JP2013098032A - Connection structure of voltage detection terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection structure of a voltage detection terminal, which can connect the voltage detection terminal with a simple method.SOLUTION: The connection structure of the voltage detection terminal which is connected to an electrode terminal 20 and detects voltage of unit cells 11 includes: an FPC 30 arranged in a unit cell group 10, which has a main body part 31 that is arranged along an aligning direction of the unit cells 11 and has a conductive path 32B formed therein that is arranged so as to extend in the aligning direction of the unit cells 11. The FPC 30 has extended pieces 36 provided thereon which have a voltage detection terminal 38 and a conductive path 34 for detection that continues from one terminal of the conductive path 32B and is connected to the voltage detection terminal 38, and are integrally extended from the main body part 31. The extended piece 36 has such a shape as to extend in the aligning direction of the unit cells 11, and has the voltage detection terminal 38 electrically connected with the electrode terminal 20.

Description

  The present invention relates to a connection structure for voltage detection terminals.

  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, a general battery module has a structure (voltage detection structure) for detecting the voltage of the unit cell so that charging and discharging can be stopped before the abnormality occurs in the voltage between the unit cells. ing. The voltage detection structure includes, for example, a voltage detection terminal connected to the electrode terminal of the unit cell, a battery ECU, a voltage detection line connecting the voltage detection terminal and the ECU, and the like. The voltage of each unit cell is detected by the ECU, and charging and discharging are stopped before the overdischarge or overcharge state is reached.

  As a battery module provided with such a voltage detection structure, for example, a battery module described in Patent Document 1 is known.

JP 2011-124176 A

  Patent Document 1 proposes a configuration in which a voltage detection terminal in which an exposed conductor of a terminal of a voltage detection line is connected by crimping is inserted into an electrode terminal of a unit cell, and the electrode terminal is jointly fastened with a nut together with a connection member. (See FIG. 1 of Patent Document 1).

  However, in the battery module described in Patent Document 1, the operation of arranging the connection member and the voltage detection terminal in the connection unit, the operation of connecting a plurality of connection units in which the connection member and the voltage detection terminal are arranged, and the voltage detection terminal There is a problem that it takes time to connect the voltage detection terminal together with the connection member by fastening the nut to the electrode terminal by tightening the nut.

  The present invention has been completed based on the above-described circumstances, and an object thereof is to provide a voltage detection terminal connection structure that can be connected by a simple method.

In order to solve the above-mentioned problems, a study was made to form a plurality of voltage detection conductive paths on one flexible printed circuit board (hereinafter also referred to as FPC) and to connect to the cells constituting the cell group.
However, the unit cell group is configured by arranging a large number of unit cells, and manufacturing tolerances are set between the electrode terminals of the unit cells. Therefore, in a battery module in which a plurality of unit cells are arranged, it is formed in adjacent unit cells. In some cases, the pitch between the electrode terminals is shifted. In addition, the thickness of the unit cell may vary due to the expansion and contraction of the unit cell due to charge / discharge, and the pitch between the electrode terminals may shift. If the pitch deviation between the electrode terminals occurs in this way, there is a concern that the voltage connection cannot be performed due to a problem in the electrical connection between the member for voltage detection and the unit cell.

As a result of further studies, the present invention has been reached.
That is, the present invention provides a connection structure for a voltage detection terminal that is connected to the electrode terminal and detects the voltage of the unit cell, in a unit cell group formed by connecting a plurality of unit cells having positive and negative electrode terminals. And the flexible printed circuit board which has the main-body part by which the said battery cell group was formed along the arrangement direction of the said cell, and the conductive path extended and arranged in the arrangement direction of the said cell was formed. The flexible printed circuit board includes the voltage detection terminal and a detection conductive path connected to one of the terminals of the conductive path and connected to the voltage detection terminal. An extended extension piece is provided, and the extension piece has a shape extending in the arrangement direction of the unit cells, and the voltage detection terminal is electrically connected to the electrode terminal. With a butterfly.

  In the present invention, a flexible printed circuit board integrally provided with a main body portion in which a conductive path is formed and an extending piece having a detection conductive path and a voltage detection terminal connected from one end of the conductive path is provided. The voltage detection terminal can be connected to the single cell group simply by arranging the battery in the battery group and connecting the extension piece to the electrode terminal of the single cell. Therefore, according to this invention, the connection structure of the voltage detection terminal which can be connected by a simple method can be provided.

  In the present invention, since the extending piece has a shape extending in the arrangement direction of the unit cells, even if a deviation in the pitch between the electrode terminals occurs, the deviation can be absorbed by the extending piece. The electrical connection between the voltage detection terminal and the single cell can be ensured.

The present invention may have the following configuration.
The unit cell may be provided with an extension piece placement portion for placing the extension piece of the flexible printed board.
Since the extending piece has a shape extending in the arrangement direction of the cells, it may be bent in the middle. In such a case, there is a concern that the connection with the electrode terminal may be hindered. Then, if it is set as the above structures, since the extended piece of a flexible printed circuit board can be mounted in an extended piece mounting part, it can prevent bending. Moreover, if it is set as the above structures, since an extension piece can be mounted in a predetermined position, positioning of an extension piece becomes easy.

The positive electrode terminal and the negative electrode terminal are formed from a metal plate that protrudes from the battery body and can be bent and deformed in the direction in which the cells are arranged, and the tip of the electrode terminal of one polarity is adjacent to the electrode terminal. A connection piece that can contact the electrode terminal of the other polarity of the unit cell is provided, while the connection piece is received and sandwiched by the electrode terminal of the other polarity, and the extension of the flexible printed circuit board A spring member for receiving and sandwiching the piece may be provided, and the voltage detection terminal may be connected to the electrode terminal by sandwiching the extended piece of the flexible printed circuit board with the spring member.
With such a configuration, a connection member such as a bus bar is not required for connection between the cells, and the voltage detection terminal and the electrode terminal can be obtained simply by sandwiching the extended piece of the flexible printed circuit board with the spring member provided on the electrode terminal. Are connected, so that the number of parts can be reduced and work efficiency is excellent.

  The spring member may be integrally provided with a sandwiching spring part that sandwiches the connection piece part and an auxiliary spring part that sandwiches the extension piece. With such a configuration, the number of parts can be further reduced.

  The auxiliary spring portion may be formed with an extension piece insertion port into which the extension piece can be inserted along the cell arrangement direction. With such a configuration, the voltage detection terminal and the electrode terminal can be connected simply by inserting the extension piece into the extension piece insertion port and sandwiching the extension piece between the extension spring insertion portion, so that the work efficiency is improved.

In the flexible printed circuit board, an introduction piece introduced between the adjacent unit cells is provided integrally with the main body portion, and the main body portion has a conductive path other than the conductive path connected to the detection conductive path. The second conductive path is formed to extend in the direction in which the single cells are arranged, and the introduction piece includes an introduction line portion continuous from one end of the second conduction path, and a thermistor mounted on the introduction line portion. The thermistor may be attached to the unit cell group by inserting the introduction piece between the adjacent unit cells.
With such a configuration, it is possible to connect both the voltage detection circuit and the temperature control circuit by simply attaching one flexible printed circuit board to the single cell group, so that the connection work can be simplified and components can be connected. The score can also be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the connection structure of the voltage detection terminal which can be connected by a simple method can be provided.

The perspective view of the battery module of Embodiment 1. Plan view of battery module Partial sectional view showing the connection state of electrode terminals of adjacent unit cells Partial sectional view taken along line AA in FIG. Partially enlarged sectional view of FIG. Partial plan view of the battery module Partial sectional view taken along line BB in FIG. Front view of the positive terminal of the cell The perspective view explaining a mode that a flexible printed circuit board is attached to a cell group Partial enlarged plan view of flexible printed circuit board

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a battery module M according to an embodiment of the present invention. The battery module M of this embodiment is mounted on an electric vehicle, a hybrid vehicle, or the like, and is used as a driving power source. As shown in FIG. 1, the battery module M includes a unit cell group 10 and a flexible printed circuit board 30 (hereinafter also referred to as FPC 30). In the following description, the upper part of FIG.

  In the present embodiment, the unit cell group 10 includes a plurality of (in the present embodiment, 24) unit cells 11 arranged in a line and connected in series. Specifically, the unit cell 11 constituting the unit cell group 10 is composed of two types of unit cells 11A and 11B in which the extending directions of the electrode terminals 20 are different from each other. These two types of unit cells 11A and 11B are alternately arranged. The unit cell group 10 is configured by arranging and connecting.

  The unit cell 11 </ b> A includes a flat rectangular parallelepiped battery body 12 and a pair of positive and negative electrode terminals 20 (20 </ b> A, 20 </ b> B) protruding upward from the upper surface of the battery body 12.

  In the battery body 12, for example, a battery element (not shown) constituting a known lithium ion battery is accommodated, and the positive electrode side of the battery element is connected to the electrode terminal 20A and the negative electrode side is connected to the electrode terminal 20B.

  Of the pair of electrode terminals 20 of the unit cell 11A (see the second unit cell 11A from the left end in FIG. 1), one electrode terminal 20A on the near side in FIG. 1 is the positive electrode terminal 20A (positive terminal 20A). The other electrode terminal 20B on the back side is a negative electrode terminal 20B (negative electrode terminal 20B).

  Both the positive electrode terminal 20 </ b> A and the negative electrode terminal 20 </ b> B are made of a thin metal plate material that can be bent and deformed in the direction in which the cells 11 are arranged. As shown in FIGS. 1 and 3, the positive electrode terminal 20 </ b> A rises upward from the upper surface of the battery body 12, and is bent into an L shape from the upper end of the rising portion 21 </ b> A toward the near side (the left side in the drawing). A flat surface portion 22A and an operation portion 23 that inclines upward at the tip of the flat end portion 22A are provided.

  As shown in FIGS. 1 and 3, the negative electrode terminal 20 </ b> B has a rising portion 21 </ b> B that protrudes upward from the upper surface of the battery main body 12 of the unit cell 11, and is bent in an L shape from the upper end of the rising portion and ) Toward the flat surface portion 22B. The flat surface portion 22B of the negative electrode terminal 20B is a portion that is electrically connected to the positive electrode terminal 20A of the adjacent unit cell 11 (an example of a connection piece portion).

  In the negative electrode terminal 20B, the bending position is set so that the flat surface portion 22B is disposed below the flat surface portion 22A of the positive electrode terminal 20A as shown in FIG.

  As shown in FIG. 1, an insulating partition wall 15 is erected at a position adjacent to the negative electrode terminal 20 </ b> B on the upper surface of the battery body 12. The insulating partition 15 is set wider than the lateral width of the negative electrode terminal 20B, and a short circuit caused by a tool or member made of a conductive material falling between the electrode terminals 20A and 20B of different polarities of the adjacent unit cells 11 falls. It is preventing.

  A spring member 24 is attached to the flat surface portion 22A of the positive electrode terminal 20A. As shown in FIG. 8, the spring member 24 includes a holding spring portion 25 that receives and holds the flat surface portion 22B of the negative electrode terminal 20B, and an auxiliary spring portion that receives and holds the extending piece 36 (details will be described later) of the FPC 30. 26 is a member provided integrally. The spring member 24 is formed by pressing a metal plate that is separate from the positive electrode terminal 20 </ b> A and has excellent spring properties such as stainless steel.

  The sandwiching spring portion 25 is formed by forming a slit 25A extending in the width direction of the plate at one end of the metal plate, and turning the other end of the metal plate toward the slit 25A. The operation portion 23 of the positive electrode terminal 20A is penetrated through the slit 25A of the holding spring portion 25, and a single portion is provided between the flat surface portion 22A of the positive electrode terminal 20A and the inner peripheral edge of the lower side of the slit 25A of the holding spring portion 25. An insertion port 25B that receives the flat surface portion 22B of the negative electrode terminal 20B is formed along the direction in which the batteries 11 are arranged. When the flat surface portion 22B of the negative electrode terminal 20B is inserted into the insertion port 25B, the flat surface portion 22A of the positive electrode terminal 20A is pressed against the battery body 12 side (lower side) by the elastic force of the holding spring portion 25, and the negative electrode terminal 20B. Is pressed against the upper surface of the flat surface portion 22B.

As shown in FIG. 6, the auxiliary spring portion 26 has a configuration in which the configuration of the holding spring portion 25 is reduced in the width direction. Specifically, the auxiliary spring portion 26 is provided in parallel with the operation portion 23 of the positive electrode terminal 20A. The operation part 27 is made to penetrate through an auxiliary slit 26 </ b> A provided in the auxiliary spring part 26. In the auxiliary spring portion 26, an extension piece insertion port 26B that receives the extension piece 36 of the FPC 30 is formed between the auxiliary operation portion 27 of the positive electrode terminal 20A and the lower inner periphery of the auxiliary slit 26A.
The sandwiching spring portion 25 and the auxiliary spring portion 26 extend in conjunction with the opening of the extension piece insertion port 26B so that the insertion port 25B does not open. The slit 25A and the auxiliary slit 26A are separated by a notch (notch 28) so that the protruding piece insertion opening 26B does not open.

  Between the pair of positive and negative electrode terminals 20, a synthetic resin substrate mounting portion 16 on which the FPC 30 is mounted is provided so as to protrude upward. The substrate platform 16 includes a body platform 16A on which the body 31 of the FPC 30 is mounted, and an extended piece platform 16B on which the extended piece 36 of the FPC 30 is mounted. The height of the main body placing portion 16A and the extending piece placing portion 16B is set to be substantially the same as the height of the extending piece insertion port 26B of the auxiliary spring portion 26, and the extending piece 36 of the FPC 30 is set. Can be inserted into the extended piece insertion opening 26B without bending (see FIGS. 4, 5, and 7).

  The basic configuration of the unit cell 11B is the same as that of the unit cell 11A described above, and includes a battery body 12 and a pair of positive and negative electrode terminals 20A and 20B. However, in the unit cell 11B and the unit cell 11A, the directions in which the flat surface portions 22A and 22B of the electrode terminals 20A and 20B are bent in an L shape are reversed.

  A separator 17 made of an insulating resin is disposed between the adjacent unit cells 11A and 11B. As shown in FIG. 7, an introduction piece receiving hole 18 into which the introduction piece 33 of the FPC 30 can be inserted is provided at a substantially central portion of the separator 17.

  Although the FPC 30 attached to the unit cell group 10 is not shown in detail, a plurality of conductive paths 32 are formed by a printed wiring technique on one or both sides of an insulating base film made of, for example, a polyimide film or a liquid crystal film. (See FIGS. 6, 9, and 10), the surface of the conductive path 32 is covered with a protective film (for example, a polyimide film). 6 and 10 show only a conductive path 32B (also referred to as a first conductive path) constituting the voltage detection circuit, and FIG. 9 shows a conductive path 32A (an example of the second conductive path) constituting the temperature control circuit. In the other drawings, the conductive path 32 is not shown.

  The FPC 30 includes a strip-shaped (long-shaped) main body 31 (referred to as an FPC main body 31), a plurality of extending pieces 36 extending from the end in the width direction of the FPC main body 31, and the FPC main body 31. And two introduction pieces 33 provided substantially at the center.

  As shown in FIG. 2, the FPC main body portion 31 is placed on the main body placement portion 16 </ b> A of the substrate placement portion 16 and is disposed along the arrangement direction of the cells 11. A plurality of voltage detection circuit conductive paths 32B and two temperature control circuit conductive paths 32A are formed in the FPC main body 31 so as to extend in the arrangement direction of the cells 11 (FIG. 6, FIG. 6). (See FIGS. 9 and 10).

  The introduction piece 33 is provided by forming a rectangular cut at a substantially central portion in the width direction of the FPC main body 31 and has a rectangular shape. Each of the two introduction pieces 33 is provided with an introduction line portion 34 continuous from one end of the second conductive path 32A. A chip type NTC thermistor 35 is mounted on each lead-in portion 34. Each introduction piece 33 is inserted between adjacent unit cells 11A and 11B. In this embodiment, one introduction piece 33 is inserted for every eight unit cells 11. The introduction piece 33 inserted between the single cells 11 is received and accommodated in the introduction piece receiving hole 18 provided in the separator 17 (see FIG. 7).

  The other terminal of the second conductive path 32A is connected to an ECU (not shown). Information on the temperature obtained by the thermistor 35 is taken into the ECU through the lead-in portion 34 and the second conductive path 32A, and the temperature of each unit cell 11 is detected.

  Here, the ECU is equipped with a microcomputer, an element, and the like, and has functions for detecting the voltage, current, temperature, etc. of the unit cells 11 and controlling charge / discharge of each unit cell 11. It has a known configuration.

  Now, the extending piece 36 extends along the longitudinal direction of the FPC main body 31 and has a rectangular shape shorter than the introducing piece 33 (an example of a shape extending in the arrangement direction of the cells). The extending pieces 36 are alternately extended from the two end portions in the width direction of the FPC main body 31 to positions shifted in the longitudinal direction. Thereby, material collection can be improved rather than setting it as the structure which extends an extending piece from one edge. The extension piece 36 is placed on the extension piece placement portion 16 </ b> B of the substrate placement portion 16.

  As shown in FIG. 10, the extension piece 36 is formed with a detection conductive path 37 extending from one end of the first conductive path 32 </ b> B and extending to the end of the extension piece 36. At the end of the detection conductive path 37, the detection conductive path 37 is exposed by removing the film covering the detection conductive path 37. An exposed portion of the end portion of the detection conductive path 37 functions as a voltage detection terminal 38.

  The voltage detection terminal 38 of the extension piece 36 is electrically connected by being sandwiched between the auxiliary spring portions 26 attached to the positive electrode terminal 20A. For example, an ECU or the like is connected to the other terminal of the first conductive path 32B. Information about the voltage obtained at the voltage detection terminal 38 is taken into an ECU (not shown) through the detection conductive path 37 and the first conductive path 32B, and the voltage of each unit cell 11 is detected.

Next, a method for assembling the battery module M will be described.
First, the unit cell group 10 and the FPC 30 are produced. A conductive path 32 (first conductive path 32B, second conductive path 32A), a detection conductive path 37, a voltage detection terminal 38, and an introduction line portion 34 are formed, and a plurality of extending pieces 36 and introduction pieces 33 are formed. The thermistor 35, electronic components, and the like are mounted and connected to the FPC 30 having a predetermined shape, and the FPC 30 of this embodiment is manufactured.

  Next, a method for assembling the unit cell group 10 will be described. The unit cell group 10 uses a total of 24 two types of unit cells 11 (11A, 11B), and is arranged side by side on the same plane with the polarities of the electrode terminals 20A, 20B being alternately reversed. At this time, the separator 17 is disposed between the adjacent unit cells 11A and 11B so that the electrode terminal 20A of the unit cell 11A and the electrode terminal 20B of the unit cell 11B face each other.

  Next, when the unit cells 11A and the unit cells 11B are brought close to the arrangement direction of the unit cells 11, the flat surface portion 22B of the negative electrode terminal 20B and the insertion port 25B of the positive electrode terminal 20A are arranged to face each other, and the flat surface portion 22B. Is guided by the operation portion 23 of the electrode terminal 20A and is guided into the insertion port 25B.

  Further, when the unit cell 11A and the unit cell 11B are brought close to each other and the flat surface portion 22B is inserted into the insertion port 32, the spring member 24 is elastically restored, and the flat surface portion 22B of the negative electrode terminal 20B and the flat surface portion 22A of the positive electrode terminal 20A are connected. It is pressed by the elastic force of the spring member 24 (see FIG. 3). Thereby, the flat surface portion 22B of the negative electrode terminal 20B is sandwiched between the clamping spring portions provided in the positive electrode terminal 20A, and the assembly of the pair of unit cells 11A and 11B is completed. When such operations are repeated and 24 unit cells 11 (11A, 11B) are sequentially assembled, assembly of the unit cell group 10 is completed, and each unit cell 11 is connected to be conductive.

  Next, the FPC 30 is assembled to the upper surface of the unit cell group 10 from above (see FIG. 9). Specifically, the eighth cell 11A from the left and the ninth cell 11B from the left in FIG. 9 and the eighth cell 11B from the right and the ninth cell from the right in FIG. When the introduction piece 33 is introduced between the unit cells 11A, the introduction piece 33 is received in the introduction piece receiving hole 18 formed in the separator 17, and the attachment of the thermistor 35 is thereby completed.

  Next, when each extending piece 36 of the FPC 30 is inserted into the extending piece insertion port 26B of the auxiliary spring portion 26, the auxiliary spring portion 26 is elastically deformed, the extending piece insertion port 26B is opened, and the FPC 30 The extended piece 36 can be received. Further, when the extended piece 36 of the FPC 30 is inserted into the extended piece insertion port 26B, the auxiliary spring portion 26 is elastically restored, and the extended piece 36 of the FPC 30 and the flat surface portion 22A of the positive electrode terminal 20A are elastically springed. It is pressed by force (see FIG. 5). As a result, the FPC 30 is sandwiched between the auxiliary spring portions 26 provided on the positive electrode terminal 20 </ b> A, and the voltage detection terminal 38 provided on the extension piece 36 and the unit cell 11 can be electrically connected. When all the extending pieces 36 of the FPC 30 are sandwiched between the auxiliary spring portions 26, the battery module M is completed.

The operation and effect of this embodiment will be described.
In the present embodiment, the FPC main body 31 in which the conductive path 32 is formed and the extending piece 36 having the detection conductive path 34 and the voltage detection terminal 38 that are continuous from one end of the conductive path 32B are integrally provided. The voltage detection terminal 38 can be connected to the unit cell group 10 simply by arranging the FPC 30 in the unit cell group 10 and connecting the extension piece 36 to the electrode terminal of the unit cell 11. Therefore, according to the embodiment, it is possible to provide a connection structure of the voltage detection terminal 38 that can be connected by a simple method.

  By the way, in the battery module M in which the plurality of unit cells 11 are arranged, the thickness of the unit cells 11 varies due to manufacturing tolerances set for the unit cells 11 and expansion / contraction of the unit cells 11 due to charge / discharge. There is a case where a pitch deviation of. However, according to the present embodiment, since the extending piece 36 has a shape extending in the arrangement direction of the unit cells 11, even if a pitch shift between the electrode terminals 20 occurs, the extending piece 36 causes the shift. Therefore, the electrical connection between the voltage detection terminal 38 and the unit cell 11 can be ensured.

  Moreover, according to this embodiment, since the cell 11 is provided with the extended piece mounting portion 16B for mounting the extended piece 36 of the FPC 30, the extended piece 36 is used as the extended piece mounting portion. Since it can be placed on 16B, it is possible to prevent bending, and the extension piece 36 can be placed at a predetermined position, so that the extension piece 36 can be easily positioned.

  Further, in the present embodiment, the positive electrode terminal 20A and the negative electrode terminal 20B are formed to protrude from the battery body 12, and are formed from a metal plate material that can be bent and deformed in the arrangement direction of the single cells 11, and at the tip of the negative electrode terminal 20B The flat surface portion 22B (connection piece portion) that can contact the positive electrode terminal 20A of the adjacent unit cell 11 is provided, while the flat surface portion 22B is received and sandwiched between the positive electrode terminal 20A and the extension piece 36 of the FPC 30 is received. The spring member 24 is provided so as to be sandwiched between the voltage detection terminal 38 and the electrode member 20 by connecting the extension piece 36 to the spring member 24. As a result, according to the present embodiment, a connection member such as a bus bar is not necessary for connection between the single cells 11, and furthermore, the extending piece 36 of the FPC 30 is simply sandwiched between the spring members 24 provided on the positive electrode terminal 20 </ b> A. Since the voltage detection terminal 38 and the electrode terminal 20 are connected, the number of parts can be reduced and the working efficiency is excellent.

  In particular, in the present embodiment, the spring member 24 is integrally provided with a sandwiching spring portion 25 that sandwiches the flat surface portion 22B and an auxiliary spring portion 26 that sandwiches the extending piece 36. Can be reduced.

  Furthermore, according to the present embodiment, the extension piece 36 is formed in the auxiliary spring portion 26 since the extension piece insertion port 26B into which the extension piece 36 can be inserted along the arrangement direction of the cells 11 is formed. Since the voltage detection terminal 38 and the electrode terminal 20 can be connected simply by inserting the A into the extension piece insertion port 26B and sandwiching it between the auxiliary spring portions 26, the working efficiency is improved.

  In addition, in the present embodiment, the FPC 30 is provided with an introduction piece 33 that is introduced between the adjacent single cells 11 integrally with the FPC main body 31, and the FPC main body 31 has a first conductive material. A second conductive path 32A other than the path 32B is formed, and the introduction piece 33 is provided with an introduction line portion 34 continuous from one end of the second conduction path 32A and a thermistor 35 mounted on the introduction line portion 34. The thermistor 35 is attached to the unit cell group 10 by inserting the introduction piece 33 between the adjacent unit cells 11. As a result, according to the present embodiment, it is possible to connect both the voltage detection circuit and the temperature control circuit simply by attaching one FPC 30 to the single cell group 10, and thus the connection work can be simplified. The number of parts can be reduced.

<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) In the above embodiment, the unit cell 11 including the extended piece placement portion 16B is shown, but the extended piece placement portion 16B may not be provided.
(2) In the above embodiment, the unit cell 11 in which the electrode terminals 20 are directly connected to each other without using a connection member such as a bus bar is shown, but the present invention is not limited to this. For example, the voltage detection terminal provided in the extension piece of FPC may be inserted and connected to the electrode terminal of the unit cell which has a bolt-shaped electrode terminal.
(3) In the above embodiment, the sandwiching spring portion 25 and the auxiliary spring portion 26 are provided with the spring member 24 integrated. However, the sandwiching spring portion and the auxiliary spring portion may be separate. .
(4) In the above embodiment, the auxiliary spring portion 26 is formed with the extension piece insertion port 26B. However, the insertion spring port has an insertion port through which both the extension piece and the connection piece portion can be inserted. It may be provided.
(5) Although the said embodiment showed the thing of the structure by which the separator 17 is distribute | arranged between the single cells 11, you may not provide a separator.
(6) Although the FPC 30 including the voltage detection circuit and the temperature control circuit is shown in the above embodiment, the FPC including only the voltage detection circuit may be used.
(7) In the above embodiment, the voltage detection terminal is provided at the end of the detection conductive path 37 by exposing the detection conductive path 37. However, a conductive metal fitting is connected to the end of the detection conductive path. Thus, a voltage detection terminal may be configured.

M ... Battery module 10 ... Single cell group 11 ... Single cell 11A ... Single cell 11B ... Single cell 12 ... Battery body 16 ... Substrate placing part 16A ... Main body placing part 16B ... Extending piece placing part 20 ... Electrode terminal 20A ... Positive electrode terminal (positive terminal)
20B ... Negative electrode terminal (negative electrode terminal)
22A ... Flat surface portion (on the positive electrode terminal side) 22B ... Flat surface portion (on the negative electrode terminal side) (connection piece portion)
24 ... Spring member 25 ... Holding spring part 25B ... Insertion port 26 ... Auxiliary spring part 26B ... Extension piece insertion port 30 ... FPC (flexible printed circuit board)
31 ... FPC main unit (main unit)
32 ... conductive path 32A ... conductive path for temperature control circuit (second conductive path)
32B ... Conductive path (for voltage detection circuit) (first conductive path)
33 ... Introduction piece 34 ... Introduction wire portion 35 ... Thermistor 36 ... Extension piece 37 ... Detection conductive path 38 ... Voltage detection terminal

Claims (6)

A connection structure of a voltage detection terminal for detecting a voltage of the unit cell connected to the electrode terminal of a unit cell group formed by connecting a plurality of unit cells having a positive electrode and a negative electrode terminal,
In the unit cell group, a flexible printed circuit board having a main body formed with a conductive path arranged along the arrangement direction of the unit cells and extending in the arrangement direction of the unit cells is arranged,
The flexible printed circuit board has the voltage detection terminal and a detection conductive path connected to the voltage detection terminal from one end of the conductive path, and is integrally extended from the main body. An extension piece is provided,
The extension piece has a shape extending in the arrangement direction of the cells, and the voltage detection terminal is electrically connected to the electrode terminal. 2. The voltage detection terminal mounting structure according to claim 1, wherein the unit cell is provided with an extension piece placement portion on which the extension piece of the flexible printed board is placed. The positive electrode and negative electrode terminals are formed from a metal plate that protrudes from the battery body and can be bent and deformed in the direction in which the cells are arranged.
One end of the electrode terminal of one polarity is provided with a connection piece portion that can contact the electrode terminal of the other polarity of the adjacent unit cell, while the connection piece portion is provided on the electrode terminal of the other polarity. And a spring member for receiving and sandwiching the extended piece of the flexible printed circuit board is provided,
The voltage detection terminal connection structure according to claim 1, wherein the voltage detection terminal is connected to the electrode terminal by sandwiching the extended piece of the flexible printed board between the spring members. The voltage detection according to claim 3, wherein the spring member is integrally provided with a holding spring portion that holds the connection piece portion and an auxiliary spring portion that holds the extension piece. Terminal connection structure. 5. The connection of the voltage detection terminal according to claim 4, wherein the auxiliary spring portion is formed with an extension piece insertion port into which the extension piece can be inserted along the cell arrangement direction. Construction. In the flexible printed circuit board, an introduction piece introduced between the adjacent unit cells is provided integrally with the main body portion, and the main body portion has a conductive path other than the conductive path connected to the detection conductive path. A second conductive path is formed extending in the direction in which the unit cells are arranged,
The introduction piece is provided with an introduction line portion continuous from one end of the second conductive path and a thermistor mounted on the introduction line portion, and the introduction piece is inserted between the adjacent unit cells. The connection structure of the voltage detection terminal as described in any one of Claims 1 thru | or 5 by which the said thermistor is attached to the said cell group.

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