Quelles sont les compétences nécessaires pour identifier les pannes de grues montées sur camion à partir de dysfonctionnements de treuils?

Camion FAW avec grue XCMG 3.2T
In the operation of grue montée sur camions, les dysfonctionnements du treuil peuvent poser des problèmes importants et perturber le processus de levage normal. Être capable d'identifier et de diagnostiquer avec précision ces pannes est crucial pour une réparation rapide et minimiser les temps d'arrêt.. Dans cet article, we will explore in detail the skills and methods for identifying grue montée sur camion failures specifically related to winch malfunctions.

SHACMAN M3000 21 Grue à flèche articulée d'une tonne (8)

Imaginez un scénario dans lequel un grue montée sur camion owner is in the middle of a lifting operation. Suddenly, the winch motor stops rotating, and the crane is unable to lift or lower the load. Cependant, other hydraulic mechanisms of the crane are functioning normally. This unexpected situation can be extremely perplexing and frustrating for the operator. The first step in troubleshooting is to carefully observe and analyze the symptoms. In this case, we notice that the pressure gauge shows 0 when the lifting mechanism handle is operated. This is a key indication that something is amiss within the hydraulic system specifically related to the winch.
To begin our diagnosis, we can rule out the possibility of a hydraulic pump malfunction. If the hydraulic pump were faulty, it would likely affect the operation of multiple hydraulic mechanisms, not just the winch. De plus, when operating to the position where the two pumps are combined, if the winch were experiencing a problem due to the pump, it would typically slow down rather than completely stop working. Since other hydraulic mechanisms are working properly and the winch stops abruptly with no pressure indication, we can focus our attention on the winch circuit and its components.

SHACMAN 23 Grue à flèche articulée d'une tonne (3)

The next step is to examine the relief valve of the winch circuit. The relief valve plays a crucial role in regulating the pressure within the hydraulic system. S'il fonctionne mal, it can cause a loss of pressure and prevent the winch from operating correctly. We remove the main relief valve and conduct a thorough inspection. After cleaning and reinstalling it, if the fault persists, we need to dig deeper.
Il’s important to note that some grue montée sur camions have a remotely pilot-controlled main relief valve. This means that an additional component, such as an overwind solenoid valve, can influence the operation of the relief valve. When the overwind solenoid valve is energized, it can cause the relief valve to open prematurely, resulting in unloading and a loss of pressure in the winch circuit.

Chariot élévateur télescopique (4)

To test this possibility, we unplug the plug of the overwind solenoid valve. Cependant, even after doing so, the fault still persists. This indicates that the problem lies elsewhere within the solenoid valve or its associated components. At this point, we take a more direct approach by drawing a constant power from the power supply and using it to directly push the solenoid valve. When we do this, we notice that the indicator light on the solenoid valve is on, but there is no audible clicking sound of the solenoid valve operating normally. This is a strong indication that there is an internal problem with the solenoid valve.
To further investigate, we completely remove and disassemble the solenoid valve. Upon inspection, we discover that the return spring of the solenoid valve is broken. This is a critical finding, as the broken spring causes the solenoid valve to malfunction. Under the influence of gravity, the iron core of the solenoid valve pushes the reversing valve stem to reverse its position. Par conséquent, the winch circuit loses pressure, and the winch motor is unable to operate.

Truck with 3.2T XCMG Crane

Once we have identified the root cause of the problem, the solution becomes clear. We replace the broken return spring with a new one of the appropriate specification. After reassembling the solenoid valve and reinstalling it in the grue montée sur camion, we test the winch operation. To our relief, the fault phenomenon is eliminated, and the winch is once again able to lift and lower loads smoothly.
En conclusion, when dealing with winch motor malfunctions in grue montée sur camions, a systematic and methodical approach is essential. By carefully observing the symptoms, ruling out potential causes one by one, and conducting detailed inspections and tests of the relevant components, we can accurately identify the source of the problem. With the right skills and knowledge, even complex winch failures can be diagnosed and resolved, ensuring the reliable and efficient operation of the grue montée sur camion. Remember, patience and attention to detail are key when troubleshooting any mechanical issue.

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