JP2015090798A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of achieving at least either capable of reducing the number of components or reducing a physique in comparison with before.SOLUTION: Since a lower case 31 extends in the lamination direction D of a laminate 21 on the lower side of the laminate 21 and a binding band lower portions 31a fixed to a pair of end plates 22, 22 are equipped therewith, two binding band lower portions which are conventionally required become unnecessary. Consequently, the number of components can be reduced in comparison with before, therefore, advantageous in cost. Moreover, since an arrangement space of two binding band lower portions can be eliminated in comparison with before, the physique in the upper and lower directions of the battery pack can be reduced and the physique in the lower and upper directions of the battery stack can be reduced in comparison with before.

Description

  The present invention relates to a battery pack having a battery stack and a case for housing the battery stack.

JP 2001-354039 A discloses a battery pack 1 having a battery stack 2 and a case 3 as shown in FIGS. 3 and 4.
The battery stack 2 includes a stacked body 2a of the square batteries 2a1, a pair of end plates 2b and 2b disposed on both sides in the stacking direction of the stacked body 2a, and extends in the stacking direction of the stacked body 2a on the upper side of the stacked body 2a. And two restraining band lowers 2d and 2d provided to extend in the stacking direction of the laminate 2a below the laminate 2a.
The case 3 accommodates the battery stack 2 and includes a lower case 3a and an upper case 3b.

However, since the battery pack 1 disclosed in the above publication requires two restraining bands 2c and 2d on the top and bottom of the laminate 2a, there is the following problem.
(A) The number of parts is large. Therefore, it is disadvantageous in terms of cost.
(A) The size of the battery stack 2 is increased, and the size of the battery pack 1 is increased.

JP 2001-354039 A

  An object of the present invention is to provide a battery pack that can achieve at least one of reducing the number of parts and reducing the physique as compared with the prior art.

The present invention for achieving the above object is as follows.
(1) having a battery stack and a case;
The battery stack includes a stacked body in which a plurality of rectangular batteries are stacked, a pair of end plates disposed on both sides in the stacking direction of the stacked body, and in the stacking direction of the stacked body on the upper side of the stacked body. A constraining band upper that is extended and fixed to the pair of end plates at both ends in the extending direction;
The case includes a lower case that supports the battery stack, and an upper case that is attached to the lower case, and accommodates the battery stack,
The lower case includes a constraining band lower portion that extends in a stacking direction of the stacked body below the stacked body and is fixed to the pair of end plates.
(2) The battery pack according to (1), wherein a state in which a restraint load is applied to the stacked body in the stacking direction is maintained by the restraint band upper and the lower case including the restraint band lower portion.

According to the battery pack of (1), since the lower case includes the restraining band lower portion that extends in the stacking direction of the stack and is fixed to the pair of end plates, it is necessary conventionally. Two restraint band lowers are not required. Therefore, the number of parts can be reduced as compared with the prior art, which is advantageous in terms of cost. In addition, since the space for disposing two restraint band lowers can be eliminated as compared with the prior art, the vertical physique of the battery stack can be reduced and the vertical physique of the battery pack can be reduced.

According to the battery pack of the above (2), the restraint band upper and the lower case include the restraint band upper and the lower case having the restraint band lower portion. The state where the restraint load is applied to the laminated body in the laminating direction can be maintained only by the above.

It is a schematic perspective view of the battery pack according to the embodiment of the present invention with the upper case omitted. It is an expanded sectional view of the battery pack of an example of the present invention. However, the cross-sectional display of the battery is omitted for clarity of the drawing. It is a disassembled perspective view of the conventional battery pack. It is sectional drawing of the conventional battery pack.

Below, the battery pack of an Example of this invention is demonstrated with reference to drawings.
The battery pack 10 according to the embodiment of the present invention is mounted on, for example, a hybrid vehicle, a battery vehicle, or the like. As shown in FIG. 2, the battery pack 10 includes a battery stack 20 and a case 30.

  As shown in FIG. 1, the battery stack 20 includes a stacked body 21, a pair of end plates 22 and 22, and a restraining band upper 23.

The stacked body 21 is formed by stacking a plurality of rectangular batteries 21a. Hereinafter, the stacking direction of the stacked body 21 (direction in which the batteries 21a are stacked) is referred to as a stacking direction D. Each battery 21a is a secondary battery, for example, a lithium ion battery. On the upper surface 21b of each battery 21a, positive and negative terminals (not shown) are provided.
The pair of end plates 22, 22 are arranged on both outer sides in the stacking direction of the stacked body 21. The end plate 22 is made of metal.

At least one restraining band upper 23 is provided. In the illustrated example, only one is shown. The restraining band upper 23 is provided on the upper side of the stacked body 21 so as to extend in the stacking direction D of the stacked body 21. The restraining band upper 23 is fixedly attached to the pair of end plates 22, 22 using bolts or the like at both ends in the extending direction of the restraining band upper 23.

The restraint band upper 23 is made of, for example, metal and is made of sheet metal. The restraint band upper 23 is provided in order to maintain a state in which the restraint load in the stacking direction D is applied to the stacked body 21. When the restraint load is relatively high and the restraint band upper 23 may be deformed by the reaction force from the laminated body 21, the restraint band upper 23 may be added by adding a bead, drawing or bending. Improvement of rigidity and strength may be achieved.

The case 30 is a case that houses the battery stack 20. As shown in FIG. 2, the case 30 includes a lower case 31 that fixes and supports (fastens and holds) the battery stack 20, and an upper case 32 that is disposed on the upper side of the lower case 31 and fixed and attached to the lower case 31.

Each of the lower case 31 and the upper case 32 is made of metal and is made of sheet metal. Each of the lower case 31 and the upper case 32 may have a multi-part configuration, but it is preferable that the lower case 31 and the upper case 32 have a single-part configuration in order to reduce the number of parts.

The lower case 31 includes a constrained band lower portion 31a extending in the stacking direction D of the stacked body 21 below the stacked body 21 (battery stack 20).

The restraint band lower portion 31a is fixedly attached to the pair of end plates 22, 22 using bolts or the like. The restraint band lower portion 31 a holds the state where the restraint load in the stacking direction D is applied to the stacked body 21. That is, the lower case 31 holds the battery stack 20 and holds the restraint load. In the present invention, the two conventionally required restraint band lowers are abolished, and the restraint load is applied to the laminate 21 in the stacking direction D only by the restraint band upper 23 and the restraint band lower portion 31a of the lower case 31. State is maintained.

When the restraint load is relatively high and the restraint band lower portion 31a (lower case 31) may be deformed by the reaction force from the laminate 21, by adding a bead, drawing or bending, etc., The restraint band lower part 31a (lower case 31) may be improved in rigidity and strength. When the constraining band lower portion 31a is subjected to drawing or bending in a direction perpendicular to the stacking direction D, a space S extending in the stacking direction D can be formed between the constraining band lower portion 31a and the stacked body 21. May be used as a cooling air flow path through which a refrigerant (for example, air) for cooling the battery 21a flows. In this case, measures against wind leakage may be taken using the seal member 40 or the like.

Next, the operation and effect of the embodiment of the present invention will be described.
(A) Since the lower case 31 includes a restraining band lower portion 31a that extends in the stacking direction D of the stacked body 21 and is fixed to the pair of end plates 22 and 22 on the lower side of the stacked body 21, it has been conventionally required. The function of the two restraint band lowers can be added to the lower case 21, so that the two restraint band lowers that have been conventionally required are not required. Therefore, the number of parts can be reduced as compared with the prior art, which is advantageous in terms of cost. Moreover, since the number of parts can be reduced, the number of assembling steps of the battery pack 10 can be reduced compared to the conventional case, which is advantageous in terms of cost.

(B) Since the two constraining band lowers conventionally required are not required, the space for disposing the two constraining band lowers can be eliminated as compared with the conventional case. Therefore, the vertical physique of the battery stack 20 can be reduced compared to the conventional case, and the vertical physique of the battery pack 10 can be reduced.

(C) Since the restraint band upper 23 and the lower case 31 including the restraint band lower portion 31a hold the restraint load in the stacking direction D on the laminate 21, the restraint band upper 23 and the lower case 31 only. Thus, it is possible to maintain a state in which a restraint load is applied to the stacked body 21 in the stacking direction D.

(D) When the rigidity and strength of the restraint band lower portion 31a (lower case 31) are improved by adding a bead, drawing or bending, etc., the rigidity and strength of the lower case 31 are improved and restrained. The rigidity as a function of the band (stiffness of the restraint part, rigidity of the restraint part) can also be improved.

(E) Since the lower case 31 is made of sheet metal, the degree of freedom of deformation processing (plastic processing) is higher than that of a conventional restraint band lower. Therefore, necessary rigidity and strength can be secured relatively easily without increasing the plate thickness.

DESCRIPTION OF SYMBOLS 10 Battery pack 20 Battery stack 21 Laminated body 21a Battery 21b Upper surface 22 of battery End plate 23 Restraint band upper 30 Case 31 Lower case 31a Restraint band lower part 32 Upper case D Stacking direction

Claims (2)

A battery stack and a case;
The battery stack includes a stacked body in which a plurality of rectangular batteries are stacked, a pair of end plates disposed on both sides in the stacking direction of the stacked body, and in the stacking direction of the stacked body on the upper side of the stacked body. A constraining band upper that is extended and fixed to the pair of end plates at both ends in the extending direction;
The case includes a lower case that supports the battery stack, and an upper case that is attached to the lower case, and accommodates the battery stack,
The lower case includes a constraining band lower portion that extends in a stacking direction of the stacked body below the stacked body and is fixed to the pair of end plates.   The battery pack according to claim 1, wherein a state in which a restraint load is applied to the stacked body in the stacking direction is maintained by the restraint band upper and the lower case including the restraint band lower portion.

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