| 摘要 |
A flow control apparatus for a hydraulic pump of construction machinery is provided to minimize the power loss of construction machinery by converting a solenoid valve unit to minimize the discharge flow rate of a main pump if the rotational speed of an engine is lower than the standard rotational speed. A flow control apparatus for a hydraulic pump of construction machinery, for controlling the discharge flow rate of a pair of main pumps operated by an engine(E), comprises servo pistons(10a,10b) connected to swash plates(S1,S2) to control the tilt angle of the swash plates of the main pumps, swash plate control valves(20a,20b) controlling the flow direction of working fluids supplied to the servo pistons and controlling the operating direction of the servo pistons, a valve conversion unit(30) converting the swash plate control valves according to the inputted signals through a signal line(33b), solenoid valve units(40a,40b) having one side connected to an auxiliary pump(P3) and the other side connected to the signal line to supply signals to the valve conversion unit to convert the swash plate control valves, and a control unit(50) controlling the solenoid valve units if the rotational speed of the engine is below the standard rotational speed and supplying the signal pressure of working fluids discharged from the auxiliary pump into the valve conversion unit through the signal line to minimize the discharge flow rate of the main pump. |
