Polishing Process Of The Polishing Tool Based On The Viscoelastic Material

With the optical surface components are widely used in our life, the traditionalpolishing process has been unable to meet the need. Along with the application ofcomputer technology in the polishing process，various computer controlled opticalsurfacing processes have been developed since the1960s. With increasinglysophisticated computer control technology, computer control accuracy and responsetime can meet the high requirements, so the computer controlled opticalsurfacing technology can get the optical surface that surface quality and surfaceaccuracy is very high.But there are still some problems in the computer controlled optical surfacingtechnology. When the processing of large and super large diameter workpiece, theefficiency of small diameter polishing tool is too low, and large diameter polishingtool is very difficult to have good flexible and rigid at the same time. During thepolishing process, polishing tool repeatedly along the same path, it will leave thespatial frequency errors in the workpiece surface. To solve above twoproblems, we adopts the following ways to conduct research:(1)We developed a newkind of polishing tool, due to its own characteristics, with the processing surface canbe well fit, the tool has certain rigidity, which solves the polishing tools do not havegood flexible and rigid at the same time;(2) We developed a pseudo-randomized evenpolishing path, the equidistant polishing path can avoid the superposition of polishingpath，and the pseudo-randomized track can remove the surface errors leaved bymachining and grinding.Research work of this paper includes about several parts：1. Based on the viscoelastic intelligent materials, a nonlinear viscoelasticpolishing tool has been designed. This tool can change its stiffness according to the different frequency force, thereby solving the flexible and rigid polishing toolimbalance. Then we modeled the material removal function and polishing tool edgeremoval function of this polishing tool. Through the experimental analysis，wevalidated performance of this polishing tool and removal function model. Finally, wequantitatively analyzed the viscoelastic properties of viscoelastic materials in thepolishing tool, according to two dynamic modulus of the viscoelastic materialmechanics.2. Generation Strategy of a pseudo-randomized even polishing path is presented.For scanning track and spiral trajectory, we proposed the generation strategy for thesecorresponding polishing tracks, on the basis of considering the polishing tool size.And according to the proposed method, the free surface was simulated trajectorysimulation, in order to verify whether such polishing track can avoid the periodicspatial frequency errors.3. By orthogonal experiment, we determined the optimum parameters whichusing the viscoelastic polishing tool. And Single factor experimental analyzed theeffects of different process parameters on the polishing effect of a single factor. Then,based on the optimum parameters, we polished the flat and curved parts, according tothe general polishing path and pseudo-randomized even polishing path, and studiedthe pseudo-randomized even polishing path in the practical effect of polishing.