| 摘要 |
<p>PURPOSE:To make it possible to uniformly maintain a piston for a long time by providing a pressure detecting means in supply/discharge pipes to drive a servo valve by a signal from the pressure detecting means and keeping the pressure of pressurized fluid in a cylinder at predetermined value. CONSTITUTION:A servo valve 10 for controlling pressure and a detecting means 32 for detecting the pressure are provided in supply/discharge pipes 9a, 9b and the servo valve 10 is controlled by a signal from the pressure detecting means 32. Accordingly, even if operating fluid leaks via a sealing portion to change pressure in a cylinder tube 1, the change is compensated so that a piston 2 can be uniformly kept for a long time.</p> |
