Circuit unit

Abstract

To provide a circuit unit that can achieve high heat-dissipation performance even when stored in an enclosure of a battery pack.SOLUTION: A circuit unit 10 is to be stored in an enclosure 20 of a battery pack 12. The circuit unit includes a circuit configuration part 36 comprising a heating part 14, a fan motor 38, a bus bar 40 made from a metal plate in thermal contact with the heating part 14. The bus bar 40 has a corrugated plate part 68 formed by deforming the metal plate into a corrugated plate shape. The corrugated plate part 68 of the bus bar 40 is arranged on a downstream side of a blowing direction α of the fan motor 38 in a manner that peaks 72 and valleys 74 of the corrugated plate part 68 extend along the blowing direction α.SELECTED DRAWING: Figure 4

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 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 cases, high-voltage and high-current power is supplied to the circuit unit, which may cause the heat-generating component to generate excessive heat, and therefore further improvement in heat dissipation has been demanded.

[0005] Therefore, a circuit unit capable of improving heat dissipation even when housed inside a battery pack housing is disclosed. [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 component including a heat-generating component, a fan motor, and a bus bar made of a flat metal plate in thermal contact with the heat-generating component, wherein the bus bar has a corrugated portion in which the flat metal plate is deformed into a corrugated shape, and the corrugated portion of the bus bar is positioned downstream of the air blowing direction of the fan motor so that peaks and valleys of the corrugated portion extend along the air blowing direction. Effect of the Invention

[0007] According to the circuit unit of the present disclosure, even when it is housed inside the housing of a battery pack, it is possible to improve heat dissipation properties. [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. [Figure 4] FIG. 4 is a perspective view showing the circuit unit shown in FIG. 3 with an upper case that constitutes a case removed. [Diagram 5] FIG. 5 is a plan view showing the circuit unit shown in FIG. 3 with an upper case that constitutes a case removed. [Figure 6] 6 is a vertical cross-sectional view of the circuit unit shown in FIG. 3, and is an enlarged view of the cross section taken along line VI-VI in FIG. [Figure 7] 7 is a vertical cross-sectional view of the circuit unit shown in FIG. 3, and is an enlarged view of the VII-VII cross section in FIG. [Figure 8] FIG. 8 is an enlarged exploded perspective view showing a main part of the circuit unit shown in FIG. 3 in an exploded state. [Figure 9] FIG. 9 is a perspective view showing a state in which an upper case constituting a case in the circuit unit according to the second embodiment is removed. [Figure 10] FIG. 10 is a plan view showing the circuit unit shown in FIG. 9 with an upper case that constitutes a case removed. [Figure 11] FIG. 11 is an exploded perspective view of the circuit unit shown in FIG. [Figure 12] FIG. 12 is an exploded perspective view showing the circuit unit shown in FIG. 9 from the rear side. [Figure 13] FIG. 13 is a perspective view showing a circuit unit according to another embodiment of the present disclosure, the upper diagram showing the hinge opening / closing part in an open state and the lower diagram showing the hinge opening / closing part in a closed state. [Figure 14] FIG. 14 is a plan view showing a circuit unit according to still 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 circuit unit of the present disclosure includes: (1) A circuit unit housed within a battery pack housing, comprising: a circuit component including a heat-generating component; a fan motor; and a bus bar made of a flat metal plate in thermal contact with the heat-generating component, wherein the bus bar has a corrugated portion in which the flat metal plate is deformed into a corrugated shape, and the corrugated portion of the bus bar is positioned downstream of the air blowing direction of the fan motor so that peaks and valleys of the corrugated portion extend along the air blowing direction.

[0010] According to this aspect, the busbar in thermal contact with the heat-generating component has a corrugated portion, which makes it possible to ensure a large heat dissipation area. Moreover, the corrugated portion of the busbar is arranged downstream in the airflow direction of the fan motor so that the peaks and valleys of the corrugated portion extend along the airflow direction of the fan motor. This allows the airflow from the fan motor to pass quickly along the peaks and valleys of the corrugated portion, so that the corrugated portion can be efficiently cooled by the airflow from the fan motor. As a result, compared to a conventional structure in which the heat-generating component and the flat busbar are cooled only by the airflow from the fan motor, it is possible to advantageously promote heat dissipation from the heat-generating component, and it is possible to improve the heat dissipation of the circuit unit even when it is housed in the housing of a battery pack.

[0011] In this embodiment, it is sufficient that at least the corrugated portion of the busbar that is in thermal contact with the heat-generating component is positioned downstream in the air blowing direction of the fan motor; however, by positioning the heat-generating component and the entire busbar downstream in the air blowing direction of the fan motor so that they are cooled by the air blown by the fan motor, further improvement in heat dissipation can be achieved.

[0012] (2) In the above (1), it is preferable that the busbar has a flat connection portion fastened to a terminal portion of the heat-generating component, and the busbar is in thermal contact with the heat-generating component via the connection portion. Since the busbar has a connection portion fastened to the terminal portion of the heat-generating component in addition to the corrugated plate portion, heat from the heat-generating component is directly transferred to the busbar, and heat dissipation from the corrugated plate portion can be advantageously promoted. In particular, since the connection portion is flat, heat from the heat-generating component is efficiently transferred from the terminal portion to the connection portion.

[0013] The bus bar may be a current-carrying bus bar having a connection portion to another member, or a heat-dissipating bus bar that is not connected to another member.

[0014] (3) In the above (1) or (2), it is preferable that the heat-generating component and the bus bar are disposed downstream of the fan motor in the air blowing direction. By disposing the heat-generating component and the entire bus bar downstream of the fan motor in the air blowing direction and cooling them by the air blown by the fan motor, it is possible to further improve heat dissipation.

[0015] <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.

[0016] <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 8. The circuit unit 10 is mounted 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 component 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. 6), 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. 6), 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.

[0017] <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.

[0018] 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.

[0019] 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.

[0020] In the first embodiment, in the battery pack 12, an electric connection box 30 is provided to the right 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.

[0021] <Circuit unit 10> The circuit unit 10 includes a circuit configuration section 36 including the heat-generating component 14, a fan motor 38, and a bus bar made of a metal plate in thermal contact with the heat-generating component 14. In the first embodiment, the bus bar in thermal contact with the heat-generating component 14 includes a current-carrying bus bar 40 that forms a conductive path, and a heat-dissipating bus bar 42 that forms a heat-dissipating path.

[0022] In the first embodiment, the circuit unit 10 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), and the electrical junction box 30 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). The circuit unit 10 is provided on the left side of the battery pack 12, and the electrical junction box 30 is provided on the right 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.

[0023] <Heat generating component 14 (relay 44 and fuse 46)> In the first embodiment, the heat generating component 14 includes a relay 44, which is a first heat generating component, and a fuse 46, which is a second heat generating component. In particular, in the first embodiment, as shown in FIG. 7 and the like, a pair of relays 44, 44 are stacked on top of each other at a distance from each other in the up-down direction in the left part of the circuit unit 10. Each relay 44 has a case body 48 that is a substantially hollow rectangular box, and a pair of terminals 50, 50 are exposed from the case body 48 at the front side (respective forward side) of each relay 44 at a distance from each other in the left-right direction. In addition, an insulating partition plate 52 that separates each terminal 50 is provided around each terminal 50 on the surface of the case body 48, specifically between each terminal 50 in the left-right direction. In addition, a coil 54 shown by a two-dot chain line in FIGS. 5 and 7 is accommodated in the case body 48 of each relay 44.

[0024] In the first embodiment, the fuse 46, which is a second heat generating component, is provided on the front side of the right portion of the circuit unit 10. 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 components (relays 44). Furthermore, a pre-charge relay 56 and a pre-charge resistor 58 are provided on the rear side of the right portion of the circuit unit 10.

[0025] <Circuit configuration section 36> The relays 44 and fuses 46 are electrically connected by a plurality of current-carrying bus bars 40. That is, the current-carrying bus bars 40 are overlapped with a pair of terminal portions 60, 60 of the fuse 46 and with each terminal portion 50 of each relay 44, and are fixed by bolts 62.

[0026] <Electric bus bars 40a to 40e> Specifically, energizing busbars 40a, 40b are fixed to each terminal portion 60 of fuse 46 by bolts 62. As shown in Fig. 8, energizing busbar 40c is fixed to the right terminal portion 50 of the lower relay 44 by bolts 62, and energizing busbar 40d is fixed to the right terminal portion 50 of the upper relay 44 by bolts 62. Furthermore, energizing busbar 40e is fixed to each left terminal portion 50 of the upper and lower relays 44 by bolts 62. Then, energizing busbar 40b and energizing busbar 40c are electrically connected to each other.

[0027] As a result, an external connection portion 64 is formed by the end of the energizing busbar 40a at the right end of the circuit unit 10, and external connection portions 66, 66 are formed by the ends of the energizing busbars 40d, 40e at the left 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 64, 66 and fixed with bolts or the like, so that each of the energizing busbars 40a to 40e 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 64 is connected to the battery module 16 (particularly the busbar module) to serve as a connection portion for inputting electric power to the circuit unit 10, and each of the external connection portions 66 is connected to an external electric device to serve as a connection portion for outputting electric power to the external electric device. The pre-charge relay 56 and the pre-charge resistor 58 are appropriately connected to, for example, any of the energizing busbars 40a to 40e via electric wires or the like (not shown).

[0028] In the first embodiment, the circuit configuration section 36 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 pre-charge relay 56, the pre-charge resistor 58, and the current-carrying bus bars 40a to 40e.

[0029] <Corrugated sheet section 68> The busbar has a corrugated plate portion 68 formed by deforming a flat metal plate into a corrugated shape, and in the first embodiment, the corrugated plate portion 68 is provided on the current-carrying busbar 40. In particular, in the first embodiment, of the current-carrying busbars 40a-40e, the current-carrying busbars 40c-40e connected to the relays 44 are provided with the corrugated plate portion 68 on a part thereof.

[0030] Specifically, for example, both longitudinal (left-right) ends of the current-carrying busbar 40c are fixed by bolts 62, and these longitudinal ends are flat and spread out so that the fastening force of the bolts 62 can be stably applied. In particular, a flat connection portion 70 is provided at the left end of the current-carrying busbar 40c, which is fastened to the right terminal portion 50 of the relay 44 below. A corrugated plate portion 68 is provided at the longitudinal (left-right) intermediate portion of the current-carrying busbar 40c. That is, the current-carrying busbar 40c is in thermal contact with the relay 44 via the connection portion 70.

[0031] Further, the current-carrying busbar 40d has a corrugated plate portion 68 at its right end, and a portion to the left of the corrugated plate portion 68 is bent and extends out in a predetermined shape. A flat-plate-shaped connection portion 70 is provided at a portion of the current-carrying busbar 40d adjacent to the left of the corrugated plate portion 68, and one of the external connection portions 66 is formed at the left end of the current-carrying busbar 40d. Further, the current-carrying busbar 40e has a corrugated plate portion 68 at its left-right middle portion, and a flat-plate-shaped connection portion 70 is provided at its right end, and is provided at its right end, and is fastened to each of the left terminal portions 50 of the upper and lower relays 44. The other of the external connection portions 66 is formed at the left end of the current-carrying busbar 40e. That is, the current-carrying busbars 40d, 40e are also in thermal contact with each of the relays 44 via the connection portions 70.

[0032] More specifically, the corrugated plate portion 68 has a shape in which peaks 72 that convex in one direction in the plate thickness direction and valleys 74 that convex in the other direction in the plate thickness direction are alternately repeated and are continuous, and these peaks 72 and valleys 74 are connected by a smoothly curved surface. These peaks 72 and valleys 74 are arranged so as to extend in the left-right direction along the air blowing direction α of the fan motor 38 described later.

[0033] In the first embodiment, the connection portion 70 of each of the current-carrying busbars 40c to 40e is provided with a heat dissipation portion 76 that protrudes forward. The current-carrying busbar 40c has a heat dissipation portion 76 at the upper end of the connection portion 70, and the current-carrying busbar 40d has a heat dissipation portion 76 at the lower end of the connection portion 70, and these heat dissipation portions 76, 76 face each other at a distance in the vertical direction. Furthermore, the current-carrying busbar 40e has a heat dissipation portion 76 at both upper and lower ends of the connection portion 70, and these heat dissipation portions 76, 76 face each other at a distance in the vertical direction. Each of these four heat dissipation portions 76 extends in the horizontal direction (a direction perpendicular to the vertical direction) so as to be approximately parallel to the air blowing direction α of the fan motor 38 described later. This prevents the air blown by the fan motor 38 from being hindered by the heat dissipation portions 76, and heat dissipation from each heat dissipation portion 76 can be realized by the air blown by the fan motor 38.

[0034] <Heat dissipation busbar 42> Further, in the first embodiment, a plurality of heat dissipation busbars 42 are fixed at the fixing points between the terminals 60 of the fuse 46 and the current-carrying busbars 40a, 40b, the connection points between the current-carrying busbars 40b, 40c, etc. Each heat dissipation busbar 42 is substantially L-shaped and has a heat dissipation portion 78 that spreads in the horizontal direction and a portion that protrudes upward from each heat dissipation portion 78. The upward protruding portion of each heat dissipation busbar 42 is overlapped with each terminal 60 of the fuse 46 together with each current-carrying busbar 40a, 40b, or overlapped with each current-carrying busbar 40b, 40c, and is fastened together and fixed by a bolt 62. Also, as shown in FIG. 6, when assembling the circuit unit 10, the heat dissipation portion 78 of each heat dissipation busbar 42 is overlapped with a lower case 88 constituting a case 84 described later via an insulating heat-conductive sheet 80. The insulating heat conductive sheet 80 may be, for example, a known one.

[0035] <Fan motor 38> A known fan motor may be used as the fan motor 38, and an internally provided blade portion (not shown) rotates about a central axis L to generate an airflow from one axial direction of the fan motor 38 to the other. In the first embodiment, an airflow is generated from the right to the left in the circuit unit 10. The airflow (airflow direction α) generated by the fan motor 38 in the circuit unit 10 is shown by a two-dot chain line in Figures 2 and 5. In the first embodiment, the fan motor 38 is provided at the right end of the circuit unit 10.

[0036] This fan motor 38, with a plurality of blades (not shown) housed in a case, is fixed to a support frame 82, for example by bolts. This support frame 82 is then fixed to a lower case 88 of a case 84, which will be described later, by bolts, for example, so that the fan motor 38 is fixed to the circuit configuration unit 36 ​​via the case 84.

[0037] <Case 84> In the circuit unit 10, the circuit configuration section 36 including the heat-generating components 14 (relays 44 and fuses 46), the fan motor 38, etc. are housed in a case 84. The case 84 is a hollow rectangular parallelepiped as a whole, and includes an upper case 86 and a lower case 88 that can be assembled and disassembled relative to each other in the vertical direction. The upper case 86 and the lower case 88 are formed of, for example, a synthetic resin. An intake hole 90 is provided in the case 84 on the upstream side (right side) of the airflow direction α of the fan motor 38, and an exhaust hole 92 is provided on the downstream side (left side) of the airflow direction α of the fan motor 38.

[0038] <Upper Case 86> The upper case 86 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 upper case 86 is formed with a size in which the left-right dimension is larger than the front-rear dimension. Note that the left part of the upper case 86 has a larger vertical dimension than the right part, so that the relays 44 and the like that are arranged side by side in the vertical direction are stably accommodated in the upper case 86. In the first embodiment, the above-mentioned intake holes and exhaust holes 90, 92 are both provided in the upper case 86.

[0039] Particularly, in the first embodiment, the intake hole 90 is configured to include a plurality of intake slits 98. The plurality of intake slits 98 are formed in the right ends of the upper bottom wall portion 94, the upper front wall portion 96a, and the upper rear wall portion 96b, and in the upper right wall portion 96d, penetrating each wall portion in the plate thickness direction. The intake slits 98 are aligned in the front-rear direction and / or the left-right direction in each of these walls.

[0040] Similarly, in the first embodiment, the exhaust hole 92 is configured to include a plurality of exhaust slits 100. The plurality of exhaust slits 100 are formed at the left ends of the upper bottom wall portion 94, the upper front wall portion 96a, and the upper rear wall portion 96b, and at the upper left wall portion 96c, penetrating each wall portion in the plate thickness direction. The exhaust slits 100 are aligned in the front-rear direction and / or the left-right direction in each of these walls. The size of each of the exhaust slits 100 is not limited, but it is preferable that the opening width dimension A (see FIG. 7) of each exhaust slit 100 is, for example, 3 mm or more. Similarly, it is preferable that the opening width dimension of each intake slit 98 is, for example, 3 mm or more.

[0041] <Lower Case 88> The lower case 88 is generally box-shaped and opens upward, and includes a bottom wall 102 and a lower peripheral wall 104 that protrudes upward from the outer periphery of the bottom wall 102. The lower case 88 is formed with a size in which the left-right dimension is larger than the front-rear dimension. When the upper case 86 and the lower case 88 are assembled, the open end of the lower peripheral wall 104 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 104 is covered by the upper case 86. As shown in FIG. 6, the lower case 88 holds a plurality of nuts 106 in a substantially embedded state, and each nut 106 is fastened by the aforementioned bolt 62, or a bolt (not shown) that is inserted through the support frame 82 that supports the fan motor 38 and each external connection portion 64, 66.

[0042] Although the method of fixing the upper case 86 and the lower case 88 having the above-mentioned shapes is not limited, the upper case 86 and the lower case 88 can be fixed, for example, by a recessed and projecting engagement between a lock recess 108 provided in the upper peripheral wall portion 96 and a lock protrusion 110 provided in the lower peripheral wall portion 104. Furthermore, the upper peripheral wall portion 96 and / or the lower peripheral wall portion 104 of the case 84 have insertion holes 112 formed therein that penetrate each wall portion in the thickness direction, through which external electric wires (not shown) connected to the external connection portions 64, 66 are inserted.

[0043] <Partition 114> Here, the internal space of the case 84 is divided into front and rear sides by a partition plate 114. The partition plate 114 is a plate-shaped member extending in the left-right direction as a whole, and is made of metal or synthetic resin. This partition plate 114 is attached from above the circuit configuration unit 36, and is provided across the current-carrying bus bar 40a and each of the heat-dissipating bus bars 42. The partition plate 114 can be fixed to the lower case 88 constituting the case 84, for example, by a bolt (not shown) or the like. By providing such a partition plate 114 inside the case 84, the pre-charge relay 56, the pre-charge resistor 58, etc. are located in an area rearward of the partition plate 114, and each of the relays 44, the fuses 46, etc. are located in an area forward of the partition plate 114. Although the partition plate 114 generally extends in the left-right direction, it has a portion on the left side that is bent in the front-rear direction like a crank, and a gap 116 of a predetermined size is formed between the partition plate 114 and each relay 44. In the internal space of the case 84 that is partitioned in the front-rear direction by the partition plate 114, the fan motor 38 described above is disposed in the front region.

[0044] Here, in the circuit unit 10, the space extending from the fan motor 38 toward the downstream side is the airflow path 118 (shown by the two-dot chain line in FIGS. 6 and 7) which is the path of the airflow generated with the rotation of the blades of the fan motor 38. In the first embodiment, since the partition plate 114 is provided inside the case 84 as described above, the airflow path 118 is configured in the area in front of the partition plate 114. In short, the air blown by the fan motor 38 is applied to the area in front of the partition plate 114 (airflow path 118) as shown by the two-dot chain line in FIG. 5.

[0045] That is, in the first embodiment, an airflow path 118 extending from the fan motor 38 toward the downstream side in the airflow direction α of the fan motor 38 is formed by a space in front of the partition plate 114, and the relays 44 as the first heat-generating components and the fuse 46 as the second heat-generating components are arranged in this airflow path 118. In particular, in the first embodiment, the relays 44 as the first heat-generating components, the fuses 46 as the second heat-generating components, and the current-carrying bus bars 40a to 40e connecting them are all arranged downstream (left) of the fan motor 38 in the airflow direction α, and are not arranged upstream (right). As a result, the corrugated plate portions 68 of the current-carrying bus bars 40c to 40e are arranged downstream of the fan motor 38 in the airflow direction α such that the peak portions 72 and the valley portions 74 of each corrugated plate portion 68 extend along the airflow direction α.

[0046] Such an airflow path is, for example, an area surrounded by a case, but in the first embodiment, because the partition plate 114 is provided inside the case 84, the airflow path 118 in the first embodiment is configured to include, in addition to the case 84, the partition plate 114 that is disposed inside the case 84 and divides the internal space of the case 84. In the airflow path 118, the fuse 46 that generates a relatively small amount of heat is disposed on the upstream side, and the relays 44 that generate a relatively large amount of heat are disposed on the downstream side.

[0047] More specifically, airflow path 118 is a space through which airflow generated by driving fan motor 38 can pass in the left-right direction within case 84. In particular, in the first embodiment, in a region of airflow path 118 from fan motor 38 to each relay 44, the cross-sectional area of ​​airflow path 118 in a direction perpendicular to airflow direction α (direction perpendicular to the left-right direction) is substantially constant, and the cross-sectional area of ​​airflow path 118 is increased in a portion where partition plate 114 is bent in a crank shape.

[0048] Here, the air flowing downstream (leftward) from the fan motor 38 comes into contact with each relay 44 and each current-carrying busbar 40c, 40d connected to the right of each relay 44, so that the direction of flow of the air is changed in part, and a part of the air flows into the gap 116 between the partition plate 114 and each relay 44. Then, the air flowing into this gap 116 flows between each relay 44 and the partition plate 114 so as to follow the surface of the case body 48 of each relay 44 in which the coil 54 is housed. Therefore, in the first embodiment, the air blowing path 118 is configured to include a body cooling path 120 that blows air to the surface of the case body 48 of each relay 44. As a result, not only the current-carrying busbars 40c to 40e that are thermally connected to the terminal portion 50 of each relay 44 but also the case body 48 of each relay 44 can be cooled by the air blown by the fan motor 38.

[0049] Note that the crank-shaped bent portion of the partition plate 114 (i.e., the main body cooling path 120) is not essential, and the airflow path 118 may extend substantially straight in the left-right direction. In this case, for example, the case main body 48 of each relay 44 may be located rearward of the partition plate 114, and the current-carrying bus bars 44c-44e (particularly the corrugated plate portions 68) connected to the terminal portions 50 of each relay 44 may be located in the airflow path 118 forward of the partition plate 114. Even with this configuration, the air blown from the fan motor 38 acts on the corrugated plate portions 68 of the current-carrying bus bars 44c-44e, thereby providing a good heat dissipation effect.

[0050] <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 122 for cooling the heat-generating components, and these circuit configuration and fan motor 122 are housed in a junction box case 124. The airflow direction β (shown by a two-dot chain line in FIG. 2) by the fan motor 122 of the electric junction box 30 is a direction from left to right, and an air intake hole 126 is provided on the upstream side (left side) of the airflow direction β in the junction box case 124, and an exhaust hole 128 is provided on the downstream side (right side) of the airflow direction β. In addition, a monitoring and driving unit 130 is provided inside the electric junction box 30, which monitors, for example, the temperature inside the electric junction box 30 and drives the fan motor 122 inside the electric junction box 30 when the temperature inside the electric junction box 30 exceeds a predetermined temperature. The monitoring and driving unit 130 may be electrically connected to the fan motor 38 in the circuit unit 10 via an electric wire or the like (not shown), and the fan motor 38 of the circuit unit 10 may be driven together with the fan motor 122 of the electrical connection box 30.

[0051] In addition, the driving unit that drives the fan motor 38 of the circuit unit 10 may be provided separately from the above-mentioned monitoring and driving unit 130, and may be provided, for example, within the circuit unit 10, or the above-mentioned BMS board 22 and fan motor 38 may be electrically connected so that the fan motor 38 of the circuit unit 10 is driven when the BMS board 22 detects that the temperature, current magnitude, etc. within the battery pack 12 exceed a predetermined value.

[0052] <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.

[0053] First, the relays 44, the fuses 46, the pre-charge relays 56, and the pre-charge resistors 58 are fixed to the lower case 88 with bolts together with the current-carrying bus bars 40a to 40e and the heat-dissipating bus bars 42. The insulating heat-conducting sheets 80 are provided in advance on the upper surface of the bottom wall portion 102 of the lower case 88 and / or the lower surface of the heat-dissipating portion 78 of each heat-dissipating bus bar 42. The fan motor 38 is fixed to the lower case 88 via the support frame 82. Thereafter, a partition plate 114 is disposed from above so as to straddle the current-carrying bus bar 40a and the heat-dissipating portion 78 of each heat-dissipating bus bar 42, and is fixed to the lower case 88 with bolts (not shown). Next, the upper case 86 is brought close to the lower case 88 from above, and the upper case 86 and the lower case 88 are fixed to each other by fitting the lock recesses 108 and the lock protrusions 110 together, thereby completing the circuit unit 10. The fan motor 38 and the monitoring and driving unit 130 in the electrical junction box 30 can be electrically connected at any time.

[0054] 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.

[0055] Here, in the circuit unit 10, when the monitoring and driving unit 130 detects that the temperature in the electrical junction box 30 has exceeded a predetermined temperature, the fan motor 38 is driven to draw air in through the air intake 90, and an airflow in the airflow direction α is generated, causing the air to be exhausted through the exhaust hole 92. The air exhausted from the exhaust hole 92 has its direction changed by the inclined surface 34 in the exhaust direction restricting unit 32, and flows in a direction (forward) away from the battery cell 18. The air that has been changed in direction by the inclined surface 34 flows inward in the left-right direction (to the right) 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 again drawn in through the air intake 90 and circulated.

[0056] The circuit configuration section 36 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 38. 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) and adversely affecting the battery modules 16. The air exhausted from the exhaust hole 92 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 92 can be sucked in from the intake hole 90 at a lower temperature. This allows the heat generated in the heat-generating components 14 to be efficiently cooled. The above effect can also be achieved in the electrical connection box 30.

[0057] Furthermore, in the first embodiment, the relays 44 that generate a relatively large amount of heat are disposed downstream of the airflow direction α in the airflow path 118, and the fuses 46 that generate a relatively small amount of heat are disposed upstream of the airflow direction α. ​​Therefore, the air temperature rise caused by the fuses 46 upstream of the fan motor 38 is suppressed to some extent, and relatively low-temperature air can be blown downstream of the fan motor 38 where the relays 44 that generate a relatively large amount of heat are disposed. This prevents relatively high-temperature air from being blown downstream of the fan motor 38, and allows stable heat dissipation from the relays 44 that generate a relatively large amount of heat.

[0058] In particular, in the first embodiment, the relays 44 and fuses 46, which are the heat-generating components 14, are arranged downstream of the fan motor 38 in the airflow direction α, and are not arranged upstream of the fan motor 38 in the airflow direction α. ​​This prevents the air whose temperature has increased due to the heat generated by the heat-generating components 14 from affecting the fan motor 38. In addition, the air whose temperature has increased by passing through the heat-generating components 14 is cooled by coming into contact with the housing main body 24 while being discharged from the exhaust hole 92 and circulating to the intake hole 90, so that it is possible to stably prevent the high-temperature air from affecting the fan motor 38 and adversely affecting the operation of the fan motor 38.

[0059] According to the circuit unit 10 of the first embodiment having the above-mentioned structure, among the current-carrying bus bars 40a-40e, in particular, the current-carrying bus bars 40c-40e that are in thermal contact with the terminal portions 50 of the relays 44 (fastened by the bolts 62 in the first embodiment) have the corrugated plate portions 68, and the surface area of ​​the current-carrying bus bars 40c-40e is increased in each of the corrugated plate portions 68. As a result, when air is blown by the fan motor 38, heat generated in each of the relays 44 can be effectively dissipated in each of the corrugated plate portions 68. In particular, since each of the peak portions 72 and each of the valley portions 74 that constitute the corrugated plate portion 68 extend in the same direction as the air blowing direction α of the fan motor 38, the formation of the corrugated plate portion 68 can prevent the air blown from the fan motor 38 from being obstructed.

[0060] Each of the current-carrying busbars 40c-40e having the corrugated plate portion 68 has a flat-plate-shaped connection portion 70 fastened to the terminal portion 50 of each relay 44, and each of the current-carrying busbars 40c-40e is in thermal contact with each relay 44 via each connection portion 70. Since the connection portion 70 of each of the current-carrying busbars 40c-40e is flat, the fastening force of each bolt 62 can be stably applied to each of the current-carrying busbars 40c-40, and each of the current-carrying busbars 40c-40e can be more firmly fixed to each of the relays 44. Furthermore, since each of the connection portions 70 is flat, a relatively large contact area with each of the terminal portions 50 can be secured, and heat generated in each of the relays 44 can be efficiently transferred to each of the current-carrying busbars 40c-40e. This further improves the heat dissipation efficiency.

[0061] In particular, in the first embodiment, the relays 44 and the current-carrying busbars 40c-40e connected to the relays 44 and having the corrugated sheet portions 68 are disposed downstream in the air blowing direction α of the fan motor 38. This allows heat dissipation from the surfaces of the relays 44 located on the air blowing path 118 (including the main body cooling path 120 in the first embodiment) and from portions of the current-carrying busbars 40c-40e other than the corrugated sheet portions 68, thereby further improving the heat dissipation efficiency.

[0062] <Embodiment 2> Hereinafter, a circuit unit 140 according to a second embodiment of the present disclosure will be described with reference to Figs. 9 to 12. The basic configuration of the circuit unit 140 is the same as that of the circuit unit 10 according to the first embodiment, but the circuit unit 140 according to the second embodiment has a corrugated plate portion 68 not only in the current-carrying bus bar 142 but also in the heat-dissipating bus bar 144. In addition, since the circuit unit 140 according to the second embodiment can be housed in the housing 20 of the battery pack 12 together with the electric connection box 30 as in the first embodiment, the following description will omit a description of parts other than the circuit unit 140. In the following description, the same reference numerals as those in the first embodiment are used in the drawings to denote the substantially same members and parts as those in the first embodiment, and detailed description thereof will be omitted.

[0063] The circuit unit 140 includes a circuit configuration section 146 including the relays 44 and fuses 46, which are heat-generating components 14, a fan motor 148, and a case 150 (an upper case 152 and a lower case 154) that houses the circuit configuration section 146 and the fan motor 148. The case 150 is provided with an intake hole 90 provided upstream of the fan motor 148 in the airflow direction γ (see FIG. 10), and an exhaust hole 92 provided downstream of the airflow direction γ.

[0064] In the second embodiment, a pair of relays 44, 44 are arranged at a distance from each other in the left-right direction on the left side of the circuit unit 140, and a fuse 46, a pre-charge relay 56, and a pre-charge resistor 58 are arranged on the right side of the circuit unit 140. These heat generating components 14 are electrically connected by a plurality of current-carrying bus bars 142a to 142f. Therefore, in the second embodiment, the circuit configuration unit 146 is configured including the relays 44, the fuse 46, the pre-charge relay 56, the pre-charge resistor 58, and the current-carrying bus bars 142a to 142f. The heat dissipation bus bars 144a to 144h are thermally connected to the current-carrying bus bars 142a to 142f, and in particular, the heat dissipation bus bars 144e to 144h are fastened together with the current-carrying bus bars 142c to 142f to the terminal portions 50 of the relays 44 by the bolts 62.

[0065] The fan motor 148 is disposed in the center of the circuit unit 140 in the left-right direction. The fan motor 148 generates an airflow from right to left by rotating a blade portion (not shown) provided inside the fan motor 148 around a central axis M. The airflow (airflow direction γ) generated by the fan motor 148 in the circuit unit 140 is indicated by a two-dot chain line in FIG. 10. That is, in the internal space of the circuit unit 140, the space downstream (left) of the fan motor 148 is the airflow path 156, and the space upstream (right) of the fan motor 148 is the suction path 158 in which an airflow is generated in a direction in which the air is sucked toward the fan motor 148 as the fan motor 148 blows air. The airflow path 156 and the suction path 158 are the paths of the airflow generated by the air blown by the fan motor 148.

[0066] Here, the case 150 is configured to include an upper case 152 and a lower case 154, and a path branching section 160 that branches the air flowing through the airflow path 156 is provided in the lower case 154. Specifically, on the downstream side (left side) of the fan motor 148 in the lower case 154, a pair of outer guide wall sections 162, 162 whose opposing dimensions (front-rear dimension) gradually increase toward the left, and a pair of inner guide wall sections 164, 164 that extend approximately parallel to the outer guide wall sections 162 between the outer guide wall sections 162 in the front-rear direction are provided. These inner guide wall sections 164, 164 are connected to each other at their right ends, and the path branching section 160 is configured at this connection portion. That is, the airflow generated by the drive of the fan motor 148 collides with the path branching section 160, so that the airflow branches to both front and rear sides and flows downstream at both front and rear ends of the case 150.

[0067] In the second embodiment, at least one of the current-carrying busbars 142c-142f arranged in the airflow path 156 (i.e., downstream of the fan motor 148) is provided with a corrugated plate portion 68, and at least one of the heat-dissipating busbars 144e-144h arranged in the airflow path 156 is provided with a corrugated plate portion 68. In particular, in the second embodiment, the current-carrying busbar 142f is provided with a corrugated plate portion 68, and the heat-dissipating busbar 144g is provided with a corrugated plate portion 68. The current-carrying busbar 142f and the heat-dissipating busbar 144g each include a connection portion 70 fastened to the terminal portion 50 of each relay 44, and the current-carrying busbar 142f and the heat-dissipating busbar 144g each include a corrugated plate portion 68 extending continuously from the connection portion 70 in the left-right direction.

[0068] The corrugated plate portion 68 of the current-carrying busbar 142f and the corrugated plate portion 68 of the heat-dissipating busbar 144g are each located on an airflow path 156 that branches out on both sides in the front-rear direction. In the second embodiment, the corrugated plate portion 68 of the current-carrying busbar 142f is located in the front portion of the case 150, and the corrugated plate portion 68 of the heat-dissipating busbar 144g is located in the rear portion of the case 150. Each corrugated plate portion 68 is configured such that peak portions 72 that convex on one side in the plate thickness direction and valley portions 74 that convex on the other side in the plate thickness direction are alternately and continuously provided in the up-down direction, and the corrugated plate portion 68 extends in the left-right direction with a predetermined length.

[0069] In this way, it is possible to provide the corrugated plate portion 68 not only on the current-carrying busbar 142f but also on the heat-dissipating busbar 144g, thereby further improving the heat dissipation efficiency. Also in the second embodiment, the peaks 72 and valleys 74 constituting each corrugated plate portion 68 extend in the left-right direction, which is the same direction as the airflow direction γ, thereby making it possible to avoid impeding the airflow caused by the fan motor 148. In particular, in the second embodiment, the path branching portion 160 is provided in the airflow path 156, and the airflow caused by the fan motor 148 can be stably branched to both the front and rear sides of the case 150 and more reliably guided to the corrugated plate portions 68 of the current-carrying busbar 142f and the heat-dissipating busbar 144g.

[0070] <Modification> Although the first and second embodiments have been described above as specific examples of the present disclosure, the present disclosure is not limited to these specific descriptions. Modifications, improvements, etc. within the scope of the present disclosure that can achieve the object of the present disclosure are included in the present disclosure. For example, the following modified examples of the embodiments are also included in the technical scope of the present disclosure.

[0071] (1) In the circuit unit main body constituting the circuit unit according to the present disclosure, a hinge opening / closing part that can be opened and closed may be provided in a part of the case, so that the fan motor provided in the circuit unit can be easily replaced. For example, as in the circuit unit 170 shown in FIG. 13, a hinge opening / closing part 172 that can be opened and closed by rotating around an axis may be provided at the right end and front side of the upper case 86. The upper view in FIG. 13 shows the hinge opening / closing part 172 in an open state, and the lower view in FIG. 13 shows the hinge opening / closing part 172 in a closed state. As shown in the upper view in FIG. 13, by opening the hinge opening / closing part 172, the fan motor 38 can be easily replaced, and as shown in the lower view in FIG. 13, by closing the hinge opening / closing part 172, the intrusion of dust and the like into the circuit unit 170 can be suppressed. Note that this configuration may be applied to the second embodiment, and the hinge opening / closing part may be provided in the center part of the case in the left-right direction, so that the fan motor provided in the center part in the left-right direction can be easily replaced.

[0072] (2) In the above embodiment, the exhaust direction regulating parts 32, 32 are provided on both left and right wall parts of the housing body 24 of the battery pack 12 as separate parts from the circuit units 10, 140 and the electric connection box 30, but the present invention is not limited to this embodiment. For example, as in the circuit unit 180 shown in FIG. 14, the exhaust direction regulating part 182 may be formed integrally with the case 84 of the circuit unit 180 or the connection box case 124 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, it is not limited to the wall parts on both left and right sides of the housing body, and may be provided on the bottom wall part of the housing body or on the lid.

[0073] (3) In the above embodiment, the circuit unit 10, 140 having a structure according to the present disclosure is provided on the left side inside the battery pack 12, but the electrical connection box 30 provided on the right side inside the battery pack 12 may also have a structure according to the present disclosure. Note that in the present disclosure, only a circuit unit may be provided inside the battery pack, and an electrical connection box is not essential. That is, the circuit unit according to the present disclosure may have a length dimension that allows it to be accommodated on the left 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.

[0074] (4) In the above embodiment, the intake hole 90 and the exhaust hole 92 are respectively configured by a plurality of intake slits 98 and exhaust slits 100, 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.

[0075] (5) In the first embodiment, the entire current-carrying busbars 40c-40e having the corrugated portion 68 are disposed downstream of the airflow path 118 in the airflow direction α, but only the corrugated portion of the busbar (including the current-carrying busbar and the heat-dissipating busbar) may be located downstream in the airflow direction of the fan motor. Also, in the first embodiment, the current-carrying busbars 40c-40e having the corrugated portion 68 are in thermal contact with the terminal portions 50 of the relays 44 (fastened by the bolts 62 in the first embodiment), but the current-carrying busbars and the heat-dissipating busbars having the corrugated portions may be in contact with other heat-generating components (e.g., fuses, etc.) (fastened by bolts, for example). The same applies to the second embodiment.

[0076] (6) In the second embodiment, the path branching section 160 that branches the air flowing through the air supply path 156 is provided in the lower case 154. However, the path branching section may be provided in the upper case that constitutes the case, or may be provided in both the upper case and the lower case.

[0077] (7) In the first embodiment, a partition plate 114 was provided inside the case 84 to separate the internal space of the case 84 into front and rear spaces, but such a partition plate is not essential in the circuit unit according to the present disclosure. Similarly, the outer and inner guide walls 162, 164 (path branching section 160) in the second embodiment are not essential in the circuit unit according to the present disclosure. In the circuit unit according to the present disclosure, the fan motor may be provided in the center in the front-rear direction, and for example, substantially the entire area surrounded by the case may be used as the air blowing path and / or suction path. [Explanation of symbols]

[0078] 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 Circuit component 38 Fan motor 40, 40a~40e Current-carrying busbars (busbars) 42 Heat dissipation busbar (busbar) 44 Relay (first heat generating component) 46 Fuse (second heat generating component) 48 Case body 50 Terminal section 52 Insulating partition plate 54 Coil 56 Precharge relay 58 Precharge resistor 60 Terminal section 62 Volts 64,66 External connection part 68 Corrugated Sheet 70 Connection 72 Yamabe 74 Valley 76,78 Heat radiation part 80 Insulating heat conductive sheet 82 Support Frame 84 cases 86 Upper Case 88 Lower case 90 Air Intake Hole 92 Exhaust Vent 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 Intake slit 100 Exhaust slit 102 Bottom wall 104 Lower peripheral wall 106 Nut 108 Lock recess 110 Lock protrusion 112 Insertion hole 114 Partition 116 Gap 118 Air flow path 120 Main body cooling path 122 Fan motor 124 Junction box case 126 Air Intake Hole 128 Exhaust Vent 130 Monitoring and driving unit 140 Circuit unit (embodiment 2) 142, 142a~142f Current-carrying bus bars 144, 144a~144h Heat dissipation busbar 146 Circuit component 148 Fan motor 150 cases 152 Upper Case 154 Lower Case 156 Air flow path 158 Suction Path 160 Route branch 162 Outer guide wall section 164 Inner guide wall 170 Circuit unit (Fig. 13) 172 Hinge opening and closing part 180 Circuit unit (Fig. 14) 182 Exhaust direction control part L,M center axis α,β,γ Air blowing direction

Claims

1. A circuit unit accommodated in a housing of a battery pack, A circuit configuration unit including a heat generating component; A fan motor; a bus bar made of a metal plate in thermal contact with the heat generating component, the bus bar has a corrugated plate portion formed by deforming the metal plate into a corrugated shape, the corrugated plate portion of the bus bar is disposed on a downstream side of the fan motor in a blowing direction such that peaks and valleys of the corrugated plate portion extend along the blowing direction. Circuit unit.

2. the bus bar has a flat-plate-shaped connection portion that is fastened to a terminal portion of the heat generating component, The circuit unit according to claim 1 , wherein the bus bar is in thermal contact with the heat generating component via the connection portion.

3. 3. The circuit unit according to claim 1, wherein the heat generating component and the bus bar are disposed downstream of the fan motor in the air blowing direction.

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