Study on multi-stage sheet metal forming for automobile structure-pieces

Automobile structure-pieces are usually stamped by multi-stage sheet metal forming. The stage number and the content of every stage decide if the structure-pieces can be formed successfully and the final forming quality. In this paper, the forming characteristics of left-rear hanger are analyzed firstly and two-stage drawing pattern is adopted. Then four kinds of schemes are used to research the influence of different drawn patterns and deformed amount on the forming quality of subsequent drawing. By means of FLD, changes of sheet metal thickness, distribution of maximum major strain and the drawing safe deformability, the multi-stage forming process design of automobile structure-piece is researched finally.