METHOD AND DEVICE FOR ELECTROHYDRAULIC SYSTEM OF WORKING MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a method for controlling and operating a machine platform of a working machine which includes an electrohydraulic system. SOLUTION: An working machine includes at least one oscillating motor 120 constituted to operate a machine platform. A changed speed of the oscillating motor 120 is determined. A solenoid operated valve 165 is controlled according to this determination response to that, solenoid operation valve 165 is constituted so as to produce a relief valve pilot signal 170. A two-way relief valve 130 is controlled in response to an input relief valve pilot signal 170, thereby being shifted. At least either of a high pressure bypass valve 135 and a low pressure bypass valve 140 is selected in response to a shifting of the two-way relief valve 130.