Press working die assembly

A press working die assembly for forming a negative angle comprising:

• a pad secured to an upper die holder being freely movable upward and downward and configured to hold a work;
• a machining slide cam having cam surfaces on upper and lower sides and a bending edge on one end side, the machining slide cam being supported on the upper die holder or a lower die holder and being slidable laterally along the cum surfaces;
• a rotary cam having a bending portion configured to form a negative angle portion on the work and a cam surface for the slide cam and being rotatably supported entirely on the lower die holder so as to be rotated by an external force;
• and
• a reciprocal driving apparatus configured to rotate the rotary cam to a work machining position, wherein
• the reciprocal driving apparatus includes:
• a slide block having a cam surface configured to rotate the rotary cam in a predetermined direction on a front end side and a rotation impelling surface configured to rotate the rotary cam so as to be restored to its original position at a rear end side;
• and
• a restoring action block configured to come into abutment with the rotation impelling surface of the slide block when the slide block retracts to restore the rotary cam to its original position before machining.