| 摘要 |
PROBLEM TO BE SOLVED: To perform the regeneration of power without adding any other special valve than a selector valve for feeding and discharging pressure oil to and from a hydraulic cylinder. SOLUTION: In the selector valve 27 for changing over the direction of the pressure oil from a hydraulic pump 22, the hydraulic pump 22 is connected to a P1 port, a bi-directional pump motor 24 is connected to a P2 port, and a tank 28 is connected to a Tn port. The bi-directional pump motor 24 is connected to an electric motor generator. A boom cylinder 18 is blocked at the neutral positionαof the selector valve 27. When the selector valve 27 is operated, the bottom side 18a of the boom cylinder 18 is always connected to the bi-directional pump motor 24, and the top 18b side of the boom cylinder 18 is allowed to communicate with the tank 28 at the extended positionβof the boom cylinder 18 and connected to the hydraulic pump 22 at the retracted positionγof the boom cylinder 18. COPYRIGHT: (C)2006,JPO&NCIPI |
