长程面形仪稳定系统的设计

Design of Stable System of Long Trace Profiler

分析了温度梯度、空气扰动、振动以及漂移误差对长程面形仪测量精度的影响,设计了一种以双层铝合金材料为主体带夹层内水循环的封闭性防护罩结构的长程面形仪稳定系统.通过封闭性的结构设计,以及夹层内增加焊点的方式,减小了空气扰动的影响;通过导热性较好的铝合金材料和内循环水系统,提高了温度的稳定性;通过在内壁粘贴石墨导热膜,有效地避免了局部温升过大,提高温度分布的均匀性.运用ANSYS软件对稳定系统结构强度进行了校核,优化了焊点分布方案,进一步提高了结构刚度.实际测试结果表明:温度的稳定性由0.234K提高到0.186K,稳定性提高了20.5%;温度的均匀性由0.294K提高到0.232K,均匀性提高了21.1%,完全达到了应用要求;对K-B镜样品的实际测试表明,配有稳定系统的长程面形仪测量装置面形测量精度更高,噪声更小;自准直仪的性能测试表明,安装稳定系统后自准直仪的噪声得到了高效抑制,检测性能大幅提高.

Analyzing the influence of the temperature gradient,air disturbance,vibration and drift error on the measurement accuracy of the long trace profiler(LPT),a stable system was designed for the LPT,that body made mainly with double deck Aluminum alloy material and a closed shield structured with interlayer water cycle cover.To improve the stability of the system,several measures were introduced,for example,designing the closed structure and increasing solder joints of the interlayer to reduce the influence of air disturbance;selecting Aluminum alloy materials with good thermal conductivity and circulating water system to improve the temperature stability;taking the graphite thermal film for the inner wall paste to avoid local excessive temperature rise and improve the temperature distribution uniformity.The ANSYS software was used to check the structural strength of the stable system,optimize the distribution of solder joints,and further improve the structural stiffness.The actual tests of the K-B mirror samples show that,the measurement accuracy of the LTP device with stable system is higher and less noise for surface shape measure.Performance test of the self collimator installation shows that,the noise of autocollimator with stable system can be efficiently suppressed,greatly improve the detection performance.