为实现高精度中小口径非球面的加工,介绍了一种非球面修抛技术。基于Preston假设,将抛光过程描述成一个线性方程,计算得到材料的去除量与抛光时间、抛光压力和零件转速之间的函数关系。设计了整体修抛法和环带修抛法两种方法,在数控抛光的基础上,对口径为Ф117 mm的凹抛物面和口径为Ф17 mm凸双曲面进行修抛,修抛后非球面的面形精度PV值为0.184 μm,RMS均小于0.032 μm,达到了工程化应用要求,实现了中小口径非球面的高精度加工。

A high precision correction polishing technology for middle or small aspheric is introduced in this paper. The polishing process is described as a linear equation by Preston hypothesis. The function relationship about material removal rate, polishing time, polishing pressure and the lens rotational speed is obtained by calculation. Two correction polishing methods that include the whole polishing and annulus polishing are designed. Based on NC polishing, Ф117 mm concave paraboloid mirror and Ф17 mm convex hyperboloid mirror are polished. The results show that the final surface figure of the aspheric surface is 0.184 μm(PV), and the RMS is less than 0.032 μm. It meets the requirement of engineering application and realizes the fabrication of middle and small size high precision aspheric surface.