JP7535871B2 - Battery case - Google Patents

Description

The present invention relates to a battery case.

Patent Document 1 discloses a battery case for housing a battery. This battery case includes a battery tray for placing the battery and a battery cover for covering the battery.

JP 2011-124101 A

A flange portion is formed on the periphery of the battery tray, and a cover-side flange portion is formed on the periphery of the battery cover. The battery tray and battery cover are fixed by screwing nuts onto bolts that pass through the flange portion and the cover-side flange portion and tightening them. If a gasket is sandwiched between the flange portion of the battery tray and the cover-side flange portion of the battery cover, the inside of the battery case can be waterproofed. In this case, in order to ensure the reliability of the waterproof function, it is necessary to increase the number of fastening points using bolts and nuts, which creates the problem of a large number of parts.

The present invention was developed based on the above circumstances, and aims to reduce the number of parts.

The battery case of the present invention comprises:
a lower case having a lower flange formed on an outer circumferential edge thereof and on which a battery module is mounted;
an upper cover having an upper flange portion formed on an outer circumferential edge portion and covering the battery module;
a gasket disposed between the lower flange portion and the upper flange portion,
a claw portion is integrally formed with at least one of the lower flange portion and the upper flange portion,
The other flange portion is sandwiched between the one flange portion and the claw portion.

By sandwiching one flange portion between the other flange portion and the claw portion, the gap between the lower flange portion and the upper flange portion is sealed liquid-tight by the gasket. Because the claw portion is formed integrally with one of the flange portions, the number of parts can be reduced compared to when fastening members such as bolts and nuts are used.

FIG. 1 is a perspective view of a battery case according to a first embodiment of the present invention; FIG. 1 is a perspective view of an upper cover before being attached to a lower case A perspective view showing the battery module and gasket attached to the lower case. Partially enlarged cross-sectional view showing the assembled state of the upper flange and lower flange FIG. 11 is a partially enlarged cross-sectional view showing an assembled state of an upper flange portion and a lower flange portion in the second embodiment; FIG. 11 is a partially enlarged cross-sectional view showing an assembled state of an upper flange portion and a lower flange portion according to a third embodiment of the present invention; FIG. 13 is a partially enlarged cross-sectional view showing an assembled state of an upper flange portion and a lower flange portion according to a fourth embodiment of the present invention;

In the present invention, a stepped bend may be formed in at least one of the lower flange and the upper flange. With this configuration, the stepped bend increases the moment of inertia of the flange, thereby improving the bending rigidity of the flange.

In the present invention, the lower flange portion may be formed with a positioning portion for positioning the gasket in the horizontal direction. With this configuration, the gasket can be positioned when placed on the lower flange portion, so that the gasket can be reliably attached between the lower flange portion and the upper flange portion.

In the present invention, the positioning portion may be formed by bending the lower flange portion into a stepped shape. With this configuration, the stepped bending of the lower flange portion increases the moment of inertia of the lower flange portion, thereby improving the bending rigidity of the lower flange portion.

Example 1
A first embodiment of the present invention will now be described with reference to Figures 1 to 4. In the following description, the up and down directions will be defined as the directions shown in Figures 1 to 4.

The battery case A of this embodiment 1 contains a battery module M therein to form a battery pack P. The battery case A includes a metal lower case 10 that is substantially horizontal and dish-shaped and has a substantially rectangular shape in plan view, a metal upper cover 20 that is attached to the lower case 10 so as to cover its upper surface, and a gasket 29. The interior space of the lower case 10 is a shallow storage space S (see FIG. 4) whose entire upper surface is open upward.

The lower case 10 is a single part having a horizontal bottom wall portion 11 that is rectangular in plan view, a lower peripheral wall portion 12, and a lower flange portion 13. The lower peripheral wall portion 12 rises upward from the outer periphery of the bottom wall portion 11 all around. The lower flange portion 13 protrudes outward from the upper edge of the lower peripheral wall portion 12 all around. As shown in FIG. 4, the lower flange portion 13 has a mounting portion 14, a rising portion 15, and a clamped portion 16.

The mounting portion 14 is directly connected to the upper edge of the lower peripheral wall portion 12 and extends horizontally outward around the entire circumference. The rising portion 15 rises diagonally upwards around the entire circumference from the outer periphery of the mounting portion 14. The clamped portion 16 extends horizontally outward around the entire circumference from the upper edge of the rising portion 15. The mounting portion 14, the rising portion 15, and the clamped portion 16 form a stepped lower bent portion 17 and also form a positioning portion 18.

The upper cover 20 is a single part having a horizontal upper wall portion 21 having a rectangular shape in a plan view, an upper peripheral wall portion 22, and an upper flange portion 23. The upper peripheral wall portion 22 extends downward from the outer periphery of the upper wall portion 21 all around. The upper flange portion 23 protrudes from the lower edge of the upper peripheral wall portion 22 all around to the outer periphery. The upper flange portion 23 has a pressing portion 24, a downward protruding portion 25, a clamping portion 26, and a plurality of claw portions 27. The pressing portion 24 is directly connected to the lower edge of the upper peripheral wall portion 22 and protrudes horizontally to the outer periphery all around. The downward protruding portion 25 protrudes downward from the outer periphery of the pressing portion 24 all around. The clamping portion 26 extends horizontally from the lower edge of the downward protruding portion 25 all the way around toward the outer periphery. The pressing portion 24, the downward protruding portion 25, and the clamping portion 26 form a stepped upper bend portion 28.

The multiple claws 27 protrude in a cantilever shape from multiple locations on the outer periphery of the clamping portion 26 that are spaced apart in the circumferential direction. Before the upper cover 20 and the lower case 10 are assembled, the multiple claws 27 protrude downward from the outer periphery of the clamping portion 26. Each claw 27 can be bent inward.

Next, the procedure for assembling the lower case 10, upper cover 20, and gasket 29 will be described. First, the gasket 29 is attached to the mounting portion 14 of the lower flange portion 13 of the lower case 10. The gasket 29 placed on the mounting portion 14 is surrounded by the rising portion 15 all around, so there is no risk of it shifting horizontally. After the gasket 29 is set on the lower flange portion 13, the battery module M is placed on the bottom wall portion 11 and fixed to the lower case 10 with fastening members (not shown) such as bolts and nuts.

Then, the upper cover 20 is placed over the battery module M, and the upper flange portion 23 is placed over the lower flange portion 13. At this time, the pressing portion 24 of the upper cover 20 is placed on the upper surface of the gasket 29. Here, the height dimension of the gasket 29 in a free state in which the gasket 29 is not elastically deformed is set to be larger than the combined dimension of the height difference between the placement portion 14 and the clamped portion 16 and the height difference between the pressing portion 24 and the clamped portion 26. With the pressing portion 24 placed on the gasket 29 in the free state, a gap is created between the upper surface of the clamped portion 16 and the lower surface of the clamped portion 26.

After that, the upper cover 20 is pressed down until the clamping portion 26 comes into surface contact with the upper surface of the clamped portion 16, and the gasket 29 is elastically deformed so as to be crushed between the placement portion 14 and the pressing portion 24. Then, while maintaining this state, the downward claw portion 27 is bent inwardly to be plastically deformed and brought into close contact with the lower surface of the clamped portion 16. The clamped portion 16 is clamped in the vertical direction between the claw portion 27 and the clamping portion 26 at multiple points spaced apart in the circumferential direction, and the lower case 10 and the upper cover 20 are fixed in a combined state. The upper surface of the lower flange portion 13 and the lower surface of the upper flange portion 23 are liquid-tightly sealed all around by the gasket 29 elastically deformed vertically. In this manner, the battery case A is manufactured with the battery module M accommodated in the accommodation space S.

The battery case A of this embodiment 1 includes a lower case 10, an upper cover 20, and a gasket 29. A lower flange portion 13 is formed on the outer peripheral edge of the lower case 10. A battery module M is placed on the bottom wall portion 11 of the lower case 10. An upper flange portion 23 is formed on the outer peripheral edge of the upper cover 20. The upper cover 20 is assembled to the lower case 10 so as to cover the battery module M. The gasket 29 is arranged in an elastically deformed state between the lower flange portion 13 and the upper flange portion 23, and provides waterproofing within the storage space S.

The upper flange portion 23 has a plurality of claws 27 formed integrally therewith. The lower flange portion 13 is sandwiched between the upper flange portion 23 and the plurality of claws 27. This sandwiching creates a liquid-tight seal in the gap between the lower flange portion 13 and the upper flange portion 23 with the gasket 29. The claws 27 are not separate parts from the upper cover 20, but are formed integrally with the upper cover 20. Therefore, compared to using fastening members such as bolts and nuts, the battery case A of this embodiment 1 can reduce the number of parts.

A stepped lower side bent portion 17 is formed in the lower side flange portion 13. By forming the lower side bent portion 17, the second moment of area of the lower side flange portion 13 is increased, and therefore the bending rigidity of the lower side flange portion 13 is increased. A stepped upper side bent portion 28 is also formed in the upper side flange portion 23. By forming the upper side bent portion 28, the second moment of area of the upper side flange portion 23 is increased, and therefore the bending rigidity of the upper side flange portion 23 is increased.

The lower flange portion 13 is formed with a positioning portion 18 that positions the gasket 29 in the horizontal direction, so that the gasket 29 can be positioned when placed on the lower flange portion 13. This allows the gasket 29 to be securely attached between the lower flange portion 13 and the upper flange portion 23. The positioning portion 18 is formed by bending the lower flange portion 13 into a step shape, and also functions as the lower bent portion 17. In other words, the lower bent portion 17 also functions as the positioning portion 18.

Example 2
Next, a second embodiment of the present invention will be described with reference to Fig. 5. In a battery case B of the second embodiment, the upper flange portion 33 of the upper cover 30 has a different configuration from that of the first embodiment. As the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations, and a description of the structure, operation, and effects will be omitted.

The upper flange portion 33 protrudes from the lower edge of the upper peripheral wall portion 32 to the outer periphery around the entire circumference. The upper flange portion 33 has a flange main body portion 34 and a plurality of claw portions 37. The flange main body portion 34 is a flat, horizontal plate with no steps over the entire area. The inner peripheral area of the flange main body portion 34 is directly connected to the lower edge of the upper peripheral wall portion 32 and functions as a pressing portion 35. The outer peripheral area of the flange main body portion 34 beyond the pressing portion 35 functions as a clamping portion 36.

The multiple claws 37 protrude in a cantilever shape from multiple locations on the outer periphery of the clamping portion 36 that are spaced apart in the circumferential direction. Before the upper cover 30 and the lower case 10 are assembled, the multiple claws 37 protrude downward from the outer periphery of the clamping portion 36. Each claw 37 can be bent inward.

When the lower case 10, upper cover 30, and gasket 29 are assembled, the clamping portion 36 comes into face-to-face contact with the upper surface of the clamped portion 16, the gasket 29 placed on the mounting portion 14 elastically deforms so as to be crushed vertically between the mounting portion 14 and the pressing portion 35, and the claw portion 37 plastically deforms by bending and adheres closely to the lower surface of the clamped portion 16. The clamped portion 16 is clamped vertically between the claw portion 37 and the clamping portion 36, so that the lower case 10 and the upper cover 30 are fixed in a combined state. The upper surface of the lower flange portion 13 and the lower surface of the upper flange portion 33 are sealed liquid-tight all around by the gasket 29, which has elastically deformed vertically.

Example 3
Next, a third embodiment of the present invention will be described with reference to Fig. 6. In a battery case C of the third embodiment, the lower flange portion 43 of the lower case 40 and the upper flange portion 53 of the upper cover 50 have configurations different from those of the first embodiment. As the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations, and descriptions of the structures, functions, and effects will be omitted.

The lower flange portion 43 protrudes from the upper edge of the lower peripheral wall portion 42 to the outer periphery around the entire circumference. The lower flange portion 43 has a pressure-receiving portion 44, a support portion 45, a mounting portion 46, and a clamped portion 47. The pressure-receiving portion 44 is directly connected to the upper edge of the lower peripheral wall portion 42 and protrudes horizontally to the outer periphery around the entire circumference. The support portion 45 protrudes downward from the outer periphery of the pressure-receiving portion 44 around the entire circumference. The mounting portion 46 protrudes horizontally to the outer periphery around the lower edge of the support portion 45. The clamped portion 47 rises upward in a wall-like shape around the entire circumference from the outer periphery of the mounting portion 46. The pressure-receiving portion 44, the support portion 45, the placement portion 46, and the clamped portion 47 form a stepped lower-side bent portion 48 and also form a groove-shaped positioning portion 49.

The upper flange portion 53 extends from the lower edge of the upper peripheral wall portion 52 to the outer periphery. The upper flange portion 53 has a flange main body portion 54 and a plurality of claw portions 57. The flange main body portion 54 is a flat, horizontal plate with no steps over the entire area. The outer peripheral area of the flange main body portion 54 functions as a pressing portion 55. The inner peripheral area of the flange main body portion 54 relative to the clamping portion functions as an abutment portion 56 that is directly connected to the lower edge of the upper peripheral wall portion 52.

The multiple claws 57 protrude in a cantilever shape from multiple locations of the pressing portion 55 that are spaced apart in the circumferential direction. Before the upper cover 50 and the lower case 40 are assembled, the multiple claws 57 protrude downward from the outer periphery of the pressing portion 55. Each claw 57 can be bent inward.

When the lower case 40, the upper cover 50, and the gasket 29 are assembled, the abutment portion 56 abuts against the upper surface of the pressure receiving portion 44, the outer periphery of the pressing portion 55 abuts against the upper end surface of the clamped portion 47, and the gasket 29 placed on the mounting portion 46 is elastically deformed so as to be crushed vertically between the mounting portion 46 and the pressing portion 55. The claw portion 57 is plastically deformed by bending and adheres closely to the lower surface of the mounting portion 46. The clamped portion 47 is clamped vertically between the claw portion 57 and the outer periphery of the pressing portion 55, so that the lower case 40 and the upper cover 50 are fixed in a combined state. The upper surface of the lower flange portion 43 and the lower surface of the upper flange portion 53 are sealed liquid-tight all around by the gasket 29, which is elastically deformed vertically.

Example 4
Next, a fourth embodiment of the present invention will be described with reference to Fig. 7. In the battery case D of the fourth embodiment, the upper flange portion 63 of the upper cover 60 has a different configuration from that of the first embodiment. As the other configurations are the same as those of the first embodiment, the same reference numerals are used for the same configurations, and descriptions of the structures, functions, and effects will be omitted.

The upper flange portion 63 is in a form that protrudes from the lower end edge of the upper peripheral wall portion 62 to the outer periphery side all around. The upper flange portion 63 has a pressing portion 64, an upward protruding portion 65, a clamping portion 66, and a plurality of claw portions 67. The pressing portion 64 is directly connected to the lower end edge of the upper peripheral wall portion 62 and is in a form that protrudes horizontally to the outer periphery side all around. The upward protruding portion 65 is in a form that protrudes diagonally upward to the outer periphery side all around from the outer periphery edge of the pressing portion 64. The clamping portion 66 is in a form that protrudes horizontally to the outer periphery side all around from the upper end edge of the upward protruding portion 65. The pressing portion 64, the upward protruding portion 65, and the clamping portion 66 form a stepped upper bent portion 68.

When the lower case 10, upper cover 60, and gasket 29 are assembled, the clamping portion 66 comes into face-to-face contact with the upper surface of the clamped portion 16, the gasket 29 placed on the mounting portion 14 elastically deforms so as to be crushed vertically between the mounting portion 14 and the pressing portion 64, and the claw portion 67 plastically deforms by bending and adheres closely to the lower surface of the clamped portion 16. The clamped portion 16 is clamped vertically between the claw portion 67 and the clamping portion 66, so that the lower case 10 and the upper cover 60 are fixed in a combined state. The upper surface of the lower flange portion 13 and the lower surface of the upper flange portion 63 are sealed liquid-tight all around by the gasket 29, which has elastically deformed vertically.

<Other Examples>
The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention.
In the above embodiments 1 to 4, the claw portions are formed only on the upper flange portion, but the claw portions may be formed only on the lower flange portion, or may be formed on both the upper and lower flange portions.

In the above first to fourth embodiments, the bent portion is formed in the lower flange portion, but the lower flange portion may have a shape that does not have a bent portion.
In the above embodiments 1 to 4, the positioning portion is formed by bending the lower flange portion into a stepped shape, but the positioning portion may also be a rib that is separate from the lower flange portion and fixed to the lower flange portion.

In the above embodiments 1 to 4, a positioning portion is formed on the lower flange portion, but the lower flange portion may have no positioning portion.

A, B, C, D... Battery case M... Battery module 10, 40... Lower case 13, 43... Lower flange portion 17, 48... Lower bent portion (bent portion)
18, 49... Positioning portion 20, 30, 50, 60... Upper cover 23, 33, 53, 63... Upper flange portion 27, 37, 57, 67... Claw portion 28, 68... Upper bent portion (bent portion)

Claims (4)

a metal lower case having a lower flange formed on an outer circumferential edge thereof and on which a battery module is mounted;
an upper cover made of metal and having an upper flange portion formed on an outer circumferential edge portion thereof, the upper cover covering the battery module;
a gasket disposed between the lower flange portion and the upper flange portion,
The lower flange portion and the upper flange portion have portions that protrude horizontally toward an outer periphery,
a claw portion extending in a cantilever manner toward an inner periphery from an outer periphery of a portion of the flange portion that protrudes horizontally toward the outer periphery is integrally formed with at least one of the lower flange portion and the upper flange portion;
A battery case in which a portion of the other of the lower flange portion and the upper flange portion that protrudes horizontally toward the outer periphery is clamped in the vertical direction between a portion of the one flange portion that protrudes horizontally toward the outer periphery and the claw portion . At least one of the lower flange portion and the upper flange portion has a first portion that protrudes horizontally toward an outer periphery, a second portion that extends upward or downward from the first portion, and a third portion that protrudes horizontally toward the outer periphery from the second portion,
The battery case according to claim 1 , wherein a stepped bent portion is formed by the first portion, the second portion, and the third portion . The battery case according to claim 1 or 2, wherein the lower flange portion is formed with a positioning portion for positioning the gasket in the horizontal direction. the lower flange portion has a mounting portion that protrudes horizontally from a lower peripheral wall portion that constitutes the lower case toward the outer periphery, a rising portion that rises upward from an outer periphery edge of the mounting portion, and a clamped portion that protrudes horizontally from an upper end edge of the rising portion toward the outer periphery,
The battery case according to claim 3 , wherein the positioning portion has a stepped shape bent by the placement portion, the rising portion, and the clamped portion.

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