JP2014220131A - Restriction band structure of vehicle battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery module having a simple structure and having a high reliability, and to improve assemblability of the battery module and downsize the battery module.SOLUTION: In a restriction band structure of a vehicle battery module, a battery module having a plurality of battery cells and a pair of end plates provided at both ends in a lamination direction of the battery cells is provided, and a restriction band for fastening the battery cells is attached to the end plates, and the restriction band is fixed to the end plates via a fastening member. The fastening member comprises a projection part made of a thermoplastic resin protruding from an outside surface of the end plates toward the outside in the lamination direction of the battery cells. The projection part is inserted into an attachment hole of the restriction band. A front end part of the projection part protruded outward in the lamination direction of the battery cells from the attachment hole is pressed and heated to form on the projection part a skirt part that is larger than a diameter dimension of the attachment hole and that is attached on a surface of the restriction band. The restriction band is fastened to the end plates via the skirt part.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a restraint band structure for a battery module for a vehicle, and more particularly to a battery for a vehicle that has a simple structure, has high reliability, enhances battery module assembly, and reduces the size of the battery module. The present invention relates to a restraint band structure of a module.

The battery pack mounted on the vehicle is formed by a plurality of vehicle battery modules.
This battery module for vehicles has a plurality of battery cells to be stacked and a pair of end plates disposed at both ends in the stacking direction of the battery cells.
Further, the vehicle battery module uses a restraining band that sandwiches a pair of end plates and tightens a plurality of battery cells toward the center in the stacking direction.
At this time, in the vehicle battery module, a lithium ion battery is used as a battery cell.
And since the organic electrolyte used for this lithium ion battery volatilizes during charge and discharge, the internal pressure rises and the battery cell expands, a pair of resin-made end plates are arranged at both ends of the battery cell in the stacking direction. In addition, the vehicle battery module has a solid configuration in which the metal restraint band is clamped and fastened.

JP 2010-257651 A JP 2010-257652 A

By the way, in the conventional restraint band structure of the battery module for vehicles disclosed in Patent Literature 1 and Patent Literature 2, the restraint band and the end plate are fastened with rivets.
That is, when the vehicle battery module 102 is formed, as shown in FIG. 7A, a pair of end plates 105a are arranged at both ends in the stacking direction of the plurality of battery cells 103 and the separator 104, and the pair of end plates. The plurality of battery cells 103 are fastened to the center side in the stacking direction by sandwiching 105a with the restraining band 106.
A rivet 131 for fixing the end plate 105a of the battery module 102 and the restraining band 106 is disposed.
At this time, the rivet 131 uses a dedicated tool 133 so that the mounting hole 110 formed in the restraining band 106 and the mounting hole 132 formed in the end plate 105a are inserted from the outside of the restraining band 106. Arrange.
After the rivet 131 is arranged, as shown in FIG. 7B, the tool 133 pushes the tip 134 of the rivet 131 from the battery cell 103 side to the end plate 105a side, and the tip of the rivet 131 is pushed. The portion 134 is deformed to be larger than the mounting hole 132 of the end plate 105a.
Then, after the rivet 131 is deformed, as shown in FIG. 7C, the tool 133 is removed, and a part 133a of the tool 133 is left at the tip end portion 134 of the deformed rivet 131. The restraining band 106 is fastened to an end plate 105 a of the battery module 102.
However, in the conventional structure, it is necessary to insert the rivet 131 after aligning the mounting hole 110 of the restraining band 106 and the mounting hole 132 of the end plate 105a.
As a result, there is no positioning when aligning the mounting hole 110 of the restraining band 106 and the mounting hole 132 of the end plate 105a, and there is a disadvantage that the work load on the operator increases.
Further, since the rivet 131 is provided for fastening the restraint band 106 and the end plate 105a, between the end plate 105a and the battery cell 103, as shown in FIGS. 7A to 7C, A space S for inserting rivets and a tool for inserting rivets is required, and an extra space is formed between the end plate 105 a and the battery cell 103.
As a result, the entire length of the battery module 102 becomes long, and there is a disadvantage that it is difficult to reduce the size of the battery module 102.

  An object of the present invention is to provide a battery module having a simple structure and high reliability in a restraint band structure for a vehicle battery module, and to improve the assembly of the battery module and reduce the size of the battery module. To do.

  Therefore, in order to eliminate the above-described inconveniences, the present invention provides a battery module having a plurality of battery cells stacked on each other and a pair of end plates disposed at both ends in the stacking direction of the plurality of battery cells. A vehicle is provided with a restraining band that clamps the pair of end plates and clamps the plurality of battery cells to the center side in the stacking direction, and the restraining band is fixed to the end plate via a fastening member. In the restraint band structure of the battery module, the fastening member includes a projecting portion made of a thermoplastic resin projecting outward from the outer surface of the end plate in the stacking direction of the battery cell, and the projecting portion is attached to the mounting hole of the restraint band. And project outside the mounting holes in the stacking direction of the battery cells. By suppressing and heating the tip of the protruding portion, a skirt portion that is larger than the diameter of the mounting hole is formed in the protruding portion and is attached to the surface of the restraining band. The restraint band is fastened to the end plate.

According to the present invention, when the restraint band is attached to the end plate, the projecting portion attached to the end plate is positioned and the assembly of the restraint band to the end plate is facilitated by the above structure. it can.
In the present invention, only when the battery module is assembled, the protruding portion protrudes only on the outer side in the stacking direction of the battery cells.
When fastening the restraint band and the end plate, the restraint band and the end plate can be fastened by being plastically deformed by suppressing and heating the tip of the protrusion.
As a result, there is no need to provide a rivet and extra space for inserting a rivet tool as in the conventional structure between the end plate and the battery cell, and the battery module can be reduced in size.
Furthermore, the end plate and the restraining band can be firmly fastened by the skirt portion of the protruding portion by pressing and heating the protruding portion, thereby preventing the user from disassembling the battery module.
As a result, the battery cell can be prevented from being replaced by the user, so that the performance of the battery module can be maintained, and high reliability can be secured with a simple structure.

1A and 1B show a tightening state of a battery module by a restraining band, wherein FIG. 1A is a perspective view of a state in which end plates are positioned at both ends of a plurality of battery cells in a stacking direction, and FIG. (C) is a perspective view of a state where a restraining band is attached to the battery module, and (d) is a perspective view of a state where the battery module and the restraining band are fastened by a fastening member. Example 1 FIG. 2 is a plan view of the battery pack. Example 1 3A and 3B show a fastening state by a fastening member, wherein FIG. 3A is a perspective view of a state in which the battery module and the restraining band are fastened by the fastening member, and FIG. 3B is an enlarged perspective view of a main part of the fastening member portion. Example 1 4 shows an enlarged cross-sectional view of the main part taken along line IV-IV in FIG. 3, (a) is an enlarged cross-sectional view of the main part in a state in which a fastening member is disposed between the battery module and the restraining band, and (b) is a restraint with the battery module. It is a principal part expanded sectional view of the state fastened via the skirt part formed in the fastening member with the band. Example 1 FIG. 5 is an enlarged perspective view of the fastening member. Example 1 6A and 6B show the attachment state of the fastening member to the end plate, FIG. 6A is a perspective view showing the attachment state of the fastening member to the end plate, and FIG. 6B is an enlarged perspective view of the main part of the fastening member portion. (Example 2) 7A and 7B show the prior art of the present invention, in which FIG. 7A is a cross-sectional view showing a state where a rivet is arranged on the end plate of the battery module from the outside of the restraining band, and FIG. (C) is sectional drawing of the state which removed the tool and attached the restraint band to the end plate of the battery module by the rivet.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

1 to 5 show an embodiment of the present invention.
1 to 3, reference numeral 1 denotes a battery pack, and 2 denotes a vehicle battery module.
As shown in FIGS. 1 and 3, the battery module 2 includes a plurality of, for example, eight battery cells 3 stacked on each other, a stretchable separator 4 disposed between the battery cells 3, and a plurality of battery cells 3. The battery cell 3 has a pair of end plates 5a and 5b made of a resin material disposed at both ends in the stacking direction.
The pair of end plates 5a and 5b is provided with a metal restraining band 6 that sandwiches the pair of end plates 5a and 5b and fastens the plurality of battery cells 3 toward the center in the stacking direction.
The restraint band 6 is fixed to the pair of end plates 5 a and 5 b via the fastening member 7 to constitute the battery module 2.
Thereafter, a plurality of, for example, four sets of battery modules 2 are mounted on the mounting table 8, and the battery pack 1 to be mounted on a vehicle is configured as shown in FIG.

The fastening member 7 includes a protruding portion 9 made of a thermoplastic resin that protrudes outward from the outer surface of the end plates 5a and 5b in the stacking direction of the battery cells 3.
The protruding portion 9 is inserted into a mounting hole 10 formed in the restraining band 6.
And the front-end | tip part 11 of the said protrusion part 9 which protruded in the lamination direction of the said battery cell 3 rather than this attachment hole 10 is suppressed and heated.
As a result, a skirt portion 12 that is larger than the diameter of the mounting hole 10 and is attached to the surface of the restraining band 6 is formed in the projecting portion 9, and the restraining band 6 is inserted through the skirt portion 12. Fastened to the end plates 5a and 5b.
More specifically, when the battery module 2 is configured, as shown in FIG. 1A, first, the plurality of battery cells 3, the plurality of separators 4, and the battery cells 3 are arranged at both ends in the stacking direction. A pair of end plates 5a and 5b are arranged.
And the said fastening member 7 is attached to the outer side of a pair of end plate 5a, 5b as shown to Fig.1 (a) and (b).
Further, as shown in FIG. 1 (c), the projecting portion 9 of the fastening member 7 is inserted into the mounting hole 10 of the restraining band 6 to place the restraining band 6.
Thereafter, the distal end portion 11 of the protruding portion 9 of the fastening member 7 protruding outward from the mounting hole 10 of the restraining band 6 in the stacking direction of the battery cell 3 is suppressed and heated.
When the tip 11 of the protrusion 9 is suppressed and heated, the working direction of the tool (not shown) is changed from the outside of the battery module 2 to the stacking direction as shown by an arrow A in FIG. Can be done towards the center.
At this time, by applying plastic deformation to the tip 11 of the protrusion 9 of the fastening member 7 with a tool, the protrusion 9 of the fastening member 7 has a diameter of the mounting hole 10 as shown in FIGS. The skirt portion 12 that is larger than the dimension and is attached to the surface of the restraining band 6 is formed.
The restraint band 6 is fastened to the end plates 5a and 5b via the skirt portion 12.

Therefore, with the above structure, when the restraint band 6 is attached to the end plates 5a and 5b, the protruding portion 9 of the fastening member 7 attached to the end plates 5a and 5b is positioned, and the restraint band 6 6 can be easily assembled to the end plates 5a and 5b.
Further, in the present invention, only when the battery module 2 is assembled, the protruding portion 9 of the fastening member 7 protrudes only outward in the stacking direction of the battery cells 3.
When the restraint band 6 and the end plates 5a and 5b are fastened, the tip end portion 11 of the protrusion 9 is suppressed and heated to be plastically deformed, so that the restraint band 6 and the end plates 5a and 5b are compressed. Can be concluded.
This eliminates the need for providing extra space for inserting rivets and rivet tools as in the conventional structure between the end plates 5a and 5b and the battery cell 3, and the battery module 2 can be downsized.
Furthermore, by pressing and heating the protruding portion 9 of the fastening member 7, the end plates 5a, 5b and the restraining band 6 can be firmly fastened by the skirt portion 12 of the protruding portion 9. Disassembly of the battery module 2 can be prevented.
As a result, the battery cell 3 can be prevented from being replaced by the user, so that the performance of the battery module 2 can be maintained, and high reliability can be ensured with a simple structure.

The fastening member 7 is provided with a metal pedestal portion 14 to be mounted on the base portion 13 of the protruding portion 9, and the protruding portion 9 is attached to the end plates 5 a and 5 b via the pedestal portion 14.
That is, as shown in FIG. 5, the protruding portion 9 includes a cylindrical tip portion 11 having a dimension that can be inserted into the mounting hole 10 of the restraining band 6, and the end plates 5 a and 5 b of the tip portion 11. The base portion 13 is formed on the side and has a dimension that cannot be inserted into the mounting hole 10.
The base portion 13 of the protruding portion 9 is provided with the base portion 14 made of metal having a predetermined thickness and a dimension larger than that of the base portion 13, for example, formed in a prismatic shape.
Thereby, even if it presses and heats the said protrusion part 9 of the said fastening member 7 by setting it as the said structure, the heat added to the protrusion part 9 is made to the said end plates 5a and 5b by the said base part 14 made from metal. Direct transmission can be suppressed.
Further, high heat can be prevented from being transmitted from the end plates 5a, 5b to the battery cell 3.
As a result, it is possible to prevent thermal deformation of the end plates 5a and 5b and heat damage to the battery cell 3, thereby preventing the life of the battery module 2 from being lowered, and maintaining the high output of the battery module 2 to be high. Reliability can be secured.

Moreover, the recessed part 15 is formed in the position where the said fastening member 7 of the said end plates 5a and 5b is attached, and the said fastening member 7 is made to fit the said end plates 5a and 5b by fitting the said base part 14 and the said recessed part 15 together. It is fixed to.
That is, as shown in FIGS. 1 and 4, the plurality of recesses 15 are formed at positions where the fastening members 7 of the end plates 5a and 5b are attached, for example, at the four corners of the end plates 5a and 5b.
At this time, the concave portion 15 has a shape that matches the pedestal portion 14 of the fastening member 7. In addition, the depth dimension of the said recessed part 15 should just be a thing of the grade which the said fastening member 7 does not drop | omit when the said base part 14 is fitted to this recessed part 15, and can be set arbitrarily.
Thereby, by setting it as the said structure, the fastening member 7 can be fixed to the end plates 5a and 5b only by fitting the base part 14 of the said fastening member 7 in the said recessed part 15 of the said end plates 5a and 5b.
Further, an operation step such as adhesion between the fastening member 7 and the end plates 5a and 5b is not required, and the positioning of the fastening member 7 is facilitated by the concave portion 15 and the pedestal portion 14, thereby improving the assembling property. be able to.

If it adds, the assembly procedure of the said battery module 2 including the base part 14 and the said recessed part 15 of the said fastening member 7 will be as follows.
(1) The separators 4 are respectively arranged between the plurality of battery cells 3.
Then, a pair of end plates 5a and 5b are arranged at both ends of the battery cell 3 in the stacking direction to constitute the battery module 2 (see FIG. 1A).
(2) The pedestal portion 14 of the fastening member 7 is fitted into the recesses 15 formed at the four corners of the pair of end plates 5a and 5b (see FIGS. 1A and 1B).
(3) The jig is applied to a pair of end plates 5a and 5b, and the plurality of battery cells 3 and the separator 4 are pressed in the direction of arrow B toward the center in the stacking direction with this jig (FIG. 1B )reference.).
At this time, by pressing with the jig, the gap between the pair of end plates 5a and 5b of the battery module 2 is reduced, or the separator 4 and the like disposed in the gap is elastically deformed. The entire length between the end plates 5a and 5b contracts.
And since the full length between a pair of end plate 5a, 5b is compressed with the said jig | tool, from the front-end | tip part 11 of the protrusion part 9 of the said fastening member 7 attached to one end plate 5a to the other end plate 5b. The length dimension of the attached fastening member to the tip of the protruding portion becomes “L1-L2”, and the overall length dimension can be made smaller than the inner dimension “L3” of the restraint band 6.
In other words, if the jig is not pressed between the pair of end plates 5a and 5b, the fastening attached to the other end plate 5b from the tip 11 of the protruding portion 9 of the fastening member 7 attached to the one end plate 5a. The length dimension to the tip of the protruding portion of the member is “L1”, which is larger than the inner dimension “L3” of the restraining band 6.
However, by pressing between the pair of end plates 5a and 5b with the jig, the fastening attached to the other end plate 5b from the tip 11 of the protrusion 9 of the fastening member 7 attached to the one end plate 5a. Since the length to the tip of the protrusion of the member is “L1-L2”, it is smaller than the inner dimension “L3” of the restraining band 6.
(4) Then, the restraining band 6 is attached to the outside of the pair of end plates 5a and 5b in a state in which suppression is applied by the jig.
That is, the distal end portion 11 of the protruding portion 9 of the fastening member 7 fitted to the pair of end plates 5a and 5b is positioned in the vicinity of the mounting hole 10 of the restraining band 6, and the pressing force by the jig is released. To do.
Then, the contracted state is released, and the dimension obtained by reducing the dimension between the pair of end plates 5a, 5b to “L1-L2” by the shape recovery of the separator 4 increases in the direction of arrow C in FIG. By approaching the inner dimension “L3” of the restraining band 6, the distal end portion 11 of the protruding portion 9 of the fastening member 7 is inserted into the mounting hole 10 of the restraining band 6.
When the dimension between the pair of end plates 5a and 5b increases to the inner dimension “L3” of the restraining band 6, the pair of end plates 5a and 5b are accommodated in the inner dimension “L3” of the restraining band 6. (See FIG. 1 (c)).
(5) Thereafter, the tip 11 of the protrusion 9 of the fastening member 7 is suppressed by using a tool (not shown) from the outside of the battery module 2 as indicated by an arrow B in FIG. And heat.
Then, plastic deformation is applied to the distal end portion 11 of the projecting portion 9, and the skirt portion 12 that is larger than the diameter of the mounting hole 10 and is attached to the surface of the restraining band 6 is formed in the projecting portion 9. .
The restraint band 6 is fastened to the end plates 5a and 5b through the skirt portion 12 (see FIGS. 1D, 3 and 4).

FIG. 6 shows a second embodiment of the present invention.
In the second embodiment, portions that perform the same functions as those of the first embodiment will be described with the same reference numerals.

  The feature of the second embodiment is that an adhesive or the like is used when attaching the fastening member 21 to the outside of the pair of end plates 5a, 5b.

That is, the fastening member 21 is formed by a protruding portion 22 and a metal pedestal portion 23 attached to the protruding portion 22 as shown in FIG.
And the base part 23 of the said fastening member 21 is attached to the outer side of a pair of said end plate 5a, 5b using an adhesive agent.

If it is said, even if it presses and heats the said protrusion part 22 of the said fastening member 21 like the said 1st Example by setting it as the said structure, the heat added to the protrusion part 22 will be the said metal base. Direct transmission to the end plates 5a and 5b by the portion 23 can be suppressed. Moreover, it can suppress that high heat is transmitted from these end plates 5a and 5b to the battery cell. This prevents thermal deformation of the end plates 5a and 5b and heat damage to the battery cells, and as in the first embodiment, can prevent the life of the battery module from being reduced. To maintain high reliability.
Further, with the above structure, the fastening member 21 can be fixed to the end plates 5a and 5b as in the first embodiment.
Furthermore, after the restraint band is fastened, the bonding state between the outside of the pair of end plates 5a and 5b and the base portion 23 of the fastening member 21 is lowered and separated. However, since the plurality of battery cells are firmly fastened by the restraining band, there is no possibility that the battery module is disassembled into individual battery cells.

DESCRIPTION OF SYMBOLS 1 Battery pack 2 Vehicle battery module 3 Battery cell 4 Separator 5a, 5b A pair of end plate 6 Restraint band 7 Fastening member 8 Mounting base 9 Protruding part 10 Mounting hole 11 Tip part of projecting part 12 Skirt part 13 Base part of projecting part 14 Base 15 Recess

Claims (3)

  A battery module having a plurality of battery cells stacked on each other and a pair of end plates disposed at both ends in the stacking direction of the plurality of battery cells is provided, and the pair of end plates are sandwiched between the pair of end plates. In addition, in the restraint band structure of the vehicle battery module in which the restraint band for fastening the plurality of battery cells to the center side in the stacking direction is attached and the restraint band is fixed to the end plate via the fastening member, the fastening member includes the A protruding portion made of a thermoplastic resin protruding from the outer surface of the end plate to the outside in the stacking direction of the battery cells, the protruding portion being inserted into the mounting hole of the restraining band, and the stacking of the battery cells from the mounting hole; By suppressing and heating the tip of the protruding portion protruding outward in the direction The projecting portion is larger than the diameter of the mounting hole, and a skirt portion is formed on the surface of the restraint band, and the restraint band is fastened to the end plate via the skirt portion. A restraint band structure for a vehicle battery module.   2. The vehicle battery according to claim 1, wherein the fastening member includes a metal pedestal portion to be attached to a base portion of the protruding portion, and the protruding portion is attached to the end plate via the pedestal portion. Module restraint band structure.   The concave portion is formed at a position where the fastening member of the end plate is attached, and the fastening member is fixed to the end plate by fitting the pedestal portion and the concave portion. The restraint band structure of the battery module for vehicles.

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