We often use excavators in daily engineering construction, and some faults are inevitable or local. Failure is an unpleasant and headache, delaying working hours and consuming energy. Faults are generally caused by potential or improper use in the later stage, so it is necessary for us to carry out preventive maintenance and planned maintenance in the early stage. The state that the machine cannot perform the specified functions and the work interruption planned in advance are regarded as faults.
To deal with the fault, we must first find the cause and root cause. Only by finding the source of the fault can we find a more reasonable way to deal with it. On the contrary, before failure, you must be diligent, observe and understand more. Let's briefly introduce the reasons why excavators are unable to work.
1. The engine has sufficient power and operates normally, while the excavator operates slowly and is unable to excavate.
2. The hydraulic pump of the excavator is mostly variable piston pump. After working for a certain time, the internal parts of the pump are inevitably worn, resulting in internal leakage, and the parameter data are inconsistent, resulting in insufficient flow, high oil temperature, slow speed and unable to establish high pressure, so the action is slow and weak. For such problems, it is necessary to measure the data of the hydraulic pump, confirm the problem, replace the parts that can not be used again, or repair the parts that can be used again, conduct bench commissioning after reassembly, and match the parameters of each circuit (pressure, flow, power, variable, etc.).
3. An important hydraulic component on the excavator – multi-channel distribution valve, which has main safety valve, secondary valve, overflow valve, oil make-up valve, etc. If the pressure set by these valves does not reach the standard pressure, it will lead to weak excavation. In addition, if the clearance between the valve rod and the valve hole is too large due to wear, the valve rod return is not complete and the reversing is not in place, there will be a large amount of internal leakage, resulting in insufficient flow and slow speed. For such problems, the multi-channel distribution valve shall be debugged and tested, the pressure of all valves shall be reset to the standard pressure, and the gap between the valve stem and the valve hole shall be eliminated.
4. The hydraulic pumps on imported excavators are equipped with pilot gear pumps, which are mainly used to participate in the variable of the hydraulic pump and open the valve rod of the multi-channel distribution valve as pilot oil to reverse it. If the gear pump is excessively worn and cannot establish a certain pressure, or the setting of the safety valve on the gear pump cannot reach a certain pressure, the hydraulic pump will always be in a low flow state, and the valve rod cannot be completely reversed, resulting in insufficient flow, slow action, insufficient pressure and weak excavation. For such problems, reset the pilot safety valve or test and repair.
5. Everything is normal when the engine is cold, slow when the engine is hot, and unable to dig. The occurrence of such problems indicates that the internal accessories of the hydraulic pump are seriously worn, and the vulnerable parts in the pump must be replaced, reassembled, adjusted and calibrated on the test bench.
6. Another main reason for the slow and weak operation of the excavator is the deterioration of the hydraulic oil. Therefore, pay attention to monitoring the quality of the hydraulic oil (viscosity, fluidity and presence of suspended solids, etc.) and replace the hydraulic oil in accordance with the regulations on time, so as to avoid such faults to a great extent.
