Precautionary characteristics and treatment measures for mechanical failure of diesel engines - News - Global IC Trade Starts Here.

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The mechanical failure of the diesel engine during operation causes damage to the basic components, which in turn leads to major mechanical accidents. Under normal circumstances, before the failure of the diesel engine, its engine speed, sound, exhaust, water temperature, oil pressure and other aspects will show some abnormal signs, that is, the characteristics of the failure. Therefore, the operator should promptly make a correct judgment based on the characteristics of the omen, and take decisive measures to avoid the accident.
1. The speed of the "speeding" fault indicates that the speed suddenly rises, and it is getting faster and faster. It is not controlled by the throttle. The sound is abnormal and harsh, and a large amount of blue smoke or black smoke is emitted from the exhaust pipe.
"Speed" is an overspeed idling, and work under load will not occur. It is only possible when the load is suddenly removed or reduced during the start or work. The main reason for the "speeding" is that the regulator system has failed, causing the oil supply to be out of control or the oil in the oil pan to be excessive. If there is a "speeding" sign, if you do not take immediate emergency measures, it will eventually lead to major accidents such as smashing cylinders and broken shafts.
The treatment measures are mainly aimed at extinguishing the fire by cutting off the oil or shutting off the gas. The emergency measures that can be taken include: first, shutting off the fuel supply and stopping the brake; second, blocking the intake pipe and cutting off the air; third, quickly releasing the high-pressure oil pipe to stop the oil supply; fourth, the vehicle is available for use in the diesel engine. High-grade heavy load (brake), causing the engine to stall due to insufficient torque.
2. Sticking cylinder failure sign The characteristic speed drops, the operation is weak, the sound is dull, the water temperature is super high, and the indication with the water temperature meter exceeds 100 °C.
At this point, sprinkle some water on the parts and it will evaporate quickly. The main reason is severe water shortage and the water cooling system fails. If the engine is shut down immediately, a sticky cylinder may be produced.
Treatment measures idling for a period of time or turning off the crankshaft to help cool down, so that the water temperature drops to about 40 °C, and then slowly add cooling water. Be careful not to add cooling water immediately, as this will cause the machine to deform or crack due to a sudden drop in local temperature.
3. The warning sign of the cylinder failure has a "click" sound in the crankcase, like the sound of a small hammer tapping the hard floor, that is, the so-called "knocking sound" oil pressure drops, and it is more obvious when it is accelerated.
The boring cylinder is a destructive mechanical failure. The main reason is that the connecting rod bolt is loosened or the bolt is stretched and the neck is too large, so that the bolt is loose or broken.
If there is a knocking sound, but the oil pressure is normal, it is not a sign of the cylinder, and should be considered from the adjustment of the fuel supply advance angle.
The treatment measures are immediately shut down for maintenance and replacement of new parts.
4. The characteristic of the burnt tile failure is boring, as if the load suddenly increases the speed, the oil pressure drops, and the exhaust smokes black smoke.
Burning the tile will cause the bearing bush and the journal to lock and extinguish. The main reason is that the lubricating oil film on the surface of the bearing bush is destroyed, the bearing bush is in direct contact with the metal on the surface of the journal, the friction temperature rises rapidly, and the surface is glued.
Immediately stop the treatment measures, remove the cover and check the connecting rod bearing bush, find out the cause, repair and replace.
5. Broken shaft failure sign features a dull knocking sound in the crankcase, the sensation of the throttle is louder, the machine shakes seriously when the idle speed is running, and the exhaust smokes black smoke.
The broken shaft is caused by mechanical fatigue at the shoulder of the crankshaft neck, and there is a gradual process from crack to break. When the recessive fission occurs, the characteristics of the omen are not obvious. As the crack expands, the characteristics of the omen are more and more obvious, and finally the broken shaft is extinguished. If there is a throttle such as a throttle or a knocking frequency that coincides, it may be at the critical point of the broken shaft. At this time, the cover is inspected and the flywheel is pushed by hand. If the axial clearance is large, and the pushing is effortless, it indicates that the crankshaft has been broken.
The treatment measures found that the omens immediately stopped the inspection and found that the crack should be replaced in time.