Housing for battery pack and battery pack

Abstract

The present invention addresses the problem of providing: a housing 400 for a battery pack 40, said housing 400 being capable of suppressing the effect on components within the housing 400 even when an increase in internal pressure in the housing 400 has occurred; and the battery pack 40. In order to solve said problem, the housing 400 for the battery pack 40 installed in a hybrid system 10 comprises: a housing body 410 that has a first accommodating portion 411 which accommodates a battery module 50 which supplies power to a motor generator 2 of the hybrid system 10, and a second accommodating portion 412 which accommodates a control circuit for the battery module 50; a housing cover 420 that is attached to the housing body 410; and a partitioning wall part 415 that is provided between the first accommodating portion 411 and the second accommodating portion 412 in the housing body 410 and that divides the space of the first accommodating portion 412 and the space of the second accommodating portion 412 from each other.

Description

Battery pack housing and battery pack

[0001] The present invention relates to a housing for a battery pack mounted in a hybrid system and to a battery pack.

[0002] Patent Document 1 discloses a battery mounting structure for use in electric vehicles and hybrid vehicles. This battery mounting structure includes a case that houses multiple battery modules for driving the vehicle, located below a floor panel of a vehicle interior. The multiple battery modules are divided into lower and upper modules. The case includes a metal lower case member, a metal middle case member, and an upper case member that covers a predetermined area of ​​the upper surface of the middle case member from above. The lower module is fixed to the bottom of the lower case member, and the middle case member is fixed to the lower case member so as to cover the lower module from above, thereby watertightly housing the lower module. The upper module is fixed in a state of intimate contact with the upper surface of the middle case member within a predetermined area. The upper case member is formed in a container shape with an opening at its bottom, covers the predetermined area, and is fixed in a state where the periphery of the opening is in close contact with the upper surface of the middle case member, thereby watertightly housing the upper module. The lower case member is then attached to the underside of the floor panel, thereby fixing the case to the vehicle.

[0003] Patent Literature 2 discloses a battery pack device for use in, for example, an electric vehicle, which is composed of batteries stacked in multiple layers. The battery pack device includes a first battery group consisting of multiple batteries arranged on the same plane, and a second battery group consisting of multiple batteries identical to the first battery group arranged on the same plane within the battery tray, sandwiched between the first battery group and the second battery group. The battery pack includes a battery unit in which the batteries are electrically connected to each other, and a main body case that houses the battery unit. The batteries are rectangular parallelepiped and can be installed in a first position in which the height in the direction in which the second battery group overlaps the first battery group is small, and a second position in which the positions of the battery terminals in the direction in which they overlap are higher than those in the first position. This battery pack device is characterized in that a first battery of a first battery group is arranged in a second position, a hole is formed in the battery tray through which the vicinity of the terminal of the first battery passes, allowing the terminal of the first battery to come out toward the second battery group, a second battery of the second battery group near the hole is arranged in the first position, and the first battery and the second battery are electrically connected to each other by a connecting member having a fixed shape.

[0004] A battery pack housing contains many battery cells. These battery cells are typically lithium-ion or nickel-metal hydride batteries. Each battery cell is equipped with a valve (safety valve) to release gas if the internal pressure increases due to abnormal gas generation inside the cell. Because the battery pack housing is watertight, if an abnormality occurs in a battery cell inside the housing, the valve of that cell will activate and release gas, causing a sudden increase in the internal pressure of the housing. Since the housing also contains components such as control circuits, wiring, and connectors in addition to the battery cells, it is desirable to suppress the impact of an increase in the internal pressure of the housing on these components.

[0005] The battery pack housing contains the number of battery cells required to obtain the desired voltage. These battery cells are lithium-ion batteries or nickel-metal hydride batteries. The battery cells are arranged in a roughly rectangular parallelepiped shape, with multiple battery cells arranged in the limited space within the housing. Because the battery cells generate heat due to chemical reactions during charging and discharging, it is important to efficiently dissipate the heat emitted from the battery cells housed in a sealed state within the housing.

[0006] JP 2020-001451 A JP 2006-080042 A

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a battery pack housing and a battery pack that can suppress the effects on components inside the housing even when an internal pressure rise occurs in the housing, and also aims to provide a battery pack that can efficiently release heat from the battery cells to the outside.

[0008] A first aspect of the present invention is a housing for a battery pack to be mounted on a hybrid system, comprising: a housing main body having a first storage section that stores a battery module that supplies power to a motor generator of the hybrid system and a second storage section that stores a control circuit for the battery module; a housing cover attached to the housing main body; and a partition section provided between the first storage section and the second storage section in the housing main body, separating the space of the first storage section from the space of the second storage section.

[0009] A second aspect of the present invention is a battery pack mounted on a hybrid system, comprising: a battery module that supplies power to a motor generator of the hybrid system; a control circuit that controls the battery module; and a housing that accommodates the battery module and the control circuit, wherein the housing has a housing main body having a first storage section that accommodates the battery module and a second storage section that accommodates the control circuit, a housing cover attached to the housing main body, and a partition section provided between the first storage section and the second storage section of the housing main body, and the control circuit includes a BMU (Battery Management Unit) that controls the overall voltage of the battery module.

[0010] A third aspect of the present invention is a battery pack mounted on a hybrid system, comprising: a battery module that supplies power to a motor generator of the hybrid system; a control circuit that controls the battery module; a housing that accommodates the battery module and the control circuit; and an insulating heat-conducting member that is provided between the battery module and the housing.

[0011] According to the present invention, it is possible to provide a battery pack housing and a battery pack that can suppress the effects on components inside the housing even when an internal pressure rise occurs in the housing, and also to provide a battery pack that can efficiently release heat from the battery cells to the outside.

[0012] 7 is a block diagram showing a hybrid system. FIG. 8 is an external perspective view illustrating a battery pack according to the present embodiment. FIG. 9 is a partially exploded perspective view illustrating a battery pack according to the present embodiment. FIG. 10 is an external perspective view illustrating a housing main body of the housing according to the present embodiment. FIG. 11 is an external perspective view illustrating a housing cover of the housing according to the present embodiment. FIG. 12 is a schematic cross-sectional view illustrating a battery pack using the housing according to the present embodiment. FIG. 13 is an enlarged schematic cross-sectional view of the periphery of the partition wall shown in FIG. 6. FIG. 14 is a partial perspective view illustrating the configuration of the periphery of the partition wall. FIG. 15 is a block diagram showing a hybrid system according to another embodiment. FIG. 16 is an external perspective view illustrating another battery pack according to the present embodiment. FIG. 17 is a partially exploded perspective view illustrating another battery pack according to the present embodiment. FIG. 18 is a schematic cross-sectional view illustrating another battery pack according to the present embodiment. FIG. 19 is a perspective view illustrating a ceiling surface of a housing cover.

[0013] Preferred embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are preferred specific examples of the present invention, and therefore various technically preferable limitations are applied. However, the scope of the present invention is not limited to these aspects unless otherwise specified in the following description to the effect that the present invention is limited. Furthermore, in each drawing, similar components are designated by the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0014] (Hybrid System) Fig. 1 is a block diagram showing a hybrid system. A battery pack 40 to which a housing according to this embodiment is applied is mounted in a hybrid system 10 shown in Fig. 1. The hybrid system 10 includes an engine 1, a motor generator 2, and the battery pack 40. The hybrid system 10 according to this embodiment further includes a DC / DC converter 70. The engine 1 is an internal combustion engine, such as a diesel engine. The engine 1 is mounted, for example, in a vehicle (such as a passenger car or a small mobile object) or in industrial machinery such as construction machinery or agricultural machinery.

[0015] The engine 1 is, for example, a multi-cylinder diesel engine such as a turbocharged, high-output, three-cylinder or four-cylinder engine. However, the engine 1 is not limited to a diesel engine. The engine 1 has an ECU (Engine Control Unit) 150. The ECU 150 controls the operation of the engine 1 and also controls the motor generator 2 and the DC / DC converter 70 by communicating with them via, for example, a CAN (Controller Area Network).

[0016] The motor generator 2 operates using power supplied from the battery pack 40 to support the engine 1 when power is needed, such as when starting or accelerating the vehicle or the like equipped with the hybrid system 10. The motor generator 2 also uses regenerative braking or the like to convert the kinetic energy of the industrial machinery or the like equipped with the hybrid system 10 into electrical energy to generate electricity.

[0017] The battery pack 40 includes a battery module 50, a positive contactor 75, a negative contactor 76, a current detector 65, a temperature detector 67, a battery management unit (BMU) 85, and a cell management unit (CMU) 87. The battery module 50 is provided as a drive power source for the motor generator 2 and supplies power to the motor generator 2. The battery module 50 includes at least one battery cell 510. In the hybrid system 10 shown in FIG. 1 , the battery module 50 includes the number of battery cells 510 necessary to obtain a voltage of, for example, 48 V. The battery cell 510 may be, for example, a lithium-ion battery (LiB). However, the battery cell 510 in this embodiment is not limited to a lithium-ion battery. The battery module 50 includes a positive (+) terminal 51 and a negative (-) terminal 52.

[0018] The positive contactor 75 is provided in an electrical circuit between the positive terminal 51 of the battery module 50 and the motor generator 2. Specifically, as shown in FIG. 1 , the positive contactor 75 is provided in positive wirings 173, 174 that connect the positive terminal 51 of the battery module 50 and the motor generator 2. In other words, the electrical circuit between the positive terminal 51 of the battery module 50 and the motor generator 2 includes the positive wiring 173 and the positive wiring 174. The positive contactor 75 is electrically connected to the ECU 150 by a signal line 181, and opens and closes the positive wirings 173, 174 based on a control signal transmitted from the ECU 150 via the signal line 181.

[0019] The positive electrode contactor 75 may be electrically connected to the BMU 85. In this case, the positive electrode contactor 75 opens and closes the positive electrode wirings 173, 174 based on a control signal transmitted from the BMU 85. In the description of this embodiment, a case where the positive electrode contactor 75 is electrically connected to the ECU 150 by a signal line 181 will be exemplified.

[0020] The negative contactor 76 is provided in an electrical circuit between the negative terminal 52 of the battery module 50 and the motor generator 2. Specifically, as shown in FIG. 1 , the negative contactor 76 is provided in a negative wiring 175 that connects the negative terminal 52 of the battery module 50 and the motor generator 2. In other words, the electrical circuit between the negative terminal 52 of the battery module 50 and the motor generator 2 includes the negative wiring 175. The negative contactor 76 is electrically connected to the BMU 85 by a signal line 182, and opens and closes the negative wiring 175 based on a control signal transmitted from the BMU 85 through the signal line 182.

[0021] The negative contactor 76 may be electrically connected to the ECU 150. In this case, the negative contactor 76 opens and closes the negative wiring 175 based on a control signal transmitted from the ECU 150. In the description of this embodiment, a case where the negative contactor 76 is electrically connected to the BMU 85 by a signal line 182 will be exemplified.

[0022] The BMU 85 is an example of a "control circuit" in the present invention. The BMU 85 controls the overall voltage of the battery module 50. That is, the BMU 85 is electrically connected to the ECU 150 by a signal line 193, and controls the negative contactor 76 based on a control signal transmitted from the ECU 150 through the signal line 193. The ECU 150 and the BMU 85 communicate with each other, for example, via a CAN, and monitor each other's status.

[0023] The BMU 85 also monitors the state of the battery module 50 and can detect abnormalities in the battery module 50. For example, the BMU 85 detects an overcharge (minor fault) abnormality or an overcharge (major fault) abnormality based on the voltage of the battery cell 510 acquired from the CMU 87. Alternatively, the BMU 85 detects an overdischarge (minor fault) abnormality or an overdischarge (major fault) abnormality based on the voltage of the battery cell 510 acquired from the CMU 87. Alternatively, the BMU 85 detects an overtemperature (minor fault) abnormality based on the temperature of the battery cell 510 acquired from the CMU 87. Alternatively, the BMU 85 detects an overcurrent abnormality based on a current value acquired from a current value detection unit 65 provided in the positive electrode wiring 174.

[0024] The CMU 87 is an example of a "control circuit" of the present invention. The CMU 87 monitors the states of the battery cells 510 included in the battery module 50 and sends the information to the BMU 85. If the battery module 50 includes multiple battery cells 510, the CMU 87 monitors the voltage of each battery cell 510 and sends information about the voltage of each battery cell 510 to the BMU 85 via a signal line 191. The CMU 87 also obtains information about the temperature of the battery cell 510 detected by the temperature detection unit 67 via a signal line 183 and sends the information about the temperature of the battery cell 510 to the BMU 85 via the signal line 191. The CMU 87 may be provided separately from the BMU 85 or may be provided integrally with the BMU 85.

[0025] As described above, the negative electrode wiring 175 electrically connects the negative electrode terminal 52 of the battery module 50 to the motor generator 2 and serves as the ground 100B. For example, the negative electrode wiring 175 is connected to the body of a vehicle or the like in which the hybrid system 10 is mounted and is grounded. The positive electrode wiring 173 electrically connects the positive electrode terminal 51 of the battery module 50 to the motor generator 2 and also electrically connects the motor generator 2 to the DC / DC converter 70. In the hybrid system 10 shown in FIG. 1 , when the battery module 50 is a 48V lithium-ion battery, the potential of the positive electrode wirings 173, 174 relative to the negative electrode wiring 175 is 48V.

[0026] The DC / DC converter 70 is electrically connected to the battery 80 via a positive wiring 171 and a negative wiring 172. An example of the battery 80 is a 12V lead-acid battery. The negative wiring 172 electrically connects the negative terminal 82 of the battery 80 to the DC / DC converter 70 and serves as ground 100B. For example, the negative wiring 172 is connected to the body of a vehicle or the like in which the hybrid system 10 is mounted and is grounded. The positive wiring 171 electrically connects the positive terminal 81 of the battery 80 to the DC / DC converter 70. If the battery 80 is a 12V lead-acid battery as in the hybrid system 10 shown in FIG. 1 , the potential of the positive wiring 171 relative to the negative wiring 172 is 12V.

[0027] As described above, the motor generator 2 generates electricity by converting kinetic energy of a vehicle or the like equipped with the hybrid system 10 into electrical energy using regenerative braking or the like. The motor generator 2 supplies voltage to the battery module 50 to charge the battery module 50, and also supplies voltage to the battery 80 to charge the battery 80. Taking the hybrid system 10 shown in FIG. 1 as an example, the potential of the positive wiring 173 relative to the negative wiring 175 is 48 V. That is, the voltage generated by the motor generator 2 is 48 V. Meanwhile, the potential of the positive wiring 171 relative to the negative wiring 172 is 12 V. Therefore, the DC / DC converter 70 converts the 48 V voltage generated by the motor generator 2 to a 12 V voltage. As a result, the motor generator 2 can supply a 12 V voltage to the battery 80 via the DC / DC converter 70, thereby charging the battery 80.

[0028] Furthermore, DC / DC converter 70 is electrically connected to battery module 50 and battery 80, and can charge and discharge between battery module 50 and battery 80 based on control signals transmitted from ECU 150. For example, DC / DC converter 70 can discharge battery module 50 and charge battery 80 by converting voltage and causing a constant current (e.g., 10 A) to flow from battery module 50 to battery 80. Alternatively, for example, DC / DC converter 70 can discharge battery 80 and charge battery module 50 by converting voltage and causing a constant current (e.g., 10 A) to flow from battery 80 to battery module 50.

[0029] The hybrid system 10 of this embodiment has the function of safely cutting off the electrical circuit that supplies power from the battery module 50 to the motor generator 2 when an abnormality occurs in the battery module 50 or when the entire hybrid system 10 is shut down.

[0030] For example, when the ignition switch is turned on, the ECU 150 transmits a control signal to the positive contactor 75 through a signal line 181 and executes control to close the positive contactor 75, thereby electrically connecting the positive wiring 174. Furthermore, the BMU 85 executes control to close the negative contactor 76 based on a control signal transmitted from the ECU 150 through a signal line 193, thereby electrically connecting the negative wiring 175. This enables the battery module 50 to supply power to the motor generator 2.

[0031] On the other hand, for example, when the ignition switch is turned off, the ECU 150 transmits a control signal to the positive contactor 75 through a signal line 181 and executes control to open the positive contactor 75, thereby electrically disconnecting the positive wiring 174. Furthermore, the BMU 85 executes control to open the negative contactor 76 based on a control signal transmitted from the ECU 150 through a signal line 193, thereby electrically disconnecting the negative wiring 175. This stops the supply of power from the battery module 50 to the motor generator 2.

[0032] Furthermore, when the BMU 85 detects an abnormality in the battery module 50, for example, the ECU 150 transmits a first disconnection signal R1 to the positive contactor 75 via a signal line 181 and executes control to open the positive contactor 75, thereby electrically disconnecting the positive wiring 174. Furthermore, the BMU 85 independently transmits a second disconnection signal R2 to the negative contactor 76 via a signal line 182, without relying on a control signal transmitted from the ECU 150, and executes control to open the negative contactor 76, thereby electrically disconnecting the negative wiring 175.

[0033] Alternatively, as described above, the ECU 150 and the BMU 85 communicate with each other and monitor each other's states. When the ECU 150 detects an abnormality in the BMU 85, the ECU 150 transmits a first shutoff signal R1 to the positive contactor 75 via a signal line 181 and executes control to open the positive contactor 75, thereby electrically shutting off the positive wiring 174. When the BMU 85 detects an abnormality in the ECU 150, the BMU 85 independently transmits a second shutoff signal R2 to the negative contactor 76 via a signal line 182, without relying on a control signal transmitted from the ECU 150, thereby executing control to open the negative contactor 76, thereby electrically shutting off the negative wiring 175.

[0034] According to the hybrid system 10 described above, two contactors (in the present embodiment, the positive electrode contactor 75 and the negative electrode contactor 76) are provided in the electric circuit (in the present embodiment, the positive electrode wirings 173, 174 and the negative electrode wiring 175) that supplies electric power from the battery module 50 to the motor generator 2, and the ECU 150 controls the positive electrode contactor 75, and the BMU 85 controls the negative electrode contactor 76. Therefore, even if an abnormality occurs in the battery module 50 or in either the ECU 150 or the BMU 85, the hybrid system 10 according to the present embodiment can shut off the electric circuit that supplies electric power from the battery module 50 to the motor generator 2. This allows the hybrid system 10 to improve the safety of the battery module 50 that supplies electric power to the motor generator 2.

[0035] (Battery Pack) FIG. 2 is an external perspective view illustrating a battery pack according to this embodiment. FIG. 3 is a partially exploded perspective view illustrating a battery pack according to this embodiment. FIG. 3 shows a state in which the housing cover 420 of the housing 400 of the battery pack 40 is open. The battery pack 40 includes the housing 400 that houses the battery modules 50 and the BMU 85, which is a control circuit. The housing 400 has a housing main body 410 and a housing cover 420. The housing main body 410 and the housing cover 420 are formed by casting using a metal material including, for example, aluminum. A seal (not shown) is provided at the joint between the housing main body 410 and the housing cover 420. By placing the housing cover 420 over the housing main body 410 and fastening it in place with screws, for example, the interior of the housing 400 becomes watertight. External terminals 451 and 452 are provided on the side of the housing main body 410. The external terminals 451, 452 are terminals for outputting power and predetermined signals from the battery pack 40 to the outside, and for inputting signals from the ECU 150 or the like to the battery pack 40. If the external terminals 451, 452 are provided so as to protrude laterally (for example, in the longitudinal direction) from the side surface of the housing main body 410, this contributes to making the battery pack 40 thinner.

[0036] The housing main body 410 has a first storage section 411 that stores the battery module 50 and a second storage section 412 that stores the BMU 85, which is an example of a control circuit. In the housing main body 410, a partition wall 415 is provided between the first storage section 411 and the second storage section 412. That is, one side of the partition wall 415 is the first storage section 411, and the other side is the second storage section 412. By storing the battery module 50 in the first storage section 411 and the BMU 85 in the second storage section 412, the battery module 50 and the BMU 85 are separated from each other by the partition wall 415 within the housing 400. It is preferable that the first storage section 411 be larger than the second storage section 412. Specifically, the distance from the side wall 410b (see FIG. 4) of the housing main body 140 to the partition wall 415 is longer than the distance from the side wall 410c (see FIG. 4) of the housing main body 410 to the partition wall 415. This allows more battery cells 510 to be accommodated in the first accommodating portion 411.

[0037] The partition wall 415 serves to separate the first storage compartment 411 and prevent the internal pressure from increasing in the second storage compartment 412. For example, the battery cell 510 included in the battery module 50 is provided with a valve (safety valve) for releasing internal gas. This valve opens to release the gas when gas is generated inside the battery cell 510 due to an abnormality, such as overcharging or an internal short circuit, and the internal pressure exceeds a predetermined value. When the valve of the battery cell 510 is activated, the gas inside the battery cell 510 is released from the valve to the outside and into the housing 400. Because the housing 400 is configured in a watertight state, the release of gas from the battery cell 510 causes a sudden increase in the internal pressure of the housing 400. A control circuit such as the BMU 85 is provided with a large number of narrow-pitch, thin wiring and connector terminals, and is therefore not highly resistant to deformation or damage. Therefore, if the internal pressure of the housing 400 due to gas release from the battery cell 510 is transmitted to the control circuit, the wiring of the control circuit and the terminals of the connector may be deformed or damaged by the pressure.

[0038] In this embodiment, the housing 400 has a partition wall 415 provided between the first storage section 411 that stores the battery module 50 and the second storage section 412 that stores the control circuit. Therefore, even if the internal pressure of the first storage section 411 suddenly increases due to gas release from the battery cell 510, the partition wall 415 can prevent the pressure from being transmitted to the second storage section 412, making it easier to protect the control circuit stored in the second storage section 412 from pressure.

[0039] The second housing portion 412, which is separated from the first housing portion 411 by the partition wall portion 415, may house the positive contactor 75 and the negative contactor 76 in addition to the control circuit. The second housing portion 412 may also house a CMU 87, which is an example of a control circuit. This prevents the positive contactor 75 and the negative contactor 76 from being affected by an increase in internal pressure in the first housing portion 411. In other words, it is preferable to house circuits and connectors that are susceptible to pressure in the second housing portion 412. In particular, the battery cell 510 may be placed in the first housing portion 411, and all electronic components other than the battery cell 510 may be placed in the second housing portion 412, thereby effectively protecting the electronic components.

[0040] Furthermore, the number of partitions 415 is not limited to one, and the housing 400 may include multiple partitions 415. When multiple partitions 415 are included, the compartment in which the battery module 50 is accommodated is the first accommodating section 411, and the compartment in which the battery module 50 is not accommodated is the second accommodating section 412.

[0041] The partition wall 415 may be provided so as to surround the control circuit within the housing 400, or may be provided over the entire area between two opposing side walls of the housing main body 410. If the partition wall 415 is provided so as to surround the control circuit, the control circuit can be enclosed in a relatively small area and is less susceptible to pressure changes outside the partition wall 415. Furthermore, if the partition wall 415 is provided over the entire area between the two opposing side walls of the housing main body 410, the first accommodating section 411 and the second accommodating section 412 can be easily separated by the partition wall 415, and the partition wall 415 also serves as a beam connecting the two side walls, increasing the strength of the housing 400.

[0042] The partition wall 415 is preferably provided so as to extend from the bottom surface of the housing main body 410 to the ceiling surface 420a (see FIGS. 5 and 6) of the housing cover 420. This effectively prevents pressure from being transmitted from the first housing portion 411 to the second housing portion 412.

[0043] (Housing) FIG. 4 is an external perspective view illustrating a housing main body of the housing according to this embodiment. FIG. 5 is an external perspective view illustrating a housing cover of the housing according to this embodiment. FIG. 5 shows an external perspective view of the housing cover 420 as viewed from the ceiling surface 420a side. As shown in FIG. 4, the housing main body 410 is formed, for example, in a shallow dish shape. The housing main body 410 has a bottom surface 410a and four side walls 410b-e provided around the periphery of the bottom surface 410a. Of the four side walls 410b-e, a main body side partition portion 4151 of the partition portion 415 is provided so as to span between two of the side walls 410d, 410e facing each other.

[0044] 5 , a cover-side partition wall portion 4152 of the partition wall portion 415 is provided on the ceiling surface 420a of the housing cover 420. The cover-side partition wall portion 4152 is provided at a position on the ceiling surface 420a that faces the body-side partition wall portion 4151 when the housing cover 420 is placed on the housing main body 410. As a result, when the housing cover 420 is attached to the housing main body 410, the body-side partition wall portion 4151 and the cover-side partition wall portion 4152 face each other and overlap, thereby forming a single partition wall portion 415.

[0045] The housing cover 420 may include a vent valve 425 that opens when the internal pressure of the first storage portion 411 of the housing 400 reaches a predetermined pressure. The vent valve 425 is preferably provided so as to operate when gas is released from even one of the battery cells 510 included in the battery module 50. This allows an increase in internal pressure that does not occur in the first storage portion 411 to be quickly released, preventing it from affecting the control circuit of the second storage portion 412.

[0046] FIG. 6 is a schematic cross-sectional view illustrating a battery pack using the housing according to this embodiment. FIG. 7 is an enlarged schematic cross-sectional view of the periphery of the partition shown in FIG. 6 . FIG. 8 is a partial perspective view illustrating the configuration of the periphery of the partition. The first housing portion 411 of the housing main body 410 houses the battery module 50, and the second housing portion 412 houses the BMU 85, which is a control circuit. A bus bar 200, which is a conductor for electrically connecting the battery module 50 and the BMU 85, is provided between the battery module 50 and the BMU 85. The bus bar 200 is a metal (e.g., copper) plate formed into a predetermined shape. In this embodiment, since the partition portion 415 is provided between the first housing portion 411 and the second housing portion 412, the bus bar 200 is provided between the first housing portion 411 and the second housing portion 412 so as to cross the partition portion 415. Note that although the present embodiment illustrates the case where the bus bar 200 is used, a conductor other than the bus bar 200 may also be used.

[0047] For example, recesses 201 are provided at positions where the bus bars 200 intersect in the body-side partition wall portion 4151 and at positions where the bus bars 200 intersect in the cover-side partition wall portion 4152, respectively. When the body-side partition wall portion 4151 and the cover-side partition wall portion 4152 are placed face-to-face and overlapped, the recesses 201 of both portions become holes in the partition wall portion 415. The holes correspond to the cross-sectional shape of the bus bars 200. When the bus bars 200 are passed through these holes, the bus bars 200 intersect the partition wall portion 415. When the housing cover 420 is attached to the housing body 410, the bus bars 200 close these holes. As a result, even if holes are formed in the partition wall portion 415 by the recesses 201, pressure leakage paths between the first accommodating portion 411 and the second accommodating portion 412 are effectively blocked. The surface of bus bar 200 is covered with an insulating member (not shown), so that there is no electrical connection between partition wall 415 and bus bar 200. A member with high sealing properties (such as a liquid gasket) may be interposed between bus bar 200 and partition wall 415.

[0048] Furthermore, if it is necessary to pass wiring other than the bus bar 200 between the first housing portion 411 and the second housing portion 412 (for example, wiring for transmitting a temperature sensor or voltage detection signal provided in the battery module 50 to the BMU 85), a recess 202 (see FIG. 8 ) may be provided in the partition wall portion 415. When the body-side partition wall portion 4151 and the cover-side partition wall portion 4152 are placed face-to-face and overlapped, the recess 202 becomes a through-hole provided in the partition wall portion 415. The wiring is passed between the first housing portion 411 and the second housing portion 412 through this through-hole. Note that it is preferable to provide a sealant between the through-hole and the wiring. This suppresses pressure leakage through the through-hole in the partition wall portion 415.

[0049] According to this embodiment, it is possible to provide a housing 400 and a battery pack 40 that can suppress the impact on components inside the housing 400 even if an increase in internal pressure occurs in the housing 400.

[0050] Another embodiment Fig. 9 is a block diagram showing a hybrid system according to another embodiment. As shown in Fig. 9, the hybrid system 10 may be configured to include one contactor 77. The contactor 77 is provided between the battery module 50 and the BMU 85. In the example shown in Fig. 9, the contactor 77 is provided between the negative terminal 52 of the battery module 50 and the BMU 85, but the contactor 77 may be provided between the positive terminal 51 of the battery module 50 and the BMU 85.

[0051] If the BMU 85 detects an abnormality in the battery module 50, for example, the BMU 85 transmits a second shutoff signal R2 to the contactor 77 and executes control to open the contactor 77. This electrically shuts off the negative wiring 175, thereby ensuring the safety of the battery module 50.

[0052] (Another Battery Pack) Next, another battery pack will be described. Note that, when components of the other battery pack 40 are similar to those of the battery pack 40 described above with reference to FIGS. 2 to 8 , redundant description will be omitted as appropriate, and the following description will focus on the differences. FIG. 10 is an external perspective view illustrating another battery pack according to this embodiment. FIG. 11 is a partially exploded perspective view illustrating another battery pack according to this embodiment. FIG. 11 shows a state in which the housing cover 420 and the thermal conduction member 600 of the housing 400 of the battery pack 40 are open. FIG. 12 is a schematic cross-sectional view illustrating another battery pack according to this embodiment. The battery pack 40 includes a battery module 50, a control circuit including a BMU 85 and a CMU 87, and a housing 400 that accommodates the battery module 50 and the control circuit. The housing main body 410 and the housing cover 420 are formed by casting using a metal material including, for example, aluminum. A seal (not shown) is provided at the joint between the housing body 410 and the housing cover 420, and by placing the housing cover 420 over the housing body 410 and fastening it in place with screws, for example, the inside of the housing 400 becomes watertight.

[0053] The battery module 50 housed in the housing 400 includes, for example, a plurality of battery cells 510. One battery module 50 may be housed in one housing 400, or a plurality of battery modules 50 may be housed in one housing 400.

[0054] The battery cells 510 are provided in a generally rectangular parallelepiped shape having flat surfaces (top surface 510a and bottom surface 510b) facing each other and four side surfaces 510c each having a smaller area than the top surface 510a and bottom surface 510b. The battery cells 510 are arranged side by side along the bottom surface 400a of the housing 400 so that the bottom surface 510b faces the bottom surface 400a.

[0055] The battery module 50 may have a plurality of battery cells 510. In this case, the plurality of battery cells 510 are preferably arranged side by side along the bottom surface 400a of the housing 400. The battery cells 510 may be arranged in a single row or in a plurality of rows in the housing 400. In the case of a plurality of rows, the battery cells 510 are preferably arranged such that the top surface portions 510a and bottom surface portions 510b of two battery cells 510 in the stacking direction face each other.

[0056] An insulating heat-conducting member 600 is provided between the battery module 50 accommodated in the housing 400 and the housing 400. The heat-conducting member 600 is made of, for example, a silicone sheet having insulating and thermally conductive properties. The heat-conducting member 600 is disposed between the upper surface 510a of the battery cell 510 and the ceiling surface 420a of the housing cover 420 (housing 400) that faces the bottom surface 400a of the housing 400. The heat-conducting member 600 is preferably in contact with both the upper surface 510a of the battery cell 510 and the ceiling surface 420a of the housing cover 420. Note that some other member may be interposed between the heat-conducting member 600 and the upper surface 510a and between the heat-conducting member 600 and the ceiling surface 420a.

[0057] The battery cell 510 is arranged so that the bottom surface portion 510b faces the bottom surface 400a of the housing 400, and thus the top surface portion 510a of the battery cell 510 faces the ceiling surface 420a of the housing cover 420. In the battery cell 510, the area of ​​the top surface portion 510a is larger than the area of ​​the side surface portion 510c. Therefore, when the top surface portion 510a and the heat conduction member 600 come into contact (including when the contact is via a member), heat generated in the battery cell 510 can be effectively conducted to the heat conduction member 600. Furthermore, when the heat conduction member 600 comes into contact (including when the contact is via a member) with the ceiling surface 420a of the housing cover 420, heat conducted from the battery cell 510 to the heat conduction member 600 can be effectively conducted to the housing cover 420, and can be easily dissipated from the housing 400 to the outside.

[0058] The battery pack 40 may include a plurality of battery modules 50. In this case, the plurality of battery modules 50 are preferably arranged side by side along the bottom surface 400a of the housing 400. This prevents the upper surface portions 510a of the battery cells 510 in the plurality of battery modules 50 from overlapping, which is advantageous in terms of heat dissipation.

[0059] In a configuration in which a plurality of battery modules 50 are arranged side by side, the heat conduction member 600 may have a portion that is disposed between adjacent battery modules 50 among the plurality of battery modules 50. By disposing a portion of the heat conduction member 600 between adjacent battery modules 50, heat can be more easily conducted to the heat conduction member 600 not only from the upper surface portion 510 a of the battery cell 510 but also from a portion of the side surface portion 510 c.

[0060] FIG. 13 is a perspective view illustrating the ceiling surface of the housing cover. The housing cover 420 is formed, for example, by casting using aluminum. The ceiling surface 420a of the housing cover 420 has a first region A1 facing the battery module 50 (see FIG. 11) and a second region A2 outside the first region A1. In the housing cover 420, the surface roughness of the first region A1 is preferably lower than that of the second region A2. For example, when the housing cover 420 is formed by casting, the surface of the casting mold is transferred to both the first region A1 and the second region A2, resulting in a relatively rough surface roughness. Therefore, the first region A1 is subjected to a cutting process or the like to reduce the surface roughness of the first region A1 compared to the second region A2. This improves the adhesion between the first region A1 and the thermal conduction member 600 on the ceiling surface 420a of the housing cover 420, allowing for more effective heat transfer from the thermal conduction member 600 to the housing cover 420.

[0061] According to this embodiment, it is possible to provide a battery pack 40 that can efficiently release heat from the battery cells 510 to the outside.

[0062] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. For example, the configurations of the above embodiments can be partially omitted or arbitrarily combined in a different manner from the above.

[0063] REFERENCE SIGNS LIST 1...engine, 2...motor generator, 10...hybrid system, 40...battery pack, 50...battery module, 51...positive terminal, 52...negative terminal, 65...current value detection unit, 67...temperature detection unit, 70...DC / DC converter, 75...positive contactor, 76...negative contactor, 77...contactor, 80...battery, 81...positive terminal, 82...negative terminal, 85...BMU, 87...CMU, 100B...ground, 150...ECU, 171...positive wiring, 172...negative wiring, 173...positive wiring, 174...positive wiring, 175...negative wiring, 181...signal line, 182...signal line, 183...signal line, 191...signal line, 193...signal line, 200...bus Bar, 201...recess, 202...recess, 400...housing, 400a...bottom, 410...housing main body, 410a...bottom, 410b...side wall, 410c...side wall, 410d...side wall, 410e...side wall, 411...first storage section, 412...second storage section, 415...partition wall, 420...housing cover, 420a...ceiling surface, 425...vent valve, 451...external terminal, 452...external terminal, 510...battery cell, 510a...top surface (flat portion), 510b...bottom surface (flat portion), 510c...side portion, 600...thermal conduction member, 4151...main body side partition wall portion, 4152...cover side partition wall portion, A1...first region, A2...second region, R1...first shut-off signal, R2...second shut-off signal

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