STEERING DEVICE FOR CONSTRUCTION VEHICLE

摘要

[PROBLEMS] A steering device for a construction vehicle, suitably used not only for traveling of the vehicle on a normal roadway but also for work of the vehicle on a construction site and the device enabling highly reliable steering operation. [MEANS FOR SOLVING PROBLEMS] The steering device has a directional control valve (5) for controlling the flow of pressurized oil to a hydraulic cylinder (2) for vehicle body bending used for steering, and the steering device also has signal generation means (6) for steering wheel, the signal operation means (6) outputting, when the steering wheel (7a) is operated, a pilot signal to the directional control valve (5) to switchover the valve (5). The steering device further has signal generation means for lever, constructed from pressure proportional solenoid valves (12a, 12b) etc. which, when a lever (10a) is operated, generate a pilot signal for switching over the directional control valve (5); selection valves (13a, 13b) switched over so that they can selectively output the pilot signals from both the signal generation means; and automatic switchover means for switching over the selection valves (13a, 13b) so that, when the steering wheel (7a) is operated, the pilot signal from the signal generation means (6) for steering wheel is preferentially outputted to the directional control valve (5).