Study on Oil Film Model of Electronic Fuel Injection Motorcycle Engine Cylinder

Based on the principles of heat transfer,an oil film model in the engine cylinder was established.Under the condition of cold state,the influence of factors such as engine fuel injection,fuel drop point,cylinder inner wall temperature,and inlet fluid on the oil film is comprehensively considered to establish an oil film quality prediction model.Based on the measurement of the compensation oil quantity in the transition conditions,the variation of the oil film during the transition is analyzed.The experimental results show that the velocity of the air-flow in the intake port and the temperature and pressure on the wall of the intake port are the main factors affecting the oil film in the cylinder.Based on the abovementioned experimental and theoretical studies,an oil film distribution model for each cycle of the transition condition was established based on the engine inlet oil film model.The experimental measurement curve and model prediction curve for the fuel compensation per cycle in the transition condition from 10%load to 30%load.The model established can be in good agreement with the experimental results and meet the fuel compensation trend in the transition condition.While realizing the fuel compensation for the transient conditions,this work is definitely helpful to achieve accurate control of the air-fuel ratio.

Syntheses and Tribological Property of CrMoN/MoS2 Multilayer Films on Piston Rings of Heavy Vehicle Engine

In order to prolong the service life of piston rings of heavy vehicle engine and decrease the friction and wear of piston rings and cylinder liner,CrMoN/MoS_2 multilayer films were deposited on the surface of rings by magnetron sputtering and low temperature ion sulfuration.FESEM equipped with EDX was adopted to analyze the compositions and morphologies of surface,cross-section,and wear scars of the multilayer films.The nano-hardness and Young＇s modulus of the films were measured by a nano tester.Tribologicalproperties of the films were tested by an SRV~174;4 wear tester.The experimentalresults indicate that the structures of the multilayer films are dense and compact.The films possess nano hardness value of approximately 26.7 GPa and superior ability of plastic deformation resistance.The multilayer films can activate solid lubricating,and possess an excellent antifriction and wear resistance under the conditions of heavy load,high frequency,high temperature,and dynamic load.