CRANE AND REMOVAL METHOD OF ELASTIC MEMBER OF CRANE

摘要

PROBLEM TO BE SOLVED: To provide a crane capable of contracting an elastic member while ensuring safety, and a removal method of the elastic member of the crane.;SOLUTION: A crane comprises: a machine body; a front attachment 3; a counter weight 6; an extendable/contractible elastic member 7 connecting the machine body and the counter weight 6; an operation part 91 for performing a contracting operation of contracting the elastic member 7 to a prescribed length by a driving force from the counter weight 6; a calculation part 93 for calculating a rated total load of the front attachment 3 at the prescribed length; an operation prohibition part 92 for allowing the contracting operation when the rated total load of the calculation part 93 exceeds a prescribed value, and prohibiting the contracting operation when the rated total load is equal to the prescribed value or lower; a measurement part 96 for measuring a suspension load in the front attachment 3; and a contracting operation prohibition restriction part 95 for allowing the contracting operation by canceling the prohibition of the contracting operation by the contracting operation prohibition restriction part 95 when the suspension load measured by the measurement part 96 is equal to an allowable load or lower.;SELECTED DRAWING: Figure 2;COPYRIGHT: (C)2017,JPO&INPIT