Development of Experimental Numerically Controlled Cushion System and Its Effects on Drawability

실험용 수치제어 쿠션 시스템의 개발과 드로잉 성형성에 미치는 영향

It is well known, for many years, that deep drawability can be improved by applying variable blank holding force. To apply variable blank holding force during cup during, we set up pressure controlling system on experimental hydraulic press, and the pressure control system is often called NC(Numerically Controlled) cushion system Using the NC cushion system we compared the drawability of square steel cups with NC cushion and that with conventional cushion. The results show drawability is greatly improved when the pressure control curve is designed in a S-shaped curve. This paper includes design details of the NC cushion system and experimental analysis of drawability with experimental NC cushion system.