Patent ID: 7363709
Filing Date: 2008-04-29
Classification: B60B,Y10T

Abstract:
1. A wheel manufacturing method comprising a pressing step of press-molding a material plate consisting of a rolled metal plate using a die and punch to manufacture a primary molded product with a cylindrical shape having a bottom, which has a flange part that extends outward on one end part thereof, a cut-away step of cutting away the bottom part of the primary molded product to manufacture a cylindrical secondary molded product, and a spinning step of forming the secondary molded product into a rim shape by means of a roller, wherein the flange part and vicinity thereof of the primary molded product are formed to have an increased thickness by damming during press-molding by using a die in which the curvature radius in the corner parts of the punch insertion side end part is set so that the plate thickness of the flange part and vicinity thereof of the primary molded product is 15 to 30% greater than the plate thickness of the material plate in said press-molding step, and the secondary worked product is externally mounted on a mandrel so that the flange part is on the design surface side, and a hump molding roller is pressed against the increased-thickness portion of the secondary molded product to form a hump part, using a mandrel in which the outer circumferential surface corresponding to the hump part on at least the design surface side is formed into a flat circumferential surface, in said spinning process.