KNOCKOUT DEVICE OF FORGING PRESS MACHINE, AND FORGING PRESS MACHINE INCLUDING THE SAME

摘要

PROBLEM TO BE SOLVED: To prevent surely floating caused by inertia when switching from forced lift to upper limit retention of a knockout pin by simple control.;SOLUTION: A cylinder rod 22a is forcibly elongated, when a knockout pin is lifted by a mechanical driving mechanism. A pressing pressure reduction valve 35 for keeping a descending side fluid chamber 22d side of an air cylinder 22 at a first specified pressure P1 which is higher than the atmospheric pressure, and a holding pressure reduction valve 32 for keeping an ascending side fluid chamber 22c side at a second specified pressure P2 which is higher than P1 are provided, and an air pressure circuit 30 is also provided, which sends a pressure fluid having the pressure of P2 also into the ascending side fluid chamber 22c when the knockout pin is held on a holding position in the state where a pressure fluid having the pressure of P1 is sent into the descending side fluid chamber 22d.;COPYRIGHT: (C)2014,JPO&INPIT