Electric connection box

Abstract

To provide an electric connection box that enables a reduction in amount of heat dissipation gap filler used.SOLUTION: An electric connection box 11 includes: a resin base member 12 having a through hole 12a penetrating downward Z2; a first bus bar 13 arranged above Z1 the base member 12 at a position corresponding to the through hole 12a; a second bus bar 14 arranged above Z1 the first bus bar 13; and a bolt 15 and a nut 16 fastening the first bus bar 13 and the second bus bar 14 together at a position corresponding to the through hole 12a. The electric connection box is arranged above Z1 a heat dissipation member 21, and a lower surface 13b of the first bus bar 13 exposed from the through hole 12a is connected to the heat dissipation member 21 via a heat dissipation gap filler 22. The first bus bar 13 has an accommodating portion 15c that accommodates a head 15a of the bolt 15.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, an electrical connection box includes a resin base member, a first bus bar, a second bus bar, bolts and nuts. The base member has a through hole penetrating downward. The first bus bar is disposed above the base member at a position corresponding to the through hole. The second bus bar is disposed above the first bus bar and overlapped therewith. The bolts and nuts fasten the first bus bar and the second bus bar at a position corresponding to the through hole. Since the electrical connection box through which a large current flows is prone to heat generation, the heat dissipation may be improved by connecting the electrical connection box to a heat dissipation member made of aluminum or the like. In such a case, for example, it has been considered to connect the lower surface of the first bus bar exposed from the through hole to the heat dissipation member via a heat dissipation gap filler such as silicone grease described in Patent Document 1. In this way, the heat dissipation can be improved while ensuring insulation between the first bus bar and the heat dissipation member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-101493 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned electrical connection box, the heads of the bolts or nuts protrude significantly from the lower surface of the first bus bar. Therefore, in order to ensure the insulation between the first bus bar and the heat dissipation member, it is necessary to ensure a large gap between the lower surface of the first bus bar and the heat dissipation member. This causes a problem that the amount of heat dissipation gap filler interposed between the lower surface of the first bus bar and the heat dissipation member increases.

[0005] An object of the present disclosure is to provide an electrical junction box that enables a reduction in the amount of heat dissipation gap filler used. [Means for solving the problem]

[0006] The electrical junction box disclosed herein comprises a resin base member having a through hole penetrating downward, a first bus bar arranged above the base member at a position corresponding to the through hole, a second bus bar arranged stacked above the first bus bar, and bolts and nuts that fasten the first bus bar and the second bus bar at a position corresponding to the through hole, the electrical junction box being arranged above a heat dissipation member, with the underside of the first bus bar exposed from the through hole being connected to the heat dissipation member via a heat dissipation gap filler, and the first bus bar has an accommodating portion that accommodates at least a portion of the head of the bolt or at least a portion of the nut. Effect of the Invention

[0007] According to the electrical junction box of the present disclosure, the amount of heat dissipation gap filler used can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a mounting structure of an electric junction box according to an embodiment. [Diagram 2] FIG. 2 is a schematic exploded cross-sectional view of the electrical junction box according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described. The electrical connection box of the present disclosure comprises: [1] An electrical connection box comprising: a resin base member having a through hole penetrating downward; a first bus bar arranged above the base member at a position corresponding to the through hole; a second bus bar arranged above the first bus bar and stacked thereon; and bolts and nuts fastening the first bus bar to the second bus bar at a position corresponding to the through hole, the electrical connection box being arranged above a heat dissipation member, with an underside of the first bus bar exposed from the through hole being connected to the heat dissipation member via a heat dissipation gap filler, wherein the first bus bar has an accommodating portion that accommodates at least a portion of a head of the bolt or at least a portion of the nut.

[0010] According to this configuration, the first busbar has a housing portion that houses at least a part of the head of the bolt or at least a part of the nut, so that the head of the bolt or the nut can be prevented from protruding significantly from the lower surface of the first busbar. This makes it possible to reduce the gap between the lower surface of the first busbar and the heat dissipation member. This makes it possible to reduce the amount of heat dissipation gap filler used between the lower surface of the first busbar and the heat dissipation member.

[0011] [2] In the above item [1], the storage section may store at least a portion of the head. According to this configuration, the housing accommodates at least a part of the head, so that the underside of the head is the lowest surface. Therefore, the amount of heat dissipation gap filler used can be reduced compared to a configuration in which the housing accommodates at least a part of the nut. That is, in a configuration in which the housing accommodates at least a part of the nut, the shaft of the bolt may protrude further downward from the nut, but this can be avoided, so that the gap between the underside of the first bus bar and the heat dissipation member can be made smaller. Therefore, the amount of heat dissipation gap filler used that is interposed between the underside of the first bus bar and the heat dissipation member can be reduced.

[0012] [3] In the above [1] or [2], the accommodating portion may accommodate the entire head or the nut so that the underside of the head or the underside of the nut is flush with the underside of the first bus bar.

[0013] According to this configuration, the accommodating portion accommodates the entire head or nut so that the underside of the head or the underside of the nut is flush with the underside of the first bus bar, thereby reducing the amount of heat dissipation gap filler used compared to a configuration that accommodates only part of the head or part of the nut.

[0014] [4] In any one of the above [1] to [3], the accommodating portion may be configured to be in close contact with the head or the nut without any gaps. According to this configuration, the housing is configured to be in close contact with the head or the nut without any gaps, so the amount of heat dissipation gap filler used can be reduced compared to a configuration having a gap. That is, in a configuration in which the housing has a gap with the head or the nut, the heat dissipation gap filler gets into the gap, increasing the amount of heat dissipation gap filler used, but this can be avoided, so the amount of heat dissipation gap filler used can be reduced.

[0015] [5] In any one of the above [1] to [4], the first bus bar may be thicker than the second bus bar. According to this configuration, since the first busbar is thicker than the second busbar, it is easy to provide an accommodating portion for accommodating at least a part of the head of a bolt or at least a part of a nut. That is, for example, in a configuration in which the second busbar arranged above the first busbar is thicker than the first busbar, it is difficult to provide an accommodating portion in the thin first busbar. In contrast, since the first busbar is thicker than the second busbar, it is easy to provide an accommodating portion.

[0016] [Details of the embodiment of the present disclosure] Specific examples of the electrical connection box of the present disclosure will be described below with reference to the drawings. In each drawing, for convenience of explanation, some of the configuration may be exaggerated or simplified. In addition, the dimensional ratio of each part may differ in each drawing. In this specification, "parallel," "orthogonal," and "perfect circle" do not only mean strictly parallel, orthogonal, or perfect circle, but also include approximately parallel, orthogonal, or perfect circle within the range of the action and effect of this embodiment. Note that the present invention is not limited to these examples, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0017] (Configuration of electrical connection box 11) 1 and 2, the electrical junction box 11 includes a base member 12, a first bus bar 13, a second bus bar 14, bolts 15, and nuts 16. The electrical junction box 11 of this embodiment is mounted on a vehicle, for example, and is connected between an FC stack that generates electricity using hydrogen and an inverter connected to a motor, through which a large current flows. Note that the electrical junction box 11 can be disposed in any orientation relative to the vehicle, but the following description will use an upward Z1 and a downward Z2 in the figures.

[0018] (Configuration of base member 12) The base member 12 is made of resin. The base member 12 constitutes the bottom of the case of the electrical junction box 11. The electrical junction box 11 includes, for example, a lid (not shown) that constitutes the upper part of the case while being fixed to the base member 12. The base member 12 has a through hole 12a that penetrates downward Z2.

[0019] (Configuration of first bus bar 13 and second bus bar 14) The first bus bar 13 and the second bus bar 14 are made of a metal plate material. The first bus bar 13 is thicker than the second bus bar 14. Specifically, the first bus bar 13 in this embodiment is a thick copper bus bar that is thicker than the second bus bar 14. Note that in each drawing, the thicknesses of the first bus bar 13 and the second bus bar 14 are not accurately shown, but are shown diagrammatically. Furthermore, the electrical junction box 11 includes electric circuit components such as a choke coil and a capacitor (not shown) that are connected to the first bus bar 13 and the second bus bar 14.

[0020] 1, the first bus bar 13 is disposed above the base member 12 at a position corresponding to the through hole 12a. The first bus bar 13 has a first insertion hole 13a penetrating downward Z2 at a position facing the through hole 12a. The first bus bar 13 also has a housing portion 13c recessed upward Z1 from the lower surface 13b at a position corresponding to the first insertion hole 13a. The first insertion hole 13a is in communication with the housing portion 13c.

[0021] The second bus bar 14 is disposed above the first bus bar 13 in an overlapping position Z1. The second bus bar 14 has a second insertion hole 14a penetrating downward Z2 at a position opposite the first insertion hole 13a.

[0022] (Configuration of bolt 15 and nut 16) The bolt 15 has a head 15a and a shaft 15b. The head 15a extends from the end of the shaft 15b in a flange shape. The head 15a in this embodiment is formed in a circular shape and has a plurality of protrusions (not shown) in the circumferential direction that protrude radially outward. The shaft 15b has a male thread formed on its outer circumferential surface and can be screwed into a female thread formed on the inner circumferential surface of the nut 16.

[0023] Head 15a is accommodated in accommodation portion 13c of first bus bar 13. More specifically, bolt 15 has shaft portion 15b inserted into first insertion hole 13a from downward side Z2 toward upward side Z1 of first bus bar 13, and head 15a is accommodated in accommodation portion 13c. Accommodating portion 13c in this embodiment accommodates entire head 15a such that lower surface 15c of head 15a is flush with lower surface 13b of first bus bar 13.

[0024] The housing portion 13c is configured to closely contact the head portion 15a without any gaps. In this embodiment, the head portion 15a is press-fitted into the housing portion 13c. The housing portion 13c is configured to closely contact the head portion 15a having a protrusion (not shown) without any gaps, thereby preventing the bolt 15 from rotating.

[0025] 1, nut 16 is screwed from above Z1 onto shaft portion 15b inserted through first insertion hole 13a and second insertion hole 14a, so that bolt 15 and nut 16 fasten first bus bar 13 and second bus bar 14 together at positions corresponding to through holes 12a.

[0026] (Mounting structure of electrical connection box 11) As shown in FIG. 1, the electrical connection box 11 is disposed above Z1 the heat dissipation member 21, and the lower surface 13b of the first bus bar 13 exposed from the through hole 12a is connected to the heat dissipation member 21 via a heat dissipation gap filler 22.

[0027] The heat dissipation member 21 is made of a metal material such as aluminum that has high heat dissipation properties. The heat dissipation gap filler 22 is made of silicone grease or the like, has high thermal conductivity and insulation properties, and is pasty so as to be capable of filling gaps and uneven surfaces.

[0028] Heat dissipation gap filler 22 is interposed so as to be sandwiched between heat dissipation member 21 and lower surface 13b of first bus bar 13 and lower surface 15c of head portion 15a exposed from through hole 12a.

[0029] Next, the operation of the electrical junction box 11 configured as above will be described. Electrical junction box 11 generates heat due to a large current flowing through first bus bar 13 and second bus bar 14. This heat is transferred to heat dissipation member 21 via heat dissipation gap filler 22 interposed between lower surface 13b of first bus bar 13 and heat dissipation member 21, and is mainly dissipated from heat dissipation member 21. This prevents first bus bar 13 and second bus bar 14, and ultimately electrical junction box 11, from becoming too hot.

[0030] Next, the effects of the above embodiment will be described below. (1) First bus bar 13 has accommodation portion 13c that accommodates head 15a of bolt 15, and therefore head 15a can be prevented from protruding significantly from underside 13b of first bus bar 13. This makes it possible to reduce the distance between underside 13b of first bus bar 13 and heat dissipation member 21. This makes it possible to reduce the amount of heat dissipation gap filler 22 used between underside 13b of first bus bar 13 and heat dissipation member 21. In addition, because the distance from underside 13b of first bus bar 13 to heat dissipation member 21 is shortened, heat dissipation is also improved.

[0031] (2) Since the housing portion 13c houses the head portion 15a, the lower surface 15c of the head portion 15a becomes the lowermost surface. Therefore, for example, the amount of heat dissipation gap filler 22 used can be reduced compared to a configuration in which the housing portion 13c houses at least a part of the nut 16. That is, in a configuration in which the housing portion 13c houses at least a part of the nut 16, the shaft portion 15b of the bolt 15 may protrude further downward Z2 from the nut 16, but this can be avoided. Therefore, the gap between the lower surface 13b of the first bus bar 13 and the heat dissipation member 21 can be made smaller. Therefore, the amount of heat dissipation gap filler 22 used to be interposed between the lower surface 13b of the first bus bar 13 and the heat dissipation member 21 can be made smaller.

[0032] (3) Housing portion 13c houses all of head portion 15a such that lower surface 15c of head portion 15a is flush with lower surface 13b of first bus bar 13. Therefore, the amount of heat dissipation gap filler 22 used can be reduced compared to a configuration in which only a portion of head portion 15a is housed.

[0033] (4) Because the accommodation portion 13c is configured to be in close contact with the head portion 15a with no gap, it is possible to reduce the amount of heat dissipation gap filler 22 used, compared to a configuration having a gap. That is, in a configuration in which the accommodation portion 13c has a gap with the head portion 15a, the heat dissipation gap filler 22 gets into the gap, increasing the amount of heat dissipation gap filler 22 used, but because this can be avoided, the amount of heat dissipation gap filler 22 used can be reduced.

[0034] (5) Because the first bus bar 13 is thicker than the second bus bar 14, it is easy to provide the accommodating portion 13c that accommodates the head 15a of the bolt 15. That is, for example, in a configuration in which the second bus bar 14, which is arranged above the first bus bar 13 in the Z1 direction, is thicker than the first bus bar 13, it is difficult to provide the accommodating portion 13c in the thin first bus bar 13. In contrast, because the first bus bar 13 is thicker than the second bus bar 14, it is easy to provide the accommodating portion 13c.

[0035] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction. In the above embodiment, the accommodation portion 13c accommodates the head 15a of the bolt 15, but this is not limiting and the accommodation portion 13c may accommodate at least a part of the nut 16. Even in this case, compared to a configuration in which the entire nut 16 is disposed below the lower surface 13b of the first bus bar 13 at Z2, the nut 16 can be prevented from significantly protruding from the lower surface 13b of the first bus bar 13, and the amount of heat dissipation gap filler 22 used can be reduced.

[0036] Furthermore, when accommodating portion 13c is configured to accommodate nut 16, accommodating portion 13c may be configured to accommodate all of nut 16 such that the lower surface of nut 16 is flush with lower surface 13b of first bus bar 13. Furthermore, when accommodating portion 13c is configured to accommodate nut 16, accommodating portion 13c may be configured to be in close contact with nut 16 without any gaps.

[0037] In the above embodiment, the accommodating portion 13c accommodates the entire head 15a so that the lower surface 15c of the head 15a is flush with the lower surface 13b of the first busbar 13. However, this is not limited to this, and the accommodating portion 13c may be configured to accommodate, for example, only a portion of the head 15a.

[0038] In the above embodiment, the housing portion 13c is configured to be in close contact with the head portion 15a without any gap, but this is not limited thereto, and the housing portion 13c may be configured to have a gap between the head portion 15a and the housing portion 13c. In this case, the housing portion 13c is preferably configured to prevent the bolt 15 from rotating.

[0039] In the above embodiment, the first bus bar 13 is thicker than the second bus bar 14, but this is not limited to the above. The first bus bar 13 may be the same thickness as the second bus bar 14, or may be thinner than the second bus bar 14.

[0040] In the above embodiment, the head 15a of the bolt 15 is formed in a circular shape and has a plurality of protrusions (not shown) in the circumferential direction that protrude radially outward. However, this is not limited to this and the head 15a may be formed in, for example, a hexagon or a rectangle.

[0041] In the above embodiment, the electrical connection box 11 is, for example, mounted on a vehicle and connected between an FC stack that generates electricity using hydrogen and an inverter that is connected to a motor, but is not limited to this and may be connected to other electrical equipment. [Explanation of symbols]

[0042] 11 Electrical junction box 12 Base material 12a Through hole 13 No. 1 bus bar 13a First insertion hole 13b Bottom side 13c Storage section 14 Second bus bar 14a Second insertion hole 15 Volts 15a head 15b Shaft 15c Bottom side 16 Nut 21 Heat dissipation material 22 Heat dissipation gap filler Z1 upper Z2 downward

Claims

1. A resin base member having a through hole extending downward; a first bus bar disposed above the base member at a position corresponding to the through hole; a second bus bar disposed above the first bus bar; a bolt and a nut for fastening the first bus bar and the second bus bar together at a position corresponding to the through hole; an electrical connection box disposed above a heat dissipation member, and a lower surface of the first bus bar exposed from the through hole is connected to the heat dissipation member via a heat dissipation gap filler, The first bus bar has an accommodating portion that accommodates at least a part of a head of the bolt or at least a part of the nut. Electrical junction box.

2. The storage portion stores at least a portion of the head.

2. The electrical junction box according to claim 1.

3. the accommodating portion accommodates the entire head or the entire nut such that a lower surface of the head or a lower surface of the nut is flush with a lower surface of the first bus bar.

2. The electrical junction box according to claim 1.

4. The housing portion is configured to be in close contact with the head or the nut without any gap.

2. The electrical junction box according to claim 1.

5. The first bus bar is thicker than the second bus bar.

2. The electrical junction box according to claim 1.

Images