hydraulic systems for swing independent of upper body of construction machinery

摘要

The present invention relates to a hydraulic device for independent turning of a construction machine body. A hydraulic device for independent turning of a construction machine according to the present invention comprises a main pump (20) controlled by a joystick signal (70) for driving a working device or a traveling motor; A swing pump 30 controlled by a turning joystick signal 60 for turning the upper body and a control unit 50 for controlling the main pump 20 based on the engine speed rpm Wherein the control unit (50) is configured to control the horsepower control value of the main pump (20) calculated on the basis of the engine speed when the operation of the work unit and the swing operation of the upper body are required in combination, The main pump 20 is controlled to calculate the horsepower control value of the main pump 20 by reflecting the pressure value so that the absorption horsepower of the main pump 20 is controlled to be smaller than the case where only the engine speed is taken into consideration do.