| 摘要 |
PURPOSE:To freely steer rear wheels by steering the right and left rear wheels with a rear wheel power cylinder assembled to a link mechanism in response to the feed/ discharge of the operating oil and moving the output member of a four-way transfer valve in the direction to eliminate the relative displacement between both the input and output members. CONSTITUTION:When an oil pressure difference occurs between both oil chambers of a front wheel power cylinder after front wheels are steered, a hydraulic actuator B drives the input member of a four-way transfer valve D by a quantity corresponding to this oil pressure difference. As a result, the relative displacement occurs between both the input and output members, the four-way transfer valve D starts to control the feed/discharge of the operating oil to a rear wheel power cylinder E, and the said cylinder E starts to steer the right and left rear wheels via a link mechanism C. At the same time, the output member of the four-way transfer valve D id moved in the direction to eliminate the relative displacement with the input member. As a result, the right and left rear wheels are steered by a quantity corresponding to the oil pressure difference between both oil chambers of the front wheel power cylinder after the front wheels are steered. |
