Abstract
To reduce friction of billet-punch in forming of hole with high aspect ratio, a forming method with a punch with an internal channel for lubricant was proposed using a servo press in previous paper. In the proposed method, the punch moves in a manner combining pulsed and stepwise modes by controlling the press ram of servo press. Liquid lubricant is periodically supplied to formed part through the internal channel of the punch. In this report, shape accuracy of the formed hole is examined in the proposed method. The appropriate punch motion is confirmed to provide to form a hole with high shape accuracy. The mechanism is discussed using the finite element simulation.
