Φ380mm薄镜面预应力研磨及检测研究

Study on Stressed Mirror Lapping and Testing ofΦ380 mm Thin Mirror

由于大口径望远镜主镜的拼接子镜为离轴非球面,所以增加了镜面的加工和检测难度。为了进一步提高离轴非球面子镜的加工效率和缩短抛光周期,本文利用预应力加载方法和基于蓝牙传输的接触式二维位移传感器阵列检测方法与相关装置,完成Φ380mm口径的离轴非球面子镜的研磨实验。首先介绍预应力镜面加工的原理,接下来介绍Φ380mm微晶玻璃镜面预应力研磨技术的检测方法和加载实验结果,然后介绍预应力研磨的收敛特性,最后利用三坐标测量机和接触式二维位移传感器阵列两种检测方法对研磨镜面的最终面形进行交叉检验。实验结果表明,预应力研磨方法具有可行性和较高的加工效率。

Since the spliced sub-mirror of the primary mirror of the large-aperture telescope is off-axis aspherical,it increases the difficulty of mirror processing and inspection.In order to further improve the processing efficiency of the off-axis aspheric sub-mirror and shorten the manufacture cycle,the stressing loading method and the bluetooth-based contact two-dimensional displacement sensor array detection method and related devices are used to complete the lapping experiment on an off-axis aspheric segment with a diameter of 380 mm.First,we introduce the principle of stressed mirror processing.Then,we introduce the test method on stressing lapping and loading experimental results on theΦ380 mm glass-ceramic mirror.Second,we introduce the convergence property of the stressed grinding processing.Finally,three coordinate measuring machine and contact two-dimensional displacement sensor array are used to cross check eventually surface shape of lapped mirror.The experimental results show that the stressed grinding method is feasible and high processing efficiency.