The dump truck's bucket is not in place, and the on-site quick investigation ideas are shared

Improper collection of dump trucks is a common problem on overseas construction sites. Often, it is not necessary to directly disassemble the oil cylinder. By following the sequence from simple to difficult, the problem can be quickly identified and on-site downtime can be reduced. Firstly, conduct an external visual inspection to confirm that the cargo box is not stuck by residual stones or debris, the hinges and supports are not deformed or stuck, and there are no foreign objects blocking between the cargo box and the frame. At the same time, observe the posture of the hopper. If one side is high and the other is low, prioritize checking whether the lifting cylinder is skewed and whether the pin shaft is stuck. Next, check the control mechanism and air circuit. Many dump trucks use pneumatic control distribution valves. Insufficient air pressure, air leaks, and loose or stuck handle cables can cause the valve core to not switch properly, and the return oil channel cannot be opened normally. When operating the handle, pay attention to whether there is any exhaust sound and whether the opening and closing feel is smooth. If the valve core is stuck, you can clean it first and do not forcefully repeatedly turn the handle. Next, check the status of the hydraulic oil. If the oil level is too low and the oil turns black with many impurities, it will cause poor oil return. If the filter element is blocked, it will also limit the flow of return oil, resulting in slow collection and almost falling to the bottom. At the same time, check whether there is any leakage on the oil pipe joints and hydraulic valve surfaces. Oil leakage will directly affect the oil return efficiency. Afterwards, the focus will be on investigating the distribution valve and limit valve. Impurities in the oil sludge can easily cause valve core jamming, blockage of the return oil throttle hole, displacement or jamming of the limit valve position, which will cut off the return oil in advance and cause the bucket to stop prematurely. This is a high-frequency fault point where the bucket is not in place. If the first few items are normal, then it is judged that there is a problem with the oil cylinder itself. If the multi-stage cylinder barrel of the oil cylinder is pulled, the seal is aging and leaking, the bucket will be weak, and it will not be able to fully fall back by relying on the weight of the cargo box. There will be a significant difference in the fault performance between unloaded and overloaded states. Attention should be paid to safety during on-site inspections. During the inspection, it is necessary to provide proper support and protection for the cargo box. It is prohibited to drill down and work below the cargo box in a suspended state. After temporary handling is completed, the lifting and lowering should be repeatedly tested several times to confirm that the action is normal. The overseas construction site has a long supply cycle for accessories, and priority should be given to low-cost issues such as foreign objects, air circuits, oil, and valve cores. Internal leakage of oil cylinders is a major repair item, and it should be recorded and included in the spare parts plan in advance. This troubleshooting approach is suitable for fleet maintenance personnel and drivers to conduct on-site self inspection, which can effectively shorten the time for fault diagnosis and reduce operation and maintenance costs.