| 摘要 |
PROBLEM TO BE SOLVED: To prevent interference between a hook fitting unit of a vibratory hammer and an excitation device.SOLUTION: A crane 100 elevates a vibratory hammer 140 including: a hook fitting unit 149 fitted to a hook 110; an excitation device 144 suspended from the hook fitting unit 149 with a wire 143; and a gripping mechanism 145 gripping a pile 190. The crane 100 includes proximity determination means of determining whether the hook fitting unit 149 and excitation device 144 approach each other until the distance L between the hook fitting unit 149 and excitation device 144 becomes equal to or less than a threshold L1 for stop, and automatic stop control means of allowing a winding drum 105 to rotate in a winding-down direction according to a winding-down command when it is determined that the hook fitting unit 149 and excitation device 144 are not close to each other, and inhibiting the winding-up drum 105 to rotate in the winding-down direction when it is determined that the hook fitting unit 149 and excitation device 144 are close to each other. |
