Reduction of Blanking Noise by Controlling Press Motion

To reduce blanking noise with servo controlled presses, continuous two steps blanking, In which the punch is stopped at an Intermediate position before breakthrough and soon moved again to finish the process, is proposed. Plates of carbon steels, 18-8 stainless steel, titanium and copper are tested. When the punch is stopped just before breakthrough, the noise can be reduced to a very low level especially for high strength carbon steel plates. The mechanism of noise reduction in the process is clarified through the measurement of sound wave and machine vibration together with short-time FFT analysis.