基于环形抛光法若干确定性控制问题的研究
文献类型：学位论文
| 作者 | 焦翔 |
| 学位类别 | 博士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 朱健强 |
| 关键词 | 环形抛光 大口径光学元件 极限精度 面形控制 平衡态 |
| 其他题名 | Study on Several Deterministic Control Issues for Continuous Polishing |
| 中文摘要 | 高精度光学平面在现代光学与光电子学领域有重要应用，环形抛光（Continuous Polishing, CP）技术是获得高精度与低粗糙度光学表面的重要方法，在大口径精密光学元件抛光中有无可替代的地位。虽然环形抛光机目前应用很广泛，设备也很精良，但对于稳定、可控地加工出高精度光学元件还远远不够。美国、法国等许多国家也都在进行环形抛光理论及模型的研究。目前限制大口径光学元件抛光效率的重要因素之一是面形控制，大口径光学元件的抛光具有很大的不确定性，目前仍以经验加工为主，缺乏理论指导。对于面形控制问题，多年来许多工作者进行了相关研究，这些研究主要集中在几个方面：1.根据Preston方程和运动学原理研究面形变化；2.接触应力；3.温度分析；4.抛光中的面形检测技术；5.针对大尺寸工件或特殊形状、特殊材料工件的工艺改进，包括精度控制和快速收敛技术。前人的工作对解决实际问题有重要意义，但有些根本性的问题未得到解决，主要包括：抛光系统组成之间的相互作用、极限精度、系统的状态问题和系统的稳定性等问题。这些问题的提出和解决对环形抛光技术的发展和深入研究有深远的意义。此外，还有些具体的技术问题，例如环形抛光中的温差对大口径光学元件面形的影响、抛光中非理想受力对工件面形的影响，环形抛光技术用于抛光球面等。 环形抛光系统对环境变化和加工参数非常敏感，微小的改变都可能对加工结果带来严重的影响，这使得在环形抛光机上开展实验具有相当的复杂性及不稳定性，致使规律难以把握，经验数据不能长期有效，不同的生产者有不同的加工技巧等。环形抛光领域整体存在生产的盲目性，缺少行之有效的理论指导。 本文首先对环形抛光系统进行了理论研究，建立了系统的数学模型，深入研究了环形抛光系统的状态和调节特性。在对系统状态研究的基础上，提出了工件的最高精度问题，并且深入分析了最高精度的影响因素，为加工精度的提高提供了重要的理论指导；对系统面形调节特性的研究，证明了平衡态的存在，这是环形抛光系统稳定的理论基础，并系统地分析了平衡位置的影响因素，提出了环形抛光机中的“杠杆原理”，对实际生产具有重要的指导意义。环形抛光系统通常用于高精度平面加工，但根据其特性，同样可应用于大曲率半径球面的高精度抛光，本文对环形抛光技术抛光大曲率半径球面进行了探讨。 对环形抛光原理的研究只反应了系统面形贴合后的状态，不能分析系统面形变化的动态过程。动态过程的意义在于可以反应存在面形误差的工件对抛光盘的影响，决定了面形调节方法和加工效率。所以之后本文建立了环形抛光系统的动态模型，根据动态模型研究了工件与抛光盘面形从不贴合到贴合的过程，得出了在平衡态抛光，工件面形误差对抛光盘面形影响很小这一结论，这体现了系统平衡态的重要性，奠定了环形抛光机连续高精度抛光的理论基础，之后提出了平衡态抛光工件的技术方案。 以上建立了环形抛光系统的理论体系。本文之后对系统温度特性进行了研究，研究结果表明，即使在低速抛光情况下工件上下表面也会产生较大的温差。提出了合理搭配工艺参数和对工件非加工面绝热两种温差控制方法。通过采用控制变量法和对工件绝热抛光法进行测温实验验证了方案的可行性，为高精度面形加工奠定了基础。另外，本文提出了抛光时倾覆力矩对工件面形的影响，指出倾覆力矩是引起不同尺寸工件面形不一致的原因，并提出了有效的解决方案。 本文的意义在于，建立了环形抛光系统的理论体系，开展了一系列尚未报道的工作，拓宽了环形抛光技术的研究手段，对国内外大口径高精度平面的抛光具有重要的指导意义。此外，文中对环形抛光系统的研究方法，对其他古典抛光或传统抛光均有指导意义。 |
| 英文摘要 | The high precision optical flat surfaces possess important applications in modern optics and optoelectronics. Continuous polishing (CP) is an important method to obtain high precision and low roughness optical surface, which is irreplaceable in processing of precision large aperture optical components. Although CP machines are widely used today and they become more and more excellent, but they are far from stably and controllably processing high precision optical components. Many countries such as American and France are also in study of CP theories and models. Up to now, one of the important reasons for limiting the polishing efficiency of large aperture optical components is the controlling of the surface figures which are highly indeterminate. The experiences play more important roles than the theories in surface figure controlling. Many researchers studied on this field from many years ago and their researches focused on the several below aspects: 1. Studying on the surface change based on the Preston equation and kinematics; 2. Contact stress; 3. Temperature analysis; 4. Surface figure measurement in polishing process; 5. Technical improvement for large or special shape workpieces or special material workpieces in control of surface figure accuracy or fast convergence. The works done by former researchers have important significance for solving practical issues, however, some basic problems haven’t been solved. The problems mainly include the interaction of the parts of the polishing system, limit accuracy, the system condition and stability and so on. The raising and solving of the problems are important for the development and further research for CP. In addition, there are some specific technical questions such as the influence of the temperature difference and the non-ideal force to the surface figure and the applying to polishing spherical surface. The CP system is highly sensitivity to the environment and processing parameters, tiny change may cause severe impact to the result. So the experiment results is complicated and unpredictable, which makes the regularity hard to grasp, the empirical data can’t be long-term effective or different operators have different skills. The CP processing is blindness and lack of theoretical direction. First, the theoretical research has been done in this paper. The condition and the regulating characteristic of CP system is well learnt on the basis of the mathematical model. Then the issue of the limit accuracy has been raised and the influencing factors have been deeply studied, which is important for the accuracy improvement. The existence of the equilibrium state is proved in the process of the regulating characteristic research, which is the theoretical basis of the stabilization of the CP system. The factors which can influence the equilibrium position has been analyzed, then the lever principle for the CP has been proposed which is quite useful for actual production. The CP system is commonly used for flat polishing, however, according to the characteristics, it can also be used for polishing large radius spherical surface. So polishing spherical surface with CP machine is discussed in this paper. Study of the theory of CP can only discover the condition after the parts of the system completely matched but not the process the surfaces matching. The dynamic process is meaningful because it can reflect the influence the polishing surface with error to the pitch lap, which may decide the adjust method and work efficiency. So the dynamic model is built up, and according to the model, the process the surfaces from not fit to completely fit is studied and the conclusion that the effect the workpiece surface with error to the lap is very small when the CP machine works at equilibrium state. The phenomenon implies the importance of the equilibrium state and lay the foundation of the CP machine continuous high precision polishing. Then the technical proposal of equilibrium polishing is proposed. The above content is the system info of the CP. This paper also researches on the temperature difference of the system. The results show that the temperature difference exists between the two sides of the workpiece even the CP machine rotates very slowly. Two ways that rational combine the technological parameters and make the non-polishing surfaces of the component thermal isolate are given. The methods are verified by control variables experiments and adiabatic polishing experiments and lay the foundation of the high precision polishing. Furthermore, this paper also points out the influence of the capsizing moment to the surface figure and it’s the main reason that causes the figure inconformity of different size components, then, this paper gives the solution. The significances of this paper are that the system info of CP is built up and a series of work not yet been reported is carried out, the research approaches are broaden. They are important guidance to the high precision polishing of large aperture optical components domestic and overseas. Furthermore, the research methods in this paper also indicates the direction to the other traditional polishing technology. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15935]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 焦翔. 基于环形抛光法若干确定性控制问题的研究[D]. 中国科学院上海光学精密机械研究所. 2015. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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