| 摘要 |
<p>The device consists of a mobile machine on which are mounted pile drivers (2,3,4,5) that are raised by the action of hydraulic jacks (7,8,9,10) operating pulley systems (25,26) whose rope ends are connected to the pile drivers (2,3,4,5). The complete units (20,21,22,23) can be tiled from the horizontal to their vertical working position by jacks (41). Oil is supplied under pressure from a pump (12) to the electro-hydraulic spool valves (18) that supply oil to the jacks (7,8,9,10) to raise the pile drivers. A pressure accumulator (14) is included in the feed line to improve the efficiency of the system. The discharge side from the jacks is via the electro-hydraulic spool valves (19) and piping (59) to tank. In this reflux circuit is a second accumulator (20) to enable a fast controlled discharge of the oil from the jacks as the pile drivers descend. The system is autom-ated by sensors (29) positioned at the top and bottom of the stroke to operate the valves (18,19).</p> |
