大型光学非球面超精密磨削的几何模型研究

大型光学非球面元件的特殊优越性使其在现代光学系统中是不可替代的,实现高效率、更经济的生产以满足对其数量与质量的迫切要求是光学元件的制造面临的一大难题.二轴联动的超精密数控机床是用来加工轴对称非球面光学元件的,若在工件主轴上安装可以精确给出旋转角度的码盘,并使用金刚石砂轮就可以用来进行非轴对称非球面的超精密磨削加工.在对轴对称与非轴对称两种不同非球面的曲率分析基础上,给出了两种曲面加工相应的几何模型.通过计算机仿真验证了该加工方法的简便与可靠性.对二轴联动的超精密数控机床的技术改造可以实现三维加工,为提高效率、降低设备投入提供了依据.

GEOMETRIC MODEL OF THE ULTRA-PRECISION GRINDING OF LARGE OPTICAL ASPHERIC SURFACES

Optical components of large sized aspheric surface have gained significant importance and indispensability because of their desirable properties. However, efficient and economical manufacturing techniques are still critical problems to meet the demand for precision and quantity. Traditionally 2-axis NC machine was used to manufacture axisymmetric aspheric surface. If a code disc offering accurate readings of the rotation angle is installed on the spindle, non-axisymmetric aspheric surfaces can be processed on it by employing a diamond wheel. The corresponding geometric models for two kind of aspheric surfaces were presented based on curvature analysis. By computer simulation it is verified that the machining approach can be made simple and reliable. According to geometric models the production efficiency can be improved and the equipment input can be reduced so that 3-D machining can be achieved by reforming a 2-axis machine.