Pair of circuit units

Abstract

To provide a pair of circuit units, to be stored in an enclosure of a battery pack, with a low number of parts and low assembly man-hours.SOLUTION: A pair of circuit units 10 comprises circuit units 10a, 10b. Each of the circuit units 10a, 10b includes a circuit configuration part 34 and a case 36. The circuit unit 10a includes a first fan motor 38, a second fan motor 40, and a fan driving part 42. The case 36a of the circuit unit 10a has a first suction hole 44, a first exhaust hole 46, a second suction hole 48, and a second exhaust hole 50. A heating component 14 of the circuit unit 10a is disposed on a downstream side of the first fan motor 38 and on an upstream side of the first exhaust hole 46 in a blowing direction α. The case 36b of the circuit unit 10b has an other-side suction hole 116 and an other-side exhaust hole 118. The heating component 14 of the circuit unit 10b is disposed between the other-side suction hole 116 and the other-side exhaust hole 118 in a blowing direction β.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a pair of circuit units. [Background technology]

[0002] Patent Document 1 discloses a relay unit as a circuit unit that is mounted on a vehicle and disposed in a power supply path from a power source to a load. The relay unit in Patent Document 1 includes a fan motor, and employs a structure that promotes heat dissipation from the relay by cooling a heat dissipation component fixed to the terminal of the relay, which is a heat generating component, with air blown by the fan motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-206601 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in recent years, a circuit unit equipped with a heat generating component such as a relay as exemplified in Patent Document 1 may be housed inside a battery pack, which is one of the power sources mounted on a vehicle. In such a case, at least two circuit units, one on the positive side and one on the negative side, are housed inside the housing of the battery pack. Since the fan motor mounted on each circuit unit is driven, for example, during quick charging or when a current of a certain level or more flows, it is necessary to route and assemble a wire harness including electric wires for the fan motor driving power source and control signals from a BMS (Battery Management System) or the like mounted in the same battery pack to each circuit unit, which leads to an increase in the number of parts and assembly steps.

[0005] In view of this, a pair of circuit units housed within a battery pack housing is disclosed, which allows for a reduction in the number of parts and assembly steps. [Means for solving the problem]

[0006] The pair of circuit units of the present disclosure are a pair of circuit units housed in a housing of a battery pack, each of the circuit units including a circuit configuration section including heat-generating components, and a case housing the circuit configuration section, one of the pair of circuit units includes a first fan motor and a second fan motor, and a fan drive section provided in the circuit configuration section and driving the first fan motor and the second fan motor, and the case of the one circuit unit includes a first intake hole provided upstream of the first fan motor in the air blowing direction, a first exhaust hole provided downstream of the first fan motor in the air blowing direction, a second intake hole provided upstream of the second fan motor in the air blowing direction, and a second exhaust hole provided in front of the second fan motor. and a second exhaust hole provided downstream in the air blowing direction, the heat-generating component of the one circuit unit is arranged downstream of the first fan motor in the air blowing direction of the first fan motor and upstream of the first exhaust hole, the case of the other circuit unit is provided downstream in the air blowing direction of the second fan motor and has a other-side intake hole through which the air blown by the second fan motor passing through the second exhaust hole passes, and a other-side exhaust hole provided downstream in the air blowing direction of the second fan motor than the other-side intake hole, and the heat-generating component of the other circuit unit is arranged between the other-side intake hole and the other-side exhaust hole in the air blowing direction of the second fan motor. Effect of the Invention

[0007] According to the pair of circuit units of the present disclosure, the number of parts and the number of assembly steps can be reduced and the circuit units can be accommodated within the housing of the battery pack. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a battery pack including a pair of circuit units according to the first embodiment with a cover constituting a housing removed. [Diagram 2] FIG. 2 is an enlarged plan view showing a main part of the battery pack shown in FIG. [Diagram 3] FIG. 3 is a perspective view showing one of the pair of circuit units according to the first embodiment with an upper case that constitutes a case removed. [Figure 4] FIG. 4 is a plan view of the circuit unit shown in FIG. [Diagram 5] FIG. 5 is an enlarged longitudinal sectional view showing the VV cross section in FIG. [Figure 6] FIG. 6 is an exploded perspective view of the circuit unit shown in FIG. [Figure 7] FIG. 7 is an exploded perspective view showing a circuit configuration portion that constitutes the circuit unit shown in FIG. 3 in an exploded state. [Figure 8] FIG. 8 is a perspective view showing the other of the pair of circuit units according to the first embodiment with an upper case that constitutes a case removed. [Figure 9] FIG. 9 is a plan view showing a pair of circuit units according to another embodiment of the present disclosure housed in a battery pack, and corresponds to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Description of the embodiments of the present disclosure> First, embodiments of the present disclosure will be listed and described. The pair of circuit units according to the present disclosure includes: (1) A pair of circuit units housed in a housing of a battery pack, each of the circuit units including a circuit configuration section including a heat-generating component and a case housing the circuit configuration section, one of the pair of circuit units including a first fan motor and a second fan motor, and a fan drive section provided in the circuit configuration section and driving the first fan motor and the second fan motor, the case of the one circuit unit including a first intake hole provided upstream of the first fan motor in the air blowing direction, a first exhaust hole provided downstream of the first fan motor in the air blowing direction, a second intake hole provided upstream of the second fan motor in the air blowing direction, and a second exhaust hole provided downstream of the second fan motor in the air blowing direction. and a second exhaust hole provided downstream of the first fan motor in the air blowing direction of the first fan motor, the heat-generating component of the one circuit unit is arranged downstream of the first fan motor and upstream of the first exhaust hole, the case of the other circuit unit is provided downstream of the air blowing direction of the second fan motor and has a other-side intake hole through which the air blown by the second fan motor passing through the second exhaust hole passes, and a other-side exhaust hole provided downstream of the other-side intake hole in the air blowing direction of the second fan motor, and the heat-generating component of the other circuit unit is arranged between the other-side intake hole and the other-side exhaust hole in the air blowing direction of the second fan motor.

[0010] According to this aspect, in a pair of circuit units (e.g., for positive and negative poles) housed in the housing of a battery pack, when each circuit unit includes a heat-generating component and a fan motor for cooling the heat-generating component is required, the first fan motor, the second fan motor, and the fan drive unit are mounted in one of the pair of circuit units, so that the two fan motors can be driven by one fan drive unit. This eliminates the need to route wire harnesses for the drive power sources of the first fan motor and the second fan motor from the outside, and even if a signal line for sending a control signal for controlling the ON / OFF of the drive unit needs to be routed from the outside, it is sufficient to route only one of the circuit units. Therefore, the number of wire harnesses connected to the pair of circuit units mounting the fan motors and the assembly man-hours can be reduced.

[0011] In particular, by installing a first fan motor for cooling one circuit unit and a second fan motor for cooling the other circuit unit in one circuit unit, it is sufficient to route the wires connecting the fan drive unit and the first fan motor / second fan motor inside the case and there is no need to route them outside the case, so that the wire harness connecting the pair of circuit units can be eliminated or reduced, thereby reducing the wiring space for the pair of circuit units and further reducing the assembly process.

[0012] In addition, the heat-generating components of one of the circuit units can be cooled quickly by providing a first intake hole and a first exhaust hole on the upstream and downstream sides of the air blowing direction of the first fan motor in the case of the one of the circuit units, and arranging the heat-generating components between the first fan motor and the first exhaust hole, so that the heat-generating components of the one of the circuit units can be quickly cooled by the air blown by the first fan motor.

[0013] In addition, in order to cool the heat-generating components of the other circuit unit, a second-side intake hole, through which the air blown by the second fan motor passes after passing through the second exhaust hole, is located downstream in the air blowing direction of the second fan motor in the case of the other circuit unit, and a second-side exhaust hole is located further downstream than the second-side intake hole, and electrical components (heat-generating components) are located between them, so that the heat-generating components of the other circuit unit can be quickly cooled by the air blown by the second fan motor.

[0014] (2) In the above (1), it is preferable that the circuit unit includes a heat sink thermally connected to each of the heat generating components, and each of the heat sinks is disposed downstream of the first fan motor or the second fan motor in the air blowing direction. Heat generated by the heat generating components is efficiently transferred to the heat sink, and heat dissipation from the heat sink is further promoted by utilizing the air blown by the fan motor. This advantageously improves the heat dissipation of the heat generating components in the circuit unit.

[0015] (3) In the above (1) or (2), it is preferable that the second fan motor is disposed so that the intake side of the second fan motor faces the first fan motor at a distance from the first fan motor upstream in the air blowing direction of the first fan motor, an intake area is formed between the opposing surfaces of the first fan motor and the second fan motor, and a plurality of through holes are provided in an area covering the intake area in the case of the one of the circuit units, and the first intake hole and the second intake hole are formed by sharing the plurality of through holes. When the first fan motor and the second fan motor are mounted in one of the circuit units, the intake area of ​​the two fan motors can be shared, and the first intake hole and the second intake hole can be provided by sharing the plurality of through holes provided through the case covering the intake area. This makes it possible to mount two fan motors in one of the circuit units with space efficiency while suppressing the increase in size of one of the circuit units, which is a concern when mounting two fan motors.

[0016] (4) In any one of (1) to (3) above, it is preferable that the heat-generating component of the one circuit unit is disposed downstream of the first fan motor in the air blowing direction and not upstream of the first fan motor. By disposing the heat-generating component downstream of the first fan motor and not upstream of it, it is possible to prevent a malfunction such as the temperature of the intake side of the first fan motor rising due to the heat-generating component and exceeding the upper operating temperature limit of the first fan motor.

[0017] <Details of the embodiment of the present disclosure> Specific examples of a pair of circuit units according to the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0018] <Embodiment 1> A pair of circuit units 10 according to a first embodiment of the present disclosure will be described below with reference to FIGS. 1 to 8. The pair of circuit units 10 are housed inside a battery pack 12 in an electric vehicle or a hybrid vehicle, and can suppress the battery module 16 in the battery pack 12 from being adversely affected by heat generated by air heated by heat generating components 14 provided inside each of the circuit units 10a and 10b. In the first embodiment, one of the pair of circuit units 10 is configured by a negative-electrode circuit unit 10a, and the other of the pair of circuit units 10 is configured by a positive-electrode circuit unit 10b. The battery pack 12 can be arranged in any direction in the vehicle, but in the following description, the upper side refers to the front side in the direction perpendicular to the paper surface in FIG. 2 (upper side in FIG. 5), the lower side refers to the rear side in the direction perpendicular to the paper surface in FIG. 2 (lower side in FIG. 5), the left side refers to the left side in FIG. 2, the right side refers to the right side in FIG. 2, the front side refers to the lower side in FIG. 2, and the rear side refers to the upper side in FIG. 2. In addition, in the case of multiple identical components, reference numerals may be given to only some of the components and the reference numerals may be omitted for the other components.

[0019] <Battery pack 12> The battery pack 12 is configured by housing a battery module 16 including a plurality of battery cells (single cells) 18 in a housing 20. In the first embodiment, each battery cell 18 has a substantially rectangular parallelepiped shape and is arranged in a direction in which the left-right dimension is larger than the front-rear dimension. The battery cells 18 are arranged in parallel at a predetermined distance in the front-rear and left-right directions, and these battery cells 18 are electrically connected, for example, by a bus bar module (not shown) extending in the front-rear direction. The battery cells 18 may be electrically connected in series or in parallel by the bus bar module. The battery modules 16 are configured by connecting the battery cells 18 by the bus bar module.

[0020] At least one of the battery cells 18 is provided on the upper surface with a BMS (Battery Management System). A BMS board 22 is placed in a state housed in a case. This BMS board 22 is electrically connected via wires (not shown) to a bus bar module that electrically connects each battery cell 18. A known BMS board 22 may be used as the BMS board 22, and has a function of, for example, eliminating voltage differences between the battery cells 18 connected in series within the battery module 16 to adjust the balance, and measuring the voltage, current, temperature, etc. of each battery cell 18 to monitor for the presence or absence of abnormalities.

[0021] The housing 20 has a hollow rectangular box shape as a whole, and is composed of a housing body 24 that opens upward, and a lid 28 that covers an upper opening 26 of the housing body 24. The housing 20 is made of metal, for example, aluminum or aluminum alloy. The method of fixing the housing body 24 and the lid 28 is not limited, but they are fixed by bolts, screws, or the like. In the first embodiment, when the battery module 16 is housed in the housing body 24, a gap is provided between the battery module 16 and the front wall of the housing body 24, and the pair of circuit units 10 described above are mounted between the battery module 16 and the front wall of the housing body 24.

[0022] In the first embodiment, the battery pack 12 is provided with exhaust direction regulating parts 30, 30 that regulate the direction of exhaust air that has passed through the first exhaust hole 46 and the other-side exhaust hole 118, which will be described later, in each of the circuit units 10a, 10b. In particular, in the first embodiment, each of the exhaust direction regulating parts 30 is formed integrally with the housing body 24, and each of the exhaust direction regulating parts 30 is formed to protrude inward in the left-right direction from the wall parts on both the left and right sides of the housing body 24. Each of the exhaust direction regulating parts 30 has a triangular shape in a plan view (viewed in the up-down direction), and the front end surface is configured as an inclined surface 32 that is inclined with respect to the left-right direction and the front-rear direction.

[0023] <Each circuit unit (negative electrode circuit unit 10a and positive electrode circuit unit 10b)> As described above, the pair of circuit units 10 is composed of a negative pole circuit unit 10a and a positive pole circuit unit 10b. The negative pole circuit unit 10a is electrically connected to the negative electrode of the battery module 16 (bus bar module connecting each battery cell 18) via an electric wire or the like (not shown). The positive pole circuit unit 10b is electrically connected to the positive electrode of the battery module 16 (bus bar module connecting each battery cell 18) via an electric wire or the like (not shown). The negative pole circuit unit 10a is provided on the right side of the battery pack 12, and the positive pole circuit unit 10b is provided on the left side of the battery pack 12.

[0024] The negative circuit unit 10a and the positive circuit unit 10b are each rectangular parallelepiped and are arranged in a direction extending in the left-right direction inside the housing body 24. As described later, a first exhaust hole 46 is provided at the right end of the negative circuit unit 10a, and a second exhaust hole 118 is provided at the left end of the positive circuit unit 10b. Therefore, the exhaust direction regulating portion 30a for the negative electrode is provided on the right wall of the housing body 24, and the exhaust direction regulating portion 30b for the positive electrode is provided on the left wall of the housing body 24. The negative circuit unit 10a has a longer length dimension in the left-right direction than the positive circuit unit 10b.

[0025] As a structure common to each of the circuit units 10a, 10b, each of the circuit units 10a, 10b includes a circuit configuration section 34 (a circuit configuration section 34a for a negative pole and a circuit configuration section 34b for a positive pole) that includes a heat-generating component 14, and a case 36 (a case 36a for a negative pole and a case 36b for a positive pole) that houses each of the circuit configuration sections 34a, 34b.

[0026] <One of the circuit units (negative electrode circuit unit 10a)> 3 to 7, the negative pole circuit unit 10a includes a first fan motor 38, a second fan motor 40, and a fan drive unit 42 that drives the first fan motor 38 and the second fan motor 40. This fan drive unit 42 is provided in the negative pole circuit configuration unit 34a described above.

[0027] The negative pole case 36a has a first intake hole 44 provided upstream (left) in the airflow direction α (shown by a two-dot chain line in FIG. 2) of the first fan motor 38, and a first exhaust hole 46 provided downstream (right) in the airflow direction α of the first fan motor 38. The negative pole case 36a also has a second intake hole 48 provided upstream (right) in the airflow direction β of the second fan motor 40, and a second exhaust hole 50 provided downstream (left) in the airflow direction β of the second fan motor 40.

[0028] The heat-generating component 14 in the negative pole circuit unit 10a is provided downstream (to the right) of the first fan motor 38 and upstream (to the left) of the first exhaust hole 46 in the air blowing direction α of the first fan motor 38. That is, in the negative pole circuit unit 10a, the heat-generating component 14 is provided between the first fan motor 38 and the first exhaust hole 46 in the left-right direction.

[0029] <Heat generating component 14 (relay 52 and fuse 54)> The heat generating component 14 in the negative pole circuit unit 10a includes a relay 52 as a first heat generating component and a fuse 54 as a second heat generating component. In the first embodiment, two relays 52, 52 are provided at a distance from each other in the left-right direction in the right part of the negative pole circuit unit 10a. Each relay 52 has a case body 56 having a substantially hollow rectangular box shape, and a pair of terminals 58, 58 are exposed from the case body 56 at the front side of each relay 52 (the front side of the right relay 52, and the rear side of the left relay 52) at a distance from each other in the left-right direction. In each case body 56, an insulating partition plate 60 is provided between the terminals 58, 58 to separate the terminals 58.

[0030] A heat sink 62 is thermally connected to each terminal portion 58 of each relay 52. ​​In the first embodiment, two heat sinks 62, 62 are provided with a gap between them in the left-right direction. As shown in FIG. 4, each heat sink 62 is substantially rectangular in plan view, and each heat sink 62 has a plate-shaped portion 64 extending in the horizontal direction (direction perpendicular to the up-down direction) at its lower end. Each heat sink 62 has a plurality of heat sinks 66 protruding upward from the plate-shaped portion 64, and the heat sinks 66 are arranged in parallel and spaced apart from each other in the front-rear direction, and extend in the left-right direction. As a result, a gap 68 extending in the left-right direction is provided between the heat sinks 66 in the front-rear direction.

[0031] 6 and 7, the terminal portion 58 of each relay 52 is connected with bolts (not shown) to the energizing bus bars 72d-72g which constitute the negative-pole circuit configuration portion 34a. The energizing bus bars 72d-72g extend upward from the fixed portions with the terminal portions 58, and then bend inward in the front-rear direction to cover the upper portions of the relays 52. The heat sinks 62 are fixed to the portions 72a of the energizing bus bars 72d-72g which cover the upper portions of the relays 52 via the insulating heat-conductive sheets 70.

[0032] Each insulating heat conductive sheet 70 is a sheet-like member having electrical insulation and good thermal conductivity, and a known one may be used. Each insulating heat conductive sheet 70 may be, for example, grease-like or gel-like, and may be applied to a predetermined position and then cured by heat or light (ultraviolet rays). The portion 72a of each of the current-carrying bus bars 72d to 72g covering the upper part of each of the relays 52 and the heat sink 62 may be fixed with an adhesive or bolts through each of the insulating heat conductive sheets 70, or both an adhesive and bolts may be used. As a result, each of the relays 52 and each of the heat sinks 62 are fixed through each of the current-carrying bus bars 72d to 72g and each of the insulating heat conductive sheets 70, and each of the heat sinks 62 is thermally connected to each of the terminal parts 58.

[0033] A fuse 54 is provided as a second heat generating component on the rear side of the left-right middle portion of the negative circuit unit 10a. The fuse 54 in the negative circuit unit 10a may be, for example, a pyro fuse. The amount of heat generated by this fuse 54 during energization is smaller than that of each of the relays 52, that is, the amount of heat generated by the second heat generating component (fuse 54) is smaller than that of the first heat generating component (relays 52).

[0034] <Circuit configuration unit 34 (negative electrode circuit configuration unit 34a)> The relays 52 and the fuses 54 are electrically connected by a plurality of current-carrying bus bars 72. That is, the current-carrying bus bars 72 are overlapped with a pair of terminals 74, 74 of the fuse 54 and with the terminals 58 of the relays 52, and are fixed by bolts 76 (one is shown in FIG. 5). Specifically, the current-carrying bus bar 72b is fixed to the left terminal 74 of the fuse 54, and the right terminal 74 of the fuse 54 and the left terminal 58 of the left relay 52 are connected by current-carrying bus bars 72c, 72d. The right terminal 58 of the left relay 52 and the left terminal 58 of the right relay 52 are connected by the current-carrying bus bar 72e, and the current-carrying bus bar 72f is fixed to the right terminal 58 of the right relay 52. Further, an energizing bus bar 72g, which is separate from energizing bus bar 72e, is overlapped and fixed to the right terminal portion 58 of the left relay 52 and extends to the right.

[0035] As a result, an external connection portion 78 is formed by the end of the current-carrying busbar 72b at the left end of the negative-electrode circuit unit 10a, and an external connection portion 80 is formed by the ends of the current-carrying busbars 72f, 72g at the right end of the negative-electrode circuit unit 10a. Terminal portions provided at the ends of external electric wires (not shown) are overlapped with these external connection portions 78, 80 and fixed with bolts or the like, so that each of the current-carrying busbars 72b to 72g and each of the relays 52 and fuses 54 are electrically connected to the external electric wires. Although not limited thereto, for example, the external connection portion 78 is connected to the battery module 16 (particularly the busbar module) to serve as a connection portion for inputting electric power to the negative-electrode circuit unit 10a, and each of the external connection portions 80 is connected to an external electric device to serve as a connection portion for outputting electric power to the external electric device.

[0036] A fan drive unit 42 is provided in the left-right intermediate portion of the negative pole circuit unit 10a, specifically between the fuse 54 and the left relay 52 in the left-right direction. The fan drive unit 42 is configured by, for example, housing a board or the like on which a microcomputer (not shown) or the like is mounted in a case, and receives a fan drive signal or the like to transmit a drive signal to the first and second fan motors 38, 40, thereby driving the first and second fan motors 38, 40. The fan drive unit 42 and the first and second fan motors 38, 40 are electrically connected by electric wires 82, 82, respectively.

[0037] In the first embodiment, the fan drive unit 42 also has a monitoring function for monitoring the internal state of the negative pole circuit unit 10a. The internal state of the negative pole circuit unit 10a monitored by the fan drive unit 42 is, for example, the internal temperature of the negative pole circuit unit 10a or the current flowing through the negative pole circuit unit 10a.

[0038] That is, the fan drive unit 42 may include a temperature sensor (not shown), and the fan drive unit 42 monitors the temperature in the negative pole circuit unit 10a or the battery pack 12, and when the temperature exceeds a predetermined temperature, transmits a drive signal to the first fan motor 38 or the second fan motor 40 to drive the first and second fan motors 38, 40. Alternatively, when the fan drive unit 42 monitors the current flowing through the negative pole circuit unit 10a, for example, the fan drive unit 42 may be provided with a current sensor (not shown), and when a current larger than a predetermined value is detected, the fan drive unit 42 may transmit a drive signal to the first fan motor 38 or the second fan motor 40. Therefore, the fan drive unit 42 may be electrically connected to, for example, the current busbars 72 (current busbars 72b to 72g) in the negative pole circuit unit 10a.

[0039] Alternatively, the fan drive unit 42 may be electrically connected to the aforementioned BMS board 22 provided in the battery pack 12, and when the BMS board 22 detects that the temperature or current (or voltage) in the battery pack 12 exceeds a predetermined value, the BMS board 22 may send a signal to the fan drive unit 42 to drive the first fan motor 38 and the second fan motor 40.

[0040] Therefore, in embodiment 1, the negative pole circuit component 34a in the negative pole circuit unit 10a is configured to include each relay 52 which is a first heat-generating component, a fuse 54 which is a second heat-generating component, a fan drive unit 42 and each of the current-carrying bus bars 72b to 72g.

[0041] In particular, in the first embodiment, a plurality of heat dissipation busbars 84 are fixed at the fixing points between the terminals 74 of the fuse 54 and the current-carrying busbars 72b, 72c, and at the fixing points between the terminals 58 of the relays 52 and the current-carrying busbars 72d to 72g. Each heat dissipation busbar 84 is substantially L-shaped and has a heat dissipation portion 86 that spreads in the horizontal direction and a portion that protrudes upward from each heat dissipation portion 86. The upward protruding portion of each heat dissipation busbar 84 is fastened together with each current-carrying busbar 72b to 72g to each terminal 74 of the fuse 54 and each terminal 58 of each relay 52 by bolts (for example, bolts 76) and fixed. When assembling the negative-electrode circuit unit 10a, the heat dissipation portion 86 of each heat dissipation busbar 84 is overlapped with a negative-electrode lower case 92 (described later) constituting the case 36 (negative-electrode case 36a) via an insulating heat-conductive sheet 88. The insulating heat conductive sheet 88 may be the same as the insulating heat conductive sheet 70 described above.

[0042] <Case 36 (negative electrode case 36a)> The negative electrode case 36a is generally in the shape of a hollow rectangular parallelepiped, and is configured to include a negative electrode upper case 90 and a negative electrode lower case 92 which can be assembled and disassembled relative to each other in the vertical direction. The negative electrode upper case 90 and the negative electrode lower case 92 are formed of, for example, synthetic resin.

[0043] <Negative pole upper case 90> The negative electrode upper case 90 is generally box-shaped and opens downward, and includes an upper bottom wall 94 and an upper peripheral wall 96 that protrudes downward from the outer periphery of the upper bottom wall 94. That is, the upper peripheral wall 96 includes an upper front wall 96a that constitutes the front wall, an upper rear wall 96b that constitutes the rear wall, an upper left wall 96c that constitutes the left wall, and an upper right wall 96d that constitutes the right wall. The negative electrode upper case 90 is formed with a size such that the left-right dimension is larger than the front-rear dimension.

[0044] As described above, the negative pole case 36a is provided with the first intake hole 44, the first exhaust hole 46, the second intake hole 48, and the second exhaust hole 50. As described later, the negative pole case 36a is provided with the second fan motor 40 at the left end portion, and the first fan motor 38 is provided at a predetermined distance to the right of the second fan motor 40. Therefore, the negative pole case 36a is provided with the first intake hole 44 and the second intake hole 48 between the first fan motor 38 and the second fan motor 40 in the left-right direction, which is upstream (left) of the airflow direction α of the first fan motor 38 and upstream (right) of the airflow direction β of the second fan motor 40. The negative pole case 36a is provided with the first exhaust hole 46 at the right end portion of the negative pole case 36a, which is downstream (right) of the airflow direction α of the first fan motor 38. Furthermore, in the negative pole case 36a, a second exhaust hole 50 is provided at the left end portion of the negative pole case 36a, which is on the downstream side (left side) in the air blowing direction β of the second fan motor 40.

[0045] In the first embodiment, the first air intake hole 44, the first exhaust hole 46, the second air intake hole 48, and the second exhaust hole 50 are all provided in the negative electrode upper case 90. In particular, in the first embodiment, the first air intake hole 44 and the second air intake hole 48 are formed in the same portion of the negative electrode upper case 90, and the first air intake hole 44 and the second air intake hole 48 are configured by the same hole portion provided in the negative electrode upper case 90.

[0046] Each of the first air intake hole 44, the first exhaust hole 46, the second air intake hole 48 and the second exhaust hole 50 is formed by a plurality of through holes 98 that penetrate in the thickness direction of each wall portion of the negative electrode upper case 90. The through holes 98 that penetrate each wall portion of the negative electrode upper case 90 are aligned in the front-rear direction and / or the left-right direction.

[0047] The first intake hole 44 and the second intake hole 48 are formed by a plurality of through holes 98 penetrating the upper bottom wall 94, the upper front wall 96a, and the upper rear wall 96b in the thickness direction in the left-right direction between the first fan motor 38 and the second fan motor 40 (intake area 106 described later). In other words, the first intake hole 44 and the second intake hole 48 are formed by sharing the plurality of through holes 98 in the region covering the intake area 106 in the negative pole upper case 90.

[0048] The first exhaust hole 46 is formed by a plurality of through holes 98 penetrating each wall in the thickness direction at the right end of the upper bottom wall 94, the upper front wall 96a, and the upper rear wall 96b, and at the upper right wall 96d. The second exhaust hole 50 is formed by a plurality of through holes 98 penetrating each wall in the thickness direction at the left end of the upper bottom wall 94, the upper front wall 96a, and the upper rear wall 96b, and at the upper left wall 96c. The size of each of these through holes 98 is not limited, but it is preferable that the opening width dimension A (see FIG. 5) of each of the through holes 98 is, for example, 3 mm or more. Similarly, it is preferable that the opening width dimension of each of the through holes 98 formed in the left part of the negative electrode upper case 90 and constituting the first intake hole 44, the second intake hole 48, and the second exhaust hole 50 is, for example, 3 mm or more.

[0049] <Lower case for negative pole 92> The negative electrode lower case 92 is generally box-shaped and opens upward, and includes a bottom wall 100 and a lower peripheral wall 102 that protrudes upward from the outer periphery of the bottom wall 100. The negative electrode lower case 92 is formed with a size in which the left-right dimension is larger than the front-rear dimension. When the negative electrode upper case 90 and the negative electrode lower case 92 are assembled, the open end of the lower peripheral wall 102 and the open end of the upper peripheral wall 96 are butted against each other in the vertical direction, so that the upper opening of the lower peripheral wall 102 is covered by the negative electrode upper case 90. The negative electrode lower case 92 may hold, for example, a plurality of nuts (not shown) in a substantially embedded state.

[0050] The method of fixing the negative electrode upper case 90 and the negative electrode lower case 92 shaped as described above is not limited, but the upper case 90 and the lower case 92 can be fixed, for example, by locking engagement using projections and recesses provided at corresponding positions on the upper peripheral wall portion 96 and the lower peripheral wall portion 102. Furthermore, the upper peripheral wall portion 96 and / or the lower peripheral wall portion 102 of the negative electrode case 36a may have insertion holes formed therein that penetrate each wall portion in the thickness direction, through which external electric wires (not shown) connected to the external connection portions 78, 80 and the fan drive portion 42 are inserted.

[0051] <First and second fan motors 38, 40> Known fan motors may be used for both the first and second fan motors 38, 40, and blades (not shown) provided inside rotate about central axes L and M, respectively, to generate airflows from one axial direction to the other of the fan motors 38, 40. The first and second fan motors 38, 40 may, for example, be of the same shape and arranged in opposite directions, so that airflows are generated from the fan motors 38, 40 in opposite directions.

[0052] In the first embodiment, the first fan motor 38 is provided to the right of the second fan motor 40, and the first fan motor 38 generates an airflow (airflow direction α) from left to right, while the second fan motor 40 generates an airflow (airflow direction β) from right to left. In particular, in the first embodiment, as shown in FIG. 4, the central axes L and M of the fan motors 38 and 40 are located approximately in the center of the negative pole circuit unit 10a in the front-rear direction in a plan view, and the fan motors 38 and 40 are arranged approximately coaxially. By arranging the fan motors 38 and 40 having the same shape as each other in this way at a predetermined distance from each other, it is possible to avoid problems such as airflow being generated mainly in one fan motor and insufficient airflow being generated in the other fan motor.

[0053] In the first embodiment, in the negative pole circuit unit 10a, the first fan motor 38 is provided to the left of the fuse 54, and is located to the left of the relays 52 and fuse 54, which are the heat generating components 14. In other words, in the negative pole circuit unit 10a, the relays 52 and fuse 54, which are the heat generating components 14, are arranged downstream (to the right) of the first fan motor 38 in the air blowing direction α, and are not arranged upstream of the first fan motor 38. That is, the heat sinks 62 fixed above the relays 52 are also arranged downstream (to the right) of the first fan motor 38 in the air blowing direction α.

[0054] Specifically, in the negative pole circuit unit 10a, a space extending from the first fan motor 38 toward the downstream side is an airflow path 104 (shown by a two-dot chain line in FIG. 5) in which an airflow is generated as the blades of the first fan motor 38 rotate. Meanwhile, in the negative pole circuit unit 10a, an intake area 106 (shown by a two-dot chain line in FIG. 4) is formed between the opposing surfaces of the first fan motor 38 and the second fan motor 40, and the air in the intake area 106 is blown downstream as the blades of the first and second fan motors 38, 40 rotate.

[0055] The airflow path 104 is, for example, an area surrounded by the negative pole case 36a (negative pole upper case 90 and negative pole lower case 92) in the negative pole circuit unit 10a. In the first embodiment, the airflow path 104 extends in the left-right direction downstream of the first fan motor 38 with a substantially constant cross-sectional area (cross-sectional area in a cross section perpendicular to the left-right direction). This allows air to flow in the airflow path 104 with a substantially constant cross-sectional area. In particular, in the first embodiment, in the airflow path 104 in the negative pole circuit unit 10a, the fuse 54 with a relatively small amount of heat generation is disposed on the upstream side (left side), and the relays 52 with a relatively large amount of heat generation are disposed on the downstream side (right side).

[0056] On the other hand, as described above, the second fan motor 40 is provided at the left end portion of the negative pole circuit unit 10a, and the rotation of the blade portion around the central axis M generates an airflow (airflow direction β) from right to left. That is, the second fan motor 40 blows air in the intake area 106 to the left of the negative pole circuit unit 10a through the second exhaust hole 50 provided at the left end of the negative pole circuit unit 10a. Therefore, the second fan motor 40 is disposed so that the intake side of the second fan motor 40 faces the first fan motor 38, separated from the first fan motor 38 upstream in the airflow direction α of the first fan motor 38.

[0057] The above-mentioned first and second fan motors 38, 40, with a plurality of blades (not shown) housed in a case, are fixedly supported by a support frame 108, for example, by bolts. These support frames 108 are then fixed to the negative pole lower case 92, for example, by bolts, so that each of the fan motors 38, 40 is fixedly provided to the negative pole case 36a.

[0058] <The other circuit unit (positive electrode circuit unit 10b)> The positive circuit unit 10b, which is the other circuit unit of the pair of circuit units 10, is shown in FIG. 8. As described above, the positive circuit unit 10b includes a positive circuit configuration part 34b including the heat generating component 14, and a positive case 36b that houses the positive circuit configuration part 34b. The basic structure of the positive circuit unit 10b is similar to that of the negative circuit unit 10a, and only a brief description of the positive circuit unit 10b will be given. In the positive circuit unit 10b, the same members and parts as those of the negative circuit unit 10a are denoted in the figure by the same reference numerals as those of the negative circuit unit 10a.

[0059] The positive-pole circuit unit 34b also includes a relay 52 as a first heat-generating component and a fuse 54 as a second heat-generating component as the heat-generating component 14. In the first embodiment, two relays 52, 52 are provided at a distance from each other in the left-right direction in the left part of the positive-pole circuit unit 10b. A heat sink 62 is thermally connected to each terminal portion 58 of each relay 52. ​​The heat sinks 62 are provided at approximately the same position in the front-rear direction and are continuous with each other in the left-right direction. The current-carrying bus bars 72d to 72g are connected to each terminal portion 58 of each relay 52 by bolts not shown, and each relay 52 and each heat sink 62 are fixed via each current-carrying bus bar 72d to 72g and each insulating heat-conducting sheet 70. As a result, heat generated by each relay 52 is transmitted to each heat sink 62 via each current-carrying bus bar 72d to 72g and each insulating heat-conducting sheet 70.

[0060] Further, a precharge relay 109 and a precharge resistor 110 are provided on the rear side of the right portion of the positive circuit unit 10b. The fuse 54, the precharge relay 109, and the precharge resistor 110 provided on the right portion of the positive circuit unit 10b each generate less heat than the respective relays 52 provided on the left portion of the positive circuit unit 10b.

[0061] <Circuit configuration unit 34 (positive pole circuit configuration unit 34b)> In the first embodiment, the positive pole circuit configuration section 34b in the positive pole circuit unit 110b is configured to include the relays 52 which are the first heat generating components, the fuse 54 which is the second heat generating component, the current carrying bus bars 72b to 72g, the pre-charge relay 109, and the pre-charge resistor 110. The heat dissipation bus bars 84 are fixed to the current carrying bus bars 72b to 72g by bolts (for example, bolts 76). The heat dissipation section 86 of each heat dissipation bus bar 84 is overlapped with a positive pole lower case 114 (described later) which constitutes the case 36 (positive pole case 36b) via the insulating heat conductive sheets 88.

[0062] <Case 36 (Case 36b for positive pole)> The positive electrode case 36b is generally in the shape of a hollow rectangular parallelepiped, and is configured to include a positive electrode upper case 112 and a positive electrode lower case 114 that can be assembled and disassembled relative to each other in the vertical direction. The positive electrode upper case 112 and the positive electrode lower case 114 are formed of, for example, synthetic resin.

[0063] <Positive pole upper case 112> The positive electrode upper case 112 has the same shape as the negative electrode upper case 90, and includes an upper bottom wall portion 94 and an upper peripheral wall portion 96 that protrudes downward from the outer periphery of the upper bottom wall portion 94. The upper peripheral wall portion 96 includes an upper front wall portion 96a, an upper rear wall portion 96b, an upper left wall portion 96c, and an upper right wall portion 96d.

[0064] <Positive pole lower case 114> The positive electrode lower case 114 has a shape similar to that of the negative electrode lower case 92, and includes a bottom wall portion 100 and a lower peripheral wall portion 102 protruding upward from the outer peripheral edge portion of the bottom wall portion 100. The positive electrode upper case 112 and the positive electrode lower case 114 may be fixed to each other by a locking fit using projections and recesses, or may be fixed to each other by other known fixing means. The positive electrode case 36b may be formed with an electric wire insertion hole through which an external electric wire (not shown) is inserted, similar to the negative electrode case 36a. This electric wire insertion hole may be provided in the positive electrode upper case 112, or may be provided across both the positive electrode upper case 112 and the positive electrode lower case 114.

[0065] <Other-side intake hole 116 and other-side exhaust hole 118> The positive pole case 36b in the positive pole circuit unit 10b is provided downstream (left) in the air blowing direction β of the second fan motor 40, and the air blown by the second fan motor 40 passing through the second exhaust hole 50 passes through the other-side intake hole 116 provided in the positive pole case 36b. Also, the other-side exhaust hole 118 is provided downstream (left) of the other-side intake hole 116 in the air blowing direction β of the second fan motor 40 in the positive pole case 36b.

[0066] Specifically, the other-side intake hole 116 is provided at the right end of the positive pole case 36b, and the other-side exhaust hole 118 is provided at the left end of the positive pole case 36b. In the first embodiment, both the other-side intake hole 116 and the other-side exhaust hole 118 are provided in the positive pole upper case 112 of the positive pole case 36b. As described later, air that flows into the positive pole circuit unit 10b through the other-side intake hole 116 is exhausted to the outside of the positive pole circuit unit 10b through the other-side exhaust hole 118. Therefore, in the positive pole circuit unit 10b, substantially the entire internal space of the positive pole circuit unit 10b is the air blowing path 119.

[0067] The heat generating components 14 (relays 52, fuse 54, precharge relay 109, and precharge resistor 110) in the positive pole circuit unit 10b are disposed between the other side air intake hole 116 and the other side exhaust hole 118 in the air blowing direction β of the second fan motor 40. In the first embodiment, also in the positive pole circuit unit 10b, the fuse 54, precharge relay 109, and precharge resistor 110, which generate a relatively small amount of heat, are disposed on the upstream side (right side) of the air blowing path 119, and the relays 52, which generate a relatively large amount of heat, are disposed on the downstream side (left side). Also, the heat sinks 62 fixed above the relays 52 are disposed downstream (left side) of the second fan motor 40 in the air blowing direction β.

[0068] The other-side intake hole 116 and the other-side exhaust hole 118 are formed of a plurality of through holes 120 that penetrate each wall of the positive electrode upper case 112 in the thickness direction. The plurality of through holes 120 are aligned in the front-rear and / or left-right directions. In short, the other-side intake hole 116 is formed of a plurality of through holes 120 that penetrate each wall in the thickness direction at the right end of the upper bottom wall 94, the upper front wall 96a, and the upper rear wall 96b, and at the upper right wall 96d. The other-side exhaust hole 118 is formed of a plurality of through holes 120 that penetrate each wall in the thickness direction at the left end of the upper bottom wall 94, the upper front wall 96a, and the upper rear wall 96b, and at the upper left wall 96c.

[0069] As described above, the pair of circuit units 10 (negative and positive circuit units 10a, 10b) are disposed in the front portion of the housing body 24. Specifically, as also shown in Fig. 2, the exhaust direction regulating portion 30 (negative and positive exhaust direction regulating portions 30a, 30b) described above is provided in the front portion of the housing body 24, and the circuit units 10a, 10b are disposed between the exhaust direction regulating portions 30a, 30b and the front wall portion of the housing body 24.

[0070] The negative and positive circuit units 10a and 10b are disposed in a relatively close relationship with the second exhaust hole 50 in the negative circuit unit 10a and the other-side intake hole 116 in the positive circuit unit 10b facing each other, and are spaced apart slightly from each other. As described above, the negative circuit unit 10a has a longer length dimension in the left-right direction than the positive circuit unit 10b, and the second exhaust hole 50 provided at the left end of the negative circuit unit 10a is located to the left of the left-right center of the housing body 24. In the first embodiment, the intake area 106 between the first fan motor 38 and the second fan motor 40 in the negative circuit unit 10a is located in the left-right center of the housing body 24.

[0071] The first exhaust hole 46 in the negative electrode circuit unit 10a and the other-side exhaust hole 118 in the positive electrode circuit unit 10b are disposed facing the wall portions on both the left and right sides of the housing main body 24. That is, the first exhaust hole 46 and the other-side exhaust hole 118 are disposed on the peripheral portions on both the left and right sides of the housing main body 24.

[0072] <Assembly of a pair of circuit units 10 (negative and positive circuit units 10a, 10b)> A specific example of a method for assembling the negative and positive circuit units 10a, 10b will be described below. Note that the method for assembling the negative and positive circuit units 10a, 10b is not limited to the embodiment described below.

[0073] First, the assembly method of the negative pole circuit unit 10a will be described. First, the relays 52 and the fuses 54 are bolted to the negative pole lower case 92 together with the current-carrying bus bars 72b to 72g and the heat-dissipating bus bars 84. The insulating heat-conducting sheets 88 are provided in advance on the upper surface of the bottom wall portion 100 of the negative pole lower case 92 and / or the lower surface of the heat-dissipating portion 86 of the heat-dissipating bus bars 84. The heat sinks 62 are overlapped with the portions 72a of the current-carrying bus bars 72d to 72g that cover the relays 52 via the insulating heat-conducting sheets 70, and are fixed by bolts or the like. The first and second fan motors 38, 40 are fixed to the negative pole lower case 92 via the support frame 108, and the fan drive unit 42 is housed and fixed in the negative pole lower case 92. Thereafter, the fan drive unit 42 and the first and second fan motors 38, 40 are electrically connected by the electric wires 82. Next, the negative pole upper case 90 is brought close from above and the negative pole upper case 90 and the negative pole lower case 92 are fixed together, completing the negative pole circuit unit 10a.

[0074] Next, a method of assembling the positive circuit unit 10b will be described. First, the relays 52 and fuses 54 are bolted to the positive lower case 114 together with the current-carrying bus bars 72b to 72g and the heat-dissipating bus bars 84. Note that insulating heat-conducting sheets 88 are provided in advance on the upper surface of the bottom wall portion 100 of the positive lower case 114 and / or the lower surface of the heat-dissipating portion 86 of each heat-dissipating bus bar 84. Also, each heat sink 62 is superimposed on the portion 72a of each current-carrying bus bar 72d to 72g that covers each relay 52 via the insulating heat-conducting sheet 70, and is fixed by bolts or the like. Thereafter, the pre-charge relay 109 and the pre-charge resistor 110 are electrically connected to a predetermined current-carrying bus bar 72. Next, the positive pole upper case 112 is brought close from above to fix the positive pole upper case 112 and the positive pole lower case 114 together, thereby completing the positive pole circuit unit 10b. In addition, the pair of circuit units 10 is completed.

[0075] These negative and positive circuit units 10a, 10b are disposed in the housing body 24 in which the exhaust direction regulating units 30a, 30b are provided, between the exhaust direction regulating units 30a, 30b and the front wall of the housing body 24. In this manner, the housing body 24 in which the negative and positive circuit units 10a, 10b are provided contains a plurality of battery cells 18 and a BMS board 22, which are electrically connected to each other, and an upper opening 26 in the housing body 24 is covered with a lid 28, thereby forming the battery pack 12.

[0076] In this battery pack 12, for example, when the fan drive unit 42 detects that the temperature inside the negative electrode circuit unit 10a exceeds a predetermined temperature, a fan drive signal is sent to the first and second fan motors 38, 40 to drive the first and second fan motors 38, 40. Alternatively, for example, when the BMS board 22 detects that the temperature inside the battery pack 12 exceeds a predetermined temperature, a signal for driving the first and second fan motors 38, 40 is sent to the first and second fan motors 38, 40 via the fan drive unit 42 to drive the first and second fan motors 38, 40.

[0077] Here, in the negative pole circuit unit 10a, by driving the first fan motor 38, air is sucked from the outside of the negative pole circuit unit 10a through the first intake hole 44 into the intake area 106, and the air in the intake area 106 is blown in the direction of the blowing direction α by the first fan motor 38. When the air blown by the first fan motor 38 reaches the right end of the negative pole circuit unit 10a, it is discharged to the outside of the negative pole circuit unit 10a through the first exhaust hole 46. The air discharged from the first exhaust hole 46 is changed in direction by the inclined surface 32 of the exhaust direction regulating part 30a for the negative pole, and flows in a direction (forward) away from the battery cell 18. Then, the air changed in direction by the inclined surface 32 flows inward in the left-right direction (leftward) between the negative pole circuit unit 10a and the front wall part of the housing main body 24, and returns to the center of the housing main body 24 in the left-right direction. The air that has returned to the center in the left-right direction of the housing body 24 is again drawn into the intake area 106 through the first intake hole 44 and circulates.

[0078] In addition, in the negative pole circuit unit 10a, by driving the second fan motor 40, air is drawn from the outside of the negative pole circuit unit 10a into the intake area 106 through the second air intake hole 48, and the air in the intake area 106 is blown in the air blowing direction β by the second fan motor 40. The air blown by the second fan motor 40 is exhausted through the second exhaust hole 50, and flows into the positive pole circuit unit 10b through the other side air intake hole 116 in the positive pole circuit unit 10b located opposite the second exhaust hole 50.

[0079] The air that flows into the positive circuit unit 10b through the other-side intake hole 116 is blown in the direction of airflow β, and when it reaches the left end of the positive circuit unit 10b, it is discharged to the outside of the positive circuit unit 10b through the other-side exhaust hole 118. The air discharged from the other-side exhaust hole 118 is redirected by the inclined surface 32 of the positive exhaust direction regulating portion 30b, and moves in a direction (forward) away from the battery cell 18. The air that has been redirected by the inclined surface 32 flows inward in the left-right direction (rightward) between the positive circuit unit 10b and the front wall of the housing body 24, and returns to the left-right center of the housing body 24. The air that has returned to the left-right center of the housing body 24 is again drawn into the intake area 106 through the second intake hole 48, and circulates.

[0080] Each of the circuit components 34a, 34b in each of the circuit units 10a, 10b has the heat-generating components 14, such as the relays 52 and fuses 54, and these components, which generate heat when energized, are cooled by the air blown by the first and second fan motors 38, 40. In particular, in the first embodiment, exhaust direction restriction units 30a, 30b are provided to restrict the direction of exhaust from each of the circuit units 10a, 10b, and the air heated by passing through each of the circuit units 10a, 10b is redirected by the inclined surfaces 32 and flows in a direction away from the battery cells 18. This makes it possible to more reliably prevent the air heated by the heat-generating components 14 (such as the relays 52 and fuses 54) from flowing toward the battery module 16 (each battery cell 18) and adversely affecting the battery module 16. The air discharged from the first exhaust hole 46 and the other-side exhaust hole 118 can be cooled by contacting the wall of the housing body 24 of the battery pack 12, and the air discharged from the first exhaust hole 46 and the other-side exhaust hole 118 can be drawn in at a lower temperature from the first and second intake holes 44, 48. As a result, the heat generated in the heat-generating component 14 can be cooled more efficiently.

[0081] In such a pair of circuit units 10 (each circuit unit 10a, 10b), one circuit unit (negative pole circuit unit 10a) accommodates a first fan motor 38 and a second fan motor 40 that generate airflow (airflow directions α, β) flowing through each circuit unit 10a, 10b, and a fan drive unit 42 that drives them. This allows the number of electric wires (wire harnesses) and the like to be reduced, and the number of assembly steps to be reduced, compared to a case where a fan motor and a fan drive unit are provided in each circuit unit. In addition, since electric wires (wire harnesses) and the like do not extend across each circuit unit 10a, 10b, the structure of each circuit unit 10a, 10b can be simplified.

[0082] In each of the circuit units 10a and 10b, a heat sink 62 is thermally connected to each relay 52, which is a heat generating component 14, and each heat sink 62 is disposed downstream of the first fan motor 38 and the second fan motor 40 in the air blowing directions α and β. As a result, heat generated in each relay 52 is transferred to each heat sink 62, and the heat is effectively dissipated by the air blown by the first and second fan motors 38 and 40. In particular, in the first embodiment, in the air blowing paths 104 and 119 of the air blown by the first and second fan motors 38 and 40, the fuse 54 and the like, which generate a relatively small amount of heat, are disposed upstream of the air blowing directions α and β, and each relay 52, which generate a relatively large amount of heat, is disposed downstream of the air blowing directions α and β. Therefore, the air is not heated by the relays upstream of each air blowing path 104 and 119, and it is possible to prevent relatively high-temperature air from flowing downstream of each air blowing path 104 and 119. In other words, relatively low temperature air heated by the fuse 54 or the like can be blown toward each relay 52 located downstream of each air blowing path 104, 119, allowing the heat generated in each relay 52 to be dissipated more stably.

[0083] In the negative pole circuit unit 10a, an intake area 106 is formed between the opposing surfaces of the first fan motor 38 and the second fan motor 40, and a plurality of through holes 98 are provided in the area covering the intake area 106 in the negative pole case 36a, and these plurality of through holes 98 are shared to form the first intake hole 44 and the second intake hole 48. This makes it possible to avoid an increase in size of the negative pole circuit unit 10a and to simplify the structure of the negative pole circuit unit 10a, as compared to a case in which the first intake hole 44 and the second intake hole 48 are provided separately.

[0084] In the negative pole circuit unit 10a, the heat generating components 14 (relays 52 and fuses 54) are arranged downstream (to the right) of the first fan motor 38 in the airflow direction α, and are not arranged upstream (to the left) of the first fan motor 38 in the airflow direction α. ​​This prevents the air whose temperature has increased due to heat generation by the heat generating components 14 from being applied to the first fan motor 38. In addition, the air whose temperature has increased by passing through the heat generating components 14 is cooled by contacting the housing main body 24 while being discharged from the first exhaust hole 46 and circulating to the first intake hole 44, so that it is possible to stably prevent high-temperature air from being applied to the first fan motor 38 and adversely affecting the operation of the first fan motor 38.

[0085] <Modification> Although the first embodiment has been described above as a specific example of the present disclosure, the present disclosure is not limited to this specific description. Modifications, improvements, etc. within the scope of achieving the object of the present disclosure are included in the present disclosure. For example, the following modified examples of the embodiment are also included in the technical scope of the present disclosure.

[0086] (1) In the above embodiment, the exhaust direction regulating parts 30a, 30b are provided on the left and right side walls of the housing body 24 of the battery pack 12 as separate parts from the circuit units 10a, 10b, but the present invention is not limited to this embodiment. For example, as in a pair of circuit units 130 (negative electrode circuit unit 130a and positive electrode circuit unit 130b) shown in FIG. 9, the exhaust direction regulating part 132 may be formed integrally with the case 36 (negative electrode case 36a and positive electrode case 36b) of each circuit unit 130a, 130b, or may be formed separately and fixed later. Note that the exhaust direction regulating part is not essential to each circuit unit according to the present disclosure. Also, even if the exhaust direction regulating part is provided in the battery pack as in the above embodiment, it is not limited to the left and right side walls of the housing body, and may be provided on the bottom wall of the housing body or on the lid.

[0087] (2) In the above embodiment, the first and second fan motors 38, 40 and the fan drive unit 42 are provided in the negative pole circuit unit 10a, but the first and second fan motors and the fan drive unit may be provided in the positive pole circuit unit. When the first and second fan motors and the fan drive unit are provided in the negative pole circuit unit, the specific configuration of the positive pole circuit unit is not limited as long as it includes a circuit configuration unit including a heat-generating component and a case that houses the circuit configuration unit and has an air intake hole on the other side and an air exhaust hole on the other side. For example, the heat-generating component may be only one of a relay and a fuse, and a heat dissipation bus bar and a heat sink are not essential.

[0088] (3) In the above embodiment, the fan drive unit 42 also has a monitoring function for monitoring the internal state of the negative electrode circuit unit 10a, but this is not limited to this. That is, as exemplified in the above embodiment, the internal state of the battery pack may be monitored by the BMS board, and when the BMS board detects that the temperature or current value exceeds a predetermined value, a signal for driving the fan may be sent from the BMS board to the fan drive unit, and the fan drive unit may drive the first and second fan motors.

[0089] (4) The first fan motor and the second fan motor do not need to operate simultaneously. For example, the first fan motor and the second fan motor may be operated alternately to blow air alternately to the negative pole circuit unit and the positive pole circuit unit, or the first fan motor and the second fan motor may be operated with a time lag.

[0090] (5) In the above embodiment, the first intake hole 44 and the second intake hole 48 are configured by sharing a plurality of through holes 98. However, the first intake hole and the second intake hole may be provided separately, for example, by providing a partition wall between the first fan motor and the second fan motor. At least one of the first intake hole, the first exhaust hole, the second intake hole, the second exhaust hole, the other-side intake hole, and the other-side exhaust hole is not limited to being formed by a plurality of through holes, and may be formed by one hole portion penetrating the case in the thickness direction. In addition, these intake holes and exhaust holes are not limited to being provided in the upper case constituting the case, and may be provided in the lower case, or may be provided in both the upper case and the lower case.

[0091] (6) In the above embodiment, in the negative pole circuit unit 10a, the heat generating components 14 (relays 52 and fuse 54) are disposed downstream (to the right) of the first fan motor 38 in the airflow direction α, but this is not limited to the above embodiment. For example, in the negative pole circuit unit, the heat generating components may be disposed upstream of the first fan motor in the airflow direction, that is, the heat generating components may be disposed between the first fan motor and the second fan motor. In this case, the heat generating components disposed between the first fan motor and the second fan motor are preferably heat generating components with a small amount of heat, such as fuses. [Explanation of symbols]

[0092] 10 Pair of circuit units (embodiment 1) 10a Negative circuit unit (one of the circuit units) 10b Positive circuit unit (other circuit unit) 12 Battery pack 14 Heat generating parts 16 Battery Module 18 Battery Cells 20. Cabinet 22 BMS board 24 Main unit 26 Upper opening 28 Lid 30 Exhaust direction control part 30a Negative pole exhaust direction control part 30b Exhaust direction control part for positive pole 32 Slope 34 Circuit component 34a Negative pole circuit component 34b Positive circuit component 36 cases 36a Negative pole case 36b Positive pole case 38 No. 1 fan motor 40 Second fan motor 42 Fan drive unit 44 No. 1 air intake 46 First exhaust hole 48 Secondary air intake 50 Secondary exhaust hole 52 Relay (first heat generating component) 54 Fuse (second heat generating component) 56 Case body 58 Terminal section 60 Insulating partition plate 62 Heat sink 64 Plate-shaped part 66 Heat sink 68 Gap 70 Insulating heat conductive sheet 72 Current carrying busbar 72a The portion of the current-carrying busbar that covers the upper part of the relay 72b~72g Current carrying busbars 74 Terminal section 76 Volts 78,80 External connection part 82 Electric wire 84 Heat dissipation bus bar 86 Heat radiation part 88 Insulating heat conductive sheet 90 Negative pole upper case 92 Lower case for negative pole 94 Upper bottom wall 96 Upper peripheral wall 96a Upper front wall 96b Upper rear wall 96c Upper left wall 96d Upper right wall 98 Through Hole 100 Bottom wall 102 Lower peripheral wall 104 Air flow path 106 Intake Area 108 Support Frame 109 Precharge Relay 110 Precharge resistor 112 Positive pole upper case 114 Positive pole lower case 116 Other side intake port 118 Other side exhaust hole 119 Air flow path 120 Through hole 130 Pair of circuit units (another embodiment) 130a Negative circuit unit 130b Positive circuit unit 132 Exhaust direction control part α,β Air blowing direction L,M center axis

Claims

1. A pair of circuit units housed in a housing of a battery pack, Each of the circuit units includes: A circuit configuration unit including a heat generating component; a case that houses the circuit configuration unit, One of the pair of circuit units is a first fan motor and a second fan motor; a fan drive unit provided in the circuit configuration unit and configured to drive the first fan motor and the second fan motor; the case of the one circuit unit has a first intake hole provided upstream in the air blowing direction of the first fan motor, a first exhaust hole provided downstream in the air blowing direction of the first fan motor, a second intake hole provided upstream in the air blowing direction of the second fan motor, and a second exhaust hole provided downstream in the air blowing direction of the second fan motor, the heat generating component of the one circuit unit is disposed downstream of the first fan motor and upstream of the first exhaust hole in the air blowing direction of the first fan motor, the case of the other circuit unit is provided downstream in the air blowing direction of the second fan motor and has a second-side intake hole through which air blown by the second fan motor passing through the second exhaust hole passes, and a second-side exhaust hole disposed downstream of the second-side intake hole in the air blowing direction of the second fan motor, A pair of circuit units, the heat-generating component of the other circuit unit being disposed between the other air intake hole and the other air exhaust hole in the air blowing direction of the second fan motor.

2. a heat sink thermally connected to each of the heat generating components; The pair of circuit units according to claim 1 , wherein each of the heat sinks is disposed on the downstream side of the first fan motor or the second fan motor in the air blowing direction.

3. the second fan motor is disposed upstream of the first fan motor in the air blowing direction of the first fan motor, and an intake side of the second fan motor faces the first fan motor; 3. A pair of circuit units as described in claim 1 or claim 2, wherein an intake area is defined between opposing surfaces of the first fan motor and the second fan motor, and a plurality of through holes are provided in an area covering the intake area in the case of one of the circuit units, and the first intake hole and the second intake hole are defined by sharing the plurality of through holes.

4. 3. A pair of circuit units according to claim 1 or claim 2, wherein the heat-generating component of one of the circuit units is arranged downstream of the first fan motor in the air blowing direction, and is not arranged upstream of the first fan motor.

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