2014 Volume 55 Issue 638 Pages 243-247
In order to develop technologies to produce precision machine parts at low cost and high productivity, precision blanking technologies using a general-purpose press were studied. A PW die, which was expanded from Press Working punch (PW punch) technology, was used for blanking, and a conventional right-angled edge die (RA die) was also used for comparison. Three blanking methods, that is, conventional blanking, blanking with a counterload, and a method of adding an upsetting load, were used in the experiments. The experiments were performed using a 4.4mm- thickness mild steel plate with clearance changed in five steps from 0.42%t to 10.3%t. The main results of this study were as follows. 1) A mirrorlike smooth surface with a high rate shearing surface,such as 95%, was obtained using a ceramic-coated PW die with a minute clearance, under the conditions of conventional blanking and counterload blanking. 2) A gently sloping convex surface, which is desirable for precision machine parts, can be obtained by adding an upsetting load after blanking.