| 摘要 |
PURPOSE: To increase the regulating speed of an actuating cylinder by enabling air to be held in a chamber communicated with a pressure pipe line connected to the actuating cylinder, and by reducing the volume of the air with the use of a system pressure which is determined by a pressure limit valve. CONSTITUTION: A hydraulic actuating system comprises a pump 1 connected with a reservoir 2 through a pressure pipe line 4, and the pressure of the pressure pipe line 4 is limited to a maximum valve, as a system pressure, by a pressure limit valve 5. A pressure chamber 9 in the actuating cylinder 6 connected to the pressure pipe line 4 can be connected to the pressure pipe line or the reservoir 2 through the directional control valve 3. An annular groove 23 communicated with an axial channel 22 formed in a control piston 13 in the pump l, is connected to the front end of a housing bore 26 communicated with the pressure pipe line 4, and accordingly, a large clearance limited by this bore 26. |
