| 摘要 |
PURPOSE:To prevent the shock of a hydraulic cylinder, by providing ports for taking off signal pressure oil in the vicinity of a position just before a piston forward limit position and a position just before a piston backward limit position in a cylindrical portion of a cylinder tube, and connecting logic valves to the ports. CONSTITUTION:A selector valve 4 is provided between a hydraulic cylinder 2 and a selector valve 3. Ports 32 and 33 are provided in the vicinity of a position just before a piston forward limit position and a position just before a piston backward limit position in a cylindrical portion of a cylinder tube 10. The ports 32 and 33 are connected to logic valves 6 and 7, respectively. A position between the logic valves 6 and 7 and a pilot operating portion 41 of the selector valve 4 are connected through a shuttle valve 5 to a remote control valve 8. Thus, only by additionally providing the ports at the two positions of the cylindrical portion of the cylinder tube 10, it is possible to decelerate a piston 15 at any positions just before the forward limit position and just before the backward limit position of the piston 15 and thereby prevent the shock of the hydraulic cylinder 2. |
