| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a die cushion device of a press machine having excellent energy efficiency which is capable of suppressing surge pressure and performing excellent servo control of die cushion pressure. <P>SOLUTION: A discharge port of a hydraulic pump/motor 140 is directly connected to a lower chamber 130b of a hydraulic cylinder 130 supporting a cushion pad 128, and an electric motor 150 connected to a rotary shaft of the hydraulic pump/motor 140 is torque-controlled. The pressure (the die cushion pressure) of the lower chamber 130b of the hydraulic cylinder 130 can be optionally controlled thereby. Further, energy required for die cushion effect received by the cushion pad 128 during the die cushion effect of a press machine 100 is regenerated as electric energy via the hydraulic cylinder 130, the hydraulic pump/motor 140 and the electric motor 150, resulting in the die cushion device of excellent energy efficiency. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
