Bus bar module

Abstract

A bus bar module (10) includes: a first circuit body (20A) formed of a flexible substrate and including a first main line portion (21) and a first branch line portion (22); a second circuit body (20B) formed of a flexible substrate having a second wiring pattern (26) and including a second main line portion (21) and a second branch line portion (22); an electronic component (50); and a holder (60). The first and second wiring patterns (26) are electrically connected to each other at an overlapping portion (23) of the first and second main line portions (21).

Description

Technical Field

[0001] The invention relates to a busbar module. Background Art

[0002] In the related art, a bus bar module is used, for example, to be assembled to a battery assembly (ie, a battery module in which a plurality of battery cells are stacked and arranged) used as a driving power source mounted on an electric vehicle, a hybrid vehicle, etc. (eg, see Patent Document 1).

[0003] The bus bar module described in Patent Document 1 includes a plurality of bus bars and a voltage detection line. The bus bars are stacked, and each bus bar connects the positive and negative electrodes between adjacent battery cells. The voltage detection lines are respectively connected to the plurality of bus bars and monitor the battery cells. The voltage detection lines are configured to bundle a plurality of wires. Each wire has a general structure in which a core wire is covered with an insulating sheath.

[0004] Reference List

[0005] Patent Literature

[0006] Patent Document 1: JP2014-220128A Summary of the invention

[0007] Technical issues

[0008] Typically, the battery cells included in the battery assembly expand and contract in the stacking direction due to operational heat associated with charging and discharging, the temperature of the external environment, and the like. Therefore, the battery assembly (battery module) is also deformed to expand and contract in the stacking direction of the battery cells. In addition, when a plurality of battery cells are stacked and arranged, the size of the battery assembly in the stacking direction typically varies from one battery assembly to another due to assembly tolerances (i.e., manufacturing variations may occur). Therefore, the bus bar module is typically designed to have a certain margin in the length of the voltage detection line in order to cope with such deformation and manufacturing variations of the battery assembly.

[0009] However, in the bus bar module in the above-mentioned related art, for example, when the number of stacked battery cells is increased in order to increase the capacity of the battery assembly, the number of wires forming the voltage detection line also increases. Therefore, when the voltage detection line is formed by bundling these wires, the rigidity of the voltage detection line as a whole (and thus the rigidity of the bus bar module) increases, and it may be difficult to improve the operability (assemblyability) of assembling the bus bar module to the battery assembly. For the same reason, the bus bar module may also be difficult to extend and contract to fully cope with deformation and manufacturing variations of the battery assembly.

[0010] An object of the present invention is to provide a bus bar module which is excellent in assemblability to a battery assembly and adaptability to deformation and manufacturing variations of the battery assembly.

[0011] Solution to the problem

[0012] In order to achieve the above-mentioned object, a bus bar module according to an embodiment of the present invention is a bus bar module to be attached to a battery assembly in which a plurality of single cells are stacked, and includes:

[0013] a first circuit body formed of a flexible substrate having a first wiring pattern and including a first main line portion and a first branch line portion, the first main line portion being arranged to extend along a stacking direction of the plurality of battery cells and the first branch line portion branching from the first main line portion;

[0014] a second circuit body formed of a flexible substrate having a second wiring pattern and including a second main line portion arranged to extend in the stacking direction and a second branch line portion branching from the second main line portion;

[0015] a bus bar configured to be connected to adjacent electrodes between the plurality of cells;

[0016] electronic components each attached to the first branch line portion and the second branch line portion such that each electronic component connects the first wiring pattern and the second wiring pattern to the corresponding bus bar; and

[0017] A bracket, which can be extended and retracted along the stacking direction and holds the first circuit body, the second circuit body and the bus bar, wherein

[0018] The first wiring pattern and the second wiring pattern are electrically connected to each other at an overlapping portion of the first main line portion and the second main line portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a perspective view showing a bus bar module according to the present embodiment;

[0020] Figure 2 It shows Figure 1 A perspective view of a battery assembly into which the bus bar module is to be assembled is shown;

[0021] Figure 3 is shown when included in Figure 1 A perspective view showing a process in which a first circuit body and a second circuit body in the circuit body are connected and accommodated in a bracket;

[0022] Figure 4 It is shown that the Figure 1A perspective view showing a state in which a first circuit body and a second circuit body among the circuit bodies are connected and accommodated in a bracket;

[0023] Figure 5 is a perspective view showing first to third circuit bodies included in the circuit body according to the first modification (however, wiring patterns are not shown);

[0024] Figure 6 is a perspective view showing a state in which a connection portion of a first circuit body and a connection portion of a second circuit body included in a circuit body according to a second modification are connected; and

[0025] Figure 7 : is a perspective view showing a state in which a connection portion of a first circuit body and a connection portion of a second circuit body included in a circuit body according to a third modification are connected. DETAILED DESCRIPTION

[0026] Hereinafter, a bus bar module 10 according to an embodiment of the present invention will be described with reference to the accompanying drawings. The bus bar module 10 according to the present embodiment is used, for example, to be assembled to a long battery assembly 1 (a battery module in which a plurality of single cells are stacked and arranged, see Figure 2 ).

[0027] In the following, for the convenience of description, “front”, “rear”, “left”, “right”, “upper” and “lower” are defined as follows: Figure 1 The “front-rear direction”, “left-right direction” and “up-down direction” are orthogonal to each other. The front-rear direction is the stacking direction of the plurality of cells 2 included in the battery assembly 1 (see FIG. Figure 1 and 2 These directions are defined for convenience of description and do not necessarily correspond to the front-rear direction, left-right direction, and up-down direction of the vehicle when the bus bar module 10 is mounted on the vehicle.

[0028] First, as a preparation for describing the bus bar module 10, reference will be made to Figure 2 The battery assembly 1 to which the bus bar module 10 is to be attached is described. Figure 2 As shown, the battery assembly 1 is formed by stacking a plurality of rectangular flat-plate-shaped cells 2 in the front-to-rear direction, each of which extends in the up-down direction and the left-right direction. Each of the plurality of cells 2 includes a battery body 3 having a rectangular flat plate shape, and a positive electrode 4 and a negative electrode 5 protruding upward from both ends in the left-right direction of the upper surface 6 of the battery body 3.

[0029] In the battery assembly 1, by making the positions of the positive electrode 4 and the negative electrode 5 of a single cell 2 adjacent in the front-to-back direction in the left-to-right direction opposite to the positions of the positive electrode 4 and the negative electrode 5 of another single cell 2 in the left-to-right direction, a plurality of single cells 2 are stacked so that the positive electrode 4 and the negative electrode 5 are alternately arranged in the front-to-back direction at each of the left end portion and the right end portion of the upper surface of the battery assembly 1.

[0030] Hereinafter, the bus bar module 10 will be described. Figure 1 , 3 As shown in FIG. 4 , the bus bar module 10 includes a long circuit body 20 extending in the front-rear direction (see FIG. Figure 1 and 3 ), a plurality of branch line portions 22 connected to the circuit body 20 (see Figure 3 ) of a plurality of bus bars 40 (see Figure 1 ), a plurality of electronic components 50 mounted on a plurality of branch line portions 22 (see Figure 3 ), a bracket 60 for holding the circuit body 20 and the bus bar 40 (see Figure 1 and 3 ) and a cover 70 covering the circuit body 20 (see Figure 1 The main line portion 21 and the branch line portion 22 of the circuit body 20 (see Figure 3 ) are also called "main line" and "branch line" respectively.

[0031] The circuit body 20 is formed of a flexible substrate (FPC) that is easily bent. Figure 1 and Figure 3 It can be understood that the circuit body 20 includes a pair of left and right first circuit bodies 20A and a pair of left and right second circuit bodies 20B. The left and right first circuit bodies 20A extend in the front-to-back direction and are spaced apart in the left-to-right direction. The left and right second circuit bodies 20B are respectively connected to the rear sides of the pair of left and right first circuit bodies 20A and extend in the front-to-back direction. The pair of left and right first circuit bodies 20A and the pair of left and right second circuit bodies 20B are connected in the left-to-right direction by a connecting portion 28 (see FIG. Figure 1 ). Connector 29 (see FIG. 1 ) electrically connected to an external voltage detection device (not shown) or the like. Figure 1 ) is installed on the lower surface of the connecting portion 28.

[0032] Each of the first circuit body 20A and the second circuit body 20B includes a strip-shaped main line portion 21 extending in the front-rear direction, and at least one (in this example, a plurality of) branch line portions 22 extending to branch outward in the left-right direction from at least one (in this example, a plurality of) portions of the main line portion 21 in the front-rear direction (see Figure 3). In this example, the branch line portion 22 extends from the main line portion 21 in a manner having a U-shaped bend shape. Since the branch line portion 22 has a U-shaped bend shape, the flexibility of the branch line portion 22 in the front-back, left-right, and up-down directions is improved. The metal contact portion 24 is provided on the upper surface of the distal end portion of the branch line portion 22 to be exposed to the outside (see Figure 3 ).

[0033] The circuit body 20 is formed by connecting the circuit connection portion 23 provided at the rear end portion of the main line portion 21 of the first circuit body 20A and the circuit connection portion 23 provided at the front end portion of the main line portion 21 of the second circuit body 20B, wherein the main line portion 21 of the first circuit body 20A and the main line portion 21 of the second circuit body 20B extend continuously in a row in the front-rear direction. The detailed structure of the circuit connection portion 23 of each of the first circuit body 20A and the second circuit body 20B and the connection process between the circuit connection portions 23 will be described later.

[0034] The entire surface of each of the first circuit body 20A and the second circuit body 20B is formed of a resin layer except for a portion where the contact portion 24 provided on the branch line portion 22 is exposed (see Figure 3 ) and a portion where a contact portion 25 provided on a circuit connecting portion 23 described later is exposed (see Figure 3 Each of the first circuit body 20A and the second circuit body 20B includes a plurality of wiring patterns 26 (see Figure 3 ). The wiring pattern 26 is a copper conductor extending in a strip shape, and extends along the main line portion 21 and the branch line portion 22. Each of the first circuit body 20A and the second circuit body 20B is a so-called "single-sided flexible substrate (single-sided FPC)" having a single wiring layer. A plurality of wiring patterns 26 are arranged on a single wiring layer of each of the first circuit body 20A and the second circuit body 20B.

[0035] At the position where the circuit connecting portion 23 of the first circuit body 20A and the circuit connecting portion 23 of the second circuit body 20B are connected to each other, at least one (in this example, six) wiring patterns 26 belonging to the first circuit body 20A and at least one (in this example, six) wiring patterns 26 belonging to the second circuit body 20B are respectively and independently connected to each other (see Figure 3 ).

[0036] Each of the plurality of wiring patterns 26 included in the first circuit body 20A and the second circuit body 20B is electrically connected to the connector 29 mounted on the connecting portion 28 in sequence through the contact portion 24 of a corresponding one of the branch line portions 22, the corresponding branch line portion 22, the main line portion 21, and the connecting portion 28. Therefore, the contact portions 24 of the branch line portions 22 belonging to the first circuit body 20A and the second circuit body 20B are conductively connected individually to the external voltage detection device via the connector 29 mounted on the connecting portion 28.

[0037] The distal end portion of the branch line portion 22 is mounted with an electronic component 50 and is connected to an elongated flat plate-shaped metal connection terminal 41 connected to the bus bar 40 (see Figure 3 The connection terminal 41 may be a portion of a substantially rectangular flat plate-shaped metal bus bar 40 (see Figure 1 ), or may be a member that is a separate member from the bus bar 40 and is joined to the bus bar 40 by welding or the like. The electronic component 50 is typically a sheet fuse. The electronic component 50 is mounted on the distal end portion of the branch line portion 22 by welding or the like so as to connect the contact portion 24 of the branch line portion 22 with the connection terminal 41. Therefore, in the branch line portion 22, the contact portion 24 (i.e., the wiring pattern 26 extending from the contact portion 24) and the connection terminal 41 (i.e., the bus bar 40) are electrically connected via the electronic component 50.

[0038] In a state before the circuit connection portion 23 of the first circuit body 20A and the circuit connection portion 23 of the second circuit body 20B are connected to each other (i.e., in a state where each of the first circuit body 20A and the second circuit body 20B is independent), the mounting of the electronic component 50 on the branch line portion 22 is performed separately on the branch line portion 22 belonging to the first circuit body 20A and the branch line portion 22 belonging to the second circuit body 20B. Therefore, compared with the case where the first circuit body 20A and the second circuit body 20B are formed by a common (single) flexible substrate, the length of each of the first circuit body 20A and the second circuit body 20B in the front-back direction is shortened, so a large mounting device is not required. In other words, since the first circuit body 20A and the second circuit body 20B are separate bodies, regardless of the length and size of the long circuit body 20 obtained by connecting the circuit connection portion 23 of the first circuit body 20A and the circuit connection portion 23 of the second circuit body 20B to each other, the electronic component 50 can be appropriately mounted on the branch line portion 22, and the manufacturing cost of the bus bar module 10 can be reduced.

[0039] Hereinafter, the detailed structure of the circuit connection portion 23 of each of the first circuit body 20A and the second circuit body 20B and the connection process between the circuit connection portions 23 will be described. Figure 3As shown, on the upper surface of the circuit connection part 23 of the first circuit body 20A, a plurality of (in this example, six) metal contact parts (pads) 25 are arranged in a spaced manner in the front-to-back direction and exposed to the outside. Wiring patterns 26 extend from the contact parts 25, respectively. More specifically, for each of the three contact parts 25 on the front side (the proximal side of the circuit connection part 23) of the six contact parts 25, the wiring pattern 26 extends from the contact part 25 to one side (the left side) in the width direction (left-right direction) of the main line part 21 of the first circuit body 20A, and then extends forward. For each of the three contact parts 25 on the rear side (the far side of the circuit connection part 23) of the six contact parts 25, the wiring pattern 26 extends from the contact part 25 to the other side (the right side) in the width direction (left-right direction) of the main line part 21 of the first circuit body 20A, and then extends forward.

[0040] In this way, by arranging the extensions of the plurality of wiring patterns 26 extending from the plurality of contact portions 25 in a distributed manner in the left-right direction, it is possible to contribute to improving the degree of freedom of pattern design of the extensions of the wiring patterns 26 extending from the contact portions 25, miniaturization of the circuit connection portion 23 (i.e., the first circuit body 20A), etc. On the upper surface of the circuit connection portion 23 of the first circuit body 20A, a metal dummy contact portion (pad) 27 is arranged to be exposed to the outside at a position that does not interfere with the contact portion 25 and the wiring pattern 26. The dummy contact portion 27 is not connected (electrically connected) to the wiring pattern 26 (i.e., the bus bar 40). In the circuit connection portion 23 of the first circuit body 20A, hole portions 31 penetrating in the thickness direction (up and down direction) of the circuit connection portion 23 are respectively formed at a plurality of positions (in this example, two positions) that do not interfere with the contact portion 25, the wiring pattern 26, and the dummy contact portion 27.

[0041] On the lower surface of the circuit connection portion 23 of the second circuit body 20B, a plurality of (in this example, six) metal contact portions (pads) 25 are arranged in a spaced manner in the front-rear direction and exposed to the outside, and correspond to the plurality of contact portions 25 of the first circuit body 20A. Wiring patterns 26 extend from the contact portions 25, respectively. More specifically, for each of the three contact portions 25 on the front side (the distal side of the circuit connection portion 23) of the six contact portions 25, the wiring pattern 26 extends from the contact portion 25 to the other side (the right side) in the width direction (left-right direction) of the main line portion 21 of the second circuit body 20B, and then extends backward. For each of the three contact portions 25 on the rear side (the proximal side of the circuit connection portion 23) of the six contact portions 25, the wiring pattern 26 extends from the contact portion 25 to one side (the left side) in the width direction (left-right direction) of the main line portion 21 of the second circuit body 20B, and then extends backward.

[0042] In this way, by arranging the extensions of the plurality of wiring patterns 26 extending from the plurality of contact portions 25 in a distributed manner in the left-right direction, it is possible to contribute to improving the degree of freedom of pattern design of the extensions of the wiring patterns 26 extending from the contact portions 25, miniaturization of the circuit connection portion 23 (i.e., the second circuit body 20B), etc. On the lower surface of the circuit connection portion 23 of the second circuit body 20B, a metal dummy contact portion (pad) 27 is provided to be exposed to the outside at a position that does not interfere with the contact portion 25 and the wiring pattern 26, and corresponds to the dummy contact portion 27 of the first circuit body 20A. The dummy contact portion 27 is not connected (electrically connected) to the wiring pattern 26 (i.e., the bus bar 40). In the circuit connection portion 23 of the second circuit body 20B, hole portions 31 penetrating in the thickness direction (up-down direction) of the circuit connection portion 23 are respectively formed at a plurality of positions (in this example, two positions) that do not interfere with the contact portion 25, the wiring pattern 26, and the dummy contact portion 27, and correspond to the plurality of hole portions 31 of the first circuit body 20A.

[0043] The operation of connecting the circuit connecting portion 23 of the first circuit body 20A and the circuit connecting portion 23 of the second circuit body 20B to each other uses a plurality of (in this example, two) protrusions 61a (see Figure 3 ) is performed, the protrusion 61a is provided on the circuit body holding portion 61 (see Figure 3 ) at a plurality of (in this example, two) positions on the bottom wall of the first circuit body 20A and corresponding to the plurality of hole portions 31 of the first circuit body 20A and the second circuit body 20B. That is, first, in a state where the circuit connecting portion 23 of the first circuit body 20A is disposed below the circuit connecting portion 23 of the second circuit body 20B, each of the plurality of protrusions 61a is sequentially inserted from below into one of the plurality of hole portions 31 of the first circuit body 20A and a corresponding one of the plurality of hole portions 31 of the second circuit body 20B (see Figure 4 ). Thus, the first circuit body 20A and the second circuit body 20B are accommodated in the bracket 60 (circuit body holding portion 61), and a state is obtained in which the plurality of hole portions 31 of the first circuit body 20A and the plurality of hole portions 31 of the second circuit body 20B are aligned so as to overlap each other in the up-down direction.

[0044] Next, the plurality of contact portions 25 of the first circuit body 20A and the plurality of contact portions 25 of the second circuit body 20B are welded separately and independently, and the dummy contact portions 27 of the first circuit body 20A and the dummy contact portions 27 of the second circuit body 20B are welded. Generally, welding can be performed by sandwiching paste solder between the contact portions 25 arranged to face each other in the up-down direction and between the dummy contact portions 27 arranged to face each other in the up-down direction (so-called pulse heating method), and then a heater chip capable of heating the solder to a temperature at which the solder can melt is pressed against the portion to be welded, and welding is performed. Welding can be performed by a reflow soldering method using a heating furnace. The electrical connection between the circuit connection portion 23 of the first circuit body 20A and the circuit connection portion 23 of the second circuit body 20B can be performed using a conductive adhesive instead of the above-mentioned welding.

[0045] Therefore, at the portion where the circuit connection portion 23 of the first circuit body 20A and the circuit connection portion 23 of the second circuit body 20B are connected to each other, the plurality of wiring patterns 26 belonging to the first circuit body 20A and the plurality of wiring patterns 26 belonging to the second circuit body 20B are electrically connected to each other respectively and independently, and mechanically integrated. The dummy contact portion 27 of the first circuit body 20A and the dummy contact portion 27 of the second circuit body 20B are mechanically integrated with each other using solder, a conductive adhesive, etc. Therefore, the first circuit body 20A and the second circuit body 20B can be more firmly integrated.

[0046] In this way, by using the hole portion 31 of the first circuit body 20A, the hole portion 31 of the second circuit body 20B and the protrusion 61a of the bracket 60, the operation of accommodating the first circuit body 20A and the second circuit body 20B in the bracket 60 (circuit body holding portion 61) and the operation of electrically connecting the contact portion 25 (wiring pattern 26) of the first circuit body 20A and the contact portion 25 (wiring pattern 26) of the second circuit body 20B to each other can be performed together, while preventing the positional displacement of the two contact portions 25 by the protrusion 61a. When an unintentional external force is applied to the circuit body 20 (more specifically, the main line portion 21 of the first circuit body 20A and the main line portion 21 of the second circuit body 20B) after the connection, the external force is received by the protrusion 61a. Therefore, it is possible to prevent the external force from being applied to the connection portion of the contact portion 25 (wiring pattern 26) of the first circuit body 20A and the contact portion 25 (wiring pattern 26) of the second circuit body 20B. Therefore, the reliability of the electrical connection between the first circuit body 20A and the second circuit body 20B can be improved.

[0047] Next, the bracket 60 will be described. The bracket 60 is a resin molded product, and Figure 1As shown, a pair of left and right strip-shaped circuit body holding parts 61 spaced apart in the left-right direction and extending in the front-back direction are integrally included, and a plurality of connecting parts 62 connecting the pair of left and right circuit body holding parts 61 in the left-right direction at a plurality of positions in the front-back direction. A pair of left and right first circuit bodies 20A (main line part 21 and branch line part 22) are placed on the pair of left and right circuit body holding parts 61, respectively. A pair of left and right second circuit bodies 20B (main line part 21 and branch line part 22) of the circuit body 20 are placed on the pair of left and right circuit body holding parts 61, respectively.

[0048] Specifically, each of a pair of circuit body retaining portions 61 extending in the front-to-back direction includes a plurality of split bodies (not shown) arranged side by side in the front-to-back direction, and an extension and contraction portion (not shown), each of which connects the split bodies adjacent to each other in the front-to-back direction in the front-to-back direction. Each extension and contraction portion has a shape that is easy to extend and contract in the front-to-back direction due to elastic deformation. Therefore, the pair of circuit body retaining portions 61 can extend and contract along the front-to-back direction. As described above, a plurality of (two) protrusions 61a are provided on the bottom wall of the circuit body retaining portion 61 (see Figure 3 ).

[0049] For each of the pair of left and right circuit body holding portions 61, the bus bar holding portion 64 (see Figure 1 ) are integrally arranged adjacent to the outer side in the left-right direction in each of the plurality of split bodies arranged in the front-to-back direction. That is, the plurality of bus bar holding portions 64 are arranged side by side in the front-to-back direction on the outer side in the left-to-right direction of each of the pair of left and right circuit body holding portions 61. Since each bus bar holding portion 64 is arranged in a corresponding one of the split bodies, the interval in the front-to-back direction between the bus bar holding portions 64 adjacent to each other in the front-to-back direction can be changed by the action of the extension and contraction portion.

[0050] The bus bar 40 is accommodated in a corresponding one of the bus bar holding portions 64. When the bracket 60 is attached to the battery assembly 1, the bus bar 40 accommodated in the bus bar holding portion 64 is conductively connected to the corresponding positive electrode 4 and negative electrode 5 adjacent to each other in the front-rear direction on the upper surface of the battery assembly 1.

[0051] Next, the cover 70 will be described. The cover 70, which is a resin molded product, is used to cover the circuit body 20, that is, the first circuit body 20A (the main line portion 21 and the branch line portion 22) and the second circuit body 20B (the main line portion 21 and the branch line portion 22), which are placed on a pair of left and right circuit body holding portions 61 of the bracket 60 that are longer in the front-rear direction (see Figure 1 ). Therefore, if Figure 1As shown, the cover 70 has a belt-like shape formed to be long in the front-rear direction.

[0052] In the attachment completion state where the busbar module 10 has been attached to the battery assembly 1, in the battery assembly 1, a plurality of stacked single cells 2 are electrically connected in series via a plurality of busbars 40. The busbar 40 is conductively connected to an external voltage detection device via an electronic component 50 mounted on a corresponding branch portion 22, a wiring pattern 26 extending from the corresponding branch portion 22 (contact portion 24), and a connector 29 mounted on the connecting portion 28 in this order. Therefore, the voltage (potential) of the busbar 40 can be detected separately by an external voltage detection device. When an overcurrent equal to or greater than the rated current flows in the electronic component 50 for some reason, the fusing function of the electronic component 50 will come into play, so that the electrical connection between the busbar 40 and the wiring pattern 26 is cut off by the electronic component 50. Therefore, excessive current is prevented from flowing into the external voltage detection device, so that the external voltage detection device can be protected.

[0053] In the use state of the battery assembly 1 to which the bus bar module 10 has been attached, each single cell 2 included in the battery assembly 1 may expand or contract in the stacking direction (front-to-back direction) due to operational heat associated with charging and discharging, the temperature of the external environment, etc. Therefore, the battery assembly 1 may be deformed to expand and contract in the stacking direction (front-to-back direction). In addition, when a plurality of single cells 2 are stacked and arranged, due to assembly tolerances, for a manufactured battery assembly 1, the size of the battery assembly 1 in the stacking direction (front-to-back direction) may vary (manufacturing variations may occur).

[0054] In this regard, in the bus bar module 10, even when the battery assembly 1 extends and contracts in the stacking direction (front-to-back direction) due to thermal deformation of each single cell 2 and manufacturing variations of the battery assembly 1, since each of the multiple extending and contracting portions of the bracket 60 extends and contracts in the front-to-back direction, and each branch portion 22 formed by the flexible substrate is easily bent, the extension and contraction caused by the thermal deformation and manufacturing variations of the battery assembly 1 can be easily absorbed.

[0055] As described above, according to the bus bar module 10 of the present embodiment, the first circuit body 20A and the second circuit body 20B (main line) formed by the flexible substrate are integrated by electrically connecting the wiring pattern 26 of the first circuit body 20A and the wiring pattern 26 of the second circuit body 20B to each other at the overlapping portion (circuit connection portion 23) of the main line portion 21 of the first circuit body 20A and the main line portion 21 of the second circuit body 20B. In other words, the first circuit body 20A and the second circuit body 20B are electrically connected. The branch line portion 22 (branch line) extends to branch from the main line portion 21 of the first circuit body 20A and the main line portion 21 of the second circuit body 20B. Therefore, when the battery assembly 1 expands and contracts in the stacking direction (front-rear direction) due to thermal deformation of each single cell 2, each bus bar 40 can be moved in the stacking direction of the single cell 2 by bending of the branch line, etc. Similarly, by bending of the branch line, etc., the dimensional change of the battery assembly 1 in the stacking direction (front-rear direction) due to the assembly tolerance of the single cell 2 can be absorbed. In other words, the bus bar module 10 according to the present embodiment can easily cope with the expansion and contraction of the battery assembly 1 and manufacturing variations caused by the deformation of the branch line. Here, in general, even when the flexible substrate includes a large number of circuit structures, the flexible substrate can be easily and flexibly deformed with a much smaller force than the wires used in the bus bar module in the above-mentioned related art. Therefore, the assemblability of the battery assembly 1 is improved. Therefore, compared with the bus bar module in the above-mentioned related art, the bus bar module 10 according to the present embodiment is more excellent in the assemblability of the battery assembly 1 and the adaptability to the deformation and manufacturing variations of the battery assembly 1.

[0056] In addition, according to the bus bar module 10 of the present embodiment, the first circuit body 20A and the second circuit body 20B are prepared as separate bodies and then electrically connected to each other. Therefore, compared with the case where the first circuit body 20A and the second circuit body 20B are formed by a single continuous flexible substrate, the length of each of the first circuit body 20A and the second circuit body 20B in the stacking direction (front-back direction) is shortened. Therefore, when the electronic component 50 is attached (ie, installed) to the branch line portion 22, no dedicated large-scale installation equipment is required. In other words, even when the length and size of the final main line obtained by connecting the first circuit body 20A and the second circuit body 20B are not suitable for general (universal) installation equipment, after the electronic component 50 is appropriately installed on the branch line portion 22 for each of the first circuit body 20A and the second circuit body 20B, the first circuit body 20A and the second circuit body 20B can also be connected to each other. Therefore, the manufacturing cost of the bus bar module 10 can be reduced.

[0057] According to the bus bar module 10 of the present embodiment, by aligning the hole portion 31 of the first circuit body 20A and the hole portion 31 of the second circuit body 20B so as to overlap each other (for example, by inserting the protrusion 61a or the rod-shaped fixture as in the present example into the hole portion 31 of the first circuit body 20A and the hole portion 31 of the second circuit body 20B), when the two wiring patterns 26 are electrically connected to each other (for example, welded), positional shift or the like between the wiring pattern 26 of the first circuit body 20A and the wiring pattern 26 of the second circuit body 20B can be prevented. Therefore, the reliability of the electrical connection between the first circuit body 20A and the second circuit body 20B can be improved.

[0058] According to the bus bar module 10 of the present embodiment, the bracket 60 has a protrusion 61a inserted into the hole portion 31 of the first circuit body 20A and the hole portion 31 of the second circuit body 20B. Therefore, the operation of accommodating the first circuit body 20A and the second circuit body 20B in the bracket 60 and the operation of electrically connecting the wiring pattern 26 of the first circuit body 20A and the wiring pattern 26 of the second circuit body 20B to each other can be performed together, while adjusting the positions of the two wiring patterns 26 by the protrusion 61a. When an unintentional external force is applied to the main line (the first circuit body 20A and the second circuit body 20B) after the connection, the external force is received by the protrusion 61a. Therefore, it is possible to prevent the external force from being applied to the connection portion of the wiring pattern 26 of the first circuit body 20A and the wiring pattern 26 of the second circuit body 20B. Therefore, the reliability of the electrical connection between the first circuit body 20A and the second circuit body 20B can be improved.

[0059] According to the bus bar module 10 of the present embodiment, the wiring pattern 26 of the first circuit body 20A and the wiring pattern 26 of the second circuit body 20B are conductively bonded to each other by a conductive bonding material. Therefore, in addition to electrically connecting the wiring pattern 26 of the first circuit body 20A and the wiring pattern 26 of the second circuit body 20B, the first circuit body 20A and the second circuit body 20B are also mechanically integrated.

[0060] According to the bus bar module 10 of the present embodiment, in addition to joining the wiring pattern 26 of the first circuit body 20A and the wiring pattern 26 of the second circuit body 20B, the dummy contact portion 27 of the first circuit body 20A and the dummy contact portion 27 of the second circuit body 20B are joined to each other. Therefore, the first circuit body 20A and the second circuit body 20B can be more firmly integrated.

[0061] The present invention is not limited to the above-described embodiments, and various modifications can be applied within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, but can be appropriately modified, improved, etc. In addition, the materials, shapes, sizes, quantities, arrangement positions, etc. of the components in the above-described embodiments are freely selected and are not limited as long as the present invention can be implemented.

[0062] In the above embodiment, each of the first circuit body 20A and the second circuit body 20B is a so-called single-sided flexible substrate (single-sided FPC) having a single wiring layer. The circuit body 20 is configured by connecting the circuit connection portion 23 provided at the rear end portion of the first circuit body 20A and the circuit connection portion 23 provided at the front end portion of the second circuit body 20B.

[0063] On the contrary, as in Figure 5 In the first variation shown, the circuit body 20 can be configured by connecting the circuit connection portion 23 provided at the rear end portion of the first circuit body 20A and the circuit connection portion 23 provided at the front end portion of the second circuit body 20B, and connecting the circuit connection portion 23 provided at the rear end portion of the second circuit body 20B and the circuit connection portion 23 provided at the front end portion of the third circuit body 20C. Here, each of the first circuit body 20A and the third circuit body 20C can be a so-called single-sided flexible substrate (single-sided FPC) having a single wiring layer. The second circuit body 20B can be a so-called double-sided flexible substrate (double-sided FPC) having a plurality of wiring layers.

[0064] In the second circuit body 20B, a portion of the wiring pattern 26 is arranged in one wiring layer, and another portion of the wiring pattern 26 is arranged in another wiring layer. A portion and another portion of the wiring pattern 26 are connected by interlayer. The arrangement order of the wiring pattern 26 in the width direction (left-right direction) of the second circuit body 20B in one wiring layer is different from the arrangement order of the wiring pattern 26 in the width direction (left-right direction) of the second circuit body 20B in another wiring layer. Therefore, the arrangement order of the wiring pattern 26 in the first circuit body 20A and the arrangement order of the wiring pattern 26 in the third circuit body 20C can be replaced by the second circuit body 20B in any order (for example, replaced by the potential order of the bus bar 40 to which the wiring pattern 26 is connected). Therefore, compared with the case where the first circuit body 20A, the second circuit body 20B and the third circuit body 20C are completely formed by a double-sided flexible substrate, the manufacturing cost of the bus bar module 10 can be reduced.

[0065] In the above-described embodiment, in each circuit connecting portion 23 of the first circuit body 20A and the second circuit body 20B, the plurality of contact portions 25 are arranged in a spaced-apart manner in the front-rear direction (the longitudinal direction of the circuit body 20 ).

[0066] On the contrary, as in Figure 6In the second modification shown, in each circuit connection portion 23 of the first circuit body 20A and the second circuit body 20B, a plurality of contact portions 25 may be arranged in a manner spaced apart in the left-right direction (the width direction of the circuit body 20). In the second modification, the circuit body 20 is configured by engaging the contact portion 25 exposed to the lower surface of the circuit connection portion 23 of the first circuit body 20A and the contact portion 25 exposed to the lower surface of the circuit connection portion 23 of the second circuit body 20B with each other in a state where the two circuit connection portions 23 are bent so that the lower surface of the circuit connection portion 23 of the first circuit body 20A and the lower surface of the circuit connection portion 23 of the second circuit body 20B face each other in the front-rear direction.

[0067] As in Figure 7 In the third modification shown, in each circuit connection part 23 of the first circuit body 20A and the second circuit body 20B, a plurality of contact parts 25 may be arranged in a manner spaced apart in the left-right direction (width direction of the circuit body 20). In the third modification, in a state where the circuit connection part 23 of the first circuit body 20A is arranged to overlap with the lower side of the circuit connection part 23 of the second circuit body 20B, the circuit body 20 is configured by engaging the contact part 25 exposed on the upper surface of the circuit connection part 23 of the first circuit body 20A and the contact part 25 exposed on the lower surface of the circuit connection part 23 of the second circuit body 20B with each other. In the third modification, a plurality of connection points between the contact part 25 of the first circuit body 20A and the contact part 25 of the second circuit body 20B are arranged in a manner spaced apart in the left-right direction. A slit-shaped through hole 71 penetrating the circuit connection part 23 of the first circuit body 20A and the circuit connection part 23 of the second circuit body 20B in the thickness direction (up-down direction) is provided between adjacent connection points. Even when the bus bar module 10 is temporarily exposed to water or the like, a short circuit between adjacent connection points due to moisture or the like can be prevented by the through-holes 71 .

[0068] Here, in the above-mentioned embodiment of the present invention, the bus bar module (10) is a bus bar module (10) to be attached to a battery assembly (1) in which a plurality of single cells (2) are stacked, and the bus bar module (10) includes:

[0069] A first circuit body (20A) formed of a flexible substrate having a first wiring pattern (26) and including a first main line portion (21) and a first branch line portion (22), the first main line portion (21) being arranged to extend along a stacking direction of a plurality of single cells (2), and the first branch line portion (22) branching and extending from the first main line portion (21);

[0070] a second circuit body (20B) formed of a flexible substrate having a second wiring pattern (26) and including a second main line portion (21) and a second branch line portion (22), the second main line portion (21) being arranged to extend along the stacking direction, and the second branch line portion (22) branching and extending from the second main line portion (21);

[0071] A bus bar (40) configured to be connected to adjacent electrodes (4, 5) between the plurality of cells (2);

[0072] electronic components (50), each of which is attached to the first branch line portion (22) and the second branch line portion (22) so that each electronic component connects the first wiring pattern (26) and the second wiring pattern (26) to the corresponding bus bar (40); and

[0073] A bracket (60) is extendable and retractable along the stacking direction and holds the first circuit body (20A), the second circuit body (20B) and the bus bar (40), wherein

[0074] The first wiring pattern (26) and the second wiring pattern (26) are electrically connected to each other at an overlapping portion (23) of the first main line portion (21) and the second main line portion (21).

[0075] According to the bus bar module having the above configuration, the first circuit body and the second circuit body (hereinafter also referred to as "main line") formed by the flexible substrate are integrated by electrically connecting the first wiring pattern and the second wiring pattern at the overlapping portion of the first main line portion of the first circuit body and the second main line portion of the second circuit body. In other words, the first circuit body and the second circuit body are electrically connected to each other. The first branch line portion and the second branch line portion (hereinafter also referred to as "branch") extend to branch from the first main line portion and the second main line portion, respectively. Therefore, when the battery assembly expands and contracts in the stacking direction due to the thermal deformation of each single cell, each bus bar can be moved in the stacking direction of the single cell by bending of the branch line, etc. Similarly, by bending of the branch line, etc., the dimensional change of the battery assembly in the stacking direction caused by the assembly tolerance of the single cell can be absorbed. In other words, the bus bar module having the present configuration can easily cope with the extension and contraction of the battery assembly and the manufacturing variation caused by the deformation of the branch line. Here, in general, even when the flexible substrate includes a large number of circuit structures, the flexible substrate can be easily and flexibly deformed with a much smaller force than the wires used in the bus bar module in the above-mentioned related art. Therefore, the assemblability of the battery assembly is improved. Therefore, compared with the bus bar module in the above-mentioned related art, the bus bar module having the present configuration is more excellent in assemblability of the battery assembly and adaptability to deformation and manufacturing variations of the battery assembly.

[0076] According to the bus bar module having the above configuration, the first circuit body and the second circuit body are prepared as separate bodies and then electrically connected to each other. Therefore, compared with the case where the first circuit body and the second circuit body are formed by a single continuous flexible substrate, the length of each of the first circuit body and the second circuit body in the stacking direction is shortened. Therefore, when the electronic component is attached to (i.e., installed to) the first branch line portion and the second branch line portion, no dedicated large-scale installation equipment is required. In other words, even when the length and size of the final main line obtained by connecting the first circuit body and the second circuit body are not suitable for general (universal) installation equipment, the first circuit body and the second circuit body can also be connected to each other after the electronic component is appropriately installed on the branch circuit body using general (universal) installation equipment for each of the first circuit body and the second circuit body. Therefore, the manufacturing cost of the bus bar module can be reduced.

[0077] The first circuit body (20A) may have a first hole portion (31) penetrating the first circuit body (20A) in the thickness direction,

[0078] The second circuit body (20B) may have a second hole portion (31) penetrating the second circuit body (20B) in the thickness direction, and

[0079] The first wiring pattern (26) and the second wiring pattern (26) may be electrically connected to each other in a state where the first hole portion (31) and the second hole portion (31) are aligned to overlap each other.

[0080] According to the bus bar module having the above configuration, by aligning the first hole portion of the first circuit body and the second hole portion of the second circuit body so as to overlap each other (for example, by inserting a rod-shaped fixture into the first hole portion and the second hole portion), when the two wiring patterns are electrically connected (for example, by welding), positional shift between the first wiring pattern and the second wiring pattern can be prevented, etc. Therefore, the reliability of the electrical connection between the first circuit body and the second circuit body can be improved.

[0081] The first circuit body (20A) may have a single wiring layer, and may be configured such that the first wiring pattern (26) is arranged in the single wiring layer,

[0082] The second circuit body (20B) may have a plurality of wiring layers, the second wiring pattern (26) may include a plurality of second wiring patterns (26), and the second circuit body (20B) may be configured such that a portion of the second wiring pattern (26) is arranged in one wiring layer, and another portion of the second wiring pattern (26) is arranged in another wiring layer,

[0083] A part and another part of the second wiring pattern (26) may be connected between layers, and

[0084] The arrangement order of the second wiring patterns (26) in one wiring layer in the width direction of the second circuit body (20B) may be different from the arrangement order of the second wiring patterns (26) in another wiring layer in the width direction of the second circuit body (20B).

[0085] According to the bus bar module having the above configuration, the first circuit body is a circuit body having a single wiring layer (e.g., a single-sided flexible substrate), and the second circuit body is a circuit body having multiple wiring layers (e.g., a double-sided flexible substrate). In the second circuit body, the arrangement order of the second wiring pattern in one wiring layer in the width direction is different from the arrangement order of the second wiring pattern in another wiring layer in the width direction. Therefore, for example, the arrangement order of the first wiring pattern in the first circuit body can be replaced by any order by the second circuit body (e.g., replaced by the potential order of the busbars to which the individual wirings including the first wiring pattern are connected). Therefore, compared with the case where the first circuit body and the second circuit body are completely formed by a circuit body having multiple wiring layers, the manufacturing cost of the bus bar module can be reduced.

[0086] The bracket (60) may include a protrusion (61a) inserted into the first hole portion (31) and the second hole portion (31).

[0087] According to the bus bar module having the above-mentioned configuration, the bracket has a protrusion inserted into the first hole portion of the first circuit body and the second hole portion of the second circuit body. Therefore, the operation of accommodating the first circuit body and the second circuit body in the bracket and the operation of electrically connecting the wiring pattern of the first circuit body and the wiring pattern of the second circuit body to each other can be performed together, while adjusting the positions of the two wiring patterns by the protrusion. When an unintentional external force is applied to the main line (the first circuit body and the second circuit body) after the connection, the external force is received by the protrusion. Therefore, it is possible to prevent the external force from being applied to the connection portion of the wiring pattern of the first circuit body and the wiring pattern of the second circuit body. Therefore, the reliability of the electrical connection between the first circuit body and the second circuit body can be improved.

[0088] The first wiring pattern (26) and the second wiring pattern (26) can be conductively bonded by a conductive bonding material.

[0089] According to the busbar module having the above configuration, the first wiring pattern and the second wiring pattern are conductively bonded by a conductive bonding material. Therefore, in addition to electrically connecting the wiring pattern of the first circuit body and the wiring pattern of the second circuit body, the first circuit body and the second circuit body are also mechanically integrated. Examples of the conductive bonding material include solder and a conductive adhesive.

[0090] The first circuit body (20A) may have a first dummy wiring pattern (27) not connected to the bus bar (40),

[0091] The second circuit body (20B) may have a second dummy wiring pattern (27) not connected to the bus bar (40), and

[0092] The first dummy wiring pattern (27) and the second dummy wiring pattern (27) may be joined.

[0093] According to the bus bar module having the above configuration, in addition to joining the first wiring pattern and the second wiring pattern, the first dummy wiring pattern of the first circuit body and the second dummy wiring pattern of the second circuit body are joined. Therefore, the first circuit body and the second circuit body can be more firmly integrated.

[0094] This application is based on the Japanese patent application filed on November 30, 2022 (Japanese Patent Application No. 2022-192291), the contents of which are incorporated herein by reference.

[0095] Industrial Applicability

[0096] The bus bar module according to the present invention is excellent in the assemblability of the battery assembly and the adaptability to the deformation and manufacturing variation of the battery assembly. The present invention having such an effect can be used, for example, for assembling into a long battery assembly (for example, a battery module in which a plurality of single cells are stacked and arranged) which is used as a driving power source mounted on an electric vehicle.

[0097] Reference numerals list

[0098] 1: Battery components

[0099] 2: Single battery

[0100] 4: Positive electrode (electrode)

[0101] 5: Negative electrode

[0102] 10: Busbar module

[0103] 20A: First circuit body

[0104] 20B: Second circuit body

[0105] 21: Main line part (first main line part, second main line part)

[0106] 22: Branch line part (first branch line part, second branch line part)

[0107] 23: Circuit connection part (overlapping part)

[0108] 26: Wiring pattern (first wiring pattern, second wiring pattern)

[0109] 27: Dummy connector (first dummy wiring pattern, second dummy wiring pattern)

[0110] 31: Hole portion (first hole portion, second hole portion)

[0111] 40: Busbar

[0112] 50: Electronic components

[0113] 60: Bracket

[0114] 61a: protrusion.

Claims

1. A bus bar module to be attached to a battery assembly in which a plurality of single cells are stacked, the bus bar module comprising: a first circuit body formed of a flexible substrate having a first wiring pattern and including a first main line portion and a first branch line portion, the first main line portion being arranged to extend along a stacking direction of the plurality of single cells and the first branch line portion extending to branch from the first main line portion; a second circuit body formed of a flexible substrate having a second wiring pattern and including a second main line portion arranged to extend along the stacking direction and a second branch line portion extending to branch from the second main line portion; a bus bar configured to be connected to adjacent electrodes between the plurality of battery cells; electronic components each attached to the first branch line portion and the second branch line portion so that each electronic component connects the first wiring pattern and the second wiring pattern to a corresponding bus bar; and a bracket capable of extending and contracting along the stacking direction and holding the first circuit body, the second circuit body and the bus bar, wherein The first wiring pattern and the second wiring pattern are electrically connected to each other at an overlapping portion of the first main line portion and the second main line portion.

2. The bus bar module according to claim 1, wherein The first circuit body has a first hole portion penetrating the first circuit body in a thickness direction, The second circuit body has a second hole portion penetrating the second circuit body in the thickness direction, and The first wiring pattern and the second wiring pattern are electrically connected to each other in a state where the first hole portion and the second hole portion are aligned to overlap each other.

3. The bus bar module according to claim 1, wherein the first circuit body has a single wiring layer, and is configured such that the first wiring pattern is arranged in the single wiring layer, The second circuit body has a plurality of wiring layers, the second wiring pattern includes a plurality of second wiring patterns, and the second circuit body is configured so that a portion of the second wiring pattern is arranged in one wiring layer and another portion of the second wiring pattern is arranged in another wiring layer, The part and the other part of the second wiring pattern are connected by interlayers, and An arrangement order of the second wiring patterns in the one wiring layer in the width direction of the second circuit body is different from an arrangement order of the second wiring patterns in the other wiring layer in the width direction of the second circuit body.

4. The bus bar module according to claim 2, wherein The bracket includes a protrusion inserted into the first hole portion and the second hole portion.

5. The bus bar module according to claim 1, wherein The first wiring pattern and the second wiring pattern are conductively bonded by a conductive bonding material.

6. The bus bar module according to claim 5, wherein The first circuit body has a first dummy wiring pattern not connected to the bus bar, The second circuit body has a second dummy wiring pattern not connected to the bus bar, and The first dummy wiring pattern and the second dummy wiring pattern are joined.

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