红外材料非球面透镜的超精密磨削加工关键技术研究

发布时间：2018-01-21 23:46

本文关键词： 红外材料非球面透镜砂轮修整超精密磨削声发射信号监测　出处：《哈尔滨工业大学》2016年博士论文　论文类型：学位论文

【摘要】：红外透镜是红外光学系统中用来传输、折射、入射光线的光学元器件,是红外成像和制导系统中的关键元件。非球面透镜能够减小甚至消除由球面透镜在准直和聚焦系统中带来的球差以及其他的一些光学像差,也可减少光学系统中光学元件的数量,简化光学系统的结构,降低光学系统的复杂性,使得光学系统更小和更轻。因此,非球面红外透镜在航空航天、电气、土木工程、医学、汽车等诸多领域都具有非常重要的应用价值和广阔的应用前景。目前,非球面透镜大批量生产的主要途径为古典研磨抛光,存在加工效率低、产品一致性差的特点。而超精密磨削加工具有加工效率高、产品一致性好、工艺稳定性强的特点,是非球面红外透镜精密成形的新技术之一。本课题以红外材料单晶硅和多光谱CVD硫化锌为研究对象,以实现红外成像与制导技术关键光学元件的Φ150mm球面、Φ93.5mm非球面透镜的确定性、低损伤、超精密磨削加工为目的,主要进行以下研究工作:分析现有的非球面磨削加工方法,结合实际设备条件,选择适用的磨削加工方法。理论分析非球面轮廓对磨削加工过程中砂轮与工件几何接触弧长、未变形切削厚度、残留高度以及各种误差的影响,通过理论分析与实验研究相结合的方法确定出最终磨削加工非球面的实验方案。结果表明,垂直磨削法中的砂轮与工件几何接触弧长的变化和未变形切削厚度均较小,可以获得更小的残留高度,砂轮误差对工件表面质量的影响更小,实验后获得的表面质量更高、更稳定。在上述加工方法研究的基础上,依据不同的磨削加工需求,面向于粗磨和精磨非球面用圆弧形金刚石砂轮,提出两种基于旋转绿碳化硅磨棒的在位精密修整技术。针对不同的修整方案,分析修整系统中磨棒的形状误差和砂轮的对刀误差对金刚石砂轮修整形状精度的影响规律以及相应的解决方法。通过工艺实验,研究修整参数对金刚石砂轮修整效果的影响规律,优化相应修整工艺参数。修整后砂轮的圆弧轮廓度显著提高,圆跳动误差显著降低,为红外材料非球面透镜的超精密磨削加工提供了工具保障。研究了磨削纹路对加工后工件表面质量的影响规律,提出基于优化磨削工艺参数匹配关系的磨削纹路抑制策略,为磨削加工过程提供了工艺参数匹配关系的选择依据。通过磨削加工实验选择有利于红外材料非球面透镜超精密磨削加工的砂轮性能参数;基于正交实验方法进行超精密磨削的工艺参数优化实验,为大尺寸非球面的超精密磨削加工提供工艺支持;最后完成了大尺寸红外材料非球面透镜的超精密磨削加工。加工后,Φ150mm口径单晶硅球面透镜和Φ93.5mm口径的多光谱CVD硫化锌非球面透镜由在位测量设备获得的两面面形精度PV均为0.5μm左右,表面粗糙度Ra均小于5nm,为非球面红外透镜的确定性、低损伤、超精密加工奠定工艺技术基础。修整和磨削加工过程的信号监测技术,可减少砂轮修整及磨削状态中不必要的时间和磨料消耗,提高整体加工效率,降低生产成本。最后,针对圆弧形金刚石砂轮的修整与非球面红外透镜的磨削加工过程,搭建了基于旋转声发射传感器的声发射信号采集系统。分析处理了修整过程的原始声发射信号,并提取修整过程的特征值信号,实现了旋转磨棒修整法中修整结束特征阈值的判别。探索了加工工艺参数对非球面粗磨和精磨加工中信号特征值的影响程度,以及加工表层质量与声发射信号的关系,为实现砂轮修整及磨削加工的在线监测提供了技术支撑。
[Abstract]:Infrared lens is used to transmit the infrared optical system, refractive index, optical components of incident light, is the key element and the infrared imaging guidance system. The aspheric lens can reduce or even eliminate the aberration caused by the spherical lens in collimating and focusing system as well as some other optical aberrations, also can reduce the number of optical elements in optical system the simplified structure of the optical system, reduce the complexity of the optical system, the optical system is smaller and lighter. Therefore, aspheric lens infrared in aerospace, electrical, civil engineering, medicine, and has very important application value and broad application prospects of the car and many other areas. At present, the main way of aspheric lens mass production for the classical polishing, has low processing efficiency, product consistency and difference. Ultra precision grinding has high machining efficiency, good product consistency The characteristics, process stability, is one of the new technology of aspheric lens infrared precision forming. The infrared materials of multi spectral CVD monocrystalline silicon and zinc sulfide as the research object, in order to achieve with 150mm spherical key optical components and infrared imaging guidance technology, uncertainty, 93.5mm diameter aspheric lens and low damage, ultra precision for the purpose of grinding, mainly for the following research work: analysis of non spherical surface grinding of the existing methods, combined with the actual condition of the equipment, selection of grinding method for aspheric profile. Theoretical analysis of grinding wheel and workpiece in grinding process of contact arc length, undeformed chip thickness, residual height and the influence of various errors, methods through the combination of theory analysis and experiment research to determine the final non spherical grinding experiment scheme. The results show that the grinding wheel grinding method in contact with the workpiece geometry The change of arc length and undeformed chip thickness are small, can get smaller residual height, smaller grinding error influence on workpiece surface quality, surface quality after the experiment obtained higher and more stable. Based on the above method, according to the different needs of the grinding processing, for coarse grinding and fine for grinding circular arc diamond wheel aspheric surface, puts forward two kinds of rotating rod mill in green silicon carbide based on precise dressing technique. According to the different effects of dressing, dressing system analysis tool setting error grinding rod shape error of grinding wheel and diamond grinding wheel dressing shape precision and the corresponding solutions. Through experiments, influence rule of dressing parameters on the diamond dressing effect, optimization of process parameters. After finishing the corresponding trimming arc wheel profile degree is greatly improved, circular runout error is significantly reduced, as Provides tools to protect the ultra precision grinding of spherical lens, infrared material was studied. Influence of grain grinding surface quality of the workpiece after machining, grinding lines optimization suppression strategy is proposed based on the relationship between grinding parameters, grinding process, select the basis for providing the parameters matching relationship. Through the experiment of grinding selection for infrared material non spherical lens grinding wheel performance parameters of ultra precision grinding; optimization of experimental parameters of ultra precision grinding based on orthogonal experimental method, for large aspheric surface ultra precision grinding process to provide support; finally completed the ultra precision grinding of aspheric lens of large infrared materials. After processing, multi CVD spectra of zinc sulfide with 150mm aperture spherical lens and the aperture diameter of 93.5mm silicon non spherical lens surfaces obtained by in situ measurement equipment The shape precision of PV were about 0.5 m, surface roughness Ra is less than 5nm, to determine the aspheric lens, infrared low damage, lay the foundation technology of ultra precision machining. Signal monitoring technology of dressing and grinding process, can reduce the unnecessary time and consumption of abrasive wheel dressing and grinding. To improve the machining efficiency, reduce the production cost. Finally, according to the grinding process of circular arc diamond wheel dressing and aspheric lens set rotating infrared, acoustic emission sensor acoustic emission signal acquisition system based on the analysis of the treatment. The dressing process of the original acoustic emission signal, and extract features of the dressing process value signal is realized the rotary grinding stick discrimination dressing method in end. To explore the threshold characteristics of influence of process parameters on non spherical coarse grinding and fine grinding of signal eigenvalues, and machining surface quality The relationship between the quantity and the acoustic emission signal provides a technical support for the on-line monitoring of grinding wheel dressing and grinding.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG580.6

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