| 摘要 |
PURPOSE:To smooth start and stop operation by providing the internal passages of a spool valve device with orifices which expand/reduce the effective area corresponding to the displacement of the spool valve and connecting start-stop changeover valves to the both ends of the spool valve. CONSTITUTION:A supply passage 24 being branched on its way is connected to the pump port 31 of a spool valve device 29, and a return passage 28 is connected to the cylinder port 30 of the spool valve device 29. The internal passages 33 and 34 of the spool valve device 29 are provided with orifices 35, 36 which expand/reduce the effective area corresponding to the displacement of a spool valve 40, and a start-stop changeover valve 41 which selectively supplies the pressure oil from a pump 25 of the return pressure oil from a cylinder 20 is connected to the both ends of the spool valve 40. A piston 21 can thereby be smoothly started/stopped without dealing any impact on the cylinder 20. |
