The Study On Friction And Wear Of Engine Piston And Lubrication Characteristics Of Lubricant

In recent years,China's automobile manufacturing technology has developed rapidly.The cylinder liner piston ring is the most important part of the engine,and its friction and wear loss is reduced,which greatly improves the fuel efficiency of the engine.In this paper,In order to reduce the wear of the cylinder liner piston ring,the quality of the lubricant is improved.The addition of nanographite and nanocomposite carbon particles to the lubricating oil enhances the anti-wear properties of the lubricating oil.However,nanographite and nanocomposite carbon particles have interface problems in lubricating oils.The nanographite and nanocomposite carbon particles are subjected to a modification test to enhance the suspension stability in the lubricating oil.The graphite is modified by oleic acid and stearic acid to obtain a modified flocculent graphite additive.The nanocomposite carbon is modified by a titanate coupling agent or the like to finally obtain a nanocomposite carbon additive.The morphology and microstructure of modified nanocomposite carbon and modified flocculent graphite were studied by TEM,SEM,EDS,XPS and Raman.The nanographite and nanocomposite carbon particles lubricating oil additives were added to the 350 SN lubricating oil and tested for stability with good stability.Use two modified lubricant additives and 350 SN to configure different proportions of lubricant.The cylinder liner piston ring sample is processed to facilitate the friction and wear test.The reciprocating wear test was carried out using the modified nanographite and nanocomposite carbon particles lubricating oils,and the friction coefficient and wear amount of the sample were measured.The morphology and microstructure of the wear surface of the cylinder liner piston ring were analyzed using SEM,EDS,and super depth of field.Studies have shown that there is an optimum ratio of The nanographite and nanocomposite carbon particles additive lubricants.The friction coefficient and wear amount of the sample using 0.075% modified flocculent graphite additive lubricant are lower,the surface of the cylinder liner piston ring is relatively smooth,and the pits and furrows are less.The friction coefficient and wear amount of the test using the 3% nanocomposite carbon lubricating oil additive are reduced,the wear surface is smooth and clean,and the wear scar depth and width are uniform.In order to compare with the practical of lubricating oil,the best ratio will be added to domestic lubricants.Finally,0.075% modified flocculent graphite lubricant,3% nano composite carbon lubricant,domestic lubricant and foreign lubricant were obtained.The four lubricants were designed for friction and wear tests according to different frequencies,different loads and different temperatures.After a series of friction and wear tests,it was found that 3% nanocomposite carbon lubricant has better anti-wear and anti-wear effect,followed by 0.075% modified flocculent graphite lubricant.The friction and wear test was carried out under high temperature and high pressure and high frequency conditions.By observing the microscopic morphology of the wear scar,it was found that the nanocomposite carbon can weaken the furrow effect and adhesive wear.It reduces the wear of the piston ring of the cylinder liner and achieves the effect of reducing wear and friction.Finally,according to a certain cylinder liner piston ring solid model,a 3D model of the cylinder liner piston ring is established.Statics,modality,kinetic analysis and thermodynamic analysis were performed using the finite element software Workbench.Fluent fluid simulation software was used to analyze the oil film bearing capacity.Combined with the second chapter and the third chapter,the pressure field distribution of the four lubricating oils under the furrow model was analyzed.The nanocomposite carbon lubricating oil has the strongest pressure bearing capacity.