After the excavator is started, the operation efficiency is low, and the phenomenon of insufficient power and slow speed appears, but there is no abnormal phenomenon when the engine working condition is checked. According to this situation, it can be judged that the internal wear of the variable piston pump of the hydraulic pump of the excavator is serious, the sealing performance is reduced, resulting in internal leakage, and the leakage leads to the change of the normal working pressure parameters in the confined space. In addition, the oil temperature is too high, the speed is reduced, and the high pressure working environment can not be generated, resulting in slow and weak action.
When such a failure occurs, we first remove the hydraulic pump for inspection, find the damaged parts, repair those that can be repaired, and replace those that cannot be repaired. After the equipment of each part is completed, the matching parameters such as flow rate, pressure and power should be debugsed until the value reaches the specified range. Multi-channel valve is an important hydraulic component of excavator, which mainly consists of oil filling valve, secondary valve, main safety valve, relief valve and so on. If the pressure of these valves cannot reach the standard pressure, it will lead to a failure of digging weakness. In addition, if the valve stem and valve after a long time of work wear so that the gap between each other exceeds the specified value, the valve stem can not return to the working point, resulting in the reversal is not in place, and then produce internal leakage, reducing the pressure, which is the reason for the speed reduction.
If such a failure occurs, first of all, we remove the multi-channel valve and use professional tools to test. If the pressure value of the relevant components is found to be less than the specified range, it must be debugs until the standard parameters are reached to ensure that the gap between the valve stem and the valve reaches the specified value; Some hydraulic pumps on excavators are equipped with pilot gear pumps. If this kind of excavator fails to work, we must consider the serious wear caused by the pilot gear pump. The solution is first to re-set the pilot safety valve, if the problem is still not solved, replace the pilot gear pump. The last situation is that everything is normal when the cold machine, but the heat machine has low efficiency and weak digging. The problem of this phenomenon is still in the hydraulic pump, because the working environment of the hydraulic pump is easy to lead to the wear and aging of the accessories, so it should be removed for inspection and debugging, and the damaged parts should be replaced, and the parameter values should be adjusted in place.
Deteriorated hydraulic oil may also cause the excavator to show fault, so we should often pay attention to the quality of hydraulic oil, judge the quality of oil by looking at the flow, viscosity and impurities of oil, and so on. We should often see and change in time to minimize the occurrence of such failures.
