| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic press device in which a rise in the temperature of hydraulic oil is small, which does not require a water-cooled cooler, which is compact and with which energy saving is achieved. SOLUTION: The pressure receiving areas of a 1st cylinder chamber 51 for high-speed descent and a 2nd cylinder chamber 52 for high-speed ascent are equalized, and a closed circuit reaching a hydraulic passage 31, a hydraulic pump 7, a hydraulic passage 34 and a 1st cylinder chamber 51 from a 2nd cylinder chamber 52 is constituted. By controlling the number of revolutions of the hydraulic pump 7 by an AC servomotor 6 in both forward and backward directions, the advancing and retreating speed and the pressure of a piston body 54 are controlled.
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