To provide a hydraulic servo device applicable to various industrial hydraulic machines including a machine tool such as a press, and to accurately control a stroke position of a hydraulic cylinder regardless of the kind of a workpiece.
A cylinder 11 is vertically arranged, and pressure on a tube side generated by the own weight of a cylinder rod 21 is guided to a hydraulic pump 13. Pilot pressure is used for switching the capacity of the hydraulic pump 13. Higher pressure between the pressure on tube side of the cylinder 11 and the pressure on the rod side is used for pressure for switching the capacity of the hydraulic pump 13. The pilot pressure is obtained by switching an electromagnetic selector valve 16. The switching of the electromagnetic selector valve 16 follows a stroke of the cylinder rod 21. The stroke of the cylinder rod 21 is detected by a position sensor 14.
MITSUI HIROAKI
SOTANI YASUSHI
ODA SHIRO
Yasu Furukawa
Toshio Nishitani
Keiji width
Izumi Uchiyama
Yosuke Koreeda
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