| 摘要 |
PURPOSE:To enable acceleration without making a pump larger by providing at least two selector valves on each of the head side and rod side of a single rod cylinder and appropriately shifting each of these selector valves depending on conditions. CONSTITUTION:Selector valves 16-23 are provided on both head side and rod side of a single rod cylinder 10 respectively, and a pressure sensor 24, a control unit 25 which carries out logical judgement to obtain a velocity ratio in accordance with a signal from the pressure sensor 24, and a shifting signal generating device 26 for shifting the selector valves 16-23 to a defined combination are provided on the delivery side of a pump 13. Thereby, when a load applied to the single rod cylinder 10 is small, the selector valves 16-23 are shifted to be defined combination due to a signal outputted from the sifting signal generating device 26, enabling acceleration without need for using a single rod cylinder of multistage velocity and making the capacity of the pump 13 larger.
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