Excavator engine overspeed refers to the condition that the reduction ratio of the excavator engine suddenly expands during operation, lacks control, exceeds its allowable large reduction ratio, and is accompanied by a very loud noise. This type of equipment failure generally causes the excavator to be left unused After a period of time, therefore, in the spring when the excavator engine is used for a winter during the "hibernation period", care must be taken to prevent the engine from overspeeding. A very hazardous equipment failure will damage the crankshaft connecting rod and the parts of the valve mechanism, and more serious will cause the cylinder head to rise and fall, leading to malignant equipment failure.
Excavator engine overspeeding
1. Abnormalities of the diesel pump or the governor itself, such as the jam or looseness of some parts, make the governor lose the function of speed change.
2. Because external factors have changed the speed characteristics of diesel engines, additional diesel engines or other fuels enter the combustion chamber to apply for ignition.
Emergency preventive measures for overspeed of excavator engine
When the engine is overspeeding, there is no need to be at a loss. Effective emergency preventive measures must be taken to stop the rotation. Otherwise, when the speed rises to a certain level, it will cause a safety accident.
1. Quickly loosen the accelerating footboard so that it is at the position where the oil supply is terminated.
2. The fuel supply fixed bracket or the exposed diesel pump of the rack rod can quickly pull the rod back to the fuel stop position to terminate the fuel supply to the cylinder.
3. Quickly turn off the power switch on the fuel supply pipeline, exceeding the purpose of terminating the fuel supply. However, at this moment, the wholesale of refined oil in the pipeline and gasoline filter element will still apply for ignition again.
4. For engines with pressure relief mechanical equipment, the pressure relief lever will quickly come to an end to relieve pressure, expand cylinder capacity, ease engine reduction ratio, and gain time for other preventive measures.
5. If the engine overspeed occurs during safe driving, immediately put into the high speed gear, depress the brake pedal to the end, and slowly lift the clutch to drive the engine to stop due to increased frictional resistance.
6. Quickly loosen the hydraulic oil pipes of each cylinder to stop the oil supply to the cylinder; if there is no shut-off valve, the air filter should be quickly removed to block the external supply of gas into the cylinder, resulting in insufficient oxygen in the cylinder and the ignition is terminated.
Diagnosis and Solution of Excavator Engine Overspeed Equipment Failure
1.Raise quickly to speed up the pedals. If the pedals do not return to their position, the engine will no longer rise once when the engine exceeds a large reduction ratio. It is common to accelerate the pedals or pull arms and other jams. You can check the parts of the equipment along the transmission line. .
2. If the pedal is quickly retrieved to speed up, the engine deceleration ratio is then reduced or the ignition is stopped, it is a fault in the governor's own equipment. After the engine stops, the governor hood is removed for inspection. Initially check whether the grease is not Excessive or mildew, and then check whether the high and low speed gears are cracked, whether the quick pin is dislocated, whether the pressure bearing is damaged, etc.
3. If the extension speeds up the pedal and the engine deceleration ratio rises again, the pump rod will be stuck. Effective precautions should be taken to stop the engine, remove the governor hood, and move the pump rod by hand. The pump rod can be moved by hand, indicating that a certain part of the pump rod and the governor connection is stuck; if the pump rod is not moved, it indicates that the diesel pump gear oil pump is stuck, it should be disassembled and inspected to eliminate bad air, if the gear oil pump's regulating tooth fan Or if the adjusting arm is loose, the mark should be aligned and tightened.
4. If the oil supply system software is of high quality, it should be checked whether the cylinder has additional product oil wholesale or grease. For example: air filter or turbocharger grease can leak into the cylinder; how tight is the cylinder? Channeling grease, etc.
After the excavator has an overspeed equipment failure, the cause of the engine overspeed can be found according to the preventive measures, and then the engine can be started again after a thorough solution, otherwise the overspeed condition will still occur after the engine is started.
Summary: Formulate and implement a standard excavator engine preventive maintenance management plan, apply qualified and eliminated diesel engine and grease, check or disassemble the grease of the engine and governor on time, check, tighten, adjust or disassemble on time Install the relevant parts and components of the whole process of the contradiction between the supply and demand of the refined oil wholesale and the system software. Usually, you should pay more attention to whether the requirements of the diesel engine and grease are all normal, whether the color of the fire hydrant system is normal, whether the driving force is reduced, and the speed is waiting. Or when running at a low speed, is the excavator exhibiting unstable reduction ratios, it is very easy to stop the fire or the reduction ratio may increase. If there are abnormal phenomena or signs, immediately check, deal with, and establish all normal rear Applicable.
