Battery pack, first electrical device body, and second electrical device body

Abstract

A battery pack, a first electrical device body, and a second electrical device body are provided. In a battery pack in which connection states of a plurality of battery cells can be switched, a control unit for controlling discharge of the battery pack stably operates, and in a battery pack in which an output voltage can be switched, voltage balance between cell units is achieved. The battery pack has cell units in which upper and lower battery cells are connected in series, and switching of series or parallel connection output is performed, in which a protection circuit that monitors a state of the battery cells is provided for each cell unit, and only the protection circuit on the lower cell unit side is provided with a control unit having a microcomputer. In order to adjust power consumption of the microcomputer provided only on the lower cell unit, a consumption current control member having a dummy load is provided in a circuit on the upper cell unit side. The consumption current control member operates in conjunction with activation of the microcomputer of the control unit, thereby making power consumption on the upper and lower cell unit sides equal.

Description

[0001] This application is a divisional application of the original application number 201880038918.1, filed on May 30, 2018 (priority date June 16, 2017), entitled "Battery Pack and Electrical Equipment Using a Battery Pack". Technical Field

[0002] This invention relates to an electrical device having a load such as a motor or lighting, and a battery pack for supplying power to such electrical device. Background Technology

[0003] Power tools and other electrical equipment are being driven by battery packs containing rechargeable batteries such as lithium-ion batteries, advancing the cordless transformation of electrical devices. For example, in handheld power tools that use a motor to drive the front-end tool, a battery pack containing multiple rechargeable battery cells is used, utilizing the electrical energy stored in the battery pack to power the motor. The battery pack is detachably integrated into the power tool body; once the voltage drops due to discharge, the battery pack can be removed from the power tool body and recharged using an external charging device.

[0004] In wireless power tools or electrical equipment, there are requirements to ensure specified operating time or output. With the improvement of secondary battery performance, higher output or higher voltage is gradually being achieved. Furthermore, with the development of electrical equipment that uses battery packs as power sources, battery packs of various voltages have been commercialized. Typically, the output voltage of a battery pack is fixed, but Patent Document 1 discloses a power supply device for electrical equipment that arranges multiple battery units within a housing housing. A connecting component allows selection of whether these units are connected in series or in parallel for output, thereby supporting devices with different voltages.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2014-17954 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] For users, preparing multiple battery packs when using multiple electrical devices is cumbersome. There is a desire for easy-to-use battery packs that can switch voltages to accommodate different electrical devices. Furthermore, there is a desire to achieve voltage switching using battery packs that can be easily installed in the electrical device, rather than using a power supply device that is separate from the electrical device, as in Patent Document 1.

[0010] The present invention was made in view of the aforementioned background, and the object of the present invention is to provide a battery pack and an electrical device using the battery pack, the battery pack being able to switch output voltage so that it can be used between electrical devices with different voltages.

[0011] Furthermore, the present invention aims to provide a battery pack that can be installed on the body of an electrical device and can switch the connection state of multiple battery cells.

[0012] Furthermore, the present invention aims to provide a battery pack having a control unit that can monitor the status of multiple battery cells while controlling the discharge or charging of the battery pack.

[0013] Moreover, the purpose of this invention is to provide a battery pack that can stably control the discharge or charging of the battery pack regardless of the connection status of multiple battery cells.

[0014] Another object of the present invention is to provide a battery pack and an electrical device using the battery pack, wherein the battery pack can achieve a balance of current consumption among the multiple cell units contained in the battery pack, which has a switchable high voltage and low voltage output voltage.

[0015] Another object of the present invention is to provide a battery pack in which a microcomputer is provided in any one of the battery cell protection circuits provided for each of a plurality of battery cell units.

[0016] Another object of the present invention is to provide a battery pack that can effectively guide and utilize the capabilities of electrical devices.

[0017] Another object of the present invention is to provide a high-performance battery pack.

[0018] Another object of the present invention is to provide a battery pack having a terminal structure that can be well fitted with the connection terminals on the body side of an electrical device.

[0019] Technical means to solve the problem

[0020] The representative features of the invention disclosed in this application are described below.

[0021] The battery pack of the first invention has the following features.

[0022] A battery pack includes at least first and second cell units as a cell unit composed of multiple battery cells connected in series, and is switchable to a series connection state and a connection state other than the series connection state. The series connection state refers to connecting the first and second cell units in series with each other when the first cell unit is connected to a side with a higher voltage than the second cell unit. The battery pack includes a control unit, which is directly or indirectly connected to the first and second cell units, and is capable of monitoring the state of the battery cells constituting the first cell unit and the state of the battery cells constituting the second cell unit, and outputting a control unit for... The system includes: a control signal for controlling the discharge of the battery pack; a power supply circuit connected to the control unit and capable of supplying power voltage to the control unit; and a housing that houses the first battery cell, the second battery cell, the control unit, and the power supply circuit, and is capable of connecting the battery pack to an electrical device body. The power supply circuit is connected to one of the first and second battery cell units, and the control unit is connected to the power supply circuit and the negative terminal of the one battery cell unit. The power supply circuit generates the power voltage from the voltage input from the one battery cell unit and supplies it to the control unit.

[0023] According to the first invention, a battery pack can be provided that can be installed on an electrical device body and can switch the connection state of multiple battery cells. Furthermore, a battery pack can be provided that includes a control unit capable of monitoring the state of multiple battery cells while controlling the discharge of the battery pack. Moreover, a battery pack can be provided in which the circuit for supplying power voltage to the control unit is closed within a single battery cell, thus enabling stable control of the battery pack's discharge regardless of the connection state of the multiple battery cells.

[0024] The battery pack of the second invention has the following features.

[0025] The battery pack includes: a first protection circuit connected to the first cell unit for monitoring the state of the battery cells constituting the first cell unit; and a second protection circuit connected to the second cell unit for monitoring the state of the battery cells constituting the second cell unit. The control unit is connected to the first and second protection circuits and is capable of monitoring the state of the battery cells constituting the first cell unit via the first protection circuit and monitoring the state of the battery cells constituting the second cell unit via the second protection circuit.

[0026] The battery pack of the third invention has the following features.

[0027] In the battery pack, the second cell unit, which is one of the cell units, is connected to the power circuit, and the power supply voltage is supplied to the control unit from the second cell unit via the power circuit.

[0028] The battery pack of the fourth invention has the following features.

[0029] The battery pack has a signal terminal configured to be connected to the electrical equipment body, and the control signal output from the control unit is output to the electrical equipment body via the signal terminal.

[0030] The battery pack of the fifth invention has the following features.

[0031] In the battery pack, another cell in the first and second cell units is connected to a current consumption control unit, which consumes approximately the same amount of power as the control unit.

[0032] The battery pack of the sixth invention has the following features.

[0033] In the battery pack, when the control unit consumes power, the current consumption control unit also consumes power.

[0034] The battery pack of the seventh invention has the following features.

[0035] The battery pack has a detection unit connected to the control unit, which can detect physical quantities related to the battery pack or the electrical equipment body connected to the battery pack and output the information of the physical quantities to the control unit.

[0036] The battery pack of the eighth invention has the following features.

[0037] The battery pack has a first voltage detection unit as the detection unit. The first voltage detection unit connects another cell unit in the first and second cell units to the control unit. The first voltage detection unit outputs the voltage information of the other cell unit as the physical quantity to the control unit.

[0038] The battery pack of the ninth invention has the following features.

[0039] In the battery pack, the control unit controls the discharge or charging of the battery pack based on whether the battery pack is in the series connection state or in a connection state other than the series connection state.

[0040] The battery pack of the tenth invention has the following features.

[0041] The battery pack has a current detection unit as the detection unit, which is used to detect the current flowing through at least one of the battery cells constituting the first and second battery cell units. The current detection unit outputs the current information flowing through the battery cell as the physical quantity to the control unit.

[0042] The battery pack of the eleventh invention has the following features.

[0043] The battery pack has a temperature detection unit as the detection unit, which is used to detect the temperature of at least one of the battery cells constituting the first and second battery cell units, and outputs the temperature information of the battery cell as the physical quantity to the control unit.

[0044] The battery pack of the twelfth invention has the following features.

[0045] The battery pack has a second voltage detection unit as the detection unit, which is configured to be connected to the terminals of the electrical equipment body. The second voltage detection unit outputs the voltage information input from the terminals of the electrical equipment body as the physical quantity to the control unit.

[0046] The battery pack of the thirteenth invention has the following features.

[0047] In the battery pack, the control unit changes the conditions for overload protection according to the type of electrical equipment body.

[0048] The electrical equipment of the fourteenth invention has the following features.

[0049] An electrical device includes: the battery pack; and at least a first electrical device body as the main body of the electrical device, which can be connected to the battery pack, wherein when the battery pack is connected to the first electrical device body, the battery pack is in a series connection state in which first and second battery cells are connected in series with each other, the second electrical device body has a parallel connection circuit in which the first and second battery cells are connected in parallel with each other, the battery pack is in the parallel connection state when the battery pack is connected to the second electrical device body, and the battery pack is in a non-connected state in which the first and second battery cells are electrically independent of each other when the battery pack is not connected to the first electrical device body.

[0050] The battery pack of the fifteenth invention has the following features.

[0051] A battery pack includes multiple battery cells and is capable of switching between series-connected and parallel-connected outputs of the battery cells. Each battery cell is formed by connecting multiple battery cells in series. A protection circuit for monitoring the state of each battery cell is provided. A microcomputer is included in the protection circuit for the lowest battery cell connected to the ground wire side in the series connection. The microcomputer inputs signals from the multiple protection circuits to monitor the entire battery pack. Furthermore, a power supply circuit is provided to generate power for the microcomputer, which is generated by the output of the lowest battery cell closest to the ground wire side in the series connection. The battery cells are of two types: an upper battery cell (first battery cell) located near the positive terminal in the series connection, and a lower battery cell (second battery cell) located near the negative terminal. When the battery pack is installed in an electrical device, the connection configuration of the upper and lower battery cells is set to either a series connection or a parallel connection.

[0052] According to another feature of the invention, the battery pack has a signal terminal for sending a stop signal (discharge stop signal) to the electrical equipment body. Once the microcomputer detects an abnormal output from any of the multiple protection circuits, it outputs a stop signal to stop the operation of the motor of the connected electrical equipment body. Furthermore, the protection circuit connected to the upper cell unit is a battery protection integrated circuit (IC) that monitors the terminal voltages of each battery cell contained in the upper cell unit. The protection circuit connected to the lower cell unit includes a battery management IC that integrates the functions of the protection circuit IC and the microcomputer on a single chip. Here, an adjustment circuit is provided to balance the total power consumption of the protection circuit (including the microcomputer) in the lower cell unit with the power consumption of the protection circuit in the upper cell unit, thereby making the power consumption of the protection circuit more uniform. The adjustment circuit has a dummy load for consuming power corresponding to the power consumption of the microcomputer, which is provided in the circuit on the upper cell unit side where the microcomputer is not located.

[0053] According to another feature of the invention, the microcomputer has a sleep function that automatically reduces power supply when not in operation. The adjustment circuit includes a circuit that puts the protection circuit on the upper battery cell side into a sleep state when the microcomputer enters sleep mode. Furthermore, the protection circuit has a voltage balance adjustment function that achieves voltage balance across multiple battery cells. In the battery pack, two sets of positive and negative terminals are independently provided. One set of positive and negative terminals is connected to the upper battery cell, and the other set is connected to the lower battery cell. When the battery pack is connected to a high-voltage electrical device, the upper and lower battery cells are connected in series; when the battery pack is connected to a low-voltage electrical device, the upper and lower battery cells are connected in parallel. When the battery pack is not installed in other equipment, the power lines of the upper and lower battery cells are disconnected.

[0054] According to another feature of the present invention, a battery pack switches the output voltage by changing the connection of two battery cells to series or parallel. It includes: a first protection circuit that monitors the state of the battery cell in the first battery cell (which is on the high-voltage side when connected in series); and a second protection circuit that monitors the state of the battery cell in the second battery cell (which is on the low-voltage side when connected in series). Furthermore, a microcomputer monitors the output states of the first and second protection circuits, thereby sending a discharge prohibition signal or a charging prohibition signal to the connected electrical equipment. The power supply for the microcomputer is generated from the output of the second battery cell via a power supply circuit, thus ensuring stable power generation from the battery cell on the side with no change in ground potential, whether in series or parallel connection. Using the battery pack described above, various electrical devices or power tools can be operated.

[0055] According to another feature of the present invention, a battery pack includes a first cell unit and a second cell unit, each composed of multiple cells connected in series. The battery pack can switch between a series connection output and a parallel connection output of the first and second cell units depending on the connected electrical equipment body. A microcomputer is provided to monitor the first and second cell units. The microcomputer determines whether to supply a series connection output or a parallel connection output to the connected electrical equipment body, and changes the overload protection conditions based on the determination result. The overload protection condition is a limit value of the current flowing through the first or second cell unit. Once the microcomputer detects that the limit value is exceeded, it outputs a stop signal to stop the operation of the electrical equipment body.

[0056] According to another feature of the present invention, two positive and two negative terminals are independently provided. One set of positive and negative terminals is connected to a first battery cell, and the other set is connected to a second battery cell. When the battery pack is connected to a high-voltage electrical equipment body, the first and second battery cell units are connected in series. When the battery pack is connected to a low-voltage electrical equipment body, the first and second battery cell units are connected in parallel. A protection circuit for monitoring the state of the battery cell is provided for each battery cell. In the protection circuit provided for any of the multiple battery cell units, a microcomputer is provided to monitor multiple protection circuits. The microcomputer compares the ground potential of the positive terminal of the first battery cell unit located near the positive terminal when the first and second battery cell units are connected in series with the ground potential of the positive terminal of the second battery cell unit, thereby determining whether the output of the battery pack is in a series connection state or a parallel connection state. The current limit value, which serves as an overload protection condition, is switched between when the battery pack is connected to a high-voltage electrical equipment body and when it is connected to a low-voltage electrical equipment body. The current limit when the battery pack is connected to the high-voltage electrical equipment body can be greater than the current limit when the battery pack is connected to the low-voltage electrical equipment body. Alternatively, a current limit when the battery pack is connected to the low-voltage electrical equipment body can be set without setting a current limit when the battery pack is connected to the high-voltage electrical equipment body.

[0057] According to another feature of the invention, the battery pack has an LD terminal (abnormal signal terminal) for outputting a discharge stop signal from a microcomputer. A semiconductor switching element is disposed between the LD terminal and a ground wire. By inputting the discharge stop signal from the microcomputer to the gate signal of the semiconductor switching element, the LD terminal is grounded when the microcomputer issues a discharge stop signal. When the battery pack is not installed in other equipment, the power lines of the first and second battery cells are electrically isolated. Furthermore, the overload protection conditions include either or both of the permissible upper limit temperature of the first and second battery cells and the upper limit voltage value during charging. Once the microcomputer detects that the upper limit value is exceeded, it outputs a discharge stop signal to stop the operation of the electrical equipment body.

[0058] According to another feature of the present invention, protection circuits for monitoring the state of the battery cells are respectively provided in the upper-level battery cell unit and the lower-level battery cell unit. When connected in series, the protection circuit on the lower-level battery cell unit side located on the ground wire side is equipped with a microcomputer. The microcomputer also inputs the signal from the protection circuit on the upper-level battery cell unit side. Thus, by comparing the positive potential of the upper-level battery cell unit with the positive potential of the lower-level battery cell unit, it is determined whether to supply the output of the series connection state or the output of the parallel connection state to the electrical equipment body side, and the overload protection conditions are changed according to the determination result.

[0059] The effects of the invention

[0060] According to the present invention, a battery pack that can be installed on the body of an electrical device and that can switch the connection state of multiple battery cells can be provided. Furthermore, a battery pack including a control unit capable of monitoring the state of multiple battery cells while controlling the discharge or charging of the battery pack can be provided. Moreover, a battery pack capable of stably controlling the discharge or charging of the battery pack regardless of the connection state of the multiple battery cells can be provided.

[0061] Moreover, without relying on a mechanical switching mechanism for switching the output voltage, it can automatically obtain the appropriate output voltage simply by being installed on the electrical equipment itself, thus enabling the battery pack to be shared among electrical equipment with different voltages.

[0062] Furthermore, because each battery cell is equipped with a protection circuit that monitors the status of the battery cell, the balance of the current consumption of each battery cell can be adjusted.

[0063] Furthermore, an adjustment circuit is provided on the upper cell unit side. The adjustment circuit is used to obtain a balance between the total power consumption of the protection circuit including the microcomputer in the lower cell unit and the power consumption of the protection circuit in the upper cell unit, thereby suppressing the deterioration of the voltage balance between cell units.

[0064] Furthermore, since the overload protection conditions can be changed according to the type of electrical equipment, it is possible to realize a battery pack that can effectively guide the performance of electrical equipment. Attached Figure Description

[0065] Figure 1 This is a diagram illustrating the installation of the battery pack of the present invention onto a power tool.

[0066] Figure 2 It means Figure 1 A perspective view of the shape of the battery pack mounting section 10 of the power tool body 1.

[0067] Figure 3 This is a perspective view of a battery pack 100 according to an embodiment of the present invention.

[0068] Figure 4 yes Figure 3 A perspective view of the battery pack 100 with the upper casing 110 removed.

[0069] Figure 5 It means Figure 4 A diagram showing the individual shapes of the power terminals (161 and 171, 162 and 172, 167 and 177). Figure 5 (1) is the overall three-dimensional view. Figure 5(2) is a perspective view of the upper terminal part 200. Figure 5 (3) is a perspective view of the lower terminal part 220.

[0070] Figure 6 This is a perspective view showing the connection state of the power terminals connected to the power tool body. Figure 6 In this context, (1) indicates the state of connection to the power tool body 30 in this embodiment. Figure 6 (2) indicates the state of being connected to the conventional power tool body 1.

[0071] Figure 7 (1) is a perspective view of the contact terminal portion 50 of the power tool body 30 in this embodiment. Figure 7 (2) is a diagram showing the connection status between the contact end 50 and the power terminal of the battery pack 100.

[0072] Figure 8 (1) is a perspective view of the contact end 20 of a conventional power tool body 1. Figure 8 (2) is a diagram showing the connection status between the contact end 20 and the power terminal of the battery pack 100.

[0073] Figure 9 It means Figure 4 A diagram showing the shape of the individual unit of signal terminal component 240. Figure 9 (1) is a three-dimensional view viewed from the left front. Figure 9 (2) is a three-dimensional view viewed from the lower right.

[0074] Figure 10 This diagram shows the fixing status of multiple signal terminal components 240 to the circuit board 150. Figure 10 (1) is a view taken from the front. Figure 10 (2) is a diagram of the signal terminal component 240 viewed from the left. Figure 10 (3) is from Figure 10 The bottom view of (1) is shown below.

[0075] Figure 11 It means Figure 4 A diagram showing the shape of the connection terminal group and the substrate cover 180 arranged around it. Figure 11 (1) is a three-dimensional diagram. Figure 11 (2) is the front view. Figure 11 (3) is Figure 11 A partial enlarged view of the substrate cover 180 in (2) of the image.

[0076] Figure 12 yes Figure 3 A perspective view of the upper shell 110.

[0077] Figure 13 This is a perspective view illustrating a method for applying resin to a circuit board 150.

[0078] Figure 14 This is a diagram illustrating a first modified example of this embodiment. Figure 14 (1) is a perspective view of the upper terminal part 260 and the lower terminal part 280. Figure 14 (2) is the left side view. Figure 14 (3) is the front view.

[0079] Figure 15 This is a diagram showing a second modified example of this embodiment, and is a perspective view showing the upper terminal part 260 and the lower terminal part 280A.

[0080] Figure 16 This is a perspective view showing the upper terminal part 200A and the lower terminal part 220 of the third modified example of this embodiment. Figure 16 Figure (1) shows the state in which they are connected to the body-side terminals of the power tool body 30A. Figure 16 (2) is a diagram showing the state of connection to the body-side terminal of the conventional power tool body 1.

[0081] Figure 17 This is a perspective view showing the upper terminal part 200 and the lower terminal part 220A of the fourth modified example of this embodiment. Figure 17 Figure (1) shows the state in which they are connected to the body-side terminals of the power tool body 30B. Figure 17 (2) is a diagram showing the state of connection to the body-side terminal of the conventional power tool body 1.

[0082] Figure 18 This is a perspective view showing the connection state with the contact end of the power tool body of the fifth modified example of this embodiment.

[0083] Figure 19 This is a circuit diagram showing the state in which the battery pack 100 of this embodiment is connected to the conventional power tool body 1.

[0084] Figure 20 This is a circuit diagram of the battery pack 100 in this embodiment, showing the state of connection to the 18V power tool body 1A with a microcomputer.

[0085] Figure 21 This is a circuit diagram of the battery pack 100 in this embodiment, showing the state of being connected to the 36V power tool body 30.

[0086] Figure 22This is a flowchart representing the control process of battery pack 100.

[0087] Figure 23 This is a diagram illustrating the specific circuit structure of the remaining capacity display component 335 of the battery pack 100 and the upper voltage detection circuit 322.

[0088] Figure 24 Yes Figure 23 Detailed diagram of the input / output circuit of the microcomputer 351.

[0089] Figure 25 It means Figure 23 The table shows the correspondence between the signal levels of input / output ports IO0 to IO3 and the signal level of input port AN1.

[0090] Figure 26 This is a circuit diagram of the battery pack 100A according to the second embodiment of the present invention, which shows the state of connection to a conventional power tool body 1.

[0091] Figure 27 This is a circuit diagram of the battery pack 100A according to the second embodiment of the present invention, and is a diagram showing the state of being connected to the 18V power tool body 1A with a microcomputer.

[0092] Figure 28 This is an exploded perspective view of the battery pack 400 according to the third embodiment of the present invention.

[0093] Figure 29 yes Figure 28 A partial enlarged view of the connection terminals.

[0094] Figure 30 yes Figure 28 Enlarged view of the terminal parts. Figure 30 (1) is a three-dimensional diagram. Figure 30 (2) is a diagram used to illustrate the contact length of the mating part.

[0095] Figure 31 This is a perspective view of a modified example of the third embodiment, showing the terminal part 500.

[0096] Explanation of symbols

[0097] 1. 1A: Power tool body

[0098] 2: Shell

[0099] 3: Handle

[0100] 4: Trigger switch (action switch)

[0101] 5: Motor

[0102] 10: Battery pack installation section

[0103] 11a: Track groove

[0104] 12: Curved section

[0105] 14: Protrusion

[0106] 15: Battery Pack

[0107] 20: Contact end

[0108] 20a: Vertical plane

[0109] 20b: Horizontal plane

[0110] 21: Abutment

[0111] 22: Positive input terminal

[0112] 22a: Terminal section

[0113] 27: Negative input terminal

[0114] 28: LD terminal

[0115] 30: Power tool body

[0116] 30A: Power tool body

[0117] 30B: Power tool body

[0118] 32: Shell

[0119] 33: Handle

[0120] 34: Action Switch

[0121] 35: Motor

[0122] 40: Battery pack installation section

[0123] 45: Motor

[0124] 50: Contact end

[0125] 51: Abutment

[0126] 52: Positive input terminal

[0127] 52a: Terminal section

[0128] 52b: Connecting part

[0129] 52c: Wiring section

[0130] 53: Input / output port group

[0131] 53a: Gap

[0132] 53b: Gap

[0133] 54: Connecting terminal

[0134] 54a: Terminal section

[0135] 54b: Connecting part

[0136] 54c: Wiring section

[0137] 57: Negative input terminal

[0138] 57a: Terminal section

[0139] 57b: Connecting part

[0140] 57c: Wiring section

[0141] 58: LD terminal

[0142] 59: Short circuit strip

[0143] 59a: Connecting part

[0144] 59b, 59c: Terminal section

[0145] 60: Control Department

[0146] 61: Power supply circuit

[0147] 62: Battery voltage detection circuit

[0148] 63: Switch Status Detection Circuit

[0149] 64: Current detection circuit

[0150] 65: Input line

[0151] 72A, 72B: Positive extremes

[0152] 72d: Incision

[0153] 79: Short circuit strip

[0154] 79b: Terminal section

[0155] 79d: Incision

[0156] 82: Positive input terminal

[0157] 82a: Terminal part

[0158] 82b: Connecting part

[0159] 82c: Wiring terminal section

[0160] 87: Negative input terminal

[0161] 87a: Terminal section

[0162] 87c: Wiring terminal section

[0163] 89: Short circuit strip

[0164] 89a: Connecting part

[0165] 89b, 89c: Terminal section

[0166] 100, 100A: Battery pack

[0167] 101: Lower housing

[0168] 101a: Front surface wall

[0169] 101b: Rear surface wall

[0170] 101c: Right lateral wall

[0171] 101d: Left lateral wall

[0172] 103a, 103b: Screw holes

[0173] 104: Slit (Wind Window)

[0174] 110: Upper casing

[0175] 111: Lower section noodles

[0176] 113: Opening

[0177] 114: Step Difference Part

[0178] 115: Upper Noodles

[0179] 115a: convex part

[0180] 120: Narrow slot group configuration area

[0181] 121-128: Slots

[0182] 131: Blocking section

[0183] 132: Elevated part

[0184] 134: Slit (Wind Window)

[0185] 138a, 138b: Tracks

[0186] 141: Lock

[0187] 142a: Locking part

[0188] 142b: Locking part

[0189] 145: Partition

[0190] 146: Upper battery cell unit

[0191] 147: Lower battery cell unit

[0192] 147a: Battery cell

[0193] 148: Battery Cell Unit

[0194] 149: Upper battery cell unit

[0195] 150: Circuit board

[0196] 150a: Surface side

[0197] 150b: Rear side

[0198] 151: Mounting hole

[0199] 153a, 153b: Pads

[0200] 155, 155a: Adhesive resin

[0201] 156a: (Main region for resin inflow)

[0202] 156b: (Sub-region) (for resin inflow)

[0203] 157-159: Wiring patterns

[0204] 161, 162: Top positive end terminal

[0205] 162a, 162b: Arm

[0206] 164: T-terminal

[0207] 165: V terminal

[0208] 166: LS terminal

[0209] 167: Top negative end piece

[0210] 167a, 167b: Arm

[0211] 168: LD terminal

[0212] 171: Lower positive end

[0213] 172: Lower positive end piece

[0214] 172a: Arm

[0215] 177: Lower negative end piece

[0216] 177a, 177b: Arm

[0217] 180: Substrate Cover

[0218] 181: Connecting Part

[0219] 181a: Upper surface

[0220] 181b: Front wall

[0221] 181c: Incision area

[0222] 182: Partition wall

[0223] 182a: Vertical wall portion

[0224] 182b: Horizontal wall section

[0225] 182c: Left end position

[0226] 183: Partition Wall

[0227] 183a: Vertical wall section

[0228] 183b, 183c: Horizontal wall section

[0229] 184: Partition wall

[0230] 184a, 184d: Vertical wall portion

[0231] 184b: Horizontal wall portion

[0232] 184c: Closed plate

[0233] 185: Partition wall

[0234] 187: Partition wall

[0235] 187a: Vertical wall section

[0236] 187b: Horizontal wall section

[0237] 188: Partition Wall

[0238] 188a: Vertical wall section

[0239] 188b: Horizontal wall section

[0240] 190: Switch

[0241] 191: Prism

[0242] 200, 200A: Upper terminal parts

[0243] 201: Base part

[0244] 202: Bridge Section

[0245] 203: Right side view

[0246] 204: Left side

[0247] 203a, 204a: Bending section

[0248] 203b, 204b: convex part

[0249] 203c, 204c: Cutting section

[0250] 205, 206: Arm

[0251] 205a, 206a: Planar part

[0252] 205b, 206b: Bend section

[0253] 205c, 206c: Flat part

[0254] 205d, 206d: Fitting part

[0255] 205e, 206e: Guidance Department

[0256] 205f, 206f: Incision area

[0257] 207, 208: Feet

[0258] 207a, 208a: Cutting section

[0259] 209: Gap

[0260] 211: Gap

[0261] 220, 220A: Lower terminal parts

[0262] 221: Base part

[0263] 222: Bridge section

[0264] 223: Right side view

[0265] 223a: Bending section

[0266] 223c: Cutting section

[0267] 224: Left side view

[0268] 225, 225A, 226: Arm

[0269] 225a, 226a: Planar part

[0270] 225b, 226b: Bend section

[0271] 225c, 226c: Flat section

[0272] 225d, 226d: Fitting part

[0273] 225e, 226e: Guidance Department

[0274] 225f, 226f: Incision area

[0275] 227, 228: Feet

[0276] 227a, 228a: Cutting section

[0277] 231: Incision site

[0278] 240: Signal terminal components

[0279] 241: Base part

[0280] 242: Bridge section

[0281] 243: Right side view

[0282] 243a: Extension

[0283] 243b: Bend

[0284] 243c: Cutting section

[0285] 244: Left side view

[0286] 245, 246: Base of the arm

[0287] 249, 250: Feet

[0288] 249a: Cutting section

[0289] 250a, 250b: Step difference part

[0290] 251-254: Arm

[0291] 256: Solder

[0292] 260: Upper terminal component

[0293] 262: Bridge section

[0294] 263: Right side view

[0295] 263a: Bend

[0296] 264: Left side

[0297] 264b: Dashed line

[0298] 264c: Reinforced surface

[0299] 265, 266: Arm

[0300] 265d: Fitting part

[0301] 267, 268: Feet

[0302] 280, 280A: Lower terminal parts

[0303] 282: Bridge section

[0304] 283: Right side view

[0305] 284: Left side

[0306] 284b: Dashed line

[0307] 284c: Resected portion

[0308] 285, 286: Arm

[0309] 285d: Fitting part

[0310] 291: Incision site

[0311] 300: Protection IC

[0312] 301: Start-up terminal

[0313] 302: Action signal

[0314] 305: Over-discharge signal

[0315] 306: Overcharge signal

[0316] 310: Current consumption control component

[0317] 320: Protection IC

[0318] 321: Power Supply Circuit

[0319] 322, 322A: Upper voltage detection circuit

[0320] 325: Over-discharge signal

[0321] 326: Overcharge signal

[0322] 327: Current Detection Circuit

[0323] 328: LD terminal voltage detection circuit

[0324] 329: Shunt resistor

[0325] 331: Cell temperature detection component

[0326] 335: Remaining capacity display unit

[0327] 341: Discharge Prohibition Signal

[0328] 342: Connecting cable

[0329] 350: Control Department

[0330] 351: Microcomputer

[0331] 352: Input Port Group

[0332] 353: Input / Output Port Group

[0333] 364: Switching Components

[0334] 400: Battery pack

[0335] 401: Lower housing

[0336] 411: Lower section noodles

[0337] 415: Upper Noodles

[0338] 420: Slot

[0339] 432: Elevated portion

[0340] 441: Lock

[0341] 446: Battery cell

[0342] 450: Circuit board

[0343] 461, 462: Top positive end terminal

[0344] 464: T-terminal

[0345] 465: V terminal

[0346] 466: LS terminal

[0347] 467: Top negative end piece

[0348] 468: LD terminal

[0349] 471, 472: Lower positive end terminals

[0350] 474: T-terminal

[0351] 475: V terminal

[0352] 476: LS terminal

[0353] 477: Lower negative end piece

[0354] 478: LD terminal

[0355] 480: Upper terminal component

[0356] 482: Bridge section

[0357] 483: Right side

[0358] 484: Left side

[0359] 485: Arm

[0360] 485a: Planar part

[0361] 485b: Bend

[0362] 485c: Fitting part

[0363] 485d: Guidance section

[0364] 485e: Front end

[0365] 486: Arm

[0366] 486c: Fitting part

[0367] 500: Terminal parts

[0368] 505: Arm

[0369] 506, 507: Arm X-ray

[0370] 508: Grooving

[0371] 509: Arm

[0372] 510, 511: Arm film

[0373] 512: Grooving

[0374] AN1: Input port

[0375] IO0~IO3: Input / output ports

[0376] LD0~LD3: Light Emitting Diodes

[0377] TH1~TH3: Thermistors

[0378] I max (During discharge) Current limit value

[0379] T max Upper limit

[0380] VCC1: Power supply voltage

[0381] VDD1: (Microcomputer) Power Supply Voltage

[0382] VDD2: (Reference voltage for the protection IC)

[0383] V max Upper limit of cell voltage

[0384] V min Cell voltage lower limit Detailed Implementation

[0385] Example 1

[0386] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In the following drawings, the same reference numerals are used for the same parts, and repeated descriptions are omitted. In this specification, an example of an electrical device is a power tool that operates using a battery pack, and the front-back, left-right, and right directions of the power tool's body are defined as follows: Figure 2 The directions shown are based on the installation orientation of the battery pack, and are assumed to be the front-back, left-right, and up-down directions when viewed from the perspective of a single battery pack. Figure 3 The direction shown will be used for explanation. Furthermore, for ease of explanation, the battery pack installation direction will be described based on the condition that the battery pack moves without moving the power tool body.

[0387] Figure 1 This diagram illustrates the installation of the battery pack into the power tool according to this embodiment. As an electrical device, the power tool has a battery pack and uses a motor to provide rotational driving force to drive a front-end tool or working device. Power tools come in various types. Figure 1 The power tool bodies 1 and 30 shown are both referred to as impact tools. The power tool bodies 1 and 30 are tools that perform tightening operations by applying rotational force or axial impact force to the front end of a tool such as a screwdriver bit or socket wrench (not shown). These power tool bodies 1 and 30 include a housing 2 and 32 forming the outer frame, with handle portions 3 and 33 formed on the housing 2 and 32. A trigger-like actuation switch 4 and 34 is provided in a portion of the handle portion 3 and 33, near where the operator's index finger touches when gripping. Below the handle portion 3 and 33, battery pack mounting portions 10 and 40 are formed for mounting battery packs 15 and 100.

[0388] The power tool body 1 is a conventional electrical device that uses a battery pack 15 with a rated voltage of 18V. The battery pack 15 is a conventional battery pack that can be installed into the battery pack mounting section 10 of the 18V-supporting electrical device (power tool body 1) as shown in the combination indicated by arrow a. Inside the battery pack 15, there is only one set of cell units consisting of five 3.6V rated lithium-ion battery cells connected in series, or two sets of such cell units connected in parallel. 18V means a relatively low voltage, and is sometimes referred to here as low voltage. Similarly, the power tool body 1 or electrical device body with a rated voltage of 18V is sometimes referred to as a low-voltage power tool body or a low-voltage electrical device body, respectively. Likewise, the battery pack 15 with a nominal voltage of 18V is sometimes referred to as a low-voltage battery pack.

[0389] The power tool body 30 is an electrical device body with a rated voltage of 36V. As shown by arrow b1, a battery pack 100 capable of outputting 36V is installed in the battery pack mounting section 40. 36V indicates a relatively high voltage, sometimes referred to as high voltage. Similarly, the power tool body 30 or electrical device body with a rated voltage of 36V is sometimes referred to as a high-voltage power tool body or a high-voltage electrical device body, respectively. Inside the battery pack 100, two sets of cell units are housed, each consisting of five 3.6V lithium-ion battery cells connected in series. By changing the connection method of the two sets of cell units, the output can be switched between 18V and 36V. In this embodiment, the battery pack 100 is configured to support dual voltages, enabling both low-voltage and high-voltage outputs. Therefore, the battery pack 100 can be installed in either the 18V-supporting power tool body 1 as shown by arrow b2, or the 36V-supporting power tool body 30 as shown by arrow b1. Thus, the battery pack 100, which enables both low and high voltage outputs, is sometimes referred to here as a voltage-variable battery pack. For the battery pack 100 to be installed on power tool bodies 1 and 30 with different voltages, as indicated by arrows b1 and b2, it is important that the shapes of the rails or terminals of the battery pack mounting sections 10 and 40 are approximately the same, and that the output voltage of the battery pack 100 can be switched. At this point, it is crucial that the output voltage of the battery pack 100 accurately corresponds to the rated voltage of the installed electrical equipment body or power tool body to avoid voltage setting errors (misses).

[0390] Figure 2This is a perspective view showing the shape of the battery pack mounting section 10 of the power tool body 1. The power tool body 1 shown here is an impact screwdriver, with a handle extending downward from the main body of the housing 2, and the battery pack mounting section 10 is formed on the lower side of the handle. A trigger switch 4 (operation switch) is provided on the handle. On the front side of the housing 2, an anvil (not shown) serving as an output shaft is provided, and at the front end of the anvil, a front tool holding section 8 for mounting a front tool 9 is provided. Here, a Phillips head screwdriver is mounted as the front tool 9. Not limited to power tools, in all electrical devices that use battery packs, a battery pack mounting section 10 is formed that corresponds to the shape of the battery pack to be installed, so that battery packs that are not suitable for the battery pack mounting section 10 cannot be installed. In the battery pack mounting section 10, on the inner wall portions of the left and right sides, parallel track grooves 11a and 11b extending in the front-rear direction are formed, and contact ends 20 are provided between them. The contact tip 20 is integrally molded from a non-conductive material such as synthetic resin, and multiple metal terminals, such as a positive input terminal 22, a negative input terminal 27, and an LD terminal (abnormal signal terminal) 28, are cast into it. The contact tip 20 has a vertical surface 20a and a horizontal surface 20b that are contact surfaces in the mounting direction (front-back direction). The horizontal surface 20b is positioned to contact the upper surface 115 (which will be used as the contact surface) when the battery pack 100 is installed. Figure 3 (To be described later) Adjacent to, facing surfaces. On the front side of the horizontal plane 20b, a raised portion 132 is formed that is adjacent to the battery pack 100 (to be described later). Figure 3 (To be described later) The abutting curved portion 12 has a protrusion 14 formed near the center of the left and right sides of the curved portion 12. The protrusion 14 also serves as a screw post for securing the housing of the power tool body 1, which is formed in two parts in the left and right direction, and also functions as a blocking part to restrict the relative movement of the battery pack 100 toward the installation direction.

[0391] Figure 3 This is a perspective view of a battery pack 100 according to an embodiment of the present invention. The battery pack 100 is relative to the battery pack mounting portions 10 and 40 (see reference 1). Figure 1 During installation and removal, the power tool body 1 or 30 automatically switches between low voltage (18V here) and high voltage (36V here) outputs, depending on the shape of the contact terminals. This is in contrast to the conventional 18V rated battery pack 15 (see reference). Figure 1The battery pack 100 has installation compatibility, and the shape of its mounting portion is the same as that of the conventional battery pack 15. The frame of the battery pack 100 is formed by a lower housing 101 and an upper housing 110 that can be divided vertically. The lower housing 101 and the upper housing 110 are made of non-electrical components, such as synthetic resin, and are fixed together by four screws. The upper housing 110 has a mounting mechanism with two tracks 138a and 138b for mounting to the battery pack mounting portion 10. The tracks 138a and 138b extend in a direction parallel to the mounting direction of the battery pack 100 and protrude towards the left and right sides of the upper housing 110. The front ends of the tracks 138a and 138b are open ends, and the rear ends are closed ends that connect to the front wall of the raised portion 132. The tracks 138a and 138b are formed to connect with the track grooves 11a and 11b formed in the battery pack mounting portion 10 of the power tool body 1 (see reference). Figure 2 The corresponding shape, when the tracks 138a, 138b are engaged with the track grooves 11a, 11b, utilizes the locking part 142a (the right-side locking part) which acts as a locking claw. Figure 3 The upper housing 110 and the lower housing 101 are not visible in the image. The locking parts 142a and 142b are engaged to secure the battery pack 100 to the power tool body 1 or 30. When removing the battery pack 100 from the power tool body 1 or 30, the locking parts 141 located on the left and right sides are pressed down. This causes the locking parts 142a and 142b to move inwards, releasing the locking state. Therefore, in this state, the battery pack 100 can be moved in the opposite direction to the installation direction. The upper housing 110 and the lower housing 101 are examples of the "housing" in this invention.

[0392] A flat lower section surface 111 is formed on the front side of the upper housing 110, and an upper section surface 115, which is higher than the lower section surface 111, is formed near the center. The lower section surface 111 and the upper section surface 115 are stepped, and their connection portion is a step portion 114 that forms a vertical surface. The step portion 114 up to the front side of the upper section surface 115 forms a slot group configuration area 120. In the slot group configuration area 120, a plurality of slots 121 to 128 are formed extending from the front step portion 114 to the rear side. The slots 121 to 128 are cut in a manner that has a predetermined length along the battery pack mounting direction. Inside this cut portion, a plurality of connection terminals (to be used as) are provided that can be fitted with the device-side terminals of the power tool body 1, 30 or an external charging device (not shown). Figure 4 (To be described later). The slots 121 to 128 are formed not only on the upper surface parallel to the installation direction but also on the vertical surface, so that the contact end of the power tool body can be inserted from the lower section surface 111 side. Furthermore, an opening 113 with a continuous opening in the horizontal direction is formed on the lower side of the slots 121 to 128 and between them and the lower section surface 111.

[0393] Of the slots 121 to 128, slot 121, located near the right track 138a of the battery pack 100, serves as the insertion port for the positive terminal (C+ terminal) for charging, and slot 122 serves as the insertion port for the positive terminal (+ terminal) for discharging. Furthermore, slot 127, located near the left track 138b of the battery pack 100, serves as the insertion port for the negative terminal (- terminal). In the battery pack 100, the positive and negative terminals are typically arranged far apart. Therefore, viewed from a vertical imaginary plane located at the left and right centers, the positive terminal is located far apart on the right side, and the negative terminal is located far apart on the left side. Between the positive and negative terminals, multiple signal terminals for signal transmission between the battery pack 100 and the power tool body 1, 30 or an external charging device (not shown) are arranged. Here, four slots 123 to 126 for signal terminals are located between the power terminal groups. Slot 123 is a spare terminal insertion port; no terminal is provided in this embodiment. Slot 124 is an insertion port for outputting a signal as identification information of the battery pack 100 to the T terminal of the power tool body or charging device. Slot 125 is an insertion port for inputting a control signal from an external charging device (not shown). Slot 126 is an insertion port for outputting battery temperature information, which is obtained by a thermistor (temperature sensing element) (not shown) that is in contact with the battery cell. To the left of slot 127, which serves as the insertion port for the negative terminal (- terminal), there is further provided a slot 128 for outputting an abnormal stop signal, which is output by the battery protection circuit (described later) included in the battery pack 100.

[0394] A raised portion 132 is formed on the rear side of the upper section surface 115. The raised portion 132 is convex upwards from the upper section surface 115, and a recessed blocking portion 131 is formed near its center. When the battery pack 100 is installed in the battery pack mounting portion 10, the blocking portion 131 becomes a protrusion 14 (see reference). Figure 2 The contact surface of the power tool body 1 is such that when the protrusion 14 on the power tool body 1 is inserted until it abuts against the blocking part 131, the multiple terminals (device-side terminals) disposed on the power tool body 1 and the multiple connection terminals (which will be connected by) disposed on the battery pack 100 are connected. Figure 4 (To be described later) it comes into contact and becomes conductive. Furthermore, the locking portion 142a of the latching portion 141 of the battery pack 100 (the locking portion on the right side)... Figure 3(Not visible in the image) 142b is propelled vertically outward from the lower part of tracks 138a and 138b by the action of a spring, engaging with the not shown recesses in the track grooves 11a and 11b formed in the power tool body 1, thereby preventing the battery pack 100 from falling off. Inside the blocking part 131, a slit 134, connected to the interior of the battery pack 100, serves as a cooling air inlet. Furthermore, when the battery pack 100 is installed in the power tool body 1, the slit 134 is covered and closed in a manner not visible from the outside. The slit 134 is a vent used to force cooling air into the battery pack 100 when the battery pack 100 is connected to a charging device (not shown) for charging. The cooling air introduced into the battery pack 100 is discharged to the outside through the slit 104, which serves as an exhaust vent on the front wall of the lower housing 101.

[0395] Figure 4 yes Figure 3 This is a perspective view of the battery pack 100 with the upper casing 110 removed. Ten battery cells are housed within the interior space of the lower casing 101. Two screw holes 103a and 103b are formed on the front side wall of the lower casing 101 for screwing into the upper casing 110. Screws (not shown) pass through the screw holes 103a and 103b from bottom to top. Although not visible in this view, two screw holes are also formed on the rear side wall of the lower casing 101. Multiple battery cells (not shown) are stacked in pairs of five and secured by separators 145. The separators 145 are made of synthetic resin and are formed with openings only on the left and right sides, which become the ends of the battery cells. Within the separator 145, battery cells are stacked with their axes parallel to each other, and adjacent cells are arranged in alternating opposite directions. The positive and negative terminals of adjacent battery cells are connected by metal connecting tabs (not shown), thus connecting the five battery cells in series. Here, the five series-connected battery cells in the upper section form the upper cell unit 146 (which will be...). Figure 6 (described later), the lower cell unit 147 is formed by five battery cells connected in series on the lower side (to be described in terms of...). Figure 6(To be discussed later). Furthermore, the terms "upper side" and "lower side" for the battery cell unit mentioned here do not refer to the upper or lower section of the battery cell within the lower casing 101. Rather, when two battery cell units are connected in series, the cell unit located on the grounding side is called the "lower battery cell unit," and the cell unit located on the high-voltage side when connected in series is called the "upper battery cell unit." The upper battery cell unit 146 is an example of the "first battery cell unit" in this invention, and the lower battery cell unit 147 is an example of the "second battery cell unit" in this invention. Moreover, the state of connecting the upper battery cell unit 146 and the lower battery cell unit 147 in series is an example of the "series connection state" in this invention.

[0396] The battery cells used are 18650-sized lithium-ion battery cells (not shown), with a diameter of 18mm and a length of 65mm, capable of multiple charge / discharge cycles. In this embodiment, in order to switch the output voltage from the battery pack 100, the series connection voltage (high voltage side output) and parallel connection voltage (low voltage side output) of multiple cell units can be selected. Therefore, according to the idea of ​​this embodiment, as long as the number of cells contained in each cell unit is equal, the number of cell units is arbitrary. However, the number of cell units is set to an even number, such as two or four. The battery cells used are not limited to the 18650 size; they can also be 21700-sized battery cells or other sizes. Moreover, the shape of the battery cells is not limited to cylindrical; they can also be cuboid, laminated, or other shapes. The type of battery cells is not limited to lithium-ion batteries; any type of rechargeable battery, such as nickel-metal hydride battery cells, lithium-ion polymer battery cells, or nickel-cadmium battery cells, can also be used. Two electrodes are provided at both ends along the length of the battery cell. One of the two electrodes is the positive electrode and the other is the negative electrode. However, the position of the electrodes is not limited to the two ends. As long as the cell unit can be easily formed within the battery pack, the electrodes can be configured in any way.

[0397] A circuit board 150 is disposed on the upper side of the separator 145 that holds the battery cell. The circuit board 150 is fixed with multiple connection terminals (161, 162, 164-168, 171, 172, 177) by soldering, and electrical connections are made between the circuit pattern and the connection terminals. Various electronic components (not shown here), such as a battery protection IC or microcomputer, a positive temperature coefficient (PTC) thermistor, resistors, capacitors, fuses, and light-emitting diodes, are then mounted on the circuit board 150. The circuit board 150 is fixed on the upper side of the separator 145, which is made of non-conductive materials such as synthetic resin, in a horizontally extending manner. The material of the circuit board 150 may be a printed circuit board, i.e., a substrate impregnated with a resin that is insulating relative to the raw material, on which patterns and wiring are printed using a conductive material such as copper foil. Single-layer substrates, double-sided substrates, and multi-layer substrates can be used. In this embodiment, a double-sided substrate is used, therefore the circuit board 150 has an upper surface (surface and from...). Figure 4 The upper surface (as seen in the image) and the lower surface (back side). A plurality of connection terminals (161, 162, 164-168, 171, 172, 177) are arranged slightly forward of the center in the front-rear direction of the circuit board 150. Here, the plurality of connection terminals are arranged in a generally horizontal arrangement.

[0398] Each connection terminal, such as Figure 3As shown, on the upper surface of the upper housing 110, arranged sequentially from right to left from the circuit board 150 are C+ terminals (161, 171: positive terminals for charging), + terminals (162, 172: positive terminals for discharging), T terminal 164, V terminal 165, LS terminal 166, - terminals (167, 177: negative terminals), and LD terminal 168. Here, the connection terminal for the power supply line from the battery pack, i.e., the power terminal, comprises two separate terminal parts. That is, the C+ terminal (positive terminal for charging) includes an upper positive terminal 161 and a lower positive terminal 171, and these positive terminal pairs (161, 171) are arranged at positions corresponding to the single slot 121. On the upper side of the inner portion of slot 121, an arm assembly of the upper positive terminal 161 is disposed, and on the lower side of the arm assembly of the upper positive terminal 161, an arm assembly of the lower positive terminal 171 is disposed. Similarly, the upper housing 110 includes an upper positive terminal 162 and a lower positive terminal 172, as indicated by markings on the + terminal (positive terminal for discharge), and these positive terminal pairs (162, 172) are disposed at positions corresponding to a single slot 122. On the upper side of slot 122, an arm assembly of the upper positive terminal 162 is disposed, and on the lower side of the arm assembly of the upper positive terminal 162, an arm assembly of the lower positive terminal 172 is disposed. On the upper housing 110, an upper negative terminal 167 and a lower negative terminal 177, as indicated by markings on the - terminal (negative terminal), are disposed at positions corresponding to a single slot 127. On the upper side of the slot 127 portion, an arm assembly of the upper negative terminal 167 is arranged, and on the lower side of the arm assembly of the upper negative terminal 167, an arm assembly of the lower negative terminal 177 is arranged.

[0399] Connection terminals (161, 162, 164-168) are configured to connect with Figure 3 The positions corresponding to slots 121 to 128 shown. Therefore, they are arranged such that the mating portion connecting the terminals is opened from the circuit board 150 toward the upper and front sides. However, the portion between the upper positive terminal 162 and the T terminal 164 is different from that of the conventional battery pack 1 (see reference). Figure 1 Similarly, this refers to the unused empty space in the battery pack 100 of this embodiment.

[0400] The positive terminal pair (161, 171) for charging is offset forward from the adjacent positive terminal pair (162, 172) for discharging. This is because of space constraints, and the movement range of the locking mechanism (not shown) directly behind the positive terminal pair (161, 171) must be avoided. Therefore, if there were no space constraints, it would be preferable to align the positive terminal pair (161, 171) with the front ends of the positive terminal pair (162, 172) and the negative terminal pair (167, 177).

[0401] The positive terminals (161, 162, 171, 172) and negative terminals (167, 177) are arranged at a considerable distance from each other in the left-right direction. Between them are three signal terminals (T terminal 164, V terminal 165, LS terminal 166). In this embodiment, the signal terminals are provided with two sets of arms extending horizontally, one set on the upper left and one set on the lower left and one set on the lower right. Their detailed shape will be described using... Figure 9 This will be discussed later. Furthermore, regarding the signal terminals (164-166, 168), conventional signal terminal components with a single arm in the vertical direction can be directly used. However, in this embodiment, to ensure consistency with the engagement state of the positive terminals (161, 162, 171, 172) and negative terminals (167, 177) with the device-side terminals, signal terminal components with two arms (hereinafter referred to as...) are also used on the signal terminal side. Figure 9 (To be continued).

[0402] To the left of the negative terminal pair (167, 177), a further signal terminal, namely LD terminal 168, is provided. LD terminal 168 is also formed with two sets of arms, one upper and one lower. However, LD terminal 168 differs in size from the other signal terminals (T terminal 164, V terminal 165, LS terminal 166). This is because, due to space constraints, a locking mechanism (not shown) would reach directly behind LD terminal 168; to avoid this locking mechanism, it is formed smaller than the other signal terminals. All signal terminals (164-166, 168) have their leads extending from the surface through mounting holes 151 formed on the circuit board 150 to the back side, and are fixed on the back side by soldering. In this embodiment, the fixing method of the three signal terminals (164-166) is also characteristic, but its details will be described later. Figure 9 and Figure 10 As will be described later. As mentioned above, after mounting electronic components (not shown) on the circuit board 150 and fixing multiple connection terminals by soldering, the circuit board 150 is fixed to the partition 145 by screwing or bonding.

[0403] Four LEDs (not shown) are provided near the rear of the circuit board 150. Above the LEDs, there are vertically elongated cuboid prisms 191-194. Prisms 191-194 are arranged with their bottom surfaces facing the upward-facing illuminated surfaces of the LEDs (light-emitting diodes, not shown), and their obliquely cut upper surfaces protrude from a slit (not shown) formed in the upper housing 110 to the outside. Prisms 191-194 are provided to diffuse light to illuminate the outside of the upper housing 110. The four LEDs (not shown) are used to display the remaining power of the battery pack 100. When the operator presses switch 190, a number of LEDs corresponding to the voltage of the battery cells light up for a fixed period of time (details will be provided later). Figure 24 , Figure 25 (To be described later). The operating lever (not shown) for operating switch 190 is located on the outer surface of the upper housing 110, which can be operated by an operator. The lower housing 101 is a generally cuboid shape with an opening on the upper surface, including a bottom surface, a front surface wall 101a, a rear surface wall 101b, a right side wall 101c, and a left side wall 101d extending vertically relative to the bottom surface. A slit 104 is provided approximately in the center of the front surface wall 101a. The slit 104 serves as a discharge port for discharging cooling air that has been directed from the charging device side to the internal space of the battery pack 100 during charging using the charging device.

[0404] Next, use Figure 5 To illustrate the shape of the parts (200, 220) used for power terminals. Figure 5(1) is a perspective view showing the individual components of the upper terminal part 200 and the lower terminal part 220. The upper terminal part 200 is a shared component for the upper positive terminals 161, 162 and the upper negative terminal 167, and the lower terminal part 220 is a shared component for the lower positive terminals 171, 172 and the lower negative terminal 177. The upper terminal part 200 and the lower terminal part 220 are formed by cutting a flat plate containing conductive metal through stamping and bending it into a U-shape. The upper terminal part 200 is bent with the bridge portion 202, which forms the bottom of the U-shape, on the upper side, while the lower terminal part 220 is bent with the bridge portion 222 on the rear side. This is because if the bridge portions 202 and 222, formed by bending into a U-shape, are arranged in a manner that intersects at approximately right angles, the front bridge portion 222 cannot adequately ensure the area of ​​the side wall surface in the front-rear direction. Therefore, if the bridge portion is arranged on the upper side, the size of the bridge portion will be smaller. In the lower terminal part 220 of this embodiment, the bridge portion 222 is in the vertical direction, thus shortening the required front-rear length for arrangement and adequately ensuring the size of the bridge portion, especially the length in the vertical direction, thereby improving the rigidity of the lower terminal part 220. On the other hand, in the upper terminal part 200, long arms 205 and 206 that span the lower terminal part 220 can be formed, and a bridge portion 202 is used that extends along the same direction as the front-rear direction of the arms 205 and 206, thereby improving the mounting rigidity of the arms 205 and 206.

[0405] The upper terminal part 200 has a right side 203 and a left side 204 formed in a U-shape and parallel manner, and a bridge portion 202 connecting them and forming the upper surface. Arm portions 205 and 206 are respectively provided on the front side of the right side 203 and the left side 204, which clamp the device-side terminal from the left and right sides inward. They are formed such that they extend in a straight line vertically from the lower side of the front edge of the left side 204 to a position near the upper end, and extend forward in a curve with a large radius of curvature from near the arrow 204d near the upper end. The shape of the right side 203 is symmetrically formed with respect to the left side 204. The arm portion 205 is arranged to extend forward from the upper front edge of the right side 203, and the arm portion 206 is arranged to extend forward from the upper front edge of the left side 204. Thus, the arms 205 and 206 are formed extending from the upper part of the front side of the base 201 towards the front side, that is, in a direction parallel to the mounting direction of the battery pack 100. When viewed from the left and right, the arms 205 and 206 face each other and are stamped to a position close to the minimum spacing, that is, almost touching the fitting portion that engages with the device connection terminal, thereby providing elasticity. Here, stamping refers to plastic processing performed using stamping machinery, where high pressure is used to press raw materials such as metal sheets into a mold, performing cutting, punching, and hole-making shearing processes, and then bending or drawing processes as needed, thereby cutting and shaping into the desired shape. In this embodiment, the upper terminal part 200 and the lower terminal part 220 are formed, for example, using a flat plate with a thickness of approximately 0.5 to 0.8 mm. Therefore, the positive terminals 161, 162, 171, 172 and the negative terminals 167, 177 possess high mechanical strength, resulting in higher engagement pressure when mated with the equipment side terminals. Furthermore, heat treatment or plating can be performed after stamping.

[0406] The lower terminal part 220 is also manufactured in the same manner, having a base portion 221. The base portion 221 includes a right side surface 223 and a left side surface 224 formed in a U-shape and parallel manner, and a bridge portion 222 connecting them. Arm portions 225 and 226 are formed from the vicinity of the elongated upper portion of the right side surface 223 and the left side surface 224 toward the front side. The arms 225 and 226 are designed to clamp the device-side terminal from the left and right sides toward the inward side. The distance S between the upper end position of the upper arm portion group (205, 206) and the lower end position of the lower arm portion group (225, 226) is configured to be approximately equal to the width of the power terminal provided in a conventional 18V battery pack. On the other hand, the upper arm portion group (205, 206) and the lower arm portion group (225, 226) are arranged such that they are separated by a predetermined distance S1 in the vertical direction. Below the lower arm assembly (225, 226), a cutout 231 is formed that is cut wide from the front side. The rear side of the lower terminal part 220 is arranged and fixed in the front-rear direction in such a way that it is separated from the right side 203 and the left side 204 of the upper terminal part 200 by a predetermined gap 211 and does not contact each other.

[0407] Figure 5 (2) is a perspective view of the upper terminal component 200. Here, the area of ​​the bridge portion 202 and the portions of the feet 207 and 208 are marked with shading lines to clearly show their range. The base portion 201 mentioned in this specification refers to the portion exposed from the surface of the mounted circuit board 150 to the upper side, and refers to the portion other than the arms 205 and 206. The base portion 201 of the upper terminal component 200 includes the right side 203, the left side 204 and the bridge portion 202. Feet 207 and 208 are connected to the lower part of the base portion 201. Feet 207 and 208 are inserted into the mounting holes (through holes) of the circuit board 150, so that the feet 207 and 208 protrude from the mounting surface (surface) of the circuit board 150 to the side opposite to the mounting surface (back side). On the back side, the feet 207 and 208 are soldered to the circuit board 150. Furthermore, the arms 205 and 206 are electrically connected to battery cells or electronic components mounted on the circuit board 150 by welding. Here, the height H1 of the feet 207 and 208 is formed to be greater than but less than twice the thickness of the circuit board 150. Moreover, a protrusion 204b protruding rearward is formed on the lower rear portion of the left side panel 204. Although in Figure 5While not visible in the foreground, a similar protrusion is formed on the lower rear portion of the right side panel 203. On the front side of the lower portion of both the right side panel 203 and the left side panel 204, a portion extending convexly in the horizontal direction is formed, forming inwardly bent portions 203a and 204a. Cutting portions 203c, 204c, 207a, and 208a are formed on the upper and lower sides of the bent portions 203a and 204a to facilitate bending. The bent portions 203a and 204a and the protrusions 203b and 204b are formed to contact the upper surface near the mounting holes of the circuit board 150 for vertical positioning of the upper terminal component 200.

[0408] The base portion 201, viewed from the side, is roughly L-shaped and inverted. The rear portions of the arm portions 205 and 206 form flat portions 205a and 206a extending from near the rear connecting portion towards the front, with the right side 203 and left side 204 extending in the same plane. The left-right spacing of the flat portions 205a and 206a is fixed and parallel. In front of the flat portions 205a and 206a, curved portions 205b and 206b are formed, curving inwards when viewed from the left-right direction. In front of the curved portions 205b and 206b, flat portions 205c and 206c are formed again. The opposing flat portions 205c and 206c have a head-narrowing shape, with a wider spacing on the rear side and gradually narrowing towards the front side; they are surfaces extending vertically. The front ends of the planar portions 205c and 206c form fitting portions 205d and 206d that bend outwards with a large radius of curvature R1. The inner curved surfaces of the fitting portions 205d and 206d contact the terminals of the power tool bodies 1 and 30, thereby electrically connecting the upper terminal part 200 to the connection terminals on the power tool bodies 1 and 30. The inner surfaces of the fitting portions 205d and 206d are shaped such that they have a small gap 209 when the battery pack 100 has been removed from the power tool bodies 1 and 30. The front sides of the fitting portions 205d and 206d are connected to guide portions 205e and 206e, which are formed with a rapidly increasing spacing as they face forward, guiding the terminals on the power tool bodies 1 and 30. The inner surfaces of the guide portions 205e and 206e are planar in this case, but could also be curved. The bending portion 205b to the guide portion 205e, and the bending portion 206b to the guide portion 206e, are formed with a fixed vertical height. On the other hand, the flat portions 205a and 206a are formed with downward-facing cutouts 205f and 206f, respectively, whose height decreases as they move towards the rear. The cutouts 205f and 206f are formed for manufacturing reasons: to facilitate bending of the arms 205 and 206 during stamping; and to adjust the clamping load (or clamping pressure) of the set of mating portions 205d and 206d. By forming them in the above manner, an upper terminal part 200 with excellent durability and ease of use can be achieved. In addition, the height of the fitting portions 205d and 206d in the arms 205 and 206 is preferably as large as possible, but the height of the curved portions 205b and 206b, the flat portions 205c and 206c, and the guide portions 205e and 206e in the vertical direction does not necessarily need to be fixed, and can also be formed into a shape that changes with the direction of the front and back.

[0409] Figure 5Figure (3) is a perspective view of the lower terminal part 220. The area of ​​the bridge portion 222 and parts of the feet 227 and 228 are also marked with shading lines to clearly illustrate their range. As can be seen from this figure, the direction in which the lower terminal part 220 bends into a U-shape is different from that of the upper terminal part 200. Here, the base portion 221 is set to a roughly L-shaped form when viewed from the side, with arms 225 and 226 connected to the upper front of the right side surface 223 and the left side surface 224. Planar portions 225a and 226a are formed near the connection between the arms 225 and 226 and the base portion 221. These planar portions 225a and 226a are on the same plane as the right side surface 223 and the left side surface, and the opposing surfaces become parallel. Bent portions 225b and 226b are formed in front of the planar portions 225a and 226a, which bend inwards when viewed from the left and right directions. On the front side of the curved portions 225b and 226b, flat portions 225c and 226c are formed again. The opposing flat portions 225c and 226c have a head-narrowing shape with a wider gap on the rear side and gradually narrowing towards the front side. The front end portions of the flat portions 225c and 226c form fitting portions 225d and 226d that are bent with a large radius of curvature. The inner curved surfaces of the fitting portions 225d and 226d contact the terminals of the power tool bodies 1 and 30, thereby conducting electricity. The inner sides of the fitting portions 225d and 226d are shaped such that they have a small gap when the battery pack 100 has been removed from the power tool bodies 1 and 30. Guide portions 225e and 226e are formed on the front side of the fitting portions 225d and 226d. These guide portions 225e and 226e are formed such that they widen rapidly at intervals as they face forward, and are used to guide the terminals on the power tool body 1 and 30 side. The inner surfaces of the guide portions 225e and 226e can be either planar or curved. The vertical height from the planar portion 225a to the guide portion 225e, and from the planar portion 226a to the guide portion 226e, is fixed. However, similar to the arms 205 and 206 of the upper terminal part 200, the vertical height can vary except for the fitting portions 225d and 226d. By forming them in the above manner, in this embodiment, a lower terminal part 220 with excellent durability and ease of use can be achieved.

[0410] On the lower side of the arm portions 225 and 226 of the lower terminal part 220, a U-shaped cutout 231 is formed from the front side to the rear side (see reference). Figure 5 (1)). The cutout 231 is formed so that the substrate cover 180 can be placed in this part (to be used as a substrate cover). Figure 11(To be described later), the substrate cover 180 is used to divide the upper terminal part 200 and the lower terminal part 220. Legs 227 and 228 are connected to the lower side of the base portion 221. Legs 227 and 228 are inserted into mounting holes in the circuit board 150, protruding from the mounting surface (surface) of the circuit board 150 to the opposite side (back side), and the protruding portions are soldered. Furthermore, soldering establishes an electrical connection from the arms 225 and 226 to the battery cell or electronic component mounted on the circuit board 150. Here, the group of legs 227 and 228 is wired independently so as not to short-circuit with the group of legs 207 and 208 of the upper terminal part 200. The size or shape of legs 227 and 228 is approximately the same as that of legs 207 and 208, and bends 223a and 224a are formed on the front side. Cutting portions 223c, 224c, 227a, and 228a are formed on the upper and lower sides of the bending portions 223a and 224a, but the cutting portions are formed to ensure good bending accuracy during stamping, so the cutting portions are not necessarily needed.

[0411] Next, use Figure 6 This section describes the shape of the contact end 20 on the power tool body 1, 30 side when the battery pack 100 is installed on it, and the connection state with the connection terminals of the battery pack 100. Here, the positive terminal (upper positive terminal 162, lower positive terminal 172) and negative terminal (upper negative terminal 167, lower negative terminal 177) for discharge in the connection terminals of the battery pack 100 are illustrated. LD terminals 28, 58 are further provided at the contact ends 20, 50 of the power tool body 1, 30, but are not shown here. Figure 6Figure (1) shows the state in which the battery pack 100 is installed in the 36V power tool body 30. As mentioned above, ten battery cells are housed inside the battery pack 100, five of which constitute the upper cell unit 146 and the remaining five constitute the lower cell unit 147. Here, the terminal portions 52a and 57a of the positive input terminal 52 and the negative input terminal 57 are smaller than those of the conventional contact end 20 of the power tool body 1. That is, the width in the vertical direction is made smaller so that it only contacts the upper positive terminal 162 and the upper negative terminal 167 disposed on the upper side. The positive side output terminal of the upper cell unit 146 is connected to the upper positive terminal 162, and the negative side output terminal is connected to the lower negative terminal 177. On the other hand, the positive side output terminal of the lower cell unit 147 is connected to the lower positive terminal 172, and the negative side output terminal is connected to the upper negative terminal 167. That is, the positive and negative terminals are each provided in two independent sets. One set of terminals (upper positive terminal 162 and lower negative terminal 177) is connected to the upper cell unit 146, and the other set of terminals (lower positive terminal 172 and upper negative terminal 167) is connected to the lower cell unit 147. Since the upper positive terminal 162 and lower positive terminal 172 are not electrically connected, they are in an electrically independent state when the battery pack 100 is not installed in the electrical device body (the state where the battery pack 100 has been removed). Similarly, the upper negative terminal 167 and lower negative terminal 177 are not electrically connected inside the battery pack 100, and therefore are in an electrically independent state when the battery pack 100 is not installed in the electrical device body (the state where the battery pack 100 has been removed). The electrically independent state of the upper cell unit 146 and the lower cell unit 147 is an example of the "non-connected state" in this invention.

[0412] like Figure 6As shown in (1), the power tool body 30 with a rated voltage of 36V has a positive input terminal 52 and a negative input terminal 57 for receiving power at its contact end. During installation, the positive input terminal 52 is engaged only with the upper positive terminal 162, and the negative input terminal 57 is engaged only with the upper negative terminal 167. On the other hand, the power tool body 30 also has a short-circuit bar 59 at its contact end, which connects the lower positive terminal 172 and the lower negative terminal 177 by short-circuiting. The short-circuit bar 59 is a short-circuit element containing a metal conductive member. One end of the metal member, bent into a U-shape, becomes a terminal portion 59b that engages with the lower positive terminal 172, and the other end becomes a terminal portion 59c that engages with the lower negative terminal 177. The terminal portions 59b and 59c are connected by a connecting portion 59a. The shorting bar 59 is cast together with other device-side terminals such as the positive input terminal 52 or the negative input terminal 57 into a synthetic resin base 51 (which will be used as a base). Figure 7 The short-circuit bar 59 is used only to short-circuit the lower positive terminal 172 and the lower negative terminal 177, so there is no need to wire to the control circuit of the power tool body, etc.

[0413] The positive input terminal 52 is formed by a terminal portion 52a, a wiring portion 52c, and a connecting portion 52b. The terminal portion 52a is the part that fits into the upper positive terminal 162 and is formed in a flat plate shape. The wiring portion 52c is used to solder wires to the circuit board side of the power tool body 30. The connecting portion 52b is the part that connects the terminal portion 52a and the wiring portion 52c and is cast into the synthetic resin base 51. Here, the wiring portion 52c is positioned offset inward from the left-right position of the terminal portion 52a. This is to adjust the spacing of the wiring portions 52c and to stably hold the connecting portion 52b in the base 51 by casting. Furthermore, the left and right corners of the front side of the terminal portion 52a are chamfered at an angle, so that the terminal portion 52a can easily enter between the arm portion 162a and the arm portion 162b. The negative input terminal 57 can use a component shared with the positive input terminal 52. By configuring it to rotate 180 degrees around the vertical axis, it can be used as both a negative input terminal 57 and a positive input terminal 52. Therefore, the negative input terminal 57 is also formed by a terminal portion 57a, a wiring portion 57c, and a connecting portion 57b connecting them. The front corner of the terminal portion 57a ​​(the rear corner when this component is used as the positive input terminal 52) is also chamfered at an angle, so that the terminal portion 57a ​​can easily enter between the arm portion 167a and the arm portion 167b.

[0414] Figure 6In (1), when installing the battery pack 100, when the battery pack 100 is moved relative to the power tool body 30 in the insertion direction, the positive input terminal 52 and the terminal portion 59b pass through the same slot 122 (see reference). Figure 3 The terminals are inserted into the interior and respectively fitted into the upper positive terminal 162 and the lower positive terminal 172. At this time, the positive input terminal 52 is pressed into the arms 162a and 162b of the upper positive terminal 162 in a manner that expands the fitting portion of the upper positive terminal 162. Moreover, the negative input terminal 57 and the terminal portion 59c pass through the same slot 127 (see reference). Figure 3 The terminals 57 are inserted into the interior and respectively fitted into the upper negative terminal 167 and the lower negative terminal 177. At this time, the negative input terminal 57 is pressed into the arms 167a and 167b of the upper negative terminal 167 in a manner that expands the fitting portion of the upper negative terminal 167. Furthermore, the terminals 59b and 59c of the shorting bar 59 are pressed in in a manner that expands the space between the arms 172a and 172b of the lower positive terminal 172 and the lower negative terminal 177, and between the arms 177a and 177b. Moreover, as... Figure 7 As shown in (1), the front corners of the terminal portions 52a, 54a to 58a, 59b, and 59c are beveled at an angle as indicated by arrows 52d, 54d to 59d, and 59e, so that they can be smoothly inserted between the arms of the connecting terminals on the battery pack 100 side.

[0415] The plate thickness of terminal portions 52a, 57a, 59b, and 59c is greater than the initial gap of the mating portion of each arm (the gap when the battery pack 100 is not installed). Therefore, a specified mating pressure is applied to each mating point of terminal portions 52a, 57a, 59b, and 59c with the upper positive terminal 162, upper negative terminal 167, lower positive terminal 172, and lower negative terminal 177. As a result of this connection, the device-side terminals (terminal portions 52a, 57a, 59b, and 59c) of the power tool body 30 and the power terminals (upper positive terminal 162, upper negative terminal 167, lower positive terminal 172, and lower negative terminal 177) of the battery pack make good contact with low contact resistance. Thus, the electrical device body 30 has: a third terminal (52a) inserted into a single slot (122) and connected only to the first terminal (162) of the first and second terminals (162, 172); and a fourth terminal (59b) inserted into a single slot (122) and connected only to the second terminal (172). When the battery pack 100 is connected to the electrical device body 30, within the single slot 122, the first and third terminals (162 and 52a) are connected to each other and both become a first potential, while the second and fourth terminals (172 and 59b) are connected to each other and both become a second potential different from the first potential. The negative terminal pair (167, 177) also becomes in the same connection state, thus enabling... Figure 6 The implementation of connection configuration (1) enables the series connection of the upper cell unit 146 and the lower cell unit 147, resulting in a rated output of 36V from the battery pack 100. The 36V power tool body 30 is an example of the "first electrical equipment body" in this invention. Furthermore, the short-circuit bar 59 of the 36V power tool body 30 is an example of the "series connection circuit" in this invention, and the series connection of the upper cell unit 146 and the lower cell unit 147 is an example of the "series connection state" in this invention.

[0416] On the other hand, when a battery pack 100 is installed in the conventional 18V power tool body 1, it becomes Figure 6The connection relationship is as shown in (2). When the battery pack 100 is installed on the power tool body 1, the positive input terminal 22 is fitted and pressed in such a way that the opening ends of the upper positive terminal 162 and the lower positive terminal 172 are expanded. A portion of the upper part of the positive input terminal 22 contacts the upper positive terminal 162, and a portion of the lower part contacts the lower positive terminal 172. The negative input terminal 27 is similarly fitted. In this way, by simultaneously fitting the arms 162a and 162b of the upper positive terminal 162 and the arms 172a and 172b of the lower positive terminal 172, the positive terminals 162 and 172 are short-circuited, thereby achieving a parallel connection output of the upper battery cell 146 and the lower battery cell 147 to the power tool body 1, that is, an output rated at 18V. The positive input terminal 22 and the negative input terminal 27 contain metal plates of a certain thickness. Therefore, it is important that the engagement pressure of the arms of the upper positive terminal 162 and the upper negative terminal 167 is equal to the engagement pressure of the arms of the lower positive terminal 172 and the lower negative terminal 177. Furthermore, in order to fix their engagement pressure, [the following is omitted as it is not explicitly stated in the original text]. Figure 9 The thickness of the positive input terminal 52, negative input terminal 57, and terminal portions 59b and 59c of the shorting bar 59 of the 36V power tool body 30 shown in (1) is set to be the same as the thickness of the positive input terminal 22 and negative input terminal 27 of the conventional 18V power tool body 1. The 18V power tool body 1 is an example of the "second electrical equipment body" in this invention. Moreover, the positive input terminal 22 and negative input terminal 27 of the 18V power tool body 1 are an example of the "parallel connection circuit" in this invention, and the state of connecting the upper battery cell unit 146 and the lower battery cell unit 147 in parallel is an example of the "parallel connection state" in this invention.

[0417] As described above, the battery pack 100 of this embodiment automatically switches its output by being installed on either the 18V power tool body 1 or the 36V power tool body 30, thus enabling an easy-to-use battery pack 100 that supports multiple voltages. The voltage switching does not occur on the battery pack 100 side, but is automatically performed based on the shape of the contact ends on the power tool body 1 and 30 sides, thus eliminating any risk of voltage setting errors. Furthermore, no dedicated voltage switching mechanism such as a mechanical switch is required on the battery pack 100 side, resulting in a simple structure, low failure rate, and a long-life battery pack. The shorting bar 59, which shorts the lower positive terminal 172 and the lower negative terminal 177, can be installed in the same space as the existing contact ends 20 of the 18V battery pack, thus enabling a voltage-switching battery pack with a size compatible with conventional designs. Furthermore, when charging using an external charging device, the output can be switched via… Figure 6The battery pack 100 is charged using the connection method described in (2) above, therefore there is no need to prepare a charging device for both high-voltage and low-voltage charging. Furthermore, when charging the battery pack 100 using an external charging device (not shown), it can be charged using the same charging device as conventional 18V battery packs. In this case, the contact points of the charging device become... Figure 6 The shape is the same as (2) in the figure, but instead of the positive terminals (162, 172) for discharging, the positive terminals for charging (upper positive terminal 161, lower positive terminal 171) are connected to the positive terminals of the charging device (not shown). The connection is also the same as in the figure. Figure 6 The connection relationship shown in (2) is roughly the same. Thus, by setting the upper cell unit 146 and the lower cell unit 147 to be connected in parallel and charging with an 18V charging device, it is not necessary to prepare a new charging device when charging the battery pack 100 of this embodiment.

[0418] Figure 7 (1) is a perspective view of the contact end 50 of the power tool body 30 in this embodiment. The contact end 50 is, except for Figure 6 In addition to the positive input terminal 52, negative input terminal 57, and shorting bar 59 shown in (1), four metal connecting terminals 54-56 and 58 are cast into a synthetic resin base 51. The shapes of the connecting terminals 54-56 and 58 are such that... Figure 6 In (1), the connecting portions 52b and 57b of the positive input terminal 52 and the negative input terminal 57 are formed in a straight line. Terminal portions 54a-56a and 58a, which fit into the connecting terminals on the battery pack 100 side, are formed on one side. Wiring portions 54c-56c and 58c, which have holes and are used for soldering wires, are formed on the other side, and connecting portions 54b-56b and 58b are formed. The connecting portions 54b-56b and 58b connect the terminal portions and the wiring portions and are cast into synthetic resin. The base 51 securely holds the terminal portions 52a, 54a-56a and 58a by casting the entire upper side and the entire rear side of the terminal portions 52a, 54a-58a. Furthermore, for the terminal portions 54a-56a and 58a, a portion of the rear of the lower side is cast in. Figure 6 In (1), the shape of the short circuit bar 59 is shown, and the connecting part 59a extends in the left-right direction (see reference). Figure 6The terminals 52a and 59b are completely cast into the base 51, with the front portions of the terminals 59b and 59c protruding from the base 51 to the front side. Furthermore, the lower rear side of the exposed portions of the terminals 59b and 59c is cast into the base 51, thereby firmly preventing the terminals 59b and 59c from moving in the left-right direction. In this way, multiple plate-shaped device-side terminals are arranged at the contact end 50. Here, the terminals 52a and 59b are arranged with a fixed gap 53a in the vertical direction. Similarly, the terminals 57a and 59c are arranged with a fixed gap 53b in the vertical direction.

[0419] Figure 7 Figure (2) shows the connection between the contact end 50 and the power terminals (162, 172, 167, 177) of the battery pack 100. The upper positive terminal 162 has two arms 162a and 162b (equivalent to...). Figure 5 (1) Arms 205, 206), the lower positive end 172 has two arms 172a, 172b (equivalent to Figure 5 (1) Arms 225, 226). Arms 162a, 162b of the upper positive terminal 162 are connected in such a way that they are formed as plate-shaped terminal portions 52a by clamping from the left and right. When engaged, arms 162a, 162b bend away from each other in the left and right directions, thereby applying a specified clamping load (fitting pressure) to terminal portions 52a by the restoring force of the spring. As a result, arms 162a, 162b and terminal portions 52a will have good ground contact or line contact, thus achieving good conductivity with very low contact resistance. Similarly, arms 167a, 167b of the upper negative terminal 167 are fitted in such a way that they are formed as plate-shaped terminal portions 57a by clamping from the left and right.

[0420] The arms 172a and 172b of the lower positive terminal 172 are fitted together in a manner that clamps the terminal portion 59b, which is formed in a plate shape from the left and right sides. During this fitting, the arms 172a and 172b bend away from each other in the left and right directions, thereby applying a predetermined clamping load (fitting pressure) to the terminal portion 59b through the restoring force of the spring. As a result, the arms 172a and 172b and the terminal portion 59b will have good ground contact or wire contact, thus eliminating contact resistance and achieving good conductivity. Similarly, the arms 177a and 177b of the lower negative terminal 177 are fitted together in a manner that clamps the terminal portion 59c, which is formed in a plate shape from the left and right sides.

[0421] In this embodiment, it is important to ensure that the connection between terminal 52a and the upper positive terminal 162, and the connection between terminal 59b and the lower positive terminal 172, are in a non-contact state to maintain electrical insulation. Furthermore, it is also important to ensure that the connection between terminal 57a and the upper negative terminal 167, and the connection between terminal 59c and the lower negative terminal 177, are in a non-contact state to maintain electrical insulation. With this configuration, even if the battery pack 100 vibrates at a different resonant frequency than the power tool body 30 due to various vibrations or impacts during power tool use, a short circuit between the upper positive terminal 162 and the lower positive terminal 172 can be prevented, as can a short circuit between the upper negative terminal 167 and the lower negative terminal 177. Additionally, Figure 7 In (2), the diagram of the battery pack side connection terminal that fits into terminal portions 54a-56a and 58a is omitted. However, when the positive side power terminal (upper positive terminal 162 and lower positive terminal 172) and the negative side power terminal (upper negative terminal 167 and lower negative terminal 177) are connected, the signal terminal ( Figure 4 The T terminal 164, V terminal 165, LS terminal 166, and LD terminal 168 shown are also fitted into the terminal portions 54a to 56a and 58a.

[0422] Figure 8 (1) is a perspective view of the contact end 20 of a conventional power tool body 1. Figure 8 Figure (2) shows the connection status with the power terminals of the battery pack 100. The contact end 20 is manufactured by casting six metal terminals 22, 24-28 into a synthetic resin base 21. The shapes of terminals 22, 24-28 are as follows: Figure 6As shown in (2), which represents a portion of terminals 22 and 27 before casting, terminal portions 22a and 24a to 28a that fit into the connection terminals on the battery pack 100 side are formed on one side, wiring portions with holes for soldering wires are formed on the other side, and connecting portions 22c and 24c to 28c are formed. The connecting portions 22c and 24c to 28c connect the terminal portions and the wiring portions and are cast into the synthetic resin of the base 21. The base 21 casts the entire upper side, the entire rear side, and a portion of the rear of the lower side of the terminal portions 22a, 24a to 28a to firmly hold the terminal portions 22a, 24a to 28a. The front corners of the terminal portions 22a, 24a to 28a are beveled as shown by arrows 22d, 24d to 28d to facilitate easy insertion between the arms of the connection terminals on the battery pack 100 side. The contact end 20 has a groove 21b extending in the left-right direction formed on the front side of the base 21, and a groove 21c extending in the left-right direction is also formed on the rear side. These grooves 21b and 21c are held by the housing opening in the contact end 20.

[0423] Figure 8Figure (2) shows the connection between the contact end 20 and the power terminals (162, 172, 167, 177) of the battery pack 100. The signal terminals (T terminal 164, V terminal 165, LS terminal 166, LD terminal 168) on the battery pack 100 side are omitted here. The arms 162a and 162b of the upper positive terminal 162 are engaged with the upper region of the plate-shaped terminal portion 22a, which is formed by clamping from the left and right sides. During this engagement, the arms 162a and 162b bend away from each other in the left and right directions, thereby applying a predetermined clamping load (engagement pressure) to the terminal portion 22a by the restoring force of the spring. Furthermore, the arms 172a and 172b of the lower positive terminal 172 are engaged with the lower portion of the plate-shaped terminal portion 22a, which is formed by clamping from the left and right sides. The upper negative terminal 167 and the lower negative terminal 177, with their respective arms 167a, 167b, 177a, and 177b, are in the same engagement state. Thus, the four arms 162a, 162b, 172a, and 172b contact a terminal portion 22a. Similarly, on the negative side, the arms 167a and 167b of the upper negative terminal 167 are engaged by clamping the upper region of the plate-shaped terminal portion 27a from both sides, and the arms 177a and 177b of the lower negative terminal 177 are engaged by clamping the lower portion of the terminal portion 27a from both sides. In this way, the four arms 162a, 162b, 172a, and 172b contact a terminal portion 22a, and similarly, the four arms 167a, 167b, 177a, and 177b contact a terminal portion 27a. Therefore, they can make good surface or line contact, thereby eliminating contact resistance and achieving good conductivity.

[0424] Next, use Figure 9The shape of the signal terminal part 240 used in the three terminals (164-166) will be described below. The signal terminal part 240 is manufactured by stamping a metal sheet. It consists of a base part 241, which is bent so that the bridge part 242, which is the bottom part of the metal sheet, becomes the rear vertical surface. The arm assembly (arm bases 245, 246) extends forward. The arm base 245 is formed into upper and lower arm assemblies (arms 251, 253). The arm base 246 is formed into upper and lower arm assemblies (252, 254) by forming a groove 244b that extends in the horizontal direction. The metal sheet used for stamping is a flat plate with a thickness of 0.3 mm, which is thinner than the 0.5 mm thickness of the upper terminal part 200 and the lower terminal part 220 used for power terminals. The upper and lower arm assemblies are formed with the same shape, having the same length in the front-to-back direction, width in the vertical direction, and plate thickness. Fitting portions (251d, 253d, etc.) are formed in the upper arm assemblies (arms 251 and 252) and the lower arm assemblies (arms 253 and 254), but the bending shape for these fitting portions is the same both vertically, and the left and right arms are symmetrical. On the other hand, the mounting positions of the feet 249 and 250 are arranged in a manner that is significantly offset in the front-to-back direction. The lower part of the base 241 has different shapes on the left and right sides; the shapes of the right side 243 and the left side 244 are asymmetrical. The foot 249 is positioned significantly forward of the previous foot 250, and the feet 249 and 250 are significantly spaced apart in the front-to-back direction. Thus, the feet 249 and 250 are not arranged adjacently in the left-right direction, but are staggered back-to-back. Therefore, near the lower edge of the right side 243, an extension 243a extending significantly forward is formed, and the feet 249 are formed to extend downward from their front end. The feet 249 and 250 respectively penetrate through through holes (not shown) formed on the circuit board 150 to the back side, and are fixed to the circuit board 150 by soldering the portions protruding to the back side. The upper arm assemblies (arms 251 and 252) and the lower arm assemblies (arms 253 and 254) are electrically connected to electronic components mounted on the circuit board 150.

[0425] Above the foot 249, a bend 243b is formed, which is used to restrict access to the mounting hole 151 (see reference) on the circuit board 150. Figure 4The insertion depth is adjusted and the bend is directed to the left. On the upper and lower sides of the bent portion 243b, semi-circular cut portions 243c and 249a are formed to facilitate bending. For positioning the rear foot 250 towards the circuit board 150, stepped portions 250a and 250b are formed on the front and rear sides of the foot 250. Stepped portion 250a is formed by extending the lower portion of the left side surface 244 forward, and stepped portion 250b is formed using the lower side edge of a bridge portion 242 bent into a U-shape. Thus, stepped portions 250a and 250b abut against the surface of the circuit board 150, thereby determining the vertical mounting position of the foot 250. The front-rear mounting positions of the feet 249 and 250 are determined by the mounting holes 151 of the circuit board 150 (see reference). Figure 4 The location is used to define it.

[0426] Figure 9 Figure (2) shows a view of the signal terminal component 240 from the lower front side. As can be seen from this figure, a horizontally extending groove 245b is formed on the front side of the arm base 245, thereby separating it into upper and lower arm assemblies (arms 251, 253). Moreover, the right foot 249 is arranged to deviate significantly from the left foot 250 towards the front. As a result, even if forces are applied to the four arms 251, 252, 253, 254 in the upward or downward direction, the signal terminal component 240 can be firmly held to the circuit board. When the battery pack 100 is installed on the power tool body 1, 30, the external force applied to the arms 251, 252, 253, 254 is applied in a way that pushes the arm assembly to the rearward side, and this force is in the direction that causes the signal terminal component 240 to fall backward. Conversely, when the battery pack 100 is removed from the power tool body 1, 30, a force pushes the arm assembly forward, causing the signal terminal part 240 to tilt forward. By offsetting the positions of the feet 249, 250 in the front-rear direction, external forces applied during the installation and removal of the battery pack 100 can be effectively blocked, significantly strengthening the mounting rigidity of the signal terminal part 240 and thus improving the durability of the battery pack 100. Furthermore, the arm assembly is also formed in two sections, upper and lower, so even when subjected to various vibrations or external forces during the operation of the power tool, good contact with the terminals on the power tool body side can be maintained through the four contact areas of the arm. On the other hand, the number of mounting holes or solder joints on the circuit board 150 required for manufacturing the signal terminal part 240 remains the same as before, thus suppressing increases in manufacturing costs.

[0427] The signal terminal component 240 of this embodiment not only improves rigidity but also provides other benefits. Conventional signal terminal components (not shown) have two feet electrically / mechanically mounted by soldering to the circuit board. However, these feet are arranged side-by-side in the left-right direction, with a narrow gap between them. Consequently, the soldered parts often connect together, making it difficult to wire signal patterns through the left and right feet. In the battery pack 100 of this embodiment, one foot 249 of the signal terminal component 240 is positioned at the front, and the other foot 250 is positioned at the rear, thus separating the two feet. This widens the distance between the feet of the signal terminal component 240, facilitating multiple wiring or wiring of thick patterns through which the main current flows. This type of signal terminal component 240 is suitable for the battery pack 100 of this embodiment, which aims to achieve higher functionality and promote miniaturization in terms of voltage ratio compared to conventional battery packs. In particular, when the voltage is increased and voltage switching functionality is implemented, the number of electronic components mounted on the circuit board 150 increases. Therefore, it is necessary to optimize the efficiency of the patterned wiring and thicken the wiring through which the main current flows. In this embodiment, a larger substrate than conventionally used is used for the circuit board 150, and electronic components are mounted not only on the rear side of the connection terminal group but also on the front side. At this time, a wiring pattern is also arranged on the underside of the signal terminal component 240. Its arrangement will utilize... Figure 10 To explain.

[0428] Figure 10 This diagram shows the fixing status of multiple signal terminal components 240 to the circuit board 150. Figure 10 (1) is a view from the front. Figure 10 (2) is a view of the signal terminal component 240 from the left. The signal terminal component 240 is a common component, which is arranged and fixed on the circuit board 150 at a distance S4 in the left-right direction as the T terminal 164, V terminal 165, and LS terminal 166. The signal terminal component 240 has a cutout 255 near the center of the arm with a spacing S2 (see figure). Figure 9 Therefore, the upper arm assembly (251, 252) and the lower arm assembly (253, 254) have a two-section shape. When the device-side terminals are not installed, the closest parts (fitting parts) of the upper arm assembly (251, 252) and the lower arm assembly (253, 254) are arranged with a small gap or in contact. Each foot 249, 250 penetrates the mounting hole of the circuit board 150 (see reference). Figure 4 It protrudes to the lower side and is fixed to the lower side (back side) of the circuit board 150 by solder 256.

[0429] exist Figure 10In the side view of (2), the foot 249 located in the front and the foot 250 located in the rear are separated by a distance S3. The distance S3 can be greater than the interval between the feet 249 and 250 (the distance in the left and right direction). By forming a gap like arrow 257, it is easy to arrange a circuit pattern in this gap. Figure 10 (3) is viewed from below. Figure 10 The bottom view of circuit board 150 in (1) is shown. On the back side of circuit board 150, a through hole is formed in the center for soldering signal terminal components 240. Around the through hole, approximately quadrilateral pads 153a-155a and 153b-155b for arranging soldering copper foil are formed. Wiring patterns for connecting from pads 153a-155a and 153b-155b toward the upper battery cell 146 or the lower battery cell 147 are located on the surface side of circuit board 150. Figure 10 The pads 153a-155a for the left foot and the pads 153b-155b for the right foot are arranged in a staggered manner. As a result, multiple patterns 157-159 can be arranged between the pads 153a-155a and the pads 153b-155b as shown in the figure. Here, the wiring patterns 157-159 are shown to be three each, but they can also be a single thick wiring or a combination of other numbers. In this way, by arranging the wiring patterns between the feet 249 and 250 that are staggered in the front and back directions, multiple wiring patterns 157-159 that connect to the rear and front sides of the signal terminals 164-166 can be provided while keeping the spacing between adjacent signal terminals 164 and 165, 165 and 166 the same as before. In addition, as another method to increase the number of wiring patterns that connect to the rear and front sides of the signal terminals 164-166, multiple wiring patterns 157-159 that connect to the rear and front sides of the signal terminals 164-166 can also be provided. Figure 10 The method of cutting portion 243c shown by dashed lines in (2) is as follows. Near the lower edge of the right side panel 243 and in contact with the circuit board 150, an upwardly cut portion 243c, shown by dashed lines, is formed. Thus, the portion indicated by arrow 257 becomes a gap spaced apart from the circuit board 150. Between this gap and the circuit board 150, it is possible to... Figure 10 The wiring patterns 157 to 159 in (3) are similarly configured with circuit patterns. In this way, multiple wiring patterns that connect the rear and front sides of the signal terminals 164 to 166 can be configured not only on the back side 150b of the circuit board, but also on the surface side 150a, thereby improving the execution efficiency of the circuit board 150.

[0430] Figure 11 This diagram shows the shape of the connection terminal group (161-162, 164-168) and the substrate cover 180 arranged around it. Figure 11 (1) is a three-dimensional diagram. Figure 11 (2) is a front view. For the sake of understanding the invention, the circuit board 150 is omitted from the illustration. In the actual product, multiple connection terminal groups (161-162, 164-168, 171, 172, 177) are fixed to the circuit board 150 by welding, and a substrate cover 180 is installed around the connection terminals. The power terminals (161, 162, 167) are formed such that they are higher than the signal terminals (164-166, 168) by a distance H. The substrate cover 180 is made of a molded material of a non-conductor, such as synthetic resin, and covers the area around the feet of adjacent connection terminals. It has a connecting portion 181 on the front side, and multiple partition walls 182, 183, 184-189 are connected to the rear side of the connecting portion 181. The connecting portion 181 has a planar upper surface 181a. The partition walls 182, 183, 184-189 are arranged with the flat portion 181a on the rear side, i.e., the left and right portions of the connecting terminal group, thereby preventing electrical short circuits between the connecting terminals. Furthermore, the upper surface 181a of the connecting portion 181 is flush with the upper section surface 115 of the upper housing 110 (see reference). Figure 3 The components are formed on the same surface, which facilitates relative movement of the contact ends on the body side from the upper section 115 to the connecting portion 181. Furthermore, the substrate cover 180 is provided with a closed area to prevent unused areas from moving. Figure 3 The cover 184 of the opening of the slot 123 makes it difficult for garbage or dust to enter the housing of the battery pack 100 from the slot 123.

[0431] The substrate cover 180 is mainly formed by a connecting portion 181 having a horizontally horizontal upper surface 181a and a plurality of partition walls extending upward therefrom. Partition walls 185, 186, and 189, which are disposed between signal terminals, are walls with a low height H2, and their upper ends are positioned lower than the lower arm of the signal terminals (164-166) or LD terminals 168. In contrast, partition walls 182, 183, 184a, 187, and 188, which are adjacent to power terminals, are walls with a height H3 above the upper surface 181a, and their upper ends are positioned above the upper end of the lower terminal parts and below the arm of the upper terminal parts.

[0432] Power terminals in the connection terminal group, such as those using Figures 5-8As explained, the feet of the upper positive terminals 161, 162 and the lower positive terminals 171, 172 are arranged in a front-to-back direction, and the arm assemblies are arranged in a vertical direction. Similarly, the feet of the upper negative terminal 167 and the lower negative terminal 177 are arranged in a front-to-back direction, and the arm assemblies are arranged in a vertical direction. When the battery pack 100 is installed in an electrical device body rated at 18V, the potential of the arms of the upper positive terminal 162 and the upper negative terminal 167 becomes the same as the potential of the lower positive terminal 172 and the lower negative terminal 177, so there is no problem even if the upper terminal parts come into contact with the lower terminal parts. However, when the battery pack 100 is installed in an electrical device body rated at 36V, the potential of the upper positive terminal 162 and the upper negative terminal 167 is different from the potential of the lower positive terminal 172 and the lower negative terminal 177, so it is important to avoid short circuits caused by contact between the upper and lower arms. Furthermore, a shape that is unlikely to cause short circuits due to the insertion of foreign objects can be adopted. Therefore, in the substrate cover 180 of this embodiment, the partition walls 182, 183, 184a, 187, and 188 in the partition wall portion formed in a manner extending upward from the connecting portion 181 are formed with their upper ends significantly upward, reaching a height H3. Moreover, not only are wall portions extending vertically upward, but also horizontal wall portions extending horizontally from the upper ends of the vertical wall portions are formed.

[0433] Figure 11 (3) is Figure 11 The enlarged view of the substrate cover 180 in (2) is a view other than the diagram of the connecting terminal portion. The partition wall 182 has a vertical wall portion 182a and a horizontal wall portion 182b, and its cross-sectional shape is L-shaped. The horizontal wall portion 182b is shaped such that it extends horizontally from near the upper end of the vertical wall portion 182a into the space between the arms of the adjacent power terminals (upper positive terminal 161, lower positive terminal 171). Moreover, the partition wall 183 has a T-shaped cross-sectional shape and is formed by the vertical wall portion 183a and the horizontal wall portions 183b and 183c extending in two directions from the upper end of the vertical wall portion 183a. The horizontal wall portion 183b extends toward the side close to the adjacent horizontal wall portion 182b, and its front end is set to reach the space between the arms of the upper positive terminal 161 and the lower positive terminal 171. Similarly, the horizontal wall portion 183c extends toward the side closest to the adjacent horizontal wall portion 184b, and is set to extend to the length within the space between the arms of the upper positive terminal 162 and the lower positive terminal 172. The extension of the horizontal wall portions 182b, 183b, and 183c into the space between the arms is described as follows: Figure 11As shown in (2), the positive terminal group can be clearly seen from the front. For example, the right side position of the upper positive terminal 161 is at the same position as the right side position of the lower positive terminal 171. However, the left end position 182c of the horizontal wall portion 182b extends to the left side beyond the left side positions of the upper positive terminal 161 and the lower positive terminal 171, reaching the lower part of the arm portion 161a of the upper positive terminal 161. In addition, the horizontal wall portion 182b is located above the arm portion 171a of the lower positive terminal 171.

[0434] The vertical wall portion 182a and the horizontal wall portion 182b are longer in the front-rear direction than the lower positive terminal 171. Their front ends are positioned approximately at the same location as the front end of the arm portion of the lower positive terminal 171, and their rear ends are positioned further back than the rear end of the lower positive terminal 171. Thus, the vertical wall portion 182a covers the entire right side of the lower positive terminal 171, and also covers the upper portion except for the area near the center on both sides (distance from S5). Furthermore, the vertical wall portion 183a covers the entire left side of the lower positive terminal 171 and the entire right side of the lower positive terminal 172, and also covers the upper portion except for the area near the center on both sides. Here, only the shapes of the vertical wall portion 182a and the horizontal wall portion 182b of the lower positive terminal 171 are mentioned. However, for the lower positive terminal 172, partition walls 183 and 184 are also provided to cover the entire right side and the entire left side, as well as the upper part except for the central part. Therefore, even if an external force is applied to the lower positive terminals 171 and 172, and a force that causes them to bend is applied, they can be effectively held by the substrate cover 180, thereby greatly reducing the risk of accidental short circuit between the lower terminal parts and the upper terminal parts used for power transmission.

[0435] For the negative terminal sides (167, 177), the same considerations apply as for the positive terminal sides (161, 162, 171, 172), with large partition walls 187 and 188 provided on both sides of the negative terminal. Partition wall 187 has the same shape as partition wall 182, formed by a vertical wall portion 187a and a horizontal wall portion 187b, with an L-shaped cross-section. The horizontal wall portion 187b extends from the upper end of the vertical wall portion 187a toward the negative terminal side. Partition wall 188 is formed symmetrically to partition wall 187, and is therefore formed by a vertical wall portion 188a and a horizontal wall portion 188b. The horizontal wall portions 187b and 188b are configured to extend into the space between the arm group of the upper negative terminal 167 and the arm group of the lower negative terminal 177, but with a predetermined interval S5 to avoid obstructing the entry of the equipment-side terminals of the power tool body 1, 30, etc. In this way, the partition walls 187 and 188 are formed in a manner that covers the area around the negative terminals (167, 177) which serve as power terminals. Therefore, even if the upper negative terminal 167 or the lower negative terminal 177 is subjected to strong external pressure and moves (bends) in the front-back direction, the presence of the horizontal wall portions 187b and 188b can significantly reduce the possibility of a short circuit.

[0436] The partition walls 185 and 186 between the signal terminal groups (164-166) have a low height H2 only in the upward direction. This is because only small electrical signals flow through the signal terminal groups (164-166), so the risk of a short circuit is much lower than that on the electrical terminal side. Furthermore, because each of the signal terminal groups (164-166) is a separate component, and the upper and lower arms are at the same potential, the need to worry about a short circuit is low. The same applies to partition wall 189. Partition wall 184 includes vertical wall portions 184a and 184d, which are connected to a sealing plate 184c. The sealing plate 184c is a flat plate extending vertically and laterally, serving to fill the space between the upper positive terminal 162 and the lower positive terminal 172 and the T terminal 164. Figure 3 The internal space of the empty slot 123 is sealed off. Near the upper end of the vertical wall portion 184a, a horizontal wall portion 184b extending toward the positive end side is formed.

[0437] The connecting portion 181 is fixed by connecting to the front surfaces of the vertical wall portions 182a, 183a, 184a, 184d, 185a, 186a, 187a, and 188a located between the connecting terminals. The wall portion of the upper surface 181a of the connecting portion 181 is formed in a state that is floating above the circuit board 150. In the inner portion (lower portion) of the connecting portion 181, a space is formed, and the vertical wall portions 184a, 185a, 186a, and 187a are arranged on the rear side therein. Here, although they are not visible because they are covered by the front wall surface 181b, the vertical wall portions 182a, 183a, 184d, and 188a are also formed in a way that extends downward and contacts the circuit board 150. The inner portion of the connecting portion 181 is also filled with a material that... Figure 13 The circuit board 150 is reinforced by applying a liquid curable resin to its upper surface. Through the curing of the resin, the lower ends of the plurality of vertical wall portions 182a, 183a, 184a, 184d, 185a, 186a, 187a, and 188a are firmly fixed to the circuit board 150. Three cutouts 181c to 181e are formed on the front wall surface 181b of the connecting portion 181. The cutouts 181c to 181e are for... Figure 13 The liquid resin, which will be described later, is evenly distributed across the rear and front portions of the circuit board 150. The viscosity of the liquid resin is relatively low, so the resin flows in the forward and backward direction through the cut portions 181c to 181e (details will be described later).

[0438] Figure 12 It is only extracted Figure 3 The diagram of the upper housing 110 is used to illustrate the shape of the upper section surface 115 of the upper housing 110. Figure 12 (1) is a perspective view of the upper shell 110. Figure 12 (2) is from Figure 12 The arrow diagram shown is based on the direction of arrow B in (1). Figure 12 In (1), the stepped portions are marked with shaded lines to clearly illustrate their extent. For example, using... Figure 11As explained, the power terminals (161, 162, 167) are formed such that they are higher than the signal terminals (164-166, 168) by a distance H in the upward direction. This is because the power terminals are formed from a plate that is thicker than the signal terminals. Therefore, in the conventional shape of the upper surface of the upper housing, the upper ends of the power terminals (161, 162, 167) would interfere with the inner wall of the upper surface. Therefore, in this embodiment, the position of the inner wall surface of the upper surface 115 of the upper housing 110, when viewed in the vertical direction, is partially offset upwards to obtain clearance above the power terminals (161, 162, 167). It is also possible to consider using a recessed portion where only the position of the inner wall surface is recessed upwards, but if the cross-sectional shape of the upper surface 115 is directly used, the thickness of a portion of the upper surface 115 of the upper housing 110 will be insufficient, which may result in a localized decrease in strength. Therefore, in this embodiment, protrusions 115a and 115b protruding outward are formed on the upper part of the outer surface of the upper section 115 near the power terminals (161, 162, 167). By configuring the upper section 115 so that a portion of its wall surface is offset upwards, the internal receiving space can be expanded, and a decrease in wall strength can be prevented. In this embodiment, the protrusion height H4 of the outer wall surface of the upper section 115 is smaller than the recess height H5 of the inner wall surface, thus the size of the protrusions 115a and 115b on the upper section 115 can be kept small, thereby keeping them within a range that allows for unobstructed installation into a conventional power tool body 1. Furthermore, the upper section 115 is not a single surface, but rather forms a step with a localized step, resulting in a higher shaded area. Therefore, compared to a conventional planar upper housing, the strength can be equal to or higher.

[0439] Next, use Figure 13 This describes a method for coating resin onto a circuit board 150. Figure 13This is a perspective view of the circuit board 150. Although the illustration is omitted here, a main region 156a and a sub-region 156b for mounting electronic components are provided on the upper surface of the circuit board 150. The main region 156a is located rearward from the connection terminal group, and a protection management IC containing a microcomputer (described later) is mounted here. The sub-region 156b is the region in front of the connection terminal group. Here, a curable resin is used to cover the entire mounted electronic components. The curable resin is cured from a liquid state, for example, urethane resin can be used. In order to evenly distribute the liquid urethane resin across the upper surface of the circuit board 150, an adhesive resin 155 is first applied to the outer edge of the component group mounted on the circuit board 150. The adhesive resin 155 acts as a dam to prevent the liquid resin from flowing out. The adhesive resin 155 is, for example, an adhesive that is drawn cylindrically from a tubular container through a small outlet and continuously adheres along the outer edge of the area where urethane resin is to be distributed. At this point, it is important to apply the adhesive seamlessly along the outer edge, with one end and the other end forming a contact with the substrate cover 180. In this way, the adhesive resin 155, which serves as the outer frame, is attached to approximately one circumference of the outer edge where the resin is to flow, and then the urethane resin in a liquid state flows into the inner side of the upper surface of the circuit board 150.

[0440] The amount of urethane resin flowing in is set to fully fill the area surrounded by the adhesive resin 155. At this time, in areas where resin coverage is not desired, the outer edges of these areas are surrounded by adhesive resin 155a-155c to prevent resin flowing outside these areas from reaching the area surrounded by adhesive resin 155a-155c. Furthermore, as long as the location of the urethane resin inflow is near the main region as indicated by arrow 156a, the resin will not flow into the area surrounded by adhesive resin 155a. Moreover, with the wall surface of the connecting portion 181 forming the upper surface 181a of the substrate cover 180 floating, the rear side wall of its lower portion is open, and the front side becomes a wall surface. By forming cutouts 181c-181e in this portion, resin can flow well from the main region 156a into the sub-region 156b. In this way, by covering the entire component mounting surface of the circuit board 150 with resin and then allowing it to cure, the surface of the circuit board 150 is uniformly and seamlessly covered with resin, thus protecting the mounted electronic components from water or dust. Furthermore, when using a double-sided substrate as the circuit board 150, the same process can be used to cover the back side with resin. Moreover, for areas not filled with adhesive resin 155, such as near screw holes or soldered wires, resin can be applied after screw tightening or after soldering.

[0441] The above uses Figures 1 to 13 The first embodiment of the present invention has been described, but the battery pack 100 shown in the first embodiment can be modified in various ways. Figure 14 This is a diagram showing the shapes of the upper terminal part 260 and the lower terminal part 280 in the first modified example of this embodiment. Figure 14 (1) is a three-dimensional diagram. Figure 14 (2) is the left side view. Figure 14 (3) is a front view. Similar to the first embodiment, the upper terminal part 260 and the lower terminal part 280 each have two arm assemblies (265 and 266, 285 and 286) in the left-right direction, and the two arm assemblies are arranged in the up-down direction. Similar to the first embodiment, the foot assemblies (267, 268) of the upper terminal part 260 are configured to be parallel to the foot assemblies (287, 288) of the lower terminal part 280 in the front-back direction. On the lower portion behind the right side surfaces 263, 283 and the left side surfaces 264, 284, as shown... Figure 14 In (2), as indicated by arrows 262a and 282a, bridge portions 262 and 282 protrude in a rearward-curving manner. Therefore, these protruding portions are used for vertical positioning when the upper terminal part 260 and the lower terminal part 280 are mounted onto the circuit board 150. At the upper front of the feet 267 and 268, 287 and 288, bent portions 263a, 264a, 283a, and 284a are formed, causing the convexly extending portion to bend inward (but...). Figure 14 263a) is not visible in the image, but their shapes are similar to... Figure 5 The structure of the first embodiment shown is the same.

[0442] The direction of the U-shaped bend of the upper terminal part 260 is the same as... Figure 5 The directions shown are different. Here, the portion that becomes the bottom when bent in a U-shape, namely the bridge portion 262, is formed in a vertical manner. Regarding the bending shape of the lower terminal part 280, the U-shaped bending direction is different from... Figure 5 Similar to the lower terminal part 220 shown, the bridge portion 282 is vertical. Bridge portions 262 and 282 are arranged parallel to each other with a substantially fixed interval in the front-to-back direction, and they are arranged to extend substantially vertically relative to the surface of the circuit board 150. Similar to the first embodiment, the upper terminal part 260 and the lower terminal part 280 are manufactured by stamping a metal plate, but this plate is thicker.

[0443] The right side 263 and left side 264 are roughly rectangular, extending vertically. Near the upper part, arms 265 and 266 extend forward. Near the rear root of arms 265 and 266, i.e., near chain line B2, their width (vertical length) is large, gradually decreasing towards the front, becoming fixed further forward than the imaginary line B1. In the fitting portions 265d and 266d, when viewed from above, they are curved inwards into a surface with a predetermined radius of curvature R1, which is consistent with... Figure 5 The same applies to the first embodiment shown. In this way, the arms 265 and 266 are formed in such a way that they extend forward from the upper front part of the U-shaped base portion, and the arms 265 and 266 are formed in such a way that they are elastic in a state where they do not contact each other.

[0444] The lower terminal part 280 has a right side 283 and a left side 284 formed in a U-shape and parallel manner, and a bridge portion 282 connecting them. Arm portions 285 and 286 are provided from the slender upper portions of the right side 283 and the left side 284, extending forward and obliquely upward. The width of the arms 285 and 286 in the vertical direction is approximately fixed in the front-rear direction. They are formed in a horizontal direction on the side forward of the imaginary line B1, but are arranged obliquely on the side rear of the imaginary line B1. Below the arm group (285, 286) of the lower terminal part 280, a cut-out portion 291 is formed from the front side. As a result of this arrangement, the length (front-rear length and forward of B2) of the arms 265 and 266 of the upper terminal part 260 is longer than the length (front-rear length and forward of arrow 291). For arm assemblies with different lengths in the front-to-back direction, it is preferable to make the engagement pressure of the upper terminal part 260 the same as that of the lower terminal part 280. This is because if the engagement pressure is not made equal, the contact resistance with the flat device-side terminals on the power tool body 1 or 30 will change, which may result in slight differences in heat generation or different wear conditions due to long-term use. In this modified example, in order to achieve a balance between the engagement pressures of the upper terminal part 260 and the lower terminal part 280, the initial gap spacing of the battery pack in the non-installed state is different. That is, when the battery pack 100 is not installed on the power tool body 1 or 30 (disassembled state), the minimum spacing between the left and right arm parts 265 and 266 is different from the spacing between the arm parts 285 and 286. Here, the distance between the arms 265 and 266 of the upper terminal part 260 is 0.2 mm, and in contrast, the minimum distance between the arms 285 and 286 of the lower terminal part 280 is 0.5 mm.

[0445] To ensure uniform engagement pressure, the shapes of the upper terminal part 260 and the lower terminal part 280 were carefully designed. That is, as... Figure 14 As shown in (2), the upper terminal part 260 should originally have an approximately right-angled interior angle like the dashed line 264b. However, here, it is shaped such that the outline of the dashed line 264b extends in the direction of arrow 264e, and a reinforcing surface 264c, which is a right-angled triangle in side view, is added. As a result, the outline of the interior angle portion becomes inclined as shown by arrow 264d, and the mounting rigidity of the arms 265 and 266 of the upper terminal part is improved by changing its shape. In conjunction with the shape change of the interior angle portion of the upper terminal part 260, the shape of the exterior angle portion of the lower terminal part 280 is cut off from the portion of the dashed line 284b in the direction of arrow 284e, thereby becoming a shape with a cut-off portion 284c that is a right-angled triangle in side view. As a result, the outline of the exterior angle portion becomes like arrow 284d, and the rigidity of the arms 285 and 286 of the lower terminal part decreases. For the contour portions indicated by arrows 264d and 284d, their contours are determined such that they are spaced apart at a certain interval, making them approximately parallel to each other when viewed from the side. Furthermore, if the cut-off portion 284c is formed, the vertical length of the bridge portion 282 will be shortened. However, since the lower terminal part 280 is small, it is sufficiently strong compared to the upper terminal part 260, thus achieving a balance in strength through their shape changes. In this way, for the upper terminal part 260, the shape of the inner corner portion is changed by adding a reinforcing surface 264c; for the lower terminal part 280, the shape of the outer corner portion is changed by adjusting the strength through the formation of the cut-off portion 284c. This achieves a balance in strength, making the engagement pressure of the arms 265 and 266, and 285 and 286 on the body-side terminals approximately equal.

[0446] Figure 14 (3) is a frontal view of the upper terminal part 260 and the lower terminal part 280. The vertical height or mounting position of the arms 265 and 266, and the vertical height or mounting position of the arms 285 and 286, are compared with... Figure 5 In the first embodiment shown, the upper terminal part 200 and the lower terminal part 220 have the same shape and the same positional relationship. However, the metal sheet used in this modified example has a different thickness, and is made of a different material than... Figure 5The terminal parts of the first embodiment shown are manufactured using thick sheet metal. Furthermore, in the non-installed state of the battery pack 100, the minimum spacing between the upper and lower arm assemblies differs. Specifically, the spacing between the lower arm 285 and 286 in the left-right direction is larger than the spacing between the upper arm 265 and 266. This spacing is inversely proportional to the length of the upper and lower arm 265 and 266 in the mounting direction (front-back direction). The longer arm 265 and 266 initially face each other with a narrow spacing. Conversely, the shorter arm 285 and 286 face each other with a wide spacing.

[0447] As described above, in the first modification, upper terminal part 260 and lower terminal part 280 with a plate thickness of 0.8 mm are used as power terminals. Regarding the signal terminal parts, since only a small current flows through them, they can be manufactured using a metal plate with a thickness of approximately 0.3 mm, similar to the conventional battery pack 15. In this modification, the rigidity of the power terminals through which a large current flows is further improved, ensuring a good engagement not only during operation but also after long-term use. Furthermore, to ensure that the engagement pressure of the upper and lower arm assemblies is approximately the same, it is not limited to adjusting the gap of the engagement portion and changing the shape near the mounting root; other modifications, especially adjustments to the plate thickness and selection of materials for the terminal parts, can also achieve this.

[0448] Figure 15 This is a perspective view showing the upper terminal part 260 and the lower terminal part 280A in a second modified example of this embodiment. In the second modified example, relative to... Figure 14 In the first modified example shown, the upper terminal part 260 is the same, but the plate thickness of the lower terminal part 280A differs from the initial spacing of the arm. That is, the plate thickness of the lower terminal part 280A is changed from... Figure 14 The lower terminal part 280 shown is thinned from 0.8 mm to 0.6 mm, and the spacing between the mating portions 285d and 286d is changed from... Figure 14The lower terminal part 280 shown is narrowed from 0.5mm to 0.2mm. The spacing between the mating portions 265d and 266d of the upper terminal part 260 is also 0.2mm, the same as in the first modified example. By adjusting the plate thickness and spacing of the elastic arms 285 and 286 in this way, the mating pressure of the mating portions 265d and 266d of the upper terminal part 260 can be approximately equal. Here, the mating portions 265d and 266d are shaped as semi-cylindrical surfaces, with the central axis of the cylindrical surface located in the vertical direction, and the inner wall surfaces of the mating portions 265d and 266d are cylindrical surfaces with a radius of curvature of R1. The inner wall surfaces of the mating portions 285d and 286d of the lower terminal part 280A are also formed as cylindrical surfaces with a radius of curvature of R1. The cylindrical shapes of the mating surfaces of these mating portions 265d and 266d, as well as mating portions 285d and 286d, are preferably formed with equal radii of curvature R1, so that the size or shape of the linear or rectangular contact portions is approximately the same. By making the size of the contact portions or contact areas uniform in this way, the clamping pressure (mating pressure) becomes approximately equal, and the contact resistance is also approximately the same, which is therefore preferable.

[0449] Figure 16 This is a perspective view showing the upper terminal part 200A and the lower terminal part 220 of the third modified example of this embodiment. Figure 16 Figure (1) shows the state in which they are connected to the body-side terminals of the power tool body 30A rated at 36V. In the third variation, only the shape of the upper terminal part 200A, especially the shape of the arms 205A and 206A, differs from the first embodiment, while the structure of the base and foot of the upper terminal part 200A is the same as in the first embodiment. The upper terminal part 200A is used as the upper positive terminal 161, 162 and the upper negative terminal 167. The upper terminal part 200A causes the arms 205A and 206A to extend significantly forward, and the position of the mating portion of the upper arms 205A and 206A is forward than the position of the mating portion of the lower arms 225, 226. The shape of the opposing mating portions is a semi-cylindrical surface with equal radius of curvature R1, and the shape of the mating portion of the arms 205A and 206A is the same as the shape of the mating portion of the arms 225, 226. With the arms 205A and 206A extended, the positive terminal 72A of the 36V side power tool body is also shorter than before, corresponding to the change in shape. The size or thickness of the shorting bar 79, which serves as a shorting component, is also... Figure 6The shorting bar 59 shown is the same. However, a semi-circular cut 79d is formed on the upper part of the terminal portion 79b of the shorting bar 79. The cut 79d is to prevent the terminal portion 79b from contacting the upper arm portions 205A and 206A in the event that the positive terminal 72A of the device side terminal and the terminal portion 79b move relative to each other in an arc shape as shown by arrow 45a or in the horizontal direction due to some reason. Since the cut 79d is formed on the terminal portion 79b of the shorting bar 79, the possibility of short circuit between the upper terminal part 200A and the lower terminal part 220 can be greatly reduced when the power tool is operated after the battery pack 100 is installed, even if there is a relative positional deviation caused by the difference in the resonant frequency between the power tool body 30A and the battery pack 100.

[0450] Figure 16 Figure (2) shows the connection state with the body-side terminals of a conventional power tool body 1. When installed on the side of a power tool body 1 rated at 18V, the two sets of arms 205A, 206A and arms 225, 226 are fitted into the positive input terminal 22. At this time, the contact position of the fitting portion of arms 205A, 206A with the positive input terminal 22 is forward-biased compared to the contact position of the fitting portion of arms 225, 226 with the positive input terminal 22. However, since the thickness of the positive input terminal 22, including the vicinity of each contact position, is uniform, a good conductive state can be achieved as long as the size of the contact portion or contact area formed by arms 205A, 206A is equal to the size of the contact portion or contact area formed by the fitting portion of arms 225, 226, so the movement of the contact position will not cause any problems.

[0451] Figure 17 This is a perspective view showing the upper terminal part 200 and the lower terminal part 220A of the fourth modified example of this embodiment. Figure 17 Figure (1) shows the state in which they are connected to the body-side terminals of the power tool body 30B. In the fourth variation, only the shape of the arms 225A and 226A of the lower terminal parts 220A is different from that of the first embodiment; the other structures are the same as those of the first embodiment. Here, the arms 225A and 226A extend forward, and the position of the mating portion of the lower arms 225A and 226A is forward compared to the position of the mating portion of the upper arms 205 and 206. Correspondingly, the rear end of the shorting bar 79 is also forward compared to the past. Furthermore, a semi-circular cutout 72d is formed at the lower part of the positive terminal 72B. The cutout 72d is provided to significantly reduce the possibility of the positive terminal 72B contacting the arms 225A and 226A in the event that the positive terminal 72B and the terminal part 79b of the device side terminal move along arrow 45b for some reason.

[0452] Figure 17 Figure (2) shows the connection state with the body-side terminals of the conventional power tool body 1. Two sets of arms 205, 206 and arms 225A, 226A are fitted into the positive input terminal 22 on the side of the power tool body 1. Here, the positions of the contact portions formed by arms 205, 206 and the contact portions formed by arms 225A, 226A are separated by a distance L in the front-rear direction. However, the size of the contact portions or contact areas formed by arms 205, 206 and the size of the contact portions or contact areas formed by the fitting portions of arms 225A, 226A become equal, thus enabling a good conductive state to be achieved in the same way as in the first embodiment.

[0453] Figure 18 This is a perspective view showing the shape of the contact end on the power tool body 30A side of the fifth modification of this embodiment. In the fifth modification, the positions of the positive and negative terminals of the first embodiment are reversed vertically compared to the position of the shorting bar. Here, the upper positive terminal 162 and the upper negative terminal 167 are short-circuited by the shorting bar 89. The shorting bar 89 can be used with the shorting bar 59 of the first embodiment (see reference 59). Figure 6 The same parts can be cast into the synthetic resin base of the contact end of the power tool body. The positive input terminal 82 includes a terminal part 82a, a connecting part 82b, and a wiring terminal part 82c, which is the same as the positive input terminal 52 of the first embodiment (see reference 82). Figure 6 Similarly, the wiring terminal 82c is located on the rear surface instead of the upper surface of the contact end, thus changing the shape of the connecting part 82b and the wiring terminal 82c. Likewise, the position of the wiring terminal 87c in the negative input terminal 87 is also different. Corresponding to the offsetting of the positions of the positive input terminal 82 and the negative input terminal 87 in the contact end, the connection state between the upper battery cell 146 and the lower battery cell 147 is also changed. That is, the upper battery cell 146 is connected to the lower positive terminal 172 and the upper negative terminal 167, and the lower battery cell 147 is connected to the upper positive terminal 162 and the lower negative terminal 177.

[0454] Even by changing the position of the short-circuit bar 89 as described above, the battery pack with an automatic voltage switching mechanism of this embodiment can still be realized. By adopting this structure, the mounting positions of the wiring terminals 82c and 87c are not led out to the upper side of the contact end (see reference...). Figure 7The contact points on the power tool body can be extended to the rear, thus increasing the design freedom of the contact ends. Furthermore, the function of the short-circuit bar 89 can be achieved simply by having terminal portions 89b and 89c and short-circuiting them. Therefore, it is not necessary to connect the connecting portion 89a using a metal plate; it can be achieved by using conductive components to form an electrical connection, such as connecting with a wire, connecting with a fuse element, or any other arbitrary method.

[0455] Figure 19 This is a circuit diagram showing the state in which the battery pack 100 of this embodiment is connected to a conventional power tool body 1. The conventional power tool body 1 is configured to include a positive input terminal 22, a negative input terminal 27, and an LD terminal 28 on the device side. A trigger switch 4 and a DC motor 5 are connected between the positive input terminal 22 and the negative input terminal 27. A semiconductor-formed switching element M101 is provided between the motor 5 and the negative input terminal 27. The drain-source of the switching element M101 is connected to the power supply path of the motor 5, and its gate is connected to the positive input terminal 22 via a resistor R101. Furthermore, the gate of the switching element M101 is connected to the LD terminal 28 via a resistor R102. Normally, the LD terminal 28 on the battery pack 100 side is in a high impedance state. At this time, a positive voltage is applied to the gate of the switching element M101 via the resistor R101, and the switching element M101 is in a conducting state. At this time, if the LD terminal 168 is caused to drop to ground potential from the battery pack 100 side via the discharge inhibit signal 341, the gate potential of the switching element M101 becomes a voltage that divides the voltage of the positive input terminal 22 using resistors R101 and R102. This divided voltage becomes a potential that blocks the source-drain connection of the switching element M101. As a result, the power supply path to the motor 5 is blocked, and therefore the rotation of the motor 5 stops. The potential switching of the LD terminal 168 is controlled by the control unit 350 on the battery pack 100 side, and is performed when the voltage of the battery cell drops to a specified value, in a so-called over-discharge state, or when the current flowing through the battery cell exceeds a specified upper limit value, or when the temperature of the battery cell exceeds an upper limit value, etc. The discharge inhibit signal 341 is an example of a "control signal" in this invention, and the LD terminal 168 is an example of a "signal terminal" in this invention.

[0456] Battery pack 100 Figure 4As shown, the battery pack 100 is configured with an upper positive terminal (upper +) 162, a lower positive terminal (lower +) 172, an upper negative terminal (upper -) 167, and a lower negative terminal (lower -) 177. Furthermore, it includes an LD terminal 168 as a signal terminal. In addition to these terminals, the battery pack 100 also includes other signal terminal groups (T terminal 164, V terminal 165, LS terminal 166), but these are not shown in the diagram here. The output of the upper cell unit 146 is connected to the upper positive terminal 162 and the lower negative terminal 177. Specifically, the positive terminal (+ output) of the upper cell unit 146 is connected to the upper positive terminal 162, and the negative terminal (- output) of the upper cell unit 146 is connected to the lower negative terminal 177. Similarly, the positive terminal (+ output) of the lower cell unit 147 is connected to the lower positive terminal 172, and the negative terminal (- output) of the lower cell unit 147 is connected to the upper negative terminal 167.

[0457] The upper cell unit 146 and the lower cell unit 147 are composed of five lithium-ion battery cells connected in series. A protection IC 300, a protection IC 320, and a control unit 350 for monitoring the voltage of the battery cells are connected to the upper cell unit 146 and the lower cell unit 147. The protection IC 300, by inputting the voltage across each battery cell in the upper cell unit 146, performs overcharge protection, over-discharge protection, cell balancing, cascade connection, and disconnection detection functions. The protection IC 300 is a commercially available integrated circuit as a "protection IC for lithium-ion batteries." The protection IC 300 has a built-in power supply circuit, which obtains its operating power from the voltage of the upper cell unit 146. Furthermore, when the voltage of the battery cell in the upper battery cell unit 146 drops below a predetermined value and becomes over-discharged, the protection IC 300 outputs an over-discharge signal (high signal) 305 to the control unit 350. When the voltage of the battery cell in the upper battery cell unit 146 reaches a predetermined value or higher during charging and becomes over-charged, the protection IC 300 outputs an over-charge signal (high signal) 306 to the control unit 350.

[0458] Protection IC 320 is connected to the lower cell unit 147. Here, in the circuit of the lower cell unit 147, specifically in the circuit between the lower positive terminal 172 and the upper negative terminal 167, a control unit 350 is also provided. That is, the protection circuit connected in parallel with the upper cell unit 146 only includes protection IC 300, while the protection circuit connected in parallel with the lower cell unit 147 includes both protection IC 320 and control unit 350. Control unit 350 includes a microcontroller unit (MCU) (a so-called "microcomputer"). Control unit 350 receives inputs from the outputs of protection IC 300 (over-discharge signal 305, over-charge signal 306), the outputs of protection IC 320 (over-discharge signal 325, over-charge signal 326), and signals from the cell temperature detection component 331. The microcomputer in the control unit 350 includes, for example, a voltage detection circuit called an Analog Front End (AFE), which measures the current flowing through the lower cell unit 147 based on the output voltage of the current detection circuit 327. The power supply for driving the control unit 350 is generated by a power supply circuit 321 connected to the lower cell unit 147, and the power supply voltage (VDD1) is supplied to the control unit 350. The protection IC 300, protection IC 320, and control unit 350 are each examples of a "protection circuit" in this invention. The protection circuit is directly connected to any cell unit, or indirectly connected via other protection circuits, monitors the state of the battery cells constituting the cell unit, and outputs a signal corresponding to the state of the battery cells. A circuit combining any one of the protection IC 300, protection IC 320, and control unit 350 is also an example of a "protection circuit" in this invention. Furthermore, the protection IC 300 is an example of the "first protection circuit" in this invention, the protection IC 320 is an example of the "second protection circuit" in this invention, and the control unit 350 is an example of the "control unit" in this invention. The control unit is directly connected to any cell unit or indirectly connected via other protection circuits. Moreover, the power supply circuit 321 is an example of the "power supply circuit" in this invention, and the power supply voltage (VDD1) is an example of the "power supply voltage" in this invention. Furthermore, the cell temperature detection component 331 is an example of both a "detection unit" and a "temperature detection unit" in this invention, and the current detection circuit 327 is an example of both a "detection unit" and a "current detection unit" in this invention. The temperature detected by the cell temperature detection component 331 and the current detected by the current detection circuit 327 are examples of "physical quantities" in this invention, respectively.

[0459] A shunt resistor 329 is provided on the grounding side of the lower cell unit 147, but no shunt resistor is provided on the upper cell unit 146 side. This is because when the upper cell unit 146 and the lower cell unit 147 are connected in series, the current value can be measured using only the shunt resistor 329. On the other hand, when the upper cell unit 146 and the lower cell unit 147 are connected in parallel, the measured current value on the upper cell unit 146 side cannot be measured. However, the control unit 350 can simply monitor the current value of the upper cell unit 146 as equivalent to that of the lower cell unit 147. Alternatively, a shunt resistor and a voltage detection circuit can be provided on the grounding side of the upper cell unit 146, and the current value on the lower cell unit 147 side can also be directly monitored by the microcomputer of the control unit 350.

[0460] The control unit 350 monitors the current value and cell temperature, and monitors the status of the upper cell unit 146 and the lower cell unit 147 to control their operation. Furthermore, in the event of an emergency stop of the power tool body 1, a discharge prohibition signal 341 is issued to change the potential of the LD terminal 168, thereby stopping the operation of the power tool body 1 via the LD terminal 28. Among these monitoring functions performed by the control unit 350, the most important is the amount of current flowing through the battery cells contained in the upper cell unit 146 and the lower cell unit 147. In recent years, with the improvement in battery cell performance and increased capacity, large currents can be drawn from the battery pack 100 in power tools. However, considering lifespan and heat generation, it is preferable to limit the current of the battery cells to a predetermined amount (below the upper current limit). Therefore, to specifically monitor the current flowing through the battery cells, the control unit 350 uses a shunt resistor 329 and a current detection circuit 327 located midway in the power supply line of the lower cell unit 147 to monitor the current value.

[0461] The protection circuit for managing the lower cell unit 147, which includes a protection IC 320, a control unit 350, a power supply circuit 321, and a current detection circuit 327, can also be integrated into a single chip to form a "battery management IC". On the other hand, the protection IC 300 for the upper cell unit 146 can be used in a conventional battery pack 15 (see reference 146). Figure 1The same protection IC widely used in [the context of battery protection IC] is commercially available as a "battery protection IC" for five-cell batteries. The operation of protection IC 320 is largely the same as protection IC 300. When it detects that the voltage of a battery cell in the lower cell unit 147 has dropped to a predetermined lower limit (over-discharge state), it sends an over-discharge signal 325 to the control unit 350. Furthermore, when the battery pack 100 is charged using an external charging device (not shown), protection IC 320 sends an overcharge signal 326 indicating an overcharge state to the control unit 350 when it detects that the voltage of a battery cell exceeds a predetermined upper limit. The control unit 350 communicates via LS terminal 166 (see [reference]). Figure 4 The charging stop signal is sent to the charging device (not shown). As explained above, the upper cell unit 146 and the lower cell unit 147 are each equipped with a protection circuit for the battery cell, thus enabling battery protection through extremely precise battery monitoring.

[0462] In this embodiment, the protection circuit of the upper cell unit 146 only contains the protection IC 300 and does not include a microcomputer. In contrast, the protection circuit of the lower cell unit 147 includes a control unit 350 containing a microcomputer, in addition to the protection IC 320. Furthermore, the power supply circuit 321 uses the power from the lower cell unit 147 to generate the power for the operation of the control unit 350. The battery pack 100 in this embodiment is a voltage switching type between 18V and 36V. When a microcomputer is installed in the protection circuit on the upper cell unit 146 side, the ground potential of the control unit 350 changes when the two cell units are connected in series and in parallel. On the other hand, if the power supply circuit 321 is provided on the lower side, the ground potential of the power supply circuit 321 will not change. Therefore, in this embodiment, the control unit 350 with a microcomputer is not located in the circuit of the upper cell unit 146, but in the circuit of the lower cell unit 147. With the configuration of the microcomputer, the control unit 350, which includes the microcomputer, can operate stably even when the output voltage switches between the rated 18V and 36V. The ground potential of the control unit 350 is equivalent to the "ground potential of the control unit" in this invention.

[0463] The practice of placing the control unit 350, which includes a microcomputer, in only one of the battery cell units leads to an imbalance in power consumption between the two battery cell units. Although the power consumption of the control unit 350 is extremely small, the power consumption on the lower battery cell unit 147 side will be greater than that on the upper battery cell unit 146 side. Prolonged power imbalance will cause the potential on the lower battery cell unit 147 side to become lower than that on the upper battery cell unit 146, which is undesirable. In particular, when the upper battery cell unit 146 and the lower battery cell unit 147 are connected in parallel to achieve a rated 18V output, circulating current will flow immediately after the parallel connection is established due to the voltage imbalance between the battery cell units. Therefore, in this embodiment, a current consumption control unit 310 is provided in the circuit of the upper battery cell unit 146, which has lower power consumption. This current consumption control unit 310 has the function of adjusting the current consumption of the lower battery cell unit 147. The current consumption control component 310 is connected in parallel with the lower power consumption side of the two battery cells, here the upper battery cell 146, and is mounted on the circuit board 150 (see reference) as a load circuit independent of the integrated protection IC 300. Figure 4 The current consumption control component 310 is an example of a "current consumption control unit" in this invention.

[0464] The current consumption control unit 310 is controlled to operate in conjunction with the operation of the control unit 350. The microcomputer included in the control unit 350 can switch between maintaining and de-regulating the power supply voltage (VDD1) applied to it, having a normal operating state (normal mode) and an operating stop state (so-called sleep state). While the microcomputer of the control unit 350 maintains the power supply voltage VDD1, the protection IC 300 also activates by switching the state of the start terminal 301, which serves as a control signal. In this embodiment, the circuitry of the current consumption control unit 310 is carefully designed such that once the microcomputer of the control unit 350 maintains the power supply voltage VDD1, a current for power consumption adjustment flows through the current consumption control unit 310, and the current consumption control unit 310 then switches the state of the start terminal 301. As a result, the protection IC 300 activates simultaneously with the activation of the control unit 350. Since the power supply circuit 321 of the control unit 350 is shared with the protection IC 320, the protection IC 320 is also activated when the microcomputer is started. Through the current consumption control component 310, the current consumption of the battery cell group (lower battery cell unit 147) connected to the control unit 350 and the other battery cell group (upper battery cell unit 146) becomes the same.

[0465] The current consumption control unit 310 is an electrical circuit comprising multiple switching elements M31 to M33, including a field-effect transistor (FET), and multiple resistors (resistors R31 to R35). The basic circuit structure is as follows: resistors R31 and R34, acting as two dummy loads, are connected in series between the two terminals of the upper battery cell 146, and this circuit is switched on or off by the switching element M32. The source terminal of the switching element M32 is connected to the positive terminal of the upper battery cell 146, and the drain terminal is connected to resistor R31. The gate terminal of the switching element M32 is connected to the junction of resistors R32 and R35. One end of resistor R32 is connected to the source terminal of the switching element M32, and the other end is connected to the gate terminal of the switching element M32. One end of resistor R35 is connected to the gate terminal of the switching element M32, and the other end is connected to the drain terminal of the switching element M33. Switching element M33 receives a gate signal from the power supply voltage (VDD1) of the microcomputer included in control unit 350, and switches between on and off states in conjunction with the power supply voltage VDD1. The source terminal of switching element M33 is grounded, and a resistor R33 is connected between the source terminal and the gate terminal of switching element M33. Resistor R33 is configured to stably switch switching element M33 according to changes in the gate signal voltage. When the power supply voltage VDD1 of the microcomputer is on, the gate potential of switching element M33 is VDD1 (high level); when the power supply voltage VDD1 is off, the gate potential of switching element M33 is 0V (low level). Additionally, a signal identical to the gate signal of switching element M33 is also input to protection IC 320. Thus, switching element M33 becomes off. When switching element M33 is in the off state, switching element M32 is also in the off state. Therefore, the current path to the dummy load side formed by resistors R31 and R34 is blocked, and the power consumption of the current consumption control unit 310 is zero. In order to make the protection IC 300 also off in this state, a switching element M31 is also provided. The potential of the connection point of input resistors R31 and R34 is used as the gate signal (action signal 302). The drain terminal of the switching element M31 is connected to the start terminal 301 of the built-in power supply (not shown) of the protection IC 300, and the source terminal is connected to the negative terminal of the upper battery cell 146. The action signal 302 is a signal indicating the operating status of the current consumption control unit 310. When it is high, it indicates that the current consumption control unit 310 is running, that is, the microcomputer of the control unit 350 is also running. On the other hand, when the current consumption control component 310 is not running, that is, when the microcomputer of the control unit 350 is stopped, the action signal 302 goes low, the start terminal 301 becomes a high impedance state, and thus the protection IC 300 stops.

[0466] The potential of the negative terminal (reference potential A) of the upper battery cell 146 is ground potential when the upper battery cell 146 and the lower battery cell 147 are connected in parallel, but it is equal to the potential of the positive terminal of the lower battery cell 147 when they are connected in series. In this connection state, the potential of the upper battery cell 146 is not applied to resistor R31, the switching element M31 becomes open, and therefore the start terminal 301 becomes an unconnected high-impedance state. On the other hand, when the switching element M32 becomes on and current flows through the dummy load, the voltage divided by resistors R31 and R32 is applied to the gate terminal of the switching element M31, so the switching element M31 becomes on. Thus, the start terminal 301 is connected to the reference potential A, thereby supplying power to the built-in power supply in the protection IC 300, thereby activating the protection IC 300. According to the connection configuration described above, the current consumption control component 310 can consume power in the circuit of the upper battery cell 146 that corresponds to the power consumption of the microcomputer in the control unit 350 on the lower battery cell 147 side. Furthermore, by switching the operation and shutdown of the current consumption control component 310, the start and stop control of the protection IC 300 itself can also be performed simultaneously. Therefore, the microcomputer of the control unit 350 can control the start or stop of the protection circuit of the lower battery cell 147 and the protection circuit of the upper battery cell 146 in a coordinated manner.

[0467] The microcomputer in the control unit 350 has three states: normal, sleep, and shutdown. Normal is when the microcomputer is always running. Sleep is a mode where the microcomputer starts intermittently, repeating the action of starting for 50 milliseconds and then stopping for 5 seconds. Shutdown is a state where the power supply voltage VDD1 is completely cut off, and the microcomputer is completely stopped. The microcomputer operates whether the battery pack 100 is installed in the power tool body 1 or not. However, when the battery pack 100 is not installed, or even if it is installed but the power tool has not been used for a certain period of time (e.g., approximately two hours after the trigger operation), the microcomputer enters a sleep state. Even in the sleep state, the current consumption control unit 310 still operates in conjunction with the microcomputer's startup, and the protection IC 300 is also activated via the current consumption control unit 310. When the trigger switch 4 of the power tool body 1 is pulled and current flows through the motor 5, the microcomputer of the control unit 350 detects the increase in the current value detected by the current detection circuit 327 and returns to the normal state.

[0468] In this embodiment, when a structure is adopted in which only one of the multiple battery cells has a protection circuit containing a microcomputer, by adding a current consumption control component 310 that controls the power consumption corresponding to the microcomputer to the protection circuit of the other battery cells without a microcomputer, the problem of the expansion of the potential difference between multiple battery cells caused by the battery pack being stored in a disassembled state for a long time is solved. Therefore, the balance of the current consumption of each of the multiple battery cells can be adjusted, thereby enabling a battery pack in which the voltage balance of each battery cell does not deteriorate even after long-term storage.

[0469] The battery pack 100 is provided with a remaining capacity display component 335 that displays the remaining battery power. When the remaining power display switch 190 (see reference) is activated... Figure 4 When pressed, the remaining battery power is displayed by the number of lights emitted by the four LEDs (not shown). Although not shown, the signal from the switch 190 for displaying the remaining power is input to the control unit 350, and the microcomputer of the control unit 350 controls the lighting of the LEDs in the remaining capacity display component 335. Here, the remaining battery power displayed by the remaining capacity display component 335 can be based on the voltage across one of the upper cell unit 146 and the lower cell unit 147, or it can be based on the lowest voltage value among the ten battery cells.

[0470] The control unit 350 receives the output of the upper voltage detection circuit 322, which is connected to the upper positive terminal 162. This output indicates the potential of the upper cell unit 146 when the battery pack 100 is not installed in the power tool body 1, 30, or an external charging device (not shown). On the other hand, when installed in the power tool body 1 for low voltage (18V), since the upper positive terminal 162 is connected to the lower positive terminal 172, the positive terminals of the upper cell unit 146 and the lower cell unit 147 are at the same potential, and their negative terminals are at the same potential. Accordingly, the microcomputer included in the control unit 350 can determine whether the battery pack 100 is in an uninstalled state, installed in a low-voltage device body, or installed in a high-voltage device by comparing the potential of the upper positive terminal 162 with the potential of the lower positive terminal 172. Furthermore, for potential detection of the lower positive terminal 172, the control unit 350 can be configured to acquire the positive terminal potential of the uppermost battery cell 147a within the lower cell unit 147. In this way, the microcomputer in the circuit of the lower cell unit 147 can determine whether the upper cell unit 146 and the lower cell unit 147 of the battery pack 100 are connected in series (in a 36V device) or in parallel (in an 18V device). Thus, the microcomputer can also monitor the voltage value on the upper cell unit 146 side that exceeds the power supply voltage acquisition range (the voltage within the lower cell unit 147), thereby enabling the determination of the connection state of the battery pack 100 in voltage switching mode and optimal control corresponding to the determined connection state. The upper voltage detection circuit 322 is an example of the "detection unit" and "first voltage detection unit" in this invention, and the potential of the upper battery cell 146 is an example of the "physical quantity" and "voltage of the first battery cell" in this invention.

[0471] The LD terminal 168 is used to transmit signals such as a signal from the battery pack 100 side to stop the power tool body 1, or a signal to stop the operation of an electrical device powered by a battery pack (not shown). To change the state of the LD terminal 168, the control unit 350 switches the gate signal (discharge prohibition signal 341) input to the semiconductor switching element M41 from its normal low state ("discharge permission" from the battery pack 100) to a high state ("discharge prohibition" from the battery pack 100). The switching element M41 is, for example, a P-type field-effect transistor (FET), with its drain connected to the LD terminal 168 and its source grounded. Therefore, when the switching element M41 is normally in operation (discharge prohibition signal 341 is low), the LD terminal 28 is in a high-impedance state, and the potential of the LD terminal 28 is approximately equal to the voltage of the positive input terminal 22 on the power tool body 1 side. On the other hand, when the discharge inhibit signal 341 is switched high by control from the control unit 350, the source-drain of the switching element M41 is grounded through conduction. Therefore, the potential of the LD terminal 28 on the power tool body 1 side will drop to the ground potential. As a result, due to the drop in the gate potential of the switching element M101 on the power tool body 1 side, that is, the voltage divider potential formed by the voltage divider resistors R101 and R102, the source-drain of the switching element M101 becomes non-conductive, the power circuit of the power tool body 1 is blocked, and the rotation of the motor 5 is stopped. In this way, the discharge prohibition signal 341 issued by the control unit 350 of the battery pack 100 can prevent the rotation of the motor 5 of the power tool body 1. Therefore, when the control unit 350 has to stop the power supply from the battery pack 100, for example, when excessive current occurs during discharge, the cell voltage drops during discharge (over-discharge), or the cell temperature rises abnormally (over-temperature), the operation of the power tool or electrical equipment can be stopped as soon as possible. This not only protects the battery pack 100, but also protects the power tool body 1.

[0472] Figure 20 This is a circuit diagram of the battery pack 100 in this embodiment, showing its connection to an 18V power tool body 1A equipped with a microcomputer on the main body. Here, the internal structure of the battery pack 100 is similar to... Figure 19 The two are exactly the same, except for the structure of the power tool body 1A side. Figure 19The power tool body 1 shown does not include a microcomputer. However, in recent years, power tools have increasingly used control units 60 with microcomputers to control the motor 5. The power tool body 1A includes a power supply circuit 61, and the control unit 60 operates based on a fixed low voltage (reference voltage VDD2) generated by the power supply circuit 61. The control unit 60 includes a microcomputer, which monitors or controls various states within the power tool body 1A. A switch state detection circuit 63 is connected to the control unit 60, which outputs a high or low signal based on the connection state between the output of the battery voltage detection circuit 62 and the trigger switch 34. In this embodiment, a DC motor 35 is provided in the power path between the positive input terminal 22 and the negative input terminal 27. This circuit includes an operation switch 34 (trigger switch) for turning the motor 35 on or off. A semiconductor switching element M101 and a shunt resistor R111 are inserted between the motor 35 and the negative input terminal 27. The switching element M101 is, for example, a FET (Field-Effect Transistor), whose gate signal is sent out by the control unit 60. The voltage across the shunt resistor R111 is detected by the current detection circuit 64, and its value is output to the control unit 60. In this circuit diagram, the motor 35 is shown as a brushed DC motor, but a structure using a known inverter circuit to drive a three-phase brushless motor can also be used. In this case, the rotation of the motor 35 can be stopped simply by connecting the switching element M101 in series in the power path input to the inverter circuit (not shown), or by having the control unit 60 control the switching element (not shown) contained in the inverter circuit instead of the switching element M101.

[0473] The LD terminal 28 of the power tool body 1A is connected to the control unit 60 via resistor R112. A reference voltage VDD2 is also connected to the control unit 60 side of resistor R112 via resistor R113. Therefore, when the LD terminal 28 is in a high-impedance state, a voltage close to VDD2 is applied to the input line 65 of the control unit 60. When the LD terminal 28 drops to ground potential, the voltage divided by resistors R113 and R112, i.e., a voltage significantly lower than the reference voltage VDD2, is transmitted to the input port of the control unit 60 through the input line 65. The control unit 60 controls the power supply to the motor 35 by detecting the potential change of the input line 65 and controlling the gate signal of the switching element M101.

[0474] Thus, on the power tool body 1A side, a circuit is provided to stop the motor 35 based on a discharge prohibition signal input via LD terminals 168 and 28. However, when the power tool body 1A side has a control unit 60, it is preferable that the motor 5 on the power tool body 1A side is not stopped by the control unit 350 on the battery pack 100 side monitoring overcurrent, but rather that the control unit 60 on the power tool body 1A side directly monitors overcurrent using the current detection circuit 64. When overcurrent monitoring is performed by the control unit 350 on the battery pack 100 side, an average control condition (overcurrent threshold) applicable to multiple power tool bodies must be set. However, when overcurrent monitoring is performed by the control unit 60 on the power tool body 1A side, the control condition most suitable for the power tool body 1A (overcurrent high threshold) can be set, thus avoiding output limitations caused by the control unit 350 setting an average control condition (overcurrent low threshold). This avoidance of output limitations is particularly effective in new power tools to be released in the future, enabling control that maximizes the capabilities of the new power tool body 1A.

[0475] In this embodiment, the control unit 350 on the battery pack 100 side determines whether the power tool body 1 or 1A on which the battery pack 100 is installed includes a control unit 60 with a microcomputer, and changes the overload protection conditions for the battery pack 100 side based on the determination result. Specifically, as Figure 19In the case where the power tool body 1 does not include a microcomputer, the overcurrent limit value during low-voltage output is set to a threshold value, such as 20A (default value), used by the power tool body 1A without a microcomputer. The default value can be set appropriately based on the capacity or performance of the battery cells used. Since the overcurrent limit value is set to the same value as that set in the conventional battery pack 15, the battery pack 100 of this embodiment can be used to drive the conventional power tool body 1A without a microcomputer. On the other hand, when the power tool body 1A includes a microcomputer, the overcurrent limit value during low-voltage output is not set on the battery pack 100 side, and the monitoring of the overcurrent value is delegated to the microcomputer of the control unit 60 on the power tool body 1A side. As a result, the control unit 60 can perform optimal current monitoring that matches the characteristics of the motor 5 used or the structural characteristics of the power tool body 1A, thereby avoiding the problem of the power tool body 1A's capabilities being ineffective due to excessive overcurrent limit on the battery pack 100 side. Furthermore, the power tool body 1A can maximize the capacity of the battery pack 100 to achieve a high-output power tool. Changing the overload protection conditions for the battery pack 100 side on the low-voltage and high-voltage sides in this way means that not only is there room for further high-output and improvement of the low-voltage power tool body sold in the future, but also the control unit 60 on the power tool body side can perform the most suitable overload protection for the power tool body 1A.

[0476] To determine whether the power tool body 1 or 1A contains a control unit 60 with a microcomputer, a new LD terminal voltage detection circuit 328 is provided within the battery pack 100. This LD terminal voltage detection circuit 328 detects the voltage applied to the LD terminal 28. The LD terminal voltage detection circuit 328 is connected to the LD terminal 168 via a connecting line 342, and outputs a voltage corresponding to the terminal voltage to the control unit 350. The microcomputer within the control unit 350 measures the LD terminal voltage after the battery pack 100 is installed and before a discharge prohibition signal 341 is issued, thereby determining whether the power tool body contains a control unit 60 with a microcomputer. If the power tool body 1 does not have a microcomputer, then according to... Figure 19 As can be seen from the circuit diagram, the LD terminal 28 is in a state where a voltage approximately equal to that of the positive input terminal 22 is applied. The microcomputer of the control unit 350 detects the voltage of the upper positive terminal 162 through the upper voltage detection circuit 322. Therefore, by comparing the voltage of the upper positive terminal 162 with the voltage of the LD terminal, it is possible to determine whether the power tool body 1 contains a microcomputer. On the other hand, according to Figure 20As can be seen from the circuit diagram, if the power tool body 1A is equipped with a microcomputer, a voltage approximately equal to the reference voltage VDD2 (e.g., 5V or 3.3V) used for driving the microcomputer is applied to the LD terminal 28. Therefore, the microcomputer of the control unit 350 does not even need to compare the voltage of the upper positive terminal 162 with the voltage of the upper voltage detection circuit 322; it can easily determine that the power tool body 1A contains a microcomputer simply by detecting the voltage of the LD terminal. As described above, by providing the connection line 342 and the LD terminal voltage detection circuit 328 in the battery pack 100, the control unit 350 can easily determine whether it is a tool that supports electronic control and has a low-voltage driven control unit such as a microcomputer on the power tool body or electrical equipment body side, or a tool that does not support it. Moreover, the control unit 350 can change the control parameters used for battery cell monitoring, such as overload protection conditions, according to the determination result. Here, the value of the changed control parameter only needs to be stored in the non-volatile memory contained in the microcomputer in advance, and any one of the stored values ​​can be read and set according to the determination result. The LD terminal voltage detection circuit 328 is an example of the "detection unit" and "second voltage detection unit" in this invention, and the voltage of the LD terminal 168 is an example of the "physical quantity" in this invention.

[0477] Figure 21 This is a circuit diagram showing the power tool body 30 capable of supporting high loads with the battery pack 100 installed. A key feature of the power tool body 30 capable of supporting high loads is the presence of device-side terminals (positive input terminal 52, negative input terminal 57, and shorting bar terminal portions 59b and 59c) corresponding to the positive terminals (162, 172) and negative terminals (167, 177) of the battery pack 100, respectively. The shorting bar 59 is a metal part with a terminal portion 59b at one end and a terminal portion 59c at the other end. When the battery pack 100 is installed on the power tool body 30, the lower positive terminal 172 and the lower negative terminal 177 are short-circuited through the shorting bar 59. Furthermore, the positive input terminal 52 of the power tool body 30 is connected to the upper positive terminal 162, and the negative input terminal 57 is connected to the upper negative terminal 167. By using the shape of the body-side terminals, which are divided into two sections, an output of 36V can be obtained by connecting the upper battery cell 146 and the lower battery cell 147 in series. The structure of the power tool body 30 side is similar to... Figure 20 The internal structure of the power tool body 1A shown is roughly the same. Motor 45 is a 36V rated motor, but... Figure 20Similarly, the motor 35 shown can also be driven by an inverter circuit to drive a brushless DC motor. A switching element M101 is provided in series with the power circuit for the motor 45. The switching element M101 is controlled to be turned on or off according to the gate signal output from the control unit 60. By setting the switching element M101 to off, the rotation of the motor 45 is stopped. In the high-voltage power tool body 30, the transmission process of the discharge inhibition signal 341 from the battery pack 100 side is also similar to... Figure 19 , Figure 20 The circuit shown is exactly the same. That is, under the control of the control unit 350 on the battery pack 100 side, the source-drain of the switching element M41 is turned on. When the LD terminal 168 drops to the ground potential, its state is transmitted to the input port of the microcomputer contained in the control unit 60. Therefore, the control unit 60 can detect the discharge prohibition signal from the battery pack 100 side. However, in the 36V power tool body 30, the discharge prohibition control based on overcurrent is performed by the control unit 60 on the tool body side, while the battery pack 100 side does not participate in the monitoring of overcurrent, or the overcurrent-based stop threshold is sufficiently raised to near the limit value of the battery cell. The microcomputer of the control unit 350 can substantially not participate in the monitoring of the current value. As a result, it is possible to well balance the further high output of the battery pack 100 and the maintenance of compatibility with the conventional battery pack 15.

[0478] Next, use Figure 22 This section explains the output process of the discharge prohibition signal by the control unit 350 of the battery pack 100. Figure 22 The series of processes shown can be executed in software by a microcomputer using a program pre-stored in the control unit 350, and will be executed automatically once the battery pack 100 is started. First, the microcomputer determines whether the connected power tool body is a low-voltage (18V) device or a high-voltage (36V) device, and thereby determines whether the upper cell unit 146 and the lower cell unit 147 of the battery pack 100 are connected in parallel or in series (step 371). If they are connected in series, the parameters for series connection are set as control parameters for the control unit 350 (step 372). Furthermore, if they are connected in parallel, the control parameters for parallel connection are set (step 373). Here, the current limit value I is considered, for example, as a control parameter. max Upper limit of cell voltage V during charging max The lower limit of cell voltage V during discharge min The upper limit of cell temperature T max Etc. Here, the discharge current limit value I during parallel connection is... max Set to 20A, without setting the discharge current limit value I when connected in series. max(Unlimited value) or set to a value significantly greater than that for parallel connection (e.g., around 40-80A). Upper limit T of cell temperature during discharge. max Regardless of whether there is a series or parallel connection, the temperature is 80℃. The lower limit of the cell voltage V during discharge. min Regardless of whether it is connected in series or in parallel, it is 2.5V per cell.

[0479] Next, the microcomputer determines whether any cell voltages have reached the specified lower limit value V based on the monitoring results of each battery cell contained in the lower cell unit 147. min The following battery cells (step 374). Here, if any battery cell reaches the lower limit of cell voltage V... min Proceed to step 378. If the voltage of all cells is greater than the lower limit of cell voltage V... min Next, it is determined whether the over-discharge signal 305 from the protection IC 300 side has gone high (step 375). The over-discharge signal going high means that any battery cell in the upper cell unit 146 is at the lower limit of its cell voltage V. min Next, proceed to step 378. If the result in step 375 is No, then determine whether the peak current value detected by the current detection circuit 327 is above the predetermined threshold I1 (step 376). Here, the detection of the peak current value I can be either purely monitoring the instantaneous value of the peak current, or a certain time window can be defined, and the average current within this time window can be used for detection, thereby eliminating the influence of the current that protrudes in a spire shape. In addition, when the upper cell unit 146 and the lower cell unit 147 are connected in series and no cell current limit value I is set. max In this case, skip step 376 and proceed to step 377.

[0480] Next, it is determined whether the battery temperature detected by the cell temperature detection component 331 is above the specified threshold T1 (step 377). Here, thermistors TH1 and TH2 are respectively installed in the upper cell unit 146 and the lower cell unit 147 to measure the temperature. Once the temperature of either reaches or exceeds the threshold T1, the process proceeds to step 378. If, in step 377, the temperature of either is below the threshold T1, the process returns to step 371. If it is above the threshold T1, the microcomputer of the control unit 350 sends a discharge prohibition signal 341 to stop the motors 5, 35, and 45 of the power tool body 1, 1A, and 30, and sets the switching element M41 to conduct. As a result, the LD terminal 168 drops to the ground potential, and the process returns to step 371 (step 378). By repeating the above process, the control unit 350 can monitor the state of the battery cells and, as needed, stop the operation of the power tool or electrical equipment equipped with the battery pack 100 by using the discharge prohibition signal 341.

[0481] Next, use Figure 23 This section explains the specific circuit structure of the remaining capacity display component 335 and the upper voltage detection circuit 322 of the battery pack 100. Figure 23 The structure of the remaining capacity display component 335 and the upper voltage detection circuit 322 are described in detail, as well as other structures on the battery pack 100 side. Figures 19-21 The battery pack 100 is identical. The microcomputer of the control unit 350 has a group of input / output ports 353, four of which are connected to light-emitting diodes LD0 to LD3 within the remaining capacity display unit 335. Furthermore, within the remaining capacity display unit 335, a switching element M0 is provided between the power supply voltage VDD1 and each of the light-emitting diodes LD0 to LD3. One of the four input / output ports IO0 to IO3, IO0, is connected to the gate. The other of the four input / output ports (IO3) is connected to the gate terminal of the switching element M3. The switching element M3 is used to control the connection or disconnection between the source and drain of the switching element M4.

[0482] The basic structure of the upper voltage detection circuit 322 includes resistors R6 and R7, whose midpoint potential serves as the voltage of the upper cell unit 146 (upper voltage detection) and is input to the input port AN of the control unit 350. Between resistor R6 and the upper positive terminal 162, there is a switching element M4 containing a FET. The gate terminal of the switching element M4 is connected to the drain terminal of the switching element M3, which is controlled by the input / output port IO3. That is, when the light-emitting diode LD3 is off, when the input / output port IO3 becomes open, the switching element M3 becomes open, and therefore the gate potential of the switching element M4 remains high, thus the source and drain of the switching element M4 are connected (turned on), and the upper voltage detection is input to the input port AN0 of the microcomputer. The input port group 352 (AN0, AN1, etc.) has an analog-to-digital (A / D) conversion function that converts the input analog signal into a digital signal. On the other hand, when IO3 is set high in order to light up the LED LD3, the switching element M3 becomes on, and therefore the gate terminal of the switching element M4 drops to ground potential, thus blocking (disconnecting) the source and drain of the switching element M4. By connecting in the above manner, the control unit 350 can use the input port AN0 to detect the voltage of the upper positive terminal 162.

[0483] As described above, in the control unit 350, in addition to the input port AN0 for inputting the voltage of the upper positive terminal 162, two input ports AN1 and AN2 are also required for inputting the output of the cell temperature detection unit 331, for a total of three ports. The cell temperature detection unit 331 includes a thermistor TH1 for measuring the temperature of the upper cell unit 146 and a thermistor TH2 for measuring the temperature of the lower cell unit 147. However, if a microcomputer with three input ports AN0 to AN2 were prepared to input the voltage of the upper positive terminal 162, the output of the thermistor TH1, and the output of the thermistor TH2, it would increase the cost of the microcomputer or require a larger chip size. Therefore, Figure 24 The structure is carefully designed so that the three inputs share a single input port AN0.

[0484] Figure 24 This is the input / output circuit diagram of the microcomputer 351 within the control unit 350. Figure 24In this microcomputer 351, there are input port group 352 and input / output port group 353. Input port group 352 has the function of converting input analog signals into digital signals. One of the input ports, AN1, is connected as a signal input from thermistors TH1 and TH2 and the upper voltage detection circuit 322A. Input / output port group 353 is a combined input / output port that serves as both an input port and an output port. Here, the four input / output ports IO0 to IO3 are respectively connected to light-emitting diodes (LD0 to LD3). A switching element M0 is connected to input / output port IO0. The switching element M0 is used to control the on / off state of the power supply (VDD1) to the light-emitting diodes LD0 to LD3. A resistor R5 is connected between the gate and source of the switching element M0. The switching element M0 and the resistor R5 form a switching component 364 for controlling the lighting or extinguishing of the light-emitting diodes LD0 to LD3. Input / output ports IO1 to IO3 are connected to LEDs LD1 to LD3, and are respectively connected to the gate terminals of switching elements M1 to M3.

[0485] One terminal of each of the two thermistors TH1 and TH2 is connected to the reference voltage VDD1 of the microcomputer 351 via a common resistor Ra, and the other is connected to the ground wire via switching elements M1 and M2. Thermistors TH1 and TH2 are, for example, NTC thermistors with a resistance value that decreases as the temperature rises. By placing them near the battery cells, the microcomputer 351 measures the temperature of the battery cells. Here, thermistor TH1 can be placed near the upper battery cell unit 146, and thermistor TH2 can be placed near the lower battery cell unit 147. Switching elements M1 to M3 are semiconductor switches capable of electrically switching on or off. The drain terminals of switching elements M1 and M2 are connected to the other terminals of TH1 and TH2, and the source terminals are connected to the ground wire. The drain terminal of switching element M3 is connected to the upper voltage detection circuit 322A via a resistor Rb, and the source terminal is connected to the ground wire. The gate terminals of these switching elements M1 to M3 are respectively connected to the input / output ports IO1 to IO3 of the microcomputer 351, and the source terminals are grounded. In order to set the gate-source voltage to 0V when the input / output ports IO1 to IO3 are turned on, grounding resistors R6 to R8 are respectively provided between the gate terminals and the source terminals of the switching elements M1 to M3.

[0486] The four LEDs LD0 to LD3 can be of any color; here, green or red LEDs are used. Resistors R0 to R3 for current limiting are connected in series in the circuit for LEDs LD0 to LD3. Resistors R0 to R3 can be resistors of the same value. Here, the input / output port IO0 connects to both the gate terminal of the switching element M0 and the LED LD0. By connecting the switching element M0 and the LED LD0 in parallel to the input / output port IO0, the input / output port IO0 can be set to either high or low. The circuit enclosed by the dashed line serves as a switching component 364 to switch whether all LEDs LD0 to LD3 are lit. To light the other LEDs LD1 to LD3, while LED LD0 is lit, the outputs of the input / output ports IO1 to IO3 are further set low (to ground potential), thus enabling them to light up.

[0487] When LEDs LD0 to LD3 are off, input / output ports IO1 to IO3 select one signal from thermistors TH1 and TH2, or the upper voltage detection circuit 322A, to input to input port AN1. That is, when input / output port IO0 is set low, any one of the outputs of input / output ports IO1 to IO3 is switched high, thus allowing the outputs of thermistors TH1 and TH2, or the upper voltage detection circuit 322A, to be selectively input to input port AN1. Furthermore, even when any one of LEDs LD0 to LD3 is lit, as long as the signal of input / output port IO0 is set to a high impedance state only during the period when the microcomputer 351 acquires the outputs of thermistors TH1 and TH2, or the upper voltage detection circuit 322A, these outputs can be sequentially input to input port AN1 according to a time sequence. When input is applied to input port AN1, all LEDs LD0 to LD3 are turned off. However, during this off state, temperature detection is performed via thermistors TH1 and TH2, or voltage detection is performed via the upper voltage detection circuit 322A, causing LEDs LD0 to LD3 to return to their original lit state. That is, the following process is repeated: LEDs off → detection via thermistor TH1 → LEDs are lit again for a fixed time and then off → detection via thermistor TH2 → LEDs are lit again for a fixed time and then off → voltage detection via the upper voltage detection circuit 322A → LEDs are lit again. The time required for temperature detection via the thermistors TH1 and TH2 and voltage detection via the upper voltage detection circuit 322A is, for example, 1 millisecond. If these detections are performed sequentially at 50-millisecond intervals, there is a 49-millisecond lighting time after the 1-millisecond off period. Therefore, the three detections—temperature detection via the thermistors TH1 and TH2 and voltage detection via the upper voltage detection circuit 322A—can be completed within 150 milliseconds. At this time, if any one of the LEDs LD0 to LD3 is lit, there is a 1-millisecond off period for the LED every 50 milliseconds. However, with this level of off interval, it appears to the human eye as if the LED is continuously lit, so temporary off periods do not cause any problems.

[0488] Figure 25 It means Figure 24This table shows the correspondence between the input / output ports IO0 to IO3 and the output states of each output device. The vertical axis represents the lighting state of the light-emitting diodes (LEDs) and the voltage detection state via thermistors TH1 and TH2 and the voltage detection state via the upper voltage detection circuit 322A. The signal levels of the input / output port group 353 at this time are represented by columns 353a and 353b. For example, when the battery capacity is 25% to 50%, only LED LD0 is lit; when it is 50% to 75%, LEDs LD0 and LD1 are lit; when it is 75% to less than 100%, LEDs LD0 to LD2 are lit; and when it is fully charged, LEDs LD0 to LD3 are lit. The control of lighting LEDs LD0 to LD3 will be explained first. To light only LED LD0 (LD0: ON), as shown in line 2 of column 353a, set only input / output port IO0 to low (ground potential) and set IO1-IO3 to high impedance. To light both LEDs LD0 and LD1 (LD0, LD1: ON), as shown in line 353a, set input / output ports IO0 and IO1 to low and set IO2 and IO3 to high impedance. To light all three LEDs LD0-LD2 (LD0, LD1, LD2: ON), as shown in line 4 of column 353a, set input / output ports IO0-IO2 to low and set only IO3 to high impedance. To light all LEDs LD0-LD3 (LD0, LD1, LD2, LD3: ON), as shown in line 5 of column 353a, set all input / output ports IO0-IO3 to low. By controlling it in this way, the remaining battery power can be displayed by lighting up the LEDs LD0 to LD3. Furthermore, by setting the input / output port IO0 to high impedance as shown in column 353a, all LEDs LD0 to LD3 can be turned off.

[0489] When detecting temperature using thermistors TH1 and TH2, as shown in column 353b, simply set input / output port IO0 in input / output port group 353 to high and set the signal level of either thermistor TH1 or TH2 to high (VDD1 potential). For example, when detecting temperature using thermistor TH1, simply setting IO1 to on (high) turns on the switching element M1, applying a specified voltage across the thermistor TH1, and the microcomputer 351 can detect the voltage value of thermistor TH1 from input port AN1. When detecting temperature using thermistor TH2, simply setting IO2 to on (high) turns on the switching element M2, and the microcomputer 351 can detect the voltage value of thermistor TH2 from input port AN1. When voltage detection is performed via the upper voltage detection circuit 322A, as long as the input / output port IO0 is set high and IO3 is set to ON (high), the switching element M3 becomes ON, and the microcomputer 351 can detect the voltage value of the upper voltage detection circuit 322A (upper battery cell unit 146) from the input port AN1. At this time, the input / output ports IO1 and IO2 must be set low beforehand. In this way, with the signal of IO0 set high regardless of its state, the signal levels of IO1 to IO3 are switched from low to high in sequence. In addition, even if the input / output port IO0 is set to a high impedance state as an OFF state instead of high, temperature detection via thermistors TH1 and TH2 and voltage detection via the upper voltage detection circuit 322A can be performed selectively. As described above, by using the signals of the input / output ports IO1 to IO3, multiple input signals are switched and input to the input port AN1, so only one input port AN1 is required, thereby saving the number of input ports.

[0490] Example 2

[0491] Figure 26 This is a circuit diagram of the battery pack 100A according to the second embodiment of the present invention, showing its connection state with a conventional power tool body 1. The rated voltage of the battery pack 100A is 18V, and it cannot be switched. Figures 19-21 The control unit containing a microcomputer described herein is applicable to the voltage-fixed battery pack 100A, but not to the voltage-switching battery pack 100. Figure 26 In the middle, the power tool body 1 shown on the left is... Figure 19 The power tool body 1 shown is exactly the same. Battery pack 100A is from... Figure 19The battery pack 100 shown has the upper cell unit 146 and its associated protection circuit (protection IC 300), current consumption control unit 310, lower positive terminal 172, and lower negative terminal 177 removed. Here, the same components or circuits are labeled with the same symbol number. Regarding cell unit 148, it is substantially the same as the lower cell unit 147, but there is no difference between upper and lower, and the shape of the battery cell separator (not shown) is slightly different; therefore, it is labeled with a different symbol number. In the conventional battery pack 15, this was not provided. Figure 26 The control unit 350 shown only uses the protection IC 320 to monitor the battery cell 148. However, in this embodiment, in addition to the protection IC 320, a control unit 350 with a microcomputer is added to the battery cell protection circuit. By using a protection circuit with a microcomputer, it is possible to determine whether the power tool body side contains a microcomputer on the battery pack 100A side, and change the control of the microcomputer on the battery pack 100A side according to its presence or absence.

[0492] Once the battery pack 100A is installed in the power tool body 1 and the trigger switch 34 is pulled, allowing current to flow, the control unit 350 either starts up or resumes from sleep mode to normal mode. During startup to normal mode, the battery pack 100A measures the voltage at the LD terminal 168 via the LD terminal voltage detection circuit 328. This measurement allows the control unit 350 to detect whether the power tool body 1 contains a microcomputer, and thus, if a microcomputer is present, to change the control parameters. Figure 26 In the example, the control unit 350 determines that the power tool body 1 "lacks a microcomputer," so the control parameters remain the power tool settings for power tools without a microcomputer, i.e., the default values. As shown in the first embodiment, these control parameters include overcurrent threshold, over-discharge voltage value, and upper limit value of battery cell temperature.

[0493] The current flowing through the battery cell 148 is monitored by the current detection circuit 327, which monitors the voltage across the shunt resistor 329. This voltage is then measured by the microcomputer included in the control unit 350. If the measured result indicates that the control parameter used for current monitoring exceeds the overcurrent threshold, the microcomputer in the control unit 350 sets the discharge inhibit signal 341 high, thereby stopping the rotation of the motor 35. Thus, instead of the protection IC 320 monitoring the current value, the microcomputer in the control unit 350 performs this monitoring, enabling various controls using the microcomputer.

[0494] Figure 27 This is a circuit diagram of the battery pack 100A according to the second embodiment of the present invention, showing its connection to an 18V power tool body 1A equipped with a microcomputer. In this diagram, the power tool body 1A shown on the left is connected to... Figure 20 The ones shown are exactly the same. Also, the battery pack 100A shown on the right is identical to... Figure 26 The conditions for overload protection in the control unit 350 are exactly the same. The switching of overload protection conditions is mainly based on the current limit value during discharge. When a battery pack 100A is installed in a conventional power tool body 1 without a microcomputer, the control unit 350 sets the current limit value to I. max The current is limited to around 20A. However, when the power tool body 1A includes a microcomputer, the current monitoring of the power tool body is performed by the microcomputer on the body side, thus eliminating the need to set a current limit value I by the control unit 350. max Therefore, the control unit 350 does not set a current limit value I. max Alternatively, it can be set to an upper limit value of the current that can be derived from the cell unit 148 (e.g., 60A). This upper limit value of the derivative current is not determined by the limitation on the power tool body 1A side, but depends on the performance of the battery cell. Thus, on the battery pack 100A side, it is no longer necessary to limit the capacity of the battery pack to the necessary level. Therefore, corresponding to battery packs where the current derivative becomes increasingly larger due to improvements in battery cell performance, the power tool body 1A side can maximize its capacity. Furthermore, since the conventional power tool body 1 is also subject to the same current limitation, a battery pack 100A with high compatibility and high reliability can be achieved. In addition, in the second embodiment, the switching of overload protection conditions is not limited to peak current value and average current value; cell temperature detection value, over-discharge voltage value, etc., can also be changed. Moreover, instead of setting thresholds for these values ​​and simply performing overload protection based on whether the threshold is exceeded, if the control unit 350 includes a microcomputer, overload protection can be performed by performing calculations using these parameters, and the calculation results will correspond to the overload protection. Control can be achieved by using an arithmetic expression to change the over-discharge voltage when the cell temperature is high and low. For example, the following control can also be performed: when the cell temperature is high, the over-discharge voltage threshold is increased; when the cell temperature is low, the over-discharge voltage threshold is decreased. If the monitoring result of the control unit 350 indicates that the power tool must be stopped, the control unit 350 sends a discharge prohibition signal 341 to the switching element M41, making the source-drain of the switching element M41 conduct. As a result, the LD terminal 28 on the power tool body 1A side becomes low, and the rotation of the motor 5 stops.

[0495] Example 3

[0496] Figure 28This is a perspective view of a battery pack 400 according to a third embodiment of the present invention. The battery pack 400 includes multiple connection terminals that engage with the contact ends of a charging device or tool body to achieve electrical conductivity. Each connection terminal comprises two connection terminal parts separated in the vertical direction, and the shape of the connection terminal parts is characteristic. The external shape of the battery pack 400 is substantially the same as that of the battery pack 100 shown in the first embodiment, with the only difference being that a locally raised stepped portion (see reference) is not formed on the upper section surface 415 of the upper housing 410. Figure 12 115a, 115b); and the corner on the left front side of the lower section 411 where no recess is formed (see reference). Figure 12 (111a). At the step portion connecting the upper section surface 415 and the lower section surface 111, a plurality of slots 420 are provided, but the width or size of the slots 420 is approximately the same as that of the battery pack 100 in the first embodiment. A raised portion 432 is formed on the rear side of the upper section surface, and latches 441 are provided on the left and right sides of the raised portion 432.

[0497] Inside the lower housing 401, ten battery cells 446 are housed. Here, an upper cell unit consisting of five cells connected in series and a lower cell unit are provided, with an output of rated 18V as the parallel connection of these cell units. That is, the battery pack 400 is a voltage-fixed type. Each connection terminal is formed by both an upper terminal part and a lower terminal part. Specifically, the positive terminal for charging includes an upper positive terminal 461 and a lower positive terminal 471, which are short-circuited. The positive terminal for discharging includes an upper positive terminal 462 and a lower positive terminal 472, which are short-circuited. Furthermore, the upper positive terminal 461 and the lower positive terminal 471, and the upper positive terminal 462 and the lower positive terminal 472, are connected via a self-controlled protector (not shown).

[0498] The negative terminal includes an upper negative terminal 467 and a lower negative terminal 477, which are connected. Because a single connection terminal is constructed by dividing it into two connection terminal parts, the number and total area of ​​the contact portions with the device-side terminal on the power tool body 1 are increased. This makes it less likely to cause problems such as overheating due to poor contact caused by vibration during operation of the power tool, enabling long-term stable use and thus extending the lifespan of the battery pack 400.

[0499] The signal terminals used for signal transmission in the connection terminals, namely the T terminal group (upper T terminal 464 and lower T terminal 474), the V terminal group (upper V terminal 465 and lower V terminal 475), the LS terminal group (upper LS terminal 466 and lower LS terminal 476), and the LD terminal group (upper LD terminal 468 and lower LD terminal 478), each also includes two terminals, and the upper and lower terminals are connected and set to the same potential. The upper connection terminals (461-462, 464-468) and the lower connection terminals (471-472, 474-478) are fixed to the circuit board 450. An IC for battery cell protection is mounted on the circuit board 450, but no microcomputer or LED for displaying the remaining battery power is provided.

[0500] Figure 29 yes Figure 28 A partial enlarged view of the connection terminals. Both the upper terminal parts (465-468) and the lower terminal parts (476-478) are roughly L-shaped in side view, and the feet of the upper and lower terminal parts are fixed to the circuit board 450 in a manner aligned with the mounting direction. The fixing method is... Figure 4 , Figure 5 The same method is used in the first embodiment shown, with the feet passing through the mounting holes of the circuit board 450 and soldered from the back side of the circuit board 450. Each upper terminal part (465-468) and lower terminal part (476-478) has a generally V-shaped fitting portion 478c formed, which narrows at intervals between the two side arms. In conventional battery packs, the fitting portion is arranged such that the generally V-shaped ridge portion is orthogonal to the insertion direction of the device-side terminal. That is, in conventional terminal parts, the ridge of the generally V-shaped ridge portion (e.g., the inner surface vertex portion shown in the fitting portion 478c) is formed with its ridge extending vertically. However, in this embodiment, the ridge extension direction is not vertical, but rather formed in an inclined manner, thus increasing the length of the contact portion with the plate-like body side end and the fitting portion of the terminal part.

[0501] Figure 30(1) is a perspective view of the upper terminal part 480. However, the foot of the upper terminal part 480 is omitted, and only the part located on the upper side of the circuit board 450 is shown. The upper terminal part 480 is formed by cutting a flat plate containing conductive metal through stamping, bending it into a U-shape, and forming a predetermined bending shape in the arm. Here, the bridge part 482, which forms the bottom of the U-shape, is bent in such a way that the bridge part 482 is on the rear side, and the right side surface 483 and the left side surface 484 are formed from the left and right sides of the bridge part 482 extending in the vertical direction towards the front side. The right side surface 483 and the left side surface 484 are formed in a symmetrical manner, and the right side surface 483 and the left side surface 484 are parallel surfaces with a fixed interval. Left and right arms 485 and 486 are formed from the upper front edges of the right side 483 and left side 484, respectively. The root portions of arms 485 and 486, i.e., flat portions 485a and 486a, are parallel planes in the left-right direction, aligned with the right side 483 and left side 484. Curved portions 485b and 486b, which bend inwards, are formed in front of the flat portions 485a and 486a. While the curved portions 485b and 486b are flat, the larger outward bends are arranged such that their ridge lines become inclined.

[0502] In front of the curved portions 485b and 486a, there are approximately V-shaped fitting portions 485c and 486c. The fitting portions 485c and 486c are convex inwards. During the installation of the battery pack 100, the convex portion on the inner side of the fitting portions 485c and 486c is the part that contacts and slides against the plate-shaped device-side terminals. Therefore, although it is approximately V-shaped, its apex (the convex portion) is composed of a large radius of curvature R1 or a small radius of curvature. This is to reduce the sliding resistance between the device-side terminals and the fitting portions 485c and 486c during sliding, and to increase the contact area with the fitting portions 485c and 486c to reduce contact resistance when not sliding and in contact. On the front side of the fitting portions 485c and 486c, guide portions 485d and 486d are connected, which guide plate-shaped device-side terminals to be inserted between the fitting portions 485c and 486c. The guide portions 485d and 486d are generally planar and expand laterally towards the front. Therefore, the front ends 485e and 486e of the arms 485 and 486 are positioned below the arms 485 and 486. The front ends 485e and 486e are rounded at the corners by depicting a small radius of curvature.

[0503] Figure 30Figure (2) is a diagram illustrating the positional relationship between the contact portions of fitting parts 485c and 486c and the device-side terminals. Only the left arm portion 486 is shown here, but the right arm portion 485 is simply symmetrical and has the same shape. The width W in the height direction of the arm portion 486 is fixed in the front-back direction, but the contact portion of fitting part 486c is located at the position shown by the thick line. The contact portion shown by the thick line is either a linear contact portion or a narrow rectangular contact area. The contact length of the contact portion shown by the thick line is W / cosθ times the length (=W) when fitting part 486c is formed on the vertical line. Thus, the long side direction of the contact portion or contact area of ​​fitting part 486c is arranged in a way that becomes inclined relative to the mounting direction of the device-side terminal on the contact surface with the device-side terminal, thereby increasing the contact portion or contact area and thus expanding the contact area with the device-side terminal on the power tool body side. As a result, the contact resistance between the device-side terminal and the mating portion 486c can be reduced, thereby effectively suppressing terminal heating caused by increased contact resistance. Furthermore, the generation of arcs between the device-side terminal and the device-side terminal can be suppressed, thus preventing damage or melting of the arms 485 and 486. Additionally, regarding the upper positive terminals 461 and 462 and the lower positive terminals 471 and 472, which serve as power terminals, the positive terminals of the upper cell unit 146 and the lower cell unit 147 can be connected respectively, similar to the first embodiment, making it suitable for battery packs that can switch between low-voltage and high-voltage sides in the same way as in the first embodiment. At this time, in the upper terminal component 200 described in the first embodiment (refer to...) Figure 5 ) and lower terminal part 220 (refer to Figure 5 The fitting portion can be any shape that fits the arm portion and the fitting portion of the third embodiment.

[0504] Regarding terminals used for signal transmission ( Figure 28 The upper terminal parts 464-466, 468 and the lower terminal parts 474-476, 478 are also configured to be formed by two interlocking upper and lower sections, which are set to the same potential to allow the same signal to flow. However, it is also possible to configure the upper and lower parts of the signal terminal to be set to different potentials, and the equipment side terminal on the power tool body side is also formed separately, thereby increasing the number of signals transmitted. Moreover, regarding the terminals for signal transmission, there is little need to use terminal parts that are completely separated upper and lower, so terminal parts that are connected upper and lower can also be formed. Next, by Figure 31 To illustrate the shape of the terminal part 500 that connects the upper and lower parts.

[0505] Figure 31This is a perspective view showing the shape of the terminal part 500. However, the feet of the terminal part 500 are omitted from the illustration; only the portion located on the upper side of the circuit board 450 is shown. The terminal part 500 forms an upper arm piece 506 and a lower arm piece 510 by forming a groove 508 that divides the right arm piece 505 vertically in approximately half of its front side. Similarly, an upper arm piece 507 and a lower arm piece 511 are formed by forming a groove 512 that divides the left arm piece 506 vertically in approximately half of its front side. Thus, by dividing the arm piece 506 and 507 into upper and lower arm pieces 510 and 511 by the grooves 508 and 512, a structure with two sets of arm pieces in one terminal part 500 can be achieved, thereby enabling a signal terminal that ensures a good mating state. The upper terminal group (506, 507) and the lower terminal group (510, 511) are respectively provided with fitting portions (506c, 507c) and fitting portions (510c, 511c) for fitting with the plate-shaped body-side connecting terminals (but in... Figure 31 (The mating parts 506c and 510c are not visible). The upper mating parts (506c and 507c) are arranged at an angle along the long side of the contact portion or contact area. Similarly, the lower mating parts (510c and 511c) are arranged at an angle along the long side of the contact portion or contact area. The long side directions of the contact portions or contact areas of the upper and lower mating parts are arranged in a row. Alternatively, the upper and lower mating parts can be arranged in the same position when viewed from the front-back direction, so that the long side directions of the contact portions or contact areas of the upper and lower mating parts are not arranged in a row. Moreover, the angles of the long side directions of the upper and lower mating parts can be different and set to opposite directions. For example, the shape of the upper arm assembly (506 and 507) can be changed to a shape that reverses the vertical direction of the lower terminal assembly (510 and 511), that is, a shape that is symmetrical with respect to the horizontal plane. As described above, the long side of the contact area of ​​the mating part is formed in an inclined direction rather than a vertical direction. As a result, compared with the conventional example where the mating part is orthogonal to the mounting direction, the length of the mating part can be increased, and thus the contact resistance can be reduced.

[0506] The shapes (480, 500) of the connection terminals for a voltage-fixed battery pack have been described above in the third embodiment, but these terminal shapes can also be applied to voltage-switching battery packs like those in the first embodiment. For example, they can also be used in... Figure 9 The signal terminal component 240 shown uses Figure 31 The configuration of the mating portion of the terminal part 500 shown.

[0507] The present invention has been described above based on embodiments, but the present invention is not limited to the embodiments described, and various modifications can be made within the scope of its spirit. For example, the embodiments described use a battery pack with a voltage switching capability of 18V and 36V, but the switching voltage ratio is not limited to this, and other voltage ratios can also be switched by a combination of series connection and parallel connection.

Claims

1. A battery pack having multiple battery cells, and capable of switching between outputs from series connection or parallel connection of the battery cells, wherein each battery cell is composed of multiple battery cells connected in series, the battery pack being characterized in that... A protection circuit for monitoring the state of the battery cell is provided for each of the aforementioned battery cell units. Only in the protection circuit of the lowest segment of the battery cell units connected in series with the ground wire side, a microcomputer is provided to input signals from the multiple protection circuits. A remaining capacity display component is provided and connected to the lowest cell unit, configured such that when the switch for displaying remaining power is operated, the remaining power of the battery pack is displayed based on a signal from the microcomputer.

2. The battery pack according to claim 1, characterized in that, Configure a power supply circuit to generate the power supply for driving the microcomputer. The power supply circuit generates the power from the output of the lowest segment of the battery cell unit connected to the ground wire side in the series connection.

3. The battery pack according to claim 2, characterized in that, The power supply circuit generates power for driving the remaining capacity display component.

4. The battery pack according to any one of claims 1 to 3, characterized in that, When the switch is operated, the microcomputer performs lighting control to display the remaining battery power through the remaining capacity display component.

5. The battery pack according to any one of claims 1 to 3, characterized in that, The remaining battery capacity is displayed based on the voltage across one of the multiple battery cells.

6. The battery pack according to any one of claims 1 to 3, characterized in that, The remaining battery capacity is displayed based on the lowest voltage value among the plurality of battery cells.

7. A first electrical device body, capable of being connected to the battery pack of any one of claims 1 to 3, characterized in that, include: motor; A battery pack mounting section for mounting the battery pack; as well as The contact tip is located at the battery pack mounting portion. When the battery pack is connected to the battery pack mounting part, it becomes a series connection state in which the battery cells are connected in series with each other via the contact end.

8. A second electrical device body, capable of being connected to the battery pack of any one of claims 1 to 3, characterized in that, include: motor; A battery pack mounting section for mounting the battery pack; as well as The contact tip is located at the battery pack mounting portion. When the battery pack is connected to the battery pack mounting part, it becomes a parallel connection state in which the battery cells are connected to each other in parallel via the contact end.

9. A battery pack having at least a first cell unit and a second cell unit as a cell unit formed by connecting a plurality of battery cells in series, and capable of switching between a series connection state and a connection state other than the series connection state, wherein the series connection state refers to connecting the first cell unit and the second cell unit in series with each other when the first cell unit is connected to a side with a higher voltage than the second cell unit, wherein... The battery pack includes: The control unit is directly or indirectly connected to the first cell unit and the second cell unit, and is capable of monitoring the state of the battery cells constituting the first cell unit and the state of the battery cells constituting the second cell unit, and outputting a control signal for controlling the discharge of the battery pack. A power supply circuit, which is connected to the control unit and is capable of supplying power voltage to the control unit; A housing, wherein the housing accommodates the first battery cell unit, the second battery cell unit, the control unit, and the power circuit, and is capable of connecting the battery pack to the main body of the electrical equipment; and The remaining capacity display component is configured to display the remaining battery power of the battery pack. The power supply circuit is connected only to the second battery cell in the first battery cell and the second battery cell. The control unit and the remaining capacity display component are connected to the negative terminal of the power supply circuit and the second battery cell. The power supply circuit generates the power supply voltage from the voltage input from the second battery cell and supplies it to the control unit and the remaining capacity display component.

10. The battery pack according to claim 9, characterized in that, It has a switch operated by the operator. When the switch is operated, the control unit performs lighting control to display the remaining battery power through the remaining capacity display component.

11. The battery pack according to claim 9 or 10, characterized in that, The remaining battery capacity is displayed based on the voltage across one of the multiple battery cells.

12. The battery pack according to claim 9 or 10, characterized in that, The remaining battery capacity is displayed based on the lowest voltage value among the plurality of battery cells.

13. A first electrical device body capable of being connected to the battery pack of claim 9 or 10, characterized in that, include: motor; A battery pack mounting section for mounting the battery pack; as well as The contact tip is located at the battery pack mounting portion. When the battery pack is connected to the battery pack mounting part, it becomes a series connection state in which the battery cells are connected in series with each other via the contact end.

14. A second electrical device body capable of being connected to the battery pack of claim 9 or 10, characterized in that, include: motor; A battery pack mounting section for mounting the battery pack; as well as The contact tip is located at the battery pack mounting portion. When the battery pack is connected to the battery pack mounting part, it becomes a parallel connection state in which the battery cells are connected to each other in parallel via the contact end.

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