Research Article

Plate forging of drawn cup with flange including thickening of corners

¹ Department of Mechanical Engineering, Toyohashi University of Technology, 1-1, Tempaku-cho, Toyohashi 441-8580, Japan
² Graduate Student, Department of Mechanical Engineering, Toyohashi University of Technology, 1-1, Tempaku-cho, Toyohashi 441-8580, Japan

^* Corresponding author: abe@plast.me.tut.ac.jp

Received: 23 July 2014
Accepted: 18 September 2014

Abstract

A plate forging of a drawn cup with a flange including thickening of corners was developed to improve the stiffness of the cup. In a 3-stage stamping process, the bottom and flange corners of the cup with a flange were thickened by the plate forging. A circular blank was drawn with conical punches in the 1st and 2nd stages. In the 3rd stage, the bottom and flange corners were thickened by flattening the conical bottom of the cup with a flange. Both the bottom and flange corners of the cup were thickened by compressing the flange corner in the latter half of the 3rd stage. The amounts of thickening at both corners were improved by modification of intermediate shape. The thickening was concentrated around the two corners by preventing the thickening of the inclined portion. A wheel disk was formed by 6-stage stamping having the following three stages. The disk had 15% and 10% thickening at the bottom and flange corners, respectively, and the bending stiffness of the disk was increased. It was found that the proposed plate forging of sheet metal was considerably effective in increasing in the stiffness and reducing in the weight of automobile parts.