Investigation On Correlation Among Honing Parameters,Surface Geometry And Friction Performance Of Engine Cylinder Bores

Cylinder bore-piston ring is one of the most important friction pairs in motor engines.Its friction performance and other function state directly affect the quality,grade,maintenance period of the engine.Honing is the final precision forming process of engine cylinder bores and the most significant precision manufacturing technology of the cylinder surface.As a type of abrasive machining,it effectively improves the dimension precision and surface quality of automobile engine cylinder bores.With the aim to study the effect of honing parameters on cylinder bore’s surface texture and surface roughness and to explore cylinder bore surface frictional performance,the kinematics model of cylinder bore honing process was established and the impact of honing parameters on the cylinder bore topography were investigated.The improvement of cylinder bore honed surface to lubricant diffusion and sliding pair’s friction performance were explored based on Response Surface Methodology of experimental design and multivariate statistical analysis.The main research results and achievements are as follows:The surface texture simulation of cylinder bores based upon oilstone dimension and abrasive distribution with respect to honing variablesThe kinematics model of automobile engine cylinder bore honing process was established to match the length and width of oilstone,the number of oilstone in honing head and the angle of oilstone rotates in one reciprocation stroke.By means of the model,the honing parameters could be selected to guarantee the honing integrity over the whole cylinder surface without overlap honing at the same time,which is essential to avoid the harmful effect of honing on form accuracy.Further,the depth of abrasive scratch were estimated according to the oilstone abrasive geometry and distribution under the normal load on cylinder bore surface in honing.It helps to forecast honed surface morphology.Predictive modeling of cylinder bores surface geometry against honing parameters based on Response Surface MethodologyA special cylinder clamp was designed to fit the honing process experiments of the cast iron cylinder bores on the SUNNEN SV-2410vertical honing machine.The geometrical properties of the cylinder bore surface were characterized by the Abbott-Firestone curve parameters(R_pk,R_k,R_vk,M_r1,M_r2)in terms of the contour support length ratio.The significance of each characterization parameter of the surface geometric properties on the regression model of honing parameters was investigated by means of variance analysis,which was utilized as the criterion of the selection of prediction models.In the planning of honing process,the honing parameter were developed by means of the prediction model with the surface finish requirements of the cylinder bores.The relationship between surface geometry and friction properties of cylinder bore based on multivariate statistical analysisThe oil infiltration and diffusion properties of engine cylinder hole honed surface were examined experimentally.The experiments on friction performance of cylinder against piston rod in boundary lubrication was designed and checked.The influence of the interrelated surface geometry parameters on the friction performance of the cylinder bore surface was investigated in terms of correlation coefficient.Based on the relative weight method,the relative importance of the surface geometry parameters on the friction performance of the cylinder bore surface was determined by using the multi-linear regression model.The results show that R_k is fairly the most significant surface geometry parameter which has invasive effect on the characteristic of the lubricating oil on the surface of a cylinder hole,while R_vkk is the most significant surface geometry characteristics parameter on friction coefficient of piston against cylinder bore.Both the lubricating oil invasion and the friction coefficient on the surface of the cylinder hole correlate positively with M_r2.The research achievements provides technical guidance for the lubrication and friction performance oriented control of surface geometry parameters.In order to improve the automobile engine cylinder hole friction property under the condition of minimal quantities of lubricant,through the simulation modeling and experiments,this paper explored the relationship among the honing process parameters and cylinder hole surface morphology in the finishing of engine cylinder holes,lubricating oil drops on the surface of the cylinder hole infiltration status and sliding friction performance of cylinder against piston.The theoretical and experimental results will provide technical support for the tribological property centered honing process planning of engine cylinder holes.