1. Defects in the piston ring cause burning oil
①The piston ring is bitten by carbon deposits in the ring groove, which loses its elasticity and the seal is not good. The high-temperature gas rushes to the crankcase and causes burning oil. The oil ring bites and cannot scrape off the excess oil on the cylinder wall to burn the oil.
②The piston ring is excessively worn, the elastic force is weak, the opening gap is exceeded, or the piston ring is broken, and the seal is not good.
③The gap between the piston ring and the groove of the piston ring is increased, which causes the oil pump to pump oil along the ring groove from bottom to top
④The piston ring is out of round and the light leakage is large
⑤ The hole on the oil ring and the corresponding piston ring groove through hole are blocked by carbon deposits or debris, so that the oil ring cannot complete the scraping of the oil on the cylinder wall, so that the oil on the cylinder wall is burned. ⑥ The twisted ring is generated during work due to the unbalanced section Torsion can strengthen the sealing, reduce the pump oil, reduce the oil consumption, and the tapered section ring is far inferior to the working performance of the twisted ring. The wrong installation of the twisted ring and the truncated cone ring also causes the pump oil. This failure often occurs in Just after assembling the cylinder-piston group, the smoke can be emitted according to the exhaust of the locomotive, combined with the knowledge of the operator.
2. Defects in cylinder liners and pistons cause burning oil.
①The cylindricity and roundness of the cylinder liner are unqualified or the wear and tear exceeds the limit, so that the clearance between the cylinder liner and the piston increases, the oil flows into the combustion chamber, and the high-temperature gas flows down, causing the oil to burn. Generally, the roundness exceeds 0.5 mm or cylindrical When the degree exceeds 0.25 mm, the sealing is very poor. The fault needs to be analyzed and judged by understanding the service life, maintenance and auscultation sound of the cylinder and piston. At this time, it can be found that the exhaust emits blue smoke, and the engine oil port exhaust gas If the oil temperature rises and the compression is poor, after adding a small amount of coal to the cylinder for cleaning or adding an appropriate amount of oil, the compression force of the cylinder becomes better, indicating that the gap between the sleeve and the piston is too large.
②The longitudinal strain of the cylinder liner has a deep scoring mark, which causes the oil to run up along the groove marks and the high-temperature gas to run down, causing burning of the oil.
③The cylinder liner is too thick or the outer water liner is surrounded by scale, the heat conduction ability is greatly weakened, and the cylinder liner is overheated, causing the engine oil in the cylinder liner to burn.
④The cylindricity of the piston skirt is generally small up and down, if the contrary, it will greatly increase the oil consumption.
3. When the clearance between the valve rod and valve guide is too large
The engine oil will burn into the cylinder combustion chamber from the gap. Because when the intake valve is opened, the cylinder will produce suction on the oil on the duct. Especially when the diesel engine is working at a lower speed, the oil consumption will increase exponentially. The engine oil consumed by the gas distribution mechanism accounts for 30% of the total loss.When auscultating with a screwdriver along the valve part installed on the cylinder head, a weak mid-tone knocking sound can be heard, and blue smoke can also occur from the exhaust pipe of the engine oil. .
4. The oil level in the oil pan is too high
The crankshaft was splattered with too much oil on the cylinder wall during operation, causing burning of the oil. Measure the oil level with a dipstick after 30 minutes of parking.
5. The clearance of connecting rod shoe increases
The increase of the oil splashed on the cylinder wall increases the amount of pump oil of the piston ring, and the oil burn increases. The more the connecting rod bearing bush clearance increases, the more the pressure value of the engine oil decreases. Regularity. At the same time, it can also be combined with auscultation voice for analysis and judgment.
