PURPOSE: To efficiently use a hydraulic supply system by reducing respective output signals, respective target signals, or respective deviation signals of command input means in proportion to the ratio of the overall flow rate signal to a maximum discharge flow rate signal in response to the excess of the overall flow rate over the preliminarily determined maximum discharge flow rate signal.
CONSTITUTION: The flow rate of operating oil flowing to one driving system 5 is measured by a flowmeter. Flow rate signals of all of plural driving systems are added to obtain the overall flow rate signal corresponding to the overall quantity of the operating oil, and respective output signals, respective target coordinate signals, or respective deviation signals of command input means 7 are reduced in proportion to the ratio of the overall flow rate signal to the maximum discharge flow rate signal, which is preliminarily determined based on the capability of a hydraulic supply system 6, in response to the excess of the overall flow rate signal over this maximum discharge flow rate signal. Thus, the oil pressure supplied to an actuator 3 is not reduced to eliminate the trouble that a command is given but the actuator 3 is not driven.
YAMAMOTO TOSHIRO
SAITO FUMIHIRO
FURUKAWA CO LTD