TELESCOPIC BOOM DEVICE AND CRAWLER CRANE

摘要

PROBLEM TO BE SOLVED: To provide a telescopic boom device that mitigates impact on a stopper.;SOLUTION: A telescopic boom device, in which a plurality of cylindrical boom members 5a, 5b, and 5c are slidably layered and the boom members of an extending/retracting boom extend/retract stepwise according to extending/retracting actions of integrally-provided hydraulic cylinders 21 and 22, comprises a hydraulic circuit for the extending/retracting actions of the hydraulic cylinders 21 and 22, a lock mechanism for pin-connecting boom members that extend in a line in an extended state among a plurality of the boom members, and a stopper for positioning a final state of the boom members in the extended state. The boom members 5a, 5b, and 5c are provided with detection means, the hydraulic circuit are provided with pressure control means 61, 63, 67, and 68 for controlling a hydraulic fluid pressure supplied to the hydraulic cylinders 21 and 22, and the pressure control means reduces the hydraulic fluid pressure supplied to the hydraulic cylinders 21 and 22 according to detection signals from the detection means.;COPYRIGHT: (C)2015,JPO&INPIT