非球面模具超精密补偿加工技术

为了实现非球面模具的超精密数控加工,研究了加工轨迹算法原理及整个软件系统的结构与实现.提出了基于表面粗糙度均匀化的工件进给速度控制法,分析了工具磨损误差和工件形状误差,重点提出了误差补偿方法,同时也讨论了采用砂轮平行磨削法时避免加工干涉的方法.软件能生成高精度的加工与补偿加工数控程序文件.最后,在一台镜面磨床上实验加工直径为6 mm的碳化钨透镜模具,经过多次补偿加工后,获得了谷峰值为0.123μm,误差均方根为0.021μm的表面形状精度.

Compensation Processing Technique for Ultra-Precision Aspheric Molds

In order to achieve ultra-precision numerical control processing for aspheric molds,the principle of aspheric trajectory algorithm and the structure and implementation of the whole software system were studied.A workpiece feed rate control method based on surface roughness uniformization was proposed.With analysis of the tool wear error and the form error of workpiece,an error compensation metheod was presented and the method for interference avoidance in parallel grinding was also discussed.Numerical control program files for high-precision processing and compensation machining can be generated by software.Finally,a tungsten carbide lens mold with a diameter of 6 mm was machined on a mirror grinding machine,and after several times of compensation,form accuracy of peek-valley 0.123 μm and root mean square（RMS）0.021 μm were achieved.