Reading Guide
The mechanical failure of the diesel engine can cause damage to the base parts, and can cause mechanical accidents. Before the diesel engine fails, some abnormal signs will appear in its speed, sound, exhaust, water temperature, oil pressure, etc., that is, the characteristics of the warning signs. Therefore, the operator should quickly make accurate judgments based on the characteristics of the omen, and judge the acceptance measures to avoid accidents.
1 "Speeding" failure
Omen characteristics
The rotation speed suddenly increased and became faster and faster, not controlled by the throttle, the sound was abnormal and harsh, and a large amount of blue smoke or black smoke was emitted from the exhaust pipe.
"Flying car" belongs to overspeed idling, and work under load will not occur. It is only possible when the load is suddenly disappeared or reduced immediately after starting or during work. The main reason is that the governor system malfunctions, causing the fuel supply to be out of control or excessive oil in the oil pan. "Fly"
"Car" warning sign, if you do not immediately take emergency measures, it will eventually lead to major accidents such as ramming and shaft breakage.
Disposal measures
The main purpose is to achieve flameout by cutting off oil or gas.
The emergency measures that can be taken are: one is to close the throttle to restrict the fuel supply and step on the brake; the other is to block the air intake pipe and cut off the air; the third is to quickly release the high-pressure fuel pipe to stop the fuel supply; the fourth is to use the vehicle diesel engine while walking High-level heavy load (braking) makes the engine stall due to insufficient torque.
2 Sticky cylinder failure
Omen characteristics
The rotation speed drops, the operation is weak, the sound is boring, and the water temperature is extremely high. The indicator equipped with a water temperature gauge crosses 100 ° C. At this point, spray some water on the machine parts, it will quickly evaporate. The main reason is severe water shortage and water cooling system failure. If the flame is shut down immediately, sticking cylinder may occur.
Disposal measures
Run at idle speed for a period of time or turn off the crankshaft to assist cooling, reduce the water temperature to about 40 ℃, and then slowly add cooling water. Be careful not to add cooling water immediately, otherwise it will cause the machine parts to deform or crack due to the sudden drop of local temperature.
3 Ramming failure
Omen characteristics
There is a "click" sound in the crankcase, like the sound of a small hammer tapping the hard floor, commonly known as the "knock sound", the oil pressure drops, and it is more obvious when accelerating rapidly. Ramming is a more damaging mechanical failure, mainly due to the loosening of the connecting rod bolts or the pulling of the telescopic neck, and the large gap between the connecting rod shafts, causing the bolts to loosen or break. If there is knocking sound, but the oil pressure is normal, it is not a sign of tampering, and it should be considered in terms of adjusting the fuel supply advance angle.
Disposal measures
Immediately shut down for maintenance and replace with new parts.
4 Tile burning fault
Omen characteristics
The sound is dull, as if the load suddenly increases and the speed drops, the oil pressure drops, and the exhaust emits black smoke. Burning the bush will cause the bush and the journal to be locked and flame out. The main reason is that the lubricant film on the surface of the bush is damaged, the metal of the bush and the surface of the journal directly contact, the friction temperature rises rapidly, and the glue
to.
Disposal measures
Immediately stop the machine, remove the cover and check the connecting rod and bearing bush, find out the reason, and repair and replace it.
5 Shaft failure
Omen characteristics
An annoying knocking sound occurs in the crankcase. When the throttle is increased, the knocking sound becomes louder. When the engine is idling, the parts tremble severely and the exhaust emits 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. In the case of recessive fission, the omen features are not obvious. As the crack expands, the omen features become more and more obvious, and finally the shaft breaks.
If there is trembling of the throttle or the knocking frequency coincides, it may be at the critical point of shaft break. At this time, the cover is removed and checked, and the flywheel is pushed by hand. If the axial gap is large and the pushing is not difficult, it indicates that the crankshaft has been broken.
Disposal measures
Stop the machine immediately and check if it finds the omen. If the crack is found, replace the crankshaft in time.
