| 摘要 |
PURPOSE:To provide a stable steering and to improve the degree of freedom of design. CONSTITUTION:This power steering device is composed by providing a hydraulic change-over valve 8 which has a sleeve 8a and a spool 8b moving relatively according to the rotating angle of a steering wheel 1, a hydraulic pressure source 4 connected to the hydraulic change-over valve 8, and a steering cylinder 6 to carry out the steering by extending and contracting a piston 6c with the pressure oil from the hydraulic change-over valve 8. And, pressure reducing valves 9 and 10 to generate hydraulic pressure signals according to the displacement of the piston 6c, and hydraulic pilot ports 8e and 8f to move the spool 8b by the output hydraulic pressure of the pressure reducing valves 9 and 10 so as to make the relative movement amount with the sleeve 8a zero are also provided. |
