Computer-controlled Small Tool Polishing Removal Characteristics And Technology

With the development of modern special optics technology, aspheric optical elements are used widely in optics system, the technology of computer controlled optical surfacing (CCOS) has been an important method in precision and ultra-precision machining of modern optical elements. One of the branches of CCOS is the computer controlled small tool polishing. In this article some base problems in the CCOS are studied on the aspheric surface compound machine tool. The main content and innovation include:1. The lapping and polishing mechanism are expounded. Base on the machining feature of SiC materials the two steps in polishing process of SiC materials are studied and the polishing mechanism of SiC materials are pointed out.2. The dual rotator is introduced, then kinematic principles are applied to deduce the removing function of the polishing pad of dual rotator according to the Preston assumption and the performance curves are given by computer simulation and the coefficient K is determined. The measure device is set up. Based on the work experiments are done and the typical experiment phenomena are analyzed carefully and the stability of removing function is studied.3. Under the direction of ideal removal performance and machining practice the optimization parameters eccentricity ratio and speed ratio are hunted out and the experiments are done to verify the correctness of the parameters. At the same time the effect of eccentricity ratio, speed ratio and the material, thickness of sub, geometry shape of polished die on removing efficiency are studied.4. The distributing of intensity of pressure is determined when polished die is baring partly and the controlling means of edge effect are generalized.5. The method of choosing polishing powder and polished die and compounding polishing fluid is generalized; The software of CCOS is introduced; The hanging methods of workpiece and the effect of intensity of pressure, concentration and speed ratio on quality of finish are studied; Different paths of polish are used base on different form errors; The reason for wavy error is analyzed and optimization step length of polish is determined; At last the effect of dimension of polishing pad on form error and controlling means of error convergence is studied.