| 摘要 |
PROBLEM TO BE SOLVED: To provide an overload preventing device for a mobile type crane that can prevent data on the overload preventing device in an external storage device from being lost.SOLUTION: An overload preventing device 2, configured to acquire a load to be applied to a crane and prevent the acquired load from surpassing a predetermined value corresponding to a posture of the crane, comprises a CPU 22 that reads out posture data from an external storage device 21, acquires a load corresponding to the posture of the crane and detects that the acquired load surpasses the predetermined value. The CPU 22 is provided with: a mirror copy portion 220 that copies separately a plurality of pieces of posture data stored in the external storage device 21 to the external storage device 21 so as to create a plurality of pieces of mirror posture data; a mirror data acquiring portion 221 that when an error occurs in the posture data acquired from the external storage device 21, acquires mirror posture data corresponding to the acquired posture data; and an overwriting portion 222 which overwrites the acquired mirror posture data as posture data of the external storage device 21. |
