Abstract

This paper presents investigations on multi-stage deep drawing for producing a flat and deep rectangular case, of which a cross section is high aspect ratio. Effects of a blank shape on a formability was investigated for preventing a local thinning and a large ear by using the finite element method (FEM) analysis. The multi-stage deep drawing was composed of four stages. The first and the second stage were deep drawing and redrawing process, and the third and the fourth stage were ironing process. The blank was the rectangle with the elliptic corners, and the longitudinal length and the elliptic corner length was changed. The local thinning and the ear were reduced by appropriately setting the longitudinal length and the elliptic corner length. In addition, the effect of the aspect ratio on the formability was small. Therefore, the optimized blank could be applied for forming the flat and deep rectangular case with various aspect ratio.