Investigation of draw-bead application in deep-drawing process

Abstract

Deep drawing is a significant metal forming process used in the many sheetmetal forming industries such as automotive industry, household utensil industry, aviation industry and electrical industry. The defects of wrinkle, material thinning, and concave/convex feature are main problems to obstacle the increases in quality of deep-drawn parts. Many past researches were carried out to investigate these defects as well as to increase in quality of deep-drawn parts via experiments and numerical analysis. Absolutely, draw bead is a rib-like projection and it is usually mounted on either the die or the blank holder. It acts as a material flow barrier and controls the smooth material flow into the die cavity and over the punch of a draw die. Therefore, the use of traditional draw-bead shape is difficult and limited to control the material flow into die cavity and achieve the high quality of deep-drawn parts. In the present research, to increase the quality of deep-drawn parts by decreasing in material thinning and concave / convex feature, the free-form drawbead is proposed. As the results, in terms of material thinning and concave/convex feature, they showed that the quality of deep-drawn parts obtained by using freeform draw-bead is better than that obtained by using traditional draw-bead. Therefore, to increase in the quality of deep-drawn parts, the free-form draw-bead should be recommended to apply in deep-drawing process especially for complicated shape parts and difficult –to-form materials.