Battery case

Abstract

To provide a battery case capable of ensuring sealing performance between an upper cover and a lower case while restraining an increase in size.SOLUTION: A battery case includes: a lower case having a first butting portion; a resin upper cover having a second butting portion 113 that butts against the first butting portion; a seal member; a plurality of fastening members 80; and a plate portion 40 disposed on an outer surface 113a of the second butting portion 113. The plate portion 40 includes a first plate 41 and a second plate 42. The first plate 41 has a first end portion 41b including a first butting portion 411 and a first retracted portion 413. The second plate 42 has a second end portion 42a including a second butting portion 421 and a second retracted portion 423. In a state where the first butting portion 411 and the second butting portion 421 are in abutment with each other, a notch portion 430 is formed by the first retracted portion 413 and the second retracted portion 423.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a battery case, and more particularly to a battery case used in a battery pack mounted on a vehicle. [Background technology]

[0002] As a battery case used in a conventional battery pack, Japanese Patent No. 5236210 (Patent Document 1) discloses a technology in which a resin upper cover is fastened to a lower case so as to cover a recessed accommodation portion of the lower case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5236210 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a resin upper cover is fastened with fastening members, there is a concern that the resin may be scraped off by the fastening members. When multiple fastening members are used, the fastening force varies between the fastening points, making it difficult to maintain a uniform seal between the upper cover and the lower case.

[0005] To avoid this, it is conceivable to place a plate between the upper cover and the portion of the fastening member that fastens the upper cover. However, if the through holes provided in the plate to allow the fastening member to pass through are round or elongated holes, the size of the plate and therefore the size of the battery pack will be large.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide a battery case that can ensure the sealing performance between the upper cover and lower case while preventing the size from increasing. [Means for solving the problem]

[0007] The power storage device according to the present disclosure includes a lower case having a first butt portion, a resin upper cover having a second butt portion, a seal member for sealing a gap between the lower case and the upper cover, and a plurality of fastening members for fastening the lower case and the upper cover. The first butt portion and the second butt portion are butted together so as to sandwich the seal member therebetween and fastened by the plurality of fastening members. The second butt portion has an inner surface facing the first butt portion and an outer surface facing the opposite side to the side where the first butt portion is located. Each of the plurality of fastening members includes an opposing portion opposing the outer surface. The power storage device further includes a plate portion disposed on the outer surface so as to be sandwiched between the opposing portion of each of the plurality of fastening members and the outer surface. The plate portion includes a first plate and a second plate adjacent to each other in an extension direction of the first butt portion. The first plate has a first end portion on one side in the extension direction. The second plate has a second end facing the first end. The first end has a first abutment portion that abuts against the second plate and a first recessed portion that recedes so as to move away from the second plate. The second end has a second abutment portion that abuts against the first abutment portion and a second recessed portion that recedes so as to move away from the first plate. When the first abutment portion and the second abutment portion abut against each other, the first recessed portion and the second recessed portion form a notch through which one fastening member of the multiple fastening members can be inserted.

[0008] According to the above-mentioned configuration, the plate portion is disposed between the opposing portion of the fastening member and the outer surface of the upper cover. Therefore, when a resin upper cover is used, the upper cover can be prevented from being scraped by the fastening member. This prevents the fastening force from varying between the fastening points when the upper cover is fastened with a plurality of fastening members, which makes it difficult to maintain a substantially uniform seal between the upper cover and the lower case around the entire circumference.

[0009] In addition, the plate portion includes a first plate and a second plate, and by configuring the plate portion to butt against each other, once the position of one of the first plate and the second plate is determined, the plate portion can be easily positioned by butting the other plate against the first plate. Also, by forming a notch through which a fastening member can be inserted when the first plate and the second plate are butted against each other, the first plate and the second plate can be made smaller than a configuration in which the first plate and the second plate are provided with through holes such as round holes or elongated holes. This prevents the plate portion from becoming larger in size, and prevents the plate portion from protruding outward from the second butt portion. As a result, the size of the battery case can be prevented from becoming larger.

[0010] In the energy storage device based on the present disclosure, the cutout portion may have a U-shape that is recessed from the end side of the plate portion where the storage space surrounded by the upper cover and the lower case is located toward the side opposite to the side where the storage space is located.

[0011] According to the above configuration, the portions of the first plate and the second plate positioned around the cutout portion can be sandwiched approximately evenly between the opposing portions of the fastening member.

[0012] In the power storage device according to the present disclosure, the second butt portion may have a frame shape having a plurality of corners and a plurality of straight portions. The plate portion may have a frame-like annular shape corresponding to the second butt portion. The first plate may have a substantially L-shape along the corners, and the second plate may be provided in a straight line.

[0013] According to the above configuration, the first plate can be easily positioned by disposing the first plate at the corner portion, and the second plate can also be easily positioned by abutting the second plate against the positioned first plate.

[0014] In the power storage device according to the present disclosure, the upper cover may have a ceiling portion, a peripheral wall portion connected to the peripheral edge of the ceiling portion, a flange portion connected to a lower end of the peripheral wall portion and projecting outward from the peripheral edge of the ceiling portion when viewed from above and below, and a connection portion connecting the lower end of the peripheral wall portion and the flange portion. The second abutting portion may be constituted by the flange portion. The connection portion may have a curved shape that curves toward the flange portion as it extends downward. The first plate and the second plate may be disposed on the flange portion so as not to be located on the connection portion.

[0015] According to the above configuration, the first plate and the second plate do not ride up on the curved connection portion, so that the postures of the first plate and the second plate can be prevented from being distorted. This allows the first plate and the second plate to be sandwiched approximately evenly between the opposing portions of the multiple fastening members.

[0016] In the power storage device according to the present disclosure, the first abutment portion may have a fitted portion, and the second abutment portion may have a fitting portion that fits into the fitted portion.

[0017] According to the above configuration, the fitting portion is fitted into the fitted portion, whereby the second plate can be easily positioned. Effect of the Invention

[0018] According to the present disclosure, it is possible to provide a battery case that can ensure sealing between the upper cover and the lower case while preventing the size from increasing. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic exploded perspective view of a battery pack according to a first embodiment. [Diagram 2] 3 is a plan view showing the fastening structure between the upper cover and the lower case in the battery case pertaining to embodiment 1. FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. [Figure 4] 3 is an enlarged view of a portion surrounded by line IV in FIG. 2. FIG. [Diagram 5] FIG. 11 is a schematic exploded perspective view of a battery pack according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference characters in the drawings, and the description thereof will not be repeated.

[0021] (Embodiment 1) Fig. 1 is a schematic exploded perspective view of a battery pack according to embodiment 1. With reference to Fig. 1, a battery pack 1 according to embodiment 1 will be described.

[0022] The battery pack 1 according to the first embodiment is mounted, for example, on a hybrid vehicle capable of running using at least one of the power of a motor and an engine, or an electric vehicle running using driving force obtained from electric energy. The battery pack 1 is installed under a floor panel of the vehicle. Note that, when the battery pack 1 is mounted on the vehicle, the upper surface of the battery pack 1 may function as a floor panel.

[0023] 1, the battery pack 1 includes a battery case 10 and a plurality of battery modules 20. The battery case 10 accommodates the plurality of battery modules 20 therein. The battery case 10 includes an upper cover 11 and a lower case 12.

[0024] The lower case 12 has a generally box-like shape that opens upward. The lower case 12 may be made of a metal material such as an aluminum alloy, or may be made of a resin or the like.

[0025] The lower case 12 has a bottom wall portion 121, a peripheral wall portion 122, a first butt portion 123, and a pair of walls 124, 125. The peripheral wall portion 122 is provided so as to stand up from the periphery of the bottom wall portion 121. The first butt portion 123 is provided so as to include an upper end surface of the peripheral wall portion 122 and to protrude outward from the peripheral wall portion 122 when viewed in the up-down direction. The first butt portion 123 has an annular shape.

[0026] The pair of walls 124, 125 are provided inside the first abutting portion 123 so as to face the ends 20a, 20b of the battery module 20.

[0027] The upper cover 11 has a generally box-like shape that opens downward. The upper cover 11 is made of a resin material.

[0028] The upper cover 11 has a top plate portion 111, a peripheral wall portion 112, and a second butt portion 113. The peripheral wall portion 112 is provided so as to extend downward from the peripheral edge of the top plate portion 111. The second butt portion 113 functions as a flange portion that protrudes outward from the peripheral edge of the top plate portion 111 when viewed from the top-bottom direction.

[0029] The upper cover 11 and the lower case 12 are fastened by a plurality of fastening members 80 (see FIG. 2) with the first butt portion 123 and the second butt portion 113 butted together. With the first butt portion 123 and the second butt portion 113 butted together, a pair of walls 124, 125 are disposed inside the peripheral wall portion 112.

[0030] The detailed fastening structure between upper cover 11 and lower case 12 will be described later with reference to FIGS.

[0031] The multiple battery modules 20 are arranged side by side in a first direction (DR1 direction). The first direction is, for example, a direction parallel to the front-rear direction of the vehicle when the battery pack 1 is mounted on the vehicle. In the present embodiment, a case where two battery modules 20 are arranged is illustrated, but the number of battery modules 20 is not limited to two, and may be one, or three or more.

[0032] Each of the battery modules 20 includes a plurality of unit cells (not shown) arranged in a second direction (DR2 direction) perpendicular to the first direction. The second direction is, for example, a direction parallel to the width direction of the vehicle in the mounted state. The unit cells may be arranged in the first direction, or may be arranged in a matrix in the first and second directions.

[0033] The unit cell is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The power storage cell 21 has, for example, a rectangular shape. The secondary battery may use a liquid electrolyte or a solid electrolyte.

[0034] Fig. 2 is a plan view showing the fastening structure between the upper cover and the lower case in the battery case according to embodiment 1. Fig. 3 is a cross-sectional view taken along line III-III shown in Fig. 2. Fig. 4 is an enlarged view of a portion surrounded by line IV shown in Fig. 2. The fastening structure between the upper cover 11 and the lower case 12 will be described with reference to Figs. 2 to 4.

[0035] As shown in FIGS. 2 and 3, the battery case 10 includes a plate portion 40, a seal member 50, and a plurality of fastening members 80.

[0036] The seal member 50 seals the gap between the upper cover 11 and the lower case 12. The seal member 50 has an annular shape. For example, an elastic rubber member or the like can be used as the seal member 50.

[0037] The second butt portion 113 of the upper cover 11 has a shape that extends in an annular shape. Specifically, the second butt portion 113 has a frame shape having a plurality of corner portions 115 and a plurality of straight portions 116. More specifically, the second butt portion 113 has four corner portions 115 of a substantially L-shape and four straight portions 116. The four corner portions 115 and the four straight portions 116 are positioned alternately in the circumferential direction.

[0038] The second butt portion 113 has an inner surface 113a facing the first butt portion 123 side, and an outer surface 113b facing the opposite side to the side where the first butt portion 123 is located.

[0039] The plate portion 40 is disposed on the outer surface 113b of the second abutting portion 113. The plate portion 40 is sandwiched between the outer surface 113b and a facing portion 81 of each of the multiple fastening members 80. The facing portion 81 is a portion of the fastening member 80 that faces the outer surface 113b. The facing portion 81 is provided so as to expand in the radial direction from the core portion 83 of the fastening member 80.

[0040] The plate portion 40 has a frame-like annular shape corresponding to the shape of the second butt portion 113. The plate portion 40 includes a plurality of first plates 41 and a plurality of second plates 42. The first plates 41 and the second plates 42 are adjacent to each other in the extending direction of the second butt portion 113. That is, the plurality of first plates 41 and the plurality of second plates 42 are arranged alternately in the circumferential direction along the second butt portion 113.

[0041] The first plate 41 has a generally L-shape along the corner 115. The first plate 41 is disposed on the corner 115 of the second abutting portion 113. The second plate 42 is provided in a straight line. The second plate 42 is disposed on the straight line portion 116 of the second abutting portion 113.

[0042] The upper cover 11 has a connection portion 114 that connects the second abutting portion 113 and the peripheral wall portion 112. The connection portion 114 is curved toward the second abutting portion 113 as it extends downward.

[0043] The first plate 41 and the second plate 42 are disposed on the second abutting portion 113 so as not to be located on the connecting portion 114 .

[0044] Each first plate 41 has two ends 41a, 41b in the extending direction. The end 41b (first end) is located on one side in the extending direction. The end 41a (third end) is located on the other side in the extending direction.

[0045] Each second plate 42 has two ends 42a, 42b in the extending direction. The end 42a (second end) is located on the other side in the extending direction. The end 42a faces the end 41b (first end) of the adjacent first plate 41 on the other side in the extending direction.

[0046] The end 42b (fourth end) is located on one side in the extending direction. The end 42b faces the end 41a (third end) of the adjacent first plate 41 on one side in the extending direction.

[0047] As shown in FIG. 4, the end 41b has a first abutment portion 411 and a first recessed portion 413. The first abutment portion 411 abuts against the second plate 42 on one side in the extension direction. Specifically, the first abutment portion 411 abuts against a part of the end 42a (a second abutment portion 421 described later). The first recessed portion 413 is recessed from the second plate 42. Specifically, the first recessed portion 413 is recessed from the end 42a to be recessed toward the other side in the extension direction.

[0048] The end 42a has a second abutting portion 421 and a second recessed portion 423. The second abutting portion 421 abuts against the first abutting portion 411. The second recessed portion 423 is recessed from the first plate 41. Specifically, the second recessed portion 423 is recessed from the end 41b to one side in the extension direction.

[0049] When first abutment portion 411 and second abutment portion 421 are in abutting state, first recessed portion 413 and second recessed portion 423 form notch 430 into which fastening member 80 (more specifically, core portion 83) can be inserted. Specifically, notch 430 is formed by connecting edges of first recessed portion 413 and second recessed portion 423. Notch 430 has a U-shape recessed from end portion 40a of plate portion 40, where an accommodation space surrounded by upper cover 11 and lower case 12 is located, toward the opposite side to the side where the accommodation space is located.

[0050] Moreover, the first abutment portion 411 has a fitted portion 412. The fitted portion 412 is provided, for example, so as to be concave on the other side in the extending direction. The second abutment portion 421 has a fitting portion 422. The fitting portion 422 is provided, for example, so as to be convex on the other side in the extending direction. The first abutment portion 411 and the second abutment portion 421 abut against each other in a state in which the fitted portion 412 is fitted into the fitting portion 422.

[0051] In the above, the abutment structure between the first plate 41 and the second plate 42 on the end 41b side of the first plate 41 has been described, but the abutment structure between the first plate 41 and the second plate 42 on the end 41a side of the first plate 41 has the same configuration. That is, the end 41a of the first plate 41 has an abutment portion (third abutment portion) substantially similar to the first abutment portion 411 of the end 41b, and a recessed portion (third recessed portion) substantially similar to the first recessed portion 413. Similarly, the end 42b of the second plate 42 has an abutment portion (fourth abutment portion) substantially similar to the second abutment portion 421 of the end 42a, and a recessed portion (fourth recessed portion) substantially similar to the second recessed portion 423. In this case, the third recessed portion and the fourth recessed portion form a notch portion similar to the above, and the third abutment portion and the fourth abutment portion are provided with a fitted portion and a fitting portion, respectively.

[0052] When arranging the first plate 41 and the second plate 42, for example, the first plate 41 is first arranged at a corner. The first plate 41 has a substantially L-shape, which makes positioning easy. The first plate 41 has a plurality of cutouts along the extending direction. The shape of the cutouts is substantially the same as the shape of the cutout 430, and has, for example, a U-shape.

[0053] The first plate 41 is placed on the second abutting portion 113 so that each of the multiple cutouts overlaps with the insertion points of the multiple fastening members 80, and the first plate 41 is temporarily fixed by the multiple fastening members 80. Next, the second plate 42 is abutted against the first plate 41 to position the second plate 42. In this manner, the first plate 41 and the second plate 42 are alternately positioned in this order to form the annular plate portion 40.

[0054] Alternatively, the annular plate portion 40 may be formed by arranging a plurality of first plates 41 at a corresponding plurality of corner portions 115 and arranging a second plate 42 between the first plates 41 adjacent to each other in the circumferential direction.

[0055] As described above, in the present embodiment, the plate portion 40 is disposed between the opposing portion 81 of the fastening member 80 and the outer surface 113b of the upper cover 11. Therefore, when a resin upper cover 11 is used, it is possible to prevent the upper cover 11 from being scraped by the fastening member 80. This makes it difficult to maintain the sealing performance between the upper cover 11 and the lower case 12 approximately uniform over the entire circumference when the upper cover is fastened using a plurality of fastening members 80, thereby preventing the fastening force from varying between the fastening points.

[0056] In addition, the plate portion 40 includes the first plate 41 and the second plate 42, and is structured to butt these together. Once the position of one of the first plate 41 and the second plate 42 is determined, the plate portion 40 can be easily positioned by butting the other against the first plate 41. When the first plate 41 and the second plate 42 are butted together, a notch 430 through which the fastening member 80 can be inserted is formed, so that the first plate 41 and the second plate 42 can be made smaller than a configuration in which the first plate 41 and the second plate 42 are provided with through holes such as round holes or elongated holes. This prevents the size of the plate portion 40 from becoming large, and prevents the plate portion 40 from protruding outward from the second butt portion 113. As a result, the size of the battery case 10 can be prevented from becoming large.

[0057] Furthermore, by making the cutout portion 430 U-shaped as described above, the first plate 41 and the second plate 42 in the portions located around the cutout portion 430 can be sandwiched approximately evenly by the opposing portions 81 of the fastening members. Also, by providing the first plate 41 and the second plate 42 with U-shaped cutout portions as described above in addition to the boundary portion between the first plate 41 and the second plate 42, the first plate 41 and the second plate 42 can be fastened by the multiple fastening members 80 approximately evenly in the extension direction (circumferential direction).

[0058] Moreover, by forming the first plate 41 into a substantially L-shape along the corner portion 115, the positioning of the first plate 41 can be easily performed. Furthermore, by forming the second plate 42 into a straight line shape along the straight line portion 116 and abutting the second plate 42 against the positioned first plate 41, the positioning of the second plate 42 can also be easily performed. Furthermore, by fitting the fitting portion 422 into the fitted portion 412, the positioning of the second plate 42 can be easily performed.

[0059] In addition, by arranging the first plate 41 and the second plate 42 on the second abutting portion 113 (flange portion) so that the first plate 41 and the second plate 42 do not ride up on the curved connecting portion 114, it is possible to prevent the postures of the first plate 41 and the second plate 42 from collapsing. This allows the first plate 41 and the second plate 42 to be sandwiched approximately evenly by the opposing portions 81 of the multiple fastening members 80.

[0060] (Embodiment 2) 5 is a schematic exploded perspective view of a battery pack according to embodiment 2. With reference to FIG. 5, a battery pack 1A according to embodiment 2 will be described.

[0061] As shown in FIG. 5, a battery pack 1A according to the second embodiment differs from the battery pack 1 according to the first embodiment mainly in the shape of the upper cover 11.

[0062] The upper cover 11 has a generally flat plate shape. The peripheral edge of the upper cover 11 is fastened to an upper end 126 of the peripheral wall 122 of the lower case 12 by a plurality of fastening members 80. In this case, the peripheral edge of the upper cover 11 functions as a first butting portion, and the upper end 126 functions as a second butting portion. In the lower case 12, the pair of walls 124, 125 as in the first embodiment can be omitted.

[0063] Although the fastening structure between the upper cover 11 and the lower case 12 is omitted in FIG. 5, the fastening structure is substantially similar to the fastening structure according to the first embodiment.

[0064] Even when configured in this manner, the battery case 10 according to the second embodiment can achieve substantially the same effects as the first embodiment.

[0065] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0066] 1, 1A battery pack, 10 battery case, 11 upper cover, 12 lower case, 20 battery module, 20a, 20b end, 21 storage cell, 40 plate portion, 40a end, 41 first plate, 41a, 41b end, 42 second plate, 42a, 42b both ends, 50 seal member, 80 fastening member, 81 opposing portion, 111 top plate portion, 112 peripheral wall portion, 113 second abutting portion, 113a inner surface, 113b outer surface, 114 connection portion, 115 corner portion, 116 straight portion, 121 bottom wall portion, 122 peripheral wall portion, 123 first abutting portion, 124, 125 wall portion, 126 upper end portion, 411 first abutting portion, 412 fitted portion, 413 first recessed portion, 421 A second abutment portion, 422 a fitting portion, 423 a second recess portion, and 430 a notch portion.

Claims

1. a lower case having a first abutment portion; an upper cover made of resin and having a second abutting portion; a seal member that seals a gap between the lower case and the upper cover; a plurality of fastening members that fasten the lower case and the upper cover together, the first butted portion and the second butted portion are butted against each other so as to sandwich the seal member therebetween and are fastened by the plurality of fastening members, The second butt portion has an inner surface facing the first butt portion and an outer surface facing the opposite side to the side where the first butt portion is located, Each of the plurality of fastening members includes an opposing portion that faces the outer surface, a plate portion disposed on the outer surface so as to be sandwiched between the facing portion of each of the plurality of fastening members and the outer surface; the plate portion includes a first plate and a second plate adjacent to each other in an extending direction of the second butt portion, The first plate has a first end on one side in the extending direction, the second plate has a second end opposite the first end; the first end portion has a first abutting portion that abuts against the second plate and a first recessed portion that recedes so as to move away from the second plate, the second end portion has a second abutment portion that abuts against the first abutment portion and a second recessed portion that recedes so as to move away from the first plate, A battery case in which, when the first abutting portion and the second abutting portion abut against each other, the first recessed portion and the second recessed portion form a cutout portion through which one of the multiple fastening members can be inserted.

2. The battery case according to claim 1 , wherein the cutout portion has a U-shape recessed from the end side of the plate portion where the storage space surrounded by the upper cover and the lower case is located toward the opposite side to the side where the storage space is located.

3. The second abutting portion has a frame shape having a plurality of corner portions and a plurality of straight portions, The plate portion has a frame-like annular shape corresponding to the second abutment portion, The first plate has an L-shape along the corner portion, The battery case according to claim 1 , wherein the second plate is provided in a straight line.

4. the upper cover has a top plate portion, a peripheral wall portion connected to a peripheral edge of the top plate portion, a flange portion connected to a lower end portion of the peripheral wall portion and protruding outward from the peripheral edge of the top plate portion when viewed from above and below, and a connection portion connecting the lower end portion of the peripheral wall portion and the flange portion, The second abutting portion is constituted by the flange portion, The connection portion is curved downward toward the flange portion, The battery case according to claim 1 , wherein the first plate and the second plate are disposed on the flange portion so as not to be located on the connection portion.

5. The first abutment portion has a fitted portion, The battery case according to claim 1 , wherein the second abutting portion has a fitting portion that fits into the fitted portion.

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