Exterior case and electric power storage device

Abstract

This exterior case 1 comprises: a bottom portion 1A; a side portion 1B that is fastened to the bottom portion 1A and is provided with a flange 21 on an inner side above a lowermost end; a seal member 31 that is disposed between the upper surface of the bottom portion 1A and the lower surface of the flange 21; and fastening mechanisms 11a to 11d and 12a to 12d for fastening the bottom portion 1B and extension portions 11a and 12a, which are portions below the flange 21 of the side portion 1B, through an operation from the lateral direction in a state in which the seal member 21 is compressed in the vertical direction.

Description

Exterior Case and Power Storage Device

[0001] The present disclosure relates to an exterior case and a power storage device.

[0002] Patent Document 1 discloses a power storage device including a waterproof exterior case and a battery unit housed in the exterior case. Generally, this type of exterior case includes a bottom cover forming a bottom on which the battery unit is placed, a front cover, a rear cover, and a pair of side covers forming side portions, and a top cover forming a top.

[0003] Japanese Patent Application Laid-Open No. 2021-118043

[0004] In the above-described exterior case, when the sealing member that seals the gap between the side portion and the bottom portion is compressed in the vertical direction, if the side portion and the bottom portion are to be screwed from the back surface of the bottom portion, it is necessary to turn over the bottom portion on which the heavy battery unit is placed, resulting in poor workability.

[0005] An object of the present disclosure is to improve the workability of the operation of fastening the side portion to the bottom portion in an exterior case configured to compress a sealing member that seals the gap between the side portion and the bottom portion in the vertical direction.

[0006] One aspect of the present disclosure provides an exterior case including a bottom portion, a side portion fastened to the bottom portion and provided with a flange on the inner side above the lowermost end, a sealing member disposed between the upper surface of the bottom portion and the lower surface of the flange, and a fastening mechanism that fastens an extension portion, which is a portion of the side portion below the flange, and the bottom portion in a state where the sealing member is compressed in the vertical direction by an operation from the lateral direction.

[0007] According to the exterior case of the present disclosure, in a configuration in which a sealing member that seals the gap between the side portion and the bottom portion is compressed in the vertical direction, the workability of the operation of fastening the side portion to the bottom portion can be improved.

[0008] An exploded perspective view of an energy storage device equipped with an outer casing according to the first embodiment of this disclosure. A perspective view of the outer casing of the first embodiment. A bottom view of the top cover of the outer casing of the first embodiment. An exploded perspective view of a part of the outer casing of the first embodiment. A perspective view of the main cover in the first embodiment seen from below. A perspective view of the main cover in the first embodiment seen from above. An enlarged cross-sectional view of the outer casing of the first embodiment. An exploded perspective view of an energy storage device equipped with an outer casing according to the second embodiment of this disclosure. A perspective view of the outer casing of the second embodiment. A bottom view of the outer casing of the second embodiment. An enlarged perspective view of a part of the outer casing of the second embodiment. An enlarged perspective view of a part of the outer casing of the second embodiment (before screw tightening). An enlarged perspective view of a part of the outer casing of the second embodiment (after screw tightening). An enlarged perspective view of a part of the outer casing of the third embodiment. An enlarged perspective view of a part of the outer casing of the third embodiment (before screw tightening). An enlarged perspective view of a part of the outer casing of the third embodiment (after screw tightening). An exploded perspective view of an energy storage device equipped with an outer casing according to the fourth embodiment of this disclosure. Perspective view of the outer casing of the fourth embodiment. Bottom view of the outer casing of the fourth embodiment. Exploded perspective view of the outer casing of the fourth embodiment. Enlarged perspective view of a part of the outer casing of the fourth embodiment. Enlarged perspective view of a part of the outer casing of the fourth embodiment (before screw tightening). Enlarged perspective view of a part of the outer casing of the fourth embodiment (after screw tightening).

[0009] An exterior case according to one embodiment of the present disclosure comprises a bottom portion, a side portion fastened to the bottom portion and having a flange on the inside above the lowest end, a sealing member disposed between the upper surface of the bottom portion and the lower surface of the flange, and a fastening mechanism that fastens the extension portion, which is the portion of the side portion below the flange, to the bottom portion by operation from the side, with the sealing member compressed in the vertical direction.

[0010] The sealing member is compressed between the upper surface of the bottom and the lower surface of the flange. In other words, the sealing member is compressed in the vertical direction. The fastening mechanism fastens the side extension to the bottom by operating it from the side. Because the fastening mechanism fastens the side extension to the bottom by operating it from the side, there is no need to turn the bottom inside out, improving work efficiency.

[0011] The side portion comprises at least a first plate-like portion extending along one surface and a second plate-like portion extending along a surface different from the one surface and integrally connected to the first plate-like portion, and the flange and the sealing member may be provided to include the connecting portion between the first plate-like portion and the second plate-like portion.

[0012] The first and second plate-like portions on the side are integrally connected, and there is no gap at the connection point between them. Therefore, there is no need to provide a sealing member to seal the connection point between the first and second plate-like portions, which reduces the number of sealing members and simplifies the structure of the outer casing.

[0013] The aforementioned side portion may be a cylindrical shape with a single integrated structure.

[0014] By making the side section a single, integrated cylindrical structure, there are no gaps to seal on the side, which further reduces the number of sealing components and simplifies the construction of the outer casing.

[0015] The fastening mechanism may be configured to fasten the extension portion of the side portion below the flange to the bottom portion by screw fastening from the side.

[0016] The fastening mechanism may be configured such that when the screw for fastening is rotated in the tightening direction, the side portion descends toward the bottom portion.

[0017] The fastening mechanism may also include an extension of the side portion located on the outside of the side of the bottom portion so as to extend vertically, a bolt having a shaft portion with a male threaded portion formed thereon, and a head provided at one end of the shaft portion, a circular hole provided in the extension of the side portion through which the shaft portion of the bolt is inserted such that the head is located on the outside of the extension portion, an inclined portion provided in the bottom portion opposite to the circular hole and having an elongated hole through which the shaft portion inserted into the circular hole is inserted, and a nut element located on the opposite side of the inclined portion from the extension portion and having an inclined surface that slides with the inclined portion and a female threaded portion that screws into the male threaded portion of the bolt.

[0018] When the bolt is rotated in the tightening direction, the lateral distance between the bolt head and the nut element decreases. Since the bolt shaft is inserted through an elongated hole in the bottom, as the lateral distance between the bolt head and the nut element decreases, the bolt descends together with the nut element due to sliding between the inclined portion of the bottom and the inclined surface of the nut element. Since the bolt shaft is inserted through a circular hole in the extension of the side, as the bolt and nut element descend, the side descends relative to the bottom, and the sealing member is compressed between the lower surface of the flange and the upper surface of the bottom.

[0019] The nut element may include a nut member having the female thread portion and the inclined surface.

[0020] The nut element may comprise a circular hole through which the shaft portion of the bolt is inserted, an intermediate member provided with the inclined surface, and a nut provided with the female thread portion.

[0021] The fastening mechanism may include an extension of the side portion located on the outside of the side of the bottom portion so as to extend vertically, a screw having a shaft portion with a male threaded portion formed thereon, and a head provided at one end of the shaft portion, a first inclined portion provided on the extension of the side portion and having an elongated hole through which the shaft portion of the screw is inserted such that the head is located on the outside of the extension portion, and a second inclined portion provided on the bottom portion so as to be in slidable contact with the first inclined portion and having a female threaded hole that screws into the male threaded portion of the screw through which the shaft portion is inserted.

[0022] When the screw is rotated in the tightening direction, the lateral distance between the side extension and the bottom decreases. Since the screw shaft is inserted into an elongated hole in the extension, as the lateral distance between the side extension and the bottom decreases, the first inclined portion slides downward relative to the second inclined portion. As a result, the side portion descends relative to the bottom, and the sealing member is compressed between the lower surface of the flange and the upper surface of the bottom.

[0023] Other embodiments of the present disclosure include an external casing and a battery unit housed within the external casing.

[0024] The following describes specific examples of this disclosure in detail based on the drawings. In the following description, terms indicating specific directions or positions (e.g., "up," "down," and other terms including these) will be used as needed. The use of these terms is for the purpose of facilitating understanding of the disclosure with reference to the drawings, and the meaning of these terms does not limit the technical scope of this disclosure. Also, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components. Furthermore, the embodiments shown below are examples of the technical concept of this disclosure and do not limit this disclosure to them. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are intended to be illustrative, and not to limit the scope of this disclosure unless specifically stated. Also, the content described in one embodiment or example is applicable to other embodiments or examples. Furthermore, the size and positional relationships of the components shown in the drawings may be exaggerated for clarity in the explanation.

[0025] The exterior casing of this disclosure can be applied to a home energy storage system, as described, for example, with reference to the attached drawings. However, the exterior casing of this disclosure is not limited to home energy storage systems, and can be applied to other energy storage systems and various other electrical devices.

[0026] (First Embodiment) Referring to Figures 1 and 2, the energy storage device 2 comprising a waterproof outer case 1 according to the first embodiment of the present disclosure further comprises a battery unit 3 housed within the outer case 1. The battery unit 3 comprises a frame 3a and a plurality of battery cells 3b arranged in multiple stages on the frame 3a.

[0027] The outer casing 1 comprises a bottom cover 1A which forms the bottom on which the battery unit 3 is placed, a main cover 1B and a rear cover 1C which form the sides, and a top cover 1D which forms the top. A pair of legs 1E for fixing the battery unit 1 to the base are fixed to the underside of the bottom cover 1A with screws.

[0028] During the assembly of this energy storage device 2, the battery unit 3 is first placed on the top surface of the bottom cover 1A and secured with screws. Next, the main cover 1B is secured to the bottom cover 1A with screws, followed by the rear cover 1C being secured to the bottom cover 1A and the main cover 1B with screws. Finally, the top cover 1D is secured to the upper ends of the main cover 1B and the rear cover 1C with screws.

[0029] The gap between the bottom cover 1A and the main cover 1B is sealed by the compression of sealing members 31 and 32 between the bottom cover 1A and the main cover 1B, as will be described in detail later. Similarly, the gap between the rear cover 1C and the main cover 1B, and the gap between the rear cover 1C and the bottom cover 1A are sealed by the compression of sealing members (not shown). Furthermore, the gap between the top cover 1D and the main cover 1B and rear cover 1C is sealed by the compression of sealing member 33 (see Figure 3) between the lower surface of the top cover 1D and the upper surfaces of the main cover 1B and rear cover 1C. The sealing members are made of a material with elasticity, water resistance, and weather resistance, such as nitrile rubber.

[0030] Referring to Figures 4 to 6, the main cover 1B has a structure in which the front cover and a pair of side covers of a conventional waterproof outer case used in energy storage devices are integrally connected, and is generally U-shaped in plan view. Specifically, the main cover 1B comprises a front portion 11 (first plate-like portion) that extends along the front surface (one side) of the energy storage device 2, and a pair of side portions 12 (second plate-like portions) that extend along both sides (different sides) of the energy storage device 2. The front portion 11 and the side portions 12 are substantially made of a single sheet of metal, and both sides of the front portion 11 and the pair of side portions 12 are connected to each other at connection portions 13, which are bent portions of the sheet metal.

[0031] At the tip of each side portion 12, that is, the end opposite to the front portion 11, a bracket portion 14 is provided that is bent relative to the side portion 12. Both sides of the rear cover 1C are screwed to these bracket portions 14, and a sealing member (not shown) is compressed between the front surface of the bracket portion 14 and the rear surface of the rear cover 1C, thereby sealing the gap between the bracket portion 14 and the rear cover 1C.

[0032] As described above, the exterior case 1 of this embodiment has a structure in which the front portion 11 (front cover in conventional exterior cases) and the individual side portions 12 (side covers in conventional exterior cases) are integrally connected at the connection portion 13. Therefore, there is no gap at the connection portion that is unavoidable when the front portion 11 and the side portions 12 are separate parts. By making the connection portion 13 an integral structure without gaps, there is no need to provide a sealing member to seal the connection portion 13. As a result, the number of sealing members provided in the exterior case 1 can be reduced, and the structure of the exterior case 1 can be simplified.

[0033] Continuing to refer to Figures 4 to 6, the main cover 1B is provided with flanges 21 on the inside of each side above the lowest end. Specifically, each flange 21 comprises a first portion 21a that extends over the entire side portion 12, and a second portion 21b that extends from one end of the first portion 21a and terminates at a position close to the joint portion 13 of the front portion 11. Each flange 21 also comprises a third portion 21c that extends from the other end of the first portion 21a to the bracket portion 14. Furthermore, each flange 21 comprises a first tab portion 21d that protrudes from the first portion 21a along the inside of the side portion 12, a second tab portion 21e that protrudes from the second portion 21b along the inside of the front portion 11, and a third tab portion 21f that protrudes from the third portion 21c along the inside of the bracket portion 15. The first tab portion 21d is fixed to the side portion 12 by a bolt 21g, the second tab portion 21e is fixed to the front portion 11 by a bolt 21h, and the third tab portion 21f is fixed to the bracket portion 14 by a bolt 21i.

[0034] As is most clearly shown in Figure 4, the front portion 11, the pair of side portions 12, and the pair of bracket portions 14 of the main cover 1B each have extension portions 11a, 12a, and 14a that extend downward from the flange 21. The extension portions 11a, 12a, and 14a are each positioned to extend straight vertically outward from the side of the bottom cover 1A. Through holes 11b and 12b are provided in the extension portions 11a and 12a, respectively. The extension portions 11a and 12a are fastened to the sides of the bottom cover 1A by screws from the side. Specifically, the shafts of the screws 11c and 12c are inserted horizontally through the through holes 11b and 12b and screwed into the screw holes 11d and 12d of the bottom cover 1A. In this embodiment, the extensions 11a, 12a, through holes 11b, 12b, screws 11c, 12c, and screw holes 11d, 12d constitute a fastening mechanism for fastening the bottom cover 1A and the main cover 1B.

[0035] Referring also to Figure 7, a sealing member 31 is sandwiched between the upper surface of the bottom cover 1A and the lower surfaces of the pair of flanges 21 of the main cover 1B, and is compressed in the vertical direction. This vertically compressed sealing member 31 seals the gaps in the parts where the main cover 1B is fastened to the bottom cover 1A, near the pair of side portions 12, the pair of connecting portions 13, the pair of bracket portions 14, and the connecting portions 13 on both sides of the front portion 11 of the main cover 1B. In the pre-assembly state, the sealing member 31 may be attached to the lower surface of the flange 21 or to the upper surface of the bottom cover 1A.

[0036] The sealing member 31 has a shape that corresponds to the flange 21. That is, the sealing member 31 has a long first portion 31a and two shorter portions, the second portion 31b and the third portion 31c, which are bent at both ends of the first portion 31a, and these correspond to the first portion 21a, the second portion 21b and the third portion 21c of the flange 21, respectively.

[0037] In areas of the front section 11 other than the vicinity of the connection section 13, a sealing section 32 (schematically shown only in Figure 4), separate from the sealing member 31, is sandwiched between the inside of the extension section 11a of the front section 11 and the side of the bottom cover 1A, and is compressed laterally, thereby sealing the gap.

[0038] When fastening the main cover 1B to the bottom cover 1A (on which the heavy battery unit 3 is placed as described above), first the tips of the pair of side portions 12 are moved from the side towards the top of the bottom cover 1A (see arrow A1 in Figure 1), compressing the sealing member 32 between the inside of the front portion 11 and the side of the bottom cover 1A. Next, the main cover 1B is lowered towards the bottom cover 1A (see arrow A2 in Figure 1). This lowering compresses the seal 31 by sandwiching it between the lower surface of the flange 21 of the main cover 1B and the upper surface of the bottom cover 1A. With the sealing members 31 and 32 compressed in this way, the screws 11c, 12c, and 14c, which are inserted through the through holes 11b and 12b of the extension portions 11a and 12a of the main cover 1B, are screwed into the screw holes 11d, 12d, and 14d of the bottom cover 1A.

[0039] As described above, of the sealing members 31 and 32 that seal the gap at the fastening portion between the bottom cover 1A and the main cover 1B, the sealing member 31 is compressed vertically between the upper surface of the bottom cover 1A and the lower surface of the flange 21. On the other hand, the fastening of the bottom cover 1A and the main cover 1B is achieved by screwing the extensions 11a and 12b of the front portion 11 and side portion 12 of the main cover 1B to the sides of the bottom cover 1A with screws 11c and 12c from the side. In other words, the extensions 11a and 12b of the main cover 1B and the bottom cover 1A can be fastened by tightening the screws 11c and 12c from the side. Therefore, although the sealing member 31 is configured to be compressed vertically, there is no need to turn the bottom cover 1A inside out in order to fasten the main cover 1B to the bottom cover 1A, improving work efficiency.

[0040] (Second Embodiment) Referring to Figures 8 to 10, the energy storage device 52 equipped with a waterproof outer case 51 according to the second embodiment of the present disclosure further comprises a battery unit 53 (schematically shown) housed within the outer case 1.

[0041] The outer case 51 includes a bottom cover 51A that forms the bottom and a main cover 51B. A battery unit 53 is placed and fixed on the bottom cover 51A.

[0042] The main cover 51B has a bottomed cylindrical structure in which all of the covers other than the bottom cover in a conventional general waterproof outer case adopted for the power storage device, that is, the front cover, the rear cover, and a pair of side covers that form the sides, and the top cover that forms the top are integrally connected. Specifically, the main cover 51B includes a front portion 61, a rear portion 62, a pair of side portions 63, and a top portion 64 that extend along the front surface, the rear surface, a pair of both side surfaces, and the top surface of the power storage device 52, respectively. The front portion 61 and the pair of side portions 63 are connected to each other at a connection portion 65, and the rear portion 62 and the pair of side portions 63 are connected to each other at a connection portion 66. Further, the front portion 61, the rear portion 62, and the pair of side portions 63 are connected to the top portion 64 to each other at connection portions 67, 68, and 69, respectively. The connection portions 65 to 69 are formed by bending a sheet metal.

[0043] When assembling this power storage device 52, first, the battery unit 53 is placed on the upper surface of the bottom cover 51A and fixed by screwing. Then, the bottomed cylindrical main cover 51B is put on the bottom cover 51A and fixed by screwing.

[0044] As will be described in detail later, the gap at the portion where the bottom cover 51A and the main cover 51B are fastened is sealed by compressing a seal member 76 by the bottom cover 1A and the main cover 1B.

[0045] In this embodiment, the outer case 51 has all the covers except the bottom cover 51A, namely the front portion 61, rear portion 62, pair of side portions 63, and top portion 64, which correspond to the front cover, rear cover, pair of side covers, and top cover of a conventional outer case, respectively, all connected integrally at connection portions 65 to 69, thereby forming a bottomed cylindrical main cover 51B. As a result, the main cover 52 has no gaps that require sealing, so the number of sealing members provided in the outer case 1 can be further reduced, and the structure of the outer case 1 can be further simplified.

[0046] The main cover 51B is provided with an annular flange 71 on the inside above its lowest end. Specifically, the flange 71 is provided to encircle the inside of the lowest ends of the front portion 61, the rear portion 62, and the pair of side portions 63.

[0047] The front portion 61, rear portion 62, and pair of side portions 63 of the main cover 51B each have extension portions 61a, 62a, and 63a that extend straight downward from the flange 71. Multiple (five in this embodiment) circular holes 61b and 62b are provided horizontally through the extension portion 61a of the front portion 61 and the extension 62a of the rear portion 62, respectively. On the other hand, the side portion of the bottom cover 51A is provided with an inclined portion 73, which is recessed inward at the location opposite the circular holes 61b and 62b. In this embodiment, the inclination angle of both the inner and outer surfaces of the inclined portion 73 is 45 degrees. An elongated hole 73a extending in the direction of inclination is formed in the inclined portion 73.

[0048] As most clearly shown in FIG. 11, the extension parts 61a and 62a of the front part 61 and the rear part 62 of the main cover 51B are fastened to the bottom cover 51A by screwing the bolts 74 into the nut members 75 (nut elements in this embodiment) located on the opposite side of the extension parts 61a and 62a of the inclined part 73. The nut member 75 is provided with an inclined surface 75a slidable with the inner surface of the inclined part 73. Further, the nut member 75 is provided with an internal thread part 75b penetrating in the horizontal direction. The shaft part 74a (with a male thread part 74b formed) of the bolt 74 is horizontally inserted into the circular holes 61b and 62b so that the head part 74c provided at one end is located outside the extension parts 61a and 62a. The shaft part 74a is further screwed into the internal thread part 74b of the nut member 75. By being sandwiched between the head part 74c of the bolt 74 and the nut member 75, the main cover 52 (the extension parts 61a and 62a of the front part 61 and the rear part 62) and the bottom cover 51A (the inclined part 73) are fastened to each other. In this embodiment, the angle of the inclined surface 75a of the nut member 75 with respect to the axis of the bolt 74 is 45 degrees corresponding to the inclination angle of the inclined part 73. In this embodiment, the extension parts 61a and 62a of the front part 61 and the rear part 62, the circular holes 61b and 62b provided in the extension parts 61a and 62a, the inclined part 73 of the bottom cover 51A, the elongated hole 73a provided in the inclined part 73, the bolt 74, and the nut member 75 constitute a fastening mechanism.

[0049] An annular seal member 76 is sandwiched between the upper surface of the bottom cover 51A and the lower surface of the flange 71 (which is annular as described above) of the main cover 52 and is compressed in the vertical direction. The vertically compressed seal member 76 seals the gaps between the front part 61, the rear part 62, and the extension parts 61a, 62a, and 63a of the pair of side parts 63 of the main cover 51B and the bottom cover 51A. In the state before assembly, the seal member 76 may be attached to the lower surface of the flange 71 or may be attached to the upper surface of the bottom cover 51A.

[0050] The sealing member 76, which seals the gap between the bottom cover 51A and the main cover 51B, is compressed vertically between the upper surface of the bottom cover 51A and the lower surface of the flange 21. On the other hand, the fastening of the bottom cover 51A and the main cover 51B is achieved by screwing a bolt 74, which is inserted horizontally, into a nut member 75. In other words, the extensions 61a and 62a of the main cover 51B and the bottom cover 51A can be fastened by tightening the bolt 74 from the side. Therefore, although the sealing member 76 is compressed vertically, it is not necessary to turn the bottom cover 51A inside out to fasten the main cover 51B to the bottom cover 51A, improving work efficiency.

[0051] Figure 12 shows the state before tightening the bolt 74, with the shaft portion 74a of the bolt 74 inserted through the circular holes 61b, 62b and the elongated hole 73a, and the male threaded portion 74b of the shaft portion 74a of the nut member 75 slightly screwed into the female threaded portion 74b of the nut member 75. When the bolt 74 is rotated in the tightening direction from the state before tightening shown in Figure 12, the lateral distance between the head 74c of the bolt 74 and the nut member 75 decreases. Since the shaft portion 74a of the bolt 74 is inserted through the elongated hole 73a provided in the inclined portion 73 of the bottom cover 51A, as is clear from Figure 13, as the lateral distance between the head 74c of the bolt 74 and the nut member 75 decreases, the bolt 74 descends together with the nut member 75 due to the sliding of the inclined surface 75a of the nut member 75 against the inclined portion 73 of the bottom cover 51A. Since the shaft portion 74a of the bolt 74 is inserted through the circular holes 61b and 62b provided in the extensions 61a and 62a of the front portion 61 or rear portion 62 of the main cover 51B, as the bolt 74 and nut member 75 descend, the bottom cover 51A descends, and the sealing member 76 is compressed between the lower surface of the flange 71 and the upper surface of the bottom cover 51A. Thus, in this embodiment, when the bolt 74 for fastening the main cover 51B to the bottom cover 51A is tightened, the main cover 51B descends relative to the bottom cover 51A, and the sealing member 76 for sealing the gap between the bottom cover 51A and the main cover 51B can be compressed vertically. In other words, the fastening of the main cover 51B to the bottom cover 51A and the compression of the sealing member 76 can be performed simultaneously by simply tightening the bolt 74, further improving work efficiency.

[0052] (Third Embodiment) Figures 14 to 15B show a third embodiment of the present disclosure. This embodiment differs from the second embodiment only in that it employs a combination of an intermediate member 81 and a hexagonal nut 82, which is an example of a general nut, instead of the nut member 75 of the second embodiment (see, for example, Figure 11). In Figures 14 to 15B, elements that are the same as or similar to those in the second embodiment are denoted by the same reference numerals.

[0053] The intermediate member 81 is provided with an inclined surface 81a that can slide against the inner surface of the inclined portion 73 of the bottom cover 51A. The intermediate member 81 is also provided with a circular hole 81b that penetrates horizontally. In this embodiment, the angle of the circular hole 81b on the inclined surface 81a of the intermediate member 81 with respect to the axis is 45 degrees, which corresponds to the inclination angle of the inclined portion 73. The hexagonal nut 82 is positioned on the opposite side of the inclined surface 81a of the intermediate member 81. The head 74c of the bolt 74 is located on the outside of the extensions 61a and 62a of the main cover 51B, more specifically the front portion 61 or the rear portion 62. The shaft portion 74a of the bolt 74 (which has a male threaded portion 74b) is inserted through the circular holes 61b and 62b of the extension portions 61a and 62a, the elongated hole 73a of the inclined portion 73, and the circular hole 81b of the intermediate member 81, passing through the intermediate member 81 and screwed into the female threaded portion 82a of the hexagonal nut 82. In this embodiment, the extension portions 61a and 62a of the front portion 61 and the rear portion 62, the circular holes 61b and 62b provided in the extension portions 61a and 62a, the inclined portion 73 of the bottom cover 51A, the elongated hole 73a provided in the inclined portion 73, the bolt 74, the intermediate member 81, and the hexagonal nut 82 constitute the fastening mechanism. In addition, in this embodiment, the combination of the intermediate member 81 and the hexagonal nut 82 constitutes the nut element.

[0054] As is clear from Figures 15A and 15B, when the bolt 74 is rotated in the tightening direction, the lateral distance between the head 74c of the bolt 74 and the hexagonal nut 82 decreases, and the bolt 74 descends together with the nut member 75 due to the sliding of the inclined surface 81a of the intermediate member 81 against the inclined portion 73 of the bottom cover 51A. Therefore, when the bolt 74 is tightened to fasten the main cover 51B to the bottom cover 51A, the main cover 51B descends relative to the bottom cover 51A, and the sealing member 76 is compressed between the lower surface of the flange 71 and the upper surface of the bottom cover 51A.

[0055] (Fourth Embodiment) The fourth embodiment will be described with reference to Figures 16 to 21B. In these figures, elements that are the same as or similar to those in the second embodiment are denoted by the same reference numerals. This embodiment differs from the second embodiment only in the fastening mechanism.

[0056] As is most clearly shown in Figures 19 and 20, the extension 61a of the front portion 61 and the extension 62a of the rear portion 62 are each provided with a first inclined portion 91, which is recessed inward at multiple locations (five locations in this embodiment). Each first inclined portion 91 is provided with an elongated hole 91a extending in the direction of inclination. On the other hand, the side of the bottom cover 51A is provided with a second inclined portion 92, which is recessed inward at locations opposite to the elongated holes 91a. Each second inclined portion 92 is provided with a female screw hole 92a. The inclination angles of the first inclined portion 91 and the second inclined portion 92 are the same, and the inner surface of the first inclined portion 91 is in slidable contact with the outer surface of the second inclined portion 92. In this embodiment, the inclination angles of both the inner and outer surfaces of the first and second inclined portions 91 and 92 are 45 degrees.

[0057] The head 93a of the screw 93 is located on the outside of the main cover 51B, more specifically the extensions 61a and 62a of the front portion 61 or the rear portion 62. The shaft 93b of the screw 93 (on which the male thread portion 93c is formed) is inserted into the elongated hole 91a of the first inclined portion 91 of the main cover 51B in an inclined position corresponding to the inclination of the first inclined portion 91 (in this embodiment, an inclined position of 45 degrees), and is screwed into the female thread hole 92a of the second inclined portion 92 of the bottom cover 51A. The first inclined portion 91 is sandwiched between the head 93a of the screw 93 and the second inclined portion 92, thereby fastening the main cover 52 (the extensions 61a and 62a of the front portion 61 and the rear portion 62) and the bottom cover 51A together. In this embodiment, the fastening mechanism consists of a first inclined portion 91 provided on the extensions 61a and 62a of the front portion 61 and the rear portion 62, an elongated hole 91a provided on the first inclined portion 91, a second inclined portion 92 of the bottom cover 51A, a female screw hole 92a provided on the second inclined portion 92, and a screw 93.

[0058] Referring to Figure 20, similar to the second and third embodiments, an annular sealing member 76 is sandwiched between the upper surface of the bottom cover 51A and the lower surface of the annular flange 71 of the main cover 52 and compressed in the vertical direction, thereby sealing the gap between the main cover 51B and the bottom cover 51A.

[0059] Referring to Figures 21A and 21B, when the screw 93 is rotated in the tightening direction, the lateral distance between the first inclined portion 91 provided on the extensions 61a and 62a of the main cover 51B and the second inclined portion 92 of the bottom cover 51A decreases. Since the shaft portion 93b of the screw 93 is inserted through the elongated hole 91a provided in the first inclined portion 91, as the lateral distance between the first inclined portion 91 and the second inclined portion 92 decreases, the first inclined portion 91 slides downward relative to the second inclined portion 92. As a result, the main cover 51B descends relative to the bottom cover 51A, and the sealing member is compressed between the lower surface of the flange 71 and the upper surface of the bottom cover. In other words, the fastening of the main cover 51B to the bottom cover 51A and the compression of the sealing member 76 can be performed simultaneously by simply tightening the bolt 74.

[0060] This disclosure is not limited to the embodiments and various modifications are possible. For example, the form of the main cover is not limited to that of the embodiments, and may be an integrated structure of any two or more of the bottom cover, front cover, rear cover, pair of side covers, and top cover. Furthermore, the combination of a configuration in which a sealing member is compressed between the lower surface of a flange provided on the main cover and the upper surface of the bottom cover, and a configuration in which the main cover and bottom cover are fastened by operation from the side, can also be applied to front covers, rear covers, and side covers that are not integrated at all.

[0061] In the descriptions of each of the embodiments above, expressions such as parallel, perpendicular, orthogonal, identical, and equal include not only strictly parallel, perpendicular, orthogonal, identical, and equal, but also substantially parallel, perpendicular, orthogonal, identical, and equal.

[0062] This disclosure may include the following embodiments: (Embodiment 1) An exterior case comprising: a bottom portion; a side portion fastened to the bottom portion and having a flange on its inner side above the lowest end; a sealing member disposed between the upper surface of the bottom portion and the lower surface of the flange; and a fastening mechanism that fastens an extension portion, which is the portion of the side portion below the flange, to the bottom portion by operation from the side, with the sealing member compressed in the vertical direction. (Embodiment 2) The exterior case according to Embodiment 1, wherein the side portion comprises at least a first plate-like portion that extends along one surface and a second plate-like portion that extends along a surface different from the one surface and is integrally connected to the first plate-like portion, and the flange and the sealing member are provided to include the connecting portion between the first plate-like portion and the second plate-like portion. (Embodiment 3) The exterior case according to Embodiment 1 or 2, wherein the side portion is a cylindrical shape with an integral structure. (Aspect 4) The exterior case according to any one of aspects 1 to 3, wherein the fastening mechanism is configured to fasten the extension portion of the side portion below the flange to the bottom portion by screw fastening from the side. (Aspect 5) The exterior case according to aspect 4, wherein the fastening mechanism is configured such that when the screw for fastening is rotated in the tightening direction, the side portion descends toward the bottom portion. (Aspect 6) The exterior case according to aspect 5, wherein the fastening mechanism comprises: an extension of the side portion located on the outside of the side of the bottom portion so as to extend vertically; a bolt as a screw having a shaft portion on which a male thread is formed and a head provided at one end of the shaft portion; a circular hole provided in the extension of the side portion, through which the shaft portion of the bolt is inserted such that the head is located on the outside of the extension portion; an inclined portion provided in the bottom portion opposite to the circular hole, having an elongated hole through which the shaft portion inserted into the circular hole is inserted; and a nut element located on the opposite side of the inclined portion from the extension portion, having an inclined surface that slides with the inclined portion and a female thread portion that screws into the male thread portion of the bolt. (Aspect 7) The exterior case according to aspect 6, wherein the nut element comprises a nut member having the female thread portion and the inclined surface.(Aspect 8) The exterior case according to aspect 6, wherein the nut element comprises a circular hole through which the shaft portion of the bolt is inserted, an intermediate member provided with an inclined surface, and a nut provided with a female thread portion. (Aspect 9) The exterior case according to aspect 5, wherein the fastening mechanism comprises an extension portion of the side portion located on the outside of the side of the bottom portion so as to extend vertically, a screw having a shaft portion with a male thread portion formed thereon and a head provided at one end of the shaft portion, a first inclined portion provided on the extension portion of the side portion and having an elongated hole through which the shaft portion of the screw is inserted such that the head is located on the outside of the extension portion, and a second inclined portion provided on the bottom portion so as to slidably contact the first inclined portion and having a female thread hole that screws into the male thread portion of the screw through which the shaft portion is inserted in the elongated hole. (Aspect 10) An energy storage device comprising an exterior case according to any one of aspects 1 to 9 and a battery unit housed in the exterior case.

[0063] 1 Outer case 1A Bottom cover 1B Main cover 1C Rear cover 1D Top cover 1E Legs 2 Power storage device 3 Battery unit 3a Frame 3b Battery cell 11 Front part (first plate-shaped part) 11a Extension part 11b Through hole 11c Screw 11d Screw hole 12 Side part (second plate-shaped part) 12a Extension part 12b Through hole 12c Screw 12d Screw hole 13 Connection part 14 Bracket part 14a Extension part 21 Flange 21a First part 21b Second part 21c Third part 21d First tab part 21e Second tab part 21f Third tab part 21g, 21h, 21i Bolt 31 Seal member 31a First part 31b Second part 31c Third part 32, 33 Seal member 51 Outer case 51A Bottom cover 51B Main cover 52 Energy storage device 53 Battery unit 61 Front part 61a Extension part 61b Circular hole 62 Rear part 62a Extension part 62b Circular hole 63 Side part 63a Extension part 64 Top part 65, 66, 67, 68, 69 Connection part 71 Flange 73 Inclined part 73a Slotted hole 74 Bolt 74a Shaft part 74b Male thread part 74c Head 75 Nut member 75a Inclined surface 75b Female thread part 76 Seal member 81 Intermediate member 81a Inclined surface 81b Circular hole 82 Hexagonal nut 82a Female thread part 91 First inclined part 91a Slotted hole 92 Second inclined part 92a Female threaded hole 93 Thread 93a Head 93b Shaft 93c Male threaded portion 93c

Claims

1. An outer casing comprising: a bottom portion; a side portion fastened to the bottom portion and having a flange on its inner side above the lowest end; a sealing member positioned between the upper surface of the bottom portion and the lower surface of the flange; and a fastening mechanism that fastens an extension portion, which is the portion of the side portion below the flange, to the bottom portion by operation from the side, with the sealing member compressed in the vertical direction.

2. The exterior case according to claim 1, wherein the side portion comprises at least a first plate-shaped portion extending along one surface and a second plate-shaped portion extending along a surface different from the one surface and integrally connected to the first plate-shaped portion, and the flange and the sealing member are provided to include the connecting portion between the first plate-shaped portion and the second plate-shaped portion.

3. The outer case according to claim 2, wherein the side portion is a cylindrical structure with an integral structure.

4. The exterior case according to claim 2 or 3, wherein the fastening mechanism is configured to fasten the extension portion of the side portion below the flange to the bottom portion by screw fastening from the side.

5. The exterior case according to claim 4, wherein the fastening mechanism is configured such that when the screw for screw fastening is rotated in the tightening direction, the side portion descends toward the bottom portion.

6. The exterior case according to claim 5, wherein the fastening mechanism comprises: an extension of the side portion located on the outside of the side of the bottom portion so as to extend vertically; a bolt as a screw having a shaft portion on which a male thread is formed and a head provided at one end of the shaft portion; a circular hole provided in the extension of the side portion through which the shaft portion of the bolt is inserted such that the head is located on the outside of the extension portion; an inclined portion provided in the bottom portion opposite to the circular hole, having an elongated hole through which the shaft portion inserted into the circular hole is inserted; and a nut element located on the opposite side of the inclined portion from the extension portion, having an inclined surface that slides with the inclined portion and a female thread that screws into the male thread portion of the bolt.

7. The exterior case according to claim 6, wherein the nut element comprises a nut member having the female thread portion and the inclined surface.

8. The exterior case according to claim 6, wherein the nut element comprises a circular hole through which the shaft portion of the bolt is inserted, an intermediate member provided with an inclined surface, and a nut provided with a female threaded portion.

9. The exterior case according to claim 5, wherein the fastening mechanism comprises: an extension of the side portion located on the outside of the side of the bottom portion so as to extend vertically; a screw having a shaft portion on which a male thread is formed and a head provided at one end of the shaft portion; a first inclined portion provided on the extension of the side portion, having an elongated hole through which the shaft portion of the screw is inserted such that the head is located on the outside of the extension portion; and a second inclined portion provided on the bottom portion so as to slidably contact the first inclined portion, having a female screw hole that engages with the male thread portion of the screw through which the shaft portion is inserted.

10. An energy storage device comprising an outer case according to any one of claims 1 to 9, and a battery unit housed within the outer case.

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