Busbar fastening structure

Abstract

This invention provides a busbar fastening structure that can achieve stable electrical contact reliability regardless of the material combination of the busbars. [Solution] The system comprises a first busbar 10 and a second busbar 20 fastened together by bolts 30 and nuts 40, a plurality of first protrusions 17 formed on the joint surface 13 of the first busbar 10 in an area corresponding to at least the seating surface 31 of the bolt 30 around the first bolt through hole 11, and a plurality of second protrusions 27 formed on the joint surface 23 of the second busbar 20 in an area corresponding to at least the seating surface 41 of the nut 40 around the second bolt through hole 21. When the first busbar 10 and the second busbar 20 are fastened together, the plurality of first protrusions 17 and the plurality of second protrusions 27 intersect with each other.

Description

Technical Field

[0001] The present invention relates to a fastening structure for a bus bar.

Background Art

[0002] Conventionally, in various electrical connection parts, a fastening structure for a bus bar that is fastened and fixed to a fastened member (such as a bus bar) by a bolt fastening mechanism has been used (see, for example, Patent Documents 1 to 3).

[0003] By the way, in bolt fastening connection using a bus bar made of aluminum or an aluminum alloy, in order to ensure connection reliability, it is necessary to break the hard and thick oxide film (insulator) formed on the aluminum surface by bolt fastening and make a metal connection (adhesion) with the fastened member.

[0004] For example, in the connection structure disclosed in Patent Document 1, uneven portions are formed around a through hole on a contact surface of a terminal made of aluminum or an aluminum alloy with an attachment target (fastened member). And by stipulating that the contact area ratio in the bolt fastening state is 0.8 or less, an increase in the contact resistance over time at the interface between the terminal and the attachment target is suppressed.

[0005] Also, by making the Vickers hardness of the terminal 160 HV or less, when connecting the terminal and the attachment target, the convex portions of the uneven portions of the terminal are likely to be appropriately crushed, and the oxide film near the convex portions of the uneven portions is likely to be broken, so that conduction between the terminal and the attachment target is easily ensured.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0007] However, the connection structure described in Patent Document 1 is an invention specifically focused on securing a new surface by destroying the oxide film on the terminal side, which is made of aluminum or an aluminum alloy, which has low hardness. Therefore, in order to obtain a good electrical connection, it is also necessary to secure a new surface by destroying the oxide film on the mounting target side. That is, if the material of the mounting target side has an oxide film and is a hard metal material (copper or copper alloy), or if it is an aluminum material of the same type as the terminal and has a hard and thick oxide film, it may be difficult to destroy the oxide film on the mounting target side, and electrical contact reliability may not be obtained.

[0008] The present invention has been made in view of the above circumstances, and its objective is to provide a busbar fastening structure that can obtain stable electrical contact reliability regardless of the material combination of the busbars. [Means for solving the problem]

[0009] The above objective according to the present invention is achieved by the following configuration.

[0010] A first busbar and a second busbar are fastened and secured by bolts and nuts, A plurality of first protrusions are formed on the joint surface of the first busbar in an area corresponding to at least the seating surface of the bolt in the periphery of the first bolt through hole, The second busbar has a plurality of second protrusions formed on its joint surface in an area corresponding to at least the seating surface of the nut in the periphery of the second bolt through hole, In a state in which the first busbar and the second busbar are fastened and fixed together, the plurality of first protrusions and the plurality of second protrusions intersect each other. Busbar fastening structure. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a busbar fastening structure that can obtain stable electrical contact reliability regardless of the material combination of the busbars.

[0012] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by referring to the attached drawings and reading through the embodiments for carrying out the invention described below (hereinafter referred to as "embodiments"). [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic exploded perspective view illustrating the fastening structure of a busbar according to one embodiment of the present invention. [Figure 2] Figure 2(a) is an enlarged view of the main part of the first busbar shown in Figure 1, viewed from the joint side, and Figures 2(b) and (c) are the views of the section IIb-IIb and IIc-IIc in Figure 2(a), respectively. [Figure 3] Figure 3(a) is an enlarged view of the main part of the second busbar shown in Figure 1, viewed from the joint side, and Figures 3(b) and (c) are the views taken along the IIIb-IIIb and IIIc-IIIc sections in Figure 3(a), respectively. [Figure 4] Figure 4(a) is a longitudinal section view of the main part showing the fastening structure of a busbar fastened at the axial center, and Figure 4(b) is a view of the section IV-IV in Figure 4(a). [Figure 5] Figure 5(a) is a longitudinal cross-sectional view of the main part showing the fastening structure of a busbar with an offset axis, and Figure 5(b) is a view of the VV section in Figure 5(a). [Figure 6] Figure 6 is a schematic exploded perspective view illustrating a modified busbar fastening structure according to this embodiment. [Figure 7] Figure 7 is an enlarged view of the main parts of the first busbar and the second busbar, respectively, as seen from the joint surface side, according to another modified example of this embodiment. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

[0015] (Embodiment) FIG. 1 is a schematic exploded perspective view for explaining a fastening structure of a bus bar according to an embodiment of the present invention. (a) of FIG. 2 is an enlarged view of a main part seen from the joining surface 13 side of the first bus bar 10 shown in FIG. 1, and (b) and (c) of FIG. 2 are cross-sectional views taken along the arrow IIb-IIb and cross-sectional views taken along the arrow IIc-IIc in (a) of FIG. 2. (a) of FIG. 3 is an enlarged view of a main part seen from the joining surface 23 side of the second bus bar 20 shown in FIG. 1, and (b) and (c) of FIG. 3 are cross-sectional views taken along the arrow IIIb-IIIb and cross-sectional views taken along the arrow IIIc-IIIc in (a) of FIG. 3.

[0016] As shown in FIG. 1, in the fastening structure of the bus bar according to the present embodiment, the first bus bar 10 and the second bus bar 20 each having a flat band-like cross-sectional shape are fastened and fixed by bolts 30 and nuts 40.

[0017] These first bus bar 10 and second bus bar 20 are formed by pressing a metal plate made of a conductive metal into a predetermined shape, and have a substantially rectangular shape as a whole.

[0018] And, for example, it can be used in various electrical connection parts by being routed in the accommodating part of a housing integrally formed of an insulating resin to form a circuit body, or by providing an insulating coating on the outer peripheral surface except for the end part to form a wiring material.

[0019] The base materials of the first bus bar 10 and the second bus bar 20 according to the present embodiment may be made of any metal having conductivity, and examples thereof include copper, copper alloy, aluminum, or aluminum alloy. Further, whether the base materials of the first bus bar 10 and the second bus bar 20 are of the same kind or different kinds is not limited.

[0020] The surface treatment of the first busbar 10 and the second busbar 20 is, for example, silver, tin, nickel, or alloys thereof, and may include nickel-nickel alloy plating or copper plating as an undercoat. The surface treatment is even better if it is silver or tin.

[0021] Furthermore, if the material of the first busbar 10 and the second busbar 20 is aluminum or an aluminum alloy, plating is applied after zincate treatment or double zincate treatment.

[0022] Surface treatment of the first busbar 10 and the second busbar 20 is not required.

[0023] As shown in Figures 1 and 2, a first bolt through-hole 11 is formed at the end of the first busbar 10 in this embodiment, through which a bolt 30 passes. The first bolt through-hole 11 is formed in a substantially circular shape by punching out the first busbar 10 in the thickness direction.

[0024] Furthermore, on the joint surface 13 of the first busbar 10 (the surface that overlaps with and contacts the second busbar 20 when bolted), multiple (eight in this embodiment) first protrusions 17 are formed in an area of ​​at least 60 cm corresponding to the seating surface 31 of the bolt 30 in the periphery of the first bolt through hole 11.

[0025] Here, the "range 60 corresponding to the seating surface 31 of the bolt 30" refers to the range having an outer diameter dimension obtained by adding the axial misalignment width of the first bolt through hole 11 ("gap between the inner diameter of the first bolt through hole 11 and the outer diameter of the bolt shaft portion 32" × 2) to the outer diameter of the seating surface 31 of the bolt 30.

[0026] Furthermore, as shown in Figure 2, the multiple first protrusions 17 are formed parallel to each other and at equal intervals with respect to the longitudinal direction (left-right direction in Figure 2) of the first busbar 10. These multiple first protrusions 17 are composed of multiple (9 in this embodiment) grooves 15 recessed in the joint surface 13 of the first busbar 10.

[0027] These multiple grooves 15 can be formed, for example, during press working in the forming process of the first busbar 10 (such as providing the first bolt through-holes 11). The grooves 15 have a rectangular cross-sectional shape, and their depth is at least deeper than the surface roughness and rolling marks of the joint surface 13. Thus, the first protrusion 17, which is composed of multiple grooves 15, has a rectangular cross-sectional shape.

[0028] As shown in Figures 1 and 3, a second bolt through-hole 21 is formed at the end of the second busbar 20 in this embodiment, through which a bolt 30 passes. The second bolt through-hole 21 is formed in a substantially circular shape by punching out the second busbar 20 in the thickness direction.

[0029] Furthermore, on the joint surface 23 of the second busbar 20 (the surface that overlaps with and contacts the first busbar 10 when bolted), a plurality of second protrusions 27 (10 in this embodiment) are formed in an area of ​​at least 60 corresponding to the seating surface 41 of the nut 40 in the periphery of the second bolt through hole 21.

[0030] Here, the "range 60 corresponding to the seating surface 41 of the nut 40" refers to the range having an outer diameter dimension obtained by adding the axial misalignment width of the second bolt through hole 21 ("gap between the inner diameter of the second bolt through hole 21 and the outer diameter of the bolt shaft portion 32" × 2) to the outer diameter of the seating surface 41 of the nut 40.

[0031] Furthermore, as shown in Figure 3, the multiple second protrusions 27 are formed parallel to the short direction (up and down in Figure 3) of the second busbar 20 and are spaced equally apart from each other. These multiple second protrusions 27 are composed of multiple (11 in this embodiment) grooves 25 recessed in the joint surface 23 of the second busbar 20.

[0032] These multiple grooves 25 can be formed, for example, during press working in the forming process of the second busbar 20 (such as providing the second bolt through-holes 21). The grooves 25 have a rectangular cross-sectional shape, and their depth is at least deeper than the surface roughness and rolling marks of the joint surface 23. Thus, the second protrusion 27, which is composed of multiple grooves 25, has a rectangular cross-sectional shape.

[0033] Next, the operation of the busbar fastening structure according to this embodiment, in which the first busbar 10 and the second busbar 20 are fastened and fixed together by bolts 30 and nuts 40, will be explained.

[0034] Figure 4(a) is a longitudinal section view of the main part showing the fastening structure of a busbar fastened at the axial center, and Figure 4(b) is a view of the section IV-IV in Figure 4(a). Figure 5(a) is a longitudinal section view of the main part showing the fastening structure of a busbar with an offset axial center, and Figure 5(b) is a view of the section VV in Figure 5(a).

[0035] First, the first busbar 10 and the second busbar 20 are arranged so that the joint surface 13, which has a plurality of first protrusions 17 formed thereon, and the joint surface 23, which has a plurality of second protrusions 27 formed thereon, are in contact with each other.

[0036] In this case, the first protrusion 17 and the second protrusion 27, which are in opposite directions (orthogonal directions), come into contact around the first bolt through hole 11 and the second bolt through hole 21, as shown in Figure 4(a). The contact points of the first protrusion 17 and the second protrusion 27 form the intersection points 50 of multiple squares aligned vertically and horizontally, as shown by dashed lines (double-dotted lines) in Figure 4(b).

[0037] Furthermore, in order for the joint surface 13 of the first busbar 10 and the joint surface 23 of the second busbar 20 to make stable contact, it is preferable that there be at least three intersection points 50 between the first protrusion 17 and the second protrusion 27.

[0038] Here, taking into account the misalignment (axis center misalignment) of the first busbar 10 and the second busbar 20, the range in which the multiple first protrusions 17 and second protrusions 27 are formed is set to be at least 60, which corresponds to the seating surface 31 of the bolt 30 (i.e., the seating surface 41 of the nut 40).

[0039] Therefore, as shown in Figure 5, even if there is a misalignment in the set position of the first busbar 10 and the second busbar 20, the number of intersection points 50 where the first protrusion 17 and the second protrusion 27 meet directly below the seating surface 31 of the bolt 30 and the seating surface 41 of the nut 40 does not change significantly (contact area).

[0040] Then, as the bolt 30 inserted through the first bolt through hole 11 and the second bolt through hole 21 is fastened with the nut 40 screwed onto the bolt 30, stress is transmitted to the contact surface of the intersection portion 50 at the joint surface 13 and the joint surface 23 via the seating surface 31 of the bolt 30 and the seating surface 41 of the nut 40.

[0041] Since the contact area between the joint surface 13 and the joint surface 23 that come into contact at multiple intersection points 50 is reduced compared to the contact area between conventional flat joint surfaces, the surface pressure acting on the contact interface is improved even when the same tightening torque as in the conventional method is applied.

[0042] Furthermore, as stress is transmitted to the contact surface of the aforementioned intersection portion 50, the first busbar 10 and the second busbar 20 are extended in the circumferential direction of the bolt 30, and parts of the plastically deformed first protrusion 17 and second protrusion 27 enter into the multiple grooves 15 and 25 at the contact interface.

[0043] Then, through the process in which parts of the plastically deformed first protrusion 17 and second protrusion 27 enter the multiple grooves 15 and 25, the oxide film (insulator) on the joint surface 13 of the first busbar 10 and the joint surface 23 of the second busbar 20 is destroyed, and the metals are joined (adhered) to each other.

[0044] According to the busbar fastening structure of this embodiment described above, regardless of the material combination of the first busbar 10 and the second busbar 20, which are made of a hard metal material (copper or copper alloy) having an oxide film, or aluminum material having a hard and thick oxide film, the oxide film on the joint surfaces 13 and 23 of the first busbar 10 and the second busbar 20 is reliably destroyed when bolted, enabling metal adhesion and thus obtaining stable electrical contact reliability.

[0045] Furthermore, in the busbar fastening structure of this embodiment, the range 60 corresponding to the seating surface 31 of the bolt 30 is set to be greater than or equal to the range having an outer diameter dimension obtained by adding the axial misalignment width of the first bolt through hole 11 to the outer diameter of the seating surface 31 of the bolt 30, and the range corresponding to the seating surface 41 of the nut 40 is set to be greater than or equal to the range having an outer diameter dimension obtained by adding the axial misalignment width of the second bolt through hole 21 to the outer diameter of the seating surface 41 of the nut 40.

[0046] Therefore, even if a misalignment occurs in the set position of the first busbar 10 and the second busbar 20, where the joint surface 13 and the joint surface 23 are superimposed, the number of intersection points 50 where the first protrusion 17 and the second protrusion 27 meet directly below the seating surface 31 of the bolt 30 and the seating surface 41 of the nut 40 (contact area) does not change significantly. Consequently, even when tightening torque is applied by bolt fastening, the surface pressure acting on the contact interface between the joint surface 13 and the joint surface 23 does not change significantly, and the oxide film can be reliably destroyed.

[0047] Furthermore, in the busbar fastening structure of this embodiment, a plurality of first protrusions 17 are formed parallel to the longitudinal direction of the first busbar 10 and at equal intervals from each other, and a plurality of second protrusions 27 are formed parallel to the short direction of the second busbar 20 and at equal intervals from each other.

[0048] Therefore, when the joint surface 13 of the first busbar 10 and the joint surface 23 of the second busbar 20 are positioned in contact, the first protrusion 17 and the second protrusion 27, which are in opposite directions (orthogonal directions), come into contact, and the contact points between the first protrusion 17 and the second protrusion 27 become the intersection points 50 of multiple squares aligned vertically and horizontally. Consequently, when tightening torque is applied by bolt fastening, the surface pressure acting on the contact interface between the joint surface 13 and the joint surface 23 can be evenly distributed.

[0049] Furthermore, in the busbar fastening structure of this embodiment, the multiple first protrusions 17 are formed by multiple grooves 15 recessed in the joining surface 13 of the first busbar 10, and the multiple second protrusions 27 are formed by multiple grooves 25 recessed in the joining surface 23 of the second busbar 20.

[0050] Therefore, since these multiple grooves 15 and 25 can be formed together during the press working process in the molding of the first busbar 10 and the second busbar 20, multiple first protrusions 17 and second protrusions 27 can be easily formed.

[0051] Therefore, regardless of the material combination of the first busbar 10 and the second busbar 20, a busbar fastening structure that can obtain stable electrical contact reliability can be provided.

[0052] (modified version) Figure 6 is a schematic exploded perspective view illustrating a modified busbar fastening structure according to this embodiment.

[0053] As shown in Figure 6, in the modified busbar fastening structure of this embodiment, a first busbar 10A and a second busbar 20A, which are formed in a flat, strip-shaped cross-section, are fastened and fixed together by bolts 30 and nuts 40.

[0054] In this embodiment, the joint surface 13 of the first busbar 10A has a plurality of (eight in this embodiment) first protrusions 17A formed around the first bolt through hole 11. The plurality of first protrusions 17A are formed parallel to the longitudinal direction of the first busbar 10A and at equal intervals from each other. These plurality of first protrusions 17A are composed of a plurality of (nine in this embodiment) grooves 15A recessed in the joint surface 13 of the first busbar 10A.

[0055] These multiple grooves 15A have a V-shaped cross-section, and the groove depth is at least deeper than the surface roughness and rolling scratches of the joint surface 13. Therefore, the first protrusion 17A, which is composed of multiple grooves 15A, has a trapezoidal cross-section.

[0056] Furthermore, multiple (10 in this embodiment) second protrusions 27A are formed on the joint surface 23 of the second busbar 20A around the second bolt through hole 21. These multiple second protrusions 27A are formed parallel to the short side of the second busbar 20A and at equal intervals from each other. These multiple second protrusions 27A are composed of multiple (11 in this embodiment) grooves 25A recessed in the joint surface 23 of the second busbar 20A.

[0057] These multiple grooves 25A have a V-shaped cross-section, and the groove depth is at least deeper than the surface roughness and rolling scratches of the joint surface 23. Therefore, the second protrusion 27A, which is composed of multiple grooves 25A, has a trapezoidal cross-section.

[0058] When the joint surface 13, which has multiple first protrusions 17A formed thereon, and the joint surface 23, which has multiple second protrusions 27A formed thereon, are arranged in a direction that brings them into contact, the first protrusions 17A and the second protrusions 27A, which are in opposite directions (orthogonal directions), come into contact with each other around the first bolt through-hole 11 and the second bolt through-hole 21. The contact points between these first protrusions 17A and second protrusions 27A form the intersection points 50 of multiple squares aligned vertically and horizontally (see Figure 4(b)).

[0059] According to the busbar fastening structure of the modified embodiment described above, similar to the busbar fastening structure of the above embodiment, regardless of the material combination or positional misalignment between the first busbar 10A and the second busbar 20A, which are made of a hard metal material (copper or copper alloy) having an oxide film, or aluminum material having a hard and thick oxide film, the oxide film on the joint surfaces 13, 23 of the first busbar 10A and the second busbar 20A is reliably destroyed during bolt fastening, enabling metal adhesion and thus obtaining stable electrical contact reliability.

[0060] Figure 7 is an enlarged view of the main parts of the first busbar 10B and the second busbar 20B, which are other modified examples of this embodiment, as viewed from the joint surfaces 13 and 23, respectively.

[0061] As shown in Figure 7, in another modification of this embodiment, the joint surface 13 of the first busbar 10B has a plurality of (12 in this embodiment) first protrusions 17B formed around the first bolt through hole 11. The plurality of first protrusions 17B are formed parallel to each other and at equal intervals along a direction that intersects the longitudinal direction of the first busbar 10A at a 45-degree angle. These plurality of first protrusions 17B are composed of a plurality of (13 in this embodiment) grooves 15B recessed in the joint surface 13 of the first busbar 10B.

[0062] These multiple grooves 15B have a rectangular cross-sectional shape, and the groove depth is at least deeper than the surface roughness and rolling scratches of the joint surface 13. Therefore, the first protrusion 17B, which is composed of multiple grooves 15B, has a rectangular cross-sectional shape.

[0063] Furthermore, multiple (12 in this embodiment) second protrusions 27B are formed on the joint surface 23 of the second busbar 20B around the second bolt through hole 21. These multiple second protrusions 27B are formed parallel to each other and at equal intervals along a direction that intersects the longitudinal direction of the second busbar 20B at a 45-degree angle. These multiple second protrusions 27B are composed of multiple (13 in this embodiment) grooves 25B recessed in the joint surface 23 of the second busbar 20B.

[0064] These multiple grooves 25B have a rectangular cross-sectional shape, and the groove depth is made deeper than the surface roughness and rolling scratches of the joint surface 23. Therefore, the second protrusion 27B, which is composed of multiple grooves 25B, has a rectangular cross-sectional shape.

[0065] When the joint surface 13, which has multiple first protrusions 17B formed thereon, and the joint surface 23, which has multiple second protrusions 27B formed thereon, are arranged in a direction that brings them into contact, the first protrusions 17B and the second protrusions 27B, which are in opposite directions (orthogonal directions), come into contact with each other around the first bolt through-hole 11 and the second bolt through-hole 21. The contact points between these first protrusions 17B and second protrusions 27B form the intersection points 50 of multiple rhombuses aligned vertically and horizontally (see Figure 4(b)).

[0066] According to the first busbar 10B and second busbar 20B, which are other modifications of the embodiment described above, regardless of the material combination or positional misalignment between the first busbar 10B and the second busbar 20B, which are made of a hard metal material (copper or copper alloy) having an oxide film, or an aluminum material having a hard and thick oxide film, the oxide film on the joint surfaces 13 and 23 of the first busbar 10B and the second busbar 20B is reliably destroyed during bolt fastening, enabling metal adhesion and thus obtaining stable electrical contact reliability.

[0067] Furthermore, according to the first busbar 10B and second busbar 20B according to other modifications of this embodiment, the multiple grooves 15B recessed in the joint surface 13 of the first busbar 10B and the multiple grooves 25B recessed in the joint surface 23 of the second busbar 20B have the same shape. Therefore, the press die used when press-forming the multiple grooves 15B and the multiple grooves 25B can be shared. Moreover, if the external shapes of the first busbar 10B and the second busbar 20B are the same, the first busbar 10B and the second busbar 20B can be made into common parts.

[0068] Furthermore, the present invention is not limited to the embodiments described above, and can be modified, improved, etc., as appropriate. In addition, the material, shape, dimensions, number, placement, etc. of each component in the embodiments described above are arbitrary and not limited, as long as they can achieve the present invention.

[0069] In the embodiments described above, the multiple first protrusions 17, 17A, 17B and the second protrusions 27, 27A, 27B are formed in a linear shape, extending parallel to each other at equal intervals. However, the multiple first and second protrusions of the present invention are not limited to these, and it goes without saying that they can take various forms in accordance with the spirit of the present invention. For example, the multiple first protrusions may be formed to extend radially from the center of the first bolt through hole, and the multiple second protrusions may be formed concentrically with the second bolt through hole.

[0070] Here, the features of the busbar fastening structure according to the present invention described above are briefly summarized and listed below in [1] to [4].

[0071] [1] First busbars (10, 10A, 10B) and second busbars (20, 20A, 20B) are fastened and secured by bolts (30) and nuts (40), Multiple first protrusions (17, 17A, 17B) are formed on the joint surface (13) of the first busbar (10, 10A, 10B) in a range (60) corresponding to at least the seat surface (31) of the bolt (30) in the periphery of the first bolt through hole (11), The device comprises a plurality of second protrusions (27, 27A, 27B) formed on the joint surface (23) of the second busbar (20, 20A, 20B) in a range (60) corresponding to at least the seating surface (41) of the nut (40) in the periphery of the second bolt through hole (21), In a state where the first busbars (10, 10A, 10B) and the second busbars (20, 20A, 20B) are fastened and fixed together, the plurality of first protrusions (17, 17A, 17B) and the plurality of second protrusions (27, 27A, 27B) intersect each other. Busbar fastening structure.

[0072] According to the busbar fastening structure described in [1] above, the contact points where the multiple first protrusions (17, 17A, 17B) and the second protrusions (27, 27A, 27B) intersect each other form multiple intersection points (50).

[0073] When the bolt 30 and nut 40 are fastened together, stress is transmitted from the seating surface (31) of the bolt (30) to the contact surface of the intersection (50) at the joint surface (13) and the joint surface (23) via the seating surface (31) of the bolt (30) and the seating surface (41) of the nut (40). Since the contact area between the joint surface (13) and the joint surface (23) that contact at multiple intersection (50) is reduced compared to the contact area between conventional flat joint surfaces, the surface pressure acting on the contact interface is improved even when the same tightening torque as in the past is applied.

[0074] Furthermore, as stress is transmitted to the contact surface of the aforementioned intersection (50), the first busbars (10, 10A, 10B) and the second busbars (20, 20A, 20B) are extended in the circumferential direction of the bolt (30), and parts of the plastically deformed first protrusions (17, 17A, 17B) and second protrusions (27, 27A, 27B) enter into multiple grooves (15, 15A, 15B, 25, 25A, 25B) at the contact interface.

[0075] Then, through a process in which parts of the plastically deformed first ridges (17, 17A, 17B) and second ridges (27, 27A, 27B) enter multiple grooves (15, 15A, 15B, 25, 25A, 25B), the oxide film (insulator) on the joint surface (13) of the first busbar (10, 10A, 10B) and the joint surface (23) of the second busbar (20, 20A, 20B) is destroyed, and the metals are joined (adhered) to each other.

[0076] Therefore, with this busbar fastening structure, regardless of the material combination of the first busbar (10, 10A, 10B) and the second busbar (20, 20A, 20B), which are made of a hard metal material (copper or copper alloy) having an oxide film, or aluminum material having a hard and thick oxide film, the oxide film on the joint surfaces (13, 23) of the first busbar (10, 10A, 10B) and the second busbar (20, 20A, 20B) is reliably destroyed during bolt fastening, allowing for metal adhesion and thus providing stable electrical contact reliability.

[0077] [2] The range (60) corresponding to the seating surface (31) of the bolt (30) is greater than or equal to the range having an outer diameter dimension obtained by adding the axial misalignment width of the first bolt through hole (11) to the outer diameter of the seating surface (31) of the bolt (30), The range (60) corresponding to the seating surface (41) of the nut (40) is set to be greater than or equal to the range having an outer diameter dimension obtained by adding the axial misalignment width of the second bolt through hole (21) to the outer diameter of the seating surface (41) of the nut (40). The busbar fastening structure described in [1] above.

[0078] According to the busbar fastening structure described in [2] above, even if a misalignment occurs in the set position of the first busbars (10, 10A, 10B) and the second busbars (20, 20A, 20B) whose joint surfaces (13) and joint surfaces (23) are superimposed, the number of intersection points (50) where the first protrusions (17, 17A, 17B) and the second protrusions (27, 27A, 27B) meet directly below the seating surfaces (31) of the bolts (30) and the seating surface (41) of the nuts (40) does not change significantly. Therefore, even when tightening torque is applied by bolt fastening, the surface pressure acting on the contact interface between the joint surfaces (13) and the joint surfaces (23) does not change significantly, and the oxide film can be reliably destroyed.

[0079] [3] The plurality of first protrusions (17, 17A) are formed parallel to the longitudinal direction of the first busbar (10, 10A) and at equal intervals from one another. The plurality of second protrusions (27, 27A) are formed parallel to the short direction of the second busbar (20, 20A) and at equal intervals from one another. The busbar fastening structure described in [1] or [2] above.

[0080] According to the busbar fastening structure described in [3] above, when the joint surface (13) of the first busbar (10, 10A) and the joint surface (23) of the second busbar (20, 20A) are arranged in a direction in which they are in contact, the first protrusions (17, 17A) and the second protrusions (27, 27A) which are in different directions (orthogonal directions) come into contact, and the contact points between these first protrusions (17, 17A) and second protrusions (27, 27A) become multiple intersection points (50) aligned vertically and horizontally. Therefore, when tightening torque is applied by bolt fastening, the surface pressure acting on the contact interface between the joint surface (13) and the joint surface (23) can be evenly distributed.

[0081] [4] The plurality of first protrusions (17, 17A) are formed by a plurality of grooves (15, 15A) recessed in the joint surface (13) of the first bus bar (10, 10A), The plurality of second protrusions (27, 27A) are formed by a plurality of grooves (25, 25A) recessed in the joint surface (23) of the second busbar (20, 20A). The bus bar fastening structure described in [3] above.

[0082] According to the busbar fastening structure described in [4] above, these multiple grooves (15, 15A, 25, 25A) can be formed together during the press working process in the forming of the first busbar (10, 10A) and the second busbar (20, 20A), respectively, so that multiple first protrusions (17, 17A) and second protrusions (27, 27A) can be easily formed. [Explanation of Symbols]

[0083] 10…First bus bar 11…First bolt through hole 13…Joint surface 17…First protrusion 20... Second bus bar 21...Second bolt through hole 23…Joint surface 27…Second protrusion 30... Volts 31...Seat 40... Nut 41...Seat

Claims

1. A first busbar and a second busbar are fastened and secured by bolts and nuts, A plurality of first protrusions are formed on the joint surface of the first busbar in an area corresponding to at least the seating surface of the bolt in the periphery of the first bolt through hole, The second busbar has a plurality of second protrusions formed on its joint surface in an area corresponding to at least the seating surface of the nut in the periphery of the second bolt through hole, In a state in which the first busbar and the second busbar are fastened and fixed together, the plurality of first protrusions and the plurality of second protrusions intersect each other. Busbar fastening structure.

2. The area corresponding to the seating surface of the bolt is set to be greater than or equal to the area having an outer diameter dimension obtained by adding the axial misalignment width of the first bolt through hole to the outer diameter of the seating surface of the bolt. The area corresponding to the seating surface of the nut is set to be greater than or equal to the area having an outer diameter dimension obtained by adding the axial misalignment width of the second bolt through hole to the outer diameter of the seating surface of the nut. The busbar fastening structure according to claim 1.

3. The plurality of first protrusions are formed parallel to the longitudinal direction of the first busbar and at equal intervals from one another. The plurality of second protrusions are formed parallel to the short direction of the second busbar and at equal intervals from one another. The busbar fastening structure according to claim 1 or 2.

4. The plurality of first protrusions are formed by a plurality of grooves recessed in the joint surface of the first busbar, The plurality of second protrusions are formed by a plurality of grooves recessed in the joint surface of the second busbar. The busbar fastening structure according to claim 3.

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