Effect of Tooling Parameters on Bending Force in Air Bending of CR4 steel

Abstract

This study attempts to investigate the effect of process variables like the geometry of die and punch, the orientation of sheet metal and punch speed on bending force in air bending of CR4 steel, by varying one parameter at a time approach. Experiments were conducted using different combinations of sheet orientations, punch velocity, punch radius, die width, and die radius keeping sheet metal blank size constant. Universal Testing Machine was used at different speeds. Effect of parameters that is bending force has been analyzed graphically. The increase of bending force was observed due to an increase of punch radius, and punch speed. Whereas bending force was decreasing due to an increase of die width, and die radius. By changing the orientation of steel sheet from longitudinal to transverse, bending force was increasing. It was observed that the bending force follows polynomial equation of 2nd order by curve fitting method. The results will be useful as a guideline for tool design engineers and press shop engineers in the sheet metal forming industry