The speed drop of the excavator refers to the speed drop or sudden engine speed drop during the operation process after the excavator is started. The speed drop of more than 300 rpm is a serious speed drop, which may lead to vehicle failure. Then you know that the excavator is dropped. Are there any reasons for speed? The following analyzes this problem for you!
Reasons for the speed of the excavator
1. Some vehicles use solenoid valves (fuel cut-offs) to control the fuel cut-off of the oil circuit, so as to achieve the purpose of flameout.
I once encountered a similar problem. The gap of the solenoid valve is too large, just like the effect of the flameout drawing. Half the load leads to insufficient fuel supply, so the speed drop, the speed drop leads to insufficient fuel supply for the diesel pump. This is a vicious cycle that eventually leads to flameout. .
2. The impact of temperature is relatively small. After all, there is a cooling device. The impact of the environment is mainly air pressure. For high altitude areas, the air is thin, the oxygen content is low, the engine combustion is insufficient, which affects the performance of the engine, but the air booster also reduces the high The effect of altitude.
The main reason that affects the engine speed drop is the load change. When the hydraulic system fails, the displacement cannot be changed, which is likely to cause a speed drop or hold back.
3. There are two main reasons for the speed drop. The engine performance is degraded and the main pump has problems. Check the engine and the main pump.
You can first take out the hydraulic filter element and see if there is a lot of copper powder on the filter element, it means the main pump has a problem. Overhaul the main pump.
You can also enter the monitoring panel to view the engine speed. The minimum throttle idle speed is more than 1,000 rpm, the maximum throttle idle speed is more than 1300 rpm, and the maximum throttle when working is more than 1900 rpm.
If there is no copper powder and the engine speed is normal, the two solenoid valves on the main pump can be removed and cleaned to basically eliminate the problem.
4. If the output power of the engine is much lower than the rated power, the simplest method should be used to judge on the construction site.
First look at whether the fuel filter is blocked, whether there is a leak in the fuel path, whether the plunger in the fuel pump, the fuel injection head, the fuel outlet valve are seriously worn, whether the air filter intake is smooth, and the engine with a turbocharger Whether the turbocharger is damaged, whether the engine is fast and high temperature, and the viscosity of the engine oil is reduced, causing the cylinder wall to be closed tightly. The compression ratio is reduced. Factors of engine power.
If the insufficient output power of the engine itself is excluded, it is necessary to consider the matching of the flow rate of the hydraulic pump and the output power of the engine.
