JP7147535B2 - battery pack - Google Patents

Description

The present disclosure relates to battery packs.

For example, Japanese Patent Laying-Open No. 2018-32519 (hereinafter referred to as “Patent Document 1”) discloses a battery module including a battery stack including a plurality of battery cells, a pair of end plates, a module case, and a module case. ing. The pair of end plates are arranged at both ends in the stacking direction of the battery stack. The module case accommodates the battery stack and the pair of end plates. The module case has a lower case that opens upward, and an upper cover that closes the opening of the lower case. The inner surface of the lower case facing each end plate has an inclined shape so that the dimension in the stacking direction of the battery stack gradually decreases (gradually approaches each other) from the opening of the lower case toward the bottom of the lower case. have. An outer side surface of each end plate facing the inner side surface of the module case is formed in a shape along the inner side surface. A battery stack consisting of a battery stack and a pair of end plates is press-fitted into the lower case. As a result, a restraining load is applied to the battery stack from the lower case.

JP 2018-32519 A

In the battery module described in Patent Document 1, in order to more reliably prevent the battery stack from being detached from the lower case, the frictional force generated between the end plates and the lower case is increased, that is, a large binding load is ensured. becomes necessary. To this end, it is required to increase the rigidity of the module case, but doing so increases the weight and cost of the module case.

An object of the present disclosure is to provide a battery pack capable of suppressing detachment of the secondary battery and the end plate from the battery case while suppressing an increase in the weight and cost of the battery case.

A battery pack according to the present disclosure includes: a plurality of secondary batteries arranged adjacent to each other; and a battery case that houses the plurality of secondary batteries and the pair of end plates. The battery case has a bottom wall that supports the plurality of secondary batteries, and side walls that stand up from both ends of the bottom wall in the adjacent direction. The pair of end plates has an outer surface facing the side wall in the adjacent direction, and the outer surface has a shape that slopes outward in the adjacent direction toward the bottom wall. The side wall has an inner side surface facing the outer side surfaces of the pair of end plates in the adjacent direction, and the inner side surface slopes outward in the adjacent direction toward the bottom wall. have a shape.

In this battery pack, the outer surface of the end plate and the inner surface of the battery case have a shape that slopes outward in the adjacent direction as it goes downward. In order to remove the stack of end plates from the battery case, it is necessary to compress the stack in the adjacent direction. Since the load in the direction of compressing the stack is hardly generated even by the vibration of the vehicle, the detachment of the stack from the battery case is effectively suppressed.

As described above, according to the present disclosure, there is provided a battery pack capable of suppressing detachment of the secondary battery and the end plate from the battery case while suppressing an increase in the weight and cost of the battery case. be able to.

1 is a cross-sectional view schematically showing the configuration of a battery pack according to an embodiment of the present disclosure; FIG.

Embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are given the same numbers.

FIG. 1 is a cross-sectional view schematically showing the configuration of a battery pack according to one embodiment of the present disclosure. The battery pack 1 of this embodiment is mounted, for example, in a vehicle interior. As shown in FIG. 1, the battery pack 1 has a plurality of secondary batteries 10, a pair of end plates 20, and a battery case 30. As shown in FIG.

Each secondary battery 10 is formed in a rectangular parallelepiped shape. The plurality of secondary batteries 10 are arranged so that an external electrode (not shown) of each secondary battery 10 is positioned at the top and adjacent to each other in the thickness direction of each secondary battery 10 . Spacers (not shown) made of resin are arranged between the secondary batteries 10 . Therefore, the unit made up of the plurality of secondary batteries 10 and the spacers can elastically expand and contract in the direction in which the plurality of secondary batteries 10 are adjacent to each other.

A pair of end plates 20 are provided at both ends of the plurality of secondary batteries 10 in the adjacent direction. Details of each end plate 20 will be described later.

The battery case 30 accommodates a plurality of secondary batteries 10 and a pair of end plates 20 . Battery case 30 has a shape that opens upward. Specifically, the battery case 30 has a bottom wall 32 and side walls 34 .

The bottom wall 32 supports multiple secondary batteries 10 . The bottom wall 32 is formed in a flat plate shape.

The side wall 34 has a shape rising from the end of the bottom wall 32 in the adjacent direction. The sidewall 34 has an inner surface 34S facing the end plate 20 in the adjacent direction. The inner side surface 34S has a shape that gradually widens outward in the adjoining direction from the upper end of the side wall 34 toward the lower end (as it approaches the bottom wall 32).

Each end plate 20 will now be described. Each end plate 20 has an outer surface (outer surface in the adjacent direction) 22S that faces the inner surface 34S of the side wall 34 . The outer surface 22S has a shape along the inner surface 34S. That is, the outer side surface 22S has a shape that slopes downward (as it approaches the bottom wall 32) so as to gradually widen outward in the adjoining direction. The inner side surface of each end plate 20 is configured to be parallel to the side surface of each secondary battery 10 (perpendicular to the bottom wall 32). That is, each end plate 20 has a shape in which the dimension in the adjacent direction gradually increases toward the bottom. In this embodiment each end plate 20 has a first plate element 21 and a second plate element 22 .

The first plate element 21 has a shape in which the dimension in the adjacent direction gradually increases toward the bottom. The first plate element 21 is provided adjacent to the outermost secondary battery 10 among the plurality of secondary batteries 10 . The dimension t1 in the adjacent direction of the lower end of the first plate element 21 is set smaller than the gap between the upper end of the outermost secondary battery 10 among the plurality of secondary batteries 10 and the upper end of the side wall 34. be done.

The second plate element 22 has a shape in which the dimension in the adjacent direction gradually decreases toward the bottom. The outer surface of the second plate element 22 in the adjacent direction constitutes the outer surface 22S. The second plate element 22 is arranged between the first plate element 21 and the sidewall 34 . The dimension t2 in the adjacent direction of the lower end of the second plate element 22 is smaller than the gap between the upper end of the first plate element 21 and the upper end of the side wall 34 and It is set substantially equal to or slightly smaller than the gap with the inner surface 34S. A dimension t3 in the adjacent direction of the upper end of the second plate element 22 is set substantially equal to or slightly smaller than the gap between the upper end of the first plate element 21 and the upper end of the side wall 34 . The second plate element 22 is inserted or press-fitted between the first plate element 21 and the side wall 34 after the plurality of secondary batteries 10 and the first plate element 21 are arranged in the battery case 30 . The second plate element 22 is then joined with the first plate element 21, if desired.

As described above, in the battery pack 1 of the present embodiment, the outer surface 22S of the end plate 20 and the inner surface 34S of the battery case 30 move downward (closer to the bottom wall 32) in the adjacent direction. Since it has an outwardly sloping shape, that is, the portion facing the bottom wall 32 of the stack consisting of the plurality of secondary batteries 10, spacers (not shown), and the pair of end plates 20 is adjacent to each other. Since the dimension in the direction is larger than the dimension in the adjacent direction of the opening of the battery case 30, it is necessary to compress the stack in the adjacent direction in order to remove the stack from the battery case 30 through the opening of the battery case 30. Since the load in the direction of compressing the stack is hardly generated even by vibrations of the vehicle, separation of the stack from the battery case 30 is effectively suppressed. Therefore, it is not necessary to provide a member or the like to press the stack from above toward the bottom wall 32 .

It should be noted that the embodiments disclosed this time are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and includes all modifications within the meaning and scope equivalent to the scope of the claims.

For example, the inner side surface 34S of one side wall 34 of the pair of side walls 34 arranged to face each other in the adjacent direction may be configured perpendicular to the bottom wall 32 . In this case, the outer surface 22S of the end plate 20 facing the side wall 34 is also configured perpendicular to the bottom wall 32 .

1 battery pack, 10 secondary battery, 20 end plate, 21 first plate element, 22 second plate element, 22S outer surface, 30 battery case, 32 bottom wall, 34 side wall, 34S inner surface.

Claims (1)

a plurality of secondary batteries arranged adjacent to each other;
a pair of end plates provided at both ends of the plurality of secondary batteries in an adjacent direction in which the plurality of secondary batteries are adjacent to each other;
a battery case that houses the plurality of secondary batteries and the pair of end plates;
The battery case includes a bottom wall that supports the plurality of secondary batteries;
and side walls rising from both ends of the bottom wall in the adjacent direction,
The pair of end plates has an outer side surface facing the side wall in the adjacent direction, and the outer side surface has a shape inclined so as to widen outward in the adjacent direction toward the bottom wall. ,
The sidewall has an inner surface facing the outer surfaces of the pair of end plates in the adjacent direction, and the inner surface slopes outward in the adjacent direction toward the bottom wall. having the shape
The pair of end plates are
It is provided so as to be adjacent to the outermost secondary battery in the adjacent direction among the plurality of secondary batteries, and has a shape in which the dimension in the adjacent direction gradually increases toward the bottom wall. a first plate element;
a second plate element disposed between the first plate element and the side wall and having a shape whose dimension in the adjacent direction gradually decreases toward the bottom wall;
The battery pack , wherein an outer surface of the second plate element in the adjacent direction constitutes the outer surface .

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