TRAVEL CONTORL SYSTEM FOR CONSTRUCTION MACHINERY AND TRAVEL CONTROL METHOD FOR CONSTRUCTION MACHINERY

摘要

A travel control system for construction machinery comprises: first and second hydraulic pumps; a first travel motor; a second travel motor; at least one actuator operable by a working fluid discharged from the first hydraulic pump or the second hydraulic pump; a straight travel valve; first and second travel motor control valves for controlling flow rate of the working fluid supplied to the first and the second travel motor, respectively; first and second spool displacement control valves supplying pilot signal pressure to spools of the first and second travel motor control valves, respectively, according to an input control signal; and a control unit outputting control signals to the first and second spool displacement control valves according to a travel manipulation signal of a worker, respectively, and performing a control operation for restricting displacement amounts of the spools of the first and second travel motor control valves according to a manipulation signal of the actuator when receiving the manipulation signal of the actuator during travel operation of the first and second travel motors. The travel control system for construction machinery reduces a switching shock of the straight travel valve and improves fuel efficiency.