| 摘要 |
PURPOSE:To simplify the structure and to improve the reliability by switching the rear wheels to the opposite phase or the same phase by action of fluid pressure of a metering cylinder of front wheels. CONSTITUTION:When a steering wheel 11 is turned to the left, for example, a rack shaft 15 and an operation rod 20 are largely moved to the right and a piston 22 is pressed by a stopper 27 to discharge a fluid from a metering cylinder C2. The discharged fluid is introduced into a pilot chamber 35 of a control valve for rear wheels to move a spool 36 to the left. By this operation, a discharged fluid of a pump P for rear wheels is supplied to a cylinder C3 for rear wheels to move a piston 46 to the left. Thus, the rear wheels 47 are steered in the opposite direction to the front wheels 46. When a steering angle is small, no fluid is discharged, and a controller 43 turns the rear wheels 47 in the same direction as the front wheels 14 according to the steering direction. By this arrangement, the structure can be simplified and the reliability can be improved. |
