| 摘要 |
PURPOSE:To enable the pressure relief for various types of machine cycles by providing a pilot operated check valve in a pressurized fluid passage and connecting the other pressurized fluid feed port of a fluid pressure cylinder to the supply/discharge side of said pressurized fluid. CONSTITUTION:The movable part of a feed unit is attached to the rod 3 combined with the piston 2 of a hydraulic cylinder 1. A pilot operated check valve 5 for checking the reverse movement of hydraulic cylinder is provided in the oil passage 4 for the oil feed port of the head side of the hydraulic cylinder 1, and said check valve 5 is connected to a solenoid selector valve 7 for moving the hydraulic cylinder back and forth, through a variable throttle valve 6 combined with a hydraulic-cylinder quick traverse check valve. To advance the movable part attached to the rod 3 of a cylinder 1, a solenoid selector valve 22 for assisting the reverse movement of hydraulic cylinder is deenergized and the solenoid A of a selector valve 7 is excited, while the oil passage 11 leading to a hydraulic pump is connected to the oil passage 4 and the oil passage 13 leading to an oil tank is connected to an oil passage 8. |
