CAPACITY CONTROL DEVICE FOR HYDRAULIC PUMP IN HYDRAULIC CONSTRUCTION MACHINE

摘要

PURPOSE:To perform capacity control of a hydraulic pump so as not to deteriorate operation of each actuator in the case that a plurality of actuators having different load pressures are simultaneously operated by means of a common hydraulic pump. CONSTITUTION:A load pressure is fed back to a hydraulic pump 11 when a turning motor 7 and a boom cylinder 8 are simultaneously operated. The load pressure is controlled within a range between a load pressure of the turning motor and the load pressure of the boom cylinder by means of a block valve 23. The block valve is a modulation type which is continuously switched.