| 摘要 |
<p>A control system (32) and a method for controlling a hydraulic circuit (30) having on-off valves (5a, 5b) interposed between the control valve (3) and the actuator (4) for allowing and blocking a flow of hydraulic fluid therebetween, in which the control valve and on-off valves are actuated and switched in accordance with an operation signal from an operation device (11, 11A). Pressure sensors (7, 8, 9, 10) are . connected to hydraulic lines (30a, 30b, 30c, 30d) upstream and downstream of the on-off valves for detecting the pressures (PH, PR, PA, PB) in these hydraulic lines, and control unit (12) is operative to calculate, based on the pressures detected by the pressure sensors, a value (X,; X2; X3) which reduces the difference between thrusts applied to the actuator and output the calculated value to the control valve while the on-off valves are closed to thereby perform pressure matching control.</p> |
