SPEED CONTROL DEVICE FOR WHEEL TYPE HYDRAULIC TRAVELING VEHICLE

摘要

PROBLEM TO BE SOLVED: To effectively reduce the vehicle maximum speed of a wheel type hydraulic shovel. SOLUTION: Pilot pressure P1 generated by operating an accelerator pedal 22 is introduced through a pressure reducing valve 27 or a solenoid valve 26 to regulators 11A and 11B of variable displacement pumps 3A and 3B. The solenoid valve 26 is switched by operating a speed limiting switch 30, and as the switch 30 is switched on, the upper limit of pilot pressure P2 applied to the regulators 11A and 11B is limited by the pressure reducing valve 27. The vehicle maximum speed can thus be efficiently restricted without enlarging a motor 1.