【作者】 赵凯；

【导师】 贾振元；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2015， 博士

【摘要】 高速飞行器天线是典型的高性能零件,不仅具有优良的电气性能,而且必须满足一定的强度和刚度要求,是飞行器实现定位导航、遥感测控和微波通讯等功能的关键零件,该类天线通常由工程塑料基底表层覆盖金属图案制造而成。随着应用需求的发展,在要求该类天线满足更高电气性能要求的同时还要实现轻量化、小型化。因此,新型超高性能复杂曲面跨尺度图案天线应运而生,该新型零件表层图案特征尺寸跨度大(数十微米～数百毫米)、形状复杂、几何精度要求高(微米级)、边缘质量要求高(主要为轮廓度)。鉴于该类零件的以上特点,导致现有加工技术制造效率较低、精度难以保证,严重制约了我国高速飞行器的整体性能提升。随着高速飞行器的快速发展,该新型天线需求量增加与加工效率低的矛盾也日益突显,因此,研究工程塑料复杂曲面零件表层跨尺度图案的高精高效数字化加工方法具有重要的意义。在对复杂曲面零件表层金属图案加工中,近年来新兴发展的激光加工、微细铣削等技术为该类零件表层跨尺度图案的精密制造提供了有益的借鉴。因此,本文在分析现有单一工艺手段优缺点的基础上,提出了激光加工与微细铣削组合的加工工艺,即借助高速数控激光加工的高效率,实现大面域金属覆层的高效去除；借助微细铣削加工的高精度,实现微小区域及宏观图案边缘的精密制造。针对目前仍制约该方法工业应用的关键性工艺难题,本文开展了一系列研究工作,包括虑及机床动态特性的激光高效精密加工技术、微细铣削毛刺抑制方法和多工艺组合五轴联动数控加工装备研制等,并基于以上研究内容开展了典型零件——超高性能复杂曲面跨尺度图案天线的加工实验,具体研究内容如下：(1)零件表层图案具有复杂变曲率特征,受机床动态性能制约,激光高速加工中进给速度存在时变性,易诱发激光烧蚀去除量不均、轨迹轮廓误差大,加工后图案边缘质量下降等问题,需开展虑及机床动态特性的复杂图案激光高效精密加工技术研究。通过激光单因素加工试验研究,为最佳工艺参数组合的选取提供了依据。基于热能平衡原理,建立了以恒定去除量为约束的激光能量与进给速度关联模型,研究了激光输出能量根据实际进给速度自适应调整的控制算法,并结合提出的保证复杂变曲率图案轮廓精度分区域变速度加工方法,形成了虑及机床动态性能的激光加工进给速度与激光功率协同控制技术。通过以上研究,确保了宏观图案边缘的光顺一致,为微细铣削清边加工奠定基础。(2)面向激光热烧蚀去除机理制约下的局部微小图案制造困难、大面域激光高速加工图案存在“斜坡”状边缘与热影响区,采用微细铣削进行微小图案的精密制造与大尺寸图案边缘修整。同时虑及金属覆层与基底结合力弱、刀具尺寸小和被加工材料延展性好等因素,开展微铣加工零件表层图案毛刺抑制方法研究。通过试验研究得到了合理的工艺参数范围及加工策略,并以毛刺尺寸最小为目标,提出了基于二阶响应曲面法的多工艺参数同步优化方法,得到满足图案边缘质量要求的工艺参数组合。此外,研究了基于随形加工原理的零件自由表面切深控制方法,克服了复杂曲面零件存在制造、安装等误差引起的金属覆层切削过量或残留,实现了零件表层图案的高质量制造。(3)提出了“激光大面域高效去除+微铣制造微小图案与清边”复杂曲面表层跨尺度图案加工方法,并基于该方法研制了多工艺组合的五轴联动数字化加工装备。通过将两种工艺手段精密衔接,实现了零件的一次装夹和跨尺度制造。同时,借助数控机床的精密定位功能,提高了复杂曲面零件表层图案的制造精度,保障了该类零件单元和批次的一致性。最后,利用所提出的“激光大面域高效去除+微铣制造微小图案与清边”加工方法与研制的多工艺组合五轴联动数字化加工装备,进行了典型复杂曲面表层跨尺度图案类零件——新型高性能高速飞行器天线的加工实验。所加工的复杂曲面零件表层图案最小特征尺寸150μm,最大特征尺寸20mm,图案的对称度和几何尺寸误差小于±20μm。零件制造结果表明,本文所提出的多工艺组合加工方法与装备能够实现工程塑料复杂曲面零件表层跨尺度金属图案的精密制造。更多还原

【Abstract】 Aircraft antennas are typical high-performance mechanical parts requiring excellent electrical performance as well as high strength and stiffness, which are playing key roles in aircraft performances such as positioning, remote sensing and communication. Generally, these parts can be produced by covering metallic pattern on plastic substrates. As demands for high-performance antennas developed, smaller and lighter parts with higher electrical performance are required. Hence, a new kind of antenna with ultra-high performance produced by covering multi-scale pattern on a complex curved surface emerges. The parts have graphic features with large span, high geometric accuracy (μm) and high quality edge is required. Because of the above characteristics, existing processing methods can hardly meet manufacturing demands due to low precision and efficiency. Therefore, the development of processing methods greatly influences the improvement of aircraft performance, leading to great challenges in processing technologies.With the rapid development of aircrafts, the study of high-precision and efficient CNC machining methods for processing multi-scale pattern on complex curved surfaces is of great significance. In processing the metallic pattern covered on complex curved surfaces, the laser machining method and micro milling technology can be referential for the high-precision manufacturing of such parts. Therefore, base on analyzing the advantages and disadvantages of single method, an innovative processing technology combining laser etching and micro-milling is presented in this article. The combined processing technology realizes the efficient removal of large-area metal cladding due to the high efficiency of laser processing. Besides, the high-precision manufacturing of small areas and the edges of the macro graphics can be achieved with the aid of micro-milling. To solve the key technical problems which still restrict the industrial application of the new method, a series of research work are carried out in this paper. Researches include high precision laser processing technologies considering dynamic characteristics of machine tools, burr controlling methods in micro-milling, and the development of five-axis CNC machining equipment with combined process. In addition, machining experiments for high-performance antennas with complex curved surface covered by multi-scale pattern are machined. Specific contents of the research are as follows:(1) The pattern of antenna parts has characteristics of complex variable curvatures, due to the constraints of machine tool dynamic performance, the feed speed during the process of high-speed laser machining changes continuously. This may lead to uneven removals, large trajectory profile errors and poor edge quality of machining parts after processing. Considering the dynamic characteristics of machine tools, it is necessary to earry out researches for laser processing of complex pattern. In this paper, research experiments for laser processing provide the basis for the selection of an optimum combination of parameters. According to the heat balance principle, a relation model connecting the laser energy and feed speed based on the constraint of constant removal amount is established. Besides, a control algorithm for the adaptive adjustment of the output energy of laser according to the actual feed speed is studied. Moreover, combining with the subregional machining method with variable speeds, a cooperative control technology for the processing feed speed and laser power is developed considering the dynamic performance of machine tools. Through the above research, smooth edges of macro graphic are guaranteed, laying a foundation for the machining process of micro-milling for edge clearing.(2) To solve problems caused by the manufacturing difficulties by high-speed laser machining methods, micro milling is employed to realize the high-precision manufacture and edge finishing of large areas. Considering the small binding force between the metal cladding layer and the substrate, the small size of cutting tools and the good ductility of processed materials, the researches of burr control technologies are carried out. The reasonable range of processing parameters and processing strategy are obtained by experimental studies. Moreover, by setting the minimum burr size as a goal, an optimization method for multi-technological parameters is proposed based on the second order response surface method, processing parameters requirements of the edge quality can be guaranteed by the patterns combination. In addition, a cutting depth compensation method for the free surface of parts based on shape processing technique is studied. Through the above study, the high-quality manufacturing of patterns on surface of parts can be realized.(3) Based on the proposed method "laser machining of large-area+ high-precision manufacturing and edge clearing by micro milling", a multi-technology five-axis CNC machining equipment combining is developed. Through precision connection of these two kinds of processing methods, multi-scale manufacturing can be achieved through one-time clamping. Besides, the manufacturing precision of patterns on complex curved surface can be improved with the aid of the precise positioning function of the CNC machine tools, ensuring the consistency of such parts in the unit and batch.Finally, by using the proposed manufacturing method and the developed five-axis CNC machining equipment, the manufacturing of typical parts is realized. Machining results show that the high-precision manufacture of multi-scale patterns covered on the complex curved surface of engineering plastic parts can be realized by the proposed the multi-technology processing method and equipment更多还原