| 摘要 |
PURPOSE:To improve durability of a piston seal by providing a double acting type static pressure cylinder interlocked with a hydraulic cylinder on the front wheel side, laterally steering rear wheels only through a signal static pressure cylinder, and forming pressure relief openings on both sides of a static pressure piston with a number of pores. CONSTITUTION:When front wheels 5 are steered, a rising pressure in the one pressure chamber 27 is increased in a first hydraulic cylinder 25 of a rear wheel power steering device 24 through the working of an iso-phase control valve 36, and an iso-phase steering force by means of which rear wheels 32 are steered in an iso-phase to the phases of the front wheels 5 is increased. Simultaneously, a static pressure piston 70 of a static pressure cylinder 65 is also worked in linkage with a piston 7 of a hydraulic cylinder 2 on the front wheel side. In this case, input output ports 81L and 81R to switch phase control and high steering angle reverse phase control in relation to steering of the rear wheels 32 are formed in the static pressure cylinder 65. A pressure liquid relief opening communicated with the input output ports 81L and 81R and opened to the inner peripheral surface of the static pressure cylinder 65 is formed with a number of pores. |
