Defining of variable blank-holding force in deep drawing

Abstract

Holding force is a significant parameter, which can be modified in course of deep drawing process. Variable blank-holding force makes possible the influence on the course and final results of the process. The paper gives the original procedure for determining one type of variable blank-holding force dependence (so-called combined dependence) and a part of experimental results of its application on carbody steel sheet metal. The experiment was performed on a special laboratory computer device, which makes possible both the measurement of significant process parameters and control of variable blank-holding force. Parallel survey with results for constant blankholding force defined in a classical manner, through empiric formulas, is given here. Qualitative indicators are observed (drawing depth, work piece properties, strain distributions, drawing force, influence on limit formability).