| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hydraulic system for a hydraulic working machine, that can minimize the influence of deterioration of responsiveness to speed control of an actuator and securing satisfactory operability equivalent to that of a spool-type flow rate control valve. <P>SOLUTION: In the hydraulic system for a hydraulic shovel for supplying rotational power from a rotational power generation means 11 into a hydraulic pump 12 to generate hydraulic power and operating an actuator 14 by the hydraulic power, a hydraulic oil discharge oil path 20 from the actuator 14 is branched into a flow rate control oil path 21 which is an oil path connecting to the spool of a flow rate control valve 19 controlled by a lever operation and a power recovery oil path 22 which is an oil path connecting to a variable capacitance motor 23 for converting the hydraulic power of discharged hydraulic oil into reusable energy. A recovery ratio control means is provided to control the variable capacitance motor 23 to make the flow rate of the power recovery oil path 22 be a fixed ratio α set beforehand with respect to a flow rate generated in the flow rate control oil path 21 by the lever operation. <P>COPYRIGHT: (C)2013,JPO&INPIT |
