Electrical junction box

Abstract

An electrical junction box (10) is provided with: a case (20); a heat-generating component (27) accommodated in the case (20); and a heat pipe (23) disposed in the case (20). The heat pipe (23) has heat absorption parts (54, 57) positioned on the heat-generating component (27) side, and heat radiation parts (55, 58) positioned away from the heat-generating component (27). Further, the heat pipe (23) has first extension parts (56) and second extension parts (59) extending in opposite directions from the heat absorption parts (54, 57) to the heat radiation parts (55, 58), respectively.

Description

Electrical junction box

[0001] The present disclosure relates to an electrical junction box.

[0002] The electrical junction box described in Patent Document 1 includes an upper cover, a heat pipe, a case, and a metal plate. The heat pipe and the metal plate are attached to the upper cover. The heat pipe has a heat absorption part at one end and a heat dissipation part at the other end. The heat absorption part is located inside the upper cover. The heat dissipation part is located outside the upper cover.

[0003] Heat-generating components are housed inside the case. When the upper cover is attached to the case, the heat pipe comes into contact with the heat-generating components via the metal plate. The heat generated by the heat-generating components is transferred to the metal plate. The heat transferred to the metal plate is absorbed by the heat absorption section of the heat pipe. The heat absorbed by the heat absorption section is transported to the heat dissipation section and dissipated from the heat dissipation section. Technology related to the electrical junction box is also disclosed in Patent Document 2.

[0004] Japanese Utility Model Application Publication No. 4-131120 Japanese Patent Application Publication No. 2000-175332

[0005] Heat pipes dissipate heat from heat-generating components by repeatedly evaporating and condensing the internal working fluid. Therefore, it is considered preferable to position the heat absorption part on the lower side in the direction of gravity and the heat dissipation part on the upper side in terms of heat transport capacity. However, for example, when a heat pipe is installed in a vehicle, the heat pipe may be tilted vertically. This raises concerns about the heat pipe's unstable heat transport capacity.

[0006] An object of the present disclosure is to enable a heat pipe to stably exhibit its heat transport capacity even when an electrical junction box is tilted.

[0007] The electrical connection box of the present disclosure comprises a case, a heat-generating component housed in the case, and a heat pipe arranged in the case, wherein the heat pipe has a heat absorption portion located on the heat-generating component side and a heat dissipation portion located away from the heat-generating component, and further, the heat pipe has a first extension portion and a second extension portion extending in opposite directions from the heat absorption portion to the heat dissipation portion.

[0008] According to the present disclosure, even if the electrical junction box is tilted, the heat pipe can stably exhibit its heat transport capacity.

[0009] FIG. 1 is a plan view of a battery pack including an electrical junction box according to a first embodiment. FIG. 2 is a schematic diagram of a vehicle equipped with a battery pack including an electrical junction box according to the first embodiment. FIG. 3 is a perspective view of the electrical junction box according to the first embodiment. FIG. 4 is a perspective view of a case in the electrical junction box according to the first embodiment. FIG. 5 is a plan view illustrating a state in which a heat-generating component and a heat pipe are supported on the bottom of the case in the electrical junction box according to the first embodiment. FIG. 6 is an enlarged cross-sectional view illustrating a state in which the heat pipe is disposed on the bottom of the case, the bottom is disposed on a support portion, and an insulating portion is disposed between the heat pipe and the support portion in the electrical junction box according to the first embodiment. FIG. 7 is an enlarged, partially cutaway side view illustrating a state in which the input-side bus bar and the output-side bus bar are connected to a main relay, the input-side heat-dissipating bus bar is disposed on the first heat pipe, and the output-side heat-dissipating bus bar is disposed on the second heat pipe in the electrical junction box according to the first embodiment. FIG. 8 is a schematic diagram illustrating a state in which the heat pipe is tilted upward from the first heat pipe toward the second heat pipe in the electrical junction box according to the first embodiment. FIG. 9 is a schematic diagram illustrating a state in which the heat pipes are inclined downward toward the front from the first heat pipe toward the second heat pipe in the electrical junction box according to the first embodiment.

[0010] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be described. The electrical junction box of the present disclosure includes: (1) a case, a heat-generating component housed in the case, and a heat pipe disposed in the case. The heat pipe has a heat absorption portion located on the heat-generating component side and a heat dissipation portion located away from the heat-generating component. The heat pipe further has a first extension portion and a second extension portion extending in opposite directions from the heat absorption portion to the heat dissipation portion. According to the above (1), when the electrical junction box is tilted in the extension direction of the heat pipe, either the heat absorption portion of the first extension portion or the heat absorption portion of the second extension portion is located below the direction of gravity, and the other heat dissipation portion of the first extension portion or the heat dissipation portion of the second extension portion is located above the direction of gravity. Therefore, the electrical junction box can stably exhibit the heat transport capacity of the heat pipe.

[0011] (2) In the electrical junction box described in (1) above, it is preferable that the case has a bottom, the bottom is provided with a through-hole, the heat pipe is supported by the bottom, and the through-hole in the bottom is disposed between the heat pipe and a metal support that supports the bottom. According to (2) above, the heat absorption part absorbs heat generated by the heat-generating component, and the absorbed heat is transported to the heat dissipation part, and the heat can be efficiently dissipated from the heat dissipation part to the support part through the through-hole.

[0012] (3) In the electrical junction box described in (2) above, the heat pipe may be disposed inside the through hole in the bottom portion. According to (3) above, the heat pipe and the support portion are disposed in close proximity to each other, so that heat can be dissipated more efficiently from the heat dissipation portion to the support portion.

[0013] (4) In the electrical junction box described in (3) above, it is preferable that an insulating portion is disposed between the heat pipe and the support portion. According to (4) above, insulation between the heat pipe and the support portion can be maintained.

[0014] (5) In the electrical junction box described in any one of (1) to (4) above, the heat pipe preferably includes a first heat pipe having the first extension portion and a second heat pipe having the second extension portion, the first heat pipe having a first heat absorption portion as the heat absorption portion, and the second heat pipe having a second heat absorption portion separate from the first heat absorption portion as the heat absorption portion. According to (5) above, since the first heat absorption portion and the second heat absorption portion are separate from each other, the heat transport capacity of each of the first heat pipe and the second heat pipe can be effectively exhibited.

[0015] (6) In the electrical junction box described in (5) above, it is preferable that the heat-generating component includes a relay and a busbar connected to the relay, the busbar including an input-side heat dissipation busbar on the current input side and an output-side heat dissipation busbar on the current output side, the input-side heat dissipation busbar being disposed in contact with or facing the first heat pipe, and the output-side heat dissipation busbar being disposed in contact with or facing the second heat pipe. According to (6) above, heat generated on the current input side and the current output side of the relay is efficiently dissipated from the corresponding heat dissipation sections via the input-side heat dissipation busbar and the output-side heat dissipation busbar, respectively. This improves the heat dissipation performance of the relay compared to dissipating heat from just one of the current input side and the current output side.

[0016] (7) In the electrical junction box described in any one of (1) to (6) above, when the electrical junction box is mounted on a vehicle, the heat pipe preferably extends in the longitudinal direction of the vehicle. According to (7) above, for example, when the vehicle travels up a slope, the heat pipe tilts along with the vehicle, allowing the heat pipe to transport heat in accordance with the longitudinal tilt of the vehicle. [Details of the Embodiments of the Present Disclosure] Specific examples of the embodiments of the present disclosure are 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 all modifications within the meaning and scope of the claims are intended to be included.

[0017] [Embodiment 1] A specific example of embodiment 1 of the present disclosure will be described below with reference to Figures 1 to 9. An electrical junction box 10 according to embodiment 1 of the present disclosure is provided in a battery pack 11 mounted on a vehicle such as an electric vehicle. Note that in each figure, the X direction, Y direction, and Z direction represent the front, right, and upward, respectively.

[0018] (Battery Pack 11) As shown in Fig. 1, the battery pack 11 includes an electrical junction box 10, a plurality of battery modules 12, a housing 13, and a connector 14. As shown in Fig. 2, the battery pack 11 is disposed at the bottom of a vehicle 15. Each battery module 12 and the electrical junction box 10 are housed inside the housing 13. The housing 13 is made of metal. The housing 13 has a support portion 16 that forms the bottom wall.

[0019] As shown in Fig. 1 , each battery module 12 is disposed on a support portion 16. The battery module 12 is an assembly of a plurality of battery cells. In the case of the first embodiment, the battery modules 12 are arranged side by side in the front-rear direction. The battery modules 12 are connected to each other via inter-module bus bars 60.

[0020] The connector 14 is attached to a side wall of the housing 13. The connector 14 is connected to an external connector (not shown) outside the housing 13. The connector 14 is connected to the electrical junction box 10 inside the housing 13.

[0021] The electrical junction box 10 is also disposed on the support portion 16. As shown in FIG. 1 , in the case of the first embodiment, the electrical junction box 10 is disposed adjacent to the left side of each battery module 12. The rearmost battery module 12 among the battery modules 12 and the electrical junction box 10 are connected to each other via a module-side bus bar 17. The connector 14 and the electrical junction box 10 are connected to each other via a connector-side bus bar 18. Current from the battery module 12 is input to the electrical junction box 10 via the module-side bus bar 17. Current from the electrical junction box 10 is output to the outside of the battery pack 11 via the connector-side bus bar 18.

[0022] (Overall Structure of Electrical Junction Box 10) As shown in FIGS. 1 and 3 , the electrical junction box 10 includes a plurality of electronic components 19, a case 20, an input bus bar 21, an output bus bar 22, and a heat pipe 23. The plurality of electronic components 19 include, for example, a main relay 24, a relay 25, and a resistor 26. In the first embodiment, the input bus bar 21 and the output bus bar 22 are connected to the main relay 24. Heat generated in the main relay 24 can be transferred to the input bus bar 21 and the output bus bar 22. In the following description, the main relay 24, an input heat dissipation bus bar 42 (described later) of the input bus bar 21, and an output heat dissipation bus bar 44 (described later) of the output bus bar 22 are referred to as heat-generating components 27. In the first embodiment, the heat-generating components 27 are located above the heat pipes 23 and overlap the heat pipes 23 in a plan view (see FIG. 5 ).

[0023] (Case 20) The case 20 is made of synthetic resin. In the case of the first embodiment, as shown in FIG. 4, the case 20 is a lower case. The case 20 has a bottom 28 and side portions 29. The bottom 28 has a rectangular plate shape in a plan view. In particular, the bottom 28 has a shape that is longer in the front-to-rear direction than in the left-to-right direction. The side portions 29 have a shape that stands up from the outer edge of the bottom 28.

[0024] 4, the bottom portion 28 has a plurality of mounting portions 30. Each mounting portion 30 protrudes from the upper surface of the bottom portion 28. Each electronic component 19, input side bus bar 21, and output side bus bar 22 are fixed to each mounting portion 30 (see FIG. 3).

[0025] Each mounting portion 30 has a plurality of first mounting portions 31 and a plurality of second mounting portions 32. Each first mounting portion 31 has a rectangular parallelepiped shape. In the first embodiment, two of the first mounting portions 31, which are located in the middle of the front and rear of the electrical junction box 10, are used to mount the main relay 24. One of the first mounting portions 31, which is located at the rear end of the electrical junction box 10, is used to mount the input-side main body bus bar 41 and the module-side bus bar 17 (described later). Another of the first mounting portions 31, which is located at the front end of the electrical junction box 10, is used to mount the output-side main body bus bar 43 and the connector-side bus bar 18.

[0026] Each second mounting portion 32 has a plate shape and protrudes from the upper surface of the bottom portion 28 more than each first mounting portion 31. In the first embodiment, each second mounting portion 32 is disposed on the right end portion of the bottom portion 28, on both the front and rear sides of the main relay 24 (see FIG. 3 ).

[0027] As shown in FIG. 7, the input bus bar 21 and the output bus bar 22 are arranged along the plate surface of each second mounting portion 32 and fixed to each second mounting portion 32 by second bolts B2.

[0028] As shown in Fig. 4, the bottom portion 28 has a plurality of through holes 33 penetrating through the bottom portion 28 in its thickness direction. Each through hole 33 extends in the front-to-rear direction (longitudinal direction) of the bottom portion 28. Each through hole 33 has a plurality of first through holes 34 located on the rear side of the bottom portion 28 and a plurality of second through holes 35 located on the front side of the bottom portion 28. Each of the first through holes 34 and each of the second through holes 35 are separated into front and rear portions with a midpoint of the bottom portion 28 in the front-to-rear direction in between.

[0029] In the first embodiment, the first through holes 34 and the second through holes 35 are misaligned with each other in the left-right direction. Specifically, the first through holes 34 and the second through holes 35 are misaligned with each other in the left-right direction by one through hole. In the first embodiment, the multiple through holes 33 consist of three first through holes 34 and three second through holes 35. The two first through holes 34 on the right side and the two second through holes 35 on the left side are arranged coaxially in the front-rear direction.

[0030] As shown in Figures 4 and 6, the bottom 28 has multiple edge portions 36 at positions corresponding to each through hole 33. The edge portions 36 are formed to outline the opening on the upper surface of each through hole 33. The bottom 28 has a pair of left and right curved portions 37 that widen upward on the left and right inner surfaces of the through holes 33, including each edge portion 36. Each curved portion 37 has an arc shape that follows the outer peripheral surface of the lower half of the heat pipe 23. The heat pipe 23 is placed on each curved portion 37.

[0031] The bottom portion 28 has a plurality of recesses 38 on its lower surface. Each recess 38 is disposed at a position corresponding to a corresponding through-hole 33. The through-hole 33 opens to the innermost surface of the recess 38. An insulating portion 39 (described later) is housed in the recess 38. The depth of the recess 38 is shallow enough to correspond to the thickness of the insulating portion 39.

[0032] (Heat-generating component 27) As shown in Fig. 3, the main relay 24 constituting the heat-generating component 27 has a rectangular parallelepiped shape. As shown in Figs. 5 and 7, the main relay 24 has a protrusion 40. The protrusion 40 protrudes from the middle between the front and rear of the right surface of the main relay 24. The protrusion 40 has a rib shape extending in the up-down direction. The protrusion 40 is disposed between the input bus bar 21 and the output bus bar 22, and keeps the two bus bars 21, 22 in an insulated state.

[0033] The main relay 24 is disposed above the front end of each of the first through holes 34 and the rear end of each of the second through holes 35. The main relay 24 is disposed above the heat pipe 23 in a state where it is attached to the first mounting portion 31 with the relay fixing bolts B4. In other words, the heat pipe 23 is disposed between the main relay 24 and the bottom portion 28.

[0034] The input bus bar 21 and the output bus bar 22 are plates made of conductive metal. The input bus bar 21 is disposed on the rear end side of the electrical junction box 10, which is the current input side. The output bus bar 22 is disposed on the front end side of the electrical junction box 10, which is the current output side.

[0035] As shown in FIG. 3 , the input-side bus bar 21 further includes an input-side main body bus bar 41 and an input-side heat dissipation bus bar 42. Similarly, the output-side bus bar 22 includes an output-side main body bus bar 43 and an output-side heat dissipation bus bar 44. The input-side main body bus bar 41 has a three-dimensional shape due to multiple bending. Specifically, the input-side main body bus bar 41 includes an input-side connection portion 45, a component-side connection portion 46, and a linking portion 47. The input-side connection portion 45 is rectangular in plan view. The input-side connection portion 45 is placed on the upper surface of the input-side first mounting portion 31 and fixed together with the module-side bus bar 17 by first bolts B1. The component-side connection portion 46 is rectangular in side view. The component-side connection portion 46 has a shape extending in the front-rear direction. The front end of the component-side connection portion 46 is connected to a contact portion (not shown) on the input side of the main relay 24. The front-rear intermediate portion of the component-side connecting portion 46 is fixed to the second mounting portion 32 by a second bolt B2 (see FIG. 7).

[0036] The connecting portion 47 has a rectangular shape when viewed from the back or the front. The connecting portion 47 has a shape that extends in the left-right direction so as to cross above each first through hole 34. The connecting portion 47 is disposed between the component-side connecting portion 46 and the input-side connecting portion 45. The lower left end of the connecting portion 47 is connected to the input-side connecting portion 45. The right end of the connecting portion 47 is connected to the component-side connecting portion 46. The input-side connecting portion 45 and the connecting portion 47 form an L-shape when viewed from the side. The component-side connecting portion 46 and the connecting portion 47 form an L-shape when viewed from above.

[0037] The output-side main body bus bar 43 has an output-side connection portion 48, a component-side connection portion 46, and a linking portion 47. The output-side connection portion 48 is fixed to the first mounting portion 31 on the output side. The rest of the configuration is the same as the input-side connection portion 45. The front end of the component-side connection portion 46 of the output-side main body bus bar 43 is connected to a contact portion (not shown) on the output side of the main relay 24. The component-side connection portion 46 of the output-side main body bus bar 43 has a shape that extends longer in the front-rear direction than the component-side connection portion 46 of the input-side main body bus bar 41. The rest of the configuration is the same as the component-side connection portion 46 of the input-side main body bus bar 41. The linking portion 47 of the output-side main body bus bar 43 has a shape that extends in the left-right direction so as to cross above each second through-hole 35. The rest of the configuration is the same as the linking portion 47 of the input-side main body bus bar 41.

[0038] The input-side main body bus bar 41 and the output-side main body bus bar 43 are arranged to surround the periphery of each electronic component 19. Specifically, the input-side main body bus bar 41 and the output-side main body bus bar 43 are arranged to surround each electronic component 19 from three directions, i.e., the front-rear direction and the right direction.

[0039] 5 and 7 , the input-side heat dissipation bus bar 42 has a horizontal portion 49 extending in the left-right direction and a vertical portion 50 extending in the up-down direction. The input-side heat dissipation bus bar 42 is L-shaped when viewed from the front or rear. The horizontal portion 49 is disposed across and above each of the first heat pipes 51 (described later). The horizontal portion 49 faces each of the first heat pipes 51 while being close to them, with an insulating sheet 52 interposed therebetween. The insulating sheet 52 is formed of an insulating portion such as an insulating film or insulating paint.

[0040] The vertical portion 50 is disposed so as to be sandwiched between the component-side connection portion 46 of the input-side main body bus bar 41 and the main relay 24. The vertical portion 50 is connected to the component-side connection portion 46 and the input-side contact portion of the main relay 24 by fastening the third bolt B3.

[0041] The output-side heat dissipation bus bar 44 has the same shape as the input-side heat dissipation bus bar 42. The horizontal portion 49 of the output-side heat dissipation bus bar 44 is disposed so as to cross above each second heat pipe 53 (described later). The vertical portion 50 of the output-side heat dissipation bus bar 44 is disposed so as to be sandwiched between the component-side connection portion 46 of the output-side main body bus bar 43 and the output-side contact portion of the main relay 24.

[0042] (Heat Pipes 23) As shown in Fig. 5, the heat pipes 23 are arranged between the input-side heat dissipation bus bar 42 and the output-side heat dissipation bus bar 44 and the bottom 28. As shown in Fig. 6, each heat pipe 23 is supported by the curved surface portion 37 of each through-hole 33. A plurality of insulating portions 39 are interposed between each heat pipe 23 and the support portion 16. Each insulating portion 39 is fitted into and held in a corresponding recess 38. Each insulating portion 39 is provided individually corresponding to each heat pipe 23. The insulating portions 39 are formed of, for example, an insulating portion such as an insulating sheet or insulating paint.

[0043] In the first embodiment, each heat pipe 23 includes three first heat pipes 51 and three second heat pipes 53. The first heat pipes 51 and the second heat pipes 53 are provided corresponding to the first through holes 34 and the second through holes 35, respectively. Each first heat pipe 51 includes a first heat absorption portion 54 located on the input side of the main relay 24 and a first heat radiation portion 55 located rearward and away from the main relay 24. The first heat absorption portion 54 is located at the front end of the first heat pipe 51. The first heat radiation portion 55 is located at the rear end of the first heat pipe 51.

[0044] Each first heat pipe 51 has a first extension portion 56 extending in the front-to-rear direction between each first heat absorption portion 54 and each first heat radiation portion 55. Similarly, each second heat pipe 53 has a second heat absorption portion 57, a second heat radiation portion 58, and a second extension portion 59. The second heat absorption portion 57 is located on the output side of the main relay 24. The second heat radiation portion 58 is located forward and spaced apart from the main relay 24. The second heat absorption portion 57 is located at the rear end of the second heat pipe 53. The second heat radiation portion 58 is located at the front end of the second heat pipe 53. In the first embodiment, the first heat pipe 51 and the second heat pipe 53 have outer peripheral surfaces with circular cross sections.

[0045] The first heat pipes 51 correspond to the first through holes 34 and are arranged side by side in the left-right direction. Similarly, the second heat pipes 53 correspond to the second through holes 35 and are arranged side by side in the left-right direction. The first heat pipes 51 and the second heat pipes 53 are misaligned in the left-right direction. The first heat absorption portion 54 of the first heat pipe 51 and the second heat absorption portion 57 of the second heat pipe 53 are arranged on the bottom 28, spaced apart in the front-rear direction.

[0046] (Function of Electrical Junction Box 10) Hereinafter, a description will be given of the function of the electrical junction box 10 according to the first embodiment when it is mounted on the vehicle 15. When the electrical junction box 10 is mounted on the vehicle 15, each heat pipe 23 extends in the longitudinal direction of the vehicle 15.

[0047] <When the Electrical Junction Box 10 is Tilt Upward> For example, when the vehicle 15 travels uphill, the electrical junction box 10 is tilted upward. At this time, as shown in FIG. 8 , each heat pipe 23 is tilted upward from the first heat pipe 51 to the second heat pipe 53. That is, the second heat pipe 53 is positioned higher than the first heat pipe 51. Here, the first heat absorption portion 54 is positioned higher than the first heat radiation portion 55. This makes it difficult for the first heat pipe 51 to fully utilize its heat transport capacity. On the other hand, the second heat absorption portion 57 is positioned lower than the second heat radiation portion 58. Therefore, when the electrical junction box 10 is tilted upward, the second heat pipe 53 can fully utilize its heat transport capacity.

[0048] <When the Electrical Junction Box 10 is Tilt Downward at the Front> For example, when the vehicle 15 travels downhill, the electrical junction box 10 is tilted downward at the front. At this time, as shown in FIG. 9 , each heat pipe 23 is tilted downward at the front from the first heat pipe 51 toward the second heat pipe 53. That is, the first heat pipe 51 is positioned higher than the second heat pipe 53. Here, the second heat absorption portion 57 is positioned higher than the second heat radiation portion 58. This makes it difficult for the second heat pipe 53 to fully utilize its heat transport capacity. On the other hand, the first heat absorption portion 54 is positioned lower than the first heat radiation portion 55. Therefore, when the electrical junction box 10 is tilted downward at the front, the first heat pipe 51 can fully utilize its heat transport capacity.

[0049] As described above, whether the electrical junction box 10 is tilted upward or downward, each heat pipe 23 can appropriately exhibit the heat transport capacity of either the first heat pipe 51 or the second heat pipe 53. Thus, according to the first embodiment, the heat pipe 23 can stably exhibit its heat transport capacity.

[0050] <When the electrical junction box 10 is in use> Heat generated in the main relay 24 is transferred to the input-side heat dissipation bus bar 42 and the output-side heat dissipation bus bar 44. The heat transferred to the input-side heat dissipation bus bar 42 is absorbed by the first heat absorption portions 54 of each first heat pipe 51. The heat absorbed by each first heat absorption portion 54 is transferred to each first heat dissipation portion 55 via the internal working fluid of each first heat pipe 51. Furthermore, the heat transferred to each first heat dissipation portion 55 is dissipated to the support portion 16 through each first through-hole 34.

[0051] Similarly, the heat transferred to the output-side heat dissipation bus bar 44 is absorbed by the second heat absorption portions 57 of the second heat pipes 53. The heat absorbed by the second heat absorption portions 57 is transferred to the second heat dissipation portions 58 via the internal working fluid of the second heat pipes 53. Furthermore, the heat transferred to the second heat dissipation portions 58 is dissipated to the support portion 16 through the second through holes 35.

[0052] In particular, in the case of the first embodiment, each heat pipe 23 is supported by the curved surface portion 37 of each through hole 33, so that each heat pipe 23 can be kept close to the support portion 16. Therefore, the first heat dissipation portion 55 and the second heat dissipation portion 58 can efficiently dissipate heat to the support portion 16.

[0053] In addition, in the first embodiment, insulating sheets 52 are provided between each heat pipe 23 and the input-side heat dissipation bus bar 42 and the output-side heat dissipation bus bar 44. This allows each heat pipe 23 to maintain insulation between itself and the input-side heat dissipation bus bar 42 and the output-side heat dissipation bus bar 44. Furthermore, insulating portions 39 are provided between each heat pipe 23 and the support portion 16. This allows each heat pipe 23 to maintain insulation between itself and the support portion 16.

[0054] In the first embodiment, heat generated on the input side of the main relay 24 is conducted to the input-side heat dissipation bus bar 42. Similarly, heat generated on the output side of the main relay 24 is conducted to the output-side heat dissipation bus bar 44. Therefore, the main relay 24 has paths for dissipating heat generated on both the input side and the output side. Therefore, the heat dissipation performance of the main relay 24 can be improved compared to when heat is dissipated from only one of the current input side or output side.

[0055] The heat pipes 23 extend in the longitudinal direction of the vehicle 15. When the vehicle 15 tilts in the longitudinal direction, the heat pipes 23 tilt along with the vehicle 15, allowing either the first heat pipe 51 or the second heat pipe 53 to exhibit a predetermined heat transport capacity. Furthermore, each heat pipe 23 is accommodated within the thickness range of the bottom 28 without occupying a large space. Therefore, the electrical junction box 10 according to the first embodiment can be suitably applied to the vehicle 15.

[0056] [Other Embodiments of the Present Disclosure] The above-described first embodiment disclosed herein should be considered to be illustrative in all respects and not restrictive. In the first embodiment, the heat pipe is composed of a first heat pipe and a second heat pipe, which are separate from each other. However, in other embodiments, the heat pipe may be an integrated pipe extending continuously on both the front and rear sides of the heat-generating component. For example, the heat pipe may have a solid portion (partition portion) in the front-rear middle, with a first heat absorption portion and a second heat absorption portion on both the front and rear sides of the solid portion. In the first embodiment, the heat pipe is entirely housed in the case. However, in other embodiments, the heat pipe may partially protrude from the case. In the first embodiment, the case of the electrical junction box is composed of a lower case. However, in other embodiments, the case of the electrical junction box may include an upper case (upper cover) in addition to the lower case. In the first embodiment, only the lower half of the heat pipe is housed in the through-hole. However, in other embodiments, the entire heat pipe may be housed in the through-hole. In the first embodiment, the heat pipe and the support portion are disposed adjacent to each other with an insulating portion interposed therebetween. In contrast, in other embodiments, the heat pipe and the support portion may be in contact with each other. In the first embodiment, the electrical junction box is applied to a battery pack. In contrast, in other embodiments, the electrical junction box can be widely applied to parts other than battery packs. In the first embodiment, insulating sheets are disposed between the input-side and output-side heat dissipation bus bars and the heat pipe. In contrast, in other embodiments, insulating paint may be disposed between the input-side and output-side heat dissipation bus bars and the heat pipe.

[0057] DESCRIPTION OF SYMBOLS 10...Electrical junction box 11...Battery pack 12...Battery module 13...Housing 14...Connector 15...Vehicle 16...Support portion 17...Module side bus bar 18...Connector side bus bar 19...Electronic component 20...Case 21...Input side bus bar 22...Output side bus bar 23...Heat pipe 24...Main relay 25...Relay 26...Resistor 27...Heat-generating component 28...Bottom 29...Side 30...Mounting portion 31...First mounting portion 32...Second mounting portion 33...Through hole 34...First through hole 35...Second through hole 36...Edge portion 37...Curved portion 38...Concave portion 39...Insulating portion 40...Convex portion 41...Input side main body bus bar 42...Input side heat dissipation bus bar 43...Output side main body bus bar 44...Output side heat dissipation bus bar 45...Input side connection portion 46...Component side connection portion 47...Coupling portion 48...Output side connection portion 49...Horizontal portion 50...Vertical portion 51...First heat pipe 52...Insulating sheet 53...Second heat pipe 54...First heat absorption portion 55...First heat dissipation portion 56...First extension portion 57...Second heat absorption portion 58...Second heat dissipation portion 59...Second extension portion 60...Inter-module bus bar B1...First bolt B2...Second bolt B3...Third bolt B4...Relay fixing bolt

Claims

1. An electrical connection box comprising a case, a heat-generating component housed in the case, and a heat pipe arranged in the case, wherein the heat pipe has a heat absorption portion located on the side of the heat-generating component and a heat dissipation portion located away from the heat-generating component, and further wherein the heat pipe has a first extension portion and a second extension portion extending in opposite directions from the heat absorption portion to the heat dissipation portion.

2. An electrical junction box as claimed in claim 1, wherein the case has a bottom, the bottom is provided with a through hole, the heat pipe is supported by the bottom, and the through hole in the bottom is positioned between the heat pipe and a metal support that supports the bottom.

3. The electrical junction box according to claim 2, wherein the heat pipe is disposed inside the through hole in the bottom portion.

4. The electrical junction box according to claim 3, further comprising an insulating portion disposed between said heat pipe and said support portion.

5. An electrical connection box as described in claim 1, wherein the heat pipe comprises a first heat pipe having the first extension portion and a second heat pipe having the second extension portion, the first heat pipe having a first heat absorption portion as the heat absorption portion, and the second heat pipe having a second heat absorption portion separate from the first heat absorption portion as the heat absorption portion.

6. The electrical connection box according to claim 5, wherein the heat-generating component has a relay and a bus bar connected to the relay, the bus bar has an input-side heat dissipation bus bar which is the input side of current, and an output-side heat dissipation bus bar which is the output side of current, the input-side heat dissipation bus bar being arranged in contact with or facing the first heat pipe, and the output-side heat dissipation bus bar being arranged in contact with or facing the second heat pipe.

7. An electrical connection box as described in any one of claims 1 to 6, wherein when the electrical connection box is mounted on a vehicle, the heat pipe is shaped to extend in the fore-and-aft direction of the vehicle.

Images