Patent ID: 8695394

Claim:
A lower die for press bending comprising: a) a block body which includes a groove on an upper surface thereof, the groove extending in a right and left direction, and the block body being fixed to a bending machine; and b) a rotating block which is received by the groove of the block body and is capable of oscillating about an axis of the groove, c) wherein the rotating block has an upper surface on which a metal sheet to be bent is placed, a process groove is formed on an upper surface of the rotating block to receive a blade edge of an upper die, and the process groove is off-centered and located slightly forward of a central axis of the rotating block when seen in a cross section, and d) the block body has a front shoulder and a rear shoulder at front and rear sides of the groove with front and rear directions of the bending machine as reference directions and a level difference is defined between these front and rear shoulders such that the front shoulder is smaller in height than the rear shoulder, e) whereby, when the process groove receives the blade edge of the upper die, the rotating block rotates in the forward direction in a manner that the metal sheet to be bent is placed on the upper surface of the rotating block, and the level difference defined between the front and rear shoulders of the block body receives a front side part of the die contact of the metal sheet being inclined forward.