Bus bar and wiring module

Abstract

To reduce heat generation from a bus bar.SOLUTION: A bus bar 10 includes two connection portions 11 and a connecting portion 12 that connects and electrically connects the two connection portions 11, the connecting portion 12 including a first connecting portion 12A and a second connecting portion 12B different from the first connecting portion 12A, the first connecting portion 12A and the second connecting portion 12B are configured to be elastically deformable, the connecting portion 12 forms a conductive path between the two connection portions 11, and the cross-sectional area of the connecting portion 12 perpendicular to the conductive path is set to be larger than the cross-sectional area of the connecting portion 11 perpendicular to the arrangement direction of the two connection portions 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a bus bar and a wiring module. [Background technology]

[0002] An energy storage module for an electric vehicle, a hybrid vehicle, or the like includes a large number of stacked energy storage elements, and the energy storage elements are electrically connected in series or parallel by a bus bar. A connection bus bar described in JP 2019-207825 A (Patent Document 1 below) is known as such a bus bar. The connection bus bar has a plurality of plate-shaped connection parts that are connected to the electrode terminals of the energy storage elements. The connection parts are arranged in the left-right direction (long side direction of the connection bus bar). A bent part that protrudes in a direction away from the electrode terminal (upward) is formed between the plurality of connection parts in the connection bus bar. The bent part is configured to be able to be flexibly deformed in the long side direction of the connection bus bar. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-207825 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned connection busbar, the connection portions are directly connected to the electrode terminals of the energy storage elements, and adjacent connection portions are connected by bent portions. Therefore, when the energy storage module is used, a large current flows mainly through the bent portions. Therefore, it is considered that the amount of heat generated in the connection busbar, particularly in the bent portions, becomes excessive as the capacity of the energy storage elements increases and the size of the connection busbar decreases. [Means for solving the problem]

[0005] The busbar disclosed herein comprises two connection portions and a connecting portion that connects and electrically connects the two connection portions, the connecting portion comprising a first connecting portion and a second connecting portion different from the first connecting portion, the first connecting portion and the second connecting portion being configured to be elastically deformable, the connecting portion forming a conductive path between the two connection portions, and a cross-sectional area of ​​the connecting portion perpendicular to the conductive path is set to be larger than a cross-sectional area of ​​the connecting portion perpendicular to the arrangement direction of the two connection portions.

[0006] In addition, the wiring module of the present disclosure is a wiring module that is attached to a plurality of energy storage elements each having an electrode terminal, and includes the above-mentioned bus bar, the connection portion of which is connected to the electrode terminal, a voltage detection wire electrically connected to the bus bar, and a protector that holds the bus bar and the voltage detection wire. Effect of the Invention

[0007] According to the present disclosure, the amount of heat generated by the bus bar can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a bus bar according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the bus bar according to the first embodiment. [Diagram 3] FIG. 3 is a front view of the bus bar according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA of FIG. [Diagram 5] FIG. 5 is a plan view of the electricity storage module according to the first embodiment. [Figure 6] FIG. 6 is a perspective view of a bus bar according to a modified example of the first embodiment. [Figure 7] FIG. 7 is a perspective view of the bus bar according to the second embodiment. [Figure 8] FIG. 8 is an exploded perspective view of the bus bar according to the second embodiment. [Figure 9]FIG. 9 is a cross-sectional view of the electricity storage module according to the second embodiment, taken along the arrangement direction of the bus bars. [Figure 10] FIG. 10 is a perspective view of a bus bar according to a modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described. [1] The busbar disclosed herein comprises two connection portions and a connecting portion that connects and electrically connects the two connection portions, the connecting portions comprising a first connecting portion and a second connecting portion different from the first connecting portion, the first connecting portion and the second connecting portion being configured to be elastically deformable, the connecting portions forming a conductive path between the two connection portions, and a cross-sectional area of ​​the connecting portion perpendicular to the conductive path is set to be larger than a cross-sectional area of ​​the connecting portion perpendicular to the arrangement direction of the two connection portions.

[0010] According to this configuration, the cross-sectional area of ​​the connecting portion that connects the two connecting portions is set to be larger than the cross-sectional area of ​​the connecting portion, so that heat generation in the connecting portion can be easily suppressed.

[0011] [2] In the above item [1], it is preferable that a gap is formed between the first connecting portion and the second connecting portion.

[0012] With this configuration, compared to when the first connecting portion and the second connecting portion are arranged overlapping each other, the first connecting portion and the second connecting portion are each more likely to transfer heat to the surrounding air, making it easier for the first connecting portion and the second connecting portion to dissipate heat.

[0013] [3] The wiring module of the present disclosure is a wiring module attached to a plurality of energy storage elements each having an electrode terminal, and includes a bus bar as described above in [1] or [2], the connection portion of which is connected to the electrode terminal, a voltage detection wire electrically connected to the bus bar, and a protector that holds the bus bar and the voltage detection wire.

[0014] [Details of the embodiment of the present disclosure] The following describes embodiments of the present disclosure. The present disclosure is not limited to these examples, but is shown by the claims, and is intended to include all modifications within the meaning and scope of the claims. In each drawing, for convenience of explanation, some of the configurations may be exaggerated or simplified. In addition, the dimensional ratios of each part may differ in each drawing. In this specification, "orthogonal" does not only mean strictly orthogonal, but also includes roughly orthogonal within the range in which the action and effect of this embodiment are achieved.

[0015] In addition, "facing" in this specification refers to surfaces or members 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 member other than the two parts is interposed between the two parts, and cases where nothing is interposed between the two parts.

[0016] In each drawing, three mutually perpendicular directions are shown as a first direction D1, a second direction D2, and a third direction D3. That is, the first direction D1 and the second direction D2 are mutually perpendicular, the first direction D1 and the third direction D3 are mutually perpendicular, and the second direction D2 and the third direction D3 are mutually perpendicular. By showing arrows on both sides of the solid line indicating each direction, not only the direction of the arrow on the side with the symbol, but also the direction of the arrow on the side without the symbol is considered to indicate the corresponding direction.

[0017] <Embodiment 1> A first embodiment of the present disclosure will be described with reference to Figures 1 to 5. In the following description, for multiple identical members, only some of the members may be labeled with reference numerals, and the reference numerals of the other members may be omitted.

[0018] (Busbar 10) The busbar 10 is formed by processing a conductive metal plate material. The metal constituting the busbar 10 is, for example, copper, a copper alloy, aluminum, an aluminum alloy, etc. As shown in Fig. 2, the busbar 10 of this embodiment is composed of a first member 10A and a second member 10B that are separate from each other. The configurations of the first member 10A and the second member 10B will be described later.

[0019] 1, busbar 10 includes two connection portions 11 and a coupling portion 12 that couples and electrically connects the two connection portions 11. Below, the configuration of busbar 10 will be described, assuming that the arrangement direction of the two connection portions 11 (the long side direction of busbar 10) is a first direction D1, the width direction (short side direction) of busbar 10 is a second direction D2, and the thickness direction of connection portions 11 is a third direction D3.

[0020] The connection portion 11 has a thin plate shape in the third direction D3. The connection portion 11 has, for example, a rectangular shape when viewed from the third direction D3. The two connection portions 11 are arranged side by side with a gap in the first direction D1. A through hole 11A is formed in the center of the connection portion 11. The through hole 11A penetrates the connection portion 11 in the third direction D3. As described later, the connection portion 11 is connected to the electrode terminal 2A of the energy storage element 2 by, for example, welding or the like (see FIG. 5). The through hole 11A is used to confirm the position of the electrode terminal 2A arranged opposite the connection portion 11 in the third direction D3. Note that, unlike this embodiment, the connection portion may have, for example, an insertion hole into which a bolt-shaped electrode terminal is inserted. The connection portion and the electrode terminal may be electrically connected by fastening a nut to the electrode terminal inserted into the insertion hole.

[0021] 1 and 3, the connecting portion 12 includes a first connecting portion 12A and a second connecting portion 12B different from the first connecting portion 12A. The first connecting portion 12A and the second connecting portion 12B each connect and electrically connect two connecting portions 11. At least one of the first connecting portion 12A and the second connecting portion 12B and the two connecting portions 11 form a plate shape that is continuous in the arrangement direction of the two connecting portions 11 (first direction D1). For example, the first connecting portion 12A and the two connecting portions 11 form a seamless plate shape that is continuous in the first direction D1.

[0022] The conductive path between the two connection parts 11 formed by the coupling part 12 includes a first conductive path formed by the first coupling part 12A and a second conductive path different from the first conductive path and formed by the second coupling part 12B. Note that the first conductive path and the second conductive path may have paths that partially overlap each other.

[0023] As shown in FIG. 4, the dimensions (width dimensions) of the first connecting portion 12A and the second connecting portion 12B in the second direction D2 are, for example, the same and are equal to the width dimension of the connection portion 11. As shown in FIG. 3, the first connecting portion 12A and the second connecting portion 12B are arranged, for example, overlapping in the third direction D3. In this embodiment, a gap 13 is formed between the first connecting portion 12A and the second connecting portion 12B. By providing the gap 13, the first connecting portion 12A and the second connecting portion 12B are arranged spaced apart from each other. The gap 13 is provided to open in the second direction D2. In other words, the gap 13 is not defined in the second direction D2.

[0024] The first connecting portion 12A and the second connecting portion 13B are, for example, plate-shaped and bent with respect to the connecting portion 11 so as to protrude in the second direction D2. The first connecting portion 12A and the second connecting portion 12B are formed in a mountain shape with respect to the connecting portion 11. This allows the first connecting portion 12A and the second connecting portion 12B to be elastically deformable. Furthermore, by providing a gap 13 between the first connecting portion 12A and the second connecting portion 12B, the first connecting portion 12A and the second connecting portion 12B do not interfere with each other and can be elastically deformed independently.

[0025] The first connecting portion 12A and the second connecting portion 12B are elastically deformed to allow a certain degree of relative displacement of the two connecting portions 11. The first connecting portion 12A and the second connecting portion 12B can allow relative displacement in the arrangement direction (first direction D1) of the two connecting portions 11. The first connecting portion 12A and the second connecting portion 12B can also allow relative displacement in the thickness direction (third direction D3) of the two connecting portions 11.

[0026] In this embodiment, the first coupling portion 12A and the second coupling portion 12B are configured to protrude in the same direction (upward in FIG. 3) in the third direction D3 with respect to the connection portion 11. With this configuration, it is possible to reduce the dimension of the busbar 10 in the third direction D3.

[0027] FIG. 4 shows a cross section of the coupling portion 12 and the connecting portion 11, which is perpendicular to the first direction D1. The cross-sectional area S1 of the coupling portion 12 is composed of the cross-sectional area S1A of the first connecting portion 12A and the cross-sectional area S1B of the second connecting portion 12B. Here, the thickness of the connecting portion 11 and the first connecting portion 12A are the same. The width dimensions of the connecting portion 11 and the first connecting portion 12A are the same. Therefore, the cross-sectional area S2 of the connecting portion 11 is equal to the cross-sectional area S1A of the first connecting portion 12A. Therefore, the cross-sectional area S1 of the coupling portion 12 is larger than the cross-sectional area S2 of the connecting portion 11. Note that in this specification, the cross-sectional area S1 of the coupling portion 12 does not have to be the area of ​​a cross section perpendicular to the first direction D1 (arrangement direction of the connecting portions 11), but may be the area of ​​a cross section perpendicular to the conductive path formed by the coupling portion 12, including the cross section of the first connecting portion 12A and the cross section of the second connecting portion 12B. The cross-sectional area S2 of the connection portion 11 is limited to the area of ​​a cross section perpendicular to the first direction D1.

[0028] As shown in FIG. 2, the first member 10A and the second member 10B are each formed by bending a metal plate material. The width dimensions of the first member 10A and the second member 10B are, for example, the same. The thicknesses of the first member 10A and the second member 10B may or may not be the same. The first member 10A has two connection parts 11 and a first coupling part 12A. The second member 10B has two joint parts 14 and a second coupling part 12B that couples the two joint parts 14. Each joint part 14 is joined to a part of each connection part 11 close to the first coupling part 12A by welding or the like.

[0029] (Wiring module 3) As shown in Fig. 5, the bus bar 10 of this embodiment is included in an energy storage module 1 mounted on a vehicle such as an electric vehicle or a hybrid vehicle. The energy storage module 1 includes a plurality of energy storage elements 2 each having an electrode terminal 2A, and a wiring module 3 attached to the plurality of energy storage elements 2. The wiring module 3 includes the bus bar 10, a flexible printed circuit board 20 (an example of a voltage detection line) electrically connected to the bus bar 10, and a protector 30 that holds the bus bar 10 and the flexible printed circuit board 20. For simplicity, the configuration of the energy storage module 1 (the energy storage elements 2 and the wiring module 3) will be described below with the lower side in Fig. 5 as the front, the upper side as the rear, the left-right directions as the left-right directions, and the front side in the direction perpendicular to the paper surface as the top.

[0030] The energy storage element 2 has a rectangular parallelepiped shape. The energy storage element 2 is thin in the left-right direction and long in the front-rear direction. Electrode terminals 2A are provided at the front and rear ends of the upper surface of the energy storage element 2. One of the two electrode terminals 2A of the energy storage element 2 is a positive electrode, and the other is a negative electrode. The energy storage element 2 is not particularly limited, and may be a secondary battery or a capacitor. The energy storage element 2 in this embodiment is a secondary battery. A plurality of energy storage elements 2 are stacked in the left-right direction. A spacer (not shown) is arranged between adjacent energy storage elements 2.

[0031] The wiring module 3 is attached to the front and rear portions of the upper surfaces of the multiple energy storage elements 2. Fig. 5 illustrates the wiring module 3 attached to the front portions of the upper surfaces of the multiple energy storage elements 2. The wiring module 3 attached to the rear portions of the upper surfaces of the multiple energy storage elements 2 is not illustrated, but is configured similarly to the wiring module 3 illustrated in Fig. 5.

[0032] The protector 30 is made of an insulating synthetic resin. The protector 30 includes a busbar accommodating section 31 in which the busbar 10 is accommodated, and a board accommodating section 32 in which the flexible printed circuit board 20 is accommodated. The busbar accommodating section 31 is frame-shaped and arranged side by side in the left-right direction. A connection hole (not shown) is provided in the bottom wall of the busbar accommodating section 31. The connection section 11 of the busbar 10 is connected to the electrode terminal 2A through this connection hole. The board accommodating section 32 is in the shape of a groove extending in the left-right direction. The board accommodating section 32 is disposed behind the busbar accommodating section 31. A cutout section 31A is formed in a wall section of the busbar accommodating section 31 that is disposed closer to the board accommodating section 32. A metal piece 40 that electrically connects the busbar 10 and the flexible printed circuit board 20 is disposed in the cutout section 31A. The metal piece 40 and the busbar 10 are connected by, for example, welding. The metal piece 40 and the flexible printed circuit board 20 are connected by, for example, soldering. The wiring module 3 may include a cover (not shown) that covers the protector 30 that holds the bus bar 10 and the flexible printed circuit board 20.

[0033] The flexible printed circuit board 20 includes a sheet-like member made of insulating synthetic resin, and a plurality of conductive paths protected by the sheet-like member. One end of the conductive path is electrically connected to the bus bar 10 via a metal piece 40. The other end of the conductive path is connected to an external ECU (Electronic Control Unit) or the like via a connector (not shown). The ECU is equipped with a microcomputer, elements, etc., and has a well-known configuration having functions for detecting the voltage, current, temperature, etc. of each storage element 2, controlling the charging and discharging of each storage element 2, etc.

[0034] In the wiring module 3, the connection portion 11 of the busbar 10 is disposed to face the electrode terminal 2A, and the connection portion 11 and the electrode terminal 2A are connected by welding. The linking portion 12 extends in a direction away from the energy storage element 2 in the thickness direction (third direction D3) of the linking portion 11. The busbar 10 connects between the electrode terminals 2A of the adjacent energy storage elements 2. That is, the linking portion 12 forms a conductive path between the two linking portions 11. For this reason, a large current flows through the linking portion 12 when the vehicle is in use. In this embodiment, as described above, the cross-sectional area S1 of the linking portion 12 is set to be larger than the cross-sectional area S2 of the connection portion 11. Therefore, compared to a case where, for example, the busbar is formed by processing a single metal plate material and the cross-sectional area of ​​the linking portion is the same as the cross-sectional area of ​​the connection portion, heat generation in the linking portion 12 can be suppressed. Since the linking portion 12 is a portion of the busbar 10 that is particularly prone to heat generation, heat generation in the busbar 10 can be suppressed according to this embodiment. Since the connection portion 11 is directly connected to the electrode terminal 2A, heat can be transferred from the connection portion 11 to the electrode terminal 2A.

[0035] In this embodiment, since the gap 13 is formed between the first connecting portion 12A and the second connecting portion 12B, heat generated at the first connecting portion 12A and the second connecting portion 12B during use of the vehicle is transferred to the air disposed in the gap 13. As a result, the heat dissipation properties of the first connecting portion 12A and the second connecting portion 12B can be further improved.

[0036] In the busbar 10 of this embodiment, the elastic deformation of the coupling parts 12 allows the connection parts 11 to be displaced in the arrangement direction. Thus, according to the arrangement as shown in FIG. 5, the coupling parts 12 allow the connection parts 11 to be displaced in the left-right direction. Therefore, it is possible to absorb manufacturing tolerances and assembly tolerances in the left-right direction of the energy storage elements 2. Furthermore, even if adjacent energy storage elements 2 are dynamically displaced in the left-right direction due to vibration of the vehicle or the like, the elastic deformation of the coupling parts 12 makes it difficult for the connection parts 11 and the electrode terminals 2A to be damaged. Similarly, the coupling parts 12 can allow the connection parts 11 to be displaced in the thickness direction of the connection parts 11, so that the arrangement shown in FIG. 5 allows tolerances and fluctuations in the up-down direction of the energy storage elements 2.

[0037] (Effects of the First Embodiment) (1-1) The busbar 10 in embodiment 1 comprises two connection portions 11 and a connecting portion 12 that connects and electrically connects the two connection portions 11, the connecting portion 12 comprises a first connecting portion 12A and a second connecting portion 12B different from the first connecting portion 12A, the first connecting portion 12A and the second connecting portion 12B are configured to be elastically deformable, the connecting portion 12 forms a conductive path between the two connection portions 11, and a cross-sectional area S1 of the connecting portion 12 perpendicular to the conductive path is set to be larger than a cross-sectional area S2 of the connecting portion 11 perpendicular to the arrangement direction of the two connection portions 11.

[0038] According to this configuration, the cross-sectional area S1 of the connecting portion 12 connecting the two connecting portions 11 is set to be larger than the cross-sectional area S2 of the connecting portion 11, so that heat generation in the connecting portion 12 can be easily suppressed.

[0039] (1-2) In the first embodiment, a gap 13 is formed between the first connecting portion 12A and the second connecting portion 12B.

[0040] With this configuration, compared to when the first connecting portion 12A and the second connecting portion 12B are arranged so as to overlap, the first connecting portion 12A and the second connecting portion 12B are each more easily able to transfer heat to the surrounding air, making it easier for the first connecting portion 12A and the second connecting portion 12B to dissipate heat.

[0041] (1-3) The wiring module 3 of embodiment 1 is a wiring module 3 attached to a plurality of energy storage elements 2 each having an electrode terminal 2A, and includes a bus bar 10 having a connection portion 11 connected to the electrode terminal 2A, a voltage detection wire (flexible printed circuit board 20) electrically connected to the bus bar 10, and a protector 30 that holds the bus bar 10 and the voltage detection wire.

[0042] <Modification of the first embodiment> Fig. 6 shows a busbar 110 according to a modified example of the first embodiment. Although the busbar 10 is composed of a first member 10A and a second member 10B, a busbar according to the present disclosure may be composed of a single member, such as the busbar 110 in Fig. 6. That is, the first connecting portion 12A and the second connecting portion 12B may be integrally provided. The busbar 110 may be formed by, for example, extrusion molding.

[0043] <Embodiment 2> A second embodiment of the present disclosure will be described with reference to Fig. 7 to Fig. 9. A busbar 210 according to the second embodiment has a similar configuration to that of the first embodiment, except for the configuration of a connecting portion 212, and therefore descriptions of the same members, functions, and effects as those of the first embodiment may be omitted.

[0044] As shown in FIG. 7, the coupling portion 212 of the busbar 210 includes a first coupling portion 212A protruding from the connection portion 11 to one side (downward in the figure) in the third direction D3, and a second coupling portion 212B protruding from the connection portion 11 to the other side (downward in the figure) in the third direction D3. That is, the first coupling portion 212A and the second coupling portion 212B protrude in opposite directions from the connection portion 11. According to this configuration, it is easier to increase the gap 13 provided between the first coupling portion 212A and the second coupling portion 212B, compared to the form in which the first coupling portion 12A and the second coupling portion 12B protrude in the same direction from the connection portion 11 as in the first embodiment (see FIG. 3). Therefore, it is possible to receive even more air into the gap 13. This improves the heat dissipation properties of the first coupling portion 212A and the second coupling portion 212B.

[0045] In the second embodiment, as shown in FIG. 8, bus bar 210 is formed by joining first member 210A and second member 210B, similar to the first embodiment.

[0046] FIG. 9 shows a cross-sectional view of the wiring module 203 (and the energy storage module 201) including the bus bar 210 and the protector 230. Note that in FIG. 9, the voltage detection wire and the small metal pieces are omitted, and only the main parts of the protector 230 are shown. The wiring module 203 may be configured such that the first coupling portion 212A (or the second coupling portion 212B) of the bus bar 210 is disposed between the energy storage elements 2 adjacent to each other in the first direction D1. The protector 230 may have an accommodating recess 231A capable of accommodating the first coupling portion 212A. In the energy storage module 201, a spacer 204 may be provided between the two energy storage elements 2 in the first direction D1 while ensuring a space capable of arranging the accommodating recess 231A.

[0047] <Modification of the second embodiment> 10 shows a busbar 310 according to a modification of embodiment 2. Like busbar 110 according to the modification of embodiment 1, busbar 310 is formed from a single member by extrusion molding or the like.

[0048] (Other embodiments) The above-mentioned first and second embodiments can be modified as follows: The above-mentioned first and second embodiments and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0049] In the first embodiment, the bus bar 10 has the through hole 11A, but the through hole may be omitted.

[0050] In the above-described first embodiment, the flexible printed circuit board 20 is illustrated as the voltage detection wire, but the voltage detection wire may be an electric wire, a flexible flat cable, or the like.

[0051] In the first embodiment, the bus bar 10 and the flexible printed circuit board 20 are indirectly connected via the metal pieces 40, but the bus bar and the flexible printed circuit board may be directly connected. [Explanation of symbols]

[0052] 1: Energy storage module 2: Energy storage element 2A: Electrode terminal 3: Wiring module 10: Busbar 10A: First member 10B: Second member 11: Connection 11A:Through hole 12:Connection part 12A: 1st connection part 12B:Second connection part 13: Gap 13B:Second connection part 14:Joint part 20: Flexible printed circuit board (an example of a voltage detection line) 30: Protector 31: Busbar housing 31A: Notch 32: Substrate housing section 40: Small metal piece 110: Busbar 201: Energy storage module 203: Wiring module 204: Spacer 210: Busbar 210A: First member 210B: Second member 212:Connection part 212A: 1st connection part 212B:Second connection part 230: Protector 231A: Storage recess 310: Busbar D1: 1st direction D2:Second direction D3: Third direction S1: Cross-sectional area of ​​the connecting portion 12 S1A: Cross-sectional area of ​​the first connecting portion 12A S1B: Cross-sectional area of ​​the second connecting portion 12B S2: Cross-sectional area of ​​the connection part 11

Claims

1. Two connectors; a connecting portion that connects and electrically connects the two connecting portions, The connecting portion includes a first connecting portion and a second connecting portion different from the first connecting portion, The first connecting portion and the second connecting portion are configured to be elastically deformable, The coupling portion forms a conductive path between the two connection portions, A bus bar, wherein a cross-sectional area of ​​the coupling portion perpendicular to the conductive path is set to be larger than a cross-sectional area of ​​the connection portion perpendicular to an arrangement direction of the two connection portions.

2. The bus bar according to claim 1 , wherein a gap is formed between the first connecting portion and the second connecting portion.

3. A wiring module attached to a plurality of energy storage elements each having an electrode terminal, The bus bar according to claim 1 or 2, wherein the connection portion is connected to the electrode terminal; A voltage detection line electrically connected to the bus bar; a protector that holds the bus bar and the voltage detection line.

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