Electrical junction box

Abstract

This electrical junction box (100) comprises: a housing (50) that has a fixing wall which is fixed to a target object and that is provided with a relay (40) and a fuse (60); and a bus bar (10) that has a plate shape, that is disposed facing the fixing wall, and that is connected to the relay (40) and the fuse (60). The electrical junction box (100) comprises a plurality of heat radiating plates that are provided upright in an intersecting direction with the bus bar (10) and that discharge heat from the bus bar (10).

Description

Electrical junction box

[0001] This application claims priority to Japanese Patent Application No. 2022-146343 filed on September 14, 2022, and incorporates by reference all of the contents of said Japanese application.

[0002] 2. Description of the Related Art Conventionally, many vehicles are provided with an electrical connection device that is interposed between a power source and electrical components to supply electric power.

[0003] Patent document 1 discloses an electrical connection device that includes a housing that accommodates an electromagnetic relay, and that has an opening in the housing near the electromagnetic relay to radiate heat from inside the housing to the outside.

[0004] Japanese Patent Application Laid-Open No. 2021-83160

[0005] An electrical connection box according to an embodiment of the present disclosure is an electrical connection box having a fixed wall that is fixed to an object, a housing in which electronic components are mounted, and a plate-shaped bus bar that is arranged opposite the fixed wall and connected to the electronic components, and is provided with a plurality of heat sinks that are erected in a direction intersecting the bus bar and that dissipate heat from the bus bar.

[0006] 1 is a perspective view of an electrical junction box according to a first embodiment; 2 is a plan view of an electrical junction box according to a first embodiment; 3 is a plan view showing a state in which an upper case is removed from the electrical junction box according to the first embodiment; 4 is a view taken along arrow IV in FIG. 3; 5 is a cross-sectional view taken along line V-V in FIG. 2; 6 is a partial plan view of an electrical junction box according to a second embodiment; 7 is a partial vertical cross-sectional view of an electrical junction box according to a third embodiment; 8 is a plan view of an electrical junction box according to a fourth embodiment in a state in which the upper case is removed;

[0007] [Problem to be Solved by the Present Disclosure] For example, in the case of an electronic component such as a relay that generates heat when energized, in reality, a significant heat dissipation effect cannot be expected from heat dissipation from the electronic component itself, and heat dissipation via a bus bar that is connected to such an electronic component and exposed to the air is more efficient.

[0008] However, in the electrical connection device of Patent Document 1, the opening is provided in the housing at a position near the electromagnetic relay, and heat is only dissipated from the electromagnetic relay itself, with no consideration given to heat dissipation via the bus bar, so it is difficult to say that the heat from the electromagnetic relay is dissipated efficiently.

[0009] Therefore, an object of the present invention is to provide an electrical junction box that can more effectively dissipate heat generated by electronic components when power is applied.

[0010] Effect of the Present Disclosure According to the present disclosure, heat generated by electronic components when energized can be more effectively dissipated.

[0011] [Description of Embodiments of the Present Invention] First, embodiments of the present disclosure will be listed and described. In addition, at least some of the embodiments described below may be combined in any manner.

[0012] (1) An electrical connection box according to an embodiment of the present disclosure is an electrical connection box having a fixed wall that is fixed to an object, a housing in which electronic components are mounted, and a plate-shaped bus bar that is arranged opposite the fixed wall and connected to the electronic components, and is provided with a plurality of heat sinks that are erected in a direction intersecting the bus bar and that dissipate heat from the bus bar.

[0013] In this embodiment, since the plurality of heat sinks are provided, heat generated in the electronic components when power is applied and transferred to the bus bar can be quickly dissipated, and heat from the electronic components can be dissipated more effectively.

[0014] (2) An electrical connection box according to an embodiment of the present disclosure includes a base plate whose first main surface contacts one main surface of the bus bar, and the plurality of heat sinks are provided on a second main surface of the base plate.

[0015] In this embodiment, heat generated by the electronic components when power is applied is transferred to the bus bar and then to the heat sinks via the base plate, and the heat sinks quickly dissipate the heat, thereby effectively dissipating heat from the electronic components.

[0016] (3) In an embodiment of the electrical connection box disclosed herein, a first through hole is formed in the opposing wall that faces the fixed wall, and the first through hole is formed at a position corresponding to the gap between adjacent heat sinks in the opposing direction of the fixed wall and the opposing wall.

[0017] In this embodiment, the first through holes are formed at positions corresponding to the gaps between adjacent heat sinks in the opposing direction. Therefore, outside air flowing into the housing through the first through holes quickly flows into the gaps between the heat sinks, cooling the heat sinks, and the air in the gaps between the heat sinks containing the radiated heat rises and quickly flows out of the housing through the first through holes. This allows for effective heat dissipation for the electronic components.

[0018] (4) In the electrical junction box according to the embodiment of the present disclosure, the first through hole extends along the heat sink.

[0019] In this embodiment, since the first through hole extends along the heat sink, the size of the first through hole can be effectively ensured in the portion of the opposing wall corresponding to the gap between adjacent heat sinks.

[0020] (5) In the electrical connection box according to an embodiment of the present disclosure, side walls extending toward the fixed wall are connected to the opposing edges of the opposing wall, and a second through hole is formed in each side wall. The second through holes are each formed at a position corresponding to the gap between adjacent heat sinks in the opposing direction of the two side walls.

[0021] In this embodiment, the second through holes are formed in the opposing direction of the two side walls at positions corresponding to the gaps between adjacent heat sinks, so that air flowing in through the second through holes in one side wall passes between the adjacent heat sinks and quickly flows out through the second through holes in the other side wall. At this time, heat convection from the heat sinks also flows to the outside of the housing, further improving the cooling effect of the electronic components.

[0022] (6) In the electrical junction box according to the embodiment of the present disclosure, the second through hole extends along the heat sink.

[0023] In this embodiment, the second through hole extends along the heat sink, so that the size of the second through hole can be effectively secured in the portion of the two side walls corresponding to the gap between adjacent heat sinks.

[0024] (7) In the electrical junction box according to the embodiment of the present disclosure, the base plate and the plurality of heat sinks are integrally formed, and the opposing wall is provided with a positioning portion that determines the position of the heat sink.

[0025] In this embodiment, the positioning portion is used to determine the position of the heat sink during assembly, thereby improving the workability of the assembly work.

[0026] (8) In the electrical junction box according to the embodiment of the present disclosure, the heat sink is provided near the connection portion between the bus bar and the electronic component.

[0027] In this embodiment, the heat sink is also provided near the connection between the bus bar and the electronic component, thereby more efficiently cooling the connection where heat is generated intensively when current is applied.

[0028] (9) In the electrical junction box according to the embodiment of the present disclosure, the number of heat sinks is greater in the vicinity of the connection portion than in other portions.

[0029] In this embodiment, the number of heat sinks near the connection between the bus bar and the electronic component is greater than in other areas, so that the connection, where heat is generated in a concentrated manner when current is applied, can be cooled more efficiently.

[0030] (10) In an electrical connection box according to an embodiment of the present disclosure, the first through holes are multiple, and among the multiple first through holes, one first through hole formed near the connection portion between the bus bar and the electronic component is larger than the other first through holes.

[0031] In this embodiment, one of the first through holes formed near the connection portion is larger than the other first through holes, thereby increasing the amount of outside air flowing into the connection portion and the amount of air containing heat dissipated from the connection portion, thereby more efficiently cooling the heat generated at the connection portion when current is applied.

[0032] (11) In an electrical connection box according to an embodiment of the present disclosure, there are multiple second through holes, and among the multiple second through holes, one second through hole formed near the connection portion between the bus bar and the electronic component is larger than the other second through holes.

[0033] In this embodiment, the second through-hole provided near the connection portion is larger than the other second through-holes, which increases the amount of outside air flowing into the connection portion and the amount of air containing heat dissipated from the connection portion, thereby more efficiently cooling the heat generated at the connection portion when current is applied.

[0034] [Details of the embodiment of the present invention] An electrical junction box according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the present invention 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.

[0035] (Embodiment 1) Fig. 1 is a perspective view of an electrical junction box 100 according to embodiment 1, and Fig. 2 is a plan view of the electrical junction box 100 according to embodiment 1. In Fig. 2, the positions of a bus bar 10 and a heat dissipation member 70, which will be described later, are indicated by dashed lines.

[0036] The electrical junction box 100 is attached to the outside of an object to which it is to be attached (target), such as a battery pack 200 of an EV (Electric Vehicle). For convenience, Fig. 1 shows the electrical junction box 100 attached to the battery pack 200.

[0037] The electrical junction box 100 includes a housing 50 that houses, for example, a relay 40 (electronic component), a fuse 60 (electronic component), a circuit board, etc. The housing 50 has a generally rectangular shape in a plan view and is made of, for example, resin.

[0038] The housing 50 includes a lower case 30 that is attached to the mounting target, and an upper case 20 that partially covers the lower case 30. Electronic components such as relays 40, fuses 60, and bus bars 10 are attached to the lower case 30, and the upper case 20 partially covers these electronic components. For convenience of explanation, the upper case 20 side will be referred to as the top and the lower case 30 side as the bottom.

[0039] FIG. 3 is a plan view showing the electrical junction box 100 according to the first embodiment with the upper case 20 removed, and FIG. 4 is a view taken along the arrow IV in FIG.

[0040] The lower case 30 has a flat box shape with one side open facing the upper case 20. The lower case 30 has a substantially rectangular bottom wall 31 (fixed wall) whose outer surface is fixed to the mounting object, and a side wall 33 extending perpendicularly from the edge of the bottom wall 31 toward the upper case 20. As described above, the relay 40, fuse 60, and bus bar 10 are provided inside the lower case 30.

[0041] Of the side walls 33 of the lower case 30, those on the longer sides of the bottom wall 31 have engaging protrusions 35 protruding from the outer surfaces thereof at multiple locations to engage with engaging portions 25 (described later) of the upper case 20. The engaging protrusions 35 consist of a pair of protrusions spaced apart in the length direction of the side walls 33. In addition, the bottom wall 31 has fixing holes 37 formed in the four corners and near the side wall 33 on one longer side to be used when attaching the lower case 30 (housing 50) to an object to be attached.

[0042] 3 and 4, the lower case 30 is provided with a relay 40 and a fuse 60 spaced apart in the longitudinal direction of the lower case 30. That is, the relay 40 is provided at one end of the lower case 30, and the fuse 60 is provided at the other end of the lower case 30. The fuse 60 is provided near one side wall 33 in the width direction of the lower case 30. The relay 40 has a connection terminal provided on the side wall 33 on the other side in the width direction (see FIG. 4).

[0043] A bus bar 10 is provided between the relay 40 and the fuse 60. The bus bar 10 is generally plate-shaped and made of a conductive metal plate such as copper, and is disposed opposite the inner surface of the bottom wall 31. The bus bar 10 includes a flat portion 13 facing the bottom wall 31, one end 11 (connection portion) screwed to the connection terminal of the relay 40, and the other end 12 (connection portion) screwed to the connection terminal 61 of the fuse 60. Hereinafter, the one end 11 and the other end 12 will also be collectively referred to as both ends 11, 12.

[0044] That is, the busbar 10 has a rectangular plate-shaped other end 12 that is connected perpendicularly to the flat portion 13 at the edge of the flat portion 13 near the fuse 60, and a rectangular plate-shaped one end 11 that is connected perpendicularly to the flat portion 13 at the edge of the flat portion 13 near the relay 40. The one end 11 extends in the width direction of the bottom wall 31, and the end on the side of the other side wall 33 is bent along the other side wall 33 and connected to the connection terminal of the relay 40.

[0045] Fixing through holes for screw fastening are formed in the one end 11 and the other end 12. For example, oval fixing through holes (not shown) are formed in the other end 12 and the one end 11, which allows for design errors and tolerances to be accommodated.

[0046] The busbar 10 is provided so that one main surface of the flat portion 13 faces the bottom wall 31. A heat dissipation member 70 that dissipates heat generated by the busbar 10 when current is applied is screwed to the flat portion 13 of the busbar 10. The heat dissipation member 70 is provided over most of the flat portion 13, including the vicinity of one end 11 and the vicinity of the other end 12.

[0047] The heat dissipation member 70 has a comb-like shape in a vertical cross section extending in the length direction of the lower case 30, and includes a base plate 71 and multiple heat dissipation fins 72 (heat dissipation plates). The base plate 71 is made of a material with good thermal conductivity, such as aluminum, and has a substantially rectangular shape. One main surface (first main surface) of the base plate 71 is in contact with the other main surface of the flat portion 13 of the bus bar 10. The multiple heat dissipation fins 72 are provided on the other main surface (second main surface) of the base plate 71.

[0048] Each heat dissipation fin 72 has a rectangular plate shape and is made of the same material as the base plate 71. For example, the heat dissipation fins 72 and the base plate 71 are integrally formed. The heat dissipation fins 72 are provided upright, approximately perpendicular to the base plate 71. The heat dissipation fins 72 are arranged in parallel at predetermined intervals in the longitudinal direction of the bottom wall 31.

[0049] The upper case 20 has a box shape with one side open facing the lower case 30. The upper case 20 is slightly smaller than the lower case 30 in both the lengthwise dimension and the widthwise dimension perpendicular to the lengthwise direction.

[0050] The upper case 20 has a top wall 21 facing the bottom wall 31 of the lower case 30, and a side wall 22 surrounding the edge of the top wall 21 and extending toward the lower case 30 (see FIG. 1).

[0051] Furthermore, in the upper case 20, a plurality of through holes 23 (first through holes) are formed in the top wall 21. More specifically, the plurality of through holes 23 are formed in most of the top wall 21, including the vicinity of the bus bar 10. The plurality of through holes 23 are formed along the top wall 21.

[0052] Of the multiple through holes 23, the through holes 23 provided near the bus bar 10 are particularly formed at positions corresponding to the gaps between adjacent heat dissipation fins 72 in the opposing direction between the ceiling wall 21 and the bottom wall 31 of the lower case 30 (hereinafter simply referred to as the opposing direction) (see FIG. 2 ). In other words, the area directly below each through hole 23 corresponds to the space between adjacent heat dissipation fins 72. Each through hole 23 has a generally rectangular shape extending along the heat dissipation fin 72. In particular, the through holes 23 provided near the bus bar 10 extend along the gaps between adjacent heat dissipation fins 72.

[0053] 5 is a cross-sectional view taken along line V-V in FIG. 2. Positioning portions 28 protrude from the inner surface of the ceiling wall 21 and determine the position of the heat dissipation member 70 (heat dissipation fins 72) during assembly. The positioning portions 28 are provided near the heat dissipation fins 72 at both ends in the direction in which the heat dissipation fins 72 are arranged side by side. Specifically, the positioning portions 28 are disposed in the opposing direction at positions corresponding to the gap between one end fin 72 and its adjacent fin, or the gap between the other end fin 72 and its adjacent fin. Each positioning portion 28 is rectangular in vertical cross section, and its tip abuts against the inner surface of the end fin 72 to determine the position of the heat dissipation member 70.

[0054] Furthermore, in the upper case 20, two side walls 22 opposing each other in the width direction of the top wall 21 are formed with a plurality of side wall through holes 24 (second through holes) extending to the edge of the top wall 21. That is, a plurality of side wall through holes 24 are formed in one side wall 22 facing the fuse 60 and the other side wall 22 facing the connection terminal of the relay 40. The side wall through holes 24 are concentrated in the vicinity of the bus bar 10, i.e., the vicinity of the through hole 23. The side wall through holes 24 are formed at regular intervals in the length direction of the upper case 20.

[0055] The sidewall through-holes 24 of the one side wall 22 and the sidewall through-holes 24 of the other side wall 22 are formed at positions that align with each other in the width direction of the ceiling wall 21 (i.e., the opposing direction of the one side wall 22 and the other side wall 22). Furthermore, the sidewall through-holes 24 of the one side side wall 22 and the sidewall through-holes 24 of the other side side wall 22 are formed at positions that correspond to the gaps between adjacent heat dissipation fins 72 in the width direction of the ceiling wall 21 (see FIGS. 2 and 5).

[0056] Therefore, the heat dissipation fins 72 are not positioned between the side wall through holes 24 of the side wall 22 on one side and the side wall through holes 24 of the side wall 22 on the other side, which correspond in the width direction of the ceiling wall 21, and a gap is formed between adjacent heat dissipation fins 72.

[0057] The sidewall through-holes 24 of the one sidewall 22 and the other sidewall 22 have a generally rectangular shape extending in the opposing direction. In particular, the sidewall through-holes 24 provided near the busbar 10 extend along the gaps between adjacent heat dissipation fins 72.

[0058] Each of the through-holes 23 and each of the side wall through-holes 24 of the upper case 20 has a width of, for example, several mm, so that the fingertips of a person handling the case cannot fit through each of them.

[0059] The side wall 22 is provided at multiple locations on its lower end with engagement portions 25 that engage with engagement protrusions 35 of the lower case 30. The engagement portions 25 are U-shaped, with both open end portions fixed to the side wall 22 and curved portions that protrude downward from the side wall 22. When assembling the upper case 20 and the lower case 30, the engagement protrusions 35 of the lower case 30 pass from the inside of the engagement portions 25 between the edge of the side wall 22 and the curved portions of the engagement portions 25, thereby engaging the engagement protrusions 35 with the engagement portions 25 (see FIG. 1 ).

[0060] Electrical junction box 100 uses a current in the range of 300 A to 1000 A. When current flows, heat is generated from relay 40 and fuse 60, and the heat from relay 40 and fuse 60 is immediately transferred to bus bar 10, which is in direct contact with them. The heat generated from relay 40 and fuse 60 may also have a negative effect on electronic components around relay 40, fuse 60, and bus bar 10, so they must be cooled quickly. However, the heat dissipation effect from the relay 40 and fuse 60 themselves cannot be expected to be significant, and heat dissipation via bus bar 10 connected to relay 40 and fuse 60 is more efficient.

[0061] In contrast, the electrical junction box 100 of this embodiment is provided with a heat dissipation member 70 on the bus bar 10. When power is applied, heat transferred from the relays 40 and fuses 60 to the bus bar 10 and heat generated in the bus bar 10 is quickly transferred to the base plate 71 of the heat dissipation member 70, which is in direct contact with the bus bar 10, and is then dissipated into the air via the heat dissipation fins 72. Therefore, the heat generated from the relays 40 and fuses 60 can be efficiently dissipated via the bus bar 10, and the heat generated in the bus bar 10 can also be appropriately dissipated, thereby preventing the above-mentioned problems in advance.

[0062] Furthermore, a large current (for example, 1000 A) cannot be used for a long period of time and is used intermittently for a short period of time due to safety concerns and the problem of a large amount of heat being generated in the bus bar 10. In this way, when a large current is used, the time during which the large current flows is short, so heat is generated in a concentrated manner at the connection points with the relay 40 and the fuse 60, i.e., at both ends 11 and 12 of the bus bar 10, rather than being generated throughout the entire bus bar 10.

[0063] To cope with this, in the electrical junction box 100 of this embodiment, heat dissipation members 70 (heat dissipation fins 72) are also provided near one end 11 and the other end 12 of the bus bar 10. Therefore, even when a large current flows and heat is concentrated at both ends 11, 12 of the bus bar 10, as described above, heat from the bus bar 10, the relay 40, and the fuse 60 can be effectively dissipated.

[0064] Furthermore, in the electrical junction box 100 of this embodiment, as described above, the through holes 23 and the side wall through holes 24 are formed in the upper case 20 near the bus bars 10. This allows air to easily flow into the bus bars 10 and the heat dissipation member 70 from the outside, thereby enhancing the air-cooling effect.

[0065] Furthermore, in the electrical junction box 100 of this embodiment, as described above, the through-holes 23 of the upper case 20 are formed at positions corresponding to the gaps between adjacent heat dissipation fins 72 in the opposing direction of the top wall 21 and the bottom wall 31. Also, the side wall through-holes 24 of the upper case 20 are formed at positions corresponding to the gaps between adjacent heat dissipation fins 72 in the width direction of the top wall 21. Therefore, external air flows in between adjacent heat dissipation fins 72, and internal air flows out from between adjacent heat dissipation fins 72 quickly and without stagnation.

[0066] Furthermore, as described above, the side wall through holes 24 of the one side wall 22 and the side wall through holes 24 of the other side wall 22 are formed at positions that are aligned with each other in the width direction of the ceiling wall 21, and a gap is formed between adjacent heat dissipation fins 72 between the side wall through holes 24 of the one side wall 22 and the side wall through holes 24 of the other side wall 22.

[0067] Therefore, for example, air flowing in through the sidewall through-holes 24 of the one sidewall 22 (the sidewall through-holes 24 of the other sidewall 22) passes between the adjacent heat dissipation fins 72 and quickly flows out through the sidewall through-holes 24 of the other sidewall 22 (the sidewall through-holes 24 of the one sidewall 22). At this time, the air containing heat convection from the heat dissipation fins 72 also flows to the outside of the housing 50, thereby further improving the cooling effect of the relays 40, the fuses 60, and the bus bars 10.

[0068] As described above, the through holes 23 provided near the bus bars 10 are formed at positions corresponding to the gaps between adjacent heat dissipation fins 72 in the opposing direction of the ceiling wall 21 and the bottom wall 31 of the lower case 30. Therefore, when air containing heat convection from the heat dissipation fins 72 rises from between the adjacent heat dissipation fins 72, it quickly flows to the outside of the housing 50 via the through holes 23 directly above. This further improves the cooling effect of the relays 40, fuses 60, and bus bars 10.

[0069] 6 is a partial plan view of an electrical junction box 100 according to a second embodiment. For convenience, Fig. 6 shows an enlarged view of the vicinity of the bus bar 10, and the positions of the bus bar 10 and the heat dissipation member 70 are indicated by dashed lines.

[0070] As in embodiment 1, the electrical connection box 100 of embodiment 2 has a plurality of through holes 23 (first through holes) formed near the bus bar 10 in the ceiling wall 21 of the upper case 20, and a plurality of side wall through holes 24 (second through holes) formed near the bus bar 10 in the side wall 22.

[0071] Similar to the first embodiment, the through holes 23 provided near the busbars 10 are formed at positions corresponding to the gaps between adjacent heat dissipation fins 72 in the opposing direction of the ceiling wall 21 and the bottom wall 31. That is, the area directly below each through hole 23 corresponds to the space between adjacent heat dissipation fins 72. Each through hole 23 extends along the heat dissipation fin 72 and has a generally rectangular shape.

[0072] In the electrical junction box 100 of the second embodiment, among the plurality of through holes 23, the through holes 23A formed near the one end 11 and the other end 12 of the bus bar 10 are larger than the other through holes 23. For example, the dimension of the through hole 23A in the direction in which the plurality of through holes 23 are arranged is larger than the other through holes 23.

[0073] The sidewall through-hole 24 is otherwise the same as in the first embodiment, and a detailed description thereof will be omitted.

[0074] As described above, in the electrical junction box 100 of the second embodiment, among the plurality of through holes 23, the through holes 23A formed near the one end 11 and the other end 12 of the bus bar 10 are larger than the other through holes 23. Therefore, the amount of air flowing in through the through holes 23A is relatively large, which allows for more concentrated cooling of the one end 11 and the other end 12 and is therefore suitable for cases where heat is concentrated at both ends 11, 12 of the bus bar 10 due to a large current flow.

[0075] The same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

[0076] 7 is a partial vertical cross-sectional view of an electrical junction box 100 according to a third embodiment. For convenience, Fig. 7 shows an enlarged view of the heat dissipation member 70 and its vicinity, and the position of the other end 12 is indicated by a dashed line.

[0077] As in embodiment 1, the electrical connection box 100 of embodiment 3 has a plurality of through holes 23 (first through holes) formed near the bus bar 10 in the ceiling wall 21 of the upper case 20, and a plurality of side wall through holes 24 (second through holes) formed near the bus bar 10 in the side wall 22.

[0078] As in the first embodiment, the upper case 20 has a plurality of side wall through holes 24 (second through holes) formed in each of the one side wall 22 and the other side wall 22 that face each other in the width direction of the ceiling wall 21. The side wall through holes 24 are formed in a concentrated manner, particularly near the bus bar 10, i.e., near the through hole 23.

[0079] The side wall through-holes 24 of the one side wall 22 and the side wall through-holes 24 of the other side wall 22 are formed at positions that align with each other in the width direction of the ceiling wall 21, and the side wall through-holes 24 of the one side wall 22 and the side wall through-holes 24 of the other side wall 22 are formed at positions that correspond to the gaps between adjacent heat dissipation fins 72 in the width direction of the ceiling wall 21 (see FIGS. 2 and 7). Each side wall through-hole 24 extends along the gaps between adjacent heat dissipation fins 72 and has a generally rectangular shape.

[0080] 7 , in the electrical junction box 100 of the third embodiment, among the plurality of side wall through holes 24, side wall through holes 24A formed near one end 11 and the other end 12 of the bus bar 10 are larger than the other side wall through holes 24. Although only the other side wall 22 is shown in FIG. 7 , in both the side wall through holes 24 of the one side wall 22 and the side wall through holes 24 of the other side wall 22, side wall through holes 24A larger than the other side wall through holes 24 are formed near both ends 11, 12.

[0081] For example, the dimension of the side wall through-hole 24A in the direction in which the plurality of side wall through-holes 24 are arranged is larger than that of the other side wall through-holes 24, or the ratio of the side wall through-hole to the gap between adjacent heat dissipation fins 72 is larger than that of the other side wall through-holes 24. The other through-holes 23 are the same as those in the first embodiment, and detailed description thereof will be omitted.

[0082] As described above, in the electrical junction box 100 of the third embodiment, among the multiple side wall through holes 24, the side wall through holes 24A formed near the one end 11 and the other end 12 of the bus bar 10 are larger than the other side wall through holes 24. Therefore, the amount of air flowing in through the side wall through holes 24A is relatively large, which allows for more concentrated cooling of the one end 11 and the other end 12 and is therefore suitable for cases where heat is concentrated at both ends 11, 12 of the bus bar 10 due to a large current flow.

[0083] The same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

[0084] 8 is a plan view of an electrical junction box 100 according to a fourth embodiment with the upper case 20 removed. For convenience, Fig. 8 shows an enlarged view of the heat dissipation member 70 and its vicinity.

[0085] The electrical junction box 100 of the fourth embodiment includes a bus bar 10, as in the first embodiment, with the flat portion 13 of the bus bar 10 disposed opposite the bottom wall 31, and a heat dissipation member 70 attached to the flat portion 13 to dissipate heat generated by the bus bar 10 when current is applied. The heat dissipation member 70 has a comb shape in a vertical cross section extending in the length direction of the lower case 30, and includes a base plate 71 and a plurality of heat dissipation fins 72 (heat dissipation plates).

[0086] The base plate 71 is made of a material with good thermal conductivity, such as aluminum, and has a rectangular shape. One main surface of the base plate 71 is in contact with the other main surface of the flat portion 13 of the bus bar 10, and a plurality of heat dissipation fins 72 are provided on the other main surface.

[0087] Each heat dissipation fin 72 has a rectangular plate shape and is made of the same material as the base plate 71. For example, the heat dissipation fins 72 and the base plate 71 are integrally formed. The heat dissipation fins 72 are provided upright, approximately perpendicular to the base plate 71. The heat dissipation fins 72 are arranged in parallel in the longitudinal direction of the base plate 71.

[0088] In the electrical junction box 100 of the fourth embodiment, the number of heat dissipation fins 72 is greater near the one end 11 and the other end 12 of the bus bar 10 (see the portions surrounded by dashed lines in FIG. 8 ) than in other portions. That is, the heat dissipation fins 72 are concentrated near the one end 11 and the other end 12 of the bus bar 10.

[0089] As described above, in the electrical junction box 100 of the fourth embodiment, more heat dissipation fins 72 are disposed near the one end 11 and the other end 12 of the bus bar 10 than in other portions, and therefore the surface area available for heat dissipation increases as the number of heat dissipation fins 72 increases, thereby improving the heat dissipation capacity near both ends 11, 12. This allows both ends 11, 12 to be cooled more intensively, making it possible to deal with cases where heat is concentrated at both ends 11, 12 of the bus bar 10 due to a large current flow.

[0090] The same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

[0091] The technical features (constituent elements) described in Embodiments 1 to 4 can be combined with each other, and by combining them, new technical features can be formed. The embodiments disclosed herein are illustrative in all respects and should be considered not to be limiting. The scope of the present invention is defined by the claims, not by the meaning described above, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0092] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any combination, regardless of the reference format. Furthermore, the claims use a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used.

[0093] REFERENCE SIGNS LIST 10 bus bar 11 one end 12 other end 13 flat portion 20 upper case 21 ceiling wall 22 side wall 23 through hole 24, 24A side wall through hole 25 engaging portion 28 positioning portion 30 lower case 31 bottom wall 33 side wall 35 engaging protrusion 37 fixing hole 40 relay 50 housing 60 fuse 61 connection terminal 70 heat dissipation member 71 base plate 72 heat dissipation fin 100 electrical junction box 200 battery pack

Claims

1. An electrical connection box including a housing having a fixed wall fixed to an object and in which an electronic component is provided, and a plate-shaped bus bar disposed opposite the fixed wall and connected to the electronic component, a plurality of heat sinks arranged in a direction intersecting the bus bars to dissipate heat from the bus bars; A side wall extending toward the fixed wall is connected to each of the opposing edges of the opposing wall of the housing, the opposing wall facing the fixed wall being opposed to the fixed wall, A second through hole is formed in each side wall; Each heat sink extends in a direction opposite to the two side walls, An electrical connection box in which the second through hole in one side wall and the second through hole in the other side wall are each formed at a position corresponding to the gap between adjacent heat sinks so as to face each other in the facing direction.

2. a base plate having a first main surface in contact with one main surface of the bus bar; 2. The electrical junction box according to claim 1, wherein the plurality of heat sinks are provided on a second main surface of the base plate.

3. A first through hole is formed in the opposing wall, The electrical junction box according to claim 2 , wherein the first through hole is formed at a position corresponding to a gap between adjacent heat sinks in an opposing direction of the fixed wall and the opposing wall.

4. 4. The electrical junction box according to claim 3, wherein the first through hole extends along the heat sink.

5. (delete)

6. 2. The electrical junction box according to claim 1, wherein the second through hole extends along the heat sink.

7. The base plate and the plurality of heat sinks are integrally formed, 3. The electrical junction box according to claim 2, wherein the opposing wall is provided with a positioning portion for determining a position of the heat sink.

8. 3. The electrical junction box according to claim 1, wherein the heat sink is provided in the vicinity of a connection portion between the bus bar and the electronic component.

9. 9. The electrical junction box according to claim 8, wherein the number of said heat sinks is greater in the vicinity of said connection portion than in other portions.

10. The first through holes are multiple, The electrical junction box according to claim 3 , wherein one of the plurality of first through holes formed in the vicinity of a connection portion between the bus bar and the electronic component is larger than the other first through holes.

11. The second through holes are multiple, The electrical junction box according to claim 1 , wherein one of the second through holes formed near a connection portion between the bus bar and the electronic component is larger than the other second through holes.