Patent ID: 9248489
Filing Date: 2016-02-02
CPC Classification: B21D

Claim Text:
1. A press-forming apparatus comprising: a punch; a die; a blank holder adapted to grasp a workpiece; and an upper die mechanism which includes an upper die blank holder supported by a gas spring, wherein the blank holder is divided into a plurality of parts and supported by a cushion, and wherein at least one of the divided parts of the blank holder is supported to grasp the workpiece at a timing which is different from a timing that another of the divided parts of the blank holder grasps the workpiece, and wherein the gas spring comprises: wherein a lifting load is transmitted to the upper die blank holder via the annular plate and the retainer ring at the time of lifting the upper die mechanism, and wherein the retainer ring is composed of two parts and the groove of the annular plate is formed so as to the both of the two parts can be slidably inserted.