Patent ID: 6810663
Filing Date: 2004-11-02
Classification: E02F,F15B

Abstract:
A hydraulic circuit control system comprising:two pumps; specific control valves corresponding to said pumps for controlling hydraulic fluid supplied from said pumps to a specific actuator; a plurality of other control valves respectively corresponding to said pumps for controlling hydraulic fluid supplied from said pumps to one or more other actuators; discriminating means for distinguishing between control conditions for operating each said specific actuator alone and control conditions for operating the same simultaneously with any of the other actuators; a controller for controlling control characteristics of the specific control valves based on discriminated control conditions having functions of storing control characteristics for each respective control valve and choosing the characteristics most suitable for the control conditions from among a plurality of control characteristics stored therein, and having a function that when ascertaining combined operation of the specific actuator with any of the other actuators, the controller automatically adjusts control signals to be output to the two specific control valves so as to switch the source of hydraulic fluid to the specific actuator from the two pumps to either one of the two pumps according to pump-selecting criteria for the combined operation mode, which criteria have been set beforehand with respect to the other actuators.