Bus bar module

Abstract

A bus bar module (10) includes a first circuit body (20A), a second circuit body (20B), and an electronic component (50). 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). In the plurality of first and second contact portions (25), the first and second wiring portions extend from one of the first and second contact portions (25) to one side in an intersecting direction intersecting the stacking direction, and the first and second wiring portions extend from the other first and second contact portions (25) to the other side in the intersecting direction.

Description

Technical Field

[0001] The present disclosure relates to a bus bar module. Background Art

[0002] In the related art, for example, a bus bar module is used by being assembled into 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, or the like (eg, see Patent Document 1).

[0003] The bus bar module described in Patent Document 1 includes a plurality of bus bars stacked and connecting positive and negative electrodes between adjacent battery cells, and a voltage detection line connected to the plurality of bus bars and monitoring the battery cells. The voltage detection line is configured to bundle together a plurality of wires having 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] Typically, the battery cells forming 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, due to assembly tolerances when stacking and arranging a plurality of battery cells, the dimensions of the battery assembly in the stacking direction will typically differ for each manufactured battery assembly (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.

[0008] However, in the above-mentioned bus bar module of the related art, for example, when the number of stacked battery cells increases to increase the capacity of the battery assembly, the number of wires forming the voltage detection line also increases. Therefore, when a plurality of wires are bundled together to form the voltage detection line, the stiffness of the voltage detection line as a whole (and thus the stiffness of the bus bar module) increases, and this may make it difficult to improve the operability (assembly ease) of assembling the bus bar module to the battery assembly. For the same reason, the bus bar module may also become difficult to fully expand and contract to cope with deformation and manufacturing variations of the battery assembly.

[0009] An object of the present invention is to provide a bus bar module that is easily assembled to a battery assembly and has good adaptability to deformation and manufacturing variations of the battery assembly.

[0010] Solution to the problem

[0011] 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:

[0012] a first circuit body formed of a flexible substrate having a first wiring pattern and including a first main line portion extending along a stacking direction of the plurality of single cells and a first branch line portion extending so as to branch from the first main line portion;

[0013] a second circuit body formed of a flexible substrate having a second wiring pattern and including a second main line portion extending in the stacking direction and a second branch line portion extending so as to branch from the second main line portion;

[0014] bus bars, each bus bar being connected to electrodes of a plurality of single cells;

[0015] an electronic component attached to the first branch line portion and the second branch line portion such that the first wiring pattern and the second wiring pattern are connected to corresponding bus bars; and

[0016] A bracket is extendable and retractable along the stacking direction and is configured to hold the first circuit body, the second circuit body and the bus bar, wherein

[0017] The first wiring pattern has a plurality of first contact portions arranged in the stacking direction and a first wiring portion extending from each of the plurality of first contact portions, and is configured such that the first wiring portion extends from one of the first contact portions to one side in a crossing direction crossing the stacking direction, and the first wiring portion extends from the other first contact portion to the other side in the crossing direction,

[0018] The second wiring pattern has a plurality of second contact portions arranged in the stacking direction and a second wiring portion extending from each of the plurality of second contact portions, and is configured such that the second wiring portion extends from one of the second contact portions to one side in the crossing direction, and the second wiring portion extends from the other second contact portion to the other side in the crossing direction, and

[0019] The plurality of first contact portions and the plurality of second contact portions are electrically connected to each other at overlapping portions of the first main line portion and the second main line portion, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a perspective view of a bus bar module according to the present embodiment.

[0021] Figure 2 It shows Figure 1A perspective view of a battery assembly into which a bus bar module is to be assembled is shown.

[0022] Figure 3 It is shown that when the Figure 1 The illustrated circuit body is a perspective view of a process in which a first circuit body and a second circuit body are connected and accommodated in a bracket.

[0023] Figure 4 It shows the formation Figure 1 A perspective view showing a state in which a first circuit body and a second circuit body of a circuit body are connected and accommodated in a bracket.

[0024] Figure 5 yes Figure 4 A top view of a portion where connecting portions of a first circuit body and a second circuit body are connected to each other (the bracket is not shown). DETAILED DESCRIPTION

[0025] The bus bar module 10 according to an embodiment of the present invention will be described below with reference to the accompanying drawings. The bus bar module 10 according to this embodiment is assembled to the long battery assembly 1 (see FIG. Figure 2 , in which a battery module in which a plurality of single cells are stacked and arranged) is used, and the battery assembly 1 is used as a driving power source mounted on an electric vehicle.

[0026] In the following, for the convenience of description, the definitions of “front”, “rear”, “left”, “right”, “upper” and “lower” are 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 forming the battery assembly 1 (see Figure 1 and 2 Note that 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.

[0027] 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 attached is described. Figure 2 As shown, the battery assembly 1 is formed by stacking a plurality of rectangular flat-plate-shaped cells 2 extending in the up-down direction and the left-right direction in the front-to-back 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 an upper surface 6 of the battery body 3.

[0028] In the battery assembly 1, a plurality of single cells 2 are stacked by reversing the positions of the positive electrodes 4 and the negative electrodes 5 of the single cells 2 adjacent to each other in the front-to-back direction in the left-to-right direction, so that the positive electrodes 4 and the negative electrodes 5 are alternately arranged at the left and right ends of the upper surface of the battery assembly 1 in the front-to-back direction.

[0029] The bus bar module 10 will be described below. Figure 1 , 3 As shown in FIG. 4 , the busbar module 10 includes: a long circuit body 20 extending in the front-to-back direction (see FIG. Figure 1 and 3 ); respectively connected to the circuit body 20 of the plurality of branch line portions 22 (see Figure 3 ) of a plurality of bus bars 40 (see Figure 1 ); a plurality of electronic components 50 are mounted on a plurality of branch line portions 22 (see Figure 3 ); holding the circuit body 20 and the bus bar 40 of the bracket 60 (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.

[0030] The circuit body 20 is made of a flexible substrate (FPC) that is easy to bend. 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. One of the pair of left and right first circuit bodies 20A and the pair of left and right second circuit bodies 20B is connected to the left and right first circuit bodies 20A by a connecting portion 28 (see FIG. Figure 1 ) is connected in the left-right direction. A 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.

[0031] 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 in the front-rear direction of the main line portion 21 (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-rear, left-right, and up-and-down directions is improved. The contact portion 24 made of metal is provided on the upper surface of the end portion of the branch line portion 22 so as to be exposed to the outside (see Figure 3 ).

[0032] 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, the main line portion 21 of the first circuit body 20A and the main line portion 21 of the second circuit body 20B are continuous with each other and extend in a row in the front-rear direction to form the circuit body 20. 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.

[0033] Except for the exposed portion of the contact portion 24 provided on the branch line portion 22 (see Figure 3 ) and a portion in which the contact portion 25 provided on the circuit connecting portion 23 described later is exposed (see Figure 3 ), the entire surface of the first circuit body 20A and the second circuit body 20B are made of a resin layer. Each of the first circuit body 20A and the second circuit body 20B includes a plurality of wiring patterns 26 therein (see Figure 3 ). Each 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.

[0034] 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 independently connected to each other (see Figure 3 , details to be given later).

[0035] 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, starting from the contact portion 24 of the corresponding branch line portion 22, sequentially through the inside of 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 individually conductively connected to the external voltage detection device via the connector 29 mounted on the connecting portion 28.

[0036] The 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 FIG. Figure 3 The connection terminal 41 may be a bus bar 40 (see Figure 1 ), which is a part of the bus bar 40 made of metal and having a substantially rectangular flat plate shape, or may be a member separated from the bus bar 40 and 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 end portion of the branch portion 22 by welding or the like so as to connect the contact portion 24 of the branch portion 22 with the connection terminal 41. Therefore, at each branch 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.

[0037] 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 both the first circuit body 20A and the second circuit body 20B are in an independent state), such mounting of the electronic component 50 on the branch line portion 22 is performed separately for 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 each branch line portion 22, and the manufacturing cost of the bus bar module 10 can be reduced.

[0038] Hereinafter, the detailed structure of the circuit connection portion 23 of each of the first circuit body 20A and the circuit connection portion 23 of the second circuit body 20B and the connection procedure between the circuit connection portions 23 will be described. Figure 3 and Figure 5 As shown, on the upper surface of the circuit connection part 23 of the first circuit body 20A, a plurality of (in this example, six) contact parts (pads) 25 made of metal are arranged in a spaced manner in the front-to-back direction and exposed to the outside. A wiring pattern 26 extends separately from each contact part 25. More specifically, for each of the three contact parts 25 on the front side (the base end 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 end 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.

[0039] In this way, by arranging the extensions of the plurality of wiring patterns 26 extending from the plurality of contact portions 25 in a manner distributed 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), and the like. On the upper surface of the circuit connection portion 23 of the first circuit body 20A, a dummy contact portion (pad) 27 made of metal 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. 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-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.

[0040] In the circuit connecting portion 23 of the first circuit body 20A, slit-like through holes (hereinafter referred to as “isolation hole portions 32”) penetrating in the thickness direction (up-down direction) of the circuit connecting portion 23 are respectively formed to extend in the left-right direction at positions (five positions) each of which is located between the contact portions 25 adjacent to each other in the front-to-back direction among the plurality of (six) contact portions 25 arranged in the front-to-back direction (see FIG. Figure 3 and Figure 5 ). Therefore, the problem that the adjacent contact portions 25 are connected (short-circuited) due to moisture when the bus bar module 10 is exposed to water or the like can be prevented from occurring. In addition, two of the five isolation hole portions 32 are connected to the two hole portions 31, respectively. Therefore, the diameter of the isolation hole portion 32 is enlarged, and the above-mentioned short-circuit prevention effect can be further improved.

[0041] On the lower surface of the circuit connection portion 23 of the second circuit body 20B, a plurality of (six in this example) contact portions (pads) 25 made of metal are arranged in a spaced manner in the front-rear direction and exposed to the outside, corresponding to the plurality of contact portions 25 of the first circuit body 20A. A wiring pattern 26 extends individually from each contact portion 25. More specifically, for each of the three contact portions 25 on the front side (the end 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 (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 base end 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 (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 in 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 dummy contact portion (pad) 27 made of metal 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, corresponding 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). Corresponding to the multiple hole portions 31 of the first circuit body 20A, in the circuit connecting portion 23 of the second circuit body 20B, the hole portions 31 penetrating in the thickness direction (up and down direction) of the circuit connecting portion 23 are respectively formed at multiple 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.

[0043] In the circuit connecting portion 23 of the second circuit body 20B, similarly to the isolation hole portion 32 of the first circuit body 20A, slit-shaped isolation hole portions 32 penetrating in the thickness direction (up-down direction) of the circuit connecting portion 23 are respectively formed to extend in the left-right direction at positions (five positions) each of which is located between the contact portions 25 adjacent to each other in the front-to-back direction among the plurality of (six) contact portions 25 arranged in the front-to-back direction (see Figure 3 and Figure 5). Therefore, the problem that the adjacent contact portions 25 are connected (short-circuited) due to moisture when the bus bar module 10 is exposed to water or the like can be prevented from occurring. In addition, two of the five isolation hole portions 32 are connected to the two hole portions 31, respectively. Therefore, the diameter of the isolation hole portion 32 is enlarged, and the above-mentioned short-circuit prevention effect can be further improved.

[0044] 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 plurality of protrusions 61a (see Figure 3 ) is provided in the circuit body holding portion 61 described later on the bracket 60 (see Figure 3 ) at multiple (in this example, two) positions on the bottom wall of the first circuit body 20A, corresponding to the multiple 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 arranged below the circuit connecting portion 23 of the second circuit body 20B, the multiple protrusions 61a are sequentially inserted from below into the multiple hole portions 31 of the first circuit body 20A and the multiple 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.

[0045] 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 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 together. Generally, welding can be performed by a method (so-called pulse heating method), which sandwiches paste solder between the contact portions 25 arranged facing each other in the up-down direction and between the dummy contact portions 27 arranged facing each other in the up-down direction, and then presses a heater chip against the portion to be welded, and performs welding, and the heater chip can heat the solder to a temperature at which the solder can melt. 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.

[0046] Therefore, at the position where the circuit connection part 23 of the first circuit body 20A and the circuit connection part 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 respectively and independently electrically connected to each other and mechanically integrated. In addition, the dummy contact part 27 of the first circuit body 20A and the dummy contact part 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.

[0047] 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 position of the contact portion 25 from being shifted 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.

[0048] Next, the bracket 60 will be described. The bracket 60 is a resin molded product, and Figure 1 As shown, it integrally includes 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, 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+branch line part 22) and a pair of left and right second circuit bodies 20B (main line part 21+branch line part 22) of the circuit body 20 are placed on the pair of left and right circuit body holding parts 61, respectively.

[0049] Specifically, each of a pair of circuit body holding 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) connecting 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 holding portions 61 can extend and contract in the front-to-back direction. As described above, a plurality of (two) protrusions 61a are provided on the bottom wall of the circuit body holding portion 61 (see Figure 3 ).

[0050] For each of the pair of left and right circuit body holding portions 61, the bus bar holding portion 64 (see Figure 1 ) is integrally provided adjacent to the outer side in the left-right direction of 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 provided in the corresponding split body, 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.

[0051] Each bus bar holding portion 64 accommodates a corresponding bus bar 40. When the bracket 60 is attached to the battery assembly 1, the bus bars 40 accommodated in the bus bar holding portions 64 are conductively connected to the corresponding positive electrodes 4 and negative electrodes 5 adjacent to each other in the front-rear direction on the upper surface of the battery assembly 1.

[0052] 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 (main line portion 21+branch line portion 22) and the second circuit body 20B (main line portion 21+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 1 As shown, the cover 70 has a belt-like shape formed to be long in the front-rear direction.

[0053] In the state where the busbar module 10 is attached to the battery assembly 1, in the battery assembly 1, a plurality of stacked single cells 2 are electrically connected in series through a plurality of busbars 40. In addition, each busbar 40 is conductively connected to an external voltage detection device in sequence 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 a connecting portion 28. 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 causes the electronic component 50 to cut off the electrical connection between the busbar 40 and the wiring pattern 26. Therefore, an overcurrent is prevented from flowing into the voltage detection device, so that the voltage detection device can be protected.

[0054] In the use state of the battery assembly 1 to which the bus bar module 10 is attached, each single cell 2 forming 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, due to assembly tolerances when stacking and arranging a plurality of single cells 2, for each manufactured battery assembly 1, the size of the battery assembly 1 in the stacking direction (front-to-back direction) generally varies (manufacturing variations may occur).

[0055] In this regard, in the bus bar module 10, even if 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.

[0056] 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. In addition, the branch line portion 22 (branch line) extends to branch from the main line portion 21 of the first circuit body 20A and from 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 the branch line, etc. Similarly, by bending the branch line, etc., the size 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 by deforming 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 ease of assembly into the battery assembly 1 is improved. Therefore, the bus bar module 10 according to the present embodiment can be easily assembled to the battery assembly 1, and has better adaptability to the deformation and manufacturing variations of the battery assembly 1 than the bus bar module in the above-mentioned related art.

[0057] Furthermore, in the bus bar module 10 according to the present embodiment, for the circuit connection portion 23 of the first circuit body 20A, among the plurality of contact portions 25 arranged in the stacking direction (front-rear direction) of the plurality of cells 2, the extension portion of the wiring pattern 26 extends from one contact portion 25 to one side in the crossing direction (left-right direction), and the extension portion of the wiring pattern 26 extends from another contact portion 25 to the other side in the crossing direction (left-right direction). Therefore, by arranging the extension portions of the plurality of wiring patterns 26 extending from the plurality of contact portions 25 in a distributed manner in the crossing direction (left-right direction), it is possible to contribute to an improvement in the degree of freedom of pattern design of the extension portions of the wiring patterns 26 extending from the contact portions 25, miniaturization of the first circuit body 20A, and the like. The same applies to the circuit connection portion 23 of the second circuit body 20B.

[0058] In addition, 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 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 (i.e., installed) to each branch line portion 22, no dedicated large-scale installation equipment is required. In other words, even when the length or size of the final main line obtained by connecting the first circuit body 20A and the second circuit body 20B is 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 busbar module 10 can be reduced.

[0059] In addition, according to the bus bar module 10 of the present embodiment, the slit-shaped isolation hole portion 32 is provided between adjacent connection positions of the contact portions 25 of the first circuit body 20A and the second circuit body 20B. Therefore, it is possible to prevent the occurrence of a problem in which adjacent connection positions are conducted (short-circuited) due to moisture when the bus bar module 10 is exposed to water or the like.

[0060] In addition, 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 that they overlap each other (for example, by inserting the protrusion 61a or the rod-shaped clamp in this 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), the positional shift 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, etc. Therefore, the reliability of the electrical connection between the first circuit body 20A and the second circuit body 20B can be improved. In addition, since the hole portion 31 and the isolation hole portion 32 are connected to each other, the diameter of the isolation hole portion 32 is increased, and the above-mentioned short circuit prevention effect can be further improved.

[0061] In addition, according to the bus bar module 10 of the present embodiment, the bracket 60 has a protrusion 61a, which is 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.

[0062] In addition, 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.

[0063] Furthermore, 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.

[0064] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. can be made appropriately. 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 achieved.

[0065] According to the above embodiment of the present invention, the busbar module (10) is a busbar module (10) to be attached to a battery assembly (1), in which a plurality of single cells (2) are stacked, and the busbar module comprises:

[0066] 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 extending along a stacking direction of a plurality of single cells (2), and the first branch line portion extending to branch from the first main line portion (21);

[0067] 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 extending along the stacking direction and the second branch line portion extending to branch from the second main line portion (21);

[0068] Bus bars (40), each bus bar being connected to electrodes (4, 5) of a plurality of single cells (2);

[0069] an electronic component (50) attached to the first branch line portion (22) and the second branch line portion (22) such that the first wiring pattern (26) and the second wiring pattern (26) are connected to the corresponding bus bars (40); and

[0070] A bracket (60) is capable of extending and contracting along a stacking direction and is configured to hold a first circuit body (20A), a second circuit body (20B) and a bus bar (40), wherein

[0071] The first wiring pattern (26) has a plurality of first contact portions (25) arranged in the stacking direction and a first wiring portion extending from each of the plurality of first contact portions (25), and is configured such that the first wiring portion extends from one of the first contact portions (25) to one side in a crossing direction crossing the stacking direction, and the first wiring portion extends from another first contact portion (25) to the other side in the crossing direction,

[0072] The second wiring pattern (26) has a plurality of second contact portions (25) arranged in the stacking direction and a second wiring portion extending from each of the plurality of second contact portions (25), and is configured such that the second wiring portion extends from one of the second contact portions (25) to one side in the crossing direction, and the second wiring portion extends from the other second contact portion (25) to the other side in the crossing direction, and

[0073] A plurality of first contact portions (25) and a plurality of second contact portions (25) are electrically connected to each other at overlapping portions (23) of the first main line portion (21) and the second main line portion (21), respectively.

[0074] 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 contact portion of the first wiring pattern and the second contact portion of 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 line") 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 the branch line, etc. Similarly, by bending the branch line, etc., the size change of the battery assembly in the stacking direction caused by the assembly tolerance of the single cell can be absorbed. In other words, by deforming the branch line, the bus bar module having the present configuration can easily cope with the extension and contraction of the battery assembly and manufacturing changes. 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 ease of assembly into 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 can be easily assembled into the battery assembly and has better adaptability to deformation and manufacturing variations of the battery assembly.

[0075] According to the busbar module having the above configuration, among the multiple first contact portions arranged along the stacking direction of the multiple single cells, the first wiring portion extends from one first contact portion to one side in the cross direction, and the first wiring portion extends from another first contact portion to the other side in the cross direction. Therefore, by arranging the multiple first wiring portions extending from the multiple first contact portions in a distributed manner in the cross direction, it can help to improve the freedom of pattern design of the first wiring portion, miniaturization of the first circuit body, etc. The same applies to the second wiring pattern of the second circuit body. In addition, 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., mounted to) the first branch line portion and the second branch line portion, no dedicated large-scale mounting equipment is required. In other words, even when the length or size of the final main line obtained by connecting the first circuit body and the second circuit body is not suitable for general (universal) mounting equipment, the first circuit body and the second circuit body can be connected to each other after the electronic components are appropriately mounted on the branch circuit body using general (universal) mounting 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.

[0076] Furthermore, the first circuit body (20A) may have a slit-shaped isolation hole portion (32) penetrating the overlapping portion (23) in the thickness direction between adjacent connection positions among a plurality of connection positions with the first contact portion (25), and

[0077] The second circuit body (20B) may have a slit-shaped isolation hole portion (32) penetrating the overlapping portion (23) in the thickness direction between adjacent connection positions among a plurality of connection positions with the second contact portion (25).

[0078] According to the bus bar module having the above configuration, the slit-shaped isolation hole portion is provided between adjacent connection positions of the first contact portion and the second contact portion. Therefore, the problem of conduction (short circuit) of adjacent connection positions due to moisture when the bus bar module is exposed to water or the like can be prevented from occurring.

[0079] Furthermore, the first circuit body (20A) may have a first hole portion (31) penetrating the first circuit body (20A) in the thickness direction,

[0080] The second circuit body (20B) may have a second hole portion (31) penetrating the second circuit body (20B) in the thickness direction,

[0081] The first contact portion (25) and the second contact portion (25) can be electrically connected in a state where the first hole portion (31) and the second hole portion (31) are aligned to overlap each other, and

[0082] The first hole portion (31) may communicate with the isolation hole portion (32), and the second hole portion (31) may communicate with the isolation hole portion (32).

[0083] 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 that they overlap each other (for example, by inserting a rod-shaped jig into the first hole portion and the second hole portion), when the two wiring patterns are electrically connected (for example, welded), positional shift between the first wiring pattern and the second wiring pattern can be prevented, etc. Because at least one of the first hole portion and the second hole portion is connected to the isolation hole portion, the diameter of the isolation hole portion is increased, and the above short circuit prevention effect can be further improved. The connected hole portion can be used for alignment.

[0084] Furthermore, the bracket (60) may have a protrusion (61a) for insertion into the first hole portion (31) and the second hole portion (31).

[0085] According to the bus bar module having the above configuration, the bracket has a protrusion, which is used to insert 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. In addition, 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.

[0086] This application is based on the Japanese patent application filed on November 30, 2022 (Japanese patent application number 2022-192293), the contents of which are incorporated herein by reference.

[0087] Industrial Applicability

[0088] The bus bar module according to the present invention can be easily assembled to a battery assembly and has good adaptability to deformation and manufacturing deviation of the battery assembly. The present invention having such an effect can be used, for example, for assembly to a long battery assembly (e.g., a battery module in which a plurality of single cells are stacked and arranged) used as a driving power source mounted on an electric vehicle.

[0089] Reference numerals list

[0090] 1: Battery components

[0091] 2: Single battery

[0092] 4: Positive electrode

[0093] 5: Negative electrode

[0094] 10: Busbar module

[0095] 20A: First circuit body

[0096] 20B: Second circuit body

[0097] 21: Main line part (first main line part, second main line part)

[0098] 22: Branch line part (first branch line part, second branch line part)

[0099] 23: Circuit connection part (overlapping part)

[0100] 25: Contact part (first contact part, second contact part)

[0101] 26: Wiring pattern (first wiring pattern, second wiring pattern)

[0102] 31: Hole portion (first hole portion, second hole portion)

[0103] 32: Isolation hole part

[0104] 40: Busbar

[0105] 50: Electronic components

[0106] 60: Bracket

[0107] 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 extending along a stacking direction of the plurality of single cells and a 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 extending along the stacking direction and a second branch line portion extending to branch from the second main line portion; bus bars, each bus bar being connected to electrodes of the plurality of single cells; an electronic component attached to the first branch line portion and the second branch line portion such that the first wiring pattern and the second wiring pattern are connected to corresponding bus bars; and a bracket capable of extending and contracting along the stacking direction and configured to hold the first circuit body, the second circuit body, and the bus bar, wherein the first wiring pattern has a plurality of first contact portions arranged in the stacking direction and a first wiring portion extending from each of the plurality of first contact portions, and is configured such that the first wiring portion extends from one of the first contact portions to one side in a crossing direction crossing the stacking direction, and the first wiring portion extends from the other first contact portion to the other side in the crossing direction, wherein the second wiring pattern has a plurality of second contact portions arranged in the stacking direction and a second wiring portion extending from each of the plurality of second contact portions, and is configured such that the second wiring portion extends from one of the second contact portions to one side in the crossing direction, and the second wiring portion extends from the other second contact portion to the other side in the crossing direction, and The plurality of first contact portions and the plurality of second contact portions are electrically connected to each other at overlapping portions of the first main line portion and the second main line portion, respectively.

2. The bus bar module according to claim 1, in, The first circuit body has a slit-shaped isolation hole portion that penetrates the overlap portion in the thickness direction between adjacent connection positions among a plurality of connection positions with the first contact portion, and The second circuit body has a slit-shaped isolation hole portion that penetrates the overlapped portion in the thickness direction between adjacent connection locations among a plurality of connection locations with the second contact portion.

3. The bus bar module according to claim 2, in, The first circuit body has a first hole portion penetrating the first circuit body in the thickness direction, wherein the second circuit body has a second hole portion penetrating the second circuit body in the thickness direction, wherein the first contact portion and the second contact portion are electrically connected in a state where the first hole portion and the second hole portion are aligned to overlap each other, and wherein the first hole portion is in communication with the isolation hole portion, and the second hole portion is in communication with the isolation hole portion.

4. The bus bar module according to claim 3, in, The bracket has protrusions to be inserted into the first hole portion and the second hole portion.

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