Bus bar coupling structure and bus bar

Abstract

To prevent or suppress, in a bus bar coupling structure having a bus bar coupled to an electric member via a screw coupling structure, looseness of the screw coupling structure that occurs when in use.SOLUTION: In a bus bar coupling structure, a bus bar has a plate-like bonding region. The bus bar is coupled via a screw coupling structure in such a condition that the bonding region is bonded to an attachment surface of an electric member to be coupled. A first thermosetting type film is inserted between the bonding region and the attachment surface. Preferably, the first thermosetting type film has conductivity and is preliminarily adhered to the bonding region. Preferably, a second thermosetting type film is inserted between a head portion of a fastening member and the bonding region. Preferably, the second thermosetting type film has conductivity and is preliminarily adhered to the bonding region.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a busbar connection structure in which a busbar is connected to an electrical member, and to a busbar connected to an electrical member. [Background technology]

[0002] 2. Description of the Related Art Bus bars that electrically connect first and second electrical components, such as storage batteries, are widely used in various fields.

[0003] It is desirable for the bus bar to have as low an electrical resistance as possible between the first and second electrical members, and in order to achieve this, it is necessary to stabilize the joints between the bus bar and the first and second members.

[0004] Typically, the busbars are connected to corresponding electrical components via a screw connection mechanism (see Patent Documents 1 and 2).

[0005] In a configuration in which the bus bar is connected to the electrical component via the screw connection mechanism, if the bus bar is used in an environment where it is subject to vibration and / or impact, such as when used as a component for electrically connecting storage cells in an in-vehicle battery, the screw connection mechanism may loosen, and the stability of the connection between the bus bar and the electrical component may be compromised. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-062045 A [Patent Document 2] JP 2017-033694 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the conventional technology, and has a first object to provide a busbar connection structure in which a busbar is connected to an electrical component via a screw connection mechanism, which can effectively prevent or reduce loosening of the screw connection mechanism during use. A second object of the present invention is to provide a busbar that is connected to an electrical component via a screw connecting mechanism, and that can effectively prevent or reduce loosening of the screw connecting mechanism during use. [Means for solving the problem]

[0008] In order to achieve the first object, a first aspect of the present invention provides a busbar connection structure in which a conductive busbar is electrically and mechanically connected to an electrical component, the busbar having a flat joint area, the joint area being joined to a mounting surface of the electrical component and connected to the electrical component via a screw connection mechanism, and a first thermosetting film being interposed between the joint area and the mounting surface.

[0009] In a first form in which the electrical component is configured such that the mounting surface acts as an electrical connection portion, the screw connection mechanism includes a fastening member having a shaft portion with a thread formed on its outer peripheral surface to act as a screw portion and a head provided on one end side of the shaft portion, and a screw hole provided on the mounting surface so that the shaft portion can be screwed in. The joining area has an engagement portion consisting of an opening or slit through which the shaft portion is inserted but not the head portion, and the first thermosetting film is conductive and configured to allow the shaft portion to be inserted.

[0010] In the first embodiment, a second thermosetting film is preferably interposed between the head and the joint region. The second thermosetting film is configured so that the shaft portion can be inserted therethrough. Preferably, the second thermosetting film is adhered to the bonding area.

[0011] In a second form in which the electrical component has a main body having the mounting surface and a rod-shaped electrode terminal extending outward from the mounting surface and acting as an electrical connection portion, the screw connection mechanism has a screw portion formed on the outer peripheral surface of the electrode terminal and a nut portion screwed into the screw portion. The joining region is provided with an engagement portion through which the electrode terminal is inserted but through which the nut portion is not inserted.

[0012] In the second embodiment, a conductive second thermosetting film is preferably interposed between the nut portion and the joint region, and the second thermosetting film is configured so that the electrode terminal can be inserted therethrough.

[0013] Preferably, the second thermosetting film is adhered to the bonding area.

[0014] In various configurations of the first aspect, the first thermosetting film is preferably adhered to the bonding area.

[0015] In order to achieve the first object, a second aspect of the present invention provides a busbar connection structure in which a conductive busbar is electrically and mechanically connected to an electric component, the busbar having a flat joint region, and being connected to the electric component via a screw connection mechanism with the joint region joined to a mounting surface of the electric component, the screw connection mechanism having a fastening member having a shank portion on which a thread is formed and a head provided on one end side of the shank portion, and a screw hole provided on the mounting surface so that the shank portion can be screwed into, the joint region is provided with an engagement portion through which the shank portion is inserted but not the head portion, and a thermosetting film is interposed between the head portion and the joint region, and the thermosetting film is configured to allow the shank portion to be inserted.

[0016] In the second embodiment, the thermosetting film is preferably adhered to the bonding area.

[0017] In addition, in order to achieve the second object, a third aspect of the present invention provides a conductive busbar that is electrically and mechanically connected to an electric component via a screw connecting mechanism, the busbar having a flat joint region that is joined to a mounting surface of the electric component in a connected state with the electric component, an engagement portion formed in the joint region so that a screw portion that is part of the screw connecting mechanism can be inserted therethrough, and a first thermosetting film adhered to the surface of the joint region facing the mounting surface.

[0018] Preferably, the first thermosetting film is electrically conductive.

[0019] Preferably, the busbar according to the third aspect of the present invention has a second thermosetting film adhered to the surface of the bonding region opposite to the opposing surface. Effect of the Invention

[0020] According to the bus bar connection structure of the present invention, it is possible to effectively prevent or reduce loosening of the screw connection mechanism that connects the bus bar to the electrical component due to vibration, impact, and the like during use. Furthermore, the bus bar according to the present invention can effectively prevent or reduce loosening of the screw connection mechanism that connects the bus bar to an electrical component due to vibration, impact, and the like during use. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a front view of a busbar assembly to which a busbar connection structure according to a first embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a plan view of the bus bar assembly shown in FIG. [Diagram 3] FIG. 3 is a perspective view of the bus bar assembly shown in FIGS. [Figure 4] FIG. 4 is an exploded perspective view of the bus bar assembly shown in FIGS. [Diagram 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] 6(a) to 6(f) are explanatory diagrams of one example of the bus bar connection structure according to the first embodiment. [Figure 7] FIG. 7 is a graph showing the results of a test performed on the above-described embodiment regarding the return torque required to release the fastening member. [Figure 8] FIG. 8 is a graph showing the results of a verification carried out on a comparative example regarding the return torque required to release the fastening member. [Figure 9] FIG. 9 is an exploded perspective view of a busbar assembly to which a busbar connection structure according to the second embodiment of the present invention is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] First embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a bus bar connection structure according to the present invention will be described with reference to the accompanying drawings. 1 to 4 respectively show a front view, a plan view, a perspective view, and an exploded perspective view of a busbar assembly 1 to which a busbar connection structure according to the present embodiment is applied. FIG. 5 shows a partial cross-sectional view of the busbar assembly 1 taken along line VV in FIG.

[0023] The bus bar connection structure electrically and mechanically connects the conductive bus bars 10 to corresponding electrical components.

[0024] The busbar assembly 1 to which the busbar connection structure of this embodiment is applied includes a busbar 10, and a first electrical member 50(1) and a second electrical member 50(2) such as a storage battery that are electrically connected by the busbar 10, as shown in Figures 1 to 4.

[0025] The first and second electrical members 50(1), 50(2) have substantially the same configuration. Therefore, the components of the first and second electrical members 50(1) and 50(2) are denoted by the same reference numerals, and a description of the second electrical member 50(2) will be omitted as appropriate.

[0026] As shown in FIG. 4 and other figures, the first electrical member 50 ( 1 ) has a body 60 having a mounting surface 62 . In this embodiment, the first electrical member 50 ( 1 ) is configured so that the mounting surface 62 also functions as an electrical connection portion that is electrically connected to the bus bar 10 .

[0027] As shown in Figures 1 to 5, the busbar 10 has a flat joint region 12, and is connected to the first electrical member 50(1) via a screw connection mechanism with the joint region 12 joined to the mounting surface 62. The bus bar 10 is made of a conductive metal such as Cu.

[0028] In this embodiment, the screw connection mechanism has a screw hole 65 provided in the mounting surface 62 and a fastening member 70 having a shaft portion 72 with a threaded portion that is screwed into the screw hole 65.

[0029] The fastening member 70 has, in addition to the shaft portion 72 , a head portion 75 whose diameter is enlarged from the shaft portion 72 . In this embodiment, the fastening member 70 has, integrally therewith, a flange portion 77 between the head portion 75 and the shaft portion 72, the flange portion 77 having a larger diameter than the head portion 75.

[0030] The bus bar 10 has, in its joint region 12, an engagement portion 15 through which the shaft portion 72 is inserted but the head portion 75 is not inserted.

[0031] As shown in Figs. 4 and 5, in this embodiment, the joining region 12 is provided with an opening that functions as the engagement portion 15, but it is also possible to provide a slit instead of the opening.

[0032] The bus bar connection structure further includes a first thermosetting film 20 interposed between the joining area 12 and the mounting surface 62 .

[0033] As shown in Figures 4 and 5, in this embodiment, the first thermosetting film 20 is provided with a first film side engagement portion 22 through which the shaft portion 72 is inserted but the head portion 75 is not inserted.

[0034] In this embodiment, the first film side engagement portion 22 is formed by an opening, but instead, it may be formed by a slit.

[0035] The first thermosetting film 20 interposed between the joining region 12 of the busbar 10 and the mounting surface 62 of the first electrical member 50(1) hardens due to heat generated by the busbar 10 and the first electrical member 50(1) when the busbar 10 is placed in a usable state (i.e., when current flows between the first electrical member 50(1) and the busbar 10), and firmly bonds the fastening member 70.

[0036] Therefore, even when the bus bar 10 is used in an in-vehicle battery or other conditions in which it is subjected to vibrations and shocks, loosening of the screw connection mechanism can be effectively prevented or reduced.

[0037] The first thermosetting film 20 can be made of various materials having thermosetting properties, but in this embodiment, it is made of a material having electrical conductivity. According to this configuration, the area of ​​the conductive path between the mounting surface 62, which also functions as an electrical connection portion, and the joining region 12 of the bus bar 10 can be effectively secured, and an increase in electrical resistance between the first electrical member 50(1) and the bus bar 10 can be effectively prevented or reduced.

[0038] Preferably, the first thermosetting film 20 is pre-adhered to the joining area 12 of the busbar 10 prior to coupling the busbar 10 to a corresponding electrical component (e.g., the first electrical component 50(1)) by the screw coupling mechanism.

[0039] According to this configuration, the efficiency of the connection work of the bus bar 10 to the first electrical component 50(1) can be improved when the first thermosetting film 20 is interposed between the mounting surface 62 and the joining area 12.

[0040] As shown in Figures 4 and 5, the busbar connection structure further includes a second thermosetting film 30 interposed between a head 75 (the flange portion 77 in this embodiment) of the fastening member 70 and the joining region 12 of the busbar 10.

[0041] The second thermosetting film 30 is provided with a second film side engagement portion 32 through which the shaft portion 72 is inserted but through which the head portion 75 is not inserted.

[0042] The second film side engagement portion 32 is formed by an opening, but instead of this, it may be formed by a slit.

[0043] By providing the second thermosetting film 30, the adhesion of the fastening member 70 can be further improved by the hardening action of the second thermosetting film 30 due to heat generated by the bus bar 10 and the fastening member 70 in response to the passage of current.

[0044] The second thermosetting film 30 can be made of various materials having thermosetting properties, but in this embodiment, it is made of a material having electrical conductivity. According to this configuration, an electrical path between the first electrical member 50(1) and the bus bar 10 via the fastening member 70 can be effectively secured.

[0045] Preferably, the second thermosetting film 30 is pre-adhered to the joining area 12 of the busbar 10 prior to coupling the busbar 10 to a corresponding electrical component (e.g., the first electrical component 50(1)) by the screw coupling mechanism.

[0046] According to this configuration, the efficiency of the connection work of the bus bar 10 to the first electrical component 50(1) can be improved with the second thermosetting film 30 interposed between the head 75 and the joining area 12.

[0047] Here, the results of verification performed on one example of the bus bar connection structure according to the present embodiment will be described. FIG. 6 shows an explanatory diagram of the bus bar connection structure according to the embodiment.

[0048] As shown in FIG. 6(a), the bus bar 10 is made of copper and has a length of 40 mm, a width of 20 mm and a thickness of 3.5 mm, and has an engagement portion (opening) 15 having a diameter of 8 mm in a joining region 12 on one end side.

[0049] As shown in FIG. 6(b), first and second thermosetting films 20, 30 are temporarily attached to one and the other sides of the joining region 12 of the bus bar 10 in the plate thickness direction.

[0050] In this embodiment, the first and second thermosetting films 20, 30 were made of thermosetting conductive adhesive sheets (urethane resin base). Specifically, in this embodiment, the first and second thermosetting films 20, 30 have a thickness of 60 μm, and the lengths of the first side along the longitudinal direction of the busbar and the second side along the width direction are 20 mm and 20 mm, respectively. In addition, reference numerals 27 and 37 in FIG. 6(b) denote separators.

[0051] In this embodiment, the thermosetting conductive adhesive sheet (urethane resin base) used as the first and second thermosetting films 20, 30 has separators 27, 37 on both sides, and Figure 6 (b) shows a state in which the separator on one side in the thickness direction has been removed and the thermosetting conductive adhesive sheet (urethane resin base) is temporarily attached to the bonding area 12 of the bus bar 10.

[0052] The first and second thermosetting films 20 and 30 were formed with openings having a diameter of 8 mm to act as the first and second film side engagement recesses 22 and 32, respectively.

[0053] The bonding area 12 of the bus bar 10 to which the first and second thermosetting films 20, 30 were temporarily attached was heated to 170°C for 3 minutes using a hot plate (not shown) while applying a narrow pressure (weight of 2.5 kg), thereby bonding the first and second thermosetting films 20, 30 to the bonding area of ​​the bus bar (Figure 6(c)).

[0054] The bus bar 10 (FIG. 6(d)) from which the remaining separators 27, 37 of the first and second thermosetting films 20, 30 have been removed is fastened to the mounting surface 57 of the attachment member 55 by the fastening member 70 (FIG. 6(e)).

[0055] In this embodiment, an M6 flange bolt was used as the fastening member 70. Further, the mounting surface 57 is formed with a screw hole 58 into which an M6 bolt is screwed.

[0056] The fastening members 70 (M6 flanged bolts) were screwed into the screw holes 58 with a torque of 1 N·m using a digital torque wrench, thereby fastening the bus bars 10 to the mounting members 55.

[0057] The assembly 1' in which the bus bar 10 was fastened to the mounting member 55 was heated in a high-temperature furnace (160°C) for one hour to harden the first and second thermosetting films 20, 30 (Fig. 6(f)).

[0058] Ten assemblies 1' according to the embodiment formed in this manner were prepared, and the return torque required to release the fastening member 70 (the M6 ​​flanged bolt) was measured for each of the ten assemblies 1' according to the embodiment using a digital torque wrench. The results are shown in Figure 7.

[0059] As a comparative example, an assembly (not shown) in which a bus bar not having the first and second thermosetting films 20, 30 was fastened to the mounting member 55 was prepared. The tightening torque in the comparative example was the same as that in the example.

[0060] Ten assemblies according to the comparative example formed in this manner were prepared, and the return torque required to release the fastening members (M6 flanged bolts) of the ten assemblies according to the comparative example was measured using a digital torque wrench. The results are shown in Figure 8.

[0061] As is clear from FIGS. 7 and 8, the return torque in the assembly 1' according to the embodiment was greater than the return torque in the assembly according to the comparative example.

[0062] This means that the fastening members 70 in the assembly 1' according to the embodiment are more firmly fixed than in the assembly according to the comparative example.

[0063] Embodiment 2 Hereinafter, a bus bar connection structure according to another embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 9 shows an exploded perspective view of a busbar assembly 2 to which the busbar connection structure according to this embodiment is applied. In the figure, the same members as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted as appropriate.

[0064] Compared to the busbar assembly 1, the busbar assembly 2 has first and second electrical members 80(1), 80(2) instead of the first and second electrical members 50(1), 50(2).

[0065] In detail, the busbar assembly 2 includes the busbar 10, the first and second thermosetting films 20, 30 adhered to the joint region 12 of the busbar 10, and the first and second electrical components 80(1), 80(2) such as storage batteries electrically connected by the busbar 10.

[0066] The first and second electrical members 80(1), 80(2) have substantially the same configuration. Therefore, the components of the first and second electrical members 80(1) and 80(2) are denoted by the same reference numerals, and the description of the second electrical member 80(2) will be omitted as appropriate.

[0067] As shown in FIG. 9, the first electrical member 80(1) has a main body portion 90 having the mounting surface 62, and a rod-shaped electrode terminal 95 extending outward from the mounting surface 62 and acting as an electrical connection portion.

[0068] The electrode terminal 95 has a threaded portion on its outer circumferential surface, and forms a part of a screw coupling mechanism that fastens the bus bar 10 to the first electrical member 80(1).

[0069] That is, in the busbar connection structure according to the present embodiment, the screw connection mechanism has a threaded portion formed on the outer peripheral surface of the electrode terminal 95 and a nut portion 100 that is screwed into the threaded portion.

[0070] In this embodiment, the nut portion 100 has a nut head portion 105 and a flange portion 107 that is enlarged in diameter from the nut head portion 105 .

[0071] The first thermosetting film 20 interposed between the mounting surface 62 and the joining region 12 of the bus bar 10 may be either insulating or conductive, but is preferably conductive.

[0072] In this embodiment, the second thermosetting film 30 is interposed between the nut portion 100 and the joining region 12 . The second thermosetting film 30 may also be either insulating or conductive, but is preferably conductive.

[0073] As in the first embodiment, the first and second thermosetting films 20, 30 are preferably pre-adhered to the bonding area 12 of the busbar . [Explanation of symbols]

[0074] 10 Busbar 12 Joint area 15. Entry 20 First thermosetting film 30 Second thermosetting film 50(1), 80(1) First Electrical Component 50(2), 80(2) Second electrical component 60, 90 Main body 62 Mounting surface 65 screw hole 70 Fastening members 72 Shaft 75 Head 95 Electrode terminal 100 Nut

Claims

1. A bus bar connection structure in which a conductive bus bar is electrically and mechanically connected to an electric member, the bus bar has a flat joint region, and is connected to the electrical component via a screw connection mechanism in a state where the joint region is joined to a mounting surface of the electrical component; A bus bar connection structure, comprising: a first thermosetting film interposed between the joint area and the mounting surface.

2. The electrical member is configured such that the mounting surface serves as an electrical connection; The screw connection mechanism includes a fastening member having a shaft portion having a thread formed on an outer peripheral surface thereof so as to function as a screw portion, and a head portion provided on one end side of the shaft portion, and a screw hole provided on the mounting surface into which the shaft portion is screwed, The joining region is provided with an engagement portion through which the shaft portion is inserted and through which the head portion is not inserted, 2. The bus bar connection structure according to claim 1, wherein the first thermosetting film is conductive and configured so that the shaft portion can be inserted therethrough.

3. A second thermosetting film is interposed between the head and the bonding area, The bus bar connection structure according to claim 2 , wherein the second thermosetting film is configured so that the shaft portion can be inserted therethrough.

4. The bus bar connection structure according to claim 3 , wherein the second thermosetting film is adhered to the joining area.

5. the electrical member has a body portion having the mounting surface, and a rod-shaped electrode terminal extending outward from the mounting surface and acting as an electrical connection portion; the screw coupling mechanism includes a threaded portion formed on an outer circumferential surface of the electrode terminal and a nut portion screwed into the threaded portion, 2. The bus bar connection structure according to claim 1, wherein the joint region is provided with an engagement portion through which the electrode terminal is inserted and through which the nut portion is not inserted.

6. A conductive second thermosetting film is interposed between the nut portion and the joining region, The bus bar connection structure according to claim 5 , wherein the second thermosetting film is configured so that the electrode terminal can be inserted therethrough.

7. The bus bar connection structure according to claim 6 , wherein the second thermosetting film is adhered to the joining area.

8. 8. The bus bar connection structure according to claim 1, wherein the first thermosetting film is adhered to the joining area.

9. A bus bar connection structure in which a conductive bus bar is electrically and mechanically connected to an electric member, the bus bar has a flat joint region, and is connected to the electrical component via a screw connection mechanism in a state where the joint region is joined to a mounting surface of the electrical component; the screw connection mechanism includes a fastening member having a shaft portion on which a screw is formed and a head portion provided on one end side of the shaft portion, and a screw hole provided on the mounting surface so that the shaft portion can be screwed into the screw hole; The joining region is provided with an engagement portion through which the shaft portion is inserted and through which the head portion is not inserted, A thermosetting film is interposed between the head and the bonding area, The thermosetting film is configured so that the shaft portion can be inserted therethrough.

10. The bus bar connection structure according to claim 9 , wherein the thermosetting film is adhered to the joining area.

11. A conductive bus bar electrically and mechanically coupled to an electrical component via a screw coupling mechanism, a flat joint region that is joined to a mounting surface of the electrical component when connected to the electrical component, an engagement portion formed in the joint region so that a screw portion that is part of the screw connection mechanism can be inserted therethrough, and a first thermosetting film adhered to a surface of the joint region that faces the mounting surface.

12. The bus bar according to claim 11 , wherein the first thermosetting film is electrically conductive.

13. 13. The bus bar according to claim 11, further comprising a second thermosetting film adhered to a surface of the bonding region opposite the facing surface.

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