FLUID FLOW CONTROL APPARATUS FOR HYDRAULIC PUMP OF CONSTRUCTION MACHINE

摘要

An apparatus for controlling the flow of a hydraulic pump of a construction machine according to the present invention includes: a pressure sensor 80 detecting pressure signals corresponding to various control signal input values of the construction machine; a shuttle block 70 including a plurality of shuttle valves 70a and 70b dividing hydraulic lines 81 connected with the pressure sensor 80 into groups and extracting pressure oil of a hydraulic line under the highest pressure among hydraulic lines 81 included in the corresponding group; auxiliary pressure sensors 60a and 60b detecting the pressure of the pressure oil discharged from the shuttle block 70; electro proportional control valves 40a and 40b in which opening rates are adjusted according to an applied signal and flows applied to signal lines 33a and 33b are controlled to adjust discharge flows of main pumps P1 and P2; and a controller 50 controlling the electro proportional control valves 40a and 40b so that the opening rates of the electro proportional control valves 40a and 40b are adjusted according to the magnitude of the pressure signal at the time of applying the pressure signal from the pressure sensor 80, wherein when the pressure sensor 80 is judged as abnormal, the controller 50 controls the operate rates of the electro proportional control valves 40a and 40b to an opening rate corresponding to the magnitude of a signal outputted from the auxiliary pressure sensors 60a and 60b.