| 摘要 |
<p>PURPOSE:To prevent reduction of operability due to saturation of flow amount and make the circuit compact by connecting a pilot chamber with a tank by communicating by a hydraulic pilot type two position three-way valve mounted between the pilot chamber of a hydraulic pilot selector valve and a proportional control valve. CONSTITUTION:Check valves 15, 16 are provided in parallel with a bypass flow amount control valve 9 which controls oil pressure to hydraulic pilot selector valves 1, 2 which control actuators 7, 8 by pilot pressure of proportional control valves 3, 4. Pressure on the downstream side of this bypass flow amount control valve 9 is connected with second pilot chambers 30f to 33f of hydraulic pilot type two position three-way valves 30 to 33 to communicate due to the relation of force between this value and springs 30c to 33c, or pilot chambers 1d, 1e, 2d, 2e of the hydraulic pilot selector valves 1, 2 are connected with a tank via second restrictions 30d to 33f. Consequently, it is possible to prevent reduction of operability due to saturation of flow amount and make the circuit compact.</p> |
