JP2017033646A - Method of manufacturing battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a battery module capable of simply executing electrical connection between an electrode terminal of a battery cell and a circuit member.SOLUTION: In a method of manufacturing this battery module, after a feasible substrate 32 having a plurality of connection terminals 35, in each of which a pore part 35a fitted to an electrode terminal 20 is formed, is arranged upward of a battery module 1 in which the electrode terminal 20 of each battery cell 11 is arranged so as to be directed upward, and the flexible substrate 32 is descended to a descending position, where the connection terminal 35 becomes downward than the tip of the terminal 20, against the battery module 1, at the descending position, the flexible substrate 32 is relatively displaced in horizontal plane against the battery module 1, and the position of the connection terminal 35 to the electric terminal 20 is adjusted.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing a battery module.

  Conventionally, a battery module in which a plurality of battery cells such as lithium ion secondary batteries are arranged is known. A circuit member that detects a state quantity such as a voltage for each battery cell may be connected to the battery module for the purpose of monitoring the state of each battery cell. For example, a wire harness is used for electrical connection between the electrode terminal of the battery cell and the circuit member. However, the operation of connecting the wire harness to each of the electrode terminals of each battery cell is complicated, and a technique for improving the manufacturing efficiency of the battery module is required.

  In order to solve such a problem, it has been studied to use a flexible substrate such as a flexible printed circuit board as a circuit member. For example, in the battery module described in Patent Document 1, a voltage detection line for electrically connecting a positive electrode terminal or a negative electrode terminal of a battery cell and a voltage detection circuit is integrally formed on a flexible printed circuit board, thereby simplifying wiring. We are trying to make it.

International Publication No. 2010/113455

  As described above, by using a flexible substrate instead of the wire harness, it becomes possible to dramatically reduce the difficulty of handling. For this reason, the improvement of the manufacturing efficiency of a battery module is anticipated by automating the connection of the electrode terminal of a battery cell and a circuit member using a flexible substrate. On the other hand, when the connection is automated, the alignment of the electrode terminals of each battery cell and the connection terminals of the flexible substrate becomes a problem. The position of the electrode terminal in each battery cell of the battery module may vary depending on the dimensional tolerance of the battery cell and the assembling accuracy at the time of arrangement. Although it is possible to confirm the position of the connection terminal with respect to the electrode terminal using a camera or the like and perform highly accurate position adjustment, the equipment becomes complicated and there is a risk of increasing the cost.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for manufacturing a battery module that can easily perform electrical connection between an electrode terminal of a battery cell and a circuit member.

  In order to solve the above problems, a battery module manufacturing method according to one aspect of the present invention is a battery module manufacturing method in which a plurality of battery cells are arranged, and a circuit member is electrically connected to an electrode terminal of each battery cell. A connection process for connecting the battery terminals, and the connection process includes arranging a flexible substrate having a plurality of connection terminals formed with holes to be fitted to the electrode terminals so that the electrode terminals of each battery cell face upward. A placement step of placing the battery board above the battery module, a lowering step of lowering the flexible substrate with respect to the battery module to a lowering position where the connection terminal is below the tip of the electrode terminal, and a flexibility in the lowering position. Adjusting the position of the connection terminal relative to the electrode terminal by displacing the substrate relative to the battery module in a horizontal plane.

  In this battery module manufacturing method, the position of the connection terminal with respect to the electrode terminal is adjusted by relatively displacing the flexible substrate in the horizontal plane with respect to the battery module. Thereby, even if the position of the electrode terminal varies depending on the dimensional tolerance of the battery cell or the assembling accuracy at the time of arrangement, the position of the hole of the connection terminal can be adjusted to the position of the electrode terminal. When the position of the hole portion of the connection terminal matches the position of the electrode terminal, the connection terminal fits into the hole portion by its own weight, so that the electrical connection between the electrode terminal and the circuit member can be easily performed.

  Further, in the adjustment step, the flexible substrate may be displaced with respect to the battery module within a circular region having the radius of the maximum tolerance of the position of the electrode terminal in the battery module. If it carries out like this, the position of the hole of a connection terminal can be match | combined with the position of an electrode terminal, suppressing the displacement amount of the flexible substrate with respect to a battery module.

  In the adjustment step, the flexible substrate may be displaced linearly with respect to the battery module. In this case, the position of the hole of the connection terminal can be adjusted to the position of the electrode terminal by a simple displacement operation.

  In the adjustment step, the flexible substrate may be displaced in a circular shape or a vortex shape with respect to the battery module. In this case, the position of the hole of the connection terminal can be adjusted to the position of the electrode terminal by a simple displacement operation.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical connection of the electrode terminal of a battery cell and a circuit member can be implemented simply.

It is the schematic which shows an example of a battery module. It is the schematic which shows an example of a circuit member. It is a figure which shows the arrangement | positioning process included in the connection process of a battery module and a circuit member. It is a figure which shows the descent | fall process subsequent to an arrangement | positioning process. It is a figure which shows the mode of the malfunction of the connection which arises in a descent | fall process. It is a figure which shows the adjustment process following a descent | fall process. It is a figure which shows the example of the displacement of a flexible substrate in an adjustment process.

  Hereinafter, preferred embodiments of a battery module manufacturing method according to an aspect of the present invention will be described in detail with reference to the drawings.

  This battery module manufacturing method is a battery module manufacturing method in which a plurality of battery cells are arranged, and includes a connecting step of electrically connecting a circuit member to the electrode terminal of each battery cell. First, the structure of a battery module and a circuit member is demonstrated.

  As shown in FIG. 1, the battery module 1 includes an array body 2 in which a plurality of battery cells 11 are arrayed, a restraining member 3 that applies a restraining load to the array body 2 in the array direction of the battery cells 11, An elastic body 4 interposed between the array body 2 and the restraining member 3 is provided.

  In the array body 2, for example, a plurality of battery cells 11 are arrayed via a heat transfer plate 5. The heat transfer plate 5 is a metal flat plate member, but may be provided with a flow path groove for a temperature control medium such as cooling air. The battery cell 11 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. As shown in FIG. 1, the elastic body 4 is formed in a rectangular plate shape by, for example, a urethane rubber sponge. The area of the elastic body 4 is slightly smaller than the area of the side surface in the arrangement direction of the case 12 of the battery cell 11, for example, and is arranged at one end of the arrangement body 2 in the arrangement direction of the battery cell 11.

  Examples of the material for forming the elastic body 4 include ethylene propylene diene rubber (EPDM), chloroprene rubber, and silicon rubber. The elastic body 4 is not limited to rubber and may be a spring material or the like. The elastic body 4 is a member used for the purpose of preventing the battery cell 11 from being damaged by a restraining load, and may be disposed at both ends in the arrangement direction of the battery cell 11 or between the battery cells 11 and 11. May be.

  The restraining member 3 includes, for example, a pair of end plates 21 and a fastening member 22 that fastens the end plates 21 together. The end plate 21 has a substantially rectangular plate shape having an area larger than that when the battery cell 11 is viewed from the arrangement direction, for example, and the outer edge portion of the end plate 21 is outside the outer edge portion of the battery cell 11. Are arranged at both ends of the array body 2 and the elastic body 4 in the array direction.

  The fastening member 22 includes, for example, a long bolt 23 and a nut 24 that is screwed into the bolt 23. The bolts 23 are inserted into the end plate 21 at positions corresponding to the four corners of the array 2 at the outer edge portion of the end plate 21, for example. A nut 24 is screwed into one end of each bolt 23 from the outside of the end plate 21, whereby the battery cell 11, the elastic body 4, and the heat transfer plate 5 are sandwiched and unitized and a restraining load is applied. .

  As shown in FIG. 1, the battery cell 11 includes a hollow case 12 having a substantially rectangular parallelepiped shape, for example, and an electrode assembly (not shown) housed in the case 12. The case 12 is formed of a metal such as aluminum, for example, and an organic solvent-based or non-aqueous electrolyte is injected into the case 12, for example. A pair of electrode terminals 20 are disposed on the top surface of the case 12 so as to be separated from each other. One electrode terminal 20 is a positive electrode terminal and is electrically connected to the positive electrode of the electrode assembly. The other electrode terminal 20 is a negative electrode terminal and is electrically connected to the negative electrode of the electrode assembly. The electrode terminal 20 is comprised by the stud bolt, for example.

  As illustrated in FIG. 2, the circuit member 31 attached to the battery module 1 is, for example, a flexible printed circuit board, and includes a rectangular flexible substrate 32 and a plurality of terminal portions provided on the side surface of the flexible substrate 32. 33. The flexible substrate 32 is configured by bonding a conductive material to an insulating film such as polyimide, for example. For example, a voltage detection circuit that detects the voltage of the battery cell 11 in the battery module 1 is formed on the flexible substrate 32.

  The terminal portion 33 is provided on the side surface of the flexible substrate 32 according to the number of electrode terminals 20 installed in the battery module 1. The interval between the adjacent terminal portions 33 and 33 is set according to the interval between the electrode terminals 20 and 20 of the adjacent battery cells 11 and 11. The terminal portion 33 includes a wiring portion 34 having a certain flexibility like the flexible substrate 32 and a connection terminal 35 provided at the tip of the wiring portion 34. A hole 35 a that fits into the electrode terminal 20 of the battery cell 11 is provided in the approximate center of the connection terminal 35. The diameter of the hole 35 a is slightly larger than the diameter of the electrode terminal 20.

  In the connecting step, first, as shown in FIG. 3, the circuit member 31 is placed on the battery module 1 (placement step). More specifically, in the arranging step, the battery module 1 is arranged on a stage or the like so that the electrode terminals 20 of the respective battery cells 11 face upward. Further, the planar portion 32a of the flexible substrate 32 is sucked and supported by a robot arm or the like, and the circuit member 31 is attached to the battery module so that the position of the hole 35a of the connection terminal 35 corresponds to the position of the electrode terminal 20 of the battery cell 11. 1 above. In the arrangement step, the circuit member 31 may be at an arbitrary height position as long as it is a position above the tip of the electrode terminal 20.

  Next, as shown in FIG. 4, the circuit member 31 is lowered with respect to the battery module 1 (lowering step). In the descending step, the robot arm or the like that sucks and supports the flat portion 32a of the flexible substrate 32 is driven to lower the flexible substrate 32 to a predetermined lowered position. The lowered position is set, for example, at a position where the connection terminal 35 is below the tip of the electrode terminal 20, that is, a position where the lower side of the connection terminal 35 is below the tip of the electrode terminal 20.

  By lowering the flexible substrate 32 to a position where the connection terminal 35 is below the tip of the electrode terminal 20, at least the tip of the electrode terminal 20 is positioned in the hole 35 a of the connection terminal 35. Therefore, even if the suction support of the flexible substrate 32 by the robot arm or the like is canceled, the electrode member 20 can be fitted into the hole portion 35a of the connection terminal 35 by dropping the circuit member 31 by its own weight. The lowered position may be set to a position where the connection terminal 35 reaches the lower end of the electrode terminal 20. Here, the lower end of the electrode terminal 20 refers to the base end of the threaded portion of the stud bolt protruding from the top surface of the case 12. After fitting the electrode terminal 20 into the hole 35 a of the connection terminal 35, the nut of each electrode terminal 20 is fastened to complete the attachment of the circuit member 31 to the battery module 1.

  By the way, in the descent process mentioned above, alignment with the electrode terminal 20 of each battery cell 11 and the connection terminal 35 of the flexible substrate 32 becomes a subject. In general, the tolerance of the position of the connection terminal 35 on the flexible substrate 32 is sufficiently small with respect to the dimensional tolerance of the battery cell 11 and the assembly accuracy when the battery cell 11 is arranged. However, the position of the electrode terminal 20 in each battery cell 11 of the battery module 1 may vary depending on the dimensional tolerance of the battery cell 11 (dimensional tolerance of the case 12) and the assembling accuracy when the battery cells 11 are arranged.

  The tolerance of the position of the electrode terminal 20 increases according to the number of battery cells 11 arranged. For example, assuming that the tolerance of the position of the electrode terminals per cell is 0.1 mm, the maximum tolerance of the position of the electrode terminals is estimated to be 1.0 mm in a battery module having 10 cells. Therefore, even if the flexible substrate 32 is lowered with the position of the hole 35 a of the connection terminal 35 corresponding to the position of the electrode terminal 20 of the battery cell 11, the position of the electrode terminal 20 depends on the tolerance. If the position of the hole 35a is out of position, for example, as shown in FIG. 5, the connection terminal 35 may be caught on the tip of the electrode terminal 20, or the connection terminal 35 may get on the tip of the electrode terminal 20. Thus, it is conceivable that the electrode terminal 20 does not normally fit into the hole 35a of the connection terminal 35. Although it is possible to confirm the position of the connection terminal 35 with respect to the electrode terminal 20 using a camera or the like and perform highly accurate position adjustment, the equipment becomes complicated and there is a risk of increasing costs.

  In response to such a problem, in this battery module manufacturing method, after the flexible substrate 32 is lowered to a predetermined lowered position in the lowering step, the flexible substrate 32 is moved relative to the battery module 1 at the lowered position. The position of the connection terminal 35 relative to the electrode terminal 20 is adjusted by relatively displacing it in the horizontal plane (adjustment process). More specifically, in the adjustment step, the flexible substrate 32 is temporarily stopped at the lowered position, and the flat portion 32a is sucked and supported by a robot arm or the like as shown in FIG. The flexible substrate 32 is relatively displaced in the horizontal plane.

  By displacing the flexible substrate 32 in the horizontal plane with respect to the battery module 1, the position of the hole 35 a of the connection terminal 35 can be adjusted to the position of the electrode terminal 20. As a result, the electrode terminal 20 is fitted into the hole 35a of the connection terminal 35, and when the flexible substrate 32 is lowered to the lowered position, the electrode terminal 20 is hooked or climbs on the tip of the electrode terminal 20. The connection terminal 35 that has been connected is normally connected to the electrode terminal 20.

  For example, as shown in FIG. 7, the displacement of the flexible substrate 32 with respect to the battery module 1 is performed within a circular region R having the radius of the maximum tolerance of the position of the electrode terminal 20 in the battery module 1. When the maximum tolerance of the position of the electrode terminal 20 is 1.0 mm, the radius of the circular region R is 1.0 mm. As the displacement method, the flexible substrate 32 may be linearly displaced within the circular region R as shown in FIG. 7A, and the flexible substrate 32 as shown in FIG. 7B. May be displaced circularly within the circular region R. Further, as shown in FIG. 7C, the flexible substrate 32 may be displaced in a spiral shape within the circular region R.

  When the flexible substrate 32 is displaced linearly, as shown in FIG. 7A, for example, it passes through the center point of the circular region R (the point where the tolerance of the electrode terminal 20 is 0) O in the radial direction. Displace to. The direction of the displacement may be rotated around the center point O by a predetermined angle (for example, 45 °), and the flexible substrate 32 may be displaced a plurality of times in different directions. Further, the flexible substrate 32 may be displaced so as to vibrate in small increments.

  When the flexible substrate 32 is displaced circularly, it is displaced in the circumferential direction, for example, around the center point O of the circular region R as shown in FIG. The flexible substrate 32 may be displaced concentrically multiple times with different diameters. Further, the shape is not limited to a perfect circle, and may be displaced in an elliptical shape. When the flexible substrate 32 is displaced in a spiral shape, for example, the flexible substrate 32 is displaced from the center point O of the circular region toward the outer edge of the circular region R while gradually increasing the rotation diameter around the center point O. The direction of the displacement may be either clockwise or counterclockwise.

  As described above, in this battery module manufacturing method, the position of the connection terminal 35 with respect to the electrode terminal 20 is adjusted by relatively displacing the flexible substrate 32 in the horizontal plane with respect to the battery module 1. Thereby, even if the position of the electrode terminal 20 varies depending on the dimensional tolerance of the battery cell 11 or the assembling accuracy at the time of arrangement, the position of the hole 35a of the connection terminal 35 can be matched with the position of the electrode terminal 20. When the position of the hole 35a of the connection terminal 35 matches the position of the electrode terminal 20, the connection terminal 35 is fitted into the hole 35a by its own weight, so that the electrical connection between the electrode terminal 20 and the circuit member 31 can be easily performed. Can be implemented.

  In this method, it is not necessary to accurately detect the position of the connection terminal 35 with respect to the electrode terminal 20 using a camera or the like in the arrangement step of arranging the circuit member 31 with respect to the battery module 1, which complicates the equipment. Can also be avoided. Further, the connection of the circuit member 31 to the battery module 1 can be automated by a robot arm or the like. Therefore, the manufacturing cost of the battery module 1 can be reduced.

  In the present embodiment, the flexible substrate 32 is displaced with respect to the battery module 1 in the circular region R having the radius of the maximum tolerance of the position of the electrode terminal 20 in the battery module 1 in the adjustment step. In this way, the position of the hole 35 a of the connection terminal 35 can be aligned with the electrode terminal 20 while suppressing the amount of displacement of the flexible substrate 32 with respect to the battery module 1. In the present embodiment, the flexible substrate 32 is displaced linearly, circularly, or spirally with respect to the battery module 1 in the adjustment step. Thereby, the position of the hole 35a of the connection terminal 35 can be aligned with the electrode terminal 20 by a simple displacement operation.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the flexible substrate 32 is relatively displaced in the horizontal plane with respect to the battery module 1 in the adjustment step, but the flexible substrate 32 is not deviated from the effects of the present invention. You may displace relatively in an inclined surface. In the above embodiment, the flexible substrate 32 sucked and supported by a robot arm or the like is displaced with respect to the battery module 1, but the stage or the like on which the battery module 1 is placed is moved with respect to the flexible substrate 32. It may be displaced.

  Moreover, in the said embodiment, although the displacement of the flexible board | substrate 32 with respect to the battery module 1 is implemented in the circular area | region R which makes the radius the largest tolerance of the position of the electrode terminal 20 in the battery module 1, the electrode terminal 20 is implemented. The radius of the circular region R may be set in consideration of the difference between the outer diameter of the stud bolt constituting the inner diameter and the inner diameter of the hole 35a of the connection terminal 35. In this case, a value obtained by subtracting the difference between the outer diameter of the stud bolt and the inner diameter of the hole 35a of the connection terminal from the maximum tolerance of the position of the electrode terminal 20 may be set as the radius of the circular region R. For example, when the maximum tolerance of the position of the electrode terminal 20 is 5.0 mm, the outer diameter of the stud bolt is φ6.0 mm, and the inner diameter of the hole 35 a of the connection terminal 35 is φ8.0 mm, the radius of the circular region R Is 3.0 mm.

  DESCRIPTION OF SYMBOLS 1 ... Battery module, 11 ... Battery cell, 20 ... Electrode terminal, 31 ... Circuit member, 32 ... Flexible substrate, 35 ... Connection terminal, 35a ... Hole part, R ... Circular area | region.

Claims (4)

A battery module manufacturing method comprising a plurality of battery cells arranged,
A connection step of electrically connecting a circuit member to the electrode terminal of each battery cell;
The connecting step includes
Arrangement step of arranging a flexible substrate having a plurality of connection terminals in which holes to be fitted to the electrode terminals are arranged above the battery module in which the electrode terminals of the respective battery cells face upward. When,
A lowering step of lowering the flexible substrate with respect to the battery module to a lowered position where the connection terminal is below the tip of the electrode terminal;
An adjustment step of adjusting the position of the connection terminal with respect to the electrode terminal by displacing the flexible substrate relative to the battery module in a horizontal plane at the lowered position.   The battery module manufacturing method according to claim 1, wherein, in the adjustment step, the flexible substrate is displaced with respect to the battery module within a circular region having a radius of a maximum tolerance of the position of the electrode terminal in the battery module.   The battery module manufacturing method according to claim 1, wherein, in the adjustment step, the flexible substrate is linearly displaced with respect to the battery module.   The battery module manufacturing method according to claim 1 or 2, wherein, in the adjustment step, the flexible substrate is displaced in a circular shape or a vortex shape with respect to the battery module.

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