Theoretical And Experimental Research Of Precision Grinding And Polishing Technology For Freeform Surface

In recent years,with the development of industry,the new structure of new parts and the surface of the workpiece become more complicated.The requirement of the workpiece surface quality is increasingly high.Therefore,an efficient and high quality method is needed to meet the requirements of development.A large number of research institutions and enterprises have carried out a large number of research and exploration,and achieved a lot of results.Based on these researches,theoretical analysis and experimental research on grinding and polishing of the freeform surface are carried out,and the optimal process planning is put forward.The work of this paper is mainly divided into several parts:1.The model of the pressure distribution in the contact area is established by means of finite element method(FEM).The velocity distribution of any point in the contact area is analyzed.The material removal function of freeform surface is established based on Preston assumption with the using of spherical polishing tool.The theoretical material removal profile and the influence of main process parameters on it is obtained by simulation.2.A passive compliant polishing mechanism is designed,which is driven by pneumatic motor and can synchronous rotation with it.The mechanism has buffering and damping functions and the workpiece surface can be protected.The polishing experiments have proved that the mechanism is feasible.3.The polishing path is deviated from the predetermined trajectory because of the vibration of the polishing system.In order to study the relationship of the main process parameters and the vibration size,the vibration model of the polishing tool is established based on the dynamic analysis.At the same time,the dynamic analysis of the contact area between the spherical polishing tool and the workpiece surface is carried out,and the friction torque equation is established which is the reason of material removal.4.The orthogonal experiment of grinding and polishing is carried out on the automatic platform to verified the theoretical model.The influence of the main process parameters on the processing results is analyzed,and the optimal process parameters are obtained.After grinding and polishing,the surface roughness of the workpiece surface is obviously reduced.There is a mirror,and the image is clear without distortion.