| 摘要 |
PURPOSE:To make the change of corrected oil pressure smooth by providing a program control circuit for controlling solenoid valves for controlling pressure to be led into an auxiliary oil pressure booster, and providing this program control circuit with a means for supplying pulse width signals to the solenoid valves so as to control the average opening of the solenoid valves. CONSTITUTION:A steering gear 2 is provided with solenoid valves 6a, 6b for leading pressure oil, generated by an oil pressure generating means 4, into an auxiliary oil pressure booster 5, and these solenoid valves 6a, 6b are controlled by a program control circuit 7 on the basis of the output of a steering force sensor 3. The steering gear 2 is also provided with a hydraulic reaction means for providing the steering wheel 1 with reaction, and pressure oil to be supplied to the auxiliary oil pressure booster 5 is led into the hydraulic reaction means through a right and a left correcting valves. In this case, the program control circuit 7 is provided with a means for supplying pulse width signals to the solenoid valves 6a, 6b so as to control the average opening thereof, and a means for controlling the pulse width signals in such a way that the average value of a control current at the 'on' time of the solenoid valves 6a, 6b becomes proportional to the time differential value for steering force. |
