Analysis of the reasons for the automatic descent of the crane hook

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During operation, cranes often experience the phenomenon of the hook dropping automatically. If this issue is not addressed properly, it can lead to accidents; therefore, it is necessary to identify the causes behind the automatic dropping of the hook. According to experts’ analysis, the problem of the crane hook automatically lowering usually occurs in the hydraulic system, between the cab control lever and the winch direction valve. This way, we can identify and analyze each issue one by one while locking in the faulty point. First, check for oil leakage from the control handle in the cab; if there is no oil leakage from the pipe that controls the lowering of the hook, it indicates that there is no issue with the handle’s control function. Then check whether the self-locking spring of the winch directional valve is damaged, as a broken self-locking spring can cause the hook to drop automatically due to the loss of self-locking. It should also be noted that the spare valve in the control valve is not equipped with any oil pipes, and the oil flow will impact the winch directional valve, causing the hook to vibrate. There are many other reasons that can cause the crane hook to descend automatically; therefore, when identifying the source of the problem, a comprehensive analysis is required in order to determine the cause as quickly as possible.