Reseach on Idle Oil Channeling of Heavy-duty Diesel
Piston rings are critical parts of diesel engine,they seal the gas and oil together with piston and cylinder liner.But in heav-y duty diesel,the intake throttle valve significantly increases the negative pressure in cylinder.When the vehicle is at idling or overrun-ning for a long time,the negative pressure in cylinder exceeds the sealing capacity of piston rings,oil in crankcase is pumped into the cylinder,accumulates to the exhaust pipe and even enters into post-treatment package.Based on exhaust manifold slobber failure of 13L heavy-duty diesel engine,the study measured idle cylinder pressure accurately and researched the influencing factors of idle oil comsuption.The fluid simulation software was used to compare the anti-channeling gas levels of different single variables to make a preliminary judgment on the theoretical analysis.Finally,the effectiveness of the simulation measures was confirmed by the slobber test for 12 hours and the oil consumption test for 100 hours.The study showed that:The upper angle of first ring changed from 7° to 7°56′,idle oil comsuption discreased 65%;The closed gap of second ring added 0.5mm,idle oil comsuption discreased 52%;The tangential force of compresstion ring did not have influence on idle oil comsuption;The tangential force of oil ring added 50%,idle oil comsuption discreased 26% .
万方数据
维普
