Patent ID: 6332347
Filing Date: 2001-12-25
Classification: B21J

Abstract:
An apparatus for full-enclosed die forging, comprising:a first die on a stationary frame;a second die on a movable frame which moves toward and away from the stationary frame to come into and out of contact with the first die; anda first punch on the stationary frame and a second punch on the movable frame which plunge into a cavity formed by the closed pair of these dies from the opposite sides, thereby forging a material into a workpiece having concavities on its opposite end surfaces; whereinthe first die is movable in a forging direction in a die housing provided on the stationary frame and is biased to the second die by a first spring member, and a plurality of die engaging members in the die housing adjacent the first die and which are biased into the die housing, andthe second die is attached to a slide member provided slidably in the forging direction on the movable frame and is forced together with the slide member to the first die by a second spring member, and a thrusting portion on the slide member for thrusting the die engaging members inside the die housing to engage the die engaging members with the first and the second dies after the first die and the second die are closed to each other in the process of the advancement of the movable frame, and further comprising:a differential mechanism for causing the slide member to move forward according to the advancement movement of the movable frame at a speed slower than the speed of the movable frame after the die engaging members are engage with the first and the second dies, thereby, with the first punch fixed and the second punch on the movable frame side advancing integrally with the movable frame, allowing the first and second dies advancing integrally with the slide member to move toward the first punch at a speed slower than that of the second punch.