Battery case and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-12489162-B2
Application number	US-202117905880-A
Country	US
Kind code	B2
Filing date	Feb 2, 2021
Priority date	Mar 12, 2020
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A battery case includes a mounting surface formed into a desired shape to place a sealing plate stably thereon. The battery case includes: an open box-shaped case body holding components of a battery; and a sealing plate that is integrated with the case body to close an opening of the case body. A stepped portion on which the sealing plate is placed is formed on an inner wall surface of the case body. The stepped portion includes: a mounting surface on which the sealing plate is placed; an opposed surface opposed to a periphery of the sealing plate placed on the mounting surface; and a depressed corner depressed outwardly from the opposed surface between the mounting surface and the opposed surface.

First claim

The invention claimed is:

1 . A battery case, comprising:
an open box-shaped case body holding components of a battery; a sealing plate that is integrated with the case body to close an opening of the case body; and a stepped portion on which the sealing plate is placed, and which is formed on an inner wall surface of the case body, wherein the stepped portion comprises a mounting surface on which the sealing plate is placed, an opposed surface opposed to a periphery of the sealing plate placed on the mounting surface, and a depressed corner depressed outwardly from the opposed surface between the mounting surface and the opposed surface.

2 . The battery case as claimed in claim 1 , wherein the depressed corner is formed such that a thickness of a side wall of the case body increases gradually from an outermost portion of the depressed corner toward the opposed surface.

3 . The battery case as claimed in claim 1 , wherein the depressed corner comprises: a first section leading from an outermost portion in the case body at a predetermined curvature; and a second section leading from the first section to the opposed surface while being inclined or curved at a curvature different from the predetermined curvature of the first section.

4 . A manufacturing method of a battery case, in which a stepped portion is formed on a predetermined portion of an inner wall surface of an open box-shaped case body by pushing the inner wall surface between the predetermined portion and an opening of the case body, and in which a sealing plate placed on the stepped portion is integrated with the case body, comprising:
forming a depressed corner and a mounting surface on which the sealing plate is placed by depressing the predetermined portion of the inner wall surface to a predetermined depth; and thereafter forming the stepped portion by pushing a portion of the inner wall surface closer to the opening than the depressed corner thereby reducing a thickness of a side wall of the case body at the pushed portion thinner than a thickness of a portion of the side wall opposite to the opening.

5 . The manufacturing method of the battery case as claimed in claim 4 , wherein the depressed corner is depressed deeper than the pushed portion of the inner wall surface closer to the opening than the depressed corner.

6 . The manufacturing method of the battery case as claimed in claim 4 , wherein the depressed corner and the mounting surface are formed by pushing the inner wall surface of the case body, using a punch having a bottom surface parallel to a bottom surface of the case body, and a leading edge having an acute angle protruding toward the inner wall surface of the case body.

7 . The manufacturing method of the battery case as claimed in claim 6 , wherein the leading edge of the punch is rounded into a first curved surface having a predetermined curvature, and an upper surface of the punch opposite to the bottom surface is withdrawn away from the rounded leading edge.

8 . The manufacturing method of the battery case as claimed in claim 7 , wherein an outer wall of the punch between the leading edge and the upper surface has an inclined surface or a second curved surface having a curvature different from the curvature of the first curved surface.

9 . The manufacturing method of the battery case as claimed in claim 4 ,
wherein the case body is formed such that an upper end thereof is higher than a designed height before forming the mounting surface and the depressed corner, and the upper end of the case body is trimmed at the designed height or a level higher than the designed height before forming the mounting surface and the depressed corner.

10 . The manufacturing method of the battery case as claimed in claim 4 , wherein an upper end of the case body is trimmed at the designed height after forming the stepped portion.

Assignees

• Daiwa Can Co Ltd

Inventors

• Miyashita Rio
• Shiotani Masahiro
• Enoki Yasushi

Classifications

• H01M10/04

  Construction or manufacture in general (H01M10/058, H01M10/12, H01M10/28, H01M10/38 take precedence) · CPC title

• H01M50/15

  for prismatic or rectangular cells (H01M50/153 takes precedence) · CPC title

• H01M50/103

  prismatic or rectangular (H01M50/109, H01M50/11 take precedence) · CPC title

• H01M50/186 Primary

  characterised by the disposition of the sealing members · CPC title

• H01M50/169

  by welding, brazing or soldering · CPC title