Hydromechanical Deep Drawing of Cylindrical Cups using a Controllable Sealing Mechanism

Abstract

This paper covers the study of hydromechanical deep drawing of cylindrical steel cups using a controllable sealing mechanism between the blank and the draw ring. Precise control of the counter pressure curve over the punch stroke in hydromechanical deep drawing is difficult to accomplish due to fluid leakage. A controllable sealing mechanism has been developed and tested; this resulted in a die set designed to withstand fluid pressures up to 200 MPa with draw ratios up to 3.0. A micro-metering pressure control valve is used to limit the developed counter pressure to avoid die breakage. Furthermore, the ability of transferring complex microstructures from the punch onto the blank surface is investigated.