Electrical junction box

Abstract

An electrical junction box 1 is connected to an external bus bar 2, and comprises: an electronic component that generates heat by energization; and a heat radiation member 30. The electronic component has a terminal part 22 connected to the external bus bar 2. The heat radiation member 30 includes: a superposition part 31 disposed so as to overlap the terminal part 22 in a first direction; and an expansion part 32 disposed so as to protrude to the outside from the terminal part 22 in a first direction view. The external bus bar 2, the terminal part 22, and the heat radiation member 30 are collectively fastened by a bolt B1.

Description

Electrical junction box

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

[0002] An electrical junction box described in Japanese Patent Laid-Open No. 2022-191739 (hereinafter referred to as Patent Document 1) is known. The electrical junction box described in Patent Document 1 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and distributes power supplied from a battery to various devices. The electrical junction box includes a bus bar electrically connected to the battery and a fuse directly connected to the bus bar.

[0003] Japanese Patent Application Laid-Open No. 2022-191739

[0004] In the above configuration, the bus bar is elongated in the front-to-rear direction and has a large surface area. This allows heat generated by the fuse to be transferred to the bus bar and then efficiently dissipated from the bus bar to the lower case and the outside air. However, in the above configuration, the long bus bar may increase the weight of the electrical junction box.

[0005] The electrical connection box of the present disclosure is an electrical connection box connected to an external bus bar, and includes an electronic component that generates heat when current is applied, and a heat dissipation member, wherein the electronic component has a terminal portion connected to the external bus bar, and the heat dissipation member includes an overlapping portion that is arranged overlapping with the terminal portion in a first direction, and an extension portion that is arranged protruding outside the terminal portion when viewed in the first direction, and the external bus bar, the terminal portion, and the heat dissipation member are fastened together with bolts.

[0006] According to the present disclosure, it is possible to provide a lightweight electrical junction box capable of dissipating heat from electronic components.

[0007] FIG. 1 is an exploded perspective view of an electrical junction box according to the first embodiment. FIG. 2 is a plan view of the electrical junction box according to the first embodiment. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a plan view of the electrical junction box according to the first embodiment, excluding an upper case. FIG. 5 is an exploded perspective view of the electrical junction box according to the first embodiment, excluding an upper case. FIG. 6 is a bottom view of a heat dissipation member and a fuse according to the first embodiment. FIG. 7 is a perspective view of a heat dissipation member according to a modified example of the first embodiment. FIG. 8 is a plan view of an electrical junction box according to a second embodiment. FIG. 9 is a cross-sectional view taken along line B-B in FIG. 8. FIG. 10 is a cross-sectional view taken along line C-C in FIG. 8. FIG. 11 is an exploded perspective view of an electrical junction box according to the second embodiment. FIG. 12 is a plan view of a heat dissipation member and a fuse according to the second embodiment. FIG. 13 is a perspective view of a heat dissipation member and a fuse according to the second embodiment. FIG. 14 is a perspective view of a heat dissipation member and a fuse according to a modified example of the second embodiment.

[0008] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. [1] An electrical junction box of the present disclosure is an electrical junction box connected to an external bus bar, comprising: an electronic component that generates heat when current is applied; and a heat dissipation member; the electronic component has a terminal portion connected to the external bus bar; the heat dissipation member comprises an overlapping portion that is arranged overlapping with the terminal portion in a first direction and an extension portion that is arranged protruding outside the terminal portion as viewed in the first direction; and the external bus bar, the terminal portion, and the heat dissipation member are fastened together with a bolt.

[0009] With this configuration, the heat generated by the electronic components can be dissipated to the outside by the extension of the heat dissipation member. Also, since there is no need to provide a long bus bar between the external bus bar and the electronic components to cool the electronic components, the weight of the electrical junction box can be reduced.

[0010] [2] In the above [1], it is preferable that the extension portion is plate-shaped, and the area of ​​the extension portion as viewed in the thickness direction of the extension portion is larger than the area of ​​the terminal portion as viewed in the first direction.

[0011] With this configuration, it becomes easier to improve the heat dissipation efficiency of the extension portion.

[0012] [3] In the above [1] or [2], the heat dissipation member is preferably made of metal.

[0013] With this configuration, the thermal conductivity and strength of the heat dissipation member can be easily increased.

[0014] [4] It is preferable that the electrical connection box of any one of [1] to [3] above further comprises a case in which the electronic components are held, and the heat dissipation member is arranged in close proximity to the case.

[0015] With this configuration, heat can be easily dissipated from the heat dissipation member to the outside via the case.

[0016] [5] In the above [4], it is preferable that the case comprises a lower case and an upper case arranged above the lower case, the heat dissipation member is arranged in the lower case, and the extension portion has a portion extending in a direction perpendicular to the first direction.

[0017] With this configuration, the portion of the extension portion that is disposed adjacent to the lower case is enlarged, which facilitates heat transfer from the extension portion to the lower case. Also, the height of the electrical junction box can be reduced.

[0018] [6] In the above [4], it is preferable that the case comprises a lower case and an upper case arranged above the lower case, the heat dissipation member is arranged in the upper case, and the extension portion has a portion extending in the first direction.

[0019] With this configuration, for example, if the electrical junction box is positioned so that the upper case is located above the lower case, the rising air current around the extension portion makes it easier to transfer heat from the extension portion to the upper case.

[0020] [7] In any one of the above [1] to [6], it is preferable that the overlapping portion is not disposed between the terminal portion and the external bus bar.

[0021] With this configuration, the contact resistance between the terminal portion and the external bus bar can be reduced compared to when the overlapping portion is disposed between the terminal portion and the external bus bar.

[0022] [8] It is preferable that the electrical connection box of any one of [1] to [7] above is an electrical connection box connected to a detection circuit, the detection circuit detects the state of a battery electrically connected to the external bus bar, and the heat dissipation member has a connection part connected to the detection circuit.

[0023] With this configuration, there is no need to provide a new member for connecting the detection circuit and the external bus bar.

[0024] [9] In any one of the above [1] to [8], it is preferable that at least a portion of the heat dissipation member is covered with a coating material, and that the coating material has a higher emissivity than the heat dissipation member.

[0025] With this configuration, heat can be easily dissipated to the outside by radiation from the heat dissipation member.

[0026]

[10] In any one of the above [1] to [9], it is preferable that the heat dissipation member is plate-shaped and the thickness of the heat dissipation member is smaller than the thickness of the external bus bar.

[0027] This configuration makes it easier to reduce the weight of the electrical junction box.

[0028] [Details of the Embodiments of the Present Disclosure] The following describes embodiments of the present disclosure. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. In the drawings, for the convenience of explanation, some components may be exaggerated or simplified. Furthermore, the dimensional ratios of each part may differ between drawings. In this specification, "orthogonal" does not only refer to a strict orthogonal relationship, but also includes a roughly orthogonal relationship within the scope of the operation and effect of this embodiment.

[0029] In addition, "facing" in this specification refers to surfaces or components facing each other, and includes not only cases where they are completely facing each other, but also cases where they are partially facing each other. In addition, "facing" in this specification includes both cases where a component separate from the two components is interposed between the two components, and cases where nothing is interposed between the two components.

[0030] First Embodiment A first embodiment of the present disclosure will be described with reference to Figures 1 to 7. In the following description, the direction indicated by arrow Z is defined as upward, the direction indicated by arrow X as forward, and the direction indicated by arrow Y as leftward. Note that, for multiple identical components, only some of the components may be designated by reference numerals, and the reference numerals for the other components may be omitted.

[0031] (Electrical Junction Box 1) The electrical junction box 1 of this embodiment is mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and is disposed in a power supply path from a battery to a load such as a motor. As shown in FIG. 2 , the electrical junction box 1 is connected to external bus bars 2 and 3. The external bus bars 2 and 3 are used to electrically connect the electrical junction box 1 to devices (including a battery) provided outside the electrical junction box 1. The external bus bars 2 and 3 have portions disposed outside the electrical junction box 1. The external bus bar 2 is electrically connected to a battery. The external bus bar 3 is electrically connected to a load. The external bus bars 2 and 3 are connected to the electrical junction box 1 by bolt fastening. As shown in FIG. 1 , the electrical junction box 1 includes a case 10, a fuse 20 (an example of an electronic component), a heat dissipation member 30, a first bus bar 41, a second bus bar 42, a third bus bar 43, and relays 50 and 60.

[0032] (Case 10) The case 10 is made of synthetic resin and includes a lower case 11 and an upper case 12. The upper case 12 is assembled to and stacked on the lower case 11. When bolts B1, B3 are fastened from above to connect the external bus bars 2, 3 and the electrical junction box 1 by bolt fastening, the upper case 12 is arranged above the lower case 11, as shown in Figures 1 to 3. Below, the configuration and arrangement of each component of the electrical junction box 1 will be described assuming that the upper case 12 is arranged above the lower case 11.

[0033] (Lower Case 11) As shown in Figures 4 and 5, the lower case 11 is formed in the shape of a tray that is elongated in the front-to-rear direction. The fuse 20, the heat dissipation member 30, the first bus bar 41, the second bus bar 42, the third bus bar 43, and the relay 50 are arranged in the lower case 11. As shown in Figure 5, a fuse mounting section 11A in which the fuse 20 is mounted is formed in the front portion of the lower case 11. The fuse mounting section 11A is a recess capable of accommodating the main body 21 of the fuse 20. As shown in Figures 3 and 5, fastening sections N1 and N2 are provided on both the front and rear sides of the fuse mounting section 11A, to which bolts B1 and B2 can be fastened, respectively. A horizontally extending opposing surface 11B is formed in front of the fuse mounting section 11A. The opposing surface 11B is a surface that faces the heat dissipation member 30 in the vertical direction. As shown in Fig. 5, the rear portion of the lower case 11 is formed with a mounting surface 11C on which the relay 50 is mounted and a positioning portion 11D for positioning the relay 50. The positioning portion 11D is a recess recessed from a side wall portion 11E that rises upward from the right edge of the mounting surface 11C. The rear end of the lower case 11 is provided with a fastening portion N3 to which a bolt B3 can be fastened. Note that the mounting surface 11C of the lower case 11 may further be provided with a fixing portion (not shown) for fixing the relay 50.

[0034] (Upper Case 12) As shown in FIG. 1 , the upper case 12 is lid-shaped. The upper case 12 includes a first busbar accommodating portion 12A that accommodates the first busbar 41, a second busbar accommodating portion 12B that accommodates the second busbar 42, and a third busbar accommodating portion 12C that accommodates the third busbar 43. Each of the busbar accommodating portions 12A, 12B, and 12C has a groove shape that fits the shape of each of the busbars 41, 42, and 43. A window portion 12D is provided at the front end of the upper case 12 for connecting the terminal portion 22 of the fuse 20 to the external busbar 2. As shown in FIGS. 1 and 3 , a facing portion 12E that faces the heat dissipation member 30 in the vertical direction is formed in front of the window portion 12D. The facing portion 12E has a plate shape that extends horizontally.

[0035] 1 , the upper case 12 may have a relay mounting portion 12F in which the relay 60 is mounted. The relay mounting portion 12F is formed by utilizing the space between the second bus bar 42 and the third bus bar 43, for example.

[0036] (Fuse 20) As shown in Figure 5, the fuse 20 includes a main body 21 and two terminals 22 extending from both the front and rear ends of the main body 21. The main body 21 is block-shaped. The terminals 22 are made of metal. The terminals 22 are thin plates extending in the vertical direction. The terminals 22 have insertion holes 22A through which the bolts B1 and B2 are inserted.

[0037] The relay 50 is a large mechanical relay that receives a high current from a battery. The relay 50 includes a main body 51 and a partition wall 52 extending from the right surface of the main body 51. The main body 51 is block-shaped. As shown in FIG. 4 , the partition wall 52 engages with a positioning portion 11D of the lower case 11, thereby positioning the relay 50 relative to the lower case 11. Two nut-shaped terminals (not shown) are formed on the right surface of the main body 51, and bolts B4 and B5 can be fastened to these terminals. The two terminals of the relay 50 are disposed across the partition wall 52.

[0038] 5 , the first bus bar 41, the second bus bar 42, and the third bus bar 43 are each formed by stamping and bending a metal plate. The metal plate forming the second bus bar 42 and the third bus bar 43 is thinner than the metal plate forming the first bus bar 41. The first bus bar 41 includes a relay connection portion 41A connected to a terminal portion of the relay 50, and an external connection portion 41B connected to the external bus bar 3. The relay connection portion 41A has an insertion hole 41A1 through which a bolt B4 is inserted. The external connection portion 41B has an insertion hole 41B1 through which a bolt B3 is inserted.

[0039] The second bus bar 42 includes a fuse connection portion 42A connected to the terminal portion 22 of the fuse 20, a relay connection portion 42B connected to the terminal portion of the relay 50, an intermediate portion 42C connecting the fuse connection portion 42A and the relay connection portion 42B, and an extension portion 42D extending from the intermediate portion 42C forward of the fuse connection portion 42A. The fuse connection portion 42A and the relay connection portion 42B have insertion holes 42A1 and 42B1 through which bolts B2 and B5 are inserted, respectively. The fuse connection portion 42A extends leftward from the front end of the intermediate portion 42C. The intermediate portion 42C has a plate shape extending in the front-to-rear direction. The extension portion 42D is positioned to utilize the space to the right of the fuse 20 and has the function of dissipating heat transferred from the fuse 20 and the relay 50 to the second bus bar 42 to the case 10.

[0040] The third bus bar 43 includes a fuse connection portion 43A connected to the terminal portion 22 of the fuse 20, a relay connection portion 43B connected to the terminal portion of the relay 50, a bent portion 43C connecting the fuse connection portion 43A and the relay connection portion 43B, and an extension portion 43D extending forward from the bent portion 43C beyond the fuse connection portion 43A. The fuse connection portion 43A and the relay connection portion 43B are arranged to overlap with the fuse connection portion 42A and the relay connection portion 42B, respectively. The fuse connection portion 43A and the relay connection portion 43B have insertion holes 43A1 and 43B1 through which bolts B2 and B5 are inserted, respectively. The fuse connection portion 43A extends rightward from the front end of the bent portion 43C. The bent portion 43C is formed by bending a metal plate. The extension 43D is arranged to utilize the space to the left of the fuse 20 and has the function of dissipating heat transferred from the fuse 20 and the relay 50 to the third bus bar 43 to the case 10.

[0041] As described above, the second bus bar 42 and the third bus bar 43 are both components that form the conductive path between the fuse 20 and the relay 50, but they are arranged so as to branch off from each other with a space between them. This, unlike the present embodiment, allows the surface area of ​​the bus bars connecting the fuse 20 and the relay 50 (i.e., the second bus bar 42 and the third bus bar 43) to be larger than when the fuse 20 and the relay 50 are connected by a single bus bar. This allows the fuse 20 and the relay 50 to dissipate heat efficiently. Furthermore, by making the thickness of the second bus bar 42 and the third bus bar 43 approximately half the thickness of the first bus bar 41, for example, the heat dissipation efficiency of the fuse 20 and the relay 50 can be improved while suppressing an increase in the weight of the electrical junction box 1.

[0042] (Heat Dissipation Member 30) The heat dissipation member 30 has a plate shape. In this embodiment, the heat dissipation member 30 is made of a metal such as copper, a copper alloy, aluminum, or an aluminum alloy. As shown in FIG. 6 , the heat dissipation member 30 includes an overlapping portion 31 that overlaps the terminal portion 22 in the vertical direction (an example of a first direction) and an extension portion 32 that extends outside the terminal portion 22 when viewed from the vertical direction. The area of ​​the extension portion 32 when viewed from the thickness direction (vertical direction) of the extension portion 32 is, for example, larger than the area of ​​the terminal portion 22 when viewed from the vertical direction. Note that the area of ​​the extension portion 32 when viewed from the thickness direction (vertical direction) of the extension portion 32 may be equal to or smaller than the area of ​​the terminal portion 22 when viewed from the vertical direction. The overlapping portion 31 has a through hole 31A through which a bolt B1 is inserted. As shown in FIG. 3, the external bus bar 2, the terminal portion 22, and the heat dissipation member 30 are fastened together by a bolt B1.

[0043] Because the heat dissipation member 30 has the extension portion 32 extending beyond the terminal portion 22, the surface area of ​​the portion connected to the terminal portion 22 and capable of dissipating heat from the terminal portion 22 can be increased compared to when the heat dissipation member 30 is not provided. This makes it easier to dissipate heat generated by the fuse 20 to the outside. Furthermore, even when the thickness of the heat dissipation member 30 is thin, the surface area of ​​the heat dissipation member 30 can be increased by increasing the dimension of the extension portion 32 in a direction perpendicular to the thickness direction. Therefore, compared to when a long bus bar is provided between the external bus bar 2 and the fuse 20, for example, the weight of the electrical junction box 1 can be reduced while the heat dissipation efficiency of the fuse 20 can be improved.

[0044] 3 , the overlapping portion 31 is disposed below the terminal portion 22. The external bus bar 2 is bolted to the terminal portion 22 in a state where it is overlapped above the terminal portion 22. In other words, the overlapping portion 31 is not disposed between the external bus bar 2 and the terminal portion 22. This allows for a reduction in contact resistance between the external bus bar 2 and the terminal portion 22 compared to when the overlapping portion is disposed between the external bus bar 2 and the terminal portion 22.

[0045] The heat dissipation member 30 is disposed in close proximity to the case 10. Specifically, the distance between the heat dissipation member 30 and the case 10 in the thickness direction (vertical direction) of the heat dissipation member 30 is preferably 5 mm or less, and more preferably 2 mm or less. It is most preferable that the heat dissipation member 30 and the case 10 are in contact with each other in the thickness direction (vertical direction) of the heat dissipation member 30. By disposing the heat dissipation member 30 and the case 10 in close proximity, heat can be more easily dissipated from the heat dissipation member 30 to the outside via the case 10.

[0046] As shown in Fig. 3, the extension portion 32 has a plate shape extending in the horizontal direction (an example of a direction perpendicular to the first direction). The extension portion 32 is disposed adjacent to the opposing surface 11B of the lower case 11. The extension portion 32 faces the opposing surface 11B in the vertical direction. The extension portion 32 is also disposed adjacent to the opposing portion 12E of the upper case 12. The extension portion 32 faces the opposing portion 12E in the vertical direction. This facilitates heat dissipation from the extension portion 32 to the lower case 11 and the upper case 12.

[0047] As shown in FIG. 7 , the heat dissipation member 30 of this embodiment may include a connection portion 33 connected to a detection circuit (not shown). Here, the detection circuit has a function of detecting the state of the battery. For example, the detection circuit has a function of detecting voltage or a function of detecting leakage current. The connection portion 33 may be, for example, in the form of a tab extending from a portion of the heat dissipation member 30 near the overlapping portion 31. By providing the connection portion 33 on the heat dissipation member 30, it is not necessary to provide a new member for connecting the detection circuit and the external bus bar 2.

[0048] (Action and effect of embodiment 1) (1-1) The electrical connection box 1 of embodiment 1 is an electrical connection box 1 connected to an external bus bar 2, and includes an electronic component (fuse 20) that generates heat when current is applied, and a heat dissipation member 30, the electronic component having a terminal portion 22 connected to the external bus bar 2, the heat dissipation member 30 including an overlapping portion 31 arranged overlapping with the terminal portion 22 in a first direction (vertical direction), and an extension portion 32 arranged to extend outside the terminal portion 22 when viewed in the first direction, and the external bus bar 2, the terminal portion 22, and the heat dissipation member 30 are fastened together by a bolt B1.

[0049] With this configuration, heat generated by the electronic components can be dissipated to the outside by the extension portion 32 of the heat dissipation member 30. Furthermore, since it is not necessary to provide a long bus bar between the external bus bar 2 and the electronic components in order to cool the electronic components, it is easy to reduce the weight of the electrical junction box 1.

[0050] (1-2) In the first embodiment, the extension portion 32 is plate-shaped, and the area of ​​the extension portion 32 as viewed in the thickness direction of the extension portion 32 is larger than the area of ​​the terminal portion 22 as viewed in the first direction.

[0051] With this configuration, the heat dissipation efficiency of the extension portion 32 can be easily improved.

[0052] (1-3) In the first embodiment, the heat dissipation member 30 is made of metal.

[0053] With this configuration, the thermal conductivity and strength of the heat dissipation member 30 can be easily increased.

[0054] (1-4) The electrical junction box 1 according to the first embodiment further includes a case 10 that holds electronic components, and the heat dissipation member 30 is disposed adjacent to the case 10 .

[0055] With this configuration, heat can be easily dissipated from the heat dissipation member 30 to the outside via the case 10 .

[0056] (1-5) In embodiment 1, the case 10 comprises a lower case 11 and an upper case 12 arranged above the lower case 11, the heat dissipation member 30 is arranged in the lower case 11, and the extension portion 32 has a portion extending in a direction (horizontal direction) perpendicular to the first direction.

[0057] With this configuration, the portion of the extension portion 32 that is disposed in close proximity to the lower case 11 is enlarged, which facilitates heat transfer from the extension portion 32 to the lower case 11. In addition, the height of the electrical junction box 1 can be reduced.

[0058] (1-6) In the first embodiment, the overlapping portion 31 is not disposed between the terminal portion 22 and the external bus bar 2 .

[0059] With this configuration, the contact resistance between the terminal portion 22 and the external bus bar 2 can be reduced compared to when the overlapping portion 31 is disposed between the terminal portion 22 and the external bus bar 2 .

[0060] (1-7) The electrical connection box 1 of embodiment 1 is an electrical connection box 1 connected to a detection circuit, and the detection circuit detects the state of a battery electrically connected to the external bus bar 2, and the heat dissipation member 30 may have a connection portion 33 connected to the detection circuit.

[0061] With this configuration, there is no need to provide a new member for connecting the detection circuit and the external bus bar 2 .

[0062] (1-8) In the first embodiment, the heat dissipation member 30 is plate-shaped, and the thickness of the heat dissipation member 30 is smaller than the thickness of the external bus bar 2 .

[0063] With this configuration, the weight of the electrical junction box 1 can be reduced.

[0064] Second Embodiment A second embodiment of the present disclosure will be described with reference to Fig. 8 to Fig. 14. The electrical junction box 101 according to the second embodiment is configured substantially similarly to the first embodiment except for the configuration of the heat dissipation member 130 and the configuration of the components around the heat dissipation member 130, and therefore, descriptions of the same components, actions, and effects as those of the first embodiment may be omitted.

[0065] (Electrical junction box 101) As shown in Figure 11, the electrical junction box 101 includes a case 110, a fuse 20, a heat dissipation member 130, a first bus bar 41, a second bus bar 42, a third bus bar 43, and relays 50 and 60.

[0066] (Case 110, Upper Case 112) The case 110 includes a lower case 11 and an upper case 112. The upper case 112 does not have the window portion 12D and the opposing portion 12E of the first embodiment. The front end of the upper case 112 is formed with a placement portion 112G in which the heat dissipation member 130 is placed.

[0067] 12 and 13 , the heat dissipation member 130 is formed by bending a metal plate. The heat dissipation member 130 includes an overlapping portion 31 similar to that of the first embodiment, and an extension portion 132 that extends beyond the terminal portion 22 when viewed from the top-bottom direction. In this embodiment, the extension portion 132 includes a first extension portion 132A that extends horizontally continuous with the overlapping portion 31, and two second extension portions 132B that extend upward from both left and right edges of the first extension portion 132A.

[0068] As shown in FIG. 10 , the arrangement section 112G of the upper case 112 is recessed to accommodate two second extension sections 132B. The second extension section 132B is disposed adjacent to the arrangement section 112G. The second extension section 132B faces the arrangement section 112G in the left-right direction. The second extension section 132B and the arrangement section 112G are disposed with a small gap between them in the left-right direction. This configuration facilitates heat dissipation from the second extension section 132B to the arrangement section 112G. Because the second extension section 132B extends in the vertical direction, the rising air current around the second extension section 132B facilitates more efficient heat transfer from the second extension section 132B to the arrangement section 112G. Note that the second extension section 132B and the arrangement section 112G may be disposed in close contact with each other.

[0069] The heat dissipation member 130 may be, for example, insert-molded into the upper case 112. Alternatively, the heat dissipation member 130 may be held in the upper case 112 by having a locking structure (not shown) that locks the heat dissipation member 130 and the upper case 112 together in the vertical direction. Alternatively, the heat dissipation member 130 may be press-fitted into the upper case 112.

[0070] 8 and 11 , when the heat dissipation member 130 is placed in the placement portion 112G, the horizontally extending portions of the heat dissipation member 130 (the overlapping portion 31 and the first extension portion 132A) are exposed upward. As shown in Fig. 9 , the overlapping portion 31 of the heat dissipation member 130 is placed above the terminal portions 22. The external bus bar 2 is bolted to the terminal portions 22 in a state where it is placed above the overlapping portion 31 of the heat dissipation member 130. In other words, the overlapping portion 31 of the heat dissipation member 130 is placed between the terminal portions 22 and the external bus bar 2.

[0071] (Coating Material 134) The first extension portion 132A and the opposing surface 11B of the lower case 11 are disposed with a larger gap therebetween than in the first embodiment. This makes it difficult for heat to be transferred from the first extension portion 132A to the lower case 11. Therefore, as shown in FIG. 14 , the underside of the first extension portion 132A may be coated with a coating material 134 having a higher emissivity than the heat dissipation member 130. For example, the coating material 134 may be an insulating resin material such as polyimide, fluororesin, or epoxy resin. With this configuration, even when the first extension portion 132A and the opposing surface 11B are spaced apart, as shown in FIG. 9 , heat is more likely to be released to the outside from the first extension portion 132A by radiation.

[0072] The covering material 134 is preferably formed on a portion of the extension portion 132 that is exposed to the outside air. The covering material 134 is preferably not provided on a portion of the extension portion 132 that is in contact with the external bus bar 2 or the terminal portion 22.

[0073] (Action and effect of embodiment 2) (2-1) In embodiment 2, the case 110 comprises a lower case 11 and an upper case 112 arranged above the lower case 11, the heat dissipation member 130 is arranged in the upper case 112, and the extension portion 132 has a portion (second extension portion 132B) extending in the first direction (up and down direction).

[0074] With this configuration, for example, when the electrical connection box 101 is positioned so that the upper case 112 is located above the lower case 11, the rising air current around the extension portion 132 makes it easier to transfer heat from the extension portion 132 to the upper case 112.

[0075] (2-2) In the second embodiment, at least a portion of the heat dissipation member 130 is covered with a covering material 134 , and the covering material 134 may have a higher emissivity than the heat dissipation member 130 .

[0076] With this configuration, heat can be easily dissipated to the outside by radiation from the heat dissipation member 130 .

[0077] Other Embodiments The above-described first and second embodiments can be modified as follows: The above-described first and second embodiments and the following modifications can be combined and implemented within the scope of technical compatibility.

[0078] In the first and second embodiments, the fuse 20 is used as an example of an electronic component, but the electronic component does not have to be a fuse as long as it has the property of generating heat when current is applied. The electronic component may be, for example, a relay, a resistor, a coil, a capacitor, a diode, an integrated circuit (IC), a switching element such as a field effect transistor (FET), or the like.

[0079] In the first and second embodiments, the heat dissipation members 30 and 130 are made of metal. However, the heat dissipation members may be made of a material other than metal.

[0080] In the above-described first and second embodiments, the external bus bar 2 fastened together with the heat dissipation members 30, 130 and the terminal portions 22 was electrically connected to the battery, but the external bus bar fastened together with the heat dissipation members and the terminal portions may be electrically connected to a configuration other than the battery (for example, a load).

[0081] 1: Electrical junction box 2, 3: External bus bar 10: Case 11: Lower case 11A: Fuse placement section 11B: Opposing surface 11C: Mounting surface 11D: Positioning section 11E: Side wall section 12: Upper case 12A: First bus bar accommodating section 12B: Second bus bar accommodating section 12C: Third bus bar accommodating section 12D: Window section 12E: Opposing section 12F: Relay placement section 20: Fuse 21: Main body section 22: Terminal section 22A: Insertion hole 30: Heat dissipation member 31: Overlapping section 31A: Through hole 32: Extension section 33: Connection section 41: First bus bar 41A: Relay connection section 41A1: Insertion hole 41B: External connection section 41B1: Insertion hole 42: Second bus bar 42A: Fuse connection section 42A1: Insertion hole 42B: Relay connection portion 42B1: Insertion hole 42C: Middle portion 42D: Extension portion 43: Third bus bar 43A: Fuse connection portion 43A1: Insertion hole 43B: Relay connection portion 43B1: Insertion hole 43C: Bent portion 43D: Extension portion 50: Relay 51: Main body portion 52: Partition wall 60: Relay 101: Electrical connection box 110: Case 112: Upper case 112G: Arrangement portion 130: Heat dissipation member 132: Extension portion 132A: First extension portion 132B: Second extension portion 134: Coating material B1, B2, B3, B4, B5: Bolts N1, N2, N3: Fastening portion

Claims

1. An electrical connection box connected to an external bus bar, comprising: an electronic component that generates heat when current is passed through it; and a heat dissipation member, wherein the electronic component has a terminal portion connected to the external bus bar, and the heat dissipation member has an overlapping portion arranged overlapping the terminal portion in a first direction, and an extension portion arranged to extend outside the terminal portion when viewed in the first direction, and the external bus bar, the terminal portion, and the heat dissipation member are fastened together with bolts.

2. An electrical connection box as described in claim 1, wherein the extension portion is plate-shaped, and the area of ​​the extension portion as viewed in the thickness direction of the extension portion is larger than the area of ​​the terminal portion as viewed in the first direction.

3. The electrical junction box according to claim 1 or 2, wherein the heat dissipation member is made of metal.

4. The electrical connection box according to claim 1 or 2, further comprising a case for holding the electronic components, the heat dissipation member being disposed adjacent to the case.

5. An electrical connection box as described in claim 4, wherein the case comprises a lower case and an upper case arranged above the lower case, the heat dissipation member is arranged in the lower case, and the extension portion has a portion extending in a direction perpendicular to the first direction.

6. An electrical connection box as described in claim 4, wherein the case comprises a lower case and an upper case disposed above the lower case, the heat dissipation member is disposed in the upper case, and the extension portion has a portion extending in the first direction.

7. The electrical connection box according to claim 1 or 2, wherein the overlapping portion is not disposed between the terminal portion and the external bus bar.

8. An electrical connection box as described in claim 1 or claim 2, which is connected to a detection circuit, the detection circuit detects the state of a battery electrically connected to the external bus bar, and the heat dissipation member has a connection portion connected to the detection circuit.

9. An electrical junction box according to claim 1 or 2, wherein at least a portion of said heat dissipation member is covered with a covering material, and said covering material has a higher emissivity than said heat dissipation member.

10. The electrical junction box according to claim 1 or 2, wherein the heat dissipation member is plate-shaped, and the thickness of the heat dissipation member is smaller than the thickness of the external bus bar.

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