PADDY FIELD IMPLEMENT ELEVATOR

摘要

PURPOSE: To provide a paddy field implement elevator in which a single acting type hydraulic cylinder for elevating or lowering the paddy field implement is controlled with an electromagnetic control valve and in which a hydraulic circuit structure is simple and can be made at a low cost. CONSTITUTION: A pilot type check valve 29 is disposed in a pressure oil-charging or discharging oil passage(b) communicating with the hydraulic cylinder 6. When a main spool 23 is placed at a neutral position, a pressure oil-charging oil passage(a) and the pressure oil-charging or discharging oil passage(b) are shut off, when the main spool 23 is placed at the neutral position. A pilot oil passage(d) for opening the passage of a pilot type check valve 29 communicates with a tank via the main spool 23. The pressure oil-charging oil passage(a) communicates with the tank via a pressure-compensating valve 33 energized and closed with a spring 32. A pilot oil passage(f) for opening the passage of the pressure-compensating valve 33 is connected to the pressure oil-charging oil passage(a). A pilot oil passage(e) for opening the passage of the pressure-compensating valve 33 communicates with the pressure oil-charging or discharging oil passage(b) and the pilot oil passage(d) for opening the passage of a pilot type check valve 29 via a shuttle valve 31.