Design and application of pliable blank holder systems for the optimization of process conditions in sheet metal forming

In this paper, an innovative blank holder concept for deep drawing is presented. The aim is to achieve a more homogeneous blank holder pressure. The blank holder is designed as an elastically deformable thin steel plate, so that deflection is possible and desired. The blank holder plate, which is in contact with the sheet, is mounted on support elements and attached to a rigid base plate, which is carried by the press pins. Therefore, the pliable blank holder is able to adjust itself to the changes in sheet thickness during the deep drawing process. The result is an uniform pressure distribution in the flange and improved material flow during deep drawing. The selected blank holder plate thickness and the arrangement of the support elements, used in the experiments, are based on the results of FEM-simulations.