| 摘要 |
PURPOSE:To enhance the maneuverability for change-over between steering modes by providing, in a CPU, a control section for controlling directional selector valves for front and rear steering cylinders in accordance with detected values concerning steering angles and steering directions of front and rear wheels. CONSTITUTION:A potentiometer 10 is attached to a rotary center pin 8 in a drag arm 7 in a front wheel 4 so as to constitute a front wheel steering angle detecting means. A potentiometer 20 is attached to a rotary center pin 18 in a drag arm 17 in a rear wheel 14 so as to constitute a rear wheel steering angle detecting means. Further, a rotary encoder 20 is provided in the rotary base part of the steering 21 so as to constitute a steering direction detecting means. A whole hydraulic controller 23 feeds hydraulic oil to directional selector valves 25, 26 and a main control valve 27 from a hydraulic pump 24. Signals indicating steering angles detected by the potentiometers 10, 20 are A/D- converted and are then delivered to a CPU together with a signal transmitted from the rotary encoder 22, and accordingly, a control section in the CPU changes over steering modes so as to enhance the maneuverability. |
