Control system for hydraulic circuit
First Claim
1. A control system for a hydraulic circuit having on-off valves interposed by means of hydraulic lines between a control valve and an actuator for allowing and blocking a flow of hydraulic fluid therebetween, so that when the on-off valves are closed, a pressure differential exists in the hydraulic lines upstream and downstream of the on-off valves whereby a thrust is produced on the actuator when switching the on-off valves to an open position, operation means for providing a signal to actuate and switch the control valve and on-off valves, pressure sensor means connected to the hydraulic lines upstream and downstream of the on-off valves for detecting the pressure in these hydraulic lines;
- and control means for calculating, based on the pressures detected by the pressure sensor means, a value representative of reduction of the thrust applied to the actuator and outputting the calculated value to the control valve while the on-off valves are closed to thereby perform pressure matching control for reducing the thrust.
1 Assignment
0 Petitions
Accused Products
Abstract
A control system for a hydraulic circuit having an on-off valve interposed between the control valve and the actuator 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. Pressure sensors are connected to hydraulic lines upstream and downstream of the on-off valves for detecting the pressures in these hydraulic lines, and control unit is operative to calculate, based on the pressures detected by the pressure sensors, a value 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.
43 Citations
7 Claims
-
1. A control system for a hydraulic circuit having on-off valves interposed by means of hydraulic lines between a control valve and an actuator for allowing and blocking a flow of hydraulic fluid therebetween, so that when the on-off valves are closed, a pressure differential exists in the hydraulic lines upstream and downstream of the on-off valves whereby a thrust is produced on the actuator when switching the on-off valves to an open position, operation means for providing a signal to actuate and switch the control valve and on-off valves, pressure sensor means connected to the hydraulic lines upstream and downstream of the on-off valves for detecting the pressure in these hydraulic lines;
- and control means for calculating, based on the pressures detected by the pressure sensor means, a value representative of reduction of the thrust applied to the actuator and outputting the calculated value to the control valve while the on-off valves are closed to thereby perform pressure matching control for reducing the thrust.
- View Dependent Claims (2, 3, 4, 5, 6, 7)
Specification