复杂曲面反求设计方法的研究

发布时间：2018-05-30 00:44

本文选题：逆向工程 + 数据测量　；参考：《华北电力大学》2011年硕士论文

【摘要】：反求工程是先进制造技术的重要手段,分为数据获取、数据预处理、数据分块与曲面重构、CAD模型构造以及快速原型等五大关键技术。利用反求工程可重构产品零件的实体模型,也可对原型进行修改和再设计。通过逆向工程,建立和掌握自己的产品开发设计技术,进行产品的创新设计,是提升我国制造业技术水平的重要手段。本文以典型的复杂曲面零件汽轮机叶片的反求过程为例,研究了复杂曲面的反求设计过程,实现了反求工程中设计与制造的一体化。首先介绍了数字化测量的原理与方法,分析了接触式测量与非接触式测量的特点,探讨了接触式三坐标测量机测量曲面的过程。在现有测量方法的基础上提出了竖直纵向采点的测量方案,该方案不仅提高了采点速度,也利于以后提高曲面重构精度。最后利用GLOBAL 575型三坐标测量机得到了叶片的数字化点云数据。在曲面重构的原理基础上,经过数据预处理后,采用CATIA V5软件,通过点-线-面的曲面重构方式,重构了叶片的三维模型。利用曲面偏置命令,解决了三坐标测量机的半径补偿误差问题。在叶片曲面重构的基础上,分析了叶片的加工工艺,确定了叶片加工的切削参数和走刀路线。利用UG NX 7.0的CAM功能模块,结合叶片的结构特点及四轴加工中心的特点,规划了刀路轨迹,完成了汽轮机叶片的四轴加工,并进行了加工仿真。结合现有加工条件,通过选择合适的加工参数,对加工过程进行后置处理,生成了数控加工NC代码。最后利用数控加工中心及线切割完成了叶片的实体加工。
[Abstract]:Reverse engineering is an important means of advanced manufacturing technology, which includes five key technologies: data acquisition, data preprocessing, data partition and surface reconstruction, CAD model construction and rapid prototyping. The prototype can also be modified and redesigned by using the solid model of reconfigurable parts in reverse engineering. Through reverse engineering, it is an important means to improve the technological level of our manufacturing industry to establish and master their own product development and design technology and carry out product innovation design. In this paper, the reverse design process of complex curved surface is studied, and the integration of design and manufacture in reverse engineering is realized by taking the reverse process of turbine blade of typical complex curved surface part as an example. Firstly, the principle and method of digital measurement are introduced, the characteristics of contact measurement and non-contact measurement are analyzed, and the process of measuring curved surface by contact CMM is discussed. Based on the existing measurement methods, a vertical sampling point measurement scheme is proposed, which not only improves the sampling speed, but also improves the precision of surface reconstruction in the future. Finally, the digital point cloud data of the blade are obtained by using GLOBAL 575 CMM. Based on the principle of surface reconstruction, after data preprocessing, the blade 3D model is reconstructed by using CATIA V5 software and the method of point-line-surface reconstruction. The radius compensation error of CMM is solved by using curved surface offset command. Based on the reconstruction of blade surface, the machining technology of blade is analyzed, and the cutting parameters and cutting path are determined. Based on the CAM function module of UG NX7.0, combined with the structural characteristics of the blade and the characteristics of the four-axis machining center, the path of the cutter path was planned, the four-axis machining of the turbine blade was completed, and the machining simulation was carried out. According to the existing machining conditions, NC codes of NC machining are generated by selecting suitable machining parameters and postprocessing the machining process. Finally, the solid machining of blade is finished by NC machining center and wire cutting.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH122;TP391.7

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