Now, the excavator technology has been significantly improved. With the progress of science and technology, modern excavators basically adopt the mechanical, electrical and hydraulic integrated control mode. Therefore, in the actual operation process, if the excavator fails, we usually start from the matching problem of the engine, hydraulic pump and external load. Generally, in the process of excavator operation, the problems mostly occur in the matching of external loads. If there is no good matching in this respect, the engine speed will slow down, the operation speed will be slow, and even the excavation will be weak.

Next, let's look at the performance and troubleshooting of these problems.

Engine speed slows down

If the engine output power is far lower than the rated power, check whether the fuel filter element has been blocked and whether there is air leakage in the fuel circuit; Check whether the plunger, fuel injector and outlet valve in the fuel pump are severely worn; Whether the air inlet of the air filter element is smooth; If the engine is a turbocharger, check whether the turbocharger is damaged; Whether the engine has high temperature; Whether the oil viscosity decreases; Whether the cylinder liner components are worn. All the above faults will directly lead to the reduction of engine power; On the contrary, if the above problems do not exist, it should be considered whether the flow of the hydraulic pump matches the output power of the engine.

During the construction of hydraulic excavator, its operating speed shall be inversely proportional to the load. The product of pump output pressure and flow is a constant, and the pump output power is constant or nearly constant. If the pump control system fails, it will fail to achieve a good matching state between the engine and the pump, valve and load, which will eventually lead to the excavator unable to operate normally. As modern excavators are high-tech products integrating machinery, electricity and hydraulics, which have a high technical content, when such excavators have problems, they should start with the electrical system first, and then the hydraulic system, * check the mechanical transmission system. Here, I want to emphasize that the inspection of the hydraulic system should follow the steps of auxiliary oil circuit - control oil circuit - main oil circuit - control components.

Slow operation speed

It is not uncommon for an excavator to slow down after years of use, because the mechanical wear increases with the passage of time. Due to the wear of various parts of the excavator, the engine power of the excavator will decline and the hydraulic system will leak. Once the hydraulic system of the excavator leaks internally, it will cause poor consumption of the excavator's internal capacity, thus generating a large amount of heat energy, which will rapidly heat up the entire hydraulic system. When the temperature rises, the viscosity of the engine oil will also decline. In view of this situation, we can start from the following aspects.

1. Check whether the circuit fuse is open or short circuited;

2. Whether the pilot pressure is normal;

3. Check whether the servo control valve and servo piston are stuck;

4. Whether the distributor confluence fails;

5. Other possibilities are excluded. * Disassemble the hydraulic pump.

Weak excavator

The whole machine cannot be divided into several aspects. One is that the engine slows down sharply when the external load is large, which is shown in the following two aspects: 1. Check the engine power as mentioned above; 2. Check whether the hydraulic displacement follows the constant power output. That is, without affecting the speed, adjust the swashplate angle to reduce the displacement. Second, the engine does not slow down when the load is large, and the system speed is normal; It is necessary to debug the system pressure. Since the hydraulic components used by various manufacturers are different from the hydraulic system, the pressure of each hydraulic cylinder is also different. As long as it is debugged according to the standards specified by the manufacturer, it is OK. In addition, if the pressure of the relief valve cannot be adjusted and the relief valve is checked to be in good condition, it is necessary to check the regulating system of the hydraulic pump, as well as the cylinder body, port plate, plunger and other parts of the hydraulic pump.

The above parts are the frequent failures of hydraulic excavators in use. As the use time of the excavator gradually goes by, we need to strengthen the daily maintenance work to prevent mechanical damage caused by bad working habits. We need to find and solve problems in time. Only in this way can excavators better cooperate with us to complete each construction task and better serve our work and life.