| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic system for a construction machine, capable of enhancing stability of electric negative control.SOLUTION: A hydraulic system 100 for a construction machine for controlling a discharge amount of a hydraulic pump 10L depending on a negative control pressure generated by a negative control throttle 20L, includes: a negative control pressure sensor S1 for detecting the negative control pressure and outputting a negative control pressure signal; a pump regulator 40L for controlling the discharge amount of the hydraulic pump 10L; a controller 54 for receiving the negative control pressure signal and generating a command for the pump regulator 40L; and a phase compensation part 540 for performing phase advance compensation for the command generated by the controller 54. The phase compensation part 540 changes a frequency ωto be compensated by the phase advance compensation depending on a lever operation amount of a lever which operates a shovel 1. |
