Patent ID: 7514175
Filing Date: 2009-04-07
Classification: B21D,B21K,H01M,Y02E

Abstract:
1. A method of manufacturing an anode can for a battery, the method comprising: preparing a material member corresponding to a shape of an anode can for a battery to be produced; forming a cylindrical body by deforming said material member so as to obtain a cylindrical body extending along a central axis and having a sidewall; modifying a thickness by subjecting said sidewall to press working so as to form a large thickness portion located at an end portion of said sidewall and having a relatively large thickness and a small thickness portion being a portion other than said large thickness portion and having a thickness relatively smaller than that of said large thickness portion in said sidewall, the large thickness portion has an outer circumferential surface and an inner circumferential surface, the small thickness portion has an outer circumferential surface and an inner circumferential surface, a distance between the outer circumferential surface of the large thickness portion and the central axis is greater than a distance between the outer circumferential surface of the small thickness portion and the central axis, and a distance between the inner circumferential surface of the large thickness portion and the central axis is equal to a distance between the inner circumferential surface of the small thickness portion and the central axis; and displacing the outer circumferential surface of the large thickness portion by arranging the cylindrical body having said large thickness portion and said small thickness portion formed in said step of modifying a thickness, between a die having a cylindrical opening and a cylindrical punch inserted in the cylindrical body, subjecting said sidewall to press working so that the distance between the outer circumferential surface of said large thickness portion and said central axis is equal to the distance between the outer circumferential surface of said small thickness portion and said central axis, and the distance between the inner circumferential surface of said large thickness portion and said central axis is smaller than the distance between the inner circumferential surface of said small thickness portion and said central axis, wherein a diameter of the punch is set to such a value that the punch comes in contact with the inner circumferential surface of the worked large thickness portion but not in contact with the inner circumferential surface of the worked small thickness portion.