Pressing method and system wherein cushion pin load is detected by load detector for diagnosis for even distribution of blank holding force

摘要

Pressing method and system wherein a drawing operation on a blank (40) is performed by a die (18) and a punch (10) during a movement of the die with a pressure ring (28) relative to the punch against a movement resistance applied to a cushion platen (26), such that the blank is held by and between the pressure ring and the die, with a blank holding force which is generated based on the movement resistance of the cushion platen and is transmitted to the pressure ring through cushion pins (22) interposed between the cushion platen and the pressure ring, and wherein a load which is transmitted to the pressure ring through each cushion pin (22) during the drawing operation is detected, and a determination is made as to whether the blank is adequately held by the blank holding force, depending upon whether a predetermined characteristic value or values of the detected load transmitted through each cushion pin satisfies a predetermined condition for even distribution of the blank holding force to the pressure ring through all of the cushion pins.