Bus bar module

Abstract

A bus bar module (10) to be attached to a battery assembly (1) includes: a first circuit body (20A) having a first wiring pattern (26); a second circuit body (20B) having a second wiring pattern (26); and an electronic component (50) attached to the first and second leg portions (22) to connect the first and second wiring patterns (26) and the bus bar (40). The first and second wiring patterns (26) are electrically connected at an overlapping portion (23) of the first and second main line portions (21). The bus bar module (10) further includes a waterproof portion sealing the overlapping portion (23) in a watertight manner.

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] Technical issues

[0008] 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.

[0009] 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.

[0010] 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.

[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 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;

[0014] 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;

[0015] bus bars, each bus bar being connected to electrodes of a plurality of single cells;

[0016] 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

[0017] 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

[0018] The first wiring pattern includes a plurality of first contact portions arranged in the stacking direction,

[0019] the second wiring pattern includes a plurality of second contact portions arranged in the stacking direction,

[0020] The plurality of first contact portions and the plurality of second contact portions are electrically connected at overlapping portions of the first main line portion and the second main line portion, respectively, and

[0021] A waterproof portion is also provided for sealing the overlapping portion in a watertight manner.

[0022] Beneficial effects of the present invention

[0023] According to a bus bar module of one embodiment of the present invention, 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, the first circuit body and the second circuit body (hereinafter also referred to as "main line") formed by the flexible substrate are integrated. 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.

[0024] According to the bus bar module having the above configuration, the first circuit body and the second circuit body are prepared as independent 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 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) installation equipment, the first circuit body and the second circuit body can 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.

[0025] According to the bus bar module having the above configuration, since the first circuit body and the second circuit body are prepared as independent bodies and then electrically connected to each other, when the bus bar module is exposed to water or the like, liquid such as water may enter the overlapping portion (between the first main line portion and the second main line portion) of the first circuit body and the second main line portion of the second circuit body. However, since the bus bar module includes the waterproof portion that seals the overlapping portion in a watertight manner, the occurrence of a problem of conduction (short circuit) of adjacent connection portions by liquid can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a perspective view of a bus bar module according to a first embodiment of the present invention.

[0027] Figure 2 It shows Figure 1 A perspective view of a battery assembly into which a bus bar module is to be assembled is shown.

[0028] 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.

[0029] Figure 4 It shows Figure 3 A perspective view showing a state in which a first circuit body and a second circuit body are connected and accommodated in a bracket.

[0030] 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).

[0031] Figure 6 is a perspective view showing a bus bar module according to a second embodiment of the present invention.

[0032] Figure 7 It shows Figure 6 A perspective view of a battery assembly into which a bus bar module is to be assembled is shown.

[0033] Figure 8 It is shown that when the Figure 6 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.

[0034] Fig. 9 It is shown Figure 8 A perspective view showing a state in which a first circuit body and a second circuit body are connected and accommodated in a bracket.

[0035] Fig.10 yes Fig. 9A 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

[0036] <First Embodiment>

[0037] The bus bar module 10 according to the first embodiment of the present invention will be described below with reference to the accompanying drawings. The bus bar module 10 according to the present 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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. Any pair of the left and right first circuit bodies 20A and the left and right second circuit bodies 20B are connected 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.

[0043] 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 ).

[0044] 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, so that 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. Figures 3 to 5As shown, the size of the circuit connection part 23 of the first circuit body 20A in the width direction (left-right direction) is larger than the size of the second circuit body 20B in the width direction. The detailed structure of the circuit connection part 23 of each of the first circuit body 20A and the second circuit body 20B and the connection process between the circuit connection parts 23 will be described later.

[0045] 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 a 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. However, each of the first circuit body 20A and the second circuit body 20B may be a "double-sided FPC".

[0046] 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).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Hereinafter, the detailed structures of the circuit connection portion 23 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 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) 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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. In addition, 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.

[0058] After 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, the coating material 32 is applied to the edge portion 23a (more specifically, three of the four sides) of the circuit connecting portion 23 having a substantially rectangular U shape so as to close the gap between the circuit connecting portion 23 of the first circuit body 20A and the circuit connecting portion 23 of the second circuit body 20B (see Figure 4 and 5 ). This makes it possible to prevent liquid such as water from entering between the circuit connection portion 23 of the first circuit body 20A and the circuit connection portion 23 of the second circuit body 20B. That is, the coating material 32 can prevent the occurrence of a problem in which the adjacent contact portions 25 are electrically conductive (short-circuited) through the liquid. The coating material 32 is, for example, a known waterproof material or a moisture-proof material.

[0059] The coating material 32 may be applied to all four sides or only one side of the edge portion 23a. Instead of the connection between the dummy contact portion 27 of the first circuit body 20A and the dummy contact portion 27 of the second circuit body 20B, the first circuit body 20A and the second circuit body 20B may be mechanically integrated with each other by the coating material 32. Note that the order of the operation of applying the coating material 32 to the edge portion 23a and the operation of accommodating the first circuit body 20A and the second circuit body 20B in the bracket 60 (circuit body holding portion 61) is not important.

[0060] Next, the bracket 60 will be described. The bracket 60 is a resin molded product, and Figure 1As 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.

[0061] 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 ).

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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).

[0067] 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.

[0068] 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 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 to each other. 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.

[0069] 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.

[0070] According to the bus bar module 10 of the present embodiment, since the first circuit body 20A and the second circuit body 20B are prepared as separate bodies and then electrically connected to each other, when the bus bar module 10 is exposed to water or the like, liquid such as water may enter the overlapping 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 (between the circuit connection portion 23 of the first circuit body 20A and the circuit connection portion 23 of the second circuit body). However, since the coating material 32 is applied to the edge portion 23a of the circuit connection portion 23 of the first circuit body 20A and the second circuit body 20B to close the gap between the circuit connection portion 23 of the first circuit body 20A and the circuit connection portion 23 of the second circuit body 20B, the liquid may be prevented from entering the gap between the circuit connection portions 23. Therefore, the problem that the adjacent contact portions 25 are conducted (short-circuited) by the liquid may be prevented from occurring in the bus bar module 10.

[0071] <Second Embodiment>

[0072] Hereinafter, a bus bar module 110 according to a second embodiment of the present invention will be described with reference to the accompanying drawings. The bus bar module 110 according to the present embodiment is assembled to a long battery assembly 101 (see FIG. Figure 7 , in which a plurality of single cells are stacked and arranged) is used, and the battery assembly 101 is used as a driving power source mounted on an electric vehicle.

[0073] In the following, for the convenience of description, the definitions of “front”, “rear”, “left”, “right”, “upper” and “lower” are as follows: Figure 6 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 102 forming the battery assembly 101 (see Figure 6 and 7 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 110 is mounted on the vehicle.

[0074] First, as a preparation for describing the bus bar module 110, reference will be made to Figure 7 The battery assembly 101 to which the bus bar module 110 is attached is described. Figure 7 As shown, the battery assembly 101 is formed by stacking a plurality of rectangular flat-plate-shaped cells 102 extending in the up-down direction and the left-right direction in the front-to-back direction. Each of the plurality of cells 102 includes a battery body 3 having a rectangular flat plate shape, and a positive electrode 104 and a negative electrode 105 protruding upward from two portions in the left-right direction of an upper surface 106 of the battery body 103.

[0075] In the battery assembly 101, a plurality of single cells 102 are stacked by reversing the positions of the positive electrodes 104 and the negative electrodes 105 of the single cells 102 adjacent to each other in the front-to-back direction in the left-to-right direction, so that the positive electrodes 104 and the negative electrodes 105 are alternately arranged in the front-to-back direction at the left and right ends of the upper surface of the battery assembly 101.

[0076] The bus bar module 110 will be described below. Figure 6 , 8 As shown in FIG. 9 , the bus bar module 110 includes: a long circuit body 120 extending in the front-to-back direction (see FIG. Figure 6 and 8 ); respectively connected to the circuit body 120 of the plurality of branch line portions 122 (see Figure 8 ) of a plurality of bus bars 140 (see Figure 6 ); a plurality of electronic components 150 are mounted on a plurality of branch line portions 122 (see Figure 8 ); holding the circuit body 120 and the bus bar 140 of the bracket 160 (see Figure 6 and Figure 8 ); and a cover 170 covering the circuit body 120 (see Figure 6 The main line portion 121 and the branch line portion 122 of the circuit body 120 (see Figure 8 ) are also called "main line" and "branch line" respectively.

[0077] The circuit body 120 is made of a flexible substrate (FPC) that is easy to bend. Figure 6 and Figure 8 It can be understood that the circuit body 120 includes a pair of left and right first circuit bodies 120A and a pair of left and right second circuit bodies 120B. The left and right first circuit bodies 120A extend in the front-to-back direction and are spaced apart in the left-to-right direction. The left and right second circuit bodies 120B are respectively connected to the rear sides of the pair of left and right first circuit bodies 120A and extend in the front-to-back direction. Any one of the pair of left and right first circuit bodies 120A and the pair of left and right second circuit bodies 120B is connected to the left and right first circuit bodies 120A by a connecting portion 128 (see Figure 6 ) is connected in the left-right direction. A connector 129 (see FIG. 1 ) electrically connected to an external voltage detection device (not shown) or the like Figure 6 ) is installed on the lower surface of the connecting portion 128.

[0078] Each of the first circuit body 120A and the second circuit body 120B includes a strip-shaped main line portion 121 extending in the front-rear direction, and at least one (in this example, a plurality of) branch line portions 122 extending from at least one (in this example, a plurality of) portions in the front-rear direction of the main line portion 121 to branch outward in the left-right direction (see Figure 8). In this example, the branch line portion 122 extends from the main line portion 121 in a manner having a U-shaped bent shape. Since the branch line portion 122 has a U-shaped bent shape, the flexibility of the branch line portion 122 in the front-rear direction, the left-right direction, and the up-down direction is improved. The contact portion 124 made of metal is provided on the upper surface of the end portion of the branch line portion 122 so as to be exposed to the outside (see Figure 8 ).

[0079] By connecting the circuit connection portion 123 provided at the rear end portion of the main line portion 121 of the first circuit body 120A and the circuit connection portion 123 provided at the front end portion of the main line portion 121 of the second circuit body 120B, the main line portion 121 of the first circuit body 120A and the main line portion 121 of the second circuit body 120B are continuous with each other and extend in a row in the front-rear direction to form the circuit body 120. The detailed structure of the circuit connection portion 123 of each of the first circuit body 120A and the second circuit body 120B and the connection process between the circuit connection portions 123 will be described later.

[0080] The entire surface of each of the first circuit body 120A and the second circuit body 120B is made of a resin layer except for a portion where the contact portion 124 provided on the branch line portion 122 is exposed (see Figure 8 ) and a portion in which a contact portion 125 provided on a circuit connecting portion 123 described later is exposed (see Figure 8 Each of the first circuit body 120A and the second circuit body 120B includes a plurality of wiring patterns 126 therein (see Figure 8 ). Each wiring pattern 126 is a copper conductor extending in a strip shape, and extends along the main line portion 121 and the branch line portion 122. Each of the first circuit body 120A and the second circuit body 120B is a so-called "single-sided flexible substrate (single-sided FPC)" having a single wiring layer. A plurality of wiring patterns 126 are arranged on a single wiring layer of each of the first circuit body 120A and the second circuit body 120B. However, each of the first circuit body 120A and the second circuit body 120B may be a "double-sided FPC".

[0081] At a position where the circuit connection portion 123 of the first circuit body 120A and the circuit connection portion 123 of the second circuit body 120B are connected to each other, at least one (in this example, six) wiring patterns 26 belonging to the first circuit body 120A and at least one (in this example, six) wiring patterns 126 belonging to the second circuit body 120B are independently connected to each other (see Figure 8 , details given later).

[0082] Each of the plurality of wiring patterns 126 included in the first circuit body 120A and the second circuit body 120B is electrically connected to a connector 129 mounted on the connecting portion 128, starting from a contact portion 124 of a corresponding branch portion 122, sequentially passing through the inside of the corresponding branch portion 122, the main line portion 121, and the connecting portion 128. Therefore, the contact portions 124 of the branch portions 122 belonging to the first circuit body 120A and the second circuit body 120B are individually conductively connected to an external voltage detection device via the connector 129 mounted on the connecting portion 128.

[0083] The end portion of the branch line portion 122 is mounted with an electronic component 150 and is connected to an elongated flat plate-shaped metal connection terminal 141 connected to the bus bar 140 (see FIG. Figure 8 The connection terminal 141 may be a portion of the bus bar 140 made of metal and having a substantially rectangular flat plate shape (see Figure 6 ), or may be a member separated from the bus bar 140 and joined to the bus bar 140 by welding or the like. The electronic component 150 is typically a sheet-type fuse. The electronic component 150 is mounted on the end portion of the branch portion 122 by welding or the like so as to connect the contact portion 124 of the branch portion 122 with the connection terminal 141. Therefore, at each branch portion 122, the contact portion 124 (i.e., the wiring pattern 126 extending from the contact portion 124) and the connection terminal 141 (i.e., the bus bar 140) are electrically connected via the electronic component 150.

[0084] In a state before the circuit connecting portion 123 of the first circuit body 120A and the circuit connecting portion 123 of the second circuit body 120B are connected to each other (i.e., in a state where both the first circuit body 120A and the second circuit body 120B are in an independent state), mounting of the electronic component 150 to the branch line portion 122 is performed for each of the branch line portion 122 belonging to the first circuit body 120A and the branch line portion 122 belonging to the second circuit body 120B. Therefore, compared with a case where the first circuit body 120A and the second circuit body 120B are formed of a common (single) flexible substrate, the length of each of the first circuit body 120A and the second circuit body 120B in the front-rear direction is shortened, and thus a large mounting device is not required. In other words, since the first circuit body 120A and the second circuit body 120B are separate bodies, regardless of the length and size of the long circuit body 120 obtained by connecting the circuit connecting part 123 of the first circuit body 120A and the circuit connecting part 123 of the second circuit body 120B to each other, the electronic component 150 can be appropriately installed on each branch line part 122, and the manufacturing cost of the bus bar module 110 can be reduced.

[0085] The detailed structures of the circuit connection part 123 of the first circuit body 120A and the circuit connection part 123 of the second circuit body 120B and the connection procedure between the circuit connection parts 123 will be described below. Figure 8 As shown, on the upper surface of the circuit connection part 123 of the first circuit body 120A, a plurality of (in this example, six) contact parts (pads) 125 made of metal are arranged to be spaced apart in the front-back direction and exposed to the outside. A wiring pattern 126 extends from each contact part 125. More specifically, for each of the three contact parts 125 on the front side (the base end side of the circuit connection part 123) of the six contact parts 125, the wiring pattern 126 extends from the contact part 125 to one side (the left side) in the width direction (left-right direction) of the main line part 121 of the first circuit body 120A, and then extends forward. For each of the three contact parts 125 on the rear side (the end side of the circuit connection part 123) of the six contact parts 125, the wiring pattern 126 extends from the contact part 125 to the other side (the right side) in the width direction (left-right direction) of the main line part 121 of the first circuit body 120A, and then extends forward.

[0086] In this way, by arranging the extensions of the plurality of wiring patterns 126 extending from the plurality of contact portions 125 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 126 extending from the contact portions 125, miniaturization of the circuit connection portion 123 (i.e., the first circuit body 120A), and the like. On the upper surface of the circuit connection portion 123 of the first circuit body 120A, a dummy contact portion (pad) 127 made of metal is provided to be exposed to the outside at a position that does not interfere with the contact portion 125 and the wiring pattern 126. The dummy contact portion 127 is not connected (electrically connected) to the wiring pattern 126 (i.e., the bus bar 140). In the circuit connection portion 123 of the first circuit body 120A, hole portions 131 penetrating in the thickness direction (up-down direction) of the circuit connection portion 123 are respectively formed at a plurality of positions (in this example, two positions) that do not interfere with the contact portion 125, the wiring pattern 126, and the dummy contact portion 127.

[0087] On the lower surface of the circuit connection part 123 of the second circuit body 120B, corresponding to the plurality of contact parts 125 of the first circuit body 120A, a plurality of (in this example, six) contact parts (pads) 125 made of metal are arranged in a spaced manner in the front-back direction and exposed to the outside. A wiring pattern 126 extends separately from each contact part 125. More specifically, for each of the three contact parts 125 on the front side (the end side of the circuit connection part 123) of the six contact parts 125, the wiring pattern 126 extends from the contact part 125 to the other side (right side) in the width direction (left-right direction) of the main line part 121 of the second circuit body 120B, and then extends backward. For each of the three contact parts 125 on the rear side (the base end side of the circuit connection part 123) of the six contact parts 125, the wiring pattern 126 extends from the contact part 125 to one side (left side) in the width direction (left-right direction) of the main line part 121 of the second circuit body 120B, and then extends backward.

[0088] In this way, by arranging the extensions of the plurality of wiring patterns 126 extending from the plurality of contact portions 125 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 126 extending from the contact portions 125, miniaturization of the circuit connection portion 123 (i.e., the second circuit body 120B), etc. On the lower surface of the circuit connection portion 123 of the second circuit body 120B, a dummy contact portion (pad) 127 made of metal is provided to be exposed to the outside at a position that does not interfere with the contact portion 125 and the wiring pattern 126, corresponding to the dummy contact portion 127 of the first circuit body 120A. The dummy contact portion 127 is not connected (electrically connected) to the wiring pattern 126 (i.e., the bus bar 140). In the circuit connecting portion 123 of the second circuit body 120B, corresponding to the multiple hole portions 131 of the first circuit body 120A, the hole portions 131 penetrating in the thickness direction (up and down direction) of the circuit connecting portion 123 are respectively formed at multiple positions (in this example, two positions) that do not interfere with the contact portion 125, the wiring pattern 126 and the dummy contact portion 127.

[0089] In the operation of connecting the circuit connection portion 123 of the first circuit body 120A and the circuit connection portion 123 of the second circuit body 120B, first, in a state where the circuit connection portion 123 of the first circuit body 120A is located below the circuit connection portion 123 of the second circuit body 120B, the plurality of contact portions 125 of the first circuit body 120A and the plurality of contact portions 125 of the second circuit body 120B are welded independently, and the dummy contact portion 127 of the first circuit body 120A and the dummy contact portion 127 of the second circuit body 120B are welded. Typically, welding can be performed by a method (so-called pulse heating method) in which paste solder is sandwiched between the contact portions 125 arranged facing each other in the up-down direction and between the dummy contact portions 127 arranged facing each other in the up-down direction, 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 123 of the first circuit body 120A and the circuit connection portion 123 of the second circuit body 120B may be performed using a conductive adhesive instead of the above-mentioned soldering.

[0090] Therefore, at the position where the circuit connection part 123 of the first circuit body 120A and the circuit connection part 123 of the second circuit body 120B are connected to each other, the plurality of wiring patterns 126 belonging to the first circuit body 120A and the plurality of wiring patterns 126 belonging to the second circuit body 120B are electrically connected to each other respectively and independently, and mechanically integrated. In addition, the dummy contact part 127 of the first circuit body 120A and the dummy contact part 127 of the second circuit body 120B are mechanically integrated with each other using solder, a conductive adhesive, etc. Therefore, the first circuit body 120A and the second circuit body 120B can be more firmly integrated.

[0091] Next, the adhesive tape 132 is respectively disposed below the first circuit body 120A and above the second circuit body 120B, and the adhesive tape 132 is attached to the outer surface of the circuit connection portion 123 to cover the edge portion 123a of the circuit connection portion 123 of the first circuit body 120A and the second circuit body 120B. Therefore, the gap between the circuit connection portion 123 of the first circuit body 120A and the circuit connection portion 123 of the second circuit body 120B is covered by the adhesive tape 132, and liquid such as water can be prevented from entering between the circuit connection portion 123 of the first circuit body 120A and the circuit connection portion 123 of the second circuit body 120B. That is, the adhesive tape 132 can prevent the occurrence of the problem of adjacent contact portions 125 being conducted (short circuit) by liquid. The adhesive tape 132 is, for example, a known waterproof tape or protective tape.

[0092] Next, the plurality of protrusions 161a are sequentially inserted from above through the plurality of hole portions 132a of the lower tape 132, the plurality of hole portions 131 of the first circuit body 120A, the plurality of hole portions 131 of the second circuit body 120B, and the plurality of hole portions 132a of the upper tape 132 (see Figure 8 ). Therefore, in a state where the circuit connecting portion 123 of the first circuit body 120A and the circuit connecting portion 123 of the second circuit body 120B are connected to each other, the first circuit body 120A and the second circuit body 120B are accommodated in the bracket 160 (circuit body holding portion 161). When an unintentional external force is applied to the circuit body 120 (more specifically, the main line portion 121 of the first circuit body 120A and the main line portion 121 of the second circuit body 120B) after the connection, the external force is received by the protrusion 161a. Therefore, it is possible to prevent the external force from being applied to the connection portion of the contact portion 125 (wiring pattern 126) of the first circuit body 120A and the contact portion 125 (wiring pattern 126) of the second circuit body 120B. Therefore, the reliability of the electrical connection between the first circuit body 120A and the second circuit body 120B can be improved.

[0093] Next, the bracket 160 will be described. The bracket 160 is a resin molded product, and Figure 6 As shown, a pair of left and right strip-shaped circuit body holding parts 161 spaced apart in the left-right direction and extending in the front-back direction are integrally included, and a plurality of coupling parts 162 coupling the pair of left and right circuit body holding parts 161 in the left-right direction at a plurality of positions in the front-back direction. A pair of left and right first circuit bodies 120A (main line part 121+branch line part 122) and a pair of left and right second circuit bodies 120B (main line part 121+branch line part 122) of the circuit body 120 are placed on the pair of left and right circuit body holding parts 161, respectively.

[0094] Specifically, each of a pair of circuit body retaining portions 161 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 retaining portions 161 can extend and contract in the front-to-back direction. As described above, a plurality of (two) protrusions 161a are provided on the bottom wall of the circuit body retaining portion 161 (see Figure 8 ).

[0095] For each of the pair of left and right circuit body holding portions 161, the bus bar holding portion 164 (see Figure 6) 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 164 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 161. Since each bus bar holding portion 164 is provided in the corresponding split body, the interval in the front-to-back direction between the bus bar holding portions 164 adjacent to each other in the front-to-back direction can be changed by the action of the extension and contraction portion.

[0096] Each bus bar holding portion 164 accommodates a corresponding bus bar 140. When the bracket 160 is attached to the battery assembly 101, the bus bars 140 accommodated in the bus bar holding portions 164 are conductively connected to the corresponding positive electrodes 104 and negative electrodes 105 adjacent to each other in the front-rear direction on the upper surface of the battery assembly 101.

[0097] Next, the cover 170 will be described. The cover 170, which is a resin molded product, is used to cover the circuit body 120, that is, the first circuit body 120A (main line portion 121 + branch line portion 122) and the second circuit body 120B (main line portion 121 + branch line portion 122) placed on a pair of left and right circuit body holding portions 161 of the bracket 160 that is long in the front-rear direction (see Figure 6 ). Therefore, if Figure 6 As shown, the cover 170 has a strip shape formed to be long in the front-rear direction.

[0098] In the state where the busbar module 110 is attached to the battery assembly 101, in the battery assembly 101, a plurality of stacked cells 102 are electrically connected in series via a plurality of busbars 140. In addition, each busbar 140 is conductively connected to an external voltage detection device in turn via an electronic component 150 mounted on a corresponding branch portion 122, a wiring pattern 126 extending from the corresponding branch portion 122 (contact portion 124), and a connector 129 mounted on a connecting portion 128. Therefore, the voltage (potential) of each busbar 140 can be detected individually by an external voltage detection device. When an overcurrent equal to or greater than the rated current flows in the electronic component 150 for some reason, the fuse function of the electronic component 150 causes the electronic component 150 to cut off the electrical connection between the busbar 140 and the wiring pattern 126. Therefore, an overcurrent is prevented from flowing into the voltage detection device, so that the voltage detection device can be protected.

[0099] In the use state of the battery assembly 101 to which the bus bar module 110 is attached, each single battery 102 constituting the battery assembly 101 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 101 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 batteries 102, for each manufactured battery assembly 101, the size of the battery assembly 101 in the stacking direction (front-to-back direction) generally varies (manufacturing variations may occur).

[0100] In this regard, in the bus bar module 110, even if the battery assembly 101 extends and contracts in the stacking direction (front-to-back direction) due to thermal deformation of each single battery 102 and manufacturing variations of the battery assembly 101, since each of the multiple extending and contracting portions of the bracket 160 extends and contracts in the front-to-back direction, and each branch portion 122 formed by the flexible substrate is easily bent, the extension and contraction caused by the thermal deformation and manufacturing variations of the battery assembly 101 can be easily absorbed.

[0101] As described above, according to the bus bar module 110 of the present embodiment, the first circuit body 120A and the second circuit body 120B (main line) formed by the flexible substrate are integrated by electrically connecting the wiring pattern 126 of the first circuit body 120A and the wiring pattern 126 of the second circuit body 120B at the overlapping portion (circuit connection portion 123) of the main line portion 121 of the first circuit body 120A and the main line portion 121 of the second circuit body 120B. In other words, the first circuit body 120A and the second circuit body 120B are electrically connected to each other. In addition, the branch line portion 122 (branch line) extends to branch from the main line portion 121 of the first circuit body 120A and the main line portion 121 of the second circuit body 120B. Therefore, when the battery assembly 101 expands and contracts in the stacking direction (front-rear direction) due to thermal deformation of each single cell 102, each bus bar 140 can be moved in the stacking direction of the single cell 102 by bending the branch line, etc. Similarly, by bending the branch line, etc., the dimensional change of the battery assembly 101 in the stacking direction (front-to-back direction) caused by the assembly tolerance of the single cell 102 can be absorbed. In other words, the bus bar module 110 according to the present embodiment can easily cope with the expansion and contraction of the battery assembly 101 and manufacturing changes 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 101 is improved. Therefore, the bus bar module 110 according to the present embodiment can be easily assembled to the battery assembly 101, and has better adaptability to the deformation and manufacturing changes of the battery assembly 101 than the bus bar module in the above-mentioned related art.

[0102] In addition, the first circuit body 120A and the second circuit body 120B are prepared as separate bodies and then electrically connected to each other. Therefore, compared with the case where the first circuit body 120A and the second circuit body 120B are formed by a single continuous flexible substrate, the length of the first circuit body 120A and the second circuit body 120B in the stacking direction (front-back direction) is shortened. Therefore, when the electronic component 150 is attached (i.e., installed) to each branch line portion 122, 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 120A and the second circuit body 120B is not suitable for general (universal) installation equipment, after the electronic component 150 is appropriately installed on the branch line portion 122 for each of the first circuit body 120A and the second circuit body 120B, the first circuit body 120A and the second circuit body 120B can also be connected to each other. Therefore, the manufacturing cost of the bus bar module 110 can be reduced.

[0103] According to the bus bar module 110 of the present embodiment, since the first circuit body 120A and the second circuit body 120B are prepared as independent bodies and then electrically connected to each other, when the bus bar module 110 is exposed to water or the like, liquid such as water may enter the overlapping portion 123 of the main line portion 121 of the first circuit body 120A and the main line portion 121 of the second circuit body (between the circuit connection portion 123 of the first circuit body 120A and the circuit connection portion 123 of the second circuit body 120B). However, the adhesive tape 132 is attached to the outer surfaces of the first circuit body 120A and the second circuit body 120B to cover the edge portion 123a of the circuit connection portion 123 of the first circuit body 120A and the second circuit body 120B, so that the liquid may be prevented from entering the gap between the circuit connection portions 123. Therefore, the occurrence of the problem that the adjacent contact portions 125 are conducted (short-circuited) by the liquid may be prevented in the bus bar module 110.

[0104] The present invention has been described based on the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, and can be appropriately modified, improved, etc. In addition, the materials, shapes, sizes, quantities, arrangement positions, etc. of the components in the above-mentioned embodiments are freely selected and are not limited as long as the present invention can be achieved.

[0105] Here, the features of the above-described embodiments of the bus bar module according to the present invention will be briefly summarized and listed in the following [1] to [3]. [1]

[0107] A busbar module (10, 110) to be attached to a battery assembly (1, 101), wherein a plurality of single batteries (2) are stacked in the battery assembly (1, 101), and the busbar module (10, 110) comprises:

[0108] A first circuit body (20A, 120A) formed of a flexible substrate having a first wiring pattern (26, 126) and including a first main line portion (21, 121) extending along a stacking direction of a plurality of single cells (2, 102) and a first branch line portion (22, 122) extending to branch from the first main line portion (21, 121);

[0109] A second circuit body (20B, 120B) formed of a flexible substrate having a second wiring pattern (26, 126) and including a second main line portion (21, 121) and a second branch line portion (22, 122), the second main line portion (21, 121) extending in a stacking direction, and the second branch line portion (22, 122) extending to branch from the second main line portion (21, 121);

[0110] Bus bars (40, 140), each bus bar connected to electrodes (4, 5, 104, 105) of a plurality of single cells (2);

[0111] An electronic component (50, 150) attached to the first branch line portion (22, 122) and the second branch line portion (22, 122) such that the first wiring pattern (26, 126) and the second wiring pattern (26, 126) are connected to the corresponding bus bars (40, 140); and

[0112] A bracket (60, 160) is capable of extending and contracting along a stacking direction and is configured to hold a first circuit body (20A, 120A), a second circuit body (20B, 120B) and a bus bar (40, 140), wherein

[0113] The first wiring pattern (26, 126) includes a plurality of first contact portions (25, 125) arranged in a stacking direction,

[0114] The second wiring pattern (26, 126) includes a plurality of second contact portions (25, 125) arranged in the stacking direction,

[0115] A plurality of first contact portions (25, 125) and a plurality of second contact portions (25, 125) are electrically connected at overlapping portions (23, 123) of the first main line portion (21, 121) and the second main line portion (21, 121), respectively, and

[0116] A waterproof portion (coating material 32, adhesive tape 132) is also provided to seal the overlapping portion in a watertight manner.

[0117] According to the bus bar module having the configuration of [1] above, 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 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 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, 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 to the battery assembly and has better adaptability to deformation and manufacturing changes of the battery assembly.

[0118] 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 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 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) 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.

[0119] According to the bus bar module having the above configuration, since the first circuit body and the second circuit body are prepared as separate bodies and then electrically connected to each other, when the bus bar module is exposed to water or the like, liquid such as water may enter the overlapping portion (between the first main line portion and the second main line portion) of the first circuit body and the second main line portion of the second circuit body. However, since the bus bar module includes a waterproof portion that seals the overlapping portion in a watertight manner, the occurrence of a problem of conduction (short circuit) of adjacent connection portions by liquid can be prevented. [2]

[0121] In the busbar module (10) according to the above [1],

[0122] The waterproof portion is a coating material (32) applied to close at least a portion of the gap at the edge portion (23a) of the overlapped portion.

[0123] According to the bus bar module having the above-mentioned [2] configuration, the coating material is applied to close at least a portion of the gap of the edge portion of the overlapping portion of the first circuit body and the second circuit body, thereby preventing liquid from entering the gap. [3]

[0125] In the busbar module (110) according to the above [1],

[0126] The waterproof portion is a tape (132) attached to the outer surface of the overlapping portion to cover the edge portion (123a) of the overlapping portion.

[0127] According to the bus bar module having the above-mentioned [3] configuration, the tape is attached to the outer surface of the overlapping portion to cover the edge portion of the overlapping portion of the first circuit body and the second circuit body, thereby preventing liquid from entering the gap of the overlapping portion.

[0128] Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to one skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

[0129] This application is based on the Japanese patent application filed on November 30, 2022 (Japanese patent application No. 2022-192294), the contents of which are incorporated herein by reference.

[0130] Industrial Applicability

[0131] According to the present invention, 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 can be provided. The present invention having such an effect is useful for a bus bar module.

[0132] Reference numerals list

[0133] 1.101: Battery components

[0134] 2.102: Single battery

[0135] 4. 104: Positive electrode (electrode)

[0136] 5.105: Negative electrode (electrode)

[0137] 10, 110: Busbar module

[0138] 20A, 120A: First circuit body

[0139] 20B, 120B: Second circuit body

[0140] 21, 121: Main line part (first main line part, second main line part)

[0141] 22, 122: Branch line section (first branch line section, second branch line section)

[0142] 23, 123: Circuit connection part (overlapping part)

[0143] 23, 123a: Edge

[0144] 25, 125: Contact part (first contact part, second contact part)

[0145] 26, 126: Wiring pattern (first wiring pattern, second wiring pattern)

[0146] 31, 131: hole portion (first hole portion, second hole portion)

[0147] 32: Coating material (waterproof part)

[0148] 132: Tape (waterproof part)

[0149] 40, 140: Busbar

[0150] 50, 150: Electronic components

[0151] 60, 160: Bracket

[0152] 61a, 161a: 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 includes a plurality of first contact portions arranged in the stacking direction, wherein the second wiring pattern includes a plurality of second contact portions arranged in the stacking direction, wherein the plurality of first contact portions and the plurality of second contact portions are electrically connected at overlapping portions of the first main line portion and the second main line portion, respectively, and Therein, a waterproof portion is also provided, which seals the overlapping portion in a watertight manner.

2. The bus bar module according to claim 1, in, The waterproof portion is a coating material applied to close at least a portion of a gap at an edge portion of the overlapping portion.

3. The bus bar module according to claim 1, in, The waterproof portion is a tape attached to an outer surface of the overlapping portion to cover an edge portion of the overlapping portion.

Images