STEERING DEVICE FOR CONSTRUCTION VEHICLE

摘要

[PROBLEM] To provide a steering system for a construction vehicle, which is suited not only for traveling on general roadways but also for work at construction sites and can performhigh-reliability steering control. [SOLUTION] A steering system for a construction vehicle is provided with a directional control valve 5 for controlling a flow of pressure oil to body-articulating hydraulic cylinders 2 that perform steering and also with a steering-wheel-operated signal generation means 6 for outputting by operation of a steering wheel 7a a pilot signal to the directional control valve 5 for switching the valve 5. The steering system is also provided with a lever-operated signal generation means for producing by operation of a lever 10a a pilot signal to switch the directional control valve 5, said lever-operated signal generation means including pressure-proportional solenoid valves 12a,12b or the like, selector valves 13a,13b switchable to permit selectively outputting the pilot signal fromone of the signal generation means to the directional control valve 5, and an automated switching means for switching the selector valves 13a, 13b such that upon operation of the steering wheel 7a, the pilot signal from the steering-wheel-operated signal generation means 6 can be preferentially outputted to the directional control valve 5.