battery pack

Abstract

The present application provides a battery pack capable of suppressing the influence of heat on electronic components on a substrate in the battery pack. The battery pack according to one aspect of the present application includes a battery, a substrate, a first connection terminal, a second connection terminal, a control circuit, and a bus bar. The first connection terminal is provided on the substrate and configured to be connectable to a power tool. The second connection terminal is provided on the substrate and connected to the battery. The control circuit is provided on the substrate and configured to control discharge of the battery. The bus bar is provided on the substrate and disposed in a discharge path between the first connection terminal and the second connection terminal.

Description

TECHNICAL FIELD

[0001] The present application relates to a battery pack. BACKGROUND

[0002] The battery pack described in Patent Document 1 has a multilayer substrate on which a microcomputer, a discharge terminal, a charge terminal, and a negative terminal, and the like are mounted. The battery pack is configured to connect the negative terminal to a negative electrode of a battery cell through a multilayer conductor pattern, thereby increasing a current capacity.

[0003] PRIOR ART DOCUMENT

[0004] PATENT DOCUMENT

[0005] Patent Document 1: Japanese Patent No. 6095502

[0006] When current flows through the negative terminal and the multilayer conductor pattern, the negative terminal and the multilayer conductor pattern generate heat. When the current capacity increases, the heat generated by the negative terminal and the multilayer conductor pattern increases. Since the negative terminal and the multilayer conductor pattern are mounted on the same substrate as electronic components such as the microcomputer, the heat generated by the negative terminal and the multilayer conductor pattern is transferred to the electronic components. When the current capacity increases, the amount of heat transferred to the electronic components increases, and thus the electronic components can be affected by the heat.

[0007] One aspect of the present application provides a battery pack that can suppress heat from affecting electronic components on a substrate in the battery pack. SUMMARY

[0008] One aspect of the present application is a battery pack including a battery, a substrate, a first connection terminal, a second connection terminal, a control circuit, and a bus bar. The first connection terminal is provided on the substrate and configured to be connected to a power tool. The second connection terminal is provided on the substrate and connected to the battery. The control circuit is provided on the substrate and configured to control discharge of the battery. The bus bar is provided on the substrate and disposed in a discharge path between the first connection terminal and the second connection terminal.

[0009] According to one aspect of the present application, a bus bar is provided in the discharge path between the first connection terminal and the second connection terminal, and heat generated by the first connection terminal is transferred to the bus bar while the discharge current flows through the bus bar. The bus bar has a larger cross-sectional area than the conductor pattern, and thus has a smaller resistance value, so that the amount of heat generated by the current flow is suppressed. In addition, the bus bar has a large conductor volume, and thus has a higher heat storage capacity than the conductor pattern. Furthermore, by providing the bus bar, the conductor pattern can be saved, and thus the transfer of heat from the heat generating component to the electronic component via the conductor pattern can be suppressed. Therefore, by providing the bus bar in the discharge path, the amount of heat transferred to the electronic component such as the control circuit can be reduced, and thus the influence of heat on the electronic component such as the control circuit can be suppressed. In addition, the bus bar is a component having a higher strength than the substrate. Thus, by providing the bus bar on the substrate, the warping of the substrate can be suppressed, and the structure of the substrate can be strengthened.

[0010] In addition, on the substrate, an element having a resistance component provided in the discharge path can be further provided. The element having a resistance component generates heat by the flow of the discharge current, and the heat is transferred to the bus bar and released therefrom. Accordingly, the transfer of heat generated by the element having a resistance component to the electronic component such as the control circuit can be favorably suppressed.

[0011] In addition, the bus bar can include a plurality of standing portions standing from the substrate, and a non-contact portion connecting the plurality of standing portions, and a gap can be provided between the substrate and the non-contact portion.

[0012] By the non-contact portion of the bus bar not contacting the substrate, the transfer of heat from the bus bar to the control circuit and the like can be further suppressed.

[0013] In addition, the bus bar can include a shunt resistor.

[0014] By the bus bar including the shunt resistor, the number of components on the substrate can be reduced. Furthermore, the substrate can be miniaturized.

[0015] In addition, a housing and a heat sink can be further provided. The housing accommodates the battery and the substrate. The heat sink is provided in contact with the inner surface of the housing and the surface of the bus bar.

[0016] By providing the heat sink, the impact applied to the housing can be suppressed from being transferred to the substrate, and the release of heat from the bus bar can be further promoted. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a side view showing a battery system including a battery pack according to the present embodiment and an electric working machine.

[0018] Figure 2is a perspective view showing a machine connecting portion of an electric power machine involved in the present embodiment.

[0019] Figure 3 is a perspective view showing a battery connecting portion of a battery pack involved in the present embodiment.

[0020] Figure 4 is a plan view showing an upper case of the battery pack involved in the present embodiment.

[0021] Figure 5 is a plan view showing a substrate of the battery pack involved in the present embodiment.

[0022] Figure 6 is a side view showing the substrate of the battery pack involved in the present embodiment.

[0023] Figure 7 is a view showing a circuit configuration of the battery pack involved in the present embodiment.

[0024] Figure 8 is a side view showing a substrate of a battery pack involved in another embodiment.

[0025] Explanation of Reference Numerals

[0026] 10…substrate, 11…battery positive terminal, 12…battery negative terminal, 13…charging terminal, 14…first communication terminal, 15…serial communication terminal, 16…second communication terminal, 18…bus bar, 18a…rising portion, 18b…non-contact portion, 60…battery, 60a…positive tab, 60b…negative tab, 67…shunt resistor, 67a…first resistor, 67b…second resistor, 67c…third resistor, 81…SCP circuit, 81a…first SCP circuit, 81b…second SCP circuit, 100…battery pack, 101…positive line, 102…negative line, 110…battery connecting portion, 111…first insertion opening, 112…second insertion opening, 113…third insertion opening, 114…fourth insertion opening, 120…upper case, 130…lower case, 185…heat sink, 500…electric power machine, 610…AFE, 620…MPU. DETAILED DESCRIPTION

[0027] Hereinafter, modes for carrying out the present application will be described with reference to the drawings.

[0028] <1. Configuration of Battery System>

[0029] First, with respect to the configuration of the battery system involved in the present embodiment, reference will be made to Figures 1-3An explanation will be given. The battery system according to the present embodiment is provided with a battery pack 100 and an electric working machine 500. The battery pack 100 supplies electric power to the electric working machine 500. The electric working machine 500 is operated by receiving the supply of electric power from the battery pack 100.

[0030] In the present embodiment, the electric working machine 500 is an impact driver, but the electric working machine 500 is not limited to an impact driver. The electric working machine 500 is not particularly limited as long as it is a working machine that can be operated by receiving the supply of electric power from the battery pack 100, and can be, for example, an electric power tool such as an impact driver or a hammer drill, or a garden tool such as a lawn mower or a hedge trimmer, a laser marker, a lamp, or the like.

[0031] The electric working machine 500 is provided, at a lower portion of a grip portion held by a user, with a machine connection portion 50 that connects the battery pack 100. As shown in Figure 2 the machine connection portion 50 is provided with four terminals that protrude from a rectangular connection surface toward the battery pack 100. The four terminals are plate-shaped terminals made of metal and extend in the length direction of the machine connection portion 50. Specifically, the machine connection portion 50 is provided with a machine positive terminal 51, a machine first communication terminal 53, a machine second communication terminal 54, and a machine negative terminal 52. The machine positive terminal 51, the machine first communication terminal 53, the machine second communication terminal 54, and the machine negative terminal 52 are arranged side by side in the short side direction of the machine connection portion 50 in this order. The machine positive terminal 51 and the machine negative terminal 52 are longer than the machine first communication terminal 53 and the machine second communication terminal 54.

[0032] The battery pack 100 is provided with an upper case 120 and a lower case 130. The upper case 120 is a tray-shaped case having an open lower surface. The lower case 130 is a rectangular case having an open upper surface. The upper case 120 covers the open upper surface of the lower case 130, and one case is configured by combining the upper case 120 and the lower case 130 together. Inside the upper case 120 and the lower case 130, a substrate 10 and a battery 60 described later are housed.

[0033] The upper case 120 is provided, on an upper surface, with a battery connection portion 110 that connects the machine connection portion 50. As shown in Figure 3As shown, the battery connecting portion 110 has four insertion openings into which the four terminals of the working machine connecting portion 50 are inserted. The four insertion openings extend along the length direction of the upper case 120. Specifically, the battery connecting portion 110 has a first insertion opening 111, a third insertion opening 113, a fourth insertion opening 114, and a second insertion opening 112. The first insertion opening 111, the third insertion opening 113, the fourth insertion opening 114, and the second insertion opening 112 are arranged side by side in the short side direction of the upper case 120 in this order.

[0034] The first insertion opening 111 is provided with the battery positive electrode terminal 11 made of metal, which will be described later, and the working machine positive electrode terminal 51 is inserted into the first insertion opening 111. The second insertion opening 112 is provided with the battery negative electrode terminal 12 made of metal, which will be described later, and the working machine negative electrode terminal 52 is inserted into the second insertion opening 112. The third insertion opening 113 is provided with the charging terminal 13 and the first communication terminal 14 made of metal, which will be described later, and the working machine first communication terminal 53 is inserted into the third insertion opening 113. The fourth insertion opening 114 is provided with the serial communication terminal 15 and the second communication terminal 16 made of metal, which will be described later, and the working machine second communication terminal 54 is inserted into the fourth insertion opening 114.

[0035] In a state in which the working machine connecting portion 50 and the battery connecting portion 110 are opposed to each other, the working machine connecting portion 50 is connected to the battery connecting portion 110 by sliding the electric working machine 500 relative to the battery pack 100. Accordingly, the working machine positive electrode terminal 51 is connected to the battery positive electrode terminal 11, and the working machine negative electrode terminal 52 is connected to the battery negative electrode terminal 12. In addition, the working machine first communication terminal 53 is connected to the first communication terminal 14, and the working machine second communication terminal 54 is connected to the second communication terminal 16. Furthermore, electric power can be supplied from the battery pack 100 to the electric working machine 500, and communication can be performed between the battery pack 100 and the electric working machine 500. In this state, the electric working machine 500 is activated as soon as the user pulls the trigger switch of the electric working machine 500.

[0036] <2. Base plate of battery pack>

[0037] <2-1. Overall configuration of base plate>

[0038] Next, the overall configuration of the base plate 10 of the battery pack 100 will be described with reference to FIG. 1. Figures 4-7 Figure 4 indicates a state in which the upper case 120 is detached from the battery pack 100. Figure 5 and Figure 6 indicates the base plate 10 detached from the battery pack 100. Figure 7 indicates the circuit configuration of the battery pack 100. ​

[0039] like Figure 4 As shown, a substrate 10 is disposed below the upper housing 120 of the battery pack 100. Furthermore, a battery 60 is housed in the space between the substrate 10 and the lower housing 130. The battery 60 includes multiple battery cells connected in series, such as lithium-ion batteries, and is a battery capable of discharging and charging.

[0040] Substrate 10 is a rectangular printed circuit board. For example... Figure 4 as well as Figure 5 As shown, the following components are mounted on the substrate 10: a positive terminal 11 for the battery, a negative terminal 12 for the battery, a charging terminal 13, a first communication terminal 14, a serial communication terminal 15, a second communication terminal 16, an analog front end (AFE) 610, a microprocessor unit (MPU) 620, a self-control protector (SCP) circuit 81, a shunt resistor 67, and a bus 18. Furthermore, as... Figure 7 As shown, the substrate 10 includes a current detection circuit 63, a battery pack voltage detection unit 66, a power supply circuit 70, and a sub-printed circuit board control unit (hereinafter referred to as the sub-PCB control unit) 90. Additionally, a positive electrode tab 60a and a negative electrode tab 60b are provided on the substrate 10.

[0041] When the charger is connected to the battery pack 100, the charging terminal 13 outputs a charging permission signal or a charging prohibition signal to the charger. The charging permission signal allows charging of the battery 60. The charging prohibition signal prohibits charging of the battery 60. When the electric work machine 500 is connected to the battery pack 100, trigger switch information is input from the electric work machine 500 to the first communication terminal 14. The trigger switch information indicates whether the trigger switch of the electric work machine 500 is on or off. When the charger is connected to the battery pack 100, the serial communication terminal 15 is used for serial communication with the charger.

[0042] When the electric work machine 500 is connected to the battery pack 100, the second communication terminal 16 outputs a discharge permission signal or a discharge prohibition signal to the electric work machine 500. The discharge permission signal allows discharge from the battery 60. The discharge prohibition signal prohibits discharge from the battery 60. Additionally, when the MPU 620 is powered off and the charger is connected to the battery pack 100, auxiliary power is supplied from the charger to the second communication terminal 16.

[0043] like Figure 7As shown, the positive terminal 11 of the storage battery is connected to the positive tab 60a via the positive line 101. The positive tab 60a is connected to the positive electrode 61a of the storage battery 60. In addition, the negative terminal 12 of the storage battery is connected to the negative tab 60b via the negative line 102. The negative tab 60b is connected to the negative electrode 61b of the storage battery 60.

[0044] The MPU 620 includes a microcomputer having a CPU, a ROM, a RAM, an I / O, and the like, and performs various controls including discharge control and charge control of the storage battery 60. The MPU 620 acquires the information of the trigger switch of the power tool 500 via the second communication terminal 16. The MPU 620 performs wake-up when the information of the on of the trigger switch is acquired, and performs transition to the sleep mode when the information of the off of the trigger switch is acquired and a prescribed condition is satisfied.

[0045] The AFE 610 is an analog circuit configured to be able to perform at least one of the following (1) to (6).

[0046] (1) Detects the cell voltage of each storage battery cell included in the storage battery 60 according to the instruction from the MPU 620.

[0047] (2) Detects the cell temperature of at least one storage battery cell via the thermistor 68.

[0048] (3) Performs cell balancing processing for equalizing the remaining capacities of a plurality of storage battery cells.

[0049] (4) Detects the substrate temperature via the thermistor 65.

[0050] (5) Detects the charge current flowing into the storage battery 60 and the discharge current flowing out of the storage battery 60 via the shunt resistor 67.

[0051] (6) Converts the detected values of the cell voltage, the cell temperature, the substrate temperature, and the charge / discharge current into digital signals, and outputs each of the converted digital signals to the MPU 620.

[0052] The MPU 620 determines the state of the storage battery 60 based on the input various signals. Also, the MPU 620 determines whether to permit or prohibit charging of the storage battery 60 based on the determined state of the storage battery 60, and generates a charge permission signal or a charge prohibition signal, and outputs it to the charge terminal 13. In addition, the MPU 620 determines whether to permit or prohibit discharging from the storage battery 60 based on the determined state of the storage battery 60, and generates a discharge permission signal or a discharge prohibition signal, and outputs it to the second communication terminal 16.

[0053] The current detection circuit 63 detects the current flowing out of or into the battery 60 by means of a shunt resistor 67. The battery pack voltage detection section 66 detects the voltage between the two terminals of the battery 60, i.e., the battery pack voltage, and outputs the detected battery pack voltage to the MPU 620. The MPU 620 determines whether the sum of the battery voltage detected by the battery pack voltage detection section 66 and the cell voltage detected by the AFE 610 is consistent.

[0054] The power supply circuit 70 is provided with a switch 72 and a regulator 73. When the MPU 620 is powered off, the regulator 73 receives the supply of the auxiliary power from the charger via the second communication terminal 16 and generates a power supply voltage VDD for driving the internal circuit. The battery pack 100 is powered off when it is in the overdischarged state. When the MPU 620 receives the supply of the power supply voltage VDD generated by the regulator 73, it is started from the powered-off state, and if the battery is in a state in which it can be charged, a charging permission signal is output to the charger. When the battery voltage reaches a prescribed voltage, the switch 72 is turned on. Once the switch 72 is turned on, the regulator 73 receives the supply of power from the battery 60 and generates the power supply voltage VDD.

[0055] The sub-PCB control section 90 is provided with an LED and a switch. Once the MPU 620 detects that the switch is pressed, the LED is lit according to the remaining capacity of the battery. The remaining capacity of the battery can be calculated from the battery voltage, from the cumulative value of the current, or from both.

[0056] The SCP circuit 81 includes two circuits, a first SCP circuit 81a and a second SCP circuit 81b, and is provided on the positive line 101. The first SCP circuit 81a includes a resistor and a fuse. The second SCP circuit 81b is configured similarly to the first SCP circuit 81a. The SCP circuit 81 can be provided with either one of the first SCP circuit 81a and the second SCP circuit 81b, or three or more SCP circuits.

[0057] In order to ensure safety, even in the case where charging does not stop even if the charging prohibition signal is output, and in the case where discharging does not stop even if the discharging prohibition signal is output from the battery pack 100, the MPU 620 causes current to flow through the resistors of the first SCP circuit 81a and the second SCP circuit 81b to fuse the fuses. Thereby, the positive line 101 is broken, and the battery 60 becomes in a state in which it cannot be charged or discharged. That is, the battery 60 becomes in a state in which it cannot be reused. The SCP circuit 81 is a circuit for taking double insurance against the overcharged state and the overdischarged state of the battery 60.

[0058] Busbar 18 and shunt resistor 67 are disposed on negative line 102. The shunt resistor 67 includes a first resistor 67a, a second resistor 67b, and a third resistor 67c. The first resistor 67a, the second resistor 67b, and the third resistor 67c are connected in parallel. That is, in this embodiment, the charging current and the discharging current are shunted to the three resistors 67a, 67b, and 67c for detection. The shunt resistor 67 may consist of one resistor, two resistors connected in parallel, or four or more resistors connected in parallel.

[0059] <2-2. Component Configuration on the Substrate>

[0060] Next, the arrangement of the main components on the substrate 10 will be described. Hereinafter, Figure 4 The top and bottom of the paper are referred to as top and bottom, and the left and right sides are referred to as left and right. The substrate 10 is configured such that the width of the right end is greater than that of the left end. When the electric work machine 500 slides from left to right, it will be mounted on the battery pack 100.

[0061] At the lower end of the substrate 10, a positive electrode tab 60a is disposed on the left side. At the lower end of the substrate 10, a negative electrode tab 60b is disposed on the right side.

[0062] The first SCP circuit 81a and the second SCP circuit 81b included in SCP circuit 81 are located on the upper left side of the substrate 10. The first SCP circuit 81a and the second SCP circuit 81b are arranged side by side, one above the other.

[0063] The positive terminal 11, negative terminal 12, charging terminal 13, first communication terminal 14, serial communication terminal 15, and second communication terminal 16 of the battery are arranged side by side on the right side of the positive tab 60a.

[0064] Specifically, the positive terminal 11 of the battery extends in a left-right direction and is disposed at the upper end of the substrate 10. The charging terminal 13 and the first communication terminal 14 are disposed side-by-side below the positive terminal 11. The charging terminal 13 is located on the right side, and the first communication terminal 14 is located on the left side. The serial communication terminal 15 and the second communication terminal 16 are disposed side-by-side below the charging terminal 13 and the first communication terminal 14. The serial communication terminal 15 is located on the left side, and the second communication terminal 16 is located on the right side. Below the serial communication terminals 15 and the second communication terminal 16, the negative terminal 12 of the battery extends in a left-right direction and is disposed at the lower end of the substrate 10.

[0065] On the right side of the substrate 10, the first resistor 67a, the second resistor 67b, and the third resistor 67c included in the shunt resistor 67 are arranged side by side in the vertical direction above the negative electrode tab 60b.

[0066] Bus bar 18 is provided between battery negative terminal 12 and shunt resistor 67. As shown in FIG. 6, bus bar 18 has two standing portions 18a and a non-contact portion 18b. Each standing portion 18a stands in the vertical direction from substrate 10. A first end of each standing portion 18a is soldered to substrate 10. One of the two standing portions 18a is disposed in a position close to battery negative terminal 12. The other of the two standing portions 18a is disposed in the vicinity of shunt resistor 67. Figure 6

[0067] Non-contact portion 18b connects second ends of the two standing portions 18a and extends in the left-right direction of substrate 10. In detail, non-contact portion 18b is disposed so that its extending direction is parallel to the edge of the lower side of substrate 10. Non-contact portion 18b floats above substrate 10 without contacting substrate 10. That is, a gap corresponding to the length of standing portion 18a is provided between non-contact portion 18b and substrate 10. The length of standing portion 18a is formed so that, in a case where upper case 120 covers substrate 10, a gap is provided between non-contact portion 18b and upper case 120. By providing a gap between non-contact portion 18b and upper case 120, in a case where upper case 120 contacts an object, it is possible to suppress the transmission of an impact to non-contact portion 18b and even to substrate 10.

[0068] MPU 620 is disposed on the right side of charging terminal 13 and serial communication terminal 15 at a prescribed distance therefrom, and is disposed on the upper side of bus bar 18 at a prescribed distance therefrom. AFE 610 is disposed on the right side of MPU 620 at a prescribed distance therefrom, and is disposed on the upper side of bus bar 18 at a prescribed distance therefrom.

[0069] In addition, in the left-right direction, MPU 620 and AFE 610 are disposed between the left end portion and the right end portion of non-contact portion 18b. That is, the left end portion of MPU 620 is disposed at a position further to the right than the left end portion of non-contact portion 18b. The right end portion of AFE 610 is disposed at a position further to the left than the right end portion of non-contact portion 18b.

[0070] In addition, as shown in FIG. 6, in the up-down direction, MPU 620 is disposed so as to straddle center line CL. AFE 610 is disposed at a position further to the upper side than center line CL, and bus bar 18 is disposed at a position further to the lower side than center line CL. Center line CL is a line passing through the center in the up-down direction of substrate 10. Figure 5

[0071] ​​When the work machine connecting portion 50 is connected to the battery connecting portion 110, a discharge current flows from the positive electrode tab 60a to the battery positive terminal 11 via the SCP circuit 81. Also, the discharge current flows from the battery positive terminal 11 to the battery negative terminal 12 via the electric work machine 500. Further, the discharge current flows from the battery negative terminal 12 to the negative electrode tab 60b via the bus bar 18 and the shunt resistor 67.

[0072] Here, when a current flows through an element having a resistance component (hereinafter referred to as a heat generating element), the element generates heat. In particular, since the current value of the discharge current is larger than that of the charge current by one digit or more, the amount of heat generated by the element becomes large. Among the electronic components on the substrate 10, the battery positive terminal 11, the battery negative terminal 12, the SCP circuit 81, the shunt resistor 67, and the bus bar 18 belong to the heat generating elements.

[0073] In most cases, a cooling fan is provided inside the electric work machine 500. Thus, in the electric work machine 500, the influence of heat generated by the heat generating elements on the electronic components of the control circuit and the like can possibly be reduced.

[0074] In this regard, in the battery pack 100, the heat generating elements are mounted on the same substrate 10 as the MPU 620 and the AFE 610. Also, in order to downsize the battery pack 100, no cooling fan is provided inside the battery pack 100. Thus, the MPU 620 and the AFE 610 on the substrate 10 can easily be affected by heat generated by the heat generating elements. Once the temperature of the MPU 620 and the AFE 610 is affected by the heat and exceeds the allowable temperature value, the operation of the MPU 620 and the AFE 610 can possibly be hindered.

[0075] The MPU 620 and the AFE 610 can be affected by heat generated by the heat generating elements disposed particularly in the vicinity of the MPU 620 and the AFE 610. In the present embodiment, the heat generating element disposed in the vicinity of the MPU 620 and the AFE 610 is a wiring connecting the battery negative terminal 12 and the shunt resistor 67.

[0076] Since the copper foil pattern is thin, the cross-sectional area is also small, and thus the resistance component is large, and the amount of heat generated is also large. Accordingly, in the case where the above-described wiring is configured using a conductor pattern (specifically, a copper foil pattern), the amount of heat generated in the battery negative terminal 12, the shunt resistor 67, and the copper foil pattern becomes large.

[0077] Further, since the copper foil pattern has a high thermal conductivity, it is susceptible to heat generated by the battery negative terminal 12 and the shunt resistor 67. Thus, when the wiring of the copper foil pattern is arranged in the vicinity of the MPU 620 and the AFE 610, the heat of the large amount of heat generated in the battery negative terminal 12, the shunt resistor 67, and the copper foil pattern is not so much released but transferred from the copper foil pattern to the MPU 620 and the AFE 610. As a result, the amount of heat transferred to the MPU 620 and the AFE 610 becomes large.

[0078] To this end, in the present embodiment, the battery negative terminal 12 is connected to the shunt resistor 67 via the bus bar 18. Further, the bus bar 18 is arranged in the vicinity of the MPU 620 and the AFE 610. The bus bar 18 is thicker and has a larger cross-sectional area than the copper foil pattern, and thus has a smaller resistance component and a smaller amount of heat generation.

[0079] Further, by mounting the bus bar 18, the copper foil pattern can be saved, and thus it is possible to suppress the case where the heat generated by the battery negative terminal 12 or the shunt resistor 67 is transferred to the MPU 620 and the AFE 610 via the copper foil pattern. In addition, the non-contact portion 18b of the bus bar 18 does not contact the substrate 10, and a gap is provided between the non-contact portion 18b and the substrate 10. Thus, compared to the case where the entire bus bar 18 contacts the substrate 10, the distance over which the heat is transferred from the bus bar 18 to the MPU 620 and the AFE 610 becomes longer. Accordingly, compared to the case where the entire bus bar 18 contacts the substrate 10, the heat is less likely to be transferred to the MPU 620 and the AFE 610.

[0080] Thus, in the present embodiment, it is possible to suppress the heat generation effect of the conductor pattern, and also to suppress the case where the heat generated by the battery negative terminal 12 and the shunt resistor 67 is transferred to the MPU 620 and the AFE 610.

[0081] In addition, the bus bar 18 is configured by a member having a higher strength than the substrate 10, and extends in the length direction of the substrate 10. Thus, by mounting the bus bar 18, it is possible to suppress the warping of the substrate 10, and to reinforce the configuration of the substrate 10.

[0082] In addition, the bus bar 18 can be integrally configured with the shunt resistor 67 using the same plate thickness. That is, the bus bar 18 can include the shunt resistor 67.

[0083] <3. Effects>

[0084] According to the above-described first embodiment, the following effects can be obtained.

[0085] (1) By providing a busbar 18 on the discharge path between the negative terminal 12 of the battery and the negative tab 60b, the amount of heat transferred to the MPU620 and AFE610 can be reduced, thereby suppressing the effect of heat on the MPU620 and AFE610. In addition, by providing the busbar 18 on the substrate 10, warping of the substrate 10 can be suppressed, and the structure of the substrate 10 can be strengthened.

[0086] (2) By providing a shunt resistor 67 in the discharge path between the negative terminal 12 of the battery and the negative tab 60b, the heat generated by the shunt resistor 67 is transferred to the bus 18 and released from the bus 18. Accordingly, the transfer of heat generated by the shunt resistor 67 to the MPU620 and AFE610 can be effectively suppressed.

[0087] (3) Since the non-contact portion 18b of the busbar 18 does not contact the substrate 10, the heat transfer from the busbar 18 to the MPU620 and AFE610 can be further suppressed.

[0088] (4) When the busbar 18 and the shunt resistor 67 are integrally constructed, the number of components on the substrate 10 can be reduced. Furthermore, the substrate 10 can be miniaturized.

[0089] (Other implementation methods)

[0090] While the above description illustrates the methods for implementing the present invention, the present invention is not limited to the above-described embodiments and can be implemented in various modifications.

[0091] (a) In the above embodiment, although a gap is provided between the surface of the busbar 18 and the upper housing 120, the present invention is not limited thereto. Figure 8 As shown, a heat sink 185 can also be provided on the busbar 18. The heat sink 185 is configured to contact the surface of the busbar 18 and the inner surface of the upper housing 120. The heat sink 185 is made of silicon, for example. Impacts applied to the upper housing 120 are absorbed by the heat sink 185, thereby suppressing the transmission of impacts to the substrate 10. In addition, the heat sink 185 can further promote the dissipation of heat from the busbar 18.

[0092] (b) In the above embodiment, although various terminals, SCP circuit 81, and shunt resistor 67 are provided on the substrate 10 as resistive components, the resistive components are not limited to these. For example, a field-effect transistor (hereinafter referred to as FET) may also be provided on the substrate 10 as a resistive component. FETs may also be provided on the positive line 101 and / or the negative line 102 to enable the blocking of charging current or discharging current.

[0093] (c) In the above embodiment, although the bus bar 18 is provided on the negative electrode line 102, the bus bar 18 can be provided on the positive electrode line 101, and the bus bar 18 can be provided on both the negative electrode line 102 and the positive electrode line 101. The bus bar 18 can be provided on a line disposed in the vicinity of the MPU 620 and the AFE 610, as long as the configuration of the components on the substrate 10 is taken into consideration.

[0094] (d) A plurality of functions possessed by one component in the above embodiment can be implemented by a plurality of components, or one function possessed by one component can be implemented by a plurality of components. Also, a plurality of functions possessed by a plurality of components can be implemented by one component, or one function implemented by a plurality of components can be implemented by one component. Also, a part of the configuration of the above embodiment can be omitted. Also, at least a part of the configuration of the above embodiment can be added to the configuration of another above embodiment, or at least a part of the configuration of the above embodiment can be replaced with the configuration of another above embodiment.

Claims

1. A battery pack, comprising: Storage battery; substrate; The first connection terminal is disposed on the substrate and configured to be connected to the electric work machine; The second connection terminal is disposed on the substrate and connected to the battery. A control circuit, disposed on the substrate, is configured to control the discharge of the battery; and A busbar, which has a discharge path disposed on the substrate between the first connection terminal and the second connection terminal. The busbar has two upright sections and a non-contact section. The two upright portions stand vertically from the substrate. A gap is provided between the substrate and the non-contact portion, the non-contact portion having a first edge portion and a second edge portion that extend in a straight line from one of the two raised portions to the other.

2. The battery pack according to claim 1, characterized in that, The substrate also includes an element having a resistive component disposed in the discharge path.

3. The battery pack according to claim 1 or 2, characterized in that, The busbar includes a shunt resistor.

4. The battery pack according to claim 1 or 2, characterized in that, The battery pack includes: A housing that houses the battery and the substrate; and A heat sink is configured to contact the inner surface of the housing and the surface of the busbar.

Images