| 摘要 |
PURPOSE:To enhance steering characteristics by furnishing a sleeve moving oppositely to the direction, in which a control valve spool operates, by means of the reactive force to adjust the reactive force, by quickening communication of a pump with the power cylinder, and by preventing improper flow of pressure oil owing to delay in actuation of the spool. CONSTITUTION:A signal from a car speed sensor 68 puts an actuator 61 in operation to increase the throttling amount of a reactive force adjusting valve 58, which is interposed in a communication line 57 to connect the reactive force chambers 31, 32 provided on the right and left sides of a control valve, in accordance with the increase of the car speed. If a control valve spool 30 slides either to the right or left through the operation of steering wheel, the internal pressure in one of the reactive force chambers 31, 32 situated on the side toward which the sliding is made will rise. Because a slide sleeve 24 slides oppositely to the direction in which the spool 30 slides through the action of said rising pressure, communication of the sleeve 24 with ports 25, 26 and a spool groove 34 is made in a short time. Thus improper flow of pressure oil owing to delay in actuation of the spool 30 is prevented to ensure enhancement of the steering characteristics. |
