| 摘要 |
PROBLEM TO BE SOLVED: To prevent operation amount of an operation lever and movement of a machine from being affected by the rotation speed of an engine. SOLUTION: In this hydraulic operating device of construction machinery, secondary pressure is generated in a proportional pressure reducing valve 5 by operation of the operation lever 4, a flow rate control valve 3 is controlled by this secondary pressure to supply delivery oil of a hydraulic pump 2 to an actuator. Solenoid proportional pressure reducing valves 11 and 21 are disposed in parallel with the proportional pressure reducing valve 5, the flow rate control valve 3 is controlled by high-pressure selecting the secondary pressure of the valve 5 and the secondary pressure of the valves 11 and 21, the secondary pressure of the valve 5 is detected by pressure sensors 10 and 20, and the rotation speed of the engine 1 is detected by a rotation sensor 30. When primary flow rate of the control valve 3 is maximum, based on the detection signals, a controller 40 controls the valves 11 and 21 so that the secondary pressure of the valve 5 is substantially equal to the secondary pressure of the valves 11 and 21. When primary flow rate of the control valve 3 is minimum, the controller 40 controls them so that the valves 11 and 21 generate the secondary pressure according to a predetermined function using the secondary pressure of the valve 5 as a parameter. COPYRIGHT: (C)2005,JPO&NCIPI
|
