Study On Key Techniques Of Ultra-precision Grinding Of Optical Components

Aspherical and other optical components are widely used in military equipment,aerospace and other optical fields due to their excellent characteristics,and they are vital to further improve the processing accuracy and efficiency of aspheric optical components.The manufacture of optical components usually follows the process of grinding forming,lapping and polishing,and the processing cycle is too long to adapt to the short-flow rapid production requirements of modern optical systems.Starting from the main error sources affecting ultra-precision grinding,this thesis analyzes the influences of machine space motion error,rotation error of grinding wheel spindle,shaft alignment error of grinding wheel,wheel wear error and other factors on machining accuracy,and proposes an optimized process program.Experimental verification is performed on typical samples.The main research contents of this thesis include:(1)Based on the multi-body system topology theory,the spatial error model of typical ultra-precision machine tools is established.The influence of the rotation error of grinding wheel spindle on the surface figure is analyzed.The rotation error of the ultra-precision air static pressure spindle is tested on the self-developed ultra-precision grinding machine,and its grinding process ability of sub-micron precision is validated.(2)The vertical grinding form is determined and the influence of the misalignment and shape error of the grinding wheel on the surface accuracy is analyzed.With the determination of the requirement of ultra-precision grinding,the corresponding adjustment scheme is put forward.The influence of the shape error on the profile accuracy of grinding wheel is analyzed,and the rotary error of grinding wheel is measured and evaluated.(3)The influence model of the wear of the grinding wheel on the surface figure is established.The influences rule of workpiece' caliber,grinding wheel diameter and arc radius of grinding wheel on grinding wheel wear are discussed.Meanwhile,the prediction of grinding wheel wear amount is realized,and the wear compensation method is put forward.(4)Ultra-precision grinding experiments is carried out to optimize the process parameters of ultra-precision grinding,and the subsurface damage depth under the optimal parameter was measured.The results show that the subsurface damage depth under this parameter is about 1.2?m.Processing experiments are carried out on fused silica spheres and asphere with a caliber of 100 mm,and the resulting surface shape accuracy was PV 0.46?m and PV 0.53?m respectively,which achieves the expected target.