Bus bar module

Abstract

To provide a bus bar module which is excellent in the assembling performance to a battery aggregate and in the followability to deformation or manufacturing variations of the battery aggregate.SOLUTION: A bus bar module 10 to be attached to a battery aggregate 1 includes: a first circuit body 20A having a first wire pattern 26; a second circuit body 20B having a second wire pattern 26; and an electronic component 50 attached to first and second branch line parts 22 to connect the first and second wire patterns 26 and a bus bar 40 to each other. An overlapping part 23 of the first and second main lines 21 is electrically connected to the first and second wire patterns 26. In the first and second wire patterns 26, first and second wire parts extend from one of a plurality of first and second connection parts 25 lining in the lamination direction to one side of the intersection direction intersecting with the lamination direction, and extend from the other of the first and second connection parts 25 to the other side of the intersection direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a bus bar module.

Background Art

[0002] Conventionally, a bus bar module has been used, for example, to be assembled to a battery assembly (that is, a battery module in which a plurality of battery cells are stacked) as a driving power source mounted on an electric vehicle or a hybrid vehicle (see, for example, Patent Document 1).

[0003] The bus bar module described in Patent Document 1 includes a plurality of bus bars that connect between the positive electrode and the negative electrode between adjacent battery cells stacked thereon, and voltage detection lines that are connected to each of the plurality of bus bars to monitor each battery cell. This voltage detection line is configured to bundle a plurality of electric wires having a general structure in which a core wire is covered with an insulating coating.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, generally, the battery cells constituting the battery assembly expand and contract in the stacking direction due to the operating heat accompanying charge and discharge, the temperature of the external environment, and the like. As a result, the battery assembly (battery module) also deforms so as to expand and contract in the stacking direction of the battery cells. Further, due to the assembly tolerance when stacking a plurality of battery cells, generally, the size of the battery assembly in the stacking direction may differ for each manufactured battery assembly (that is, manufacturing variations may occur). Therefore, generally, the bus bar module is 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.

[0006] However, in the conventional bus bar module described above, for example, when the number of stacked battery cells is increased for the purpose of increasing the capacity of the battery assembly, the number of wires constituting the voltage detection line also increases. As a result, when these numerous wires are bundled to form the voltage detection line, the rigidity of the entire voltage detection line (and thus the rigidity of the bus bar module) increases, and it may become difficult to improve the workability (assemblability) of assembling the bus bar module to the battery assembly. For the same reason, there is also a possibility that the bus bar module becomes difficult to expand and contract so as to sufficiently cope with deformation and manufacturing variations of the battery assembly.

[0007] One object of the present invention is to provide a bus bar module that is excellent in assemblability to a battery assembly and in followability to deformation and manufacturing variations of the battery assembly.

Means for Solving the Problems

[0008] In order to achieve the above-described object, the bus bar module according to the present invention is characterized as follows.

[0009] A bus bar module attached to a battery assembly in which a plurality of single cells are stacked, A first circuit body composed of a flexible substrate having a first wiring pattern, having a first main line portion arranged to extend along the 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, A second circuit body composed of a flexible substrate having a second wiring pattern, having a second main line portion arranged to extend along the stacking direction, and a second branch line portion extending so as to branch from the second main line portion, A bus bar that is to be connected to the electrodes of each of the plurality of single cells, Electronic components attached to the first branch line portion and the second branch line portion so as to connect the bus bar corresponding to the first wiring pattern and the second wiring pattern, It is stretchable along the stacking direction and includes a holder that holds the first circuit body, the second circuit body, and the bus bar. The first wiring pattern has a plurality of first contact portions arranged in the stacking direction and first wiring portions extending from each of the plurality of first contact portions, and the first wiring portion extends from one of the first contact portions to one side in the crossing direction that intersects the stacking direction, and the first wiring portion extends from the other first contact portion to the other side in the crossing direction. The second wiring pattern has a plurality of second contact portions arranged in the stacking direction and second wiring portions extending from each of the plurality of second contact portions, and 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. In the overlapping portion of the first main line portion and the second main line portion, the plurality of first contact portions and the plurality of second contact portions are electrically connected to each other. It is a bus bar module.

Effect of the Invention

[0010] According to the bus bar module of the present invention, a first circuit body and a second circuit body (hereinafter also referred to as "main lines") composed of flexible substrates are integrated by electrically connecting a first contact portion of a first wiring pattern and a second contact portion of a second wiring pattern at an overlapping portion between a first main line portion of the first circuit body and a second main line portion of the second circuit body. In other words, the first circuit body and the second circuit body are electrically connected. Further, first branch line portions and second branch line portions (hereinafter also referred to as "branch lines") extend so as to branch from the first main line portion and the second main line portion. Therefore, when the battery assembly expands and contracts in the stacking direction due to thermal deformation of each single battery, the branch lines are bent or the like, so that each bus bar can move in the stacking direction of the single battery. Similarly, by bending the branch lines or the like, variations in the size of the battery assembly in the stacking direction due to assembly tolerances of the single batteries can be absorbed. In other words, the bus bar module of this configuration can easily cope with the expansion and contraction of the battery assembly and manufacturing variations by deforming the branch lines. Here, a flexible substrate generally deforms flexibly with a much smaller force than an electric wire used in the above-described conventional bus bar module even when it contains a large number of circuit structures. Therefore, the assemblability to the battery assembly is improved. Therefore, the bus bar module of this configuration is superior in assemblability to the battery assembly and followability to deformation and manufacturing variations of the battery assembly compared to the above-described conventional bus bar module.

[0011] Furthermore, according to the bus bar module having the above configuration, among the plurality of first contact portions arranged in the stacking direction of the plurality of single cells, a first wiring portion extends from one first contact portion to one side in the crossing direction, and a first wiring portion extends from the other first contact portion to the other side in the crossing direction. Thus, by dispersedly arranging the plurality of first wiring portions extending from the plurality of first contact portions in the crossing direction, it is possible to contribute to an improvement in the degree of freedom of the pattern design of the first wiring portion and a reduction in the size 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. Therefore, compared with the case where the first circuit body and the second circuit body are formed of an integral flexible substrate, the lengths of the first circuit body and the second circuit body in the stacking direction are shortened. Therefore, when attaching (i.e., mounting) electronic components to the first branch portion and the second branch portion, a dedicated large mounting device is not required. In other words, even when the length and size of the final main line to which the first circuit body and the second circuit body are connected are not suitable for a general (universal) mounting device, after appropriately mounting electronic components on the branch circuit bodies using general (universal) mounting devices for each of the first circuit body and the second circuit body, the first circuit body and the second circuit body may be connected, so that the manufacturing cost of the bus bar module can be reduced.

[0012] The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through the embodiments for carrying out the invention described below with reference to the accompanying drawings.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0014] <Embodiment> Hereinafter, with reference to the drawings, the bus bar module 10 according to an embodiment of the present invention will be described. The bus bar module 10 according to the present embodiment is used, for example, to be assembled to a long battery assembly 1 (see FIG. 2; a battery module in which a plurality of single cells are stacked) as a driving power source mounted on an electric vehicle.

[0015] Hereinafter, for convenience of explanation, as shown in FIG. 1 and the like, “front”, “rear”, “left”, “right”, “up” and “down” are defined. The “front-rear direction”, “left-right direction” and “up-down direction” are orthogonal to each other. The front-rear direction coincides with the stacking direction of the plurality of single cells 2 constituting the battery assembly 1 (see FIGS. 1 and 2). Note that these directions are defined for convenience of explanation 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.

[0016] First, as a preparation for explaining the bus bar module 10, the battery assembly 1 to which the bus bar module 10 is attached will be described with reference to FIG. 2. As shown in FIG. 2, the battery assembly 1 is configured by stacking a plurality of rectangular flat single cells 2 extending in the up-down direction and the left-right direction in the front-rear direction. Each of the plurality of single cells 2 includes a rectangular flat battery body 3, a positive electrode 4 and a negative electrode 5 protruding upward from both left and right ends of the upper surface 6 of the battery body 3.

[0017] In the battery assembly 1, the left - right positions of the positive electrodes 4 and negative electrodes 5 of adjacent single cells 2 in the front - rear direction are reversed from each other, so that the positive electrodes 4 and negative electrodes 5 are alternately arranged in the front - rear direction at each of the left - end portion and the right - end portion of the upper surface of the battery assembly 1, and a plurality of single cells 2 are stacked.

[0018] Hereinafter, the bus bar module 10 will be described. As shown in FIGS. 1, 3, and 4, the bus bar module 10 includes a long - sized circuit body 20 (see FIGS. 1 and 3) extending in the front - rear direction, a plurality of bus bars 40 (see FIG. 1) respectively connected to a plurality of branch - line portions 22 (see FIG. 3) of the circuit body 20, a plurality of electronic components 50 (see FIG. 3) respectively mounted on the plurality of branch - line portions 22, a holder 60 (see FIGS. 1 and 3) holding the circuit body 20 and the bus bars 40, and a cover 70 (see FIG. 1) covering the circuit body 20. Note that the main - line portion 21 and the branch - line portions 22 (see FIG. 3) of the circuit body 20 are also called "trunk line" and "branch line", respectively.

[0019] The circuit body 20 is composed of a flexible printed circuit (FPC) that can be easily bent. As can be understood from FIGS. 1 and 3, the circuit body 20 includes a pair of left - right first circuit bodies 20A extending in the front - rear direction with a space therebetween in the left - right direction, and a pair of left - right second circuit bodies 20B respectively connected to the rear sides of the pair of left - right first circuit bodies 20A and extending in the front - rear direction. Either one of the pair of left - right first circuit bodies 20A and the pair of left - right second circuit bodies 20B is connected in the left - right direction by a connecting portion 28 (see FIG. 1). A connector 29 (see FIG. 1) electrically connected to an external voltage detection device (not shown) or the like is mounted on the lower surface of the connecting portion 28.

[0020] 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 outward in the left-right direction from at least one location (in this example, a plurality of locations) in the front-rear direction of the main line portion 21 (see FIG. 3). In this example, each branch line portion 22 extends from the main line portion 21 so as to have a U-shaped curved shape. By having a U-shaped curved shape, the flexibility of the branch line portion 22 in the front-rear, left-right, and up-down directions is enhanced. On the upper surface of the tip of each branch line portion 22, a metal contact portion 24 is provided so as to be exposed to the outside (see FIG. 3).

[0021] 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 portions 21 of the first circuit body 20A and the second circuit body 20B are continuously connected to form a circuit body 20 extending in a row in the front-rear direction. The detailed structure of each circuit connection portion 23 of the first circuit body 20A and the second circuit body 20B and the connection procedure between the circuit connection portions 23 will be described later.

[0022] The entire surface of each of the first circuit body 20A and the second circuit body 20B is composed of a resin layer except for the locations where the contact portion 24 provided on the branch line portion 22 is exposed (see FIG. 3) and the locations where a contact portion 25 (to be described later) provided on the circuit connection portion 23 is exposed (see FIG. 3), and includes a plurality of wiring patterns 26 (see FIG. 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 printed circuit board (single-sided FPC)" having a single wiring layer, and for each of the first circuit body 20A and the second circuit body 20B, a plurality of wiring patterns 26 are arranged in the single wiring layer.

[0023] At the location where the circuit connection parts 23 of the first circuit body 20A and the second circuit body 20B are connected, at least one (six in this example) wiring pattern 26 belonging to the first circuit body 20A and at least one (six in this example) wiring pattern 26 belonging to the second circuit body 20B are connected one-to-one independently of each other (see Fig. 3. Details will be described later).

[0024] The plurality of wiring patterns 26 included in the first circuit body 20A and the second circuit body 20B are each individually electrically connected from the contact part 24 of the corresponding branch line part 22, through the inside of the corresponding branch line part 22, main line part 21, and connecting part 28 in this order, to the connector 29 mounted on the connecting part 28. Thereby, the contact parts 24 of each branch line part 22 belonging to the first circuit body 20A and the second circuit body 20B are individually conductively connected to an external voltage detection device via the connector 29 mounted on the connecting part 28.

[0025] An electronic component 50 is mounted at the tip of each branch line part 22, and an elongated flat plate-shaped metal connection terminal 41 connected to the bus bar 40 is connected (see Fig. 3 etc.). The connection terminal 41 may be a part of a substantially rectangular flat plate-shaped metal bus bar 40 (see Fig. 1), or may be a member separate from the bus bar 40 and joined to the bus bar 40 by soldering or the like. The electronic component 50 is typically a chip fuse. The electronic component 50 is mounted at the tip of the branch line part 22 by soldering or the like so as to connect the contact part 24 of the branch line part 22 and the connection terminal 41. Thereby, for each branch line part 22, the contact part 24 (that is, the wiring pattern 26 extending from the contact part 24) and the connection terminal 41 (that is, the bus bar 40) are electrically connected via the electronic component 50.

[0026] The mounting of such electronic components 50 to the branch portions 22 is performed individually on the branch portion 22 belonging to the first circuit body 20A and the branch portion 22 belonging to the second circuit body 20B in a state before the circuit connection portions 23 of the first circuit body 20A and the second circuit body 20B are connected (that is, each of the first circuit body 20A and the second circuit body 20B is in a single state). Therefore, compared with the case where the first circuit body 20A and the second circuit body 20B are constituted 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-rear direction becomes shorter, and thus 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 portions 23 of the first circuit body 20A and the second circuit body 20B, the electronic components 50 can be properly mounted on each branch portion 22, and the manufacturing cost of the bus bar module 10 can be reduced.

[0027] Hereinafter, the detailed structure of each circuit connection portion 23 of the first circuit body 20A and the second circuit body 20B and the connection procedure between the circuit connection portions 23 will be described. As shown in FIGS. 3 and 5, on the upper surface of the circuit connection portion 23 of the first circuit body 20A, a plurality (six in this example) of metal contact portions (pads) 25 are provided so as to be arranged at intervals in the front-rear direction and to be exposed to the outside. Wiring patterns 26 extend individually from each contact portion 25. More specifically, for each of the three contact portions 25 on the front side (the base end side of the circuit connection portion 23) among 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 first circuit body 20A, and then extends forward. For each of the three contact portions 25 on the rear side (the tip end side of the circuit connection portion 23) among 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 first circuit body 20A, and then extends forward.

[0028] In this way, by dispersing and arranging in the left-right direction the extending portions of the plurality of wiring patterns 26 extending from the plurality of contact portions 25, it is possible to contribute to an improvement in the degree of freedom of the pattern design of the extending portions 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 metal dummy contact portion (land) 27 is provided so as to be exposed to the outside at a position where it 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, through holes 31 penetrating in the thickness direction (up-down direction) of the circuit connection portion 23 are formed at a plurality of positions (two positions in this example) that do not interfere with the contact portion 25, the wiring pattern 26, and the dummy contact portion 27.

[0029] In the circuit connection portion 23 of the first circuit body 20A, at each of the positions (five positions) between adjacent contact portions 25 among the plurality of (six) contact portions 25 arranged in the front-rear direction, slit-shaped through holes (hereinafter referred to as "isolation holes 32") penetrating in the thickness direction (up-down direction) of the circuit connection portion 23 are formed so as to extend in the left-right direction (see FIGS. 3 and 5). Thereby, when the bus bar module 10 is exposed to water or the like, it is possible to suppress the occurrence of a problem in which conduction (short circuit) occurs between adjacent contact portions 25 due to moisture. Further, two of the five isolation holes 32 communicate with two of the holes 31, respectively. Thereby, the diameter of the isolation holes 32 is enlarged, and the above-described short-circuit suppression effect can be further enhanced.

[0030] On the lower surface of the circuit connection portion 23 of the second circuit body 20B, a plurality (six in this example) of metal contact portions (pads) 25 are provided so as to be arranged at intervals in the front-rear direction and to be exposed to the outside, corresponding to the plurality of contact portions 25 of the first circuit body 20A. Wiring patterns 26 extend individually from each contact portion 25. More specifically, for each of the three contact portions 25 on the front side (the tip side of the circuit connection portion 23) among 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 rearward. For each of the three contact portions 25 on the rear side (the base end side of the circuit connection portion 23) among 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 rearward.

[0031] In this way, by dispersing and arranging the extending portions of the plurality of wiring patterns 26 extending from the plurality of contact portions 25 in the left-right direction, it is possible to contribute to an improvement in the degree of freedom of the pattern design of the extending portions of the wiring patterns 26 extending from the contact portions 25, miniaturization of the circuit connection portion 23 (that is, the second circuit body 20B), and the like. On the lower surface of the circuit connection portion 23 of the second circuit body 20B, a metal dummy contact portion (land) 27 is provided at one location that does not interfere with the contact portions 25 and the wiring patterns 26, corresponding to the dummy contact portion 27 of the first circuit body 20A, so as to be exposed to the outside. The dummy contact portion 27 is not connected (electrically connected) to the wiring pattern 26 (that is, the bus bar 40). In the circuit connection portion 23 of the second circuit body 20B, corresponding to the plurality of hole portions 31 of the first circuit body 20A, hole portions 31 penetrating in the thickness direction (up-down direction) of the circuit connection portion 23 are formed at a plurality of locations (two locations in this example) that do not interfere with the contact portions 25, the wiring patterns 26, and the dummy contact portion 27.

[0032] In the circuit connection portion 23 of the second circuit body 20B, similar to the isolation hole portion 32 of the first circuit body 20A, at each position (five positions) between adjacent contact portions 25 among a plurality (six) of contact portions 25 arranged in the front-rear direction, slit-shaped isolation hole portions 32 penetrating in the thickness direction (up-down direction) of the circuit connection portion 23 are formed so as to extend in the left-right direction (see FIGS. 3 and 5). Thereby, when the bus bar module 10 is flooded with water or the like, it is possible to suppress the occurrence of a problem that conduction (short circuit) occurs between adjacent contact portions 25 due to moisture. Further, two of the five isolation hole portions 32 communicate with two of the hole portions 31, respectively. Thereby, the diameter of the isolation hole portion 32 is enlarged, and the above-described short-circuit suppression effect can be further enhanced.

[0033] The connection operation between the circuit connection portions 23 of the first circuit body 20A and the second circuit body 20B is performed by using a plurality (two) of protrusions 61a (see FIG. 3) provided at a plurality of positions (two positions in this example) on the bottom wall of a circuit body holding portion 61 (see FIG. 3) of a holder 60, which will be described later, corresponding to the plurality of hole portions 31 of the first circuit body 20A and the second circuit body 20B. That is, first, with the circuit connection portion 23 of the first circuit body 20A disposed below the circuit connection portion 23 of the second circuit body 20B, the plurality of protrusions 61a are inserted into 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 in this order from below (see FIG. 4). Thereby, the first circuit body 20A and the second circuit body 20B are accommodated in the holder 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 in the up-down direction.

[0034] Next, a plurality of contact portions 25 of the first circuit body 20A and a plurality of contact portions 25 of the second circuit body 20B are soldered one-to-one independently of each other, and the dummy contact portion 27 of the first circuit body 20A and the dummy contact portion 27 of the second circuit body 20B are soldered. These soldering operations can typically be performed by a method (so-called pulse heat method) in which a paste-like solder is sandwiched between the contact portions 25 and the dummy contact portions 27 arranged to face each other in the vertical direction, and then a heater chip capable of heating the solder to a meltable temperature is pressed against the soldering location and the heater chip is heated for soldering. Note that the soldering can also be performed by a reflow method using a heating furnace. Further, the electrical connection between the circuit connection portions 23 of the first circuit body 20A and the second circuit body 20B may be performed using a conductive adhesive instead of the above-described soldering.

[0035] As a result, at the location where the circuit connection portions 23 of the first circuit body 20A and the second circuit body 20B are connected, a plurality of wiring patterns 26 belonging to the first circuit body 20A and a plurality of wiring patterns 26 belonging to the second circuit body 20B are electrically connected one-to-one independently of each other and are also mechanically integrated. Further, the dummy contact portion 27 of the first circuit body 20A and the dummy contact portion 27 of the second circuit body 20B are mechanically integrated using solder, a conductive adhesive, or the like. Thereby, the first circuit body 20A and the second circuit body 20B can be integrated more firmly.

[0036] In this way, by using the hole portions 31 of the first circuit body 20A, the hole portions 31 of the second circuit body 20B, and the protruding portions 61a of the holder 60, the operation of accommodating the first circuit body 20A and the second circuit body 20B in the holder 60 (circuit body holding portion 61) and the operation of electrically connecting the contact portions 25 (wiring patterns 26) of both while suppressing displacement and the like of the contact portions 25 of both by the protruding portions 61a can be carried out together. Further, when an unintended external force acts on the circuit body 20 after connection (more specifically, the main line portions 21 of the first circuit body 20A and the second circuit body 20B), by receiving the external force with the protruding portions 61a, it is possible to suppress the external force from reaching the connection portion of the contact portions 25 (wiring patterns 26) of both. Therefore, the reliability of the electrical connection between the first circuit body 20A and the second circuit body 20B can be improved.

[0037] Next, the holder 60 will be described. The holder 60 is a resin molded product. As shown in FIG. 1, it integrally includes a pair of left and right strip-shaped circuit body holding portions 61 that extend in the front-rear direction with a space in the left-right direction, and a plurality of connecting portions 62 that connect the pair of left and right circuit body holding portions 61 in the left-right direction at a plurality of locations in the front-rear direction. On the pair of left and right circuit body holding portions 61, a pair of left and right first circuit bodies 20A (main line portion 21 + branch line portion 22) and a second circuit body 20B (main line portion 21 + branch line portion 22) of the circuit body 20 are placed.

[0038] Each of the pair of circuit body holding portions 61 that extend in the front-rear direction is specifically composed of a plurality of divided bodies (not shown) arranged side by side in the front-rear direction and an expansion and contraction portion (not shown) that connects adjacent divided bodies in the front-rear direction. Each expansion and contraction portion has a shape that can be easily expanded and contracted in the front-rear direction by elastic deformation. For this reason, the pair of circuit body holding portions 61 are configured to be expandable and contractible along the front-rear direction. On the bottom wall of each circuit body holding portion 61, as described above, a plurality (two) of protruding portions 61a are provided (see FIG. 3).

[0039] For each of the pair of left and right circuit body holders 61, each of the plurality of divided bodies arranged in the front-rear direction is integrally provided with a bus bar holder 64 (see FIG. 1) adjacent to the outside in the left-right direction. That is, on the outside in the left-right direction of each of the pair of left and right circuit body holders 61, a plurality of bus bar holders 64 are arranged side by side in the front-rear direction. Since each bus bar holder 64 is provided on the corresponding divided body, the interval in the front-rear direction between adjacent bus bar holders 64 in the front-rear direction can be varied by the function of the expansion and contraction part.

[0040] Each bus bar holder 64 houses the corresponding bus bar 40. When the holder 60 is attached to the battery assembly 1, the bus bar 40 housed in each bus bar holder 64 is conductively connected to the corresponding positive electrode 4 and negative electrode 5 adjacent to each other in the front-rear direction on the upper surface of the battery assembly 1.

[0041] Next, the cover 70 will be described. The cover 70, which is a resin molded product, functions to cover the circuit bodies 20 placed on the pair of left and right circuit body holders 61 that are long in the front-rear direction of the holder 60, that is, the first circuit body 20A (main line part 21 + branch line part 22) and the second circuit body 20B (main line part 21 + branch line part 22) (see FIG. 1). For this reason, as shown in FIG. 1, the cover 70 has a strip-like shape extending long in the front-rear direction.

[0042] In the state where the bus bar 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 via a plurality of bus bars 40. Further, each bus bar 40 is conductively connected to an external voltage detection device through 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 in this order. Thereby, the voltage (potential) of each bus bar 40 can be individually detected by an external voltage detection device. Incidentally, if an excessive current exceeding the rated current flows through the electronic component 50 for some reason, the fuse function of the electronic component 50 is exerted, and the electrical connection between the bus bar 40 and the wiring pattern 26 is cut off by the electronic component 50. Thereby, since the inflow of the excessive current into the voltage detection device is prevented, the voltage detection device can be protected.

[0043] In the usage state of the battery assembly 1 to which the bus bar module 10 is attached, each single cell 2 constituting the battery assembly 1 expands and contracts in the stacking direction (front-rear direction) due to the operating heat accompanying charge and discharge, the temperature of the external environment, etc. As a result, the battery assembly 1 also deforms so as to expand and contract in the stacking direction (front-rear direction). Further, due to the assembly tolerance when stacking and arranging the plurality of single cells 2, generally, the size of the battery assembly 1 in the stacking direction (front-rear direction) may differ for each manufactured battery assembly 1 (manufacturing variations may occur).

[0044] In this regard, in the bus bar module 10, even if expansion and contraction in the stacking direction (front-rear direction) of the battery assembly 1 due to thermal deformation of each single cell 2 or manufacturing variations of the battery assembly 1 occur, each of the plurality of expansion and contraction portions of the holder 60 expands and contracts in the front-rear direction, and each branch portion 22 made of a flexible substrate easily bends, so that the expansion and contraction and manufacturing variations due to thermal deformation of the battery assembly 1 can be easily absorbed.

[0045] <Function and Effect> As described above, according to the bus bar module 10 according to the present embodiment, the first circuit body 20A and the second circuit body 20B (main line) composed of flexible substrates are electrically connected to each other at the overlapping portion (circuit connection portions 23) between the main line portions 21 of the first circuit body 20A and the main line portions 21 of the second circuit body 20B, and are integrated. In other words, the first circuit body 20A and the second circuit body 20B are electrically connected. Further, branch line portions 22 (branch lines) extend from the main line portions 21 of the first circuit body 20A and the second circuit body 20B so as to branch. Therefore, when the battery assembly 1 expands and contracts in the stacking direction (front-rear direction) due to thermal deformation of each single battery 2, the branch lines are bent or the like, so that each bus bar 40 can move in the stacking direction of the single battery 2. Similarly, by bending the branch lines or the like, variations in the size of the battery assembly 1 in the stacking direction (front-rear direction) due to the assembly tolerance of the single battery 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 the deformation of the branch lines. Here, in general, even when a flexible substrate contains a large number of circuit structures, it is more easily deformed flexibly with a much smaller force than the electric wire used in the conventional bus bar module described above. Therefore, the assemblability to the battery assembly 1 is improved. Therefore, the bus bar module 10 according to the present embodiment is superior in assemblability to the battery assembly 1 and followability to the deformation and manufacturing variations of the battery assembly 1 as compared with the conventional bus bar module described above.

[0046] Furthermore, according to the bus bar module 10 according to the present embodiment, with respect to 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 single batteries 2, an extension portion of the wiring pattern 26 extends from one contact portion 25 to one side in the crossing direction (left-right direction), and an extension portion of the wiring pattern 26 extends from the other contact portion 25 to the other side in the crossing direction (left-right direction). Thereby, by dispersedly arranging the extension portions of the plurality of wiring patterns 26 extending from the plurality of contact portions 25 in the crossing direction (left-right direction), it is possible to contribute to an improvement in the degree of freedom of the pattern design of the extension portions of the wiring patterns 26 extending from the contact portions 25 and miniaturization of the first circuit body 20A. The same applies to the circuit connection portion 23 of the second circuit body 20B.

[0047] Furthermore, the first circuit body 20A and the second circuit body 20B are prepared as separate bodies and then electrically connected. Therefore, compared with the case where the first circuit body 20A and the second circuit body 20B are formed of a single-piece flexible substrate, the lengths of the first circuit body 20A and the second circuit body 20B in the stacking direction (front-rear direction) are shortened. Therefore, when attaching (i.e., mounting) the electronic component 50 to each branch line portion 22, a dedicated large-scale mounting device is not required. In other words, even when the length and size of the final main line to which the first circuit body 20A and the second circuit body 20B are connected are not suitable for a general (universal) mounting device, after properly mounting the electronic component 50 to the branch line portion 22 using a general (universal) mounting device 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 may be connected, so that the manufacturing cost of the bus bar module 10 can be reduced.

[0048] Furthermore, according to the bus bar module 10 according to the present embodiment, a slit-shaped isolation hole portion 32 is provided between adjacent connection portions of the contact portions 25 of the first circuit body 20A and the second circuit body 20B. Thereby, when the bus bar module 10 is wetted with water or the like, it is possible to suppress the occurrence of a problem that adjacent connection portions are electrically connected (short-circuited) by moisture.

[0049] Furthermore, according to the bus bar module 10 according to the present embodiment, by aligning the hole portion 31 of the first circuit body 20A and the hole portion 31 of the second circuit body 20B so as to overlap (for example, inserting a protrusion 61a or a rod-shaped jig as in this example into the hole portions 31 of the first circuit body 20A and the second circuit body 20B), when electrically connecting (for example, soldering) the wiring patterns 26 of the first circuit body 20A and the second circuit body 20B, misalignment or the like between the two wiring patterns 26 can be suppressed. Therefore, the reliability of the electrical connection between the first circuit body 20A and the second circuit body 20B can be improved. In addition, by communicating the hole portion 31 and the isolation hole portion 32, the diameter of the isolation hole portion 32 is enlarged, and the short-circuit suppression effect described above can be further enhanced.

[0050] Furthermore, according to the bus bar module 10 according to the present embodiment, the holder 60 has a protrusion 61a that is inserted into the hole 31 of the first circuit body 20A and the hole 31 of the second circuit body 20B. Thereby, the operation of accommodating the first circuit body 20A and the second circuit body 20B in the holder 60 and the operation of electrically connecting the wiring patterns 26 of both while regulating the positions of the wiring patterns 26 of both with the protrusion 61a can be performed together. Further, when an unintended external force is applied to the main line (the first circuit body 20A and the second circuit body 20B) after connection, by receiving the external force with the protrusion 61a, it is possible to suppress the external force from reaching the connection portion of the wiring patterns 26 of both. Therefore, the reliability of the electrical connection between the first circuit body 20A and the second circuit body 20B can be improved.

[0051] Furthermore, according to the bus bar module 10 according to the present embodiment, the wiring patterns 26 of the first circuit body 20A and the second circuit body 20B are joined so as to be electrically conductive by a conductive bonding material. Thereby, in addition to electrically connecting the wiring patterns 26 of both, the first circuit body 20A and the second circuit body 20B are also mechanically integrated.

[0052] Furthermore, according to the bus bar module 10 according to the present embodiment, in addition to the joining of the wiring patterns 26 of the first circuit body 20A and the second circuit body 20B, the dummy contact portions 27 of the first circuit body 20A and the second circuit body 20B are joined. Thereby, the first circuit body 20A and the second circuit body 20B can be more firmly integrated.

[0053] <Other aspects> Note that the present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and can be appropriately modified, improved, etc. In addition, the material, shape, dimensions, number, arrangement location, etc. of each component in the above-described embodiments are arbitrary as long as the present invention can be achieved, and are not limited.

[0054] Here, the features of the embodiment of the bus bar module 10 according to the present invention described above are briefly summarized and listed in [1] to [4] below, respectively.

[0055] [1] A bus bar module (10) attached to a battery assembly (1) in which a plurality of single cells (2) are stacked, A first circuit body (20A) composed of a flexible substrate having a first wiring pattern (26), and including a first main line portion (21) arranged to extend along the stacking direction of the plurality of single cells (2), and a first branch line portion (22) extending so as to branch from the first main line portion (21); A second circuit body (20B) composed of a flexible substrate having a second wiring pattern (26), and including a second main line portion (21) arranged to extend along the stacking direction, and a second branch line portion (22) extending so as to branch from the second main line portion (21); A bus bar (40) to be connected to the electrodes (4, 5) of each of the plurality of single cells (2); Electronic components (50) attached to the first branch line portion (22) and the second branch line portion (22) so as to connect the first wiring pattern (26) and the second wiring pattern (26) to the corresponding bus bar (40); A holder (60) that is stretchable along the stacking direction and holds the first circuit body (20A), the second circuit body (20B), and the bus bar (40); The first wiring pattern (26) Has a plurality of first contact portions (25) arranged in the stacking direction and first wiring portions extending from each of the plurality of first contact portions (25), and the first wiring portion extends from one of the first contact portions (25) to one side in the crossing direction crossing the stacking direction, and the first wiring portion extends from the other first contact portion (25) to the other side in the crossing direction, and is configured as such; The second wiring pattern (26) a plurality of second contact portions (25) arranged in the stacking direction, and second wiring portions extending from each of the plurality of second contact portions (25), and 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. In the overlapping portion (23) of the first main line portion (21) and the second main line portion (21), the plurality of first contact portions (25) and the plurality of second contact portions (25) are electrically connected to each other. Bus bar module (10).

[0056] According to the bus bar module having the configuration of [1] above, a first circuit body and a second circuit body (hereinafter also referred to as "main lines") composed of flexible substrates are formed 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 contact portion of the first wiring pattern and the second contact portion of the second wiring pattern are electrically connected to be integrated. In other words, the first circuit body and the second circuit body are electrically connected. Further, first branch portions and second branch portions (hereinafter also referred to as "branch lines") extend so as to branch from the first main line portion and the second main line portion. For this reason, when the battery assembly expands and contracts in the stacking direction due to thermal deformation of each single battery, the branch lines are bent or the like, so that each bus bar can move in the stacking direction of the single battery. Similarly, the branch lines are bent or the like, so that variations in the size of the battery assembly in the stacking direction due to assembly tolerances of the single batteries can be absorbed. In other words, the bus bar module of this configuration can easily cope with expansion and contraction of the battery assembly and manufacturing variations by deforming the branch lines. Here, a flexible substrate is generally more easily deformed flexibly with a much smaller force than an electric wire used in the conventional bus bar module described above, even when it contains a large number of circuit structures. Therefore, the assemblability to the battery assembly is improved. Therefore, the bus bar module of this configuration is superior in assemblability to the battery assembly and followability to deformation and manufacturing variations of the battery assembly compared to the conventional bus bar module described above.

[0057] Furthermore, according to the bus bar module configured as described above, among the plurality of first contact portions arranged in the stacking direction of the plurality of single cells, a first wiring portion extends from one first contact portion to one side in the crossing direction, and a first wiring portion extends from the other first contact portion to the other side in the crossing direction. Thereby, by dispersedly arranging the plurality of first wiring portions extending from the plurality of first contact portions in the crossing direction, it is possible to contribute to an improvement in the degree of freedom of the pattern design of the first wiring portion and a reduction in the size of the first circuit body. 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. Therefore, compared with the case where the first circuit body and the second circuit body are formed of an integral flexible substrate, the lengths of the first circuit body and the second circuit body in the stacking direction are shortened. Therefore, when attaching (i.e., mounting) electronic components to the first branch portion and the second branch portion, a dedicated large mounting device is not required. In other words, even when the length and size of the final main line to which the first circuit body and the second circuit body are connected are not suitable for a general (universal) mounting device, after appropriately mounting electronic components on the branch circuit bodies using a general (universal) mounting device for each of the first circuit body and the second circuit body, the first circuit body and the second circuit body may be connected, so that the manufacturing cost of the bus bar module can be reduced.

[0058] [2] In the bus bar module (10) described in the above [1], the first circuit body (20A) and the second circuit body (20B) have a slit-shaped isolation hole portion (32) penetrating in the thickness direction through the overlapping portion (23) between adjacent connection locations among the plurality of connection locations between the first contact portion (25) and the second contact portion (25). Bus bar module (10).

[0059] According to the bus bar module configured as in the above [2], a slit-shaped isolation hole portion is provided between adjacent connection locations of the first contact portion and the second contact portion. Thereby, it is possible to suppress a problem that adjacent connection locations are electrically connected (short-circuited) by moisture when the bus bar module is exposed to water or the like.

[0060] [3] In the bus bar module (10) described in the above [2], the first circuit body (20A) has a first hole portion (31) penetrating the first circuit body (20A) in the thickness direction, the second circuit body (20B) has a second hole portion (31) penetrating the second circuit body (20B) in the thickness direction, in a state where the first hole portion (31) and the second hole portion (31) are aligned so as to overlap, the first contact portion (25) and the second contact portion (25) are electrically connected, the first hole portion (31), the second hole portion (31), and the isolation hole portion (32) communicate with each other, bus bar module (10).

[0061] According to the bus bar module having the configuration of the above [3], by aligning the first hole portion of the first circuit body and the second hole portion of the second circuit body so as to overlap (for example, inserting a rod-shaped jig into the first hole portion and the second hole portion), during the electrical connection (for example, soldering) between the first wiring pattern and the second wiring pattern, displacement and the like between the two wiring patterns can be suppressed. Further, since at least one of the first hole portion and the second hole portion communicates with the isolation hole portion, the diameter of the isolation hole portion is enlarged, and the above-described short-circuit suppression effect can be further enhanced. Also, the communicated hole portions can be used for alignment.

[0062] [4] In the bus bar module (10) described in the above [3], the holder (60) has a protruding portion (61a) inserted into the first hole portion (31) and the second hole portion (31), bus bar module (10).

[0063] According to the bus bar module configured as described in [4] above, the holder has a protruding portion that is inserted into the first hole portion of the first circuit body and the second hole portion of the second circuit body. As a result, the operation of accommodating the first circuit body and the second circuit body in the holder and the operation of electrically connecting the wiring patterns of both while regulating the positions of the wiring patterns of both with the protruding portion can be performed together. Further, when an unintended external force acts on the main line (the first circuit body and the second circuit body) after connection, by receiving the external force with the protruding portion, it is possible to suppress the external force from acting on the connection portion of the wiring patterns of both. Therefore, the reliability of the electrical connection between the first circuit body and the second circuit body can be improved.

Explanation of Signs

[0064] 1 Battery assembly 2 Single battery 4 Positive electrode (electrode) 5 Negative electrode (electrode) 10 Bus bar module 20A First circuit body 20B Second circuit body 21 Main wire portion (first main wire portion, second main wire portion) 22 Branch wire portion (first branch wire portion, second branch wire portion) 23 Circuit connection portion (overlapping portion) 25 Contact portion (first contact portion, second contact portion) 26 Wiring pattern (first wiring pattern, second wiring pattern) 31 Hole portion (first hole portion, second hole portion) 32 Isolation hole portion 40 Bus bar 50 Electronic component 60 Holder 61a Protruding portion

Claims

1. A bus bar module attached to a battery assembly in which a plurality of single cells are stacked, Composed of a flexible substrate having a first wiring pattern, a first main line portion arranged to extend along the 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, a first circuit body having; Composed of a flexible substrate having a second wiring pattern, a second main line portion arranged to extend along the stacking direction, and a second branch line portion extending so as to branch from the second main line portion, a second circuit body having; A bus bar to be connected to the electrodes of each of the plurality of single cells; Electronic components attached to the first branch line portion and the second branch line portion so as to connect the bus bar corresponding to the first wiring pattern and the second wiring pattern; A holder that is stretchable along the stacking direction and holds the first circuit body, the second circuit body, and the bus bar; and The first wiring pattern is It has a plurality of first contact portions arranged in the stacking direction and first wiring portions extending from each of the plurality of first contact portions, and the first wiring portion extends from one of the first contact portions to one side in the crossing direction intersecting the stacking direction, and the first wiring portion extends from the other first contact portion to the other side in the crossing direction, configured as such; The second wiring pattern is It has a plurality of second contact portions arranged in the stacking direction and second wiring portions extending from each of the plurality of second contact portions, and 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, configured as such; In the overlapping portion of the first main line portion and the second main line portion, the plurality of first contact portions and the plurality of second contact portions are electrically connected to each other. Bus bar module.

2. In the bus bar module according to Claim 1, The first circuit body and the second circuit body are Among the plurality of connection locations between the first contact portion and the second contact portion, having slit-shaped isolation hole portions penetrating the overlapping portion in the thickness direction between adjacent connection locations. Bus bar module.

3. In the bus bar module according to Claim 2, The first circuit body has a first hole portion penetrating the first circuit body in the thickness direction, The second circuit body has a second hole portion penetrating the second circuit body in the thickness direction. With the first hole portion and the second hole portion aligned so as to overlap, the first contact portion and the second contact portion are electrically connected. The first hole portion, the second hole portion, and the isolation hole portion communicate with each other. Bus bar module.

4. In the bus bar module according to claim 3, The holder has a protrusion portion inserted into the first hole portion and the second hole portion. Bus bar module.

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