HYDRAULIC PUMP CONTROL DEVICE AND CONTROL METHOD FOR CONSTRUCTION MACHINERY

摘要

The hydraulic pump control device for construction machinery according to the present invention comprises: a first swash-plate-angle adjusting unit (12) which is for controlling hydraulic pumps in construction machinery comprising a first pump (10) for supplying operating fluid via a swivel control valve (31) to a swivel motor (30) and a second pump (20) for supplying operating fluid via a working-unit control valve (41) to a working-unit actuator (40), and which adjusts the swash plate angle of the first pump (10) and thereby adjusts the volume of fluid discharged from the first pump (10) in accordance with an input pump control signal; and a controller (60) which subtracts the discharge pressure (P2) of the second pump (20) from the discharge pressure (P1) of the first pump (10) and thereby calculates the pump pressure difference (P1-P2), and which compares the calculated pump pressure difference (P1-P2) with a reference pressure difference and, if the pump pressure difference is larger than the reference pressure difference, outputs a pump control signal to the first swash-plate-angle adjusting unit (12) such that the discharge pressure (P1) of the first pump (10) becomes either smaller than a swivel relief pressure or falls below the said first reference pressure.