| 摘要 |
A pump control system for an excavator is provided to solve an error of a neutral point generating signal deflection of a two-way variable resistance valve by operating two signals in one direction. A pump control system for an excavator includes main pumps(21,22), regulators(81,82), a main control valve(95), a signal pressure generation valve(85), main control valve connecting lines(37,34), pressure reducing valves(24), and orifices(23). The regulators control capacities of the main pumps. The main control valve has a plurality of spools to control a flow direction admitted through main flow lines(91,92). The signal pressure generation valve has a plurality of one-way variable resistance valves(41-48) with shuttle valves(18) connected to signal input ends(1-16) of a joystick valve and is drained to an oil tank by being connected to the regulators through flow control signal lines(96,97). The main control valve connecting lines connect the flow control signal lines and the main flow lines. The pressure reducing valves are installed on the main control valve connecting lines. The orifices are installed between the pressure reducing valves and the flow control signal lines. |
