| 摘要 |
PROBLEM TO BE SOLVED: To enable quick stop of a predetermined hydraulic actuator in a system which drives the predetermined hydraulic actuator independently of a direction control valve and regenerates energy when stopping it.SOLUTION: A work machine includes fixed displacement first and second hydraulic pump motors 20a, 20b both of which are connected to the head side of a boom cylinder 5a for operating a boom 5 and only one of which is connected to the rod side of the boom cylinder 5a, a variable displacement third hydraulic pump motor 21 to be rotated in synchronization with the first and second hydraulic pump motors 20a, 20b, and a pressure accumulator 19 connected to the third hydraulic pump motor 21 for regenerating energy along with the operation of the boom cylinder 5a. In a hydraulic pipe 25 connecting the third hydraulic pump motor 21 to the pressure accumulator 19, a boost device consisting of a selector valve 26 and a throttle valve 27 is provided as a stop control part for controlling the stop of the boom cylinder 5a. |
