JP6784100B2 - Battery module - Google Patents

Description

The present invention relates to a battery module.

As a battery module, for example, there is one described in Patent Document 1. The battery module of Patent Document 1 has an array in which a plurality of battery cells are arranged, and the array is connected by an end plate, a tie rod, or the like. An elastic body is arranged at the end of the array. Such an elastic body is supported by a middle plate arranged between the battery cell and the elastic body.

JP-A-2009-81056

In the battery module as described above, it is desirable that the middle plate that supports the elastic body has an increased flatness in order to restrain the elastic body during assembly. Therefore, it is conceivable to reduce the plate thickness in order to suppress the plate shrinkage. However, at the same time as increasing the flatness, it was also required to increase the strength.

Therefore, an object of the present invention is to provide a battery module capable of increasing the flatness of the middle plate and also increasing the strength.

The battery module according to one aspect of the present invention has an elastic body between the battery cell, an elastic body that absorbs vibration of the battery cell, a middle plate interposed between the battery cell and the elastic body, and the middle plate. In a second direction orthogonal to the first direction in which the battery cell, the middle plate, the elastic body, and the holding member are overlapped with the holding member to be sandwiched, the middle plate is outward from the battery cell and the elastic body. It has a first extension that extends, and the first extension has a fastening portion that is fastened to the fastening partner member by inserting a screw in the first direction, and a fastening portion that is fastened to the fastening partner member in the second direction. In the inner region, a first piercing portion in which the thickness of the first extension portion is thinned is formed, and is orthogonal to the first direction and the second direction of the first piercing portion. In the third direction, ribs are formed at positions corresponding to the fastening portions.

In the battery module, in the first extension portion of the middle plate, a first penetration portion in which the thickness of the first extension portion is thin is formed in a region inside the fastening portion in the second direction. ing. In this way, by forming the first meat penetration portion in the first extension portion of the middle plate, it is possible to suppress the plate shrinkage of the middle plate. Therefore, the flatness of the middle plate can be increased. On the other hand, the first extension portion of the middle plate has a fastening portion that is fastened to the fastening partner member by inserting a screw in the first direction. That is, when the fastening partner member is fastened to the fastening portion, the first extension portion receives a bending load. However, ribs are formed at positions corresponding to the fastening portions in the first through-cut portion in the first direction and the third direction orthogonal to the second direction. Therefore, even in a place where the first through-cut portion is formed and a bending load is likely to act, the strength of the middle plate can be increased by forming the ribs. From the above, the flatness of the middle plate can be increased and the strength can be increased.

The ribs may extend in the second direction. With such a configuration, the strength of the middle plate can be further increased.

The first through-hole portion is recessed from the elastic body side to the battery cell side in the first direction, and is located at a position other than the position corresponding to the fastening portion in the third direction of the first through-cut portion. In, ribs may be formed. With such a configuration, it is possible to prevent the middle plate from being depressed due to the load when the middle plate is brought into contact with the jig during assembly.

The middle plate has a second extension extending outward from the battery cell and the elastic body from the side opposite to the first extension in the second direction, and the second extension includes the second extension. A second meat-penetrating portion may be formed in which the thickness of the extension portion is reduced. With such a configuration, it is possible to increase the flatness and strength even on the second extension side.

According to the present invention, the flatness of the middle plate can be increased and the strength can be increased.

It is a top view which shows the battery module which concerns on embodiment of this invention. It is an enlarged sectional view of the structure around the middle plate shown in FIG. It is a front view of the middle plate shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 1 is a plan view showing a battery module. The battery module 1 shown in FIG. 1 is used, for example, in a state where a plurality of battery modules 1 are housed in a housing to form a battery pack.

As shown in FIG. 1, the battery module 1 has one of an array 15 in which a plurality of battery cells 11 are arranged while being held in the cell holder 21 and an array direction D (left-right direction in FIG. 1) of the array 15. An elastic body 31 arranged on the side (right side in FIG. 1), a pair of end plates (holding members) 41 arranged on both sides of the array body 15 and the elastic body 31 in the arrangement direction D, and a pair of end plates. It includes a plurality of bolts 51 that connect the 41s to each other, and a middle plate 61 that is arranged between the array body 15 and the elastic body 31.

The battery cell 11 is a battery in which the electrode assembly is housed in a rectangular box-shaped case, and is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. Seven battery cells 11 are arranged in this example. The battery cells 11 are arranged in a state of being held in the cell holder 21. Adjacent battery cells 11 are in close contact with each other via a heat transfer plate (not shown). The electrode terminals 13 of the adjacent battery cells 11 are electrically connected to each other by the bus bar 14, whereby the adjacent battery cells 11 are electrically connected in series. The array 15 is composed of the battery cell 11, the cell holder 21, the heat transfer plate 12, and the bus bar 14.

The elastic body 31 is formed in a flat plate shape by, for example, rubber. The elastic body 31 is arranged between the middle plate 61 and the end plate 41. The planar shape of the elastic bodies 31 as viewed from the arrangement direction D is, for example, a rectangular shape (rectangular shape), which is smaller than the outer shape of the middle plate 61. The elastic body 31 is assembled to, for example, the middle plate 61 by an engaging means (not shown), whereby the elastic body 31 is positioned with respect to the array body 15 in a direction orthogonal to the array direction D.

The end plate 41 is formed in a flat plate shape by, for example, metal. The pair of end plates 41 sandwich the array body 15 and the elastic body 31 from both sides in the arrangement direction D, and apply a restraining load to the array body 15 and the elastic body 31. The end plate 41 is provided with a plurality of through holes for inserting the bolts 51.

The bolt 51 is made of, for example, an iron-based metal having a relatively high strength. A plurality of bolts 51 are provided and extend in the arrangement direction D to connect the pair of end plates 41 to each other. Each of the plurality of bolts 51 is inserted into the through holes of the pair of end plates 41. Then, it is fastened with a nut 53 on the outside of one end plate 41. By this fastening, a restraining load is applied to the array body 15 and the elastic body 31. Further, the bolt 51 is also inserted into each of the through holes of the middle plate 61, which will be described later.

The middle plate 61 has, for example, a main body portion 60C (see FIG. 3) formed of a resin into a flat plate shape. The main body 60C is interposed between the array 15 and the elastic body 31. As a result, the variation in the load applied from the elastic body 31 to the array body 15 is suppressed. In the present embodiment, the planar shape of the main body 60C as viewed from the arrangement direction D is, for example, a rectangular shape, which is the same shape as the end plate 41.

FIG. 2 is a partially enlarged cross-sectional view showing a structure in which the middle plate 61 and the bus bar 72 (not shown in FIG. 1) are fastened with screws 71. As shown in FIG. 2, between the battery cell 11, the elastic body 31 that absorbs the vibration of the battery cell 11, the middle plate 61 interposed between the battery cell 11 and the elastic body 31, and the middle plate 61. An end plate 41 as a holding member for sandwiching the elastic body 31 is arranged. The XYZ axis coordinates are set for the battery module 1, and the following description will be given. The "Y-axis direction" corresponds to the "first direction" in the claim, the "Z-axis direction" corresponds to the "second direction" in the claim, and the "X-axis direction" corresponds to the "X-axis direction" in the claim. It corresponds to the "third direction".

The middle plate 61 is outside the battery cell 11 and the elastic body 31 in the Z-axis direction orthogonal to the Y-axis direction in which the battery cell 11, the middle plate 61, the elastic body 31, and the end plate (holding member) 41 are superposed. It has a first extension 60A extending to. As described above, the first extension portion 60A of the middle plate 61 is in a cantilevered state in which the proximal end side is supported by the battery cell 11 and the elastic body 31. The bus bar 72 is connected to the first extension portion 60A in the cantilever support state via a screw 71. The bus bar 72 is connected to the surface of the first extension portion 60A on the battery cell 11 side.

As shown in FIG. 3, the first extension portion 60A has a fastening portion 74 that is fastened to the bus bar 72, which is a fastening partner member, by inserting a screw 71 in the Y-axis direction, and a fastening portion in the Z-axis direction. In the region inside the 74, a first meat penetration portion 76 in which the thickness of the first extension portion 60A is thin is formed. In the present embodiment, a pair of fastening portions 74 are provided on the tip side of the first extension portion 60A in the Z-axis direction. The fastening portions 74 are arranged so as to be separated from each other in the X-axis direction in the vicinity of the central position of the first extension portion 60A in the X-axis direction. A through hole 77 for inserting the bolt 51 (see FIG. 1) is formed at a position adjacent to the fastening portion 74 in the X-axis direction.

The first meat penetration portion 76 is recessed from the elastic body 31 side toward the battery cell 11 side in the Y-axis direction (see FIG. 2). Further, in the first meat-penetrating portion 76, a region other than the outer peripheral edge portion is recessed so as to leave an outer peripheral rib 81 that traces the entire circumference of the outer peripheral edge portion of the first extension portion 60A. As a result, the first piercing portion 76 has the outer peripheral rib 81 and the thin plate portion 78 having a thickness (dimension in the Y-axis direction) thinner than the outer peripheral rib 81 in the region other than the rib described later. Each rib has a shape that protrudes from the thin plate portion 78 toward the elastic body 31 side. The portion of the outer peripheral rib 81 formed at the boundary position between the first extension portion 60A and the main body portion 60C is referred to as "boundary rib 81A" for the sake of explanation. In addition, the main body portion 60C in which the elastic body 31 is arranged also has a through portion formed, and the region other than the outer peripheral edge portion is configured as a thin plate portion 78. The first through-cut portion 76 (and other through-cut portions) and each rib are formed at the time of molding the middle plate 61.

A rib 80 is formed at a position corresponding to the fastening portion 74 in the X-axis direction of the first meat-penetrating portion 76. Further, the rib 80 is formed so as to extend in the Z-axis direction. In the present embodiment, the rib 80 extends straight in the Z-axis direction between the outer peripheral rib 81 near the fastening portion 74 and the boundary rib 81A. The ribs 80 extend from positions corresponding to both ends of the fastening portion 74 in the X-axis direction. However, the rib 80 may be provided at any position as long as it corresponds to the fastening portion 74. Further, a plurality of ribs 82 are formed at positions other than the positions corresponding to the fastening portions 74 in the X-axis direction of the first meat-penetrating portion 76. The rib 82 extends straight between the outer peripheral rib 81 on the distal end side and the boundary rib 81A along the X-axis direction. However, the position of the rib 82 to be formed in the X-axis direction and the number of ribs 82 to be formed are not particularly limited and can be changed as appropriate.

Further, the middle plate 61 has a second extension portion 60B extending outward from the battery cell 11 and the elastic body 31 from the side opposite to the first extension portion 60A in the Z-axis direction. Through holes 77 for inserting bolts 51 (see FIG. 1) are formed in the second extension portion 60B on both ends in the X-axis direction. Further, the second extension portion 60B is formed with a second meat-penetrating portion 79 in which the thickness of the second extension portion 60B is reduced. The second meat-penetrating portion 79 has a configuration in which the outer peripheral rib 83 remains and the thin plate portion 78 is formed, similarly to the first meat-penetrating portion 76. Further, a rib 84 extending in the Z-axis direction is formed at a predetermined position in the X-axis direction in the second meat-penetrating portion 79.

Next, the operation / effect of the battery module 1 according to the present embodiment will be described.

In the battery module 1, in the first extension portion 60A of the middle plate 61, the thickness of the first extension portion 60A is thinned in the region inside the fastening portion 74 in the Z-axis direction. Part 76 is formed. In this way, by forming the first through-hole portion 76 in the first extension portion 60A of the middle plate 61, the plate shrinkage during molding of the middle plate 61 (when the plate thickness is thick, the outer surface of the molded part). The plate bends due to the temperature difference between the inside and the inside) can be suppressed. Therefore, the flatness of the middle plate 61 can be increased. When assembling the elastic body 31, the middle plate 61 adjusts the thickness (that is, the compressive force) of the elastic body 31 while supporting the extension portions 60A and 60B with the jig SP (shown by the broken line in FIG. 3). To do. At this time, the flatness of the middle plate 61 is important, but in the present embodiment, the high flatness of the middle plate 61 can be ensured.

On the other hand, the first extension portion 60A of the middle plate 61 has a fastening portion 74 that is fastened to the bus bar 72, which is a fastening partner member, by inserting a screw 71 in the Y-axis direction. That is, when the bus bar 72, which is a fastening partner member, is fastened to the fastening portion 74, the first extension portion 60A in the cantilevered support state receives a bending load. However, the rib 80 is formed at a position corresponding to the fastening portion 74 in the X-axis direction of the first meat-penetrating portion 76. Therefore, the strength of the middle plate 60 is reduced by forming the first through-hole portion 76, and the strength of the middle plate 60 is reduced by forming the rib 80 even in a place where a bending load is likely to act. Can be enhanced. Therefore, the middle plate 61 can withstand a bending load. From the above, the flatness of the middle plate 61 can be increased and the strength can be increased.

The rib 80 extends in the Z-axis direction. With such a configuration, the strength of the middle plate 61 can be further increased.

The first meat penetration portion 76 is recessed from the elastic body 31 side in the Y-axis direction, and is recessed from the elastic body 31 side in the first meat penetration portion 76 at a position other than the position corresponding to the fastening portion 74 in the X-axis direction. , Ribs 82 are formed. For example, when the number of ribs in the first meat penetration portion 76 is small, when the jig SP is pressed against the middle plate, the load is concentrated on some of the ribs, and the middle plate 61 is depressed. There is a possibility that it will end up. On the other hand, since the substantial contact area with the jig SP is expanded by forming the rib 82 as in the present embodiment, when the middle plate 61 is brought into contact with the jig SP at the time of assembly, the middle plate 61 is brought into contact with the jig SP by a load. It is possible to prevent the plate 61 from collapsing.

The middle plate 61 has a second extension 60B extending outward from the battery cell 11 and the elastic body 31 from the side opposite to the first extension 60A in the Z-axis direction. The second extension portion 60B is formed with a second meat-penetrating portion 79 having a reduced thickness of the second extension portion 60B. With such a configuration, it is possible to improve the flatness and strength also on the second extension portion 60B side.

The present invention is not limited to the above-described embodiment.

For example, the shape, number, and extending direction of the ribs in the meat penetration portion are not limited to the above-described embodiment, and may be changed as appropriate. Further, a rib extending in the Z-axis direction may be formed in the through portion of the main body portion 60C. For example, a plurality of ribs extending straight in the Z-axis direction may be provided between the boundary rib of the first extension portion 60A and the boundary rib of the second extension portion 60B.

Further, the position of the fastening portion 74 of the middle plate 61 and the position and number of the through holes 77 may be appropriately changed.

Further, the meat penetration portion may be recessed from the battery cell 11 side toward the elastic body 31 side. Alternatively, the meat penetration portion may be recessed from both the battery cell 11 side and the elastic body 31 side.

1 ... Battery module, 11 ... Battery cell, 31 ... Elastic body, 41 ... End plate (holding member), 60A ... First extension, 60B ... Second extension, 61 ... Middle plate, 74 ... Fastening, 76 ... 1st meat penetration, 79 ... 2nd meat penetration, 80, 82 ... ribs.

Claims (4)

Battery cell and
An elastic body that absorbs the vibration of the battery cell and
A middle plate interposed between the battery cell and the elastic body,
A holding member that sandwiches the elastic body with the middle plate is provided.
In a second direction orthogonal to the first direction in which the battery cell, the middle plate, the elastic body, and the holding member are superposed, the middle plate extends outward from the battery cell and the elastic body. Has a first extension,
The first extension
By inserting the screw in the first direction, the fastening portion to be fastened to the fastening partner member and the fastening portion
Wherein the inner region than the engagement portion in a second direction, the first bored portions the thickness of the first extension portion is thin, is formed,
Of the first bored portions, in a third direction perpendicular to the first direction and the second direction, at a position corresponding to the fastening portion, the ribs are formed, the battery module. The battery module according to claim 1, wherein the rib extends in the second direction. The first lightening portion is recessed from the elastic body side to the battery cell side in the first direction.
The first of the thin portion, the second in the third direction, at a position other than the position corresponding to the fastening portion, the ribs are formed, the battery module according to claim 1 or 2. The middle plate has a second extension portion extending outward from the battery cell and the elastic body from a side opposite to the first extension portion in the second direction.
Wherein the second extension portion, the second lightening portion is thinner the thickness of the second extension portion is formed, the battery module according to any one of claims 1 to 3.

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