JP2011210711A - Battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery module miniaturizing a connecting structure of voltage detection wires while reducing the number of components required for connecting the voltage detection wires.SOLUTION: The battery module 10 includes a plurality of connecting members 20 electrically connecting electrode terminals 13A, 13B of adjacent single cells 11, and the voltage detection wires 30 for measuring the voltage of the single cells 11. The voltage detection wire 30 is selected from a flexible flat cable 30 formed by surrounding the outer periphery of a flat conductor 34 into flat shape with insulating resin 33, and a flexible printed board. The connecting members 20 are directly connected to the conductor 34 of the flexible flat cable or to a conductor pattern of the flexible printed board.

Description

  The present invention relates to a battery module.

  In battery modules for electric vehicles and hybrid vehicles, a large number of single cells are connected side by side in order to increase the output. A plurality of unit cells are connected in series or in parallel by connecting electrode terminals of adjacent unit cells with a connecting member such as a bus bar. Here, when a plurality of unit cells are connected in series or in parallel, there is a problem that if the battery characteristics such as the battery voltage are not uniform among the unit cells, the cells are deteriorated or damaged.

  Therefore, in a battery module for a vehicle, a voltage detection line for detecting the voltage of the unit cell is attached to each connection member in order to stop charging and discharging before an abnormality occurs in the voltage between the unit cells. (For example, see Patent Document 1).

Japanese Patent No. 3707595

  In the battery module of Patent Document 1, the voltage detection line is peeled off from the end of the insulation-coated electric wire, and the round terminal is connected to the core wire by caulking, and the round terminal is fitted to the electrode terminal of the unit cell. Thus, a structure in which the electrode terminal is fastened together with a connecting member with a nut is employed (see FIG. 6 of Patent Document 1). Moreover, in this battery module, the connection plate which accommodates a connection member is overlaid on the surface (electrode formation surface) in which the electrode terminal of the cell is formed.

  Therefore, many members are required to connect the voltage detection lines in this battery module. Further, in this battery module, a space for overlapping the connection plate, the connection member, the round terminal and the nut is necessary on the electrode terminal forming surface of the unit cell, so the voltage detection line is connected in the thickness direction of the electrode terminal forming surface. A large space is needed.

  The present invention has been completed based on the above situation, and provides a battery module in which the voltage detection line connection structure is miniaturized while reducing the number of parts required for connection of the voltage detection line. With the goal.

  In order to solve the above problems, the present invention provides a battery module in which a plurality of unit cells having positive and negative electrode terminals are arranged side by side, and electrically connects between the electrode terminals of adjacent unit cells. A plurality of connecting members to be connected, and a voltage detection line for measuring the voltage of the unit cell, wherein the voltage detection line surrounds the outer periphery of a flat conductor with a flat shape with an insulating resin. The connecting member is characterized in that it is directly connected to a conductor of the flexible flat cable or a conductor pattern of the flexible printed board.

  In the present invention, a voltage selected from a flat flexible flat cable (also referred to as FFC) and a flexible printed circuit board (also referred to as FPC) is used as the voltage detection line, and the conductor of the flexible flat cable or the conductive pattern of the flexible printed circuit board is a connecting member. Therefore, the connection structure of the voltage detection line can be a space-saving structure in the thickness direction of the electrode terminal forming surface of the unit cell.

Further, in order to connect the voltage detection line to the single cell, it is sufficient to have one kind selected from a flexible flat cable and a flexible printed circuit board and a connection member, so that the number of parts can be reduced.
As a result, according to the present invention, it is possible to provide a battery module in which the voltage detection line connection structure is miniaturized while reducing the number of components required for connection of the voltage detection line.

The present invention may have the following configurations.
The plurality of connecting members may be integrated by an insulating resin portion formed by heat laminating an insulating resin film. With such a configuration, it is possible to prevent the stress from acting on the connecting portion between the connecting member and the voltage detection line and coming off.

  The voltage detection line may be a flexible flat cable. With such a configuration, the cost can be reduced because the connection member can be connected by a low-cost method such as resistance welding or ultrasonic welding.

A portion of the flexible flat cable that is disposed between the adjacent connecting members may be formed with a folded portion that is formed by folding the flexible flat cable with a fold line that intersects the length direction thereof. .
By the way, when the unit cell constituting the battery module expands in the direction in which the unit cells are arranged and the distance between the electrode terminals is widened, a force to pull in the length direction acts on the flexible flat cable, and the flexible flat cable and the connecting member There is a concern that the connection part with will be disconnected. Therefore, with the above configuration, even if the distance between the electrode terminals is widened due to the expansion of the single cell, the folded portion absorbs the expanded portion, so that the connection portion between the flexible flat cable and the connection member is prevented from coming off. can do.

  The unit cell has a metal battery case, and a resin separator having a protruding portion protruding outward from the outer wall surface of the battery case is disposed between the adjacent unit cells. Good. With such a configuration, it is possible to prevent a short circuit between the electrodes due to the tool, and therefore it is not necessary to provide a short circuit prevention rib separately from the separator. As a result, the number of components can be reduced even in a battery module including a single battery having a metal battery case.

  The voltage detection line is a flexible flat cable in which an outer periphery of a conductor row in which a plurality of conductors are arranged in parallel with each other in an insulated state is surrounded by a flat shape with an insulating resin, and in the flexible flat cable, the plurality of conductors Is connected to one connection member for each of a plurality of adjacent conductors, and separates one circuit from another circuit among a plurality of circuits formed by connecting the plurality of conductors to the connection member. Thus, one circuit may be formed for one connection member.

  The conductor of the flexible flat cable and the connection member may be connected by resistance welding. In such a case, depending on the size of the welding electrode to be used, it may be difficult to connect one conductor to one connection member if the distance between adjacent conductors of the flexible flat cable is small. Therefore, with the configuration as described above, one of the plurality of circuits formed by connecting the conductor and the connection member is connected to one connection member for each of the plurality of adjacent conductors, and another circuit is connected. Since one circuit is formed for each connection member by dividing, a flexible flat cable having a small conductor interval can be used.

  ADVANTAGE OF THE INVENTION According to this invention, the battery module which reduced the connection structure of a voltage detection line can be provided, reducing the number of parts required for the connection of a voltage detection line.

The perspective view of the battery module of Embodiment 1. Top view of battery module Battery module side view Top view of flexible flat cable Top view of connecting member before integration with insulating resin film Top view of connecting member after integration with insulating resin film Top view of connecting member with flexible flat cable connected A perspective view of a connecting member to which a flexible flat cable is connected Partial enlarged view schematically showing the folded part of the flexible flat cable Partial top view of the battery module of Embodiment 2 The perspective view of the 1st accommodation member row Partial top view of the first storage member row Top view of the end receiving member The perspective view of the edge part accommodating member shown in FIG. Top view of first housing member The perspective view of the 1st accommodating member shown in FIG. Partial top view of flexible flat cable Partially enlarged top view of flexible flat cable

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
The battery module 10 of this embodiment is used as a drive source of, for example, an electric vehicle or a hybrid vehicle. As shown in FIG. 1, a plurality of unit cells 11 arranged side by side and a plurality of unit cells are arranged. A plurality of bus bars 20 (connection members 20) for connecting the batteries 11 in series and a voltage detection line 30 for measuring the voltage of each unit cell 11 are provided. Hereinafter, the vertical direction will be described with reference to FIG.

  As shown in FIG. 1, the cell 11 includes a battery case 12 made of metal in which a power generation element (not shown) is housed, and bolt-shaped electrode terminals 13A and 13B (shown as a positive electrode 13A and a negative electrode 13B). Have. Each electrode terminal 13A, 13B protrudes vertically from the upper end surface 12A (terminal forming surface 12A) of the battery case 12. The positive and negative directions of the unit cells 11 are opposite to each other in the unit cells 11 adjacent to each other, whereby the electrode terminals 13A and 13B having different polarities are adjacent to each other. The electrode terminals 13A and 13B are tightened with nuts 14 with the bus bar 20 in between.

  The plurality of unit cells 11 are fixed by two holding plates 18 and 18 arranged on the left side and the right side shown in FIG. 2, and a resin separator 15 is provided between the two adjacent unit cells 11 and 11. Is arranged. As shown in FIG. 3, the separator 15 is provided with a protruding portion 16 that is formed to protrude upward from the terminal forming surface 12 </ b> A of the battery case 12 (outside of the outer wall surface 12 </ b> A of the battery case 12). The protrusion 16 is disposed in a space 23 formed between two adjacent bus bars 20 and 20 and has a function of preventing a short circuit between electrodes due to a tool.

  As shown in FIG. 2, strip-shaped bus bar rows 21 </ b> A and 21 </ b> B formed by connecting a plurality of bus bars 20 are arranged on the plurality of unit cells 11 along the arrangement direction of the unit cells 11. The bus bar rows 21A and 21B are arranged in two rows along the arrangement direction of the single cells 11, and the strip-shaped voltage detection arranged along the arrangement direction of the single cells 11 on each bus bar row 21A and 21B. The line 30 is arranged so as to cover a part thereof (see FIGS. 3, 7, and 8).

  As shown in FIGS. 3 and 6, the bus bar rows 21A and 21B have polypropylene (PP), polyvinyl chloride (PVC), polybutylene terephthalate (PBT), polyethylene terephthalate so as to border two sides in the longitudinal direction. An insulating resin portion 22A formed by heat laminating a film made of an insulating resin such as (PET) is provided. That is, the bus bar rows 21A and 21B are obtained by connecting and integrating a plurality of bus bars 20 with the insulating resin portion 22A.

  As shown in FIG. 3, the plurality of bus bars 20 constituting the bus bar rows 21A and 21B are arranged with a predetermined interval X between the adjacent bus bars 20 and 20, and the interval X and the two-hole bus bar are arranged. 20A (details will be described later) is set to be slightly larger than the dimension in the width direction of the two unit cells 11 and 11 with the separator 15 interposed therebetween. Yes.

  The plurality of bus bars 20 constituting the bus bar rows 21A and 21B are arranged so that the terminal insertion holes 24 through which the electrode terminals 13A and 13B are inserted and connected are arranged in a row. Among the two bus bar rows 21A and 21B, in the front bus bar row 21A shown in FIG. 2, a single-hole bus bar 20B having one terminal insertion hole 24 is disposed at both ends, and is disposed at both ends. Between the two one-hole bus bars 20B, 20B, four two-hole bus bars 20A in which two terminal insertion holes 24 are formed are arranged. Of the two bus bar rows 21A and 21B, in the rear bus bar row 21B shown in FIG. 2, five two-hole bus bars 20A are arranged. In this specification, “bus bar 20” includes a two-hole bus bar 20A and a one-hole bus bar 20B.

  As shown in FIG. 5, each bus bar 20 has a substantially rectangular shape, and is formed with terminal insertion holes 24, 24 through which the electrode terminals 13A, 13B are inserted and connected. The bus bar 20 can be formed by punching a metal plate material such as copper, copper alloy, aluminum, aluminum alloy, gold, and stainless steel (SUS). The bus bar 20 may be plated (Sn, Ni, Ag, Au) in order to improve weldability.

  Insulation resin portions 22B formed by thermally laminating films made of an insulation resin such as PP, PVC, PBT, and PET are provided on a part of the short side of the bus bar 20, respectively. The portion of the bus bar 20 where the short side insulating resin portion 22B is provided corresponds to the end portion of the terminal connection region 25 for connection to the electrode terminals 13A and 13B, and each bus bar is provided with the insulating resin portion 22B. Between 20 is maintained in an insulated state. A space 23 formed between the end portions of the terminal connection regions 25 of the adjacent bus bars 20 and 20 is a protruding portion arrangement space 23 in which the protruding portion 16 of the separator 15 is arranged.

  The plurality of bus bars 20 are connected to the electrode terminals 13A and 13B adjacent to each other (electrically) and to a voltage detection line 30 for measuring the voltage of the unit cell 11.

  In the present embodiment, a flexible flat cable (FFC 30) formed by surrounding the outer periphery of a flat conductor 34 having a flat shape in a flat shape with an insulating resin 33 is used as the voltage detection line 30 connected to each bus bar 20.

  As the FFC 30, for example, a conductor row formed by paralleling a plurality of copper foils (conductors 34) in an insulated state and laminated with an insulating resin such as polyethylene terephthalate can be used. The thickness of the FFC 30 is preferably 0.6 mm or greater and 0.7 mm or less.

  As shown in FIG. 1, the FFCs 30 are arranged one by one on the two bus bar rows 21 </ b> A and 21 </ b> B, and are folded into a trapezoidal shape on the rightmost holding plate 18, and are placed on the unit cells 11. It is connected to the arranged battery ECU 17. The battery ECU 17 is equipped with a microcomputer, elements, and the like, and has a function for detecting voltage, current, temperature, etc. of the unit cells 11 and controlling charge / discharge of each unit cell 11. Of the configuration.

  As shown in FIG. 1, a single mountain fold portion 31 (folding portion 31) is formed in a portion of the FFC 30 that is disposed between adjacent bus bars 20 and 20. The mountain fold portion 31 can be formed by folding at a fold line 31 </ b> A in a direction (crossing direction) substantially perpendicular to the length direction of the FFC 30. The projecting dimension Z of the mountain fold 31 is preferably 10 mm or less (see FIG. 9).

  The FFC 30 is provided with a connection portion 32 with each bus bar 20. Specifically, the plurality of conductors 34 constituting the FFC 30 are connected to one bus bar 20 one by one. The connection portion 32 between the FFC 30 and the bus bar 20 is formed by peeling the insulating resin 33 of the FFC 30 with a laser or the like to expose the conductor 34, and the exposed conductor 34 and the bus bar 20 are connected by resistance welding, ultrasonic welding, soldering, or the like. It can form by connecting by various welding methods, such as attachment. Of these welding methods, resistance welding is preferred because of its low cost.

Next, a method for attaching the bus bar 20 and the voltage detection line 30 will be described.
The insulating resin 33 of the FFC 30 is peeled off by a laser (not shown) to expose the conductor 34 corresponding to each bus bar 20. Next, a predetermined portion of the FFC 30 is bent at a fold line 31A in a direction substantially perpendicular to the length direction of the FFC 30 to form a single mountain fold 31, and an end connected to the ECU 17 of the FFC 30 is bent into a trapezoid ( (See FIG. 4).

  At the same time as or before or after the processing of the FFC 30, the bus bar rows 21A and 21B are manufactured by the following procedure. First, the bus bar 20 is formed by punching a metal plate material. In the present embodiment, two 1-hole bus bars 20B and nine 2-hole bus bars 20A are formed. These molded bus bars 20 are plated as necessary.

  Next, five two-hole bus bars 20A are arranged so that the terminal insertion holes 24 are arranged in a line at intervals, two one-hole bus bars 20B, and these one-hole bus bars A bus bar 20 </ b> A having four two holes arranged therebetween is prepared (see FIG. 5) with an interval so that the terminal insertion holes 24 are arranged in a row.

  Next, a part of the short side of each bus bar 20 (the end of the terminal connection region 25) is sandwiched between insulating resin films, and thermal lamination is performed. Next, a thermal laminating process is performed by sandwiching the longitudinal sides of each bus bar 20 between insulating resin films. By thermally laminating the insulating resin film, insulating resin portions 22A and 22B are provided on two sides of the bus bar 20 in the longitudinal direction and a part of the short side of each bus bar, respectively (see FIG. 6). ). Since the insulating resin portions 22A provided on the longitudinal sides of the bus bar 20 are continuously formed so as to connect adjacent bus bars, the plurality of bus bars 20 are integrated by the insulating resin portions 22A. Note that an adhesive may be used as necessary during the thermal lamination.

  The bus bar rows 21A and 21B to which the FFC 30 is connected are obtained by placing the FFC 30 on the bus bar rows 21A and 21B produced by the above procedure and connecting the exposed conductors 34 of the FFC 30 and the bus bars 20 by welding. Is obtained (see FIGS. 7 and 8).

  Next, 10 unit cells 11 are arranged side by side so that electrode terminals 13A and 13B having opposite poles are arranged between two adjacent unit cells 11 and 11, and the upper surface 12A (terminals) of these unit cells 11 is arranged. The bus bar rows 21A and 21B connected to the FFC 30 produced by the above-described procedure are placed on the formation surface 12A).

  Next, as shown in FIG. 1, all the electrode terminals 13 </ b> A and 13 </ b> B of the plurality of unit cells 11 arranged side by side are inserted into all the terminal insertion holes 24 of the bus bar 20. Next, as shown in FIG. 1, the nut 14 is screwed into the electrode terminals 13 </ b> A and 13 </ b> B protruding from the terminal insertion hole 24 and tightened. When the nuts 14 are tightened on all the electrode terminals 13A and 13B, the battery module 10 to which the bus bar 20 and the voltage detection line 30 are attached is completed.

According to the structure of the said embodiment, there exist the following effects.
According to the present embodiment, since the flat FFC 30 is used as the voltage detection line 30 and the conductor 34 of the FFC 30 is directly connected to the bus bar 20, the connection structure of the voltage detection line 30 is changed in the vertical direction (terminal formation) of the unit cell 11. A space-saving structure can be obtained in the thickness direction of the surface 12A (see FIG. 3).

In the present embodiment, the FFC 30 (voltage detection line 30) and the bus bar 20 are sufficient to connect the voltage detection line 30 to the unit cell 11, so the number of parts can be reduced.
As a result, according to the present embodiment, it is possible to provide the battery module 10 in which the connection structure of the voltage detection line 30 is downsized while reducing the number of components required for the connection of the voltage detection line 30.

  Further, according to the present embodiment, since the plurality of bus bars 20 are integrated by the insulating resin portion 22A formed by heat laminating the insulating resin film, stress is applied to the connection portion 32 between the bus bar 20 and the voltage detection line 30. Can be prevented from coming off due to the action.

  In addition, according to the present embodiment, since the FFC 30 is used as the voltage detection line 30, it can be connected to the bus bar 20 by a low-cost method such as resistance welding or ultrasonic welding, so that the cost can be reduced.

  By the way, when the unit cell 11 constituting the battery module 10 expands in the direction in which the unit cells 11 are aligned, when the distance between the electrode terminals 13A and 13B is widened, a force pulling in the length direction acts on the FFC 30, and the FFC 30 There is a concern that the connecting portion 32 with the bus bar 20 may come off. However, in this embodiment, a mountain fold portion 31 formed by folding the FFC 30 with a fold line 31A in a direction intersecting the length direction is formed in the portion of the FFC 30 disposed between the adjacent bus bars 20, 20. Therefore, even if the space between the electrode terminals 13A and 13B is widened due to the expansion of the unit cell 11, the expanded portion 31 absorbs the expanded portion, so that the connection portion 32 between the FFC 30 and the bus bar 20 is prevented from being disconnected. Can do.

  Furthermore, according to the present embodiment, the unit cell 11 has the metal battery case 12, and the protruding portion 16 that protrudes outward from the upper surface 12 </ b> A of the battery case 12 between the adjacent unit cells 11 and 11. Since the resin-made separator 15 which has this is arrange | positioned, since the short circuit between the electrodes by a tool can be prevented, it is not necessary to provide a short-circuit prevention rib separately from the separator 15. As a result, the number of components can be reduced also in the battery module 10 including the single battery 11 having the metal battery case 12.

<Embodiment 2>
A second embodiment of the present invention will be described with reference to FIGS.
The battery module 50 of the present embodiment is used as a drive source of an electric vehicle or a hybrid vehicle, for example. As shown in FIG. 10, a plurality of unit cells 51 arranged side by side and a plurality of unit cells A plurality of bus bars 60 (connection members 60) that connect the batteries 51 in series; a plurality of housing members 70 that house the bus bars 60 and house and hold the voltage detection wires 84 that measure the voltage of each unit cell 51; Is provided. Hereinafter, the vertical direction will be described with reference to FIG.

  As shown in FIG. 10, the unit cell 51 includes a resin battery case 52 in which a power generation element (not shown) is housed, and bolt-shaped electrode terminals 53 </ b> A and 53 </ b> B (shown as a positive electrode 53 </ b> A and a negative electrode 53 </ b> B). Have. Each electrode terminal 53A, 53B protrudes vertically from the upper end surface 52A (terminal formation surface 52A) of the battery case 52. The positive and negative directions of the unit cells 51 are opposite to each other in the unit cells 51 adjacent to each other, whereby the electrode terminals 53A and 53B having different polarities are adjacent to each other. The electrode terminals 53 </ b> A and 53 </ b> B are tightened with nuts 54 with the bus bar 60 accommodated in the accommodating member 70 interposed therebetween. Although not shown in detail, the plurality of single cells 51 are fixed by two holding plates as in the first embodiment.

  As shown in FIG. 10, a plurality of housing members 70 are arranged along the arrangement direction of the single cells 51 on the unit cell row 50 </ b> A including the plurality of single cells 51, thereby forming a belt-like housing member as a whole. Rows 71A and 71B are arranged. The housing member rows 71A and 71B are arranged in two rows along the arrangement direction of the cells 51, and each of the housing member rows 71A and 71B accommodates the bus bar 60 and is arranged along the arrangement direction of the cells 51. A strip-shaped voltage detection line 84 is held (see FIGS. 10 and 11). Here, the accommodation member row 71A arranged on the front side in FIG. 10 is referred to as a first accommodation member row 71A, and the accommodation member row 71B arranged on the back side in FIG. 10 is referred to as a second accommodation member row 71B. .

  As shown in FIG. 11, the first housing member row 71 </ b> A includes 11 (plural) housing members 70. The eleven accommodating members 70 constituting the first accommodating member row 71A are not connected to each other, but are connected together by attaching the FFC 84 used as the voltage detection line 84 to the accommodating member. The FFC 84 is connected to a battery ECU (not shown) like the FFC 84 of the first embodiment.

  Although the details are not shown, the second housing member row 71B is composed of 12 (plural) housing members 70. The twelve accommodation members 70 constituting the second accommodation member row 71B are not connected to each other, but are connected and collectively by the FFC 84.

  Of the eleven accommodating members 70 constituting the first accommodating member row 71A, the accommodating members 70B (referred to as “end accommodating members 70B”) respectively disposed at the left and right end portions shown in FIG. The size of the accommodation member 70A (referred to as “first accommodation member 70A”) to be arranged is approximately 1.5 times larger. The twelve housing members constituting the second housing member row 71B have the same shape and size as the first housing member 70A, and these are also referred to as the first housing member 70A. In the present embodiment, the first housing member 70 </ b> A and the end housing member 70 </ b> B are used as the housing member 70 when not distinguished from each other.

  The end accommodating member 70B is made of synthetic resin, and is placed so as to straddle the three adjacent unit cells 51. As shown in FIG. 13, the two accommodating portions of the two bus bars 60A and 60B are accommodated. Sections 72 and 74, and an FFC housing section 75 that houses an FFC 84 for measuring the voltage of the unit cell 51. The two bus bar accommodating portions 72 and 74 and the FFC accommodating portion 75 are formed by integrally molding synthetic resin.

  As shown in FIG. 11, the two end accommodating members 70B have a symmetric shape, and both accommodate a one-hole bus bar 60B (details will be described later) on the end side of the unit cell row 50A. 1 bus bar accommodating portion 72, and a second bus bar accommodating portion 74 for accommodating a two-hole bus bar 60 </ b> A (details will be described later) on the center side of the cell array 50 </ b> A. In the present embodiment, the 1-hole bus bar 60B and the 2-hole bus bar 60A are collectively referred to as the bus bar 60.

  The dimension in the longitudinal direction of the end accommodating member 70B is slightly smaller than the dimension in the width direction of the three unit cells 51. Thus, when the end accommodating member 70B is arranged in the unit cell row 50A, it is adjacent. A slight gap is formed between the first housing member 70A (see FIG. 10).

  As shown in FIG. 12, the end accommodating member 70B has two types of bus bars: a one-hole bus bar 60B in which one terminal insertion hole 64 is formed and a two-hole bus bar 60A in which two terminal insertion holes 64 are formed. 60A and 60B are accommodated. Both the 1-hole bus bar 60B and the 2-hole bus bar 60A are substantially T-shaped. The bus bar 60 is made of a metal such as copper, a copper alloy, or stainless steel (SUS). A wide portion of the bus bar 60 is a region 65 in which the terminal insertion hole 64 is formed, that is, a terminal connection region 65 that is electrically connected to the electrode terminals 53A and 53B of the unit cell 51. A region 66 formed to be narrower than that is a detection line connection region 66 connected to the FFC 84. Of the corners of the terminal connection region 65 of the bus bar 60, two corners arranged along the back walls 72A and 74A (the back side in FIG. 12) of the bus bar housing portions 72 and 74 are cut out in a substantially triangular shape. ing.

  As shown in FIGS. 10 and 11, the bus bar accommodating portions 72 and 74 of the end accommodating member 70B are arranged at the end of the unit cell row 50A, and the first bus bar accommodating portion 72 in which the one-hole bus bar 60B is accommodated. And a second bus bar accommodating portion 74 that is disposed so as to straddle the two unit cells 51 and accommodates the two-hole bus bar 60A.

  As shown in FIG. 12, the first bus bar accommodating portion 72 can accommodate the terminal connection region 65 of the one-hole bus bar 60B in which one terminal insertion hole 64 is formed. Side walls 72A, 72B, 72D, and 72E that are cut off from the terminal formation surface 52A of the unit cell 51 are formed in the first bus bar accommodating portion 72 so as to surround the terminal connection region 65 of the one-hole bus bar 60B (see FIG. 13 and FIG. 14). Of the side walls 72A, 72B, 72D, 72E of the first bus bar housing part 72, a part of the side wall 72B on the FFC housing part 75 side (referred to as the front side wall and the front wall 72B in FIG. 13) is open.

  The bottom wall of the first bus bar accommodating portion 72 (the wall portion on the side where the cell 51 is placed on the terminal forming surface 52A) is the left and right side walls 72D and 72E (referred to as the left side wall 72D and the right side wall 72E) shown in FIG. A portion other than the mounting portion 73A on which the end portion of the terminal connection region 65 of the one-hole bus bar 60B formed along the center can be cut out in a substantially rectangular shape.

  In the right side wall 72E of the first bus bar accommodating portion 72, slits 73B extending upward from the lower end of the right side wall 72E are formed at the end on the opening 72C side and at a position adjacent to the placement portion 73A, respectively. Between the two slits 73B, 73B, a locking claw 73C is provided on the upper surface of the one-hole bus bar 60B to lock the one-hole bus bar 60B. Similarly to the right side wall 72E, two slits 73B and 73B and a locking claw 73C are also provided on the left side wall 72D of the first bus bar accommodating portion 72.

  The second bus bar accommodating portion 74 can accommodate the terminal connection area 65 of the two-hole bus bar 60A in which two terminal insertion holes 64 are formed. Side walls 74A, 74B, 74D, and 74E are formed in the second bus bar accommodating portion 74 so as to surround the terminal connection area 65 of the two-hole bus bar 60A (see FIG. 5). 13 and FIG. 14). Of the side walls 74A, 74B, 74D, and 74E of the second bus bar housing portion 74, a part of the side wall 74B on the FFC housing portion 75 side (referred to as the front side wall and the front wall 74B in FIG. 13) is open. The left end of the front wall 74B in FIG. 13 is connected to the front wall 72B of the first bus bar accommodating portion 72.

  The bottom wall of the second bus bar housing portion 74 (the wall portion on the side where the cell 51 is placed on the terminal forming surface 52A) is the left and right side walls 74D and 74E (referred to as the left side wall 74D and the right side wall 74E) shown in FIG. The end portion mounting portion 74F on which the end portion of the terminal connection area 65 of the 2-hole bus bar 60A formed along the center can be placed, and the center where the substantially central portion of the terminal connection area 65 of the 2-hole bus bar 60A is placed. Parts other than the mounting portion 74G are cut away.

  Two slits 74H and 74H extending upward from the lower end of the rear wall 74A of the second bus bar accommodating portion 74 are formed, and two holes are provided between the two slits 74H and 74H. A locking claw 74J is provided on the upper surface of the bus bar 60A to lock the two-hole bus bar 60A. In the 2nd bus-bar accommodating part 74, the latching claw 74J is formed in the position corresponding to the center mounting part 74G.

  The FFC accommodating portion 75 covers the substantially rectangular FFC placement portion 76 on which the detection line connection region 66 and the FFC 84 of each bus bar 60 are placed, and the FFC 84 placed on the FFC placement portion 76. A substantially rectangular FFC holding portion 78 arranged and held, and a hinge 77 that connects the FFC placement portion 76 and the FFC holding portion 78 are provided. The FFC placement unit 76 and the FFC holding unit 78 are formed substantially in parallel.

  The FFC placement portion 76 includes a first cutout portion 76 </ b> A that is continuous from the cutout portion of the bottom wall of the first busbar housing portion 72 and is cut out in a T shape as a whole, and a region along the second busbar housing portion 74. A second cutout portion 76B cut out in a T-shape is formed at substantially the center.

  A first locking protrusion 76C that locks the detection line connection region 66 of the one-hole bus bar 60B is provided at an edge along the first cutout portion 76A of the FFC mounting portion 76, and the FFC mounting portion 76 is provided. A second locking projection 76D that locks the detection line connection region 66 of the two-hole bus bar 60A is provided at the edge along the second notch 76B. In addition, the FFC placement portion 76 is provided with two types of bus bar placement portions 76E and 76F that are recessed from other portions so that the two-hole bus bar 60A and the one-hole bus bar 60B can be fitted thereinto. In the FFC placement section 76, the bus bar placement section 76E in which the 1-hole bus bar 60B can be fitted is the first bus bar placement section 76E, and the bus bar placement section 76F in which the 2-hole bus bar 60A can be fitted is the second bus bar placement. This is part 76F.

  A total of four FFC fixing protrusions 76G for fixing the FFC 84 are formed on both end portions in the longitudinal direction of the FFC placement portion 76 in a protruding manner.

  On the surface of the FFC holding portion 78 that contacts the FFC 84 (the upper surface in FIG. 14), four FFC fixings that can fit the four FFC fixing protrusions 76G formed on the FFC mounting portion 76, respectively. The holes 78A are formed at the corners, and a plurality of ribs 78B extending along the longitudinal direction of the FFC holding part 78 are formed. Further, the FFC holding portion 78 has a relief recess 78C for escaping the first locking projection 76C and the second locking projection 76D formed on the FFC mounting portion 76 when being superimposed on the FFC mounting portion 76. 78D is formed.

Next, the first housing member 70A will be described. The first housing member 70A is made of synthetic resin and is placed so as to straddle two adjacent unit cells 51. As shown in FIG. 15, the bus bar housing unit 79 and the voltage for measuring the unit cells 51 are measured. And an FFC accommodating portion 80 that accommodates the FFC 84. The bus bar housing portion 79 and the FFC housing portion 80 are formed by integrally molding synthetic resin.
The dimension in the longitudinal direction of the first housing member 70A is slightly smaller than the dimension in the width direction of the two unit cells 51, so that a slight gap is formed between the adjacent first housing member 70A. It is like that.

  As shown in FIG. 12, the first housing member 70A accommodates a two-hole bus bar 60A in which two terminal insertion holes 64 are formed. Since the two-hole bus bar 60A accommodated in the first accommodating member 70A has the same configuration as the two-hole bus bar 60A accommodated in the end accommodating member 70B, detailed description thereof is omitted.

  The bus bar accommodating portion 79 of the first accommodating member 70A is arranged so as to straddle the two unit cells 51, as shown in FIGS. Side walls 79A, 79B, 79D, 79E are formed in the bus bar accommodating portion 79 so as to surround the terminal connection area 65 of the two-hole bus bar 60A (see FIG. 15 and FIG. 15). See FIG. Of the side walls 79A, 79B, 79D, and 79E of the bus bar housing part 79, a part of the side wall 79B on the FFC housing part 80 side (referred to as the front side wall and the front wall 79B in FIG. 15) is open.

  The bottom wall of the bus bar housing part of the first housing member 70A (the wall part on the side placed on the terminal forming surface 52A of the unit cell 51) has left and right side walls 79D and 79E (left side wall 79D and right side wall shown in FIG. 15). 79E), the end mounting portion 79F on which the end of the terminal connection region 65 of the two-hole bus bar 60A can be mounted, and the substantially central portion of the terminal connection region 65 of the two-hole bus bar 60A is mounted. A portion other than the central mounting portion 79G to be formed is cut out.

  As shown in FIG. 16, two slits 79 </ b> H and 79 </ b> H extending upward from the lower end of the rear wall 79 </ b> A of the bus bar housing portion 79 of the first housing member 70 </ b> A are formed. Between the slits 79H and 79H, there is provided a locking claw 79J that is disposed on the upper surface of the 2-hole bus bar 60A and locks the 2-hole bus bar 60A. In the bus bar accommodating portion 79, the locking claw 79J is formed at a position corresponding to the central placement portion 79G.

  The FFC accommodation portion 80 of the first accommodation member 70A is placed on the FFC placement portion 81 and the substantially rectangular FFC placement portion 81 on which the detection line connection region 66 and the FFC 84 of the two-hole bus bar 60A are placed. A substantially rectangular FFC holding part 83 arranged and held so as to cover the FFC 84, and a hinge 82 connecting the FFC placement part 81 and the FFC holding part. The FFC placement unit 81 and the FFC holding unit 83 are formed substantially in parallel.

  The FFC placement portion 81 of the first housing member 70 </ b> A is formed with a third cutout portion 81 </ b> A that is cut out in a T shape in the approximate center of the area along the busbar housing portion 79.

  A third locking projection 81C that locks the detection line connection region 66 of the two-hole bus bar 60A is provided at an edge along the third notch 81A of the FFC placement portion 81 of the first housing member 70A. . Further, the FFC placement portion 81 is provided with a third bus bar placement portion 81E that is recessed from other portions so that the two-hole bus bar 60A can be fitted.

  Similarly to the end accommodating member 70B, two FFC fixing protrusions 81F for fixing the FFC 84 are protruded from each other at both ends in the longitudinal direction of the FFC placement portion 81 of the first accommodating member 70A. .

  The four FFC fixing protrusions 81F formed on the FFC placement portion 81 can be respectively fitted on the surface (the upper surface in FIG. 16) of the first housing member 70A that is in contact with the FFC 84 of the FFC holding portion 83. Four FFC fixing holes 83A are formed at the corners, and a plurality of ribs 83B extending along the longitudinal direction of the FFC holding portion 83 are formed. In addition, the FFC holding part 83 is formed with a relief recess 83C that allows the third locking projection 81C formed on the FFC placement part 81 to escape when being superimposed on the FFC placement part 81.

  Now, as shown in FIG. 12, the FFC 84 accommodated in the FFC accommodating portion 75 of the end accommodating member 70B and the FFC accommodating portion 80 of the first accommodating member 70A are arranged in the arrangement direction of the cells 51 (the horizontal direction in FIG. 10). It is arranged to extend. As shown in FIG. 10, the FFC 84 is disposed on each of the first housing member row 71A and the second housing member row 71B.

  As the FFC 84, for example, a conductor row formed by paralleling a plurality of copper conductors 85 in an insulated state and laminated with an insulating resin 86 such as polyethylene terephthalate can be used. As shown in FIGS. 17 and 18, a plurality of mounting holes 89 are formed in the edge portion along the longitudinal direction of the FFC 84 so as to be inserted into the FFC fixing projections 76G and 81F formed in the FFC placement portions 76 and 81. ing.

  The FFC 84 is provided with a connection portion 86 with each bus bar 60. In the present embodiment, seven (a plurality of) conductors 85 constituting the FFC 84 are connected to each bus bar 60 for every two adjacent conductors 85. The connecting portion 86 between the FFC 84 and the bus bar 60 can be formed by the method exemplified in the first embodiment. Specifically, among the plurality of conductors 85 constituting the FFC 84, the conductor 85a disposed on the uppermost side in FIG. 18 is connected to the bus bar 60 together with the adjacent conductor 85b (second conductor 85b from the top), and from above. The second conductor 85b is connected to the bus bar 60 together with the adjacent conductor 85c (third conductor 85c from the top), and the third conductor 85c from the top is connected to the bus bar 60 together with the adjacent conductor 85d (fourth conductor 85d from the top). The fourth conductor 85d from the top is connected to the bus bar 60 together with the adjacent conductor 85e (the fifth conductor 85e from the top), and the fifth conductor 85e from the top is connected to the adjacent conductor 85f (the sixth conductor from the top). The conductor 85f) is connected to the bus bar 60 and the sixth conductor 85f from the top is adjacent to the conductor 85g (seventh conductor 85g from the top). Both are connected to the bus bar 60. When two adjacent conductors 85 and the bus bar 60 are connected in this way, two circuits are formed. One of the two circuits is separated from the other circuit by the dividing portion 88. Yes. In addition, since the seventh conductor 85g from the top is connected to the bus bar 60 alone, the dividing portion is not formed.

  As shown in FIG. 18, the two circuits formed by connecting the top conductor 85a and the second conductor 85b from the top to the bus bar 60 are divided portions 88 provided in the second conductor 85b. Therefore, one circuit is formed for one bus bar 60. The same applies to the other conductors 85. The dividing portion 88 is arranged between the adjacent bus bars 60 as shown in FIGS. 10 and 12.

The FFC 84 used in the present embodiment can be provided with up to seven connection portions 86 with the bus bar 60. Therefore, when the number of bus bars 60 connected to the FFC 84 is eight or more, the FFC 84 and each bus bar 60 are connected using two or more FFCs 84. In the present embodiment, since the total number of bus bars 60 accommodated in the first accommodating member row 71A is 13, FFC 84 (84A) shown in FIG. 17 is the eighth from the right to the thirteenth from the right (the left end) in FIG. The FFC 84 (84B) shown in FIG. 18 is connected to the first through seventh bus bars from the right to the seventh bus bar in FIG. 11, and the FFC 84A placed first is connected to the bus bar. Arrange them so that they overlap.
Although the details of the arrangement procedure of the FFC 84 in the second housing member row 71B are not shown, they are the same as the placement procedure in the first housing member row 71A. Since the total number of bus bars 60 accommodated in the second accommodating member row 71B is 12, the FFC 84 and each bus bar 60 are connected by using two FFCs 84A shown in FIG.

Next, a method for assembling the battery module 50 of the present embodiment will be briefly described. In the present embodiment, a case will be described in which 24 unit cells 51 are connected in series in one row.
Twenty-four unit cells 51 are arranged side by side with the terminal formation surface 52A on the upper side to produce a unit cell array 50A. Two end accommodating members 70B and 21 first accommodating members 70A are prepared. As the two end accommodating members 70B, one set having a symmetrical shape is prepared (see FIG. 11).

  The FFC 84 to be arranged in the first housing member row 71A and the second housing member row 71B is prepared. Specifically, the insulating resin 86 of the FFC 84 is peeled off by a laser (not shown) to expose two adjacent conductors 85 corresponding to each bus bar 60, and a dividing portion 88 is formed on one of the exposed conductors 85. (See FIG. 17 and FIG. 18). The dividing portion 88 is generated by punching a part of the target conductor 85 with a punch or the like.

One-hole bus bar 60B and two-hole bus bar 60A are accommodated one by one in end portion accommodating member 70B, and two-hole bus bar 60A is accommodated in first accommodating member 70A.
The detection line connection area 66 of the 1-hole bus bar 60B is arranged in the first bus bar mounting part 76E, and the terminal connection area 65 of the 1-hole bus bar 60B is arranged in the first bus bar accommodation part 72 to perform the accommodation operation. By mounting the detection line connection region 66 of the 1-hole bus bar 60B on the bus bar mounting portion 76E, the 1-hole bus bar 60B is locked by the first locking protrusion 76C. When the terminal connection area 65 of the 1-hole bus bar 60B is inserted into the first bus bar housing portion 72, the end of the 1-hole bus bar 60B comes into contact with the two locking claws 73C and 73C so that the locking claws 73C and 73C are moved outward. When the end portion of the one-hole bus bar 60B is placed on the placement portions 73A and 73A formed on the right side wall 72E and the left side wall 72D of the first bus bar accommodating portion 72, the two locking claws 73C and 73C are provided. Is elastically restored, and the terminal connection region 65 of the one-hole bus bar 60B is locked to the first bus bar accommodating portion 72 in the accommodated state.

  The 2-hole bus bar 60A is accommodated in the same manner as the 1-hole bus bar 60B. In the end accommodating member 70B, the detection line connection region 66 of the two-hole bus bar 60A is locked by the second locking protrusion 76D, and the terminal connection region 65 of the two-hole bus bar 60A is the locking claw of the second bus bar receiving portion 74. It is locked by 74J. In the first housing member 70A, the detection line connection region 66 of the 2-hole bus bar 60A is locked by the third locking protrusion 81C, and the terminal connection region 65 of the 2-hole bus bar 60A is locked by the locking claw 79J of the bus bar housing portion 79. Locked.

Next, the first housing member row 71A and the second housing member row 71B are produced.
When the two end accommodating members 70B and the nine first accommodating members 70A are arranged at intervals so that the terminal insertion holes 64 are aligned in a row, the FFC placement portions 76 and 81 of the eleven accommodating members 70A and 70B are formed. Line up in a row. By inserting the FFC fixing protrusions 76G and 81F of the FFC mounting portions 76 and 81 arranged in a line into the mounting holes 89 of the FFC 84, the FFC 84 is fixed to the FFC mounting portions 76 and 81, and the bus bars 60 and the FFC 84 are fixed. And connect. When connecting each bus bar 60 and the FFC 84, two adjacent conductors 85 (for example, conductors 85a and 85b) in an exposed state are connected to each other by welding to the corresponding bus bar 60.

  Next, when the FFC fixing holes 78A and 83A of the FFC holding portions 78 and 83 are inserted into the FFC fixing protrusions 76G and 81F of the FFC placement portions 76 and 81 to cover the FFC 84, the FFC 84 is in a holding state, and the first housing member Column 71A is obtained.

  Similarly, when the twelve first housing members 70A are arranged at intervals such that the terminal insertion holes 64 are arranged in one row, the FFC placement portions 81 of the twelve housing members 70A are arranged in a row. By inserting the FFC fixing protrusions 81F of the FFC mounting portions 81 arranged in a line into the mounting holes 89 of the FFC 84, the FFC 84 is fixed to the FFC mounting portion 81, and the bus bars 60 and the FFC 84 are connected by the method described above. Connect in the same way. Next, when the FFC fixing hole 83A of the FFC holding portion 83 is inserted into the FFC fixing protrusion 81F of the FFC placement portion 81 to cover the FFC 84, the FFC 84 is in a holding state, and the second housing member row 71B is obtained.

  The first housing member row 71A and the second housing member row 71B produced by the procedure as described above are respectively arranged at predetermined positions on the terminal formation surface 52A of the unit cell row 50A. By inserting the electrode terminals 53A and 53B of the unit cell 51 into the terminal insertion holes 64 of the bus bars 60 housed in the housing members 70A and 70B, and screwing and tightening the nuts 54 to the electrode terminals 53A and 53B, respectively. The electrode terminals 53A and 53B and the bus bar 60 are connected. When this connection work is completed, the battery module 50 of this embodiment is obtained.

According to the structure of this embodiment, there exist the following effects.
Also in the present embodiment, as in the first embodiment, the flat FFC 84 is used as the voltage detection line 84, and the conductor 85 of the FFC 84 is directly connected to the bus bar 60. Therefore, the connection structure of the voltage detection line 84 is the unit cell 51. The space-saving structure can be achieved in the vertical direction (the thickness direction of the terminal forming surface 52A).

In the present embodiment, the FFC 84 (voltage detection line 84) and the bus bar 60 are sufficient to connect the voltage detection line 84 to the unit cell 51, so the number of parts can be reduced.
As a result, also according to the present embodiment, it is possible to provide the battery module 50 in which the connection structure of the voltage detection line 84 is reduced in size while reducing the number of parts required for the connection of the voltage detection line 84.

  Moreover, according to this embodiment, since FFC84 is used as the voltage detection line 84, since it can connect with the bus-bar 60 by low-cost methods, such as resistance welding and ultrasonic welding, cost can be reduced.

  By the way, when the conductor 85 of the FFC 84 and the bus bar 60 are connected by resistance welding, depending on the size of the welding electrode used, if the distance between the adjacent conductors 85 of the FFC 84 is small, one conductor 85 per bus bar 60 is used. May be difficult to connect. However, according to the present embodiment, every two adjacent conductors 85 are connected to one bus bar 60, and one circuit among the plurality of circuits formed by the connection between the conductor 85 and the bus bar 60 and another circuit are connected. Since one circuit is formed for one bus bar 60, there is an effect that the FFC 84 having a small interval between the conductors 85 can be used.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) Although the flexible flat cable is used as the voltage detection line in the above embodiment, a flexible printed circuit board (also referred to as FPC) may be used. The FPC and the bus bar can be connected by soldering or the like.
(2) In Embodiment 1 described above, a plurality of bus bars (connection members) integrated with an insulating resin portion are used. However, the plurality of bus bars may not be integrated.
(3) In the first embodiment, the FFC in which the mountain-folded folding part is formed in the portion disposed between the adjacent bus bars is shown, but the folding part may be a valley-folded one. Alternatively, the battery may be slacked in consideration of the expansion of the battery without folding the portion disposed between the adjacent bus bars.
(4) In the first embodiment, the battery module including the metal battery case and the separator having the protruding portion between the adjacent single cells is shown. However, the battery module may include a resin battery case. In this case, a separator is not necessary. Moreover, a metal battery case, a separator, and a short-circuit prevention member having a short-circuit prevention rib may be provided.
(5) In the second embodiment, two adjacent conductors are connected for each bus bar, but three or more conductors may be connected for each bus bar.
(6) As FFC, FFC produced by extrusion may be used.

DESCRIPTION OF SYMBOLS 10, 50 ... Battery module 11, 51 ... Single cell 12, 52 ... Battery case 12A ... Upper end surface (outer wall surface)
13A, 53A ... Electrode terminal (positive electrode)
13B, 53B ... Electrode terminal (negative electrode)
DESCRIPTION OF SYMBOLS 15 ... Separator 16 ... Protrusion part 20, 60 ... Bus-bar 22A ... Insulation resin part 24, 64 ... Terminal insertion hole 30, 84 ... Voltage detection line (flexible flat cable)
31 ... Mountain folding part (folding part)
32, 87 ... connecting portions 33, 86 ... (FFC) insulating resin 34, 85 ... conductor 88 ... dividing portion

Claims (6)

A battery module in which a plurality of single cells having positive and negative electrode terminals are arranged side by side,
A plurality of connecting members for electrically connecting the electrode terminals of the adjacent unit cells, and a voltage detection line for measuring the voltage of the unit cells,
The voltage detection line is a kind selected from a flexible flat cable in which the outer periphery of a flat conductor having a flat shape is surrounded by a flat shape with an insulating resin, and a flexible printed circuit board,
The battery module, wherein the connection member is directly connected to a conductor of the flexible flat cable or a conductor pattern of the flexible printed board. The battery module according to claim 1, wherein the plurality of connection members are integrated by an insulating resin portion formed by heat laminating an insulating resin film. The battery module according to claim 1, wherein the voltage detection line is a flexible flat cable. A portion of the flexible flat cable disposed between the adjacent connecting members is formed with a folded portion formed by folding the flexible flat cable with a fold line in a direction intersecting the length direction. The battery module according to claim 3. The unit cell has a metal battery case, and a resin separator having a protruding portion protruding outward from the outer wall surface of the battery case is disposed between the adjacent unit cells. The battery module according to any one of claims 1 to 4, wherein: The voltage detection line is a flexible flat cable formed by surrounding the outer periphery of a conductor row formed by paralleling a plurality of conductors in an insulated state in a flat shape with an insulating resin,
In the flexible flat cable, the plurality of conductors are connected to one connection member for each of a plurality of adjacent conductors, and among a plurality of circuits formed by connection of the plurality of conductors and the connection member, 6. The battery module according to claim 1, wherein one circuit is formed for each of the connection members by dividing one circuit from another circuit. 7. .

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