| 摘要 |
When regenerating hydraulic fluid that has been discharged from a hydraulic actuator to drive another hydraulic actuator, in order to increase regeneration frequency and enable further energy saving, a boost circuit 36, wherein a boost communication valve 12 disposed in a communication passage 26 that connects a bottom-side conduit 23 and a rod-side conduit 24 of a boom cylinder 4, is provided, and when a first operating device 5 operates in a boom lowering direction (the direction in which the boom lowers due to gravity) and a second operating device 6 operates simultaneously with the first operating device 5, a regeneration control valve 11 is controlled such that the flow discharged from the bottom side of the boom cylinder 4 is regenerated on an arm cylinder side, which is the regeneration destination of the hydraulic fluid, by opening the regeneration control valve 11 only when the pressure on the bottom side of the boom cylinder 4 is higher than the pressure on the arm cylinder side. |
