Adaptive tooling system for enhanced process stability and punch longevity in ironing

Industrial-scale tests on a progressive forming tool with an adjustable-diameter ironing punch are presented. The punch diameter was controlled stroke-to-stroke by a PID loop using on-line cup height feedback. The system maintained constant cup height despite changing tool temperature and strip thickness that cause >6% cup height changes with a conventional punch. Using an environmentally benign lubricant at an elevated production rate, the conventional punch produced defective parts after 1200 strokes and failed after 2860, while the adjustable punch completed 6000 strokes without breakdown. The adaptive tool simultaneously improved process stability, part quality, productivity, and environmental footprint in high-volume ironing.