| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic working machine capable of further suppressing cavitation during the boom lowering operation without complicating its constitution.SOLUTION: Discharged oil from a bottom side cylinder chamber 5a is led to a directional control valve 13 via an oil passage 42 (a first oil passage) branched from a first regeneration oil passage 33 of a first regeneration circuit 30, a port 41, an oil passage 29 (a second oil passage), and a port 61, merged with pressurized oil in an actuator oil passage 22 of the first regeneration circuit 30 through a second regeneration oil passage 63 (a third oil passage) formed in a neutral spool of the directional control valve 13 via a port 62 and an actuator oil passage 24, and fed to a rod side cylinder chamber 5b. Further, a part of the pressurized oil in the second regeneration circuit 60 is led to a tank 8 via an oil passage 44 (a fourth oil passage) branched from the oil passage 29, a port 43, and an oil passage 26. |
