| 摘要 |
PURPOSE:To permit the optimum control for a power cylinder and an actuator by separately installing a pressure control valve for generating an assisting force for the power cylinder and a pressure control valve for a variety of operation of the actuator and installing each flow control valve onto the both valves. CONSTITUTION:When a steering wheel 21 is manually turned, a differential pressure is generated between the chambers of a power cylinder 24 by a pressure control valve 28, and a power piston 25 is applied with a force, and a steering wheel 12 is provided with a steering assistig force, and the torque applied onto the wheel 21 is increased. A flow control valve 26 discharges a portion of working oil as the number of revolution of a pump increases, and the amount of feed into the cylinder 24 is reduced, and thus over-steering during high-speed traveling is prevented. The amount of working oil which is supplied into a flow control valve 27 from a discharge port 26a becomes constant after increase as the number of revolution of the pump 20 increases, and the oil is supplied into actuators 35 and 36 through a pressure control valve 45, and when the side force of a rear wheel 13 is large during high-speed traveling, the oil pressure of the actuator is increased to prevent the tow-out action of the rear wheel. |
