Friends who have driven a Hitachi excavator know that any part of the hydraulic system and engine system is worn or stuck, which will cause abnormalities such as excavator operation, start-up, and construction. At the slightest, the action is slow and boring, and at the worst, the car stalls and the speed is severe , Can only be shut down for overhaul.
An owner left a message: The excavator stalled when the excavator was in gear 3. When the machine was running at high speed, the machine dropped severely and the speed would also slow down, but these conditions improved when the machine was cold. Because the construction has been seriously affected, the only way to send the machine is to the excavator overhaul factory. According to the analysis by the personnel of the excavator maintenance company, the speed of the excavator can be roughly divided into: for example, the solenoid valve gap is too large; the engine function is degraded; the main pump has a problem and so on.
Detailed analysis of the reasons for the speed drop of the excavator:
1. Some excavators use solenoid valves to control the oil circuit to cut off the oil, so as to achieve the purpose of flameout. Encountered similar problems, the solenoid valve gap is too large, and the load leads to insufficient fuel supply, so the speed drops, and the speed drops cause insufficient fuel supply to the diesel pump. This is a vicious circle and eventually leads to flameout.
2. The influence of temperature is relatively small. After all, there is a cooling device. The environmental influence is mainly air pressure. For high altitude areas, insufficient combustion of the engine affects engine performance, but the air booster also reduces the impact of high altitude. The main reason that affects the speed of the engine is the change of load. When the hydraulic system fails, it is easy to cause the speed to drop or hold the car.
3. There are two reasons for the speed drop. The engine performance is degraded and the main pump is faulty. Check the engine and the main pump. You can take out all the hydraulic filter elements first. If you see a lot of copper powder on the filter element, it means that the main pump has a problem and the main pump needs to be overhauled. You can also enter the monitoring panel to check the engine speed. The minimum throttle idling speed is more than 1,000 revolutions, the maximum throttle idling speed is more than 1300 revolutions, and the maximum throttle during work is more than 1900 revolutions.
4. If the engine output power is much lower than the rated power, first check whether the fuel filter element is blocked, whether there is any air leakage in the fuel path, whether the plunger in the fuel pump, the fuel injection head, and the fuel outlet valve are severely worn, and the air filter element Whether the intake air is unobstructed, whether the turbocharger is damaged, whether the engine is rapidly high temperature, causing the cylinder wall to be tightly closed, and the compression ratio is reduced, whether the cylinder liner components are worn and causing serious air leakage in the cylinder, etc. These are all factors that seriously affect the engine power .
Summary: The speed drop and flameout of the excavator become one of the most common failures of the excavator, and there are many reasons for the speed drop. For example, an excavator maintenance technician introduced to you that the cause of the failure must be determined through inspection and measurement before handling the failure, so that the problem can be solved accurately and quickly.
