Electricity storage device

Abstract

The invention relates to a power storage device. The power storage device includes a power storage stack including a plurality of power storage cells, a lower case housing the power storage stack, an upper cover covering the power storage stack, an outer elastic body made of an elastic material and provided on an outer surface of the upper cover, and an inner elastic body made of an elastic material and provided on an inner surface of the upper cover. The inner elastic body has a spring constant greater than a spring constant of the outer elastic body.

Description

Technical Field

[0001] The present disclosure relates to a power storage device. Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 10-69893 discloses a battery pack including a case for accommodating batteries and a rubber sponge provided on the inner surface of an upper case of the case. Summary of the invention

[0003] When a power storage device such as that described in Japanese Patent Application Laid-Open No. 10-69893 is mounted on a vehicle, it is required to reduce vibration of the power storage device relative to the vehicle. In addition, when a downward load is input to the power storage device from above, the upper cover may contact the power storage stack.

[0004] An object of the present disclosure is to provide an electric storage device capable of suppressing both vibration of the electric storage device relative to a vehicle and contact of an upper cover with an electric storage stack.

[0005] The power storage device of one aspect of the present disclosure comprises: a power storage stack including a plurality of power storage units; a lower shell accommodating the power storage stack; an upper cover covering the power storage stack; an outer elastic body composed of an elastic material and arranged on the outer surface of the upper cover; and an inner elastic body composed of an elastic material and arranged on the inner surface of the upper cover, the inner elastic body having a spring constant greater than that of the outer elastic body.

[0006] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a perspective view schematically showing a power storage device in one embodiment of the present disclosure.

[0008] Figure 2 It is a schematic representation of Figure 1 The illustrated perspective view shows the power storage device with the upper cover removed.

[0009] Figure 3 yes Figure 1 Cross-sectional view at line III-III in FIG.

[0010] Figure 4 It is a perspective view schematically showing the outer elastic body and the inner elastic body.

[0011] Figure 5 This is a diagram schematically showing the CAE analysis results of the stress distribution generated in the outer elastic body when a uniform load acts on the upper surface of the outer elastic body.

[0012] Figure 6 It is a plan view schematically showing a modified example of the outer elastic body.

[0013] Figure 7 It is a plan view schematically showing a modified example of the outer elastic body.

[0014] Figure 8 It is a plan view schematically showing a modified example of the outer elastic body.

[0015] Fig. 9 It is a plan view schematically showing a modified example of the outer elastic body.

[0016] Fig.10 It is a perspective view schematically showing a modified example of the outer elastic body. DETAILED DESCRIPTION

[0017] The embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0018] Figure 1 This is a perspective view schematically showing a power storage device in one embodiment of the present disclosure.

[0019] Figure 2 yes Figure 1 An exploded perspective view of the power storage device shown. Figure 3 yes Figure 1 The power storage device 1 is mounted on the bottom 10 of the vehicle (see Figure 3 ).

[0020] like Figure 1 to Figure 3 As shown, the power storage device 1 includes at least one power storage stack 100 , a lower case 200 , an upper cover 300 , a plate member 400 , at least one outer elastic body 500 , and at least one inner elastic body 600 .

[0021] At least one power storage stack 100 includes a plurality of power storage stacks 100. In the present embodiment, the power storage device 1 includes six power storage stacks 100. However, the number of power storage stacks 100 is not limited to six.

[0022] Each power storage stack 100 includes a plurality of power storage cells 110 arranged in a first direction. As each power storage cell 110, for example, a lithium ion battery can be cited. In addition, each power storage cell 110 can also be composed of a full solid battery using a solid electrolyte. Figure 2As shown, each storage cell 110 is formed into a flat rectangular parallelepiped. The length of the storage cell 110 in the second direction orthogonal to both the first direction and the up-down direction is longer than the length of the storage cell 110 in the up-down direction. The plurality of storage stacks 100 are arranged at intervals in the first direction and at intervals in the second direction.

[0023] The lower case 200 accommodates the plurality of power storage stacks 100 . The lower case 200 is open upward. The lower case 200 includes a bottom wall 210 , a peripheral wall 220 , and a load transmission portion 230 .

[0024] The bottom wall 210 supports each power storage stack 100 . The bottom wall 210 may include a cooling plate in contact with the bottom of each power storage stack 100 .

[0025] The peripheral wall 220 stands from the peripheral edge of the bottom wall 210 . The peripheral wall 220 surrounds the plurality of power storage stacks 100 .

[0026] The load transfer part 230 transfers the load input downward to the upper cover 300 to the bottom wall 210. The load transfer part 230 stands from the bottom wall 210. Figure 2 As shown, the load transfer part 230 is disposed between a pair of storage stacks 100 adjacent to each other in the first direction. The load transfer part 230 partitions between the pair of storage stacks 100 adjacent to each other in the first direction. The load transfer part 230 is connected to the peripheral wall 220. In other words, the load transfer part 230 has the function of reinforcing the peripheral wall 220. Figure 3 As shown, the height of the load transfer portion 230 from the bottom wall 210 is set to be substantially the same as the height of the peripheral wall 220 from the bottom wall 210 .

[0027] The upper cover 300 covers the plurality of power storage stacks 100. The upper cover 300 opens downward. The upper cover 300 accommodates the power storage stacks 100 together with the lower shell 200. The peripheral edge of the upper cover 300 is fixed to the lower shell 200 by screws or the like. The upper cover 300 includes a top wall 310 disposed above the plurality of power storage stacks 100. The top wall 310 may be formed in a flat plate shape.

[0028] The plate member 400 presses the plurality of power storage stacks 100 toward the bottom wall 210. The plate member 400 may be formed in a flat plate shape. The plate member 400 is formed of a synthetic resin or the like. The plate member 400 is arranged so as to span the plurality of power storage stacks 100 and the load transmission unit 230. Figure 3 As shown, the peripheral edge of the plate member 400 is in contact with the upper surface of the peripheral wall 220 .

[0029] At least one outer elastic body 500 includes a plurality of outer elastic bodies 500. Each outer elastic body 500 is disposed on the outer surface of the upper cover 300. Each outer elastic body 500 is made of an elastic material such as polyurethane. Each outer elastic body 500 is formed into a flat rectangular parallelepiped shape. The plurality of outer elastic bodies 500 are arranged at intervals from each other. Figure 2 and Figure 3 As shown, each outer elastic body 500 is arranged at a position overlapping with the load transmission portion 230 in the up-down direction, that is, above the load transmission portion 230 .

[0030] At least one inner elastic body 600 includes a plurality of inner elastic bodies 600. Each inner elastic body 600 is disposed on the inner surface of the upper cover 300. Each inner elastic body 600 is made of an elastic material such as polyurethane. Each inner elastic body 600 is formed into a flat rectangular parallelepiped shape. Each inner elastic body 600 can also be formed into the same shape as the outer elastic body 500. The plurality of inner elastic bodies 600 are arranged at intervals from each other. Figure 2 and Figure 3 As shown, each inner elastic body 600 is arranged at a position overlapping with the outer elastic body 500 in the vertical direction. Each inner elastic body 600 is arranged above the load transmission part 230. In this embodiment, each inner elastic body 600 is sandwiched between the top wall 310 of the upper cover 300 and the plate member 400.

[0031] The spring constant [N / mm] of each inner elastic body 600 is greater than the spring constant [N / mm] of each outer elastic body 500. In addition, the "spring constant" includes a static spring constant and a dynamic spring constant. The method for measuring the static spring constant and the dynamic spring constant is based on JIS K 6385. That is, the spring constant is calculated based on the relationship between the load acting on each elastic body 500, 600 and the deflection of each elastic body 500, 600 at this time.

[0032] The hardness (type C) of each inner elastic body 600 is greater than the hardness (type C) of each outer elastic body 500. The hardness (type C) is measured in accordance with JIS K 7312. That is, the hardness is calculated based on the reaction force acting on the pressing needle from the test piece when the test piece of each elastic body 500, 600 is pressed by the pressing needle.

[0033] like Figure 3 As shown, the thickness t6 of each inner elastic body 600 is greater than the thickness t5 of each outer elastic body 500. However, the thickness t6 of each inner elastic body 600 may be less than the thickness t5 of each outer elastic body 500.

[0034] One of the outer elastic body 500 and the inner elastic body 600 has an identification element that can be identified (distinguished) from the other of the outer elastic body 500 and the inner elastic body 600. In this embodiment, the outer elastic body 500 has an identification element 510 (see Figure 3 and Figure 4 ). However, the inner elastic body 600 may also have an identification element. Figure 1 and Figure 2 In the figure, the identification element 510 is omitted.

[0035] like Figure 3 and Figure 4 As shown, the identification element 510 is formed by a cutout. When viewed from above, the outer elastic body 500 has a long side 501 and a short side 502, and the cutout is formed in the center of the long side 501. The cutout has a shape that is concave toward the inside in a direction parallel to the short side 502. Figure 4 As shown, the inner elastic body 600 also has a long side 601 and a short side 602. Figure 5 Provide explanation.

[0036] Figure 5 FIG. 1 schematically shows the CAE analysis result of the stress distribution generated in the outer elastic body 500 when a uniform load is applied to the upper surface of the outer elastic body 500 . Figure 5 The figure shows that the highest stress is generated in region A, and the stress gradually decreases in the order of region A, region B, region C, region D, and region E. Figure 5 As shown in FIG. 1 , the stress generated in the center of the long side 501 is relatively small. Therefore, it can be seen that even if a cutout is formed in the center of the long side 501, the buffering function of the outer elastic body 500 is substantially maintained. Figure 4 As shown, a cutout serving as an identification element 510 is formed in the center of the long side 501 .

[0037] As described above, in the power storage device 1 of the present embodiment, the outer elastic body 500 is provided on the outer surface of the upper cover 300, so that when the power storage device 1 is mounted on the bottom 10 of the vehicle, the vibration of the power storage device 1 relative to the vehicle is effectively suppressed. In addition, the inner elastic body 600 having a large spring constant is provided on the inner surface of the upper cover 300, so that when a downward external force acts on the top wall 310 of the upper cover 300, the collision between the top wall 310 and the power storage stack 100 is suppressed.

[0038] Since the outer elastic body 500 has the identification element 510 , it is easy to distinguish the outer elastic body 500 from the inner elastic body 600 . This prevents the outer elastic body 500 and the inner elastic body 600 from being misplaced when assembling the power storage device 1 .

[0039] In addition, the form of the identification element 510 is not limited to the example of the above embodiment, and various changes can be made. Figure 6 to Figure 10 , a variation example of the identification element 510 is described.

[0040] like Figure 6 As shown, the identification element 510 may also be formed in a shape that is curved in a convex manner.

[0041] like Figure 7 As shown, the identification element 510 may also be formed at a corner of the outer elastic body 500 .

[0042] like Figure 8 As shown, the identification element 510 may be formed by a display portion connected to the surface of the outer elastic body 500. Alternatively, the identification element 510 may be formed by a through hole formed in the center of the outer elastic body 500.

[0043] like Fig. 9 As shown, the identification element 510 may also be composed of a color different from the color of the inner elastic body 600. Fig. 9 In FIG. 1 , the color of the surface of the outer elastic body 500 is different from the color of the surface of the inner elastic body 600 by oblique lines.

[0044] like Fig.10 As shown, when the outer elastic body 500 and the inner elastic body 600 are overlapped, the outer elastic body 500 has a protrusion protruding from the inner elastic body 600 in a plan view, and the identification element 510 may also be composed of the protrusion.

[0045] Those skilled in the art can understand that the above-mentioned exemplary embodiments are specific examples of the following technical solutions.

[0046] [Technical solution 1]

[0047] A power storage device comprising:

[0048] A power storage stack including a plurality of power storage units;

[0049] A lower shell for accommodating the power storage stack;

[0050] An upper cover covering the electricity storage stack;

[0051] an outer elastic body, made of elastic material and disposed on the outer surface of the upper cover; and

[0052] The inner elastic body is made of elastic material and is arranged on the inner surface of the upper cover.

[0053] The inner elastic body has a spring constant greater than a spring constant of the outer elastic body.

[0054] In the power storage device, an outer elastic body with a relatively small spring constant is provided on the outer surface of the upper cover, so that the vibration of the power storage device relative to the vehicle when the power storage device is mounted on the vehicle is effectively suppressed, and an inner elastic body with a relatively large spring constant is provided on the inner surface of the upper cover, so that the collision between the upper cover and the power storage stack when a downward external force acts on the upper cover is suppressed.

[0055] [Technical Solution 2]

[0056] According to the power storage device described in technical solution 1,

[0057] One of the outer elastic body and the inner elastic body has an identification element that can be identified with respect to the other of the outer elastic body and the inner elastic body.

[0058] In this aspect, one elastic body can be distinguished from the other elastic body, and thus, incorrect placement of the outer elastic body and the inner elastic body during assembly of the power storage device is suppressed.

[0059] [Technical Solution 3]

[0060] According to the power storage device described in technical solution 2,

[0061] The outer elastic body and the inner elastic body are each formed into a rectangular parallelepiped shape having a long side and a short side in a plan view.

[0062] The identification element is constituted by a cutout formed in the center of the long side portion of the one elastic body.

[0063] In this technical solution, identification can be performed while substantially maintaining the buffering properties.

[0064] [Technical Solution 4]

[0065] According to the power storage device described in technical solution 2,

[0066] The identification element is formed of a color different from a color of the other elastic body.

[0067] [Technical Solution 5]

[0068] According to the power storage device described in technical solution 2,

[0069] The outer elastic body and the inner elastic body are each formed into a rectangular parallelepiped shape having a long side and a short side in a plan view.

[0070] When the outer elastic body and the inner elastic body are overlapped, the one elastic body has a protrusion protruding from the other elastic body in a plan view,

[0071] The identification element is constituted by the protrusion.

[0072] [Technical Solution 6]

[0073] According to the power storage device described in technical solution 1,

[0074] The inner elastic body is arranged at a position overlapping with the outer elastic body in the up-down direction.

[0075] [Technical Solution 7]

[0076] According to the power storage device described in technical solution 6,

[0077] The lower housing has:

[0078] a bottom wall; and

[0079] The load transfer part transfers the load input downward to the upper cover to the bottom wall,

[0080] The load transmission portion stands upright from the bottom wall and is arranged on the side of the power storage stack.

[0081] The inner elastic body is arranged above the load transmitting portion.

[0082] In this aspect, since the load input downward to the upper cover is received by the bottom wall via the inner elastic body and the load transmission portion, damage to the electricity storage stack due to the load is suppressed.

[0083] [Technical Solution 8]

[0084] According to the power storage device described in technical solution 7,

[0085] further comprising a plate member that presses the electricity storage stack toward the bottom wall,

[0086] The plate member is arranged so as to straddle the power storage stack and the load transmission unit.

[0087] The inner elastic body is sandwiched between the upper cover and the plate member.

[0088] In this technical solution, the load input downward to the upper cover is more effectively transferred to the bottom wall.

[0089] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power storage device comprising: A power storage stack including a plurality of power storage units; A lower shell for accommodating the power storage stack; An upper cover covering the electricity storage stack; an outer elastic body, made of elastic material and disposed on the outer surface of the upper cover; and The inner elastic body is made of elastic material and is arranged on the inner surface of the upper cover. The inner elastic body has a spring constant greater than a spring constant of the outer elastic body.

2. The power storage device according to claim 1, One of the outer elastic body and the inner elastic body has an identification element that can be identified with respect to the other of the outer elastic body and the inner elastic body.

3. The power storage device according to claim 2, The outer elastic body and the inner elastic body are each formed into a rectangular parallelepiped shape having a long side and a short side in a plan view. The identification element is constituted by a cutout formed in the center of the long side portion of the one elastic body.

4. The power storage device according to claim 2, The identification element is composed of a color different from a color of the other elastic body.

5. The power storage device according to claim 2, The outer elastic body and the inner elastic body are each formed into a rectangular parallelepiped shape having a long side and a short side in a plan view. The one elastic body has a protrusion protruding from the other elastic body in a plan view when the outer elastic body and the inner elastic body are overlapped. The identification element is constituted by the protrusion.

6. The power storage device according to claim 1, The inner elastic body is arranged at a position overlapping with the outer elastic body in the up-down direction.

7. The power storage device according to claim 6, The lower housing has: a bottom wall; and The load transfer part transfers the load input downward to the upper cover to the bottom wall, The load transmission portion stands upright from the bottom wall and is disposed on a side of the power storage stack, and the inner elastic body is disposed above the load transmission portion.

8. The power storage device according to claim 7, further comprising a plate member for pressing the electricity storage stack toward the bottom wall, The plate member is arranged so as to straddle the power storage stack and the load transmission unit. The inner elastic body is sandwiched between the upper cover and the plate member.

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