Electrical connection box

Abstract

Provided is an electrical connection box capable of improving heat transfer efficiency. An electrical connection box (10) is provided on a cooling surface (92), wherein the electrical connection box (10) is provided with a housing (11), a heat generating element (12) housed inside the housing (11), and a bus bar (13). The bus bar (13) has a heat transfer portion (27) capable of transferring heat from the heat generating element (12) to the cooling surface (92). A through hole (24) is provided in a bottom wall (22) of the housing (11), the through hole (24) penetrating the bottom wall (22) in a wall thickness direction. The heat transfer portion (27) is disposed inside the through hole (24).

Description

Technical Field

[0001] This disclosure relates to electrical connection boxes. Background Technology

[0002] Patent Document 1's electrical connection box includes a relay that generates heat during operation, a housing that houses the relay, and a busbar connected to the relay. The base plate of the housing includes a portion of a dissimilar material with a higher thermal conductivity than other parts of the housing. The dissimilar material portion contacts the busbar. The dissimilar material portion contacts a battery pack disposed outside the housing. The battery pack has a cooling mechanism.

[0003] [Existing Technical Documents]

[0004] [Patent Literature]

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-119554

[0006] [The problem the invention aims to solve]

[0007] With the increasing voltage and current of electrical connection boxes, a significant amount of heat is generated inside them. In the case of Patent Document 1, the heat generated by the operation of the relay is transferred to the dissimilar material section via the busbar. Since the thermal conductivity of the dissimilar material section is higher than that of other parts of the housing, the heat transferred to the dissimilar material section is transferred to the battery pack and cooled. A heat transfer distance commensurate with the thickness of the dissimilar material section is required between the busbar and the battery pack, thus there is room for improvement from the viewpoint of heat transfer efficiency. Summary of the Invention

[0008] Therefore, the purpose of this disclosure is to provide an electrical connection box that can improve heat transfer efficiency.

[0009] [Methods used to solve problems]

[0010] The electrical connection box disclosed herein is disposed on a cooling surface. The electrical connection box includes a housing, a heating element housed inside the housing, and a busbar. The busbar has a heat transfer section that can transfer heat from the heating element to the cooling surface. A through hole is provided in the bottom wall of the housing, the through hole penetrating the bottom wall in the wall thickness direction, and the heat transfer section is disposed inside the through hole.

[0011] [Invention Effects]

[0012] According to this disclosure, an electrical connection box that can improve heat transfer efficiency can be provided. Attached Figure Description

[0013] Figure 1 This is a perspective view of the electrical connection box according to Embodiment 1.

[0014] Figure 2 This is a perspective view showing the positional relationship between the bottom wall, busbar, and heating element in the electrical connection box of Embodiment 1.

[0015] Figure 3 This is a bottom view of the electrical connection box according to Embodiment 1.

[0016] Figure 4 This is a side sectional view of the electrical connection box according to Embodiment 1.

[0017] Figure 5 This is a cross-sectional view obtained by enlarging the heat transfer part with an insulating resin layer bonded to it and its surrounding part in the electrical junction box of Embodiment 1.

[0018] Figure 6 In the case where the heat transfer section of the electrical connection box in Embodiment 1 is surrounded by an insulating tube, it is equivalent to Figure 5 The image.

[0019] Label Explanation

[0020] 10… Electrical Connection Box

[0021] 11…shell

[0022] 12…Heating element

[0023] 13…busbar

[0024] 14…Insulation and sealing parts

[0025] 15… Upper shell

[0026] 16…Lower shell

[0027] 17…First housing fixing part

[0028] 18…Busbar fixing part

[0029] 19…Top plate section

[0030] 20…Side panel section

[0031] 21… Screw receiving part

[0032] 22…bottom wall

[0033] 23… Zhou Bi

[0034] 24…through hole

[0035] 25…Connecting part

[0036] 26…Second housing fixing part

[0037] 27…Heat Transfer Section

[0038] 28…Corner

[0039] 29, 29A… Insulation section

[0040] 30…Erecting section

[0041] 90… battery pack

[0042] 91… Bolt

[0043] 92… Cooling surface Detailed Implementation

[0044] [Description of embodiments of this disclosure]

[0045] First, embodiments of this disclosure will be described.

[0046] Regarding the electrical connection box of this disclosure, (1) is an electrical connection box disposed on a cooling surface, wherein the electrical connection box has a housing, a heating element housed inside the housing and a busbar, the busbar has a heat transfer part, the heat transfer part is capable of transferring heat from the heating element to the cooling surface, a through hole is provided on the bottom wall of the housing, the through hole penetrates the bottom wall in the wall thickness direction, and the heat transfer part is disposed inside the through hole.

[0047] According to the structure described in (1) above, compared with the case where the heat transfer part is provided on the bottom wall, the heat transfer distance equivalent to the wall thickness of the bottom wall can be shortened, and the heat transfer efficiency to the cooling surface can be improved.

[0048] (2) In the electrical connection box described in (1) above, it is preferable that an insulating part is provided between the plate surface of the heat transfer part and the cooling surface.

[0049] Based on the structure described in (2) above, insulation between the heat transfer section and the cooling surface can be ensured.

[0050] (3) In the electrical connection box described in (2) above, it is preferable that the insulating part is also disposed between the plate thickness surface of the heat transfer part and the inner surface of the through hole.

[0051] According to the structure described in (3) above, even if there is a foreign object between the plate thickness surface of the heat transfer section and the inner surface of the through hole, the insulation of the heat transfer section relative to the cooling surface can be well ensured.

[0052] (4) In the electrical connection box described in (2) or (3) above, it is preferable that the insulating part is made of an insulating resin layer, which is bonded to at least the heat transfer surface facing the cooling surface of the heat transfer part.

[0053] According to the structure described in (4) above, when the insulation part is installed, multiple busbars can be processed at once by coating, impregnation, etc., thus improving productivity.

[0054] (5) In the electrical connection box described in (2) or (3) above, it is preferable that the insulating part is composed of an insulating tube surrounding the heat transfer part.

[0055] Based on the structure described in (5) above, the outer periphery of the heat transfer section can be well insulated.

[0056] (6) In any of the electrical connection boxes described in (2) to (5) above, it is preferred that the corners of the busbar are rounded and the corners are covered by the insulating portion.

[0057] According to the structure described in (6) above, compared to the case where the corner becomes an edge shape, the insulating resin can reliably cover the corner and ensure the insulation of the corner.

[0058] (7) In any of the electrical connection boxes described in (2) to (6) above, it is preferred that the bus bar has an upright portion that is bent away from the bottom wall relative to the heat transfer portion, and the insulating portion is provided in such a way that it covers the portion from the heat transfer portion to the upright portion.

[0059] Based on the structure described in (7) above, the creepage distance between the busbar and the cooling surface can be properly ensured.

[0060] (8) In any of the electrical connection boxes described in (2) to (7) above, it is preferred that an insulating sealing part is provided between the insulating part and the cooling surface, the insulating sealing part filling the gap between the insulating part and the cooling surface.

[0061] According to the structure described in (8), the gap between the insulation part and the cooling surface is filled, thus further improving the heat transfer efficiency to the cooling surface.

[0062] [Details of the embodiments disclosed herein]

[0063] Hereinafter, specific examples of embodiments of the present disclosure will be described with reference to the accompanying drawings. Furthermore, the present invention is not limited to these examples, but is intended to include all modifications within the meaning and scope equivalent to the claims, as shown in the claims. The electrical connection box 10 of Embodiment 1 of the present disclosure is, for example, provided in a battery pack 90 mounted in a vehicle such as an electric vehicle. Figure 1 In this context, X, Y, and Z represent forward, right, and upward, respectively. These directional references are for convenience and may not necessarily be consistent with the directional references when the electrical connection box 10 is mounted on a vehicle (not shown) or similar object.

[0064] [Implementation Method 1]

[0065] like Figure 1 As shown, the electrical connection box 10 is disposed on the upper surface of the battery pack 90 (cooling section), i.e., the cooling surface 92 (for ease of drawing, only a portion of the battery pack 90 is shown). Although the entire battery pack 90 is not shown, it is made of metal and is box-shaped. The cooling surface 92 is planar. Figure 2 As shown, the electrical connection box 10 includes a housing 11, a heating element 12 housed inside the housing 11, and multiple busbars 13 connected to the heating element 12. Figure 4 As shown, an insulating sealing portion 14 is sandwiched between the heat transfer portion 27 (described later) and the cooling surface 92 of the busbar 13, filling the gap between the heat transfer portion 27 and the cooling surface 92. The insulating sealing portion 14 is disposed on the cooling surface 92 within the area where the electrical connection box 10 is located. In this embodiment 1, the insulating sealing portion 14 is an insulating gap filler. The gap filler is, for example, made of silicone grease, which has high thermal conductivity and insulation, is paste-like, and is configured to fill gaps and uneven surfaces. The housing 11 is made of insulating resin. Figure 4 As shown, the housing 11 consists of an upper housing 15 and a lower housing 16. The upper housing 15 is assembled onto the lower housing 16 from above. The upper housing 15 and the lower housing 16 are locked together by a housing lock (not shown).

[0066] (Heating element 12)

[0067] like Figure 2 As shown, the heating element 12 is in the shape of a rectangular box. In this embodiment 1, the heating element 12 is a relay. The heating element 12 generates heat when it is in operation. Although not shown, the heating element 12 is connected to an external power source. A pair of first housing fixing parts 17 are provided on the left and right sides of the heating element 12. The heating element 12 is fixed to the upper housing 15 by screwing the bolts 91 into the screw receiving parts 21 (described later) and each of the first housing fixing parts 17.

[0068] A pair of busbar fixing parts 18 are provided on the front surface of the heating element 12. The heating element 12 and the busbar 13 are connected by screwing bolts 91 into the connecting parts 25 of the busbar 13 (described later) at each busbar fixing part 18 and the connecting parts 25 of the busbar 13.

[0069] (Upper shell 15)

[0070] like Figure 1 As shown, the upper housing 15 has a top plate portion 19 that is rectangular in plan view and four side plate portions 20 that extend downward from each side of the top plate portion 19. The top plate portion 19 is arranged with its plate surface facing the vertical direction. The top plate portion 19 has a recess that is recessed downward in accordance with the respective arrangement of the heating element 12 and each busbar 13 housed inside the housing 11.

[0071] Multiple screw receiving portions 21 protruding downward are provided on the inner surface of the top plate portion 19. Each screw receiving portion 21 is positioned corresponding to each of the first housing fixing portions 17 and the multiple second housing fixing portions 26 (described later) of the busbar 13. By screwing bolts 91 into each of the first housing fixing portions 17, each of the second housing fixing portions 26 and each screw receiving portion 21, the heating element 12 and each busbar 13 can be respectively fixed to the upper housing 15.

[0072] Each side plate portion 20 is a flat plate extending in the vertical direction. The left and right side plates 20 of each side plate portion 20 are recessed downward at positions corresponding to the recesses of the top plate portion 19. The side plate portions 20 are arranged to surround the heating element 12 and each busbar 13 when the upper housing 15 is assembled to the lower housing 16.

[0073] (Lower shell 16)

[0074] like Figure 2 As shown, the lower housing 16 has a rectangular bottom wall 22 when viewed from above and peripheral walls 23 protruding upwards from each side of the bottom wall 22. The bottom wall 22 is flat, with the plate surface facing upwards. Figure 3 and Figure 4 As shown, a through hole 24 is provided in the middle of the left, right, front, and back sides of the bottom wall 22, penetrating the bottom wall 22 in the vertical direction (wall thickness direction). Figure 3 As shown, the through hole 24, when viewed from below (top), has the shape of the front and rear ends and side edges of the heat transfer section 27 of the busbar 13, which will be described later. The inner surface of the through hole 24 is close to and parallel to the plate thickness surface of the busbar 13, which will be described later. In addition, the inner surface of the through hole 24 also faces the portion where the heat transfer section 27 connects to the raised portion 30 of the busbar 13, which will be described later.

[0075] The peripheral wall 23 is continuous along the entire circumference of each side of the bottom wall 22. The vertical dimension of the peripheral wall 23 is smaller than the vertical dimension of the downwardly recessed portions of the left and right side plates 20 of the upper housing 15. That is, in the assembled state of the upper housing 15 and the lower housing 16, the peripheral wall 23 and the top plate 19 are positioned vertically with a gap between them. Furthermore, the peripheral wall 23 is arranged in a manner that surrounds each side plate 20.

[0076] (Bus line 13)

[0077] Each busbar 13 is made of metal and is flat. The thermal conductivity of each busbar 13 is greater than that of the housing 11. In this embodiment 1, as... Figure 2 As shown, each busbar 13 has two arranged in the left-right direction. In the following description, for convenience, [the following will be used to describe the busbars]. Figure 2The left-hand busbar 13 is described in detail, and further details are provided as needed. Figure 2 The right-hand busbar 13 will be described below. The two busbars 13 have different shapes but the same constituent elements; therefore, the corresponding constituent elements are labeled with the same numbers and names. Furthermore, Figure 4 The busbar 13 shown is Figure 2 The left-hand busbar 13.

[0078] like Figure 4 As shown, the busbar 13 has a connecting portion 25 that connects to the busbar fixing portion 18 of the heating element 12. The connecting portion 25 is arranged such that its plate surface runs along the front surface of the heating element 12. Although not shown, the connecting portion 25 has a hole that extends through the connecting portion 25 in the plate thickness direction. With the connecting portion 25 in contact with the busbar fixing portion 18, the busbar 13 is connected to the heating element 12 by screwing a bolt 91 into the hole. The surface of the connecting portion 25 is not covered with insulating resin or the like.

[0079] The busbar 13 has a second housing fixing portion 26 that extends forward by curving from the upper end of the connecting portion 25. The second housing fixing portion 26 is arranged such that the plate surface faces vertically. Although not shown, the second housing fixing portion 26 has a hole that passes through it in the plate thickness direction. With the second housing fixing portion 26 in contact with the screw receiving portion 21, a bolt 91 is screwed into this hole, thereby fixing the busbar 13 to the upper housing 15. Furthermore, Figure 2 The second housing fixing part 26 of the right-side busbar 13 extends rearward from the upper end of the standing part 30, which will be described later.

[0080] The busbar 13 has a heat transfer section 27 disposed below the bottom surface of the heating element 12. The thermal conductivity of the heat transfer section 27 is greater than that of the housing 11. The heat transfer section 27 extends in the front-back direction with its plate surface facing up and down. Furthermore, the plate surface of the heat transfer section 27 has an upper surface and a lower surface. The heat transfer section 27 is opposite to the bottom surface of the heating element 12. Figure 2 The heat transfer portion 27 of the right-hand manifold 13 is formed to be longer in the front-to-back direction than the heat transfer portion 27 of the left-hand manifold 13. Additionally, as... Figure 3 As shown, the heat transfer sections 27 arranged in the left-right direction are spaced apart from each other without contacting each other.

[0081] like Figure 3 and Figure 4As shown, the heat transfer section 27 is disposed inside the through hole 24 of the lower housing 16. The heat transfer section 27 is disposed at a distance from the bottom wall 22 without contacting it. The upper surface of the heat transfer section 27 faces the upper surface of the bottom wall 22 of the lower housing 16. The lower surface of the heat transfer section 27 faces the lower surface of the bottom wall 22. The thickness of the heat transfer section 27 is greater than the wall thickness of the bottom wall 22 of the lower housing 16. That is, the lower surface of the heat transfer section 27 protrudes downward beyond the lower surface of the bottom wall 22.

[0082] like Figure 5 As shown, the corner 28 of the busbar 13 in the width direction is a rounded corner (R-face) shape. Figure 5 In this design, only the heat transfer section 27 shows the shape of the corner 28, but the corner 28 of the entire busbar 13 is rounded. The entire circumference of the heat transfer section 27, including the corner 28, becomes an insulating section 29 covered with insulating resin. The insulating section 29 is provided between the plate thickness surface of the heat transfer section 27 and the inner surface of the through hole 24. Furthermore, the plate thickness surface of the heat transfer section 27 is the left and right side surfaces. Figure 6 As shown, the insulating part 29A may also be provided with an insulating tube instead of insulating resin. The insulating part 29A surrounds the heat transfer part 27. As the insulating tube, for example, a heat-shrinkable tube, a resin tube, etc. can be used.

[0083] like Figure 4 As shown, the lower surface of the heat transfer part 27 (insulation part 29) protrudes downwards than the lower surface of the bottom wall 22. Therefore, during the process of setting the electrical connection box 10 on the cooling surface 92, the insulation part 29 will definitely come into contact with the insulation sealing part 14 before the bottom wall 22.

[0084] The busbar 13 has a pair of upright portions 30 that curve upwards (away from the bottom wall 22 and cooling surface 92) from both ends of the heat transfer section 27 in the front-rear direction. Each upright portion 30 is arranged such that the plate surface faces in the front-rear direction. The upper end of the front upright portion 30 is formed to connect with the connecting portion 25. The rear upright portion 30 is arranged along the rear surface of the heating element 12. Figure 2 In the right-hand busbar 13, the upper end of the rear upright portion 30 is connected to the second housing fixing portion 26. The entire circumference of the upright portion 30, including the corner portion 28, becomes an insulating portion 29 covered with insulating resin. Each upright portion 30 is arranged at intervals without contacting the front and rear of the heating element 12.

[0085] (Manufacturing method of busbar 13)

[0086] Next, an example of the manufacturing method of the busbar 13 will be described. In the case of this embodiment 1, the busbar 13 is formed into a predetermined shape by forming a metal rod with a circular cross-section. Specifically, the rod is formed into a flat plate shape by a multi-forming machine, and then bent while changing the orientation of the rod as needed. In order to form the rod with a circular cross-section, the corners 28 of the busbar 13 are rounded.

[0087] The insulating portion 29 is formed by powder coating the busbar 13. Specifically, the busbar 13 is coated with an insulating resin such as epoxy resin using an electrostatic coating method. Powdered insulating resin is sprayed onto the busbar 13, causing the insulating resin to adhere to the surfaces of the heat transfer portion 27 and the upright portion 30, respectively. After the insulating resin and the busbar 13 are heated, the insulating portion 29 is formed by drying / cooling.

[0088] like Figure 5 As shown, the corner 28 of the busbar 13 has a rounded shape, so through the above-described insulating coating, the corner 28 also becomes an insulating part 29 covered by insulating resin. Thus, compared with the case where the corner of the busbar is edge-shaped, the corner 28 can be reliably covered by insulating resin.

[0089] Furthermore, in this embodiment 1, not only the heat transfer portion 27, but also the surface of the raised portion 30 is formed as an insulating portion 29 covered with insulating resin. This ensures an appropriate creepage distance between the busbar 13 and the battery pack 90 (cooling surface 92).

[0090] like Figure 6 As shown, the insulating part 29A can also be provided by an insulating tube surrounding the heat transfer part 27. In this case, the entire outer periphery of the heat transfer part 27 can be well insulated.

[0091] (Function of electrical connection box 10)

[0092] When the heating element 12 operates, heat is generated in the heating element 12. The heat generated by the heating element 12 is transferred from the busbar fixing portion 18 of the heating element 12 to the connecting portion 25 of the busbar 13. The heat transferred to the connecting portion 25 is transferred to the heat transfer portion 27 disposed inside the through hole 24. Then, the heat is dissipated from the heat transfer portion 27 to the cooling surface 92 via the insulating sealing portion 14. As described above, the heat generated inside the electrical connection box 10 is dissipated to the battery pack 90 outside the electrical connection box 10.

[0093] like Figure 4As shown, a heat transfer section 27 is disposed inside the through hole 24, allowing the heat transfer section 27 to dissipate heat to the cooling surface 92 without passing through the bottom wall 22. Therefore, compared to the case where the heat transfer section is disposed on the upper surface of the bottom wall, the distance between the heat transfer section 27 and the cooling surface 92 can be reduced by the amount of wall thickness of the bottom wall 22, thereby improving the heat transfer efficiency to the cooling surface 92. In addition, the lower surface of the heat transfer section 27 protrudes downward from the lower surface of the bottom wall 22, so the insulating section 29 must contact the insulating seal section 14 before the bottom wall 22. As a result, the housing 11 can be separated from the battery pack 90, ensuring the insulation within the housing 11. Moreover, by filling the gap between the insulating sections 29, 29A (heat transfer section 27) and the cooling surface 92 by the insulating seal section 14, the heat transfer efficiency to the cooling surface 92 can be further improved.

[0094] As described above, the electrical connection box 10, mounted on the cooling surface 92, includes a housing 11, a heating element 12 housed within the housing 11, and a busbar 13. The busbar 13 has a heat transfer section 27 capable of transferring heat from the heating element 12 to the cooling surface 92. A through hole 24, extending through the bottom wall 22 in the wall thickness direction (vertical direction), is provided on the bottom wall 22 of the housing 11. The heat transfer section 27 is disposed inside the through hole 24. Therefore, compared to the case where the heat transfer section is disposed on the upper surface of the bottom wall, the distance between the heat transfer section 27 and the cooling surface 92 can be reduced by the amount of wall thickness of the bottom wall 22, thereby improving the heat transfer efficiency to the cooling surface 92.

[0095] Insulating portions 29 and 29A are provided between the plate surface (lower surface) of the heat transfer section 27 and the cooling surface 92. This ensures the insulation between the heat transfer section 27 and the cooling surface 92.

[0096] Insulating portions 29 and 29A are also provided between the plate thickness surface (left and right sides) of the heat transfer portion 27 and the inner surface of the through hole 24. Thus, even if foreign objects are accidentally present between the plate thickness surface of the heat transfer portion and the inner surface of the through hole, the insulation of the heat transfer portion relative to the cooling surface can be well ensured.

[0097] The insulating part 29 is composed of an insulating resin layer bonded to the heat transfer surface (lower surface) of the heat transfer part 27, at least facing the cooling surface 92. Therefore, when the insulating part 29 is provided, multiple busbars 13 can be processed at once by coating, impregnation, etc., thereby improving productivity.

[0098] The insulating part 29A is composed of an insulating tube surrounding the heat transfer part 27. As a result, the outer periphery of the heat transfer part 27 can be well insulated.

[0099] The corner 28 of the busbar 13 is rounded, and the corner 28 is covered by insulating portions 29 and 29A. Therefore, compared with the case where the corner is edge-shaped, the insulating resin can reliably cover the corner 28, ensuring the insulation of the corner 28.

[0100] The busbar 13 has an upright portion 30 that curves upwards relative to the heat transfer portion 27 away from the bottom wall 22, and insulating portions 29, 29A are provided to cover the portion from the heat transfer portion 27 to the upright portion 30. As a result, the creepage distance between the busbar 13 and the cooling surface 92 can be properly ensured.

[0101] An insulating sealing portion 14 is provided between the insulating portions 29, 29A and the cooling surface 92 to fill the gap between them. As a result, the gap between the insulating portions 29, 29A and the cooling surface 92 is filled, thereby further improving the heat transfer efficiency to the battery pack 90 (cooling part).

[0102] [Other embodiments of this disclosure]

[0103] The embodiments disclosed herein should be considered illustrative rather than restrictive in all respects.

[0104] In this embodiment 1, heat from the heating element 12 is dissipated to the cooling surface 92 via the busbar 13. In contrast, in other embodiments, heat from the heating element may be dissipated to the cooling surface via components other than the busbar. For example, a resin with high thermal conductivity may be used instead of the busbar.

[0105] In this embodiment 1, the insulating portion 29 is provided with insulating resin. In contrast, in other embodiments, the insulating portion may be an insulating sheet instead of insulating resin.

[0106] In this embodiment 1, the housing 11 is made of resin. In contrast, in other embodiments, the housing may be made of metal instead of resin.

[0107] In this embodiment 1, the insulating seal 14 is a gap filler. In contrast, in other embodiments, the insulating seal may be an insulating thermal grease instead of a gap filler.

[0108] In this embodiment 1, the insulating portion 29 is composed of an insulating resin layer covering the entire circumference of the heat transfer portion 27. In contrast, in other embodiments, only the heat transfer surface (the opposite surface to the cooling surface) of the heat transfer portion may be an insulating portion covered by the insulating resin layer. That is, the entire circumference of the heat transfer portion may not be covered by an insulating resin layer.

[0109] In this embodiment 1, the heat transfer section 27 is part of the busbar 13. In contrast, in other embodiments, the heat transfer section may be the entire busbar (where the entire busbar is housed within the through hole).

[0110] In this embodiment 1, each busbar 13 is disposed together inside the through hole 24. In contrast, in other embodiments, through holes may be provided corresponding to each busbar individually.

Claims

1. An electrical connection box, disposed on a cooling surface, wherein, The electrical connection box includes a housing, a heating element housed inside the housing, and a busbar. The busbar has a heat transfer section that can transfer heat from the heating element to the cooling surface. A through hole is provided in the bottom wall of the housing, and the through hole extends through the bottom wall in the wall thickness direction. The heat transfer section is disposed inside the through hole.

2. The electrical connection box according to claim 1, wherein, An insulating part is provided between the plate surface of the heat transfer part and the cooling surface.

3. The electrical connection box according to claim 2, wherein, The insulating part is also disposed between the plate thickness surface of the heat transfer part and the inner surface of the through hole.

4. The electrical connection box according to claim 3, wherein, The insulating part is composed of an insulating resin layer, which is bonded to at least the heat transfer surface facing the cooling surface of the heat transfer part.

5. The electrical connection box according to claim 3, wherein, The insulating part is composed of an insulating tube surrounding the heat transfer part.

6. The electrical connection box according to claim 3, wherein, The corners of the busbar are rounded. The corner is covered by the insulating portion.

7. The electrical connection box according to claim 3, wherein, The manifold has an upright portion that bends away from the bottom wall relative to the heat transfer portion. The insulating portion is provided in such a way that it covers the portion from the heat transfer portion to the upright portion.

8. The electrical connection box according to any one of claims 2 to 7, wherein, An insulating sealing portion is sandwiched between the insulating portion and the cooling surface, and the insulating sealing portion fills the gap between the insulating portion and the cooling surface.

Images