| 摘要 |
PURPOSE:To make it possible to control right and left rear wheels by the same steering angle by forming a rear wheel-control valve for controlling a pair of single rod type rear wheel-cylinders by two control units separately controlling the flowrares to chambers of each cylinder, and introducing the flowrate passed through a flow dividing valve to each control unit. CONSTITUTION:In a rear wheel steering system, a mode-changeover valve MV controlled by a controller 17 in response to the travelling condition, for switching rear wheels in phase with front wheels or in reverse phase to front wheels, and a rear wheel-flow control valve FV for controlling the flowrates from a rear wheel-pump P2 are provided. A rear wheel-control valve V2 for switching the operating pressure of a front wheel-power cylinder C to a pilot pressure, is then provided to drive single rod type rear wheel-cylinders RC1, RC2 by means of hydraulic fluid passed through the valve V2. In this instance, the rear wheel-control valve V2 is composed of control units LV, BV separately controlling the flowrates to rod side chambers 26, 29 and bottom-side chambers 27, 28 of each cylinder, and a flow dividing valve FD splitting the delivery fluid into each control unit LV, BV. |
