Circuit unit

Abstract

To provide a circuit unit that is accommodated in a housing of a battery pack which enables reduction in the number of parts and the number of assembling steps.SOLUTION: A circuit unit 10 is housed in a housing 20 of a battery pack 12, and includes a circuit configuration section 38 configured to include at least one of a temperature sensor 36 and a current sensor 37, and a drive component 40 to be driven with electric power from the circuit configuration section 38. The circuit configuration section 38 has a drive section 42 for switching ON / OFF of the drive power of the drive component 40, and the drive section 42 switches ON / OFF of the drive power of the drive component 40 according to a detection value of at least one of the temperature sensor 36 and the current sensor 37.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a circuit unit. [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 fan motor and equipped with heat-generating components 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 cases, the fan motor mounted on the circuit unit is driven, for example, during quick charging or when a current of a certain level or more flows, and therefore it is necessary to route and assemble a wire harness including electric wires for the fan motor's driving power supply and control signals from a BMS (Battery Management System) or the like mounted in the same battery pack to the circuit unit, resulting in an increase in the number of parts and assembly man-hours.

[0005] Therefore, a circuit unit that is housed within the housing of a battery pack is disclosed, which enables a reduction in the number of parts and assembly steps. [Means for solving the problem]

[0006] The circuit unit of the present disclosure is a circuit unit housed within a battery pack housing, and comprises a circuit configuration section including at least one of a temperature sensor and a current sensor, and a driving component driven by power from the circuit configuration section, wherein the circuit configuration section has a driving section that switches the driving power of the driving component ON / OFF, and the driving section switches the driving power of the driving component ON / OFF depending on the detection value of at least one of the temperature sensor and the current sensor. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a circuit unit that is accommodated in a battery pack housing, which enables a reduction in the number of parts and assembly steps. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a battery pack including a circuit unit according to the first embodiment with a lid that constitutes 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 the circuit unit 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 an enlarged plan view showing a main part of a battery pack including a circuit unit according to another embodiment of the present disclosure, 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 circuit unit of the present disclosure includes: (1) A circuit unit housed within a battery pack housing, comprising a circuit configuration section including at least one of a temperature sensor and a current sensor, and a driving component driven by power from the circuit configuration section, wherein the circuit configuration section has a driving section that switches the driving power of the driving component ON / OFF, and the driving section switches the driving power of the driving component ON / OFF in response to the detection value of at least one of the temperature sensor and the current sensor.

[0010] According to this aspect, in the circuit unit housed in the housing of the battery pack, at least one of a temperature sensor and a current sensor is mounted on the circuit configuration section, and the driving power of the driving parts driven by the power from the circuit configuration section can be turned on and off by the driving section mounted on the circuit configuration section. Moreover, the driving section is configured to switch on and off the driving power of the driving parts depending on the detection value of the temperature sensor and / or the current sensor mounted on the same circuit configuration section. Therefore, the driving control of the driving parts can be performed completely by the circuit configuration section mounted on the circuit unit, and the process of routing and assembling a wire harness including electric wires for the driving power source and control signals of the driving parts to the circuit unit, which was required in the conventional structure, can be eliminated. As a result, it is possible to provide a circuit unit housed in the housing of a battery pack that can reduce the number of parts and the number of assembly steps.

[0011] The driving component may be any driving component whose drive is controlled by the detection values ​​of a temperature sensor or a current sensor mounted on the circuit configuration section of the circuit unit, such as a fan motor that cools a heat-generating component mounted on the circuit unit.

[0012] (2) In the above (1), it is preferable that the circuit configuration includes a heat-generating component, and the driving component is a fan motor that promotes cooling of the heat-generating component. In many cases, the circuit configuration of the circuit unit housed in the battery pack includes heat-generating components such as relays and fuses, and a fan motor, which is a driving component, may be mounted to cool the heat-generating component. In such a case, the fan motor can be switched ON / OFF according to the detection values ​​of a temperature sensor or a current sensor mounted on the circuit configuration. As a result, in addition to reducing the number of components and assembly steps, it is possible to realize more appropriate driving of the fan motor according to the temperature and current value in the circuit unit, which can also contribute to improving the operational stability of the circuit unit.

[0013] (Subsequent paragraph numbering changed) (3) In the above (2), it is preferable that the heat generating component includes a first heat generating component thermally connected to a heat sink, and the first heat generating component and the heat sink are disposed downstream of the fan motor in the air blowing direction of the fan motor. Heat generated by the heat generating component is efficiently transferred to the heat sink from the terminal portion, where heat is most transferred, 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.

[0014] (4) In the above (3), it is preferable that the heat generating component includes a second heat generating component arranged upstream of the fan motor in the airflow direction, and the heat generation amount of the second heat generating component is smaller than the heat generation amount of the first heat generating component. There are cases where the fan motor cannot be arranged at the end of the circuit unit due to requirements such as space and circuit configuration in the battery pack. Even in such a case, by arranging the second heat generating component, which generates a smaller heat generation amount than the first heat generating component, upstream of the fan motor in the airflow direction, it is possible to efficiently dissipate heat from the first heat generating component, which generates a larger heat generation amount, by utilizing the airflow from the fan motor while satisfactorily satisfying the conditions on the intake side of the fan motor.

[0015] (5) In any one of the above (2) to (4), it is preferable that the fan motor includes a suction path extending from the upstream side of the fan motor toward the fan motor and a blowing path extending from the fan motor toward the downstream side in the blowing direction of the fan motor, and the cross-sectional area in the direction perpendicular to the blowing direction is constant in the entire region from the suction path to the blowing path. The cross-sectional area in the direction perpendicular to the blowing direction is constant in the entire region from the suction path upstream of the fan motor to the blowing path downstream of the fan motor. As a result, air flows with a constant cross-sectional area from the suction path to the blowing path, and it is possible to prevent the occurrence of parts where the air is difficult to flow, and to prevent, for example, a local temperature rise in a circuit unit. In particular, in combination with the above (3) or (4), when a first heat-generating component and a heat sink are arranged in the blowing path or a second heat-generating component is arranged in the suction path, the flow of air in these paths is stable, and heat dissipation in the first heat-generating component and the second heat-generating component can be stably realized.

[0016] (6) In any one of the above (1) to (5), it is preferable that the driving unit turns on the driving power of the driving part when the detection value of the temperature sensor exceeds a predetermined temperature, and turns off the driving power of the driving part when the detection value of the temperature sensor falls below the predetermined temperature or a predetermined time has passed since the driving of the driving part. As a specific example of a manner in which the driving unit switches on / off the driving power of the driving part, for example, a manner in which the driving power of the driving part is turned on when the detection value of the temperature sensor exceeds a predetermined temperature, and the driving power of the driving part is turned off when the detection value of the temperature sensor falls below the predetermined temperature or a predetermined time has passed since the driving of the driving part is. In other words, the switching on / off of the driving power of the driving part by the driving unit in response to the detection value of the temperature sensor may be only from OFF to ON, and the switching of the driving power of the driving part from ON to OFF may not be in response to the detection value of the temperature sensor.

[0017] (7) In any one of the above (1) to (6), it is preferable that the driving unit turns on the driving power of the driving part when the detection value of the current sensor exceeds a predetermined value, and turns off the driving power of the driving part when the detection value of the current sensor becomes smaller than the predetermined value or when a predetermined time has passed since the driving of the driving part. As a specific example of a manner in which the driving unit switches on / off the driving power of the driving part, for example, a manner in which the driving power of the driving part is turned on when the detection value of the current sensor exceeds a predetermined value, and the driving power of the driving part is turned off when the detection value of the current sensor becomes smaller than the predetermined value or when a predetermined time has passed since the driving of the driving part. In other words, the switching on / off of the driving power of the driving part by the driving part in response to the detection value of the current sensor may be only from OFF to ON, and the switching of the driving power of the driving part from ON to OFF may not be in response to the detection value of the current sensor.

[0018] <Details of the embodiment of the present disclosure> Specific examples of the circuit unit of 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.

[0019] <Embodiment 1> Hereinafter, the circuit unit 10 according to the first embodiment of the present disclosure will be described with reference to Figs. 1 to 7. The circuit unit 10 is 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 the heat generated by the heat generating components 14 provided inside the circuit unit 10. The battery pack 12 can be arranged in any direction in the vehicle, but in the following, the upper side will be described as the front side in the direction perpendicular to the paper surface in Fig. 2 (upper side in Fig. 5), the lower side will be described as the rear side in the direction perpendicular to the paper surface in Fig. 2 (lower side in Fig. 5), the left side will be described as the left side in Fig. 2, the right side will be described as the right side in Fig. 2, the front side will be described as the lower side in Fig. 2, and the rear side will be described as the upper side in Fig. 2. In addition, for multiple identical members, only some of the members will be labeled with reference numerals, and the reference numerals may be omitted for the other members.

[0020] <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.

[0021] 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.

[0022] 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 an 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 accommodated 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 circuit unit 10 is mounted between the battery module 16 and the front wall of the housing body 24.

[0023] In the first embodiment, in the battery pack 12, an electric connection box 30 is provided to the left of the circuit unit 10, and exhaust direction regulating parts 32, 32 that regulate the direction of exhaust air that has passed through the circuit unit 10 and the electric connection box 30 are provided outward in the left-right direction from the circuit unit 10 and the electric connection box 30. In particular, in the first embodiment, these exhaust direction regulating parts 32 are formed integrally with the housing main body 24, and each exhaust direction regulating part 32 is formed to protrude inward in the left-right direction from the wall parts on both the left and right sides of the housing main body 24. Each exhaust direction regulating part 32 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 34 that is inclined with respect to the left-right direction and the front-rear direction.

[0024] <Circuit unit 10> The circuit unit 10 includes a circuit configuration section 38 configured to include at least one of a temperature sensor 36 and a current sensor 37 (both the temperature sensor 36 and the current sensor 37 in the first embodiment), and a driving component that is driven by power from the circuit configuration section 38. In the first embodiment, the circuit configuration section 38 includes a heat-generating component 14, and the driving component is a fan motor 40 that promotes cooling of the heat-generating component 14. The circuit configuration section 38 also has a microcomputer 42 as a driving section that switches ON / OFF the driving power of the fan motor 40, which is the driving component.

[0025] In the first embodiment, the circuit unit 10 is electrically connected to a negative electrode of the battery module 16 (bus bar module connecting each battery cell 18) via an electric wire or the like (not shown), and the electrical junction box 30 is electrically connected to a 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 circuit unit 10 is provided on the right side of the battery pack 12, and the electrical junction box 30 is provided on the left side of the battery pack 12. The circuit unit 10 and the electrical junction box 30 are each rectangular parallelepiped-shaped and are arranged inside the housing main body 24 so as to extend in the left-right direction.

[0026] <Heat generating component 14 (relay 44 and fuse 46)> In the circuit unit 10, the heat generating component 14 includes a relay 44 as a first heat generating component and a fuse 46 as a second heat generating component. In the first embodiment, two relays 44, 44 are provided at a right portion of the circuit unit 10, spaced apart from each other in the left-right direction. Each relay 44 has a case body 48 having a substantially hollow rectangular box shape, and a pair of terminals 50, 50 are exposed from the case body 48 at the front side of each relay 44 (the front side of the right relay 44, and the rear side of the left relay 44) at a distance from each other in the left-right direction. In each case body 48, an insulating partition plate 52 is provided between the terminals 50, 50 to separate the terminals 50.

[0027] A heat sink 54 is thermally connected to each terminal portion 50 of each relay 44. In the first embodiment, two heat sinks 54, 54 are provided with a gap between them in the left-right direction. As shown in FIG. 4, each heat sink 54 is substantially rectangular in plan view, and each heat sink 54 has a plate-shaped portion 56 extending in the horizontal direction (direction perpendicular to the up-down direction) at its lower end. Each heat sink 54 has a plurality of heat sinks 58 protruding upward from the plate-shaped portion 56, and each heat sink 58 is arranged in parallel and spaced apart from each other in the front-rear direction, and extends in the left-right direction. As a result, a gap 60 extending in the left-right direction is provided between each heat sink 58 in the front-rear direction.

[0028] 6, 7, etc., energizing bus bars 64d-64g (described later) constituting the circuit configuration unit 38 are connected to the terminal portion 50 of each relay 44 by bolts (not shown). These energizing bus bars 64d-64g extend upward from the fixed portions with the respective terminal portions 50, and then bend inward in the front-rear direction to cover the upper portions of the respective relays 44. Each heat sink 54 is fixed to a portion 64a of each of the energizing bus bars 64d-64g covering the upper portions of the respective relays 44 via an insulating heat conductive sheet 62.

[0029] Each insulating heat conductive sheet 62 is a sheet-like member having electrical insulation and good thermal conductivity, and a known one may be used. Each insulating heat conductive sheet 62 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 64a of each current-carrying busbar 64d to 64g covering the upper part of each relay 44 and the heat sink 54 may be fixed with an adhesive or bolts via each insulating heat conductive sheet 62, or both an adhesive and bolts may be used. As a result, each relay 44 and each heat sink 54 are fixed via each current-carrying busbar 64d to 64g and each insulating heat conductive sheet 62, and each heat sink 54 is thermally connected to each terminal portion 50.

[0030] Furthermore, a fuse 46 is provided as a second heat generating component on the rear side of the left portion of the circuit unit 10. The fuse 46 in the circuit unit 10 may be, for example, a pyro fuse. The amount of heat generated by this fuse 46 when energized is smaller than that of each of the relays 44, that is, the amount of heat generated by the second heat generating component (fuse 46) is smaller than that of the first heat generating component (relays 44).

[0031] <Circuit configuration section 38> The relays 44 and the fuses 46 are electrically connected by a plurality of current-carrying bus bars 64. That is, the current-carrying bus bar 64 is overlapped with a pair of terminal portions 66, 66 of the fuse 46 and each terminal portion 50 of each relay 44, and is fixed by a bolt 68 (one is shown in FIG. 5). Specifically, the current-carrying bus bar 64b is fixed to the left terminal portion 66 of the fuse 46, and the right terminal portion 66 of the fuse 46 and the left terminal portion 50 of the left relay 44 are connected by current-carrying bus bars 64c, 64d. The right terminal portion 50 of the left relay 44 and the left terminal portion 50 of the right relay 44 are connected by a current-carrying bus bar 64e, and the current-carrying bus bar 64f is fixed to the right terminal portion 50 of the right relay 44. Further, a current supply bus bar 64g, which is separate from the current supply bus bar 64e, is overlapped and fixed to the right terminal portion 50 of the left relay 44 and extends to the right.

[0032] As a result, an external connection portion 70 is formed by the end of the current-carrying bus bar 64b at the left end of the circuit unit 10, and an external connection portion 72 is formed by the ends of the current-carrying bus bars 64f, 64g at the right end of the circuit unit 10. Terminal portions provided at the ends of external electric wires (not shown) are overlapped with these external connection portions 70, 72 and fixed with bolts or the like, so that each of the current-carrying bus bars 64b to 64g and each of the relays 44 and fuses 46 are electrically connected to the external electric wires. Although not limited thereto, for example, the external connection portion 70 is connected to the battery module 16 (particularly the bus bar module) to serve as a connection portion for supplying power to the circuit unit 10, and each of the external connection portions 72 is connected to external electric devices to serve as a connection portion for outputting power to these external electric devices.

[0033] A monitoring and control unit 74 is provided in the left-right middle portion of the circuit unit 10, specifically between the fuse 46 and the left relay 44 in the left-right direction. The monitoring and control unit 74 includes the temperature sensor 36 and the current sensor 37, and the microcomputer 42 as a drive unit. Specifically, the monitoring and control unit 74 is configured by housing a board 76 on which the temperature sensor 36, the current sensor 37, the microcomputer 42, etc. are mounted in a board case 78. The board 76 is electrically connected to the fan motor 40, which is a drive component, via an electric wire or the like (not shown). In the first embodiment, the electric connection box 30 also includes a fan motor (not shown) therein, and the board 76 may also be electrically connected to the fan motor of the electric connection box 30 via an electric wire or the like (not shown).

[0034] That is, in the first embodiment, the temperature sensor 36 in the monitoring and control section 74 monitors the temperature in the circuit unit 10, and when the temperature sensor 36 detects that the temperature has exceeded a predetermined temperature, the microcomputer 42 transmits a drive signal to the fan motor 40 of the circuit unit 10. As a result, the drive power of the fan motor 40 is turned on, and the fan motor 40 is driven. In this case, the microcomputer 42 may transmit a drive signal not only to the fan motor 40 of the circuit unit 10 but also to the fan motor of the electric junction box 30, and drive the fan motor of the electric junction box 30. On the other hand, when the temperature sensor 36 detects that the temperature in the circuit unit 10 has become lower than a predetermined temperature due to the drive of the fan motor 40, the microcomputer 42 transmits a stop signal to the fan motor 40 of the circuit unit 10 and the fan motor of the electric junction box 30. As a result, the drive power of these fan motors is turned off, and these fan motors may be stopped.

[0035] Furthermore, the current sensor 37 in the monitoring and control section 74 monitors the magnitude of the current flowing through the circuit unit 10, and when the current is greater than a predetermined value, the microcomputer 42 transmits a drive signal to the fan motor 40 of the circuit unit 10. As a result, the drive power of the fan motor 40 is turned on, and the fan motor 40 is driven. Therefore, the board 76 in the monitoring and control section 74 is electrically connected to any one of the current-carrying bus bars 64 (current-carrying bus bars 64b to 64g) in the circuit unit 10. The drive signal from the microcomputer 42 may be transmitted not only to the fan motor 40 of the circuit unit 10, but also to the fan motor of the electrical connection box 30. Furthermore, when the current sensor 37 detects that the magnitude of the current flowing through the circuit unit 10 becomes smaller than a predetermined value after the fan motor 40 is driven, the microcomputer 42 transmits a stop signal to the fan motor 40 of the circuit unit 10 and the fan motor of the electrical connection box 30. As a result, the drive power of these fan motors is turned off, and these fan motors may be stopped.

[0036] That is, the microcomputer 42 can turn on the drive power of the fan motor 40 in response to the detection value of at least one of the temperature sensor 36 and the current sensor 37, thereby driving the fan motor 40. The microcomputer 42 may also be configured to turn off the drive power of the fan motor 40 in response to the detection value of at least one of the temperature sensor 36 and the current sensor 37, thereby stopping the fan motor 40, or may be configured to stop the fan motor 40 after a predetermined time has elapsed since the fan motor 40 was driven.

[0037] Alternatively, when the BMS board 22 detects that the temperature or current (or voltage) within the battery pack 12 has exceeded a predetermined value, the BMS board 22 may send a signal to a microcomputer or the like (not shown) that drives the fan motor of the electrical junction box 30, thereby driving the fan motor of the electrical junction box 30.

[0038] Therefore, in the first embodiment, the circuit configuration section 38 in the circuit unit 10 is configured to include the relays 44 which are the first heat-generating components, the fuse 46 which is the second heat-generating component, the current-carrying bus bars 64b to 64g, and the monitoring and control section 74.

[0039] In particular, in the first embodiment, a plurality of heat dissipation busbars 80 are fixed at the fixing points between the terminals 66 of the fuse 46 and the current-carrying busbars 64b, 64c, and at the fixing points between the terminals 50 of the relays 44 and the current-carrying busbars 64d to 64g. Each heat dissipation busbar 80 is substantially L-shaped and has a heat dissipation portion 82 that spreads in the horizontal direction and a portion that protrudes upward from each heat dissipation portion 82. The upward protruding portion of each heat dissipation busbar 80 is fastened together with each current-carrying busbar 64b to 64g to each terminal 66 of the fuse 46 and each terminal 50 of each relay 44 by bolts (for example, bolts 68) and fixed. When assembling the circuit unit 10, the heat dissipation portion 82 of each heat dissipation busbar 80 is overlapped on a lower case 96 constituting a unit case 92 described later via an insulating heat-conductive sheet 84. The insulating heat conductive sheet 84 may be the same as the insulating heat conductive sheet 62 described above.

[0040] <Driving parts (fan motor 40)> A known fan motor may be used as the fan motor 40, and an internally provided blade portion (not shown) rotates around a central axis L to generate an airflow from one axial direction of the fan motor 40 to the other axial direction. In the first embodiment, an airflow is generated from the left to the right in the circuit unit 10. The airflow (airflow direction α) generated by the fan motor 40 in the circuit unit 10 is shown by a two-dot chain line in FIG. 2. As shown in FIG. 4, the central axis L of the fan motor 40 is located at the center of the front-rear direction of each heat sink 54 in a plan view. The fan motor of the electrical connection box 30 may be the same as the fan motor 40 of the circuit unit 10, and an airflow (airflow direction β) is generated from the right to the left in the electrical connection box 30.

[0041] In the first embodiment, the fan motor 40 is provided between the first heat generating component (relays 44) and the second heat generating component (fuse 46) in the circuit unit 10. That is, the relays 44 are provided on the right side of the fan motor 40, and the fuse 46 is provided on the left side of the fan motor 40. In short, in the first embodiment, the relays 44 and the heat sinks 54 fixed above the relays 44 are disposed downstream of the fan motor 40 in the air blowing direction α. ​​Also, the fuse 46 is disposed upstream of the fan motor 40 in the air blowing direction α.

[0042] Specifically, in the circuit unit 10, the space extending downstream from the fan motor 40 is an airflow path 86 in which airflow is generated as the blades of the fan motor 40 rotate. Meanwhile, in the circuit unit 10, the space upstream of the fan motor 40 is a suction path 88 (shown by a two-dot chain line in FIG. 5) in which airflow is generated in a direction in which air is sucked toward the fan motor 40 as the fan motor 40 blows air.

[0043] The above-mentioned air blowing path 86 and suction path 88 are areas surrounded by, for example, a unit case 92 (an upper case 94 and a lower case 96) described below. In the first embodiment, the air blowing path 86 is approximately the entire area surrounded by the unit case 92 downstream of the fan motor 40. Similarly, the suction path 88 is approximately the entire area surrounded by the unit case 92 upstream of the fan motor 40. As a result, in the circuit unit 10, the air blowing path 86 and the suction path 88 are formed with approximately the same cross-sectional area (cross-sectional area in a cross section perpendicular to the left-right direction (air blowing direction α)), and air flows with approximately a constant cross-sectional area.

[0044] The fan motor 40 is fixed to a support frame 90, for example by bolts, with a plurality of blades (not shown) housed in a case. The support frame 90 is then fixed to an upper case 94 of a unit case 92, which will be described later, for example by bolts, so that the fan motor 40 is fixed to the circuit configuration section 38 via the unit case 92.

[0045] <Unit Case 92> In the circuit unit 10, the circuit configuration section 38 including the heat generating components 14 (relays 44 and fuses 46), the fan motor 40, the heat sinks 54, etc. are housed in a unit case 92. The unit case 92 is a hollow rectangular parallelepiped as a whole, and includes an upper case 94 and a lower case 96 that can be assembled and disassembled relative to each other in the vertical direction. The upper case 94 and the lower case 96 are formed of, for example, a synthetic resin. An intake hole 98 is provided in the unit case 92 on the upstream side (left side) of the airflow direction α of the fan motor 40, and an exhaust hole 100 is provided on the downstream side (right side) of the airflow direction α of the fan motor 40.

[0046] <Upper Case 94> The upper case 94 is generally box-shaped and opens downward, and includes an upper bottom wall 102 and an upper peripheral wall 104 that protrudes downward from the outer periphery of the upper bottom wall 102. That is, the upper peripheral wall 104 includes an upper front wall 104a that constitutes the front wall, an upper rear wall 104b that constitutes the rear wall, an upper left wall 104c that constitutes the left wall, and an upper right wall 104d that constitutes the right wall. The upper case 94 is formed with a size such that the left-right dimension is larger than the front-to-rear dimension.

[0047] In the first embodiment, the above-mentioned intake hole and exhaust hole 98, 100 are both provided in the upper case 94. Furthermore, the suction path 88 in the unit case 92 communicates with the outside space through the intake hole 98, and the air blow path 86 in the unit case 92 communicates with the outside space through the exhaust hole 100.

[0048] Particularly in the first embodiment, the air intake hole 98 is configured to include a plurality of air intake slits 106. Each of the plurality of air intake slits 106 is formed in the left end portion of the upper bottom wall portion 102 and in the upper left wall portion 104c, penetrating each wall portion in the plate thickness direction. The air intake slits 106 are aligned in the front-rear direction in each of these wall portions.

[0049] Similarly, in the first embodiment, the exhaust hole 100 is configured to include a plurality of exhaust slits 108. The plurality of exhaust slits 108 are formed at the right end of the upper bottom wall portion 102 and the upper right wall portion 104d, penetrating each wall portion in the plate thickness direction. The exhaust slits 108 are aligned in the front-rear direction in each of these wall portions. The size of each of the exhaust slits 108 is not limited, but it is preferable that the opening width dimension A (see FIG. 5) of each of the exhaust slits 108 is, for example, 3 mm or more. Similarly, it is preferable that the opening width dimension of each of the intake slits 106 is, for example, 3 mm or more.

[0050] <Lower Case 96> The lower case 96 is generally box-shaped and opens upward, and includes a bottom wall 110 and a lower peripheral wall 112 that protrudes upward from the outer periphery of the bottom wall 110. The lower case 96 is formed with a size such that the left-right dimension is larger than the front-rear dimension. When the upper case 94 and the lower case 96 are assembled, the open end of the lower peripheral wall 112 and the open end of the upper peripheral wall 104 are butted against each other in the vertical direction, so that the upper opening of the lower peripheral wall 112 is covered by the upper case 94. The lower case 96 may hold, for example, a plurality of nuts (not shown) in a substantially embedded state.

[0051] The method of fixing the upper case 94 and lower case 96 having the above-mentioned shapes is not limited, but the upper case 94 and lower case 96 can be fixed, for example, by locking engagement using projections and recesses provided at corresponding positions on the upper peripheral wall portion 104 and the lower peripheral wall portion 112. Furthermore, the upper peripheral wall portion 104 and / or the lower peripheral wall portion 112 of the unit case 92 may have insertion holes formed in the thickness direction of each wall portion through which external electric wires (not shown) connected to the external connection portions 70, 72 and, if necessary, to the monitoring and control portion 74 are inserted.

[0052] <Electrical junction box 30> The structure of the electric junction box 30 is not limited, but the basic structure is the same as that of the circuit unit 10. That is, the electric junction box 30 includes a circuit configuration including heat-generating components and a fan motor for cooling the heat-generating components, and these circuit configuration and fan motor are housed in the junction box case 114. As described above, the airflow direction β by the fan motor of the electric junction box 30 is from right to left, and the junction box case 114 has an intake hole 116 on the upstream side (right side) of the airflow direction β and an exhaust hole 118 on the downstream side (left side) of the airflow direction β. The fan motor of the electric junction box 30 may be electrically connected to the microcomputer 42 as a drive unit of the circuit unit 10 as described above, or may be driven by a drive unit (e.g., a microcomputer) (not shown) provided inside the electric junction box 30, for example.

[0053] <Assembly of the circuit unit 10> The following describes a specific example of a method for assembling the circuit unit 10. Note that the method for assembling the circuit unit 10 is not limited to the embodiment described below.

[0054] First, the relays 44 and the fuses 46 are fixed to the lower case 96 with bolts together with the current-carrying bus bars 64b-64g and the heat-dissipating bus bars 80. The insulating heat-conducting sheets 84 are provided in advance on the upper surface of the bottom wall portion 110 of the lower case 96 and / or the lower surface of the heat-dissipating portion 82 of each heat-dissipating bus bar 80. The heat sinks 54 are overlapped with the portions 64a of the current-carrying bus bars 64d-64g that cover the relays 44 via the insulating heat-conducting sheets 62, and fixed with bolts or the like. The fan motor 40 is fixed to the upper case 94 via the support frame 90. Then, the monitoring and control unit 74 is housed in the lower case 96, and the monitoring and control unit 74 is electrically connected to the fan motor 40 and the current-carrying bus bars 64. Next, the upper case 94 is brought close to the lower case 96 from above and fixed to the upper case 94, thereby completing the circuit unit 10.

[0055] The circuit unit 10 manufactured in this manner is housed in a housing body 24 together with the electric junction box 30. Then, in the housing body 24 with the circuit unit 10 and the electric junction box 30 provided therein, a plurality of battery cells 18 and a BMS board 22 are housed and electrically connected, and an upper opening 26 in the housing body 24 is covered with a lid 28, thereby forming a battery pack 12.

[0056] In this battery pack 12, for example, when the temperature sensor 36 in the monitoring and control unit 74 detects that the temperature inside the circuit unit 10 exceeds a predetermined temperature, a fan drive signal is sent from the microcomputer 42 to the fan motor 40, the drive power of the fan motor 40 is turned ON, and the fan motor 40 is driven. Alternatively, when the current sensor 37 in the monitoring and control unit 74 detects that the magnitude of the current flowing through the circuit unit 10 exceeds a predetermined value, a fan drive signal is sent from the microcomputer 42 to the fan motor 40, the drive power of the fan motor 40 is turned ON, and the fan motor 40 is driven. Then, for example, when the temperature sensor 36 detects that the temperature inside the circuit unit 10 has become lower than the predetermined temperature, or when the current sensor 37 detects that the magnitude of the current flowing through the circuit unit 10 has become smaller than the predetermined value, or when a predetermined time has elapsed since the fan motor 40 was driven, a fan stop signal is sent from the microcomputer 42 to the fan motor 40, the drive power of the fan motor 40 is turned OFF, and the fan motor 40 is stopped.

[0057] In addition, when the fan motor of the electrical junction box 30 is electrically connected to the microcomputer 42, when it is detected that the temperature or current magnitude within the circuit unit 10 exceeds a predetermined value, a signal to drive the fan motor of the electrical junction box 30 is sent from the microcomputer 42, and the fan motor of the electrical junction box 30 can be driven together with the fan motor 40 of the circuit unit 10.

[0058] Here, for example, in the circuit unit 10, when the fan motor 40 is driven, air is sucked in through the intake hole 98, and an airflow in the blowing direction α is generated, causing the air to be exhausted through the exhaust hole 100. The air exhausted from the exhaust hole 100 has its direction changed by the inclined surface 34 of the exhaust direction restricting portion 32, and flows in a direction (forward) away from the battery cell 18. Then, the air whose direction has been changed by the inclined surface 34 flows inward in the left-right direction (leftward) between the circuit unit 10 and the front wall of the housing body 24, and reaches the left-right central portion of the housing body 24. The air that has reached the left-right central portion of the housing body 24 is sucked in again through the intake hole 98 and circulates.

[0059] The circuit configuration section 38 in the circuit unit 10 has the relays 44 and fuses 46, which are heat-generating components 14, and these components, which generate heat when energized, are cooled by the air blown by the fan motor 40. On the other hand, the temperature of the air passing through the circuit unit 10 increases when it comes into contact with the relays 44 and fuses 46, but the air with the increased temperature is redirected by the inclined surface 34 in the exhaust direction restricting section 32 and flows in a direction away from the battery cells 18. This prevents the air warmed by the heat-generating components 14 (relays 44 and fuses 46) from flowing toward the battery modules 16 (battery cells 18), which would adversely affect the battery modules 16. The air exhausted from the exhaust hole 100 can also be cooled by coming into contact with the wall of the housing body 24 in the battery pack 12, and the air exhausted from the exhaust hole 100 can be sucked in from the intake hole 98 at a lower temperature. This allows the heat generated in the heat-generating components 14 to be efficiently cooled.

[0060] In particular, in the first embodiment, the relays 44 that generate a relatively large amount of heat are arranged downstream of the fan motor 40 in the airflow direction α (airflow path 86), and the fuse 46 that generates a relatively small amount of heat is arranged upstream of the fan motor 40 in the airflow direction α (suction path 88). Therefore, the air temperature rise caused by the fuse 46 is suppressed to some extent upstream of the fan motor 40, and air at a relatively low temperature can be blown downstream of the fan motor 40 where the relays 44 that generate a relatively large amount of heat are arranged. This prevents relatively high-temperature air from being blown downstream of the fan motor 40, and allows stable heat dissipation from the relays 44 that generate a relatively large amount of heat. The above-mentioned effect can also be achieved in the electrical connection box 30.

[0061] The circuit unit 10 of the first embodiment having the above-mentioned structure includes a temperature sensor 36 and a current sensor 37 for monitoring the temperature and current value in the circuit unit 10, and a microcomputer 42 for driving the fan motor 40 when the detected values ​​exceed a predetermined value. This allows the conductive path from the microcomputer 42 to the fan motor 40 to be shortened, and the number of parts and the number of assembly steps can be reduced compared to, for example, a case in which an electric wire or the like is connected to the fan motor from outside the circuit unit. In addition, by shortening the conductive path from the microcomputer 42 to the fan motor 40, the fan motor 40 can be driven quickly, and for example, when the detected values ​​of the temperature sensor 36 and the current sensor 37 exceed a predetermined value, the fan motor 40 can be driven quickly to cool the heat-generating component 14 (each of the relays 44 and the fuse 46).

[0062] In particular, the fan motor 40 constitutes a driving component whose driving power is switched on / off according to the detected values ​​of the temperature sensor 36 and the current sensor 37. This allows a cooling mechanism for the heat-generating component 14 by the air blown by the fan motor 40 to be realized with a simple structure. For example, the driving power can be switched on when the detected values ​​of the temperature sensor 36 and the current sensor 37 exceed a predetermined value, and the driving power can be switched off when the detected values ​​of the temperature sensor 36 and the current sensor 37 become smaller than the predetermined value. The driving power can be quickly switched on / off by mounting the temperature sensor 36, the current sensor 37, and the microcomputer 42 on the same board 76. Furthermore, when the driving power is turned off after a predetermined time has elapsed after the fan motor 40 is driven, it is only necessary to monitor the temperature sensor 36 and the current sensor 37 to see if they exceed the predetermined value, and the monitoring and control unit 74 can be prevented from becoming overly sophisticated.

[0063] Moreover, the air blowing path 86 and the suction path 88 each have a substantially constant cross-sectional area in the air blowing direction α, and the cross-sectional areas of the paths 86, 88 are substantially equal to each other. As a result, air flows with a substantially constant cross-sectional area throughout substantially the entire circuit unit 10, thereby preventing localized temperature rises in areas where air is difficult to flow. Furthermore, the flowing air stably contacts the relays 44 in the air blowing path 86 and the fuses 46 in the suction path 88, improving heat dissipation efficiency.

[0064] <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.

[0065] (1) In the above embodiment, the exhaust direction regulating parts 32, 32 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 unit 10 and the electric connection box 30, but the present invention is not limited to this. For example, as in the circuit unit 120 shown in FIG. 8, the exhaust direction regulating part 122 may be formed integrally with the unit case 92 of the circuit unit 120 or the connection box case 114 of the electric connection box 30, or may be formed separately and fixed later. Note that the exhaust direction regulating part is not essential to the 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, the exhaust direction regulating part is not limited to the left and right side walls of the housing body, but may be provided on the bottom wall of the housing body or on the lid.

[0066] (2) In the above embodiment, the circuit unit 10 having a structure according to the present disclosure is provided on the right side inside the battery pack 12, but the electrical connection box 30 provided on the left side inside the battery pack 12 may also have a structure according to the present disclosure. Note that in the present disclosure, only the circuit unit may be provided inside the battery pack, and the electrical connection box is not essential. In other words, the circuit unit according to the present disclosure may have a length dimension that allows it to be accommodated on the right side inside the battery pack as in the above embodiment, or may have a length dimension that covers substantially the entire length of the battery pack in the left-right direction.

[0067] (3) In the above embodiment, the intake hole 98 and the exhaust hole 100 are respectively configured by a plurality of intake slits 106 and exhaust slits 108, but the present disclosure is not limited to this. The intake hole and the exhaust hole according to the present disclosure may be a single hole that penetrates the case in the thickness direction. Furthermore, the intake hole and the exhaust hole are not limited to being provided in the upper case that constitutes the unit case, but may be provided in the lower case, or may be provided in both the upper case and the lower case.

[0068] (4) In the above embodiment, the fan motor 40 is provided in the left-right middle portion of the circuit unit 10, the relays 44 as the first heat generating component are provided downstream of the fan motor 40 in the airflow direction α, and the fuse 46 as the second heat generating component is provided upstream of the fan motor 40 in the airflow direction α, but this is not limited to the above embodiment. For example, in the circuit unit according to the present disclosure, the fan motor as the driving component may be provided at the most upstream side of the airflow direction in the unit case (the left end in the above embodiment), and the heat generating component may be arranged downstream of the fan motor in the airflow direction and not arranged upstream of the airflow direction. Even in such a case, it is preferable that in the airflow path downstream of the fan motor in the airflow direction, a fuse or the like having a relatively small amount of heat generation is arranged upstream in the airflow path, and a relay having a relatively large amount of heat generation is arranged downstream in the airflow path.

[0069] (5) The driving component whose driving power is switched on / off based on the detected value of the temperature sensor or current sensor is not limited to a fan motor. In addition, the driving component is not limited to a component intended to cool a heat-generating component in a circuit unit.

[0070] (6) In the above embodiment, the monitoring and control unit 74 in the circuit unit 10 is provided with both the temperature sensor 36 and the current sensor 37 for monitoring the internal state of the circuit unit 10, but at least one of the temperature sensor and the current sensor may be provided. In the case where the driving power of the driving component (fan motor 40) is turned ON when the detection value of the temperature sensor exceeds a predetermined temperature, and the driving power of the driving component is turned OFF when the detection value of the temperature sensor is lower than the predetermined temperature, the temperature at which the driving power is turned ON and the temperature at which the driving power is turned OFF may be different from each other, and for example, the temperature at which the driving power is turned OFF may be lower than the temperature at which the driving power is turned ON. In addition, in the case where both the temperature sensor and the current sensor are provided, for example, the driving power of the driving component may be turned ON when the detection values ​​of both the temperature sensor and the current sensor exceed a predetermined value, or the driving power of the driving component may be turned OFF when the detection values ​​of both the temperature sensor and the current sensor are lower than the predetermined value. [Explanation of symbols]

[0071] 10 Circuit unit (embodiment 1) 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 Electrical junction box 32 Exhaust direction control part 34 Slope 36 Temperature Sensor 37 Current Sensor 38 Circuit component 40 Fan motor (driving part) 42 Microcomputer (drive unit) 44 Relay (first heat generating component) 46 Fuse (second heat generating component) 48 Case body 50 Terminal section 52 Insulating partition plate 54 Heat sink 56 Plate-shaped part 58 Heat sink 60 Gap 62 Insulating heat conductive sheet 64 Current carrying busbar 64a The portion of the current-carrying busbar that covers the upper part of the relay 64b~64g Current-carrying busbars 66 Terminal section 68 Volts 70,72 External connection part 74 Monitoring and control section 76 Substrate 78 Circuit Board Case 80 Heat dissipation bus bar 82 Heat radiation part 84 Insulating heat conductive sheet 86 Air flow path 88 Suction Path 90 Support Frame 92 Unit Case 94 Upper Case 96 Lower case 98 Air Intake Hole 100 Exhaust Vent 102 Upper bottom wall 104 Upper peripheral wall 104a Upper front wall 104b Upper rear wall 104c Upper left wall 104d Upper right wall 106 Intake slit 108 Exhaust slit 110 Bottom wall 112 Lower peripheral wall 114 Junction box case 116 Air Intake Hole 118 Exhaust Vent 120 Circuit unit (another embodiment) 122 Exhaust direction control part L center axis α,β Air blowing direction

Claims

1. A circuit unit accommodated in a housing of a battery pack, a circuit configuration unit including at least one of a temperature sensor and a current sensor; A driving component driven by power from the circuit configuration unit; Equipped with the circuit configuration unit has a drive unit that switches ON / OFF of drive power for the drive component, the driving unit switches ON / OFF of driving power for the driving component in response to a detection value of at least one of the temperature sensor and the current sensor. Circuit unit.

2. 2. The circuit unit according to claim 1, wherein the circuit configuration includes a heat-generating component, and the driving component is a fan motor that promotes cooling of the heat-generating component.

3. the heat generating component includes a first heat generating component thermally connected to a heat sink; The circuit unit according to claim 2 , wherein the first heat generating component and the heat sink are disposed downstream of the fan motor in a direction of airflow from the fan motor.

4. 4. The circuit unit according to claim 3, wherein the heat generating components include a second heat generating component arranged upstream of the fan motor in the air blowing direction, and the amount of heat generated by the second heat generating component is smaller than the amount of heat generated by the first heat generating component.

5. a suction path extending from an upstream side of the fan motor toward the fan motor in a blowing direction of the fan motor, and a blowing path extending from the fan motor toward a downstream side, The circuit unit according to claim 2 , wherein a cross-sectional area in a direction perpendicular to the air blowing direction is constant in an entire region from the suction path to the air blowing path.

6. 5. The circuit unit according to claim 1, wherein the driving unit turns on the driving power of the driving component when the detection value of the temperature sensor exceeds a predetermined temperature, and turns off the driving power of the driving component when the detection value of the temperature sensor falls below the predetermined temperature or when a predetermined time has elapsed since the driving component was driven.

7. The circuit unit according to any one of claims 1 to 4, wherein the driving unit turns on the driving power of the driving component when the detection value of the current sensor exceeds a predetermined value, and turns off the driving power of the driving component when the detection value of the current sensor becomes smaller than the predetermined value or when a predetermined time has elapsed since the driving component was driven.

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