| 摘要 |
PROBLEM TO BE SOLVED: To execute stable forming by controlling an instantaneous back pressure generating in a die cushion side in the case of turning from a descending terminal into ascending of press forming. SOLUTION: A pressure accumulating knockout tank 6 is provided in addition to an ascending tank 4 and a drawing pressure adjusting tank 5, a lock means 9 which holds a pressure accumulated within the knockout tank 6 for a while is also provided, a pressure generating within a die cushion side main cylinder 3 by a pressure in press forming is accumulated within the knockout tank 6 and the ascending tank 4 and held for a while, and the accumulated pressure is released by releasing the lock means 9 after a pressing pressure becomes extinct and operated as an ascending pressure for a main piston.
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