用于反射镜加工的液压支撑单元刚度特性研究  

Research on Stiffness Characteristics of Hydraulic Support Unit for Mirror Machining

作　　者：周頔 董得义[1] 王连强 胡海飞[1] 关英俊[2] 江昱含 李伟[1,3] 高明辉 Zhou Di;Dong Deyi;Wang Lianqiang;Hu Haifei;Guan Yingjun;Jiang Yuhan;Li Wei;Gao Minghui(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;College of Mechanical and Electrical Engineering,Changchun University of Technology,Changchun 130012,China;Key Laboratory of advanced manufacturing technology of optical system,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,长春130033 [2]长春工业大学机电工程学院,长春130012 [3]中国科学院光学系统先进制造技术重点实验室,长春130033

出　　处：《机电工程技术》2022年第5期10-15,122,共7页Mechanical & Electrical Engineering Technology

基　　金：国家自然科学基金项目(编号:11873007);国家自然科学基金项目(编号:62175234)。

摘　　要：为实现大口径望远镜的高精度成像,加工过程中需对主镜进行轴向支撑以及侧向支撑,而液压多点支撑作为一种轴向支撑方式,其优势在于可很好地卸载反射镜的重力及磨头带来的加工压力的同时,也方便调整反射镜的姿态。设计了一种万向球铰式液压支撑单元,通过理论推导,得出滚动膜片的结构参数和工作介质液体特性是影响轴向刚度的主要因素。进一步通过搭建液压支撑单元的轴向刚度测试平台,对液压支撑单元的密封性、刚度和刚度分散性进行了测试。结果显示在一定时间内,液压回路的压强变化很小,并在20 min后压强趋于稳定。并从初始压强、气泡含量以及下压速度3个方面测试了影响液压支撑单元轴向刚度及分散性的实验,测试结果显示初始压强提高可提高支撑单元的轴向刚度并降低轴向刚度分散性;当下压速度为0.4 mm/min时,轴向刚度最高,其分散性最小;初始气泡含量越高,支撑单元的轴向刚度越低,两者关系近似反比例函数。提出了一些提高支撑单元的刚度及降低刚度分散性的措施,对卸载反射镜加工及使用中反射镜的支撑单元结构设计提供了一定的参考意义。In order to achieve high-precision imaging of large-diameter telescopes,the main mirror needs to be axially supported and laterally supported during processing.As an axial support method,hydraulic multi-point support has the advantage of being able to unload the mirror well.At the same time,it is convenient to adjust the posture of the mirror while the processing pressure brought by gravity and grinding head.A universal spherical hinge hydraulic support unit was designed.Through theoretical derivation,it was concluded that the structural parameters of the rolling diaphragm and the liquid properties of the working medium were the main factors affecting the axial stiffness.Furthermore,by building the axial stiffness test platform of the hydraulic support unit,the tightness,stiffness and stiffness dispersion of the hydraulic support unit were tested.The results show that within a certain period of time,the pressure change of the hydraulic circuit is small,and the pressure tends to stabilize after 20 minutes.And the experiments that affect the axial stiffness and dispersion of the hydraulic support unit are tested from the initial pressure,the bubble content and the pressing speed.The test results show that the increase of the initial pressure can improve the axial stiffness of the support unit and reduce the axial stiffness dispersion.When the pressing speed is 0.4 mm/min,the axial stiffness is the highest,and its dispersion is the smallest.Additionally,the higher the initial bubble content,the lower the axial stiffness of the support element.And the relationship between the two is approximately an inverse proportional function.Some measures to improve the stiffness of the support unit and reduce the stiffness dispersion is proposed,which provides a certain reference for the unloading mirror processing and the support unit structure design of the mirror in use.

关 键 词：液压支撑单元 轴向刚度 刚度分散性 

分 类 号：TH137[机械工程—机械制造及自动化]