Research On Reverse Design Method Of Complex Curved Surface

Reverse engineering as an important means of advanced manufacturing technology, which is divided into five key technologies such as data acquisition, data preprocessing, data block and the surface reconstruction, CAD model construction, and rapid prototyping. Using reverse engineering, we can reconstruct the solid model of the product parts; we also can modify and re-design of the prototype. Through reverse engineering, we can establish and master our own product development and design technology in order to innovative design. It is an important tool to raise the technological level of China's manufacturing industry. Taking the typical complex curved surface of the turbine blade as an example, this paper does a research on the complex curved surface of reverse design process and realized the integration of design and manufacture in the reverse engineering.Firstly, the paper introduced the digital measurement principle and method, and tells the different feature between the characters of contact measurement and non-contact measurement. And then it discusses the process of the three coordinate measuring machine measuring surface. On the basis of the existing methods of measurement, we put forward mining point of the longitudinal vertical measurement solutions. The program not only can improve the speed of sampling sites, but also benefit to improve surface reconstructing precision at later. Finally, we got a digital point cloud data of the blade by the GLOBAL 575-type coordinate measuring machine.Based on the principle of curved surface reconstruction and after the data preprocessing, we reconstruct the three-dimensional model of the blade through the point - line - surface reconstruction method by CATIA V5 software. Meanwhile, we solve the coordinate measuring machine error radius compensation issues by using surface offset command.On the basis of blade surface reconstruction, we analyzed machining technologies of the blade and then determined the cutting parameters and feed path in the machining process. Using UG NX 7.0 of CAM function module and combining the structure features of blades and characteristics of four-axis machining center, we got the tool path and completed the four-axis machining of turbine blades and simulate machining. Then, considering the existing processing conditions, we carried on the post-processing and generated NC code for CNC machining by choosing appropriate processing parameters. Finally, we got the blade entities by using CNC machining centers and wire cutting.