HYDRAULIC DRIVING APPARATUS.

摘要

The apparatus includes a prime mover (21), a hydraulic pump (22) driven by the prime mover, hydraulic actuators (23-28) driven by a pressure oil supplied from this hydraulic pump, flow rate control valves (29-34) for controlling the pressure oil supplied to these actuators and pressure compensation valves (35-40) for controlling the pressure differences of these flow rate control valves. Each pressure compensation valve is equipped with a driving device (45-50, 35c-40c) for providing control force (f-Fc) in a valve opening direction for setting a target value of the pressure difference across each flow control valve. There are also provided devices (60) for detecting a target number of revolutions (No) of the prime mover and controlled so as to decrease the control force with the decrease in the target number of revolutions at least on the basis of the revolusions detected.