JP7018340B2 - Battery pack manufacturing method and battery pack - Google Patents

Description

The present invention relates to a method for manufacturing a battery pack in which a plurality of battery cells are compressed and sandwiched by an exterior body, and a battery pack.

Hybrid vehicles, electric vehicles, and the like are equipped with a battery pack in which a plurality of battery cells made of lithium ion secondary batteries and the like are stacked. Generally, a battery cell expands by charging and discharging. Therefore, in the battery pack, a plurality of battery cells are stacked and arranged between a pair of end plates, and the entire plurality of battery cells including the end plates are compressed and sandwiched by an exterior body called a bind bar. , It is configured to suppress the expansion of the battery cell (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2013-51048 Japanese Unexamined Patent Publication No. 2017-216114

In order to effectively suppress the expansion of the plurality of stacked battery cells, it is important that each of the plurality of exterior bodies evenly exerts a compressive force on the plurality of battery cells. For this purpose, each exterior body needs to have uniform strength and rigidity.

Generally, the exterior body is formed with high strength and high rigidity, and is flexed and assembled with respect to a plurality of stacked battery packs, so that the reaction force of the exterior body is used to apply a compressive force to the battery pack. There is. However, if a dimensional tolerance (variation in finished dimensions) occurs for each exterior body, each exterior body cannot evenly apply a compressive force to a plurality of stacked battery cells, and the battery cell There is a problem that the expansion cannot be effectively suppressed.

Therefore, an object of the present invention is to provide a method for manufacturing a battery pack and a battery pack having an exterior body capable of easily applying a uniform compressive force to the battery cell.

(1) In the method for manufacturing a battery pack according to the present invention, a plurality of battery cells (for example, the battery cell 10 described later) are laminated between a pair of end plates (for example, the end plate 20 described later), and the pair is described. A method for manufacturing a battery pack (for example, a battery pack 1 described later) in which an end plate and the plurality of battery cells are compressed and sandwiched by a plurality of exterior bodies, wherein the pair of end plates and the plurality of battery cells are used. After integrally extruding and molding an exterior body member having a shape extending over the upper surface, side surfaces, and bottom surface (for example, the exterior body member 100 described later), a side wall portion of the exterior body member corresponding to the side surface (for example, described later). 10. The top plate member (for example, the top plate member 60 described later) and the bottom plate member (for example, the bottom plate member 70 described later) are separately formed, and then the side surfaces of both ends of the top plate member and the bottom plate member. The pair of end plates and the plurality of battery cells are arranged between the support portions, and the pair of end plates are fixed to the side surface support portions of the top plate member and the bottom plate member, respectively.

According to (1), the dimensions of the top plate member and the bottom plate member of the exterior body can be made uniform, and the dimensional difference between the top plate member and the bottom plate member is reduced, so that the structural reliability is improved and the battery cell is used. It is possible to provide a method for manufacturing a battery pack having an exterior body capable of easily applying a uniform compressive force to the battery pack. In addition, since the top plate member and the bottom plate member are integrally processed, the manufacturing cost is also reduced.

(2) In the method for manufacturing a battery pack according to (1), a direction (for example, a direction described later) in which the top plate member separately formed from the exterior body member intersects with the extrusion direction of the exterior body member. A side plate member (for example, the side plate member 80 described later) having side support portions (for example, the side plate support portion 82 described later) is further divided and formed by cutting over a certain width along D2), and then the side plate member 80 is further divided and formed. The pair of end plates and the plurality of battery cells are arranged between the side surface support portions at both ends of the top plate member, the bottom plate member, and the side plate member, and the top plate member, the bottom plate member, and the like. It is preferable to fix the pair of end plates to the side surface support portions of the side plate members.

According to (2), the dimensions of the top plate member, the bottom plate member, and the side plate member can be made uniform, and the dimensional difference between the top plate member, the bottom plate member, and the side plate member is reduced. Therefore, the structural reliability of the battery pack can be further improved, and a battery pack capable of easily applying a uniform compressive force to the battery cell can be easily obtained. Further, since the side plate member is integrally processed with the top plate member and then divided, the manufacturing cost can be further reduced.

(3) In the method for manufacturing a battery pack according to (1) or (2), when the exterior body member is extruded, a mounting portion (for example, a mounting portion) projecting to both outer sides of the side surface support portion of the bottom plate member is used. It is preferable to integrally extrude the mounting portion 73) described later at the same time.

According to (3), since the mounting portion for mounting the battery pack to the mounting target portion is also integrally molded with the bottom plate member during extrusion molding, a structure for mounting the battery pack to the mounting target portion can be easily formed.

(4) In the battery pack according to the present invention, a plurality of battery cells (for example, the battery cell 10 described later) are laminated between a pair of end plates (for example, the end plate 20 described later), and the pair of end plates and the battery pack described below are stacked. The plurality of battery cells are a battery pack (for example, a battery pack 1 described later) that is compressed and sandwiched by a plurality of exterior bodies, and the exterior body is a top plate member (for example, a top plate member 60 described later). ) And the bottom plate member (for example, the bottom plate member 70 described later), and the top plate member and the bottom plate member have side support portions (for example, the side surface support portion 62 described later) corresponding to the pair of end plates at both ends. 72), the distance between the inner surfaces of the side surface support portions of the top plate member (for example, the distance W11 described later) and the distance between the inner surfaces of the side surface support portions of the bottom plate member (for example, the distance described later). W21) is equal to, and the distance between the outer surfaces of the side surface support portions of the top plate member (for example, the distance W12 described later) and the distance between the outer surfaces of the side surface support portions of the bottom plate member (for example, described later). The distance W22) is equal to, and the pair of end plates are fixed to the side support portions of the top plate member and the bottom plate member, respectively.

According to (4), the dimensions of the top plate member and the bottom plate member are aligned, and the dimensional difference between the top plate member and the bottom plate member is reduced. Further, since the width direction (D2 direction) of the battery cell can be uniformly compressed, the battery pack can be provided with an exterior body capable of preventing local deformation of the battery cell. Since the dimensions of the top plate member and the bottom plate member are the same, the top plate member and the bottom plate member can be integrally extruded and molded, the productivity is good, and the cost of the battery pack can be reduced. ..

(5) In the battery pack according to (4), the exterior body is a side plate member (for example, described later) having side support portions (for example, side surface support portions 82 described later) corresponding to the pair of end plates at both ends. The distance between the inner surfaces of the side surface support portions of the side plate member (for example, the distance W31 described later) is equal to the distance between the inner surfaces of the side surface support portions of the top plate member. Moreover, the distance between the outer surfaces of the side surface support portion of the side plate member (for example, the distance W32 described later) and the distance between the outer surfaces of the side surface support portion of the top plate member are equal, and the distance between the outer surfaces of the side plate member is equal to the above. The protrusion height of the side surface support portion (for example, the protrusion height H3 described later) and the protrusion height of the side surface support portion of the top plate member (for example, the protrusion height H1 described later) are equal to each other, and the top plate is said to be equal. The sum of the width of the member (for example, the width U described later) and the width of the side plate member (for example, the width S described later) is equal to the width of the bottom plate member (for example, the width L described later), and the side plate member said. It is preferable that the pair of end plates are fixed to the side surface support portion.

According to (5), in order to enable the bus bar connection work between the electrode terminals of the battery cell after fixing the top plate member, even if the top plate member is arranged only between the electrode terminals of the battery cell, it is combined with the side plate member. Therefore, it becomes possible to evenly compress the top plate member side and the bottom plate member side of the battery cell, and it is possible to prevent local deformation of the battery cell. Further, since the width of the top plate member and the width of the side plate member are equal to the width of the bottom plate member, each member can be separately formed after the top plate member, the bottom plate member, and the side plate member are integrally extruded and molded. Productivity can be improved and the cost of the battery pack can be further reduced.

(6) In the battery pack according to (4) or (5), the mounting portion (for example, the mounting portion 73 described later) integrally projects on both outer sides of the side surface support portion of the bottom plate member. preferable.

(6) makes it possible to integrally form a flange portion for fastening bolts for fixing the battery pack to the mounting target portion, and it is possible to reduce the manufacturing cost of parts.

According to the present invention, it is possible to provide a method for manufacturing a battery pack and a battery pack having an exterior body capable of easily applying a uniform compressive force to the battery cell.

It is a perspective view of the battery pack which concerns on one Embodiment of this invention. It is an exploded perspective view of the battery pack shown in FIG. It is a front view of the top plate member of the exterior body of the battery pack shown in FIG. 1. It is a front view of the bottom plate member of the exterior body of the battery pack shown in FIG. 1. It is a front view of the side plate member of the exterior body of the battery pack shown in FIG. 1. It is a figure explaining the exterior body of the battery pack which concerns on one Embodiment of this invention. It is a figure explaining the manufacturing method of the battery pack which concerns on one Embodiment of this invention. It is a figure explaining the manufacturing method of the battery pack which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Battery pack configuration]
FIG. 1 is a perspective view of a battery pack according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the battery pack shown in FIG. FIG. 3 is a front view of the top plate member of the exterior body of the battery pack shown in FIG. FIG. 4 is a front view of the bottom plate member of the exterior body of the battery pack shown in FIG. FIG. 5 is a front view of a side plate member of the exterior body of the battery pack shown in FIG. 1. FIG. 6 is a diagram illustrating an exterior body of a battery pack according to an embodiment of the present invention.
As shown in FIGS. 1 and 2, the battery pack 1 has a plurality of battery cells 10 stacked in parallel between a pair of end plates 20 and 20. As shown in FIG. 2, an insulating plate 13 is sandwiched between the adjacent battery cells 10 and 10 and between the battery cell 10 at the end and the end plate 20.

Here, as shown in FIG. 1, in the battery pack 1, the direction along the stacking direction of the plurality of battery cells 10 is defined as the "D1 direction". Further, the direction orthogonal to the D1 direction and parallel to the upper surface 10a of the battery cell 10 is defined as the "D2 direction". Further, a direction orthogonal to the D1 direction and the D2 direction and perpendicular to the upper surface 3a of the battery cell 10 is defined as the "D3 direction". Further, "top" and "bottom" in the battery pack 1 correspond to the top and bottom of each figure.

A plurality of battery cells 10 laminated together with the insulating plate 13 are covered with an insulating cover 40 over the side surface and the lower surface along the stacking direction (D1 direction) of the battery cells 10. Further, side plates 50 are attached to both side surfaces of the battery cells 10 along the stacking direction (D1 direction).

The side plate 50 is in contact with the side surface of the plurality of battery cells 10 covered with the insulating cover 40 along the stacking direction (D1 direction) with the insulating cover 40 interposed therebetween. The side plate 50 has a mounting piece 52 integrally bent and formed so as to abut on the bottom surface of the insulating cover 40. A plurality of screw holes 53 are formed in the mounting piece 52.

The plurality of stacked battery cells 10 have an end plate 20, an insulating cover 40, and a side plate 50, and are surrounded by an exterior body. The exterior body is made of a metal material or a resin material having high strength and high rigidity. The exterior body of the present embodiment includes a top plate member 60 provided on the upper surface 10a side of the battery cell 10, a bottom plate member 70 provided on the lower surface side of the battery cell 10, and a side surface along the stacking direction (D1 direction) of the battery cell 10. It is composed of a side plate member 80 provided in the above.

The top plate member 60 has a top plate portion 61 and a side surface support portion 62. The top plate portion 61 is arranged so as to cover the upper surface 10a of all the battery cells 10 including the pair of end plates 20 and 20 in the stacking direction (D1 direction). The top plate portion 61 covers the inside of the pair of electrode terminals 10b and 10b provided on the upper surface 10a of the battery cell 10. That is, the length of the top plate portion 61 along the D2 direction is shorter than the separation distance between the pair of electrode terminals 10b and 10b of the battery cell 10. Therefore, a pair of electrode terminals 10b and 10b of each battery cell 10 are exposed on the outer side of the top plate portion 61 along the D2 direction.

The side surface support portions 62 are integrally formed at both ends of the top plate portion 61 along the direction D1 so as to extend downward along the D3 direction. In the top plate member 60 of the present embodiment, there are no portions formed along the D1 direction, the D2 direction, and the D3 direction other than the top plate portion 61 and the side surface support portion 62.

The width of the side surface support portion 62 (width along the D2 direction in FIGS. 1 and 2) is the same as the width of the top plate portion 61 (width along the D2 direction in FIGS. 1 and 2). The side surface support portions 62 are side surfaces arranged at both ends of the stacked battery cells 10 in the stacking direction (D1 direction), specifically, a pair of end plates 20 and 20 sandwiching the stacked battery cells 10. The outer surface (the side surface opposite to the battery cell 10 along the D2 direction) 20a, 20a is abutted so as to cover and support the end plates 20, 20.

As shown in FIG. 3, the two side support portions 62, 62 of the present embodiment have the same downward protrusion height H1. The protruding height H1 of the side surface support portion 62 is set to be about ½ of the height of the end plate 20 (height along the D3 direction). Further, the distance W11 between the inner surfaces of the pair of side surface support portions 62, 62 is set to be slightly smaller than the distance between the outer surfaces 20a, 20a of the pair of end plates 20, 20.

The cross-sectional shape when the top plate member 60 is cut along the D1 direction is formed so as to have exactly the same shape regardless of the position in the D2 direction. Therefore, the thicknesses of the top plate portion 61 and the side surface support portion 62 are uniform along the D2 direction. The side surface support portion 62 of the present embodiment has a uniform thickness in the protruding direction along the D3 direction.

The bottom plate member 70 has a bottom plate portion 71, a side surface support portion 72, and a mounting portion 73. The bottom plate portion 71 is arranged so as to cover the bottom surfaces of all the battery cells 10 including the pair of end plates 20 and 20 in the stacking direction (D1 direction). The length of the bottom plate portion 71 along the D2 direction is substantially equal to the length of the insulating cover 40 along the D2 direction. Therefore, the bottom plate portion 71 is formed so as to cover the entire lower surface of the insulating cover 40.

The side surface support portions 72 extend upward along the D3 direction and are integrally formed at both ends of the bottom plate portion 71 along the D1 direction. The width of the side surface support portion 72 (width along the D2 direction in FIGS. 1 and 2) is the same as the width of the bottom plate portion 71 (width along the D2 direction in FIGS. 1 and 2). Similar to the side support portion 62 of the top plate member 60, the side support portion 72 is a side surface arranged at both ends of the stacked battery cells 10 in the stacking direction (D1 direction), specifically, the stacked batteries. The pair of end plates 20 and 20 sandwiching the cell 10 are brought into contact with each other so as to cover the outer surfaces 20a and 20a, and the end plates 20 and 20 are supported.

As shown in FIG. 4, the two side support portions 72, 72 of the present embodiment have the same upward protrusion height H2. The protruding height H2 of the side surface support portion 72 is set to be about ½ of the height of the end plate 20 (height along the D3 direction). Further, the distance W21 between the inner surfaces of the pair of side surface support portions 72, 72 is set to be slightly smaller than the distance between the outer surfaces 20a, 20a of the pair of end plates 20, 20.

The mounting portion 73 is provided on both outer sides of the pair of side surface support portions 72, 72 so as to project integrally in parallel with the bottom plate portion 71. The mounting portion 73 is a portion to be mounted by a plurality of bolts (not shown) with respect to a mounting target portion such as a vehicle on which the battery pack 1 is mounted. Since the mounting portion 73 is provided so as to integrally project from the bottom plate portion 71, it becomes possible to integrally form a flange portion for fastening bolts for fixing the battery pack 1 to the mounting target portion. The manufacturing cost of parts can be reduced. The width of the mounting portion 73 (width along the D2 direction in FIGS. 1 and 2) is the same as the width of the bottom plate portion 71 (width along the D2 direction in FIGS. 1 and 2). In the bottom plate member 70 of the present embodiment, there are no portions formed along the D1 direction, the D2 direction, and the D3 direction other than the bottom plate portion 71, the side surface support portion 72, and the mounting portion 73.

The cross-sectional shape when the bottom plate member 70 is cut along the D1 direction is formed so as to have exactly the same shape regardless of the position in the D2 direction. Therefore, the thicknesses of the bottom plate portion 71, the side surface support portion 72, and the mounting portion 73 are uniform along the D2 direction. The side surface support portion 72 of the present embodiment has a uniform thickness in the protruding direction along the D3 direction.

The total height of the protruding height H1 of the side surface support portion 62 of the top plate member 60 and the protruding height H2 of the side surface support portion 72 of the bottom plate member 70 is the height direction of the battery cell 10 including the insulating cover 40. It is set to be less than or equal to the dimension (D3 direction).

The side plate member 80 has a side plate portion 81 and a side surface support portion 82. The side plate portion 81 is arranged along the length direction of the side plate 50 along the stacking direction (D1 direction) of the battery cells 10. The length of the side plate portion 81 along the D3 direction is sufficiently shorter than the height of the side plate 50 along the D3 direction.

The side surface support portions 82 extend in parallel with the end plate 20 along the D2 direction and are integrally formed at both ends of the side plate members 80 along the D1 direction. In the side plate member 80 of the present embodiment, there is no portion formed along the D1 direction, the D2 direction, and the D3 direction other than the side plate portion 81 and the side surface support portion 82.

The width of the side surface support portion 82 (width along the D3 direction in FIGS. 1 and 2) is the same as the width of the side plate portion 81 (width along the D3 direction in FIGS. 1 and 2). Similar to the side surface support portion 62 of the top plate member 60, the side surface support portion 82 sandwiches an end surface of the stacked battery cells 10 in the stacking direction (D2 direction), specifically, the stacked battery cells 10. It abuts on the outer surfaces 20a, 20a of the pair of end plates 20, 20 and supports the end plates 20, 20.

In the two side plate members 80, 80 of the present embodiment, the widths of the side plate portions 81, 81 shown in FIG. 2 along the direction D3 are the same. Further, as shown in FIG. 5, the protrusion heights H3 of the two side surface support portions 82 and 82 of the present embodiment are also the same. The protrusion height H3 of the side surface support portions 82 and 82 is equal to the protrusion height H1 of the side surface support portion 62 of the top plate member 60. Further, the distance W31 between the inner surfaces of the pair of side surface support portions 82, 82 is set to be slightly smaller than the distance between the outer surfaces 20a, 20a of the pair of end plates 20, 20.

The cross-sectional shape when the side plate member 80 is cut along the D1 direction is formed so as to have exactly the same shape regardless of the position in the D3 direction. Therefore, the thickness of each side plate portion 81 and each side surface support portion 82 is uniform along the D3 direction. The side surface support portion 82 of the present embodiment has a uniform thickness in the protruding direction along the D2 direction. Furthermore, the cross-sectional shape when the side plate member 80 is cut along the D1 direction is the same as the cross-sectional shape when the top plate member 60 is cut along the D1 direction.

The relationship between the dimensions of the top plate member 60, the bottom plate member 70, and the side plate member 80 will be further described with reference to FIGS. 3 to 6. The side plate members 80, 80 shown in FIG. 6 are arranged by rotating the angle by 90 degrees so that the D3 direction shown in FIG. 2 is along the D2 direction in FIG. 6 in order to facilitate the understanding of the explanation. There is.
As shown in FIG. 6, the sum of the width U of the top plate member 60 along the D2 direction and the widths S and S of the two side plate members 80 and 80 along the D2 direction is the sum of the widths S and S of the bottom plate member 70 in the D2 direction. Is equal to the width L along. That is, U + S + S = L.

Further, as shown in FIGS. 3 to 5, the distance W11 between the inner surfaces of the pair of side surface support portions 62 and 62 of the top plate member 60 and the distance between the inner surfaces of the pair of side surface support portions 72 and 72 of the bottom plate member 70. W21 is equal to, and the distance W12 between the outer surfaces of the pair of side surface support portions 62, 62 of the top plate member 60 and the distance W22 between the outer surfaces of the pair of side surface support portions 72, 72 of the bottom plate member 70 are equal to each other. equal. That is, W11 = W21 and W12 = W22.

Further, as shown in FIGS. 3 to 5, the distance W31 between the inner surfaces of the pair of side surface support portions 82 and 82 of the side plate member 80 and the distance between the inner surfaces of the pair of side surface support portions 62 and 62 of the top plate member 60. W11 is equal to, and the distance W32 between the outer surfaces of the pair of side surface support portions 82, 82 of the side plate member 80 and the distance W12 between the outer surfaces of the pair of side surface support portions 62, 62 of the top plate member 60 are equal to each other. equal. That is, W11 = W31 and W12 = W32. As described above, since W11 = W21 and W12 = W22, the relationship is eventually W11 = W21 = W31 and W12 = W22 = W32.

The top plate member 60, the bottom plate member 70, and the side plate member 80 are mounted so as to surround the upper surface, side surface, and bottom surface of the battery cell 10 which is sandwiched between the pair of end plates 20 and 20 and housed in the insulating cover 40. ..

Specifically, the top plate member 60 is mounted on the upper surface 10a of the stacked battery cells 10. Since the distance W11 between the inner surfaces of the pair of side support portions 62, 62 is slightly smaller than the distance between the outer surfaces 20a, 20a of the pair of end plates 20, 20, the side surface support portions 62 are slightly outward. While bending and deforming, it comes into contact with the outer surface 20a of the end plate 20. At this time, the pair of side surface support portions 62, 62 compresses and sandwiches the pair of end plates 20, 20 due to the reaction force due to the strength and rigidity of the top plate member 60. As a result, a plurality of battery cells 10 sandwiched between the pair of end plates 20 and 20 are arranged between the pair of side surface support portions 62 and 62 of the top plate member 60. As shown in FIGS. 1 and 2, the side surface support portion 62 of the top plate member 60 is fixed to the end plate 20 by a plurality of bolts 63.

Further, the bottom plate member 70 is attached to the lower surface of the insulating cover 40 accommodating the stacked battery cells 10. Since the distance W21 between the inner surfaces of the pair of side support portions 72, 72 is slightly smaller than the distance between the outer surfaces 20a, 20a of the pair of end plates 20, 20, the side surface support portions 72 are slightly outward. While bending and deforming, it comes into contact with the outer surface 20a of the end plate 20. At this time, the pair of side surface support portions 72, 72 compresses and sandwiches the pair of end plates 20, 20 due to the strength and reaction force of the bottom plate member 70. As a result, a plurality of battery cells 10 sandwiched between the pair of end plates 20 and 20 are arranged between the pair of side surface support portions 72 and 72 of the bottom plate member 70. As shown in FIGS. 1 and 2, the side surface support portion 72 of the bottom plate member 70 is fixed to the end plate 20 by a plurality of bolts 74. Further, as shown in FIG. 2, the bottom plate portion 71 of the bottom plate member 70 is fixed to the mounting piece 52 of the side plate 50 by a plurality of bolts 75.

Further, the side plate member 80 is attached to the side plate 50. Since the distance W31 between the inner surfaces of the pair of side support portions 82, 82 is slightly smaller than the distance between the outer surfaces 20a, 20a of the pair of end plates 20, 20, the side surface support portions 82 are slightly outward. While bending and deforming, it comes into contact with the outer surface 20a of the end plate 20. At this time, the pair of side surface support portions 82, 82 compresses and sandwiches the pair of end plates 20, 20 due to the reaction force due to the strength and rigidity of the side plate member 80. As a result, a plurality of battery cells 10 sandwiched between the pair of end plates 20 and 20 are arranged between the pair of side surface support portions 82 and 82 of the side plate member 80. As shown in FIGS. 1 and 2, the side plate portion 81 of the side plate member 80 is caulked and fixed to the side plate 50 by a caulking pin 83 via through holes 51 and 51 provided at both ends of the side plate 50. .. Further, as shown in FIGS. 1 and 2, the side surface support portion 82 of the side plate member 80 is fixed to the end plate 20 by a plurality of bolts 84.

As shown in FIGS. 1 and 2, the end plates 20 and 20 are provided with terminal blocks 11 and 11, respectively. The terminal block 11 is fixed to the outer surface 20a and the upper surface 20b of the end plate 20 by bolts 14, respectively.

The battery pack 1 configured in this way has the same dimensions as the top plate member 60 and the bottom plate member 70. Therefore, due to the exterior body in which the dimensional difference between the top plate member 60 and the bottom plate member 70 is reduced, the width direction (D2) of the battery cell 10 on the top plate member 60 side and the bottom plate member 70 side, and further on the battery cell 10. Since the direction) can be evenly compressed, local deformation of the battery cell 10 can be prevented. Further, the structural reliability of the battery pack 1 is improved, and a uniform compressive force can be easily applied to the plurality of stacked battery cells 10. Further, in the battery pack 1 of the present embodiment, the dimensions of the side plate member 80 are also the same as those of the top plate member 60 and the bottom plate member 70, so that the structural reliability of the battery pack 1 can be further improved.

Further, the distance W31 between the inner surfaces of the side surface support portions 82 and 82 of the side plate member 80 and the distance between the inner surfaces of the side surface support portions 62 and 62 of the top plate member 60 are equal, and the side surface support portion of the side plate member 80 is equal. The distance W32 between the outer surfaces of the side plate members 82 and 82 and the distance W12 between the outer surfaces of the side surface support portions 62 and 62 of the top plate member 60 are equal, and the protrusion height H3 of the side surface support portions 82 and 82 of the side plate member 80 is equal to each other. The protrusion heights H1 of the side support portions 62 and 62 of the top plate member 60 are equal to each other, and the sum of the width U of the top plate member 60 and the width S of the side plate member 80 is equal to the width L of the bottom plate member 70. Since the pair of end plates 20 and 20 are fixed to the side support portions 82 and 82 of the 80, in order to enable the bus bar connection work between the electrode terminals 10b and 10b of the battery cell 10 after fixing the top plate member 60. Even when the top plate member 60 is arranged only between the electrode terminals 10b and 10b of the battery cell 10, by combining with the side plate member 80, the top plate member 60 side and the bottom plate member 70 side of the battery cell 10 are evenly compressed. This makes it possible to prevent local deformation of the battery cell 10. Further, after the top plate member 60, the bottom plate member 70, and the side plate member 80 are integrally extruded and molded, each member 60, 70, 80 can be separately formed, the productivity becomes better, and the cost of the battery pack 1 becomes higher. Can be further reduced.

In particular, the top plate member 60, the bottom plate member 70, and the side plate member 80 having the same dimensions as described above are integrally extruded and molded using the same material, and then the members 60, 70, and 80 are separately formed. , Can be easily formed. A method for manufacturing such a battery pack 1 will be described below.

[Battery pack manufacturing method]
FIG. 7 is a diagram illustrating a method for manufacturing a battery pack according to an embodiment of the present invention. FIG. 7 shows the exterior body member 100 immediately after the top plate member 60, the bottom plate member 70, and the side plate member 80 described above are integrally extruded and molded. The exterior body member 100 is formed by extruding along the D2 direction. The exterior body member 100 integrally includes an upper wall portion 101 corresponding to the upper surface, side surfaces, and bottom surfaces of a plurality of stacked battery cells 10, a lower wall portion 102, and a pair of side wall portions 103, 103. There is. Further, the lower wall portion 102 integrally includes a pair of overhanging portions 104, 104.

The upper wall portion 101 is a portion corresponding to the top plate portion 61 of the top plate member 60 and the side plate portion 81 of the side plate member 80. The length of the upper wall portion 101 along the D1 direction is equal to the length of the top plate portion 61 of the top plate member 60 and the side plate portion 81 of the side plate member 80 along the D1 direction. Further, the width of the upper wall portion 101 along the D2 direction is approximately the sum (U + S + S) of the width U of the top plate member 60 shown in FIG. 6 and the widths S and S of the two side plate members 80 and 80, respectively. equal.

The lower wall portion 102 is a portion corresponding to the bottom plate portion 71 of the bottom plate member 70. The lower wall portion 102 is formed in parallel with the upper wall portion 101. The length of the lower wall portion 102 along the D1 direction is substantially equal to the length of the bottom plate portion 71 of the bottom plate member 70 along the D1 direction. Further, the width of the lower wall portion 102 along the D2 direction is substantially equal to the width L of the bottom plate member 70 shown in FIG.

The pair of side wall portions 103, 103 are portions corresponding to the side support portions 62, 72, 82 of the top plate member 60, the bottom plate member 70, and the side plate member 80. The side wall portion 103 is perpendicular to the upper wall portion 101 and the lower wall portion 102. The width of the side wall portion 103 along the D2 direction is substantially equal to the sum (U + S + S) of the width U of the top plate member 60 shown in FIG. 6 and the widths S and S of the two side plate members 80 and 80, respectively. The height of the side wall portion 103 along the D3 direction is the protrusion height H1 of the side surface support portion 62 of the top plate member 60 shown in FIG. 3 and the protrusion of the side surface support portion 72 of the bottom plate member 70 shown in FIG. It is almost equal to the sum of height H2 (H1 + H2).

The pair of overhanging portions 104, 104 are portions corresponding to the mounting portions 73, 73 of the bottom plate member 70. The overhanging portion 104 extends in parallel with the lower wall portion 102 on both sides of the lower wall portion 102 along the D1 direction. The width of the overhanging portion 104 along the direction D2 is substantially equal to the width of the bottom plate portion 71 of the bottom plate member 70 shown in FIG. 6 along the D2 direction, and is substantially equal to the width L of the bottom plate member 70.

Since the exterior body member 100 is extruded along the direction D2, the thickness of each of the upper wall portion 101, the lower wall portion 102, the pair of side wall portions 103, 103, and the overhanging portions 104, 104 is D2. It is continuously uniform along the direction. The space 105 surrounded by the upper wall portion 101, the lower wall portion 102, and the pair of side wall portions 103, 103 is continuous with the same width and the same height along the D2 direction. Therefore, the cross-sectional shape when the exterior body member 100 is cut along the D1 direction is exactly the same regardless of the position of the exterior body member 100 cut in the D2 direction.

After the exterior body member 100 is extruded in this way, as shown in FIG. 8, the exterior body member 100 is cut along the cutting lines CL1 and CL1 along the extrusion direction. The cutting line CL1 is a cutting line that cuts a substantially central portion of the side wall portion 103 in the height direction along the extrusion direction (direction D2). The cutting lines CL1 and CL1 are formed in parallel with the upper wall portion 101 and the lower wall portion 102. As a result, the exterior body member 100 is divided into upper and lower parts.

The upper wall portion 101 of the two divided members has side wall portions 103 and 103 having substantially half the height at both ends, respectively. The member on the upper wall portion 101 side is a member corresponding to the top plate member 60 of the exterior body shown in FIG. The member on the upper wall portion 101 side shown in the present embodiment includes the pair of side plate members 80, 80 of the exterior body shown in FIG. 6 in addition to the top plate member 60.

The lower wall portion 102 of the two divided members has side wall portions 103 and 103 having substantially half the height at both ends, respectively. As shown in FIG. 6, the member on the lower wall portion 102 side after the division is the bottom plate member 70 having a width L.

Next, the member on the upper wall portion 101 side divided from the lower wall portion 102 side by the cutting lines CL1 and CL1 is further cut along the cutting lines CL2 and CL2 as shown in FIG. The cutting line CL2 is a cutting line along the D1 direction orthogonal to the extrusion direction (D2 direction). The cutting lines CL2 and CL2 are formed in parallel along the D1 direction. The positions of the cutting lines CL2 and CL2 from both ends in the D2 direction in the exterior body member 100 are the same. As a result, from the member on the upper wall portion 101 side of the exterior body member 100, as shown in FIG. 6, the top plate member 60 having the width U and the two side plate members 80 and 80 having the widths S and S, respectively. Is obtained.

The top plate member 60, the bottom plate member 70, and the side plate member 80 thus obtained are mounted on a plurality of stacked battery cells 10 as shown in FIG. 2 after the required number of bolt holes are formed. To. That is, a plurality of battery cells 10 sandwiched between the pair of end plates 20 and 20 are arranged between the side surface support portions 62 and 62 of the top plate member 60 and the side surface support portions 72 and 72 of the bottom plate member 70. Further, a plurality of battery cells 10 sandwiched between the pair of end plates 20 and 20 are arranged between the side surface support portions 82 and 82 of the side plate member 80. Then, as shown in FIGS. 1 and 2, the respective side surface support portions 62, 72, 82 are fixed to the end plate 20 by the bolts 63, 74, 84. As a result, the battery pack 1 in which the upper surface, the side surface, and the bottom surface of the plurality of stacked battery cells 10 are surrounded by the exterior body (top plate member 60, bottom plate member 70, and side plate member 80) can be obtained.

According to the manufacturing method of the battery pack 1, since the top plate member 60 and the bottom plate member 70 are integrally extruded and then separately formed, the dimensions of the top plate member 60 and the bottom plate member 70 can be made uniform. The dimensional difference between the top plate member 60 and the bottom plate member 70 is reduced. Therefore, the structural reliability of the battery pack 1 can be improved, and a uniform compressive force can be easily applied to the plurality of stacked battery cells 10. Further, since the top plate member 60 and the bottom plate member 70 are integrally processed, the manufacturing cost is also reduced.

Further, in the present embodiment, all the dimensions of the top plate member 60, the bottom plate member 70, and the side plate member 80 can be made uniform, and the dimensional difference between the top plate member 60, the bottom plate member 70, and the side plate member 80 is reduced. be able to. Therefore, the structural reliability of the battery pack 1 can be further improved, and a uniform compressive force can be easily applied to the plurality of stacked battery cells 10. Further, since the side plate member 80 is integrally processed with the top plate member 60 and then divided, the excess portion of the member can be reduced and the manufacturing cost can be further reduced.

Further, in the present embodiment, the mounting portion 73 for mounting the battery pack 1 to the mounting target portion is also integrally molded with the bottom plate member 70 during extrusion molding, so that the structure for mounting the battery pack 1 to the mounting target portion is easy. Can be formed into.

1 Battery pack 10 Battery cell 20 End plate 60 Top plate member 62 Side support part 70 Bottom plate member 72 Side support part 73 Mounting part 80 Side plate member 82 Side support part 100 Exterior member 103 Side wall part

Claims (6)

A method for manufacturing a battery pack in which a plurality of battery cells are laminated between a pair of end plates, and the pair of end plates and the plurality of battery cells are compressed and sandwiched by a plurality of exterior bodies.
An exterior body member having a shape extending over the upper surface, side surfaces, and bottom surface of the laminated structure including the pair of end plates and the plurality of battery cells laminated between the pair of end plates was integrally extruded and molded. Later, the side wall portion of the exterior body member corresponding to the side surface is cut along the extrusion direction, and the exterior body member is divided into a top plate member and a bottom plate member having side surface support portions at both ends. Form and
Next, the pair of end plates and the plurality of battery cells are arranged between the side surface support portions at both ends of the top plate member and the bottom plate member, and the top plate member and the bottom plate member are respectively arranged. A method for manufacturing a battery pack, in which the pair of end plates are fixed to the side surface support portion. The top plate member separately formed from the exterior body member is cut over a certain width along a direction intersecting the extrusion direction of the exterior body member to form a side plate member having side support portions at both ends. Further divided and formed
Next, the pair of end plates and the plurality of battery cells are arranged between the side surface support portions at both ends of the top plate member, the bottom plate member, and the side plate member, and the top plate member and the bottom plate are arranged. The method for manufacturing a battery pack according to claim 1, wherein the pair of end plates are fixed to the side support portions of the member and the side plate member, respectively. The method for manufacturing a battery pack according to claim 1 or 2, wherein when the exterior body member is extruded, the mounting portions projecting to both outer sides of the side surface support portion of the bottom plate member are simultaneously and integrally extruded. A battery pack in which a plurality of battery cells are laminated between a pair of end plates, and the pair of end plates and the plurality of battery cells are compressed and sandwiched by a plurality of exterior bodies.
The exterior body includes a top plate member and a bottom plate member.
The top plate member and the bottom plate member each have side support portions corresponding to the pair of end plates at both ends.
The distance between the inner surfaces of the side surface support portions of the top plate member is equal to the distance between the inner surfaces of the side surface support portions of the bottom plate member, and the distance between the outer surfaces of the side surface support portions of the top plate member. And the distance between the outer surfaces of the side surface support portions of the bottom plate member are equal.
A battery pack in which the pair of end plates are fixed to the side surface support portions of the top plate member and the bottom plate member. The exterior body further includes a side plate member having side support portions corresponding to the pair of end plates at both ends.
The distance between the inner surfaces of the side surface support portions of the side plate member is equal to the distance between the inner surfaces of the side surface support portions of the top plate member, and the distance between the outer surfaces of the side surface support portions of the side plate member. , Is equal to the distance between the outer surfaces of the side surface supports of the top plate member,
The protruding height of the side surface support portion of the side plate member is equal to the protruding height of the side surface support portion of the top plate member.
The sum of the width of the top plate member and the width of the side plate member is equal to the width of the bottom plate member.
The battery pack according to claim 4, wherein the pair of end plates are fixed to the side surface support portion of the side plate member. The battery pack according to claim 4 or 5, wherein the mounting portion integrally projects on both outer sides of the side surface support portion of the bottom plate member.

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