| 摘要 |
A cargo is hoisted and lowered via a wire rope and a sheave over which the wire rope is looped by paying out the wire rope from a drum and rewinding the wire rope to the drum. On the basis of load data relating to the cargo, which is outputted from a load cell provided in the sheave, the presence or absence of an actual load of the cargo and a shock load exceeding the actual load by a predetermined amount is detected (step 33). When the presence of the shock load is detected, the value obtained by multiplying the life subtraction value when the presence of the shock load is not detected by a correction coefficient having a value exceeding 1 is subtracted from the estimated life (step 34), and the new estimated life (the remaining usable number of times) of the wire rope is displayed (step 35). |
