| 摘要 |
PROBLEM TO BE SOLVED: To increase a return travel speed of a pressure booster rod while supplying oil, to eliminate ineffective strokes, to reduce wears, damages or the like in a packing and simultaneously to unnecessitate a precision process to machine the end of the pressure booster rod by eliminating a stroke where the end of the pressure booster rod travels beyond the packing, and to facilitate an air releasing property. SOLUTION: An opening end 7a of an oil supply passage 7 is provided on the side of a hydraulic cylinder 2 beyond a sealing packing between a rod through hole 5 and a pressure booster rod. A control valve 22 operated to open by a reversing pneumatic pressure which reverses a pneumatic piston is integrated in the course of the oil supply passage 7. The installation position of the packing is such that the end of the pressure booster rod does not travel beyond the packing when the pressure booster rod reverses to the maximum extent.
|
