1162, and the negative input terminal 1057 is in a positional relationship such that it fits only with the upper negative terminal 1167. On the other hand, a short bar 1059 is further provided at the terminal portion of the electric power tool main body 1030 to connect the lower positive terminal 1172 and the lower negative terminal 1177 in a short circuit manner. The short bar 1059 is a short-circuiting element or a conducting terminal made of a metal conductive member, functions as a switching element for switching the output voltage from the battery pack 1100 to a high voltage, and further functions as a connecting element for high voltage for connecting a plurality of cell units 1146 and 1147 in series with each other. One end side of the metal member bent in a U-shape of the short bar 1059 becomes a terminal portion 1059b that fits with the lower positive terminal 1172, and the other end side becomes a terminal portion 1059c that fits with the lower negative terminal 1177. The terminal portion 1059b and the terminal portion 1059c are connected by a connecting portion 1059a. The short bar 1059 is fixed by being cast into a synthetic resin base 1051 (described later in Fig. 42) together with other device-side terminals such as the positive input terminal 1052 and the negative input terminal 1057. Since the short bar 1059 is used only for short-circuiting the lower positive terminal 1172 and the lower negative terminal 1177, there is no need to wire it to the control circuit or the like of the electric power tool main body.

[0135] The positive input terminal 1052 is formed by a terminal portion 1052a that is flat and shaped to fit with the upper positive terminal 1162, a wiring portion 1052c for soldering a lead wire for connecting to the circuit board side of the power tool main body 1030, and a connecting portion 1052b that connects between the terminal portion 1052a and the wiring portion 1052c and is cast into the synthetic resin base 1051. Here, the position of the wiring portion 1052c is arranged to be shifted inward compared to the left-right direction position of the terminal portion 1052a. This is to adjust the interval of the wiring portion 1052c and to ensure that the connecting portion 1052b is stably held in the base 1051 by casting. Further, the left and right front corners of the terminal portion 1052a are chamfered diagonally so that the terminal portion 1052a can easily enter between the arm portions 1162a and 1162b. The negative input terminal 1057 can be made of the same common parts as the positive input terminal 1052. By arranging it in a state rotated 180 degrees around the vertical axis, it can be used as both the negative input terminal 1057 and the positive input terminal 1052. Therefore, the negative input terminal 1057 is also formed by a terminal portion 1057a, a wiring portion 1057c, and a connecting portion 1057b that connects them. The front corner of the terminal portion 1057a (the rear corner when this component is used as the positive input terminal 1052) is also chamfered diagonally so that the terminal portion 1057a can easily enter between the arm portions 1167a and 1167b.

[0136] In FIG. 41(1), when mounting the battery pack 1100, when the battery pack 1100 is relatively moved along the insertion direction with respect to the power tool main body 1030, the positive input terminal 1052 and the terminal portion 1059b are inserted to the inside through the same slot 1122 (first slot, see FIG. 38), and are respectively fitted to the upper positive terminal 1162 and the lower positive terminal 1172. At this time, the positive input terminal 1052 is press-fitted between the arm portions 1162a and 1162b of the upper positive terminal 1162 so as to expand the fitting portions of the upper positive terminal 1162. Further, the negative input terminal 1057 and the terminal portion 1059c are inserted to the inside through the same slot 1127 (second slot, see FIG. 38), and are respectively fitted to the upper negative terminal 1167 and the lower negative terminal 1177. At this time, the negative input terminal 1057 is press-fitted between the arm portions 1167a and 1167b of the upper negative terminal 1167 so as to expand the fitting portions of the upper negative terminal 1167. Furthermore, the terminal portions 1059b and 1059c of the short bar 1059 are press-fitted so as to expand between the arm portions 1172a and 1172b, and between the arm portions 1177a and 1177b of the lower positive terminal 1172 and the lower negative terminal 1177. The front corner portions of the terminal portions 1052a, 1054a to 1058a, 1059b, and 1059c are chamfered obliquely like the arrows 1052d, 1054d to 1059d, 1059e so as to be smoothly inserted between the arm portions of the connection terminals on the battery pack 1100 side. In the state where the battery pack 1100 is connected to the power tool main body 1030 in this way, the positive terminal (1162) and the positive input terminal 1052 are connected via the first slot (slot 1122), the negative terminal (1167) and the negative input terminal (1057) are connected via the second slot (slot 1127), and these voltage switching elements and switching elements are engaged via the first and second slots. Also, in the state where the battery pack is connected to the electric device main body, the voltage switching elements such as the positive terminal, the positive input terminal, the negative terminal, and the negative input terminal, and the switching element by the short bar 1059 are arranged at positions having substantially the same height in the vertical direction.

[0137] The plate thicknesses of the terminal portions 1052a, 1057a, 1059b, and 1059c are greater than the initial gaps (the gaps when the battery pack 1100 is not mounted) of the fitting portions of the respective arm portions. Therefore, a predetermined fitting pressure acts on the fitting points between each of the terminal portions 1052a, 1057a, 1059b, and 1059c and the upper positive terminal 1162, the lower positive terminal 1172, the upper negative terminal 1167, and the lower negative terminal 1177. As a result of such connection, the device-side terminals (the terminal portions 1052a, 1057a, 1059b, and 1059c) of the power tool main body 1030 and the power terminals of the battery pack (the upper positive terminal 1162, the lower positive terminal 1172, the upper negative terminal 1167, and the lower negative terminal 1177) are in good contact in a state where the electrical contact resistance is reduced. In this way, the power tool main body 1030 has a third terminal (1052a) that is inserted into a single slot (1122) and connected only to the first terminal (1162) among the first and second terminals (1162, 1172), and a fourth terminal (1059b) that is inserted into the single slot (1122) and connected only to the second terminal (1172). When the battery pack 1100 is connected to the power tool main body 1030, within the single slot 1121, the first and third terminals (1162 and 1052a) are connected to each other and both have a first potential, and the second and fourth terminals (1172 and 1059b) are connected to each other and both have a second potential different from the first potential. Since the connection state is the same on the negative terminal pair (1167, 1177) side as well, by realizing the connection form of FIG. 41(1), the output of the series connection of the upper cell unit 1146 and the lower cell unit 1147, that is, the rated 36V, is output from the battery pack 1100.

[0138] On the one hand, when the battery pack 1100 is attached to the conventional electric tool body 1001 for 18V, the connection relationship is as shown in Fig. 41(2). When the battery pack 1100 is attached to the electric tool body 1001, the positive input terminal 1022 is press-fitted so as to expand both the open end portions of the upper positive terminal 1162 and the lower positive terminal 1172, and a part of the upper region of the positive input terminal 1022 comes into contact with the upper positive terminal 1162, and a part of the lower region comes into contact with the lower positive terminal 1172. In this way, the positive input terminal 1022 is connected so as to straddle the upper positive terminal 1162 and the lower positive terminal 1172, and fits simultaneously with the arm portions 1162a and 1162b and also fits simultaneously with the arm portions 1172a and 1172b. Similarly, the negative input terminal 1027 is press-fitted so as to expand both the open end portions of the upper negative terminal 1167 and the lower negative terminal 1177, and a part of the upper region of the negative input terminal 1027 comes into contact with the upper negative terminal 1167, and a part of the lower region comes into contact with the lower negative terminal 1177. In this way, the negative input terminal 1027 is connected so as to straddle the upper negative terminal 1167 and the lower negative terminal 1177, and fits simultaneously with the arm portions 1167a and 1167b and also fits simultaneously with the arm portions 1177a and 1177b. As a result, the upper positive terminal 1162 and the lower positive terminal 1172 are in a short-circuit state, and the upper negative terminal 1167 and the lower negative terminal 1177 are in a short-circuit state, and the output of the parallel connection of the upper cell unit 1146 and the lower cell unit 1147, that is, the rated 18V, is output to the electric tool body 1001. Therefore, the positive input terminal 1022 and the negative input terminal 1027 function as switching elements for switching the output voltage of the battery pack 1100 to a low voltage, and also function as connection elements for low voltage for connecting a plurality of cell units 1146 and 1147 in parallel with each other. The positive input terminal 1022 and the negative input terminal 1027 serving as the connection elements are made of a metal plate having a certain thickness. Therefore, it is important that the fitting pressure by the arm portions of the upper positive terminal 1162 and the upper negative terminal 1167 is equal to the fitting pressure by the arm portions of the lower positive terminal 1172 and the lower negative terminal 1177.Also, in order to make these fitting pressures constant, the thicknesses of the positive input terminal 1052, the negative input terminal 1057, and the terminal portions 1059b and 1059c of the short bar 1059 of the 36V power tool body 1030 shown in Fig. 41(1) are made the same as the thicknesses of the positive input terminal 1022 and the negative input terminal 1027 of the conventional 18V power tool body 1001.

[0139] As described above, the battery pack 1100 of the present embodiment can be attached to the 18V power tool body 1001 or the 36V power tool body 1030, and the output of the battery pack 1100 is automatically switched. Therefore, a user-friendly battery pack 1100 compatible with multiple voltages can be realized. This voltage switching is not performed on the battery pack 1100 side, but is automatically performed according to the shape of the terminal portions on the power tool body 1001 and 1030 sides, so there is no possibility of voltage setting errors. In addition, since there is no need to provide a dedicated voltage switching mechanism such as a mechanical switch on the battery pack 1100 side, the structure is simple, the risk of failure is low, and a long-life battery pack can be realized. The short bar 1059 that short-circuits the lower positive terminal 1172 and the lower negative terminal 1177 can be mounted within the same space as the existing terminal portion 1020 of the 18V battery pack. Therefore, a voltage-switchable battery pack with a size compatible with the conventional one can be realized. Furthermore, when charging is performed using an external charging device, charging can be performed by the connection method shown in Fig. 41(2), so there is no need to prepare a charging device capable of performing both high-voltage / low-voltage charging. When the battery pack 1100 is charged with an external charging device (not shown), it can be charged with the same charging device as the conventional 18V battery pack. In that case, the terminals of the charging device have the same shape as in Fig. 41(2), but instead of the positive terminals (1162, 1172) for discharging, the positive terminals for charging (the upper positive terminal 1161 and the lower positive terminal 1171) are connected to the positive terminal of the charging device (not shown). The connection status at that time is also substantially the same as the connection relationship shown in Fig. 41(2). In this way, since charging is performed using an 18V charging device with the upper cell unit 1146 and the lower cell unit 1147 connected in parallel, there is no need to prepare a new charging device when charging the battery pack 1100 of the present embodiment.

[0140] Figure 42(1) is a perspective view of the terminal portion 1050 of the power tool body 1030 of the sixth embodiment. In addition to the positive input terminal 1052, the negative input terminal 1057, and the short bar 1059 shown in Figure 41(1), the terminal portion 1050 is manufactured by casting four metal connection terminals 1054 to 1056, 1058 into a synthetic resin base 1051. The shapes of the connection terminals 1054 to 1056 are formed by making the connecting portions 1052b, 1057b of the positive input terminal 1052 and the negative input terminal 1057 in Figure 41(1) linear. Terminal portions 1054a to 1056a that are fitted to the connection terminals on the battery pack 1100 side are formed on one side, and wiring portions 1054c to 1056c in which holes are formed on the other side and lead wires are soldered are formed. Connection portions 1054b to 1056b that connect between the terminal portions and the wiring portions and are cast into the synthetic resin are formed. The base 1051 holds the terminal portions 1052a, 1054a to 1058a firmly by casting the entire upper side portion and the entire rear side portion of the terminal portions 1052a, 1054a to 1058a. Also, for the terminal portions 1054a to 1056a, 1058a, a part of the rear of the lower side portion is cast. The short bar 1059 whose shape was shown in Figure 41(1) has a connecting portion 1059a (see Figure 41) extending in the left-right direction entirely cast into the base 1051, and the front portions of the terminal portions 1059b and 1059c are exposed forward from the base 1051. Also, by casting the lower part on the rear side of the portions of the terminal portions 1059b, 1059c that are exposed outside into the base 1051, the terminal portions 1059b, 1059c are firmly held so as not to move in the left-right direction. In this way, a plurality of plate-shaped device-side terminals are arranged side by side in the terminal portion 1050. Here, the terminal portion 1052a and the terminal portion 1059b are arranged so as to have a constant gap 1053a in the vertical direction. Similarly, the terminal portion 1057a and the terminal portion 1059c are arranged so as to have a constant gap 1053b in the vertical direction.

[0141] Figure 42(2) is a diagram showing the connection status between the terminal unit 1050 and the power terminals (1162, 1172, 1167, 1177) of the battery pack 1100. The upper positive terminal 1162 has two arm portions 1162a, 1162b (corresponding to the arm portions 1205, 1206 in Fig. 40(1)), and the lower positive terminal 1172 of the positive electrode has two arm portions 1172a, 1172b (corresponding to the arm portions 1225, 1226 in Fig. 40(1)). The arm portions 1162a, 1162b of the upper positive terminal 1162 are connected so as to sandwich the plate-shaped terminal portion 1052a from left and right. At the time of this joining, the arm portions 1162a, 1162b are bent so as to separate in the left-right direction, and a predetermined clamping load (fitting pressure) is applied to the terminal portion 1052a by the restoring force of the spring action. As a result, the arm portions 1162a, 1162b and the terminal portion 1052a come into good surface contact or line contact, so that a good conductivity with extremely low contact resistance can be realized. Similarly, the arm portions 1167a, 1167b of the upper negative terminal 1167 are fitted so as to sandwich the plate-shaped terminal portion 1057a from left and right.

[0142] The arm portions 1172a, 1172b of the lower positive terminal 1172 are fitted so as to sandwich the plate-shaped terminal portion 1059b from left and right. At the time of this fitting, the arm portions 1172a, 1172b are bent so as to separate in the left-right direction, and a predetermined clamping load (fitting pressure) is applied to the terminal portion 1059b by the restoring force of the spring action. As a result, the arm portions 1172a, 1172b and the terminal portion 1059b come into good surface contact or line contact, so that a good conductivity with no contact resistance can be realized. Similarly, the arm portions 1177a, 1177b of the lower negative terminal 1177 are fitted so as to sandwich the plate-shaped terminal portion 1059c from left and right.

[0143] What is important in this embodiment is to maintain a non-contact state between the connection portion of the terminal portion 1052a and the upper positive electrode terminal 1162 and between the connection portion of the terminal portion 1059b and the lower positive electrode terminal 1172, thereby maintaining an electrical insulation state. Also, it is to maintain a non-contact state between the connection portion of the terminal portion 1057a and the upper negative electrode terminal 1167 and between the connection portion of the terminal portion 1059c and the lower negative electrode terminal 1177, thereby maintaining an electrical insulation state. With such a configuration, even when the battery pack 1100 vibrates at a resonance frequency different from that of the power tool main body 1030 due to various vibrations and impacts during the use of the power tool, it is possible to prevent a short circuit from occurring between the upper positive electrode terminal 1162 and the lower positive electrode terminal 1172, and it is possible to prevent a short circuit from occurring between the upper negative electrode terminal 1167 and the lower negative electrode terminal 1177. Incidentally, in FIG. 42(2), the illustration of the connection terminals on the battery pack side that are fitted to the terminal portions 1054a to 1056a and 1058a is omitted. However, when the power terminals on the positive electrode side (the upper positive electrode terminal 1162 and the lower positive electrode terminal 1172) and the power terminals on the negative electrode side (the upper negative electrode terminal 1167 and the lower negative electrode terminal 1177) are connected, the signal terminals (the T terminal 1164, V terminal 1165, LS terminal 1166, LD terminal 1168 shown in FIG. 39) are also fitted to the terminal portions 1054a to 1056a and 1058a in the same manner.

[0144] Fig. 43(1) is a perspective view of the terminal portion 1020 of the conventional power tool body 1001, and (2) is a diagram showing the connection state with the power terminals of the battery pack 1100. The terminal portion 1020 is manufactured by casting six metal terminals 1022, 1024 to 1028 into a synthetic resin base 1021. As shown in Fig. 41, which shows a part of the terminals 1022 and 1027 before casting, the shapes of the terminals 1022, 1024 to 1028 have terminal portions 1022a, 1024a to 1028a that are fitted to the connection terminals on the battery pack 1100 side formed on one side, and holes are formed on the other side to form a wiring portion for soldering the lead wire. A connection portion that connects between the terminal portion and the wiring portion and is cast into the synthetic resin of the base 1021 is formed. The base 1021 holds the terminal portions 1022a, 1024a to 1028a firmly by casting the entire upper side portion, the entire rear side portion, and a part of the rear of the lower side portion of the terminal portions 1022a, 1024a to 1028a. The front corner portions of the terminal portions 1022a, 1024a to 1028a are chamfered obliquely like the arrows 1022d, 1024d to 1028d so that they can be smoothly inserted between the arms of the connection terminals on the battery pack 1100 side. The shape of the terminal portion 1020 has a groove portion 1021b extending in the left-right direction formed on the front side of the base 1021, and a similar groove portion 1021b extending in the left-right direction is also formed on the rear side. These groove portions 1021b and 1021c are clamped at the opening portion of the housing in the terminal portion 1020.

[0145] FIG. 43(2) is a diagram showing the connection state between the terminal unit 1020 and the power terminals (1162, 1172, 1167, 1177) of the battery pack 1100. Here, the illustration of the signal terminals (T terminal 1164, V terminal 1165, LS terminal 1166, LD terminal 1168) on the battery pack 1100 side is omitted. The arms 1162a and 1162b of the upper positive terminal 1162 are fitted so as to sandwich the upper region of the plate-shaped terminal portion 1022a from the left and right. At the time of this fitting, the arms 1162a and 1162b are bent so as to separate in the left-right direction, and a predetermined clamping load (fitting pressure) is applied to the terminal portion 1022a by the restoring force of the spring action. Also, the arms 1162a and 1162b of the lower positive terminal 1172 are fitted so as to sandwich the lower part of the plate-shaped terminal portion 1022a from the left and right. The arms of the upper negative terminal 1167 and the lower negative terminal 1177 of the power terminal are in the same fitting state. In this way, four arms 1162a, 1162b, 1172a, and 1172b come into contact with one terminal portion 1022a. Similarly, on the negative electrode side, the arms 1167a and 1167b of the upper negative terminal 1167 are fitted so as to sandwich the upper region of the plate-shaped terminal portion 1027a from the left and right, and the arms 1177a and 1177b of the lower negative terminal 1177 are fitted so as to sandwich the lower part of the terminal portion 1027a from the left and right. In this way, four arms 1162a, 1162b, 1172a, and 1172b come into contact with one terminal portion 1022a, and similarly, four arms 1167a, 1167b, 1177a, and 1177b come into contact with the terminal portion 1027a, so that they can make good surface contact or line contact, eliminating the contact resistance and realizing good conductivity.

[0146] Next, the shape of the components used for the three terminals (1164 to 1166), that is, the signal terminal component 1240, will be described with reference to FIG. 44. The signal terminal component 1240 is manufactured by pressing a single metal plate. From a base portion 1241 formed by bending a thin metal plate such that a bridge portion 1242 serving as a U-shaped bottom portion becomes the rear vertical surface, an arm set (arm base portions 1245, 1246) extends forward. The arm base portion 1245 is formed to separate into upper and lower arm sets (arms 1251, 1253), and the arm base portion 1246 is formed to separate into upper and lower arm sets (1252, 1254) by a notch groove 1244b extending in the horizontal direction. The metal plate used for pressing may be a flat plate with a thickness of 0.3 mm, which may be thinner than the plate thickness of 0.5 mm of the upper terminal component 1200 and the lower terminal component 1220 used for the power terminals. The upper and lower arm sets are formed in the same shape, and have the same length in the front-rear direction, width in the up-down direction, plate thickness, etc. Fitting portions (1251d, 1253d, etc.) are formed in the upper arm set (arms 1251 and 1252) and the lower arm set (arms 1253 and 1254), respectively. The curved shapes for the fitting portions are also the same up and down, and the left and right arms have a plane-symmetric shape. On the other hand, the attachment positions of the legs 1249 and 1250 are arranged so as to be largely shifted in the front-rear direction. The shape of the lower side portion of the base portion 1241 is different on the left and right, and the shapes of the right side surface 1243 and the left side surface 1244 are asymmetric. The leg 1249 is arranged to be largely shifted forward compared to the position of the previous leg 1250, and the legs 1249 and 1250 are separated by a large distance in the front-rear direction. Since the legs 1249 and 1250 are not arranged adjacent to each other in the left-right direction but are shifted front and back, an extending portion 1243a extending largely forward is formed near the lower side of the right side surface 1243, and the leg 1249 extends downward from the front end portion thereof. The legs 1249 and 1250 respectively penetrate through a through hole (not shown) formed in the circuit board 1150 from the front surface to the back surface side, and the portions protruding to the back surface side are soldered to be fixed to the circuit board 1150, and the upper arm set (arms 1251 and 1252) and the lower arm set (arms 1253 and 1254) are electrically connected to an electronic element mounted on the circuit board 1150.

[0147] Above the leg portion 1249, a bent portion 1243b bent leftward is formed to limit the insertion amount into the mounting hole 1151 (see FIG. 39) of the circuit board 1150. On the upper and lower sides of the bent portion of the bent portion 1243b, cutout portions 1243c and 1249a cut out in a semicircular shape are formed to facilitate the bending process. For positioning the rear leg portion 1250 on the circuit board 1150, step portions 1250a and 1250b formed on the front side and the rear side of the leg portion 1250 are used. The step portion 1250a is formed by extending the lower side portion of the left side surface 1244 forward, and the step portion 1250b is formed using the lower side portion of the bridge portion 1242 that curves in a U shape. In this way, by the step portions 1250a and 1250b coming into contact with the surface of the circuit board 1150, the vertical mounting position of the leg portion 1250 can be determined. The front-rear mounting positions of the leg portions 1249 and 1250 are defined by the position of the mounting hole 1151 (see FIG. 39) of the circuit board 1150.

[0148] FIG. 44(2) is a view of the signal terminal component 1240 alone as seen from the front lower side. As can be seen from this figure, a notch groove 1245b extending horizontally is formed on the front side of the arm base portion 1245, separating it into upper and lower arm sets (arms 1251, 1253). Also, the right leg portion 1249 is arranged so as to be largely displaced forward compared to the left leg portion 1250. As a result, even if an upward or downward force is applied to the four arms 1251, 1252, 1253, 1254, the signal terminal component 1240 can be firmly held on the circuit board. The external force applied to the arms 1251, 1252, 1253, 1254 is applied so as to push the arm set backward when the battery pack 1100 is attached to the power tool main bodies 1001, 1030, and this force is in the direction of tipping the signal terminal component 1240 backward. Conversely, when the battery pack 1100 is removed from the power tool main bodies 1001, 1030, it is a force that pushes the arm set forward, and this force is in the direction of tipping the signal terminal component 1240 forward. In this way, the external forces applied during attachment and removal of the battery pack 1100 can be effectively received by shifting the positions of the leg portions 1249, 1250 in the front-rear direction, and the mounting rigidity of the signal terminal component 1240 can be significantly enhanced, so that the durability of the battery pack 1100 can be improved. Furthermore, since the arm set is also formed in two stages, upper and lower, even when the power tool receives various vibrations or external forces during operation, a good contact state with the power tool main body side terminals can be maintained by the four contact regions of the arms. On the other hand, since the number of mounting holes of the circuit board 1150 and the number of soldering locations required when manufacturing this signal terminal component 1240 are the same as before, an increase in manufacturing cost can be suppressed.

[0149] The signal terminal component 1240 of this embodiment not only improves rigidity but also has other effects. Conventional signal terminal components (not shown) are provided with two legs for soldering to a circuit board and making electrical and mechanical attachments. However, these legs are arranged side by side in the left - right direction. The space between the legs is narrow and the soldering parts are often connected. As a result, it was not possible to route wiring such as signal patterns between the left and right legs. In the battery pack 1100 of this embodiment, one leg 1249 of the signal terminal component 1240 is arranged on the front side, and the other leg 1250 is arranged on the rear side, with both legs separated. This increases the distance between the legs of the signal terminal component 1240, making it easier to route multiple wirings or a thick pattern for flowing the main current. Such a signal terminal component 1240 is suitable when aiming to enhance the functionality of the battery pack 1100 of this embodiment, that is, the conventional battery pack, and promoting miniaturization in terms of voltage ratio. In particular, when increasing the voltage and implementing a voltage switching function, the number of electronic components mounted on the circuit board 1150 increases. Therefore, it becomes necessary to improve the efficiency of pattern wiring and thicken the wiring for flowing the main current. In this embodiment, a circuit board 1150 larger than the conventionally used one is employed, and electronic components are mounted not only in the rear region of the connection terminal group but also in the front region. At that time, wiring patterns are also arranged below the signal terminal component 1240. The method of this arrangement will be described with reference to FIG. 45.

[0150] FIG. 45 is a diagram showing the state of fixing a plurality of signal terminal components 1240 to a circuit board 1150, (1) is a view seen from the front, and (2) is a view of the signal terminal component 1240 seen from the left. The signal terminal component 1240 is a common component and is fixed side by side in the left-right direction on the circuit board 1150 as a T terminal 1164, a V terminal 1165, and an LS terminal 1166. Since the signal terminal component 1240 has a notch formed near the center of the arm portion so as to create a gap S2, the upper arm portion set (1251, 1252) and the lower arm portion set (1253, 1254) have a shape such that there are two levels vertically. In a state where no device-side terminal is mounted, the closest portions (fitting portions) of the upper arm portion set (1251, 1252) and the lower arm portion set (1253, 1254) are arranged so as to have a slight gap or to be in contact with each other. Each leg portion 1249, 1250 passes through a mounting hole (see FIG. 39) of the circuit board 1150 and projects to the lower side, and is fixed by solder 1256 on the lower side (back surface) of the circuit board 1150.

[0151] In the side view of Fig. 45(2), the distance between the front leg 1249 and the rear leg 1250 is configured to be separated by a distance S3. The distance S3 is preferably made larger than the distance between the legs 1249 and 1250 (the distance in the left-right direction). By forming a gap such as the arrow 1257 in this way, it becomes easy to wire the circuit pattern in this gap portion. Fig. 45(3) is a bottom view of the circuit board 1150 in Fig. 45(1) seen from below. On the back surface of the circuit board 1150, through holes are formed in the center for soldering the signal terminal components 1240, and lands 1153a - 1155a, 1153b - 1155b with substantially square soldering copper foils are arranged around the through holes. The wiring patterns for connecting from the lands 1153a - 1155a, 1153b - 1155b to the upper cell unit 1146 or the lower cell unit 1147 are on the surface side of the circuit board 1150 and are not visible in Fig. (3). The lands 1153a - 1155a for the left leg and the lands 1153b - 1155b for the right leg are arranged so as to be shifted in the front-rear direction. As a result, a plurality of patterns 1157 - 1159 can be arranged between the lands 1153a - 1155a and the lands 1153b - 1155b as shown in the figure. Here, the wiring patterns 1157 - 1159 are shown as three each, but they may be a single thick wiring or other combinations of numbers. Since the wiring patterns are arranged between the legs 1249 and 1250 shifted in the front-rear direction in this way, it is possible to provide a plurality of wiring patterns 1157 - 1159 that connect the rear side and the front side of the signal terminals 1164 - 1166 while keeping the intervals between the adjacent signal terminals 1164 and 1165, 1165 and 1166 the same as before. Incidentally, as another method of increasing the number of wiring patterns that connect the rear side and the front side of the signal terminals 1164 - 1166, a method of providing a cutout portion 1243c as shown by the dotted line in Fig. 45(2) may be used in combination. A cutout portion 1243c that is notched upward as shown by the dotted line is formed in the vicinity of the lower side of the right side surface 1243 at the portion in contact with the circuit board 1150. Then, the portion indicated by the arrow 1257 becomes a gap that is separated from the circuit board 1150.It is possible to arrange circuit patterns between this gap and the circuit board 1150 in the same way as the wiring patterns 1157 to 1159 in FIG. 45(3). Thus, since it is possible to arrange a plurality of wiring patterns that connect the rear side and the front side of the signal terminals 1164 to 1166 not only on the back side 1150b but also on the front side 1150a of the circuit board, it is possible to improve the execution efficiency of the circuit board 1150.

[0152] FIG. 46 is a diagram showing the shape of the connection terminal group (1161 to 1162, 1164 to 1168) and the board cover 1180 arranged around it. (1) is a perspective view, and (2) is a front view. Here, for the sake of understanding the invention, the illustration of the circuit board 1150 is omitted. In an actual product, after a plurality of connection terminal groups (1161 to 1162, 1164 to 1168, 1171, 1172, 1177) are fixed to the circuit board 1150 by soldering, the board cover 1180 is attached around the connection terminals. The power terminals (1161, 1162, 1167) are formed to be higher by a distance H upward than the signal terminals (1164 to 1166, 1168). The board cover 1180 is a member manufactured from a non-conductor, for example, a molded product of synthetic resin, and is a member that covers the periphery of the legs of adjacent connection terminals. It has a connecting portion 1181 having a flat upper surface 1181a on the front side, and a plurality of partition walls 1182, 1183, 1184 to 1189 are connected to the rear side of the connecting portion 1181. The partition walls 1182, 1183, 1184 to 1189 are arranged on the rear side of the flat portion 1181a, that is, on the left and right portions of the connection terminal group, and function to make it difficult for an electrical short circuit to occur between the connection terminals. Also, the upper surface 1181a of the connecting portion 1181 is formed to be flush with the upper surface 1115 (see FIG. 38) of the upper case 1110, facilitating the relative movement of the main body side terminal portion from the upper surface 1115 to the connecting portion 1181. Further, the board cover 1180 is provided with a covering portion 1184 that closes the opening of the unused area (slot 1123 in FIG. 38), making it difficult for dust and dirt to enter the case inside the battery pack 1100 from the slot 1123.

[0153] The substrate cover 1180 is mainly formed by a connecting portion 1181 having a horizontally horizontal upper surface 1181a in the horizontal direction and a plurality of partition wall portions extending above it. Among the partition wall portions, the partition walls 1185, 1186, and 1189 disposed between the signal terminals are low walls with a height H2, and the upper end positions thereof are lower than the lower arm portions of the signal terminals (1164 to 1166) and the LD terminal 1168. On the other hand, the partition walls 1182, 1183, 1184, 1187, and 1188 adjacent to the power terminals are high walls with a height H3 from the upper surface 1181a, and the upper end positions thereof are configured to be located above the upper end positions of the lower terminal components and below the lower arm portions of the upper terminal components.

[0154] Among the connection terminal groups, the power terminals are arranged such that the legs of the upper positive terminals 1161 and 1162 and the lower positive terminals 1171 and 1172 are arranged in the front-rear direction, and the respective arm sets are arranged side by side in the vertical direction as described with reference to FIGS. 40 to 43. Similarly, the legs of the upper negative terminal 1167 and the lower negative terminal 1177 are arranged in the front-rear direction, and the respective arm sets are arranged side by side in the vertical direction. When the battery pack 1100 is mounted on the electric device main body rated at 18V, the potentials of the arms of the upper positive terminals 1161 and 1162 and the upper negative terminal 1167 are the same as the potentials of the lower positive terminals 1171 and 1172 and the lower negative terminal 1177. Therefore, there is no problem even if the upper and lower terminal components come into contact. However, when the battery pack 1100 is mounted on the electric device main body rated at 36V, the potentials of the upper positive terminals 1161 and 1162 and the upper negative terminal 1167 are different from the potentials of the lower positive terminals 1171 and 1172 and the lower negative terminal 1177, respectively. Therefore, it is important to prevent a short-circuit state due to contact between the upper and lower arms. Also, it is preferable to have a shape that is less likely to cause a short circuit due to the insertion of foreign matter. Therefore, in the substrate cover 1180 of the present embodiment, among the partition wall portions formed to extend upward from the connecting portion 1181, the upper end positions of the partition walls 1182, 1183, 1184a, 1187, and 1188 are largely formed upward so as to have a height H3. In addition, not only the wall portions extending vertically upward but also the horizontal wall portions extending in the left-right direction from the upper end positions of the vertical wall portions are formed.

[0155] FIG. 46(3) is an enlarged partial view of the substrate cover 1180 in (2), and is a view excluding the illustration of the connection terminal portion. The partition wall 1182 has a vertical wall portion 1182a and a horizontal wall portion 1182b, and its cross-sectional shape is L-shaped. The horizontal wall portion 1182b extends horizontally so as to reach into the space between the arms of the adjacent power terminals (upper positive terminal 1161 and lower positive terminal 1171) near the upper end of the vertical wall portion 1182a. Further, the partition wall 1183 has a T-shaped cross-sectional shape and is formed by a vertical wall portion 1183a and horizontal wall portions 1183b and 1183c extending in both directions from the upper end portion of the vertical wall portion 1183a. The horizontal wall portion 1183b extends toward the side close to the adjacent horizontal wall portion 1182b, and has a length such that the tip reaches into the space between the arms of the upper positive terminal 1161 and the lower positive terminal 1171. Similarly, the horizontal wall portion 1183c extends toward the side close to the adjacent horizontal wall portion 1184b, and has a length such that the tip reaches into the space between the arms of the upper positive terminal 1162 and the lower positive terminal 1172. The situation where the horizontal wall portions 1182b, 1183b, and 1183c extend into the space between the arms will be apparent by viewing the positive terminal group from the front as shown in FIG. 46(2). For example, the right side surface position of the upper positive terminal 1161 and the right side surface position of the lower positive terminal 1171 are at the same position. However, the left end position 1182c of the horizontal wall portion 1182b extends to the lower side portion of the arm portion 1161a of the upper positive terminal 1161 so as to extend to the left of the right side surface positions of the upper positive terminal 1161 and the lower positive terminal 1171. Note that the horizontal wall portion 1182b is located above the arm portion 1171a of the lower positive terminal 1171.

[0156] The longitudinal length of the vertical wall portion 1182a and the horizontal wall portion 1182b in the front-rear direction is formed to be longer than the longitudinal length of the lower positive electrode terminal 1171. The front end position thereof is substantially the same as the tip of the arm portion of the lower positive electrode terminal 1171, and the rear end position is on the rear side of the rear end position of the lower positive electrode terminal 1171. In this way, the vertical wall portion 1182a covers the entire right side surface and the entire left side surface of the lower positive electrode terminal 1171, and also covers the upper portion except for the vicinity of the left and right center (the portion of the distance S5). Here, only the shapes of the vertical wall portion 1182a and the horizontal wall portion 1182b of the lower positive electrode terminal 1171 portion have been mentioned. However, for the lower positive electrode terminal 1172, a partition wall 1184 is provided so that the entire right side surface, the entire left side surface, and the upper portion except for the central portion are covered. Therefore, even if an external force is applied to the lower positive electrode terminals 1171 and 1172 to bend them, they can be effectively held by the substrate cover 1180, and the risk that the lower terminal component and the upper terminal component for power transmission are short-circuited unintentionally can be significantly reduced.

[0157] Regarding the negative terminal side (1167, 1177), the same concept as the positive terminal side (1161, 1162, 1171, 1172) is applied, and large partition walls 1187 and 1188 are provided on both the left and right sides of the negative terminal. The partition wall 1187 has the same shape as the partition wall 1182, is formed by a vertical wall portion 1187a and a horizontal wall portion 1187b, and has an L-shaped cross-sectional shape. The horizontal wall portion 1187b is formed to extend from the upper end portion of the vertical wall portion 1187a toward the negative terminal side. The partition wall 1188 is formed symmetrically to the partition wall 1187 with respect to the left and right, and is formed by a vertical wall portion 1188a and a horizontal wall portion 1188b. The horizontal wall portions 1187b and 1188b are sized such that the tip portions enter the space between the arm sets of the upper negative terminal 1167 and the arm sets of the lower negative terminal 1177, but have a predetermined interval S5 so as not to prevent the device-side terminals such as the power tool main bodies 1001 and 1030 from entering. Since the partition walls 1187 and 1188 are formed to cover the periphery of the negative terminals (1167, 1177) which are power terminals, even if a strong external pressure is applied to the upper negative terminal 1167 or the lower negative terminal 1177 and it moves (is bent) in the front-rear direction, the possibility of a short-circuit phenomenon occurring can be significantly reduced due to the presence of wall portions such as the horizontal wall portions 1187b and 1188b.

[0158] The partition walls 1185 and 1186 between the signal terminal groups (1164 - 1166) have only a low height H2 in the upward direction. This is because only small-power signals flow through the signal terminal groups (1164 - 1166), so the degree of danger during a short circuit is significantly smaller compared to the power terminal side. Also, since each of the signal terminal groups (1164 - 1166) is a single component and the upper arm portion and the lower arm portion are at the same potential, there is little need to worry about a short circuit. The partition wall 1184 includes vertical wall portions 1184a and 1184d, and a closing plate 1184c connects between them. The closing plate 1184c is a flat plate extending in the vertical and left-right directions, and functions to close the empty space (the internal space of the empty slot 1123 in FIG. 38) between the upper positive terminal 1162 and the T terminal 1164. A horizontal wall portion 1184b extending toward the positive terminal side is formed near the upper end of the vertical wall portion 1184a.

[0159] The connecting part 1181 is configured to fix the vertical wall parts 1182a, 1183a, 1184a, 1184d, 1185a, 1186a, 1187a, 1188a located between the connection terminals by connecting to their front surfaces. The wall part on the upper surface 1181a of the connecting part 1181 is formed to be in a floating state relative to the circuit board 1150. The inner part of the connecting part 1181 is formed to have a space, and the vertical wall parts 1184a, 1185a, 1187a are arranged on the rear side thereof. Here, although they are hidden behind the front wall surface 1181b and not visible, the vertical wall parts 1182a, 1183a, 1184d, 1188a are similarly formed to extend to the lower side and contact the circuit board 1150. After the inner part of this connecting part 1181 is filled with a liquid curable resin that covers the upper surface of the circuit board 1150 as described later with reference to FIG. 48, it is hardened. By the solidification of the curable resin, the vicinity of the lower ends of the plurality of vertical wall parts 1182a, 1183a, 1184a, 1184d, 1185a, 1186a, 1187a, 1188a and the circuit board 1150 are firmly fixed. Three notch parts 1181c to 1181e are formed on the front wall surface 1181b of the connecting part 1181. The notch parts 1181c to 1181e are formed to enable the liquid resin described later with reference to FIG. 48 to evenly spread to the rear part and the front part of the circuit board 1150. Since the liquid resin has a relatively low viscosity, the resin flows in the front-rear direction through the notch parts 1181c to 1181e (details will be described later).

[0160] FIG. 47 is a view showing only the upper case 1110 of FIG. 38, and is a view for explaining the shape of the upper surface 1115 of the upper case 1110. FIG. 47(1) is a perspective view of the upper case 1110, and (2) is a view seen from the direction of arrow B in (1). In (1), hatching is applied to the stepped portion so that the range is clearly shown. As described with reference to FIG. 46, the power terminals (1161, 1162, 1167) are formed to be higher by a distance H in the upward direction than the signal terminals (1164 to 1166, 1168). This is because the power terminals are formed of a thicker plate material than the signal terminals. Therefore, in the shape of the upper surface of the conventional upper case, the upper ends of the power terminals (1161, 1162, 1167) interfere with the inner wall of the upper surface. Therefore, in the present embodiment, the position of the inner wall surface of the upper surface 1115 of the upper case 1110 in the vertical direction is partially shifted upward so as to provide a clearance above the power terminals (1161, 1162, 1167). Although a method of making only the position of the inner wall surface a recess that is recessed upward can be considered, if the screen shape of the upper surface 1115 is left as it is, the thickness of a part of the upper surface 1115 of the upper case 1110 may be insufficient, and the strength may locally decrease. Therefore, in the present embodiment, convex portions 1115a and 1115b that protrude outward are formed on the outer surface of the upper surface 1115 in the vicinity where the power terminals (1161, 1162, 1167) are located. Since the wall surface of the upper surface 1115 is configured to be partially shifted upward in this way, the accommodation space can be expanded in the inner portion, and a decrease in the wall surface strength can be prevented. In the present embodiment, the protruding height H4 of the outer wall surface of the upper surface 1115 is configured to be smaller than the recessed height H5 of the inner wall surface, so that the sizes of the convex portions 1115a and 1115b can be kept small on the upper surface 1115 and are within a range where they can be mounted on the conventional power tool body 1001 without any problem. Further, since the upper surface 1115 is not the same surface and a partial step portion is formed so that the height of the mesh portion becomes higher, the strength can be made equal to or higher than that of the conventional flat upper case.

[0161] Next, a method for applying resin to the circuit board 1150 will be described with reference to FIG. 48. FIG. 48 is a perspective view of the circuit board 1150. Although not shown here, a main region 1156a and a sub-region 1156b for mounting electronic elements are provided on the upper surface (front surface) of the circuit board 1150. The main region 1156a is located on the rear side of the connection terminal group, and a protection management IC (described later) including a microcontroller is mounted thereon. The sub-region 1156b is a region on the front side of the connection terminal group. Here, the entire mounted electronic element is covered with a curable resin. The curable resin cures from a liquid state, and for example, a urethane resin can be used. In order to evenly fill the upper surface of the circuit board 1150 with liquid urethane resin, first, an adhesive resin 1155 that serves as a dike to prevent the outflow of the liquid resin is attached to the outer edge portion of the element group initially mounted on the circuit board 1150. The adhesive resin 1155 is continuously attached along the outer edge of the region where the urethane resin is to be filled by, for example, extracting a cylindrical adhesive from a tube-shaped container through a thin extraction port. At this time, it is important that the adhesive is attached to the outer edge portion without interruption, and it is formed such that one end and the other end are in contact with the substrate cover 1180. After attaching the adhesive resin 1155 that serves as an outer frame to approximately one round of the outer edge portion where the resin is to be poured, the liquid urethane resin is then poured into the inner side of the upper surface of the circuit board 1150.

[0162] The amount of the urethane resin to be poured in shall be an amount that sufficiently fills the range surrounded by the adhesive resin 1155. At this time, for the portions that are not desired to be covered with the resin, the outer edges of the corresponding portions are surrounded by the adhesive resin 1155a so that the resin poured outside thereof does not reach within the range surrounded by the adhesive resin 1155a. In addition, if the position where the urethane resin is poured in is near the position indicated by the arrow 1156a in the main region, the resin will not flow into the range surrounded by the adhesive resin 1155a. Further, in the substrate cover 1180, the wall surface of the connecting portion 1181 forming the upper surface 1181a floats, the rear side wall surface of the lower portion thereof is in an open state, the front side is a wall surface, and notches 1181c to 1181e are formed in a part thereof, so that the resin can flow well from the main region 1156a to the sub-region 1156b. In this way, after covering the entire element mounting surface of the circuit board 1150 with the resin and then curing it, the surface side of the circuit board 1150 can be covered with the resin without gaps at a uniform height within the target range, and the mounted electronic elements can be protected from the influence of water and dust. In addition, when a double-sided substrate is used as the circuit board 1150, the back side may also be covered with the resin in the same procedure. Also, for the portions where the filling of the resin is excluded by the adhesive resin 1155, such as near the screw holes and the soldering portions of the lead wires, the resin may be applied in the subsequent process after the screw tightening is completed or in the subsequent process after the soldering is completed.

[0163] The sixth embodiment of the present invention has been described above with reference to FIGS. 36 to 48. However, the battery pack 1100 shown in the sixth embodiment can be variously modified. FIG. 49 is a diagram showing the shapes of the upper terminal component 1260 and the lower terminal component 1280 according to the first modification of the sixth embodiment. FIG. 49(1) is a perspective view, (2) is a left side view, and (3) is a front view. The upper terminal component 1260 and the lower terminal component 1280 each have two sets of arms (1265 and 1266, 1285 and 1286) in the left-right direction, and the point that the two sets of arms are aligned in the up-down direction is the same as that in the sixth embodiment. The arrangement that the leg sets (1267, 1268) of the upper terminal component 1260 are arranged side by side in the front-rear direction with the leg sets (1287, 1288) of the lower terminal component 1280 is the same as that in the sixth embodiment. On the lower portions of the rear sides of the right side surface 1263 and the left side surface 1264, as shown by arrows 1262a and 1282a in (2), the bridge portions 1262 and 1282 protrude so as to be curved rearward. This protruding portion is used for vertical positioning when the upper terminal component 1260 and the lower terminal component 1280 are attached to the circuit board 1150. On the upper portions of the front sides of the legs 1267 and 1268, bent portions 1263a, 1264a, 1283a, and 1284a (where 1263a is not visible in FIG. 49) are formed by bending the convexly extended portions inward. These shapes are the same as the configuration of the sixth embodiment shown in FIG. 40.

[0164] The bending direction of the U-shaped upper terminal component 1260 is different from the direction shown in FIG. 40. Here, the portion that becomes the bottom when bent into a U shape, that is, the bridge portion 1262, is formed so as to be a vertical plane. The bending shape of the lower terminal component 1280 is the same as that of the lower terminal component 1220 shown in FIG. 40 in terms of the U-shaped bending direction, and the bridge portion 1282 is a vertical plane. The bridge portions 1262 and 1282 are arranged in parallel so as to have a substantially constant interval in the front-rear direction, and they are arranged so as to extend in a direction substantially perpendicular to the surface of the circuit board 1150. The upper terminal component 1260 and the lower terminal component 1280 are manufactured by pressing a metal flat plate, which is the same as in the sixth embodiment, but the thickness of the flat plate is further increased.

[0165] The right side surface 1263 and the left side surface 1264 are substantially rectangular extending in the vertical direction, and are formed such that the arm portions 1265 and 1266 extend forward at a portion near the upper end. Near the rear base of the arm portions 1265 and 1266, that is, near the chain line B2, the width (the length in the vertical direction) is large, and the width gradually decreases as going forward, and the width becomes constant on the further forward side than the virtual line B1. In the fitting portions 1265d and 1266d, the points bent into a curved surface shape having a predetermined radius of curvature R1 inward in the top view are the same as those in the sixth embodiment shown in FIG. 40. Thus, the arm portions 1265 and 1266 are formed so as to extend forward from the upper front side portion of the U-shaped base portion, and the arm portions 1265 and 1266 are formed to have spring properties in a non-contact state with each other.

[0166] The lower terminal component 1280 has a right side surface 1283 and a left side surface 1284 that are formed by being bent into a U shape and are parallel to each other, and a bridge portion 1282 that connects them. Arms 1285 and 1286 are provided so as to extend forward and obliquely upward from the elongated upper portions of the right side surface 1283 and the left side surface 1284. The vertical width of the arms 1285 and 1286 is substantially constant in the front-rear direction, and is formed to extend horizontally on the front side of the virtual line B1, but is arranged obliquely on the rear side of the virtual line B1. A notch portion 1291 that is largely cut out from the front side is formed below the arm set (1285, 1286) of the lower terminal component 1280. As a result of forming in this way, the lengths of the arms 1265 and 1266 of the upper terminal component 1260 (the length in the front-rear direction and in front of B2) are longer than the lengths of the arms 1285 and 1286 of the lower terminal component 1280 (the length in the front-rear direction and on the front side of the position of the arrow 1291). Even for such a set of arms with different lengths in the front-rear direction, it is preferable that the fitting pressure at the fitting portion of the upper terminal component 1260 is the same as the fitting pressure of the lower terminal component 1280. If the fitting pressure is not made uniform, the contact resistance with the flat device-side terminals on the side of the power tool main bodies 1001 and 1030 will change, resulting in a slight difference in heat generation or a difference in wear conditions due to long-term use. In this modification example, in order to balance the fitting pressures by the upper terminal component 1260 and the lower terminal component 1280, the initial gap intervals in the non-mounted state of the battery pack are made different. That is, in the state where the battery pack 1100 is not mounted on the power tool main body 1001 or 1030 (the removed state), the minimum interval between the left and right arms 1265 and 1266 is different from the interval between the arms 1285 and 1286. Here, the interval between the arms 1265 and 1266 of the upper terminal component 1260 is 0.2 mm, while the minimum interval between the arms 1285 and 1286 of the lower terminal component 1280 is set to 0.5 mm.

[0167] In order to make the fitting pressure uniform, the shapes of the upper terminal component 1260 and the lower terminal component 1280 were also devised. That is, as shown in Fig. 49(2), where the upper terminal component 1260 would originally form a substantially right-angled inner corner like the dotted line 1264b, here the contour of the dotted line 1264b is extended in the direction of the arrow 1264e to form a shape such that a reinforcing surface 1264c in an isosceles triangle shape in side view is added. As a result, the contour of this inner corner part becomes oblique like the arrow 1264d, and by this shape change, the mounting rigidity of the arm parts 1265 and 1266 of the upper terminal component is improved. In accordance with the shape change of the inner corner part of the upper terminal component 1260, the shape of the outer corner part of the lower terminal component 1280 is cut off from the part of the dotted line 1284b in the direction of the arrow 1284e to form a shape such that a cut-off part 1284c in an isosceles triangle shape in side view is provided. As a result, the contour of this outer corner part becomes like the arrow 1284d, and the rigidity of the arm parts 1285 and 1286 of the lower terminal component is reduced. The contour parts shown by the arrow 1264d and the arrow 1284d are determined so as to be separated by a certain interval so as to be substantially parallel to each other in side view. Incidentally, when the cut-off part 1284c is formed, the vertical length of the bridge part 1282 becomes shorter. However, since the lower terminal component 1280 is small, it is sufficiently strong in terms of strength compared to the upper terminal component 1260, so these shape changes just achieve a strength balance. In this way, by changing the shape of the inner corner part of the upper terminal component 1260 by adding the reinforcing surface 1264c and changing the shape of the outer corner part of the lower terminal component 1280 by forming the cut-off part 1284c to adjust the strength, the strength balance between the two is achieved, and the fitting pressure of the body-side terminals by the arm parts 1265 and 1266, 1285 and 1286 can be made substantially equal.

[0168] Figure 49(3) is a front view of the upper terminal component 1260 and the lower terminal component 1280. The vertical heights and mounting positions of the arms 1265 and 1266, and the vertical heights and mounting positions of the arms 1285 and 1286 are the same in shape and positional relationship as the arm groups of the upper terminal component 1200 and the lower terminal component 1220 of the sixth embodiment shown in Figure 40. However, in this modified example, the thickness of the metal plate used is different, and it is manufactured using a thicker plate than the terminal components of the sixth embodiment shown in Figure 40. Furthermore, in the state where the battery pack 1100 is not mounted, the minimum interval between the upper and lower arm sets is made different. That is, the lateral interval between the lower arms 1285 and 1286 is configured to be larger than the lateral interval between the upper arms 1265 and 1266. This is a relationship inversely proportional to the lengths of the arms 1265 and 1266, and the arms 1285 and 1286 arranged side by side in the vertical direction in the mounting direction (front-rear direction). The long arms 1265 and 1266 face each other at a narrow interval in the initial state. Conversely, the short arms 1285 and 1286 face each other at a wide interval.

[0169] As described above, in the first modified example, the upper terminal component 1260 and the lower terminal component 1280 with a plate thickness of 0.8 mm are used as power terminals. Since only a very small current flows through the signal terminal component, it may be manufactured using a metal plate with a thickness of about 0.3 mm as in the conventional battery pack 1015. In this modified example, the rigidity of the power terminal through which a large current flows is further improved, and the fitting condition can be maintained well not only during operation but also over a long period of use. In addition, to make the fitting pressure of the upper and lower arm sets substantially the same, it is not limited to only adjusting the gap of the fitting part and changing the shape near the mounting base, but can also be achieved by other changes, particularly adjusting the plate thickness, selecting the material of the terminal component, etc.

[0170] FIG. 50 is a perspective view showing an upper terminal component 1260 and a lower terminal component 1280A of a second modification of the sixth embodiment. In the second modification, the upper terminal component 1260 is the same as that of the first modification shown in FIG. 49, but the lower terminal component 1280 has a different plate thickness and an initial interval between the arms. That is, after reducing the plate thickness of the lower terminal component 1280A from 0.8 mm of the lower terminal component 1280 shown in FIG. 49 to 0.6 mm, the interval between the fitting portions 1285d and 1286d is narrowed from 0.5 mm of the lower terminal component 1280 shown in FIG. 49 to 0.2 mm. The interval between the fitting portions 1265d and 1266d of the upper terminal component 1260 is 0.2 mm as in the first modification. Thus, by adjusting the plate thickness and the interval of the spring-like arms 1285 and 1286, it can be made substantially equal to the fitting pressure by the fitting portions 1265d and 1266d of the upper terminal component 1260. Here, the shapes of the fitting portions 1265d and 1266d are semi-cylindrical surfaces, the central axis of the cylindrical surface is located in the vertical direction, and the inner wall surfaces of the fitting portions 1265d and 1266d are cylindrical surfaces with a curvature radius R1. The inner wall surfaces of the fitting portions 1285d and 1286d of the lower terminal component 1280 are also formed to be cylindrical surfaces with a curvature radius R1. The cylindrical shapes of the fitting surfaces of these fitting portions 1265d and 1266d, and the fitting portions 1285d and 1286d are preferably formed with the same curvature radius R1 so that the sizes and shapes of the linear or rectangular contact portions are substantially the same. By making the sizes of the contact portions and the contact regions uniform in this way, it is preferable to make the clamping pressure (fitting pressure) substantially equal and the electrical contact resistance substantially the same.

[0171] FIG. 51 is a perspective view showing an upper terminal component 1200A and a lower terminal component 1220 according to a third modification of the sixth embodiment, and (1) is a view showing a state in which these are connected to the main body side terminals of an electric power tool main body 1030A with a rated voltage of 36V. In the third modification, only the shape of the upper terminal component 1200A, particularly the shape of the arm portions 1205A and 1206A, is different from that of the sixth embodiment, and the configuration of the base portion and the leg portions of the upper terminal component 1200A is the same as that of the sixth embodiment. The upper terminal component 1200A is used as upper positive terminals 1161 and 1162 and an upper negative terminal 1167. The upper terminal component 1200A extends the arm portions 1205A and 1206A greatly forward so that the positions of the fitting portions of the upper arm portions 1205A and 1206A are located more forward than the positions of the fitting portions of the lower arm portions 1225 and 1226. The shapes of the opposing fitting portions are semi-cylindrical surfaces having an equal radius of curvature R1, and the shapes of the fitting portions of the arm portions 1205A and 1206A are the same as the shapes of the fitting portions of the arm portions 1225 and 1226. When extending the arm portions 1205A and 1206A, the positive input terminal 1072A of the 36V side electric power tool main body is also made shorter than before in correspondence with this shape change. The size and plate thickness of the short bar 1079 as the short-circuit means are the same as those of the short bar 1059 shown in FIG. 41. However, a semi-circular notch 1079d is formed in the upper part of the terminal portion 1079b of the short bar 1079. This notch 1079d is to prevent the terminal portion 1079b from contacting the upper arm portions 1205A and 1206A when the positive input terminal 1072A of the device side terminal and the terminal portion 1079b move relative to each other in an arc shape like the arrow 1045a or in the horizontal direction for some reason. Since the notch 1079d is formed in the terminal portion 1079b of the short bar 1079 in this way, even if a relative displacement occurs due to the difference in the resonance frequencies of the electric power tool main body 1030 and the battery pack 1100 when the battery pack 1100 is mounted and the electric power tool is operating, the risk of a short circuit between the upper terminal component 1200A and the lower terminal component 1220 can be significantly reduced.

[0172] FIG. 51(2) is a diagram showing a state where it is connected to the main body side terminal of a conventional power tool main body 1001. When attaching it to the 18V rated power tool main body 1001 side, the upper positive terminal 1162 and the lower positive terminal 1172 are connected to the positive input terminal 1022 so as to straddle, and the two sets of arm portions 1205A, 1206A and the arm portions 1225, 1226 are fitted. At this time, the contact position of the positive input terminal 1022 by the fitting portions of the arm portions 1205A, 1206A is shifted to the front side from the contact position of the positive input terminal 1022 by the fitting portions of the arm portions 1225, 1226. However, since the thickness of the positive input terminal 1022 in the vicinity including each contact position is uniform, if the size of the contact portion or contact area is equal between that by the arm portions 1205A, 1206A and that by the fitting portions of the arm portions 1225, 1226, a good conduction state can be realized, so the movement of the contact position does not cause any problems.

[0173] FIG. 52 is a perspective view showing the upper terminal component 1200 and the lower terminal component 1220A of the fourth modification of the sixth embodiment, and (1) is a diagram showing a state where these are connected to the main body side terminal of the power tool main body 1030B. In the fourth modification, only the shapes of the arm portions 1225A, 1226A of the lower terminal component 1220A are different from those of the sixth embodiment, and the other configurations are the same as those of the sixth embodiment. Here, the arm portions 1225A, 1226A are extended forward so that the positions of the fitting portions of the lower arm portions 1225A, 1226A are located in front of the positions of the fitting portions of the upper arm portions 1205, 1206. Correspondingly, the rear end position of the short bar 1079 is also made more forward than before. Further, a semicircular notch 1072d is formed at the lower part of the positive input terminal 1072B. This notch 1072d is provided to greatly reduce the possibility that the positive input terminal 1072B contacts the arm portions 1225A, 1226A when the positive terminal 1072B of the device side terminal and the terminal portion 1079b move in the direction of arrow 1045b for some reason.

[0174] FIG. 52(2) is a diagram showing a state where it is connected to the main body side terminal of the conventional electric tool main body 1001. Two sets of arm portions 1205 and 1206 and arm portions 1225A and 1226A are fitted to the positive input terminal 1022 on the electric tool main body 1001 side. Here, the positions of the contact portions by the arm portions 1205 and 1206 and the positions of the contact portions by the arm portions 1225A and 1226A are separated by a distance L in the front-rear direction. However, since the sizes of the contact portions or contact regions by the arm portions 1205 and 1206 and the fitting portions of the arm por...

Claims

1. A plurality of cell units each having at least one cell, A housing for accommodating the plurality of cell units, having a lower surface, an upper surface formed higher than the lower surface at the rear of the lower surface, a stepped portion formed between the lower surface and the upper surface, a plurality of slots extending rearward from the stepped portion so that terminals of an electrical device body can be inserted into the upper surface, and a pair of rails spaced apart in the left-right direction and extending in the front-rear direction, and configured to be mounted by being moved forward with respect to the electrical device body along the pair of rails; A positive terminal connected to the positive electrode of the first cell unit constituting the plurality of cell units, and a negative terminal connected to the negative electrode of the second cell unit constituting the plurality of cell units and arranged apart from the positive terminal in the left-right direction, and a plurality of power terminals directly connected to the terminals of the electrical device body; A switching terminal provided separately from the positive terminal and the negative terminal and configured to switch the connection state of the plurality of cell units when directly connected to the terminals of the electrical device body; A battery pack having When the battery pack is moved forward with respect to the electrical device body along the pair of rails and mounted on the electrical device body, the positive terminal, the negative terminal, and the switching terminal are arranged in the plurality of slots extending rearward from the stepped portion so as to be able to fit with the terminals of the electrical device body; When connected to a first electrical device body as the electrical device body, the switching terminal directly fits with the terminals of the electrical device body and the first cell unit and the second cell unit are connected in series; When connected to a second electrical device body as the electrical device body, the switching terminal directly fits with the terminals of the electrical device body and the first cell unit and the second cell unit are connected in parallel; When removed from the electrical device body, the connection between the switching terminal and the terminals of the electrical device body is released so that the first cell unit and the second cell unit are not connected; A battery pack characterized by the above.

2. The battery pack according to claim 1, The positive terminal, the negative terminal, and the switching terminal are arranged within the region of the stepped portion in the up-down direction and within the plurality of slots in the front-rear direction; A battery pack characterized by the above.

3. The battery pack according to claim 1, The switching terminal is A first switching terminal connected to the positive electrode of cell units other than the first cell unit among the plurality of cell units; A second switching terminal connected to the negative electrode of cell units other than the second cell unit among the plurality of cell units; and having The first switching terminal and the positive electrode terminal are located inside the first slot among the plurality of slots, being close to and separated from each other in the vertical direction. The second switching terminal and the negative electrode terminal are located inside the second slot among the plurality of slots, being close to and separated from each other in the vertical direction. A battery pack characterized by the above.

4. The battery pack according to claim 3, In the vertical direction, a first partition wall made of resin is provided between the first switching terminal and the positive electrode terminal, and a second partition wall made of resin is provided between the second switching terminal and the negative electrode terminal. A battery pack characterized by the above.

5. An electric device comprising a battery pack having a plurality of cell units, and a first electric device main body to which the battery pack can be connected. The battery pack includes A housing for accommodating the plurality of cell units, having a lower surface, an upper surface formed higher than the lower surface at the rear of the lower surface, a stepped portion formed between the lower surface and the upper surface, a plurality of slots extending rearward from the stepped portion so that a positive electrode input terminal, a negative electrode input terminal, and a switching element can be inserted into the upper surface, and a pair of rails spaced apart in the left-right direction and extending in the front-rear direction, and the housing is configured to be movable forward with respect to the first electric device main body along the pair of rails and be mounted; A positive electrode terminal connected to the positive electrode of the first cell unit constituting the plurality of cell units and directly connected to the positive electrode input terminal; A negative electrode terminal connected to the negative electrode of the second cell unit constituting the plurality of cell units, arranged apart from the positive electrode terminal in the left-right direction, and directly connected to the negative electrode input terminal; A switching terminal provided separately from the positive electrode terminal and the negative electrode terminal, and configured to switch the connection state of the plurality of cell units when directly connected to the switching element; and having The first electric device main body includes A pair of rail grooves that fit with the pair of rails; A positive electrode input terminal and a negative electrode input terminal that directly fit with the positive electrode terminal and the negative electrode terminal respectively; A switching element configured to directly fit with the switching terminal and switch the connection state of the plurality of cell units to a series connection state. ​ a terminal section where the positive input terminal, the negative input terminal, and the switching element are disposed; having; when the battery pack is moved forward relative to the first electric device body along the pair of rails and attached to the first electric device body, the positive terminal, the negative terminal, and the switching terminal are arranged so as to be respectively fitted into the plurality of slots extending rearward from the step portion; An electric device characterized by the above.

6. An electric device comprising: a battery pack having a plurality of cell units; a second electric device body to which the battery pack can be connected; The battery pack includes: a housing that houses the plurality of cell units, having a lower surface, an upper surface formed higher than the lower surface at the rear of the lower surface, a step portion formed between the lower surface and the upper surface, a plurality of slots extending rearward from the step portion so that a positive input terminal, a negative input terminal, and a switching element can be inserted into the upper surface, and a pair of rails spaced apart in the left-right direction and extending in the front-rear direction, and is configured to be movable forward relative to the second electric device body along the pair of rails and attached; a positive terminal connected to the positive electrode of the first cell unit constituting the plurality of cell units and directly connected to the positive input terminal; a negative terminal connected to the negative electrode of the second cell unit constituting the plurality of cell units, disposed apart from the positive terminal in the left-right direction, and directly connected to the negative input terminal; a switching terminal provided separately from the positive terminal and the negative terminal and configured to switch the connection state of the plurality of cell units when directly connected to the switching element; having; The second electric device body includes: a pair of rail grooves that fit with the pair of rails; a positive input terminal and a negative input terminal that respectively directly fit with the positive terminal and the negative terminal; a switching element configured to directly fit with the switching terminal and switch the connection state of the plurality of cell units to a parallel connection state; a terminal section where the positive input terminal, the negative input terminal, and the switching element are disposed; having. When the battery pack is moved forward relative to the second electric device main body along the pair of rails and attached to the second electric device main body, the positive terminal, the negative terminal, and the switching terminal are arranged so as to be respectively fitted into the plurality of slots extending rearward from the step portion, within which the positive input terminal, the negative input terminal, and the switching element can be respectively fitted. An electric device characterized by this.

7. An electric device according to Claim 6, wherein the positive input terminal and the negative input terminal function as the switching element. An electric device characterized by this.

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