PURPOSE: To suppress vibration of a working equipment in its stopping state by performing auxiliary flow control of hydraulic oil for a hydraulic actuator according to the operating speed and the load pressure of the working equipment in the case of quick stop operation.
CONSTITUTION: A first detecting means 8 and 9, a second detecting means 10 and a third detecting means 13 are provided for detecting an operating signal, and also for detecting the speed of a hydraulic actuator 2 and the pressure due to its load. A first control unit 7 is provided so as to determine the flow rate command value for the pressurized oil to be supplied to and discharged from the hydraulic actuator 2 according to the speed and the load pressure of the hydraulic actuator 2 in the steady state on the basis of the values detected by means of the first, second and third detecting means 8, 9, 10 and 13. The control signal, which copes with the case where the operating signal indicates the stop, is output transiently. Furthermore, auxiliary flow control of the pressurized oil is performed for the hydraulic actuator 2 by this control signal. Thus, it is possible to suppress the vibration during the stopping state of the working equipment.
TANAKA YASUO
WATANABE HIROSHI
OBARA KIYOTAKA
