Aviation industry efficient CNC machining programming system integration case

　　Customer introduction

　　An aircraft manufacturing company, affiliated to China Aviation Industry Corporation, is China's aircraft research and production base and aviation industry backbone enterprise.

　　The company has strong scientific research and production technology strength and strong cold and hot processing capabilities and means, with strong physical and chemical testing, measurement, ad hoc, flight test and digital management and manufacturing capabilities.

　　Background of the project

　　CNC machining refers to the process of machining parts on CNC machine tools. As a commonly used molding method, it is widely used in aviation, aerospace, shipbuilding and mold industries. With the development of society, people's demands for productivity are getting higher and higher, and the problems faced by traditional CNC machining are gradually exposed. Figure 1 is a survey of the time-consuming processing of a typical part by a traditional foreign website. result. The investigation shows that the roughing process takes 57 time, the finishing time is 127, the polishing time is 86, the finishing and polishing process accounts for more than 80% of the entire processing process, and the subsequent large amount of manual casting is required, which is inefficient and greatly extended. Product production cycle and manufacturing costs.

Figure 1 Traditional CNC machining time-consuming distribution

　　Aiming at the problems exposed by traditional CNC machining, domestic and foreign scholars and enterprise manufacturers have done a lot of targeted research and achieved certain results. Among them, the NC machining algorithm based on wide-line theory developed by Beihang is in a leading position. Compared with the traditional CNC machining technology algorithm, the method can improve the processing efficiency by 2-10 times, and the surface processing quality is also improved obviously without any overcutting phenomenon. However, the algorithm only supports standard CAD data formats such as igs, and does not support CATIA model data. The CAD modeling tools used by user units are mainly CATIA. When applying the CAM algorithm, the programming technician needs to perform additional CAD model data conversion work. The process is cumbersome and easily causes data loss and loss of precision, and affects the actual processing accuracy. The actual application of the algorithm in the user unit is greatly limited.

　　Project Objectives

　　Based on the advantages of the wide-line algorithm and its problems in the practical application of the user unit, the project will integrate the CATIA platform with the CAM system through the CATIA open CAA secondary development method and related interface design, and realize the CAM system on the CATIA platform. The smooth application greatly promotes the application degree of the algorithm in the user unit, thereby greatly improving the overall technical strength and competitiveness of the user unit.

　　solution

　　Based on the background of user needs, Anto conducted detailed requirements analysis and business process (as shown in Figure 2), and formed corresponding solutions.

Figure 2 business process

　　The software is mainly divided into two parts: one part is CATIA platform, which is used for 3D model construction, machining model definition, surface dispersion and tool path display, etc. The other part is CAM system, which mainly performs tool strategy definition and tool path calculation. The project is based on the CATIA CAA component architecture idea, using C++ language programming, combined with the algorithm program application process, the main program of the algorithm is integrated with the CATIA platform. Through the back-end database, all the data in the algorithm application process is managed uniformly, so as to realize the flexible exchange and accurate transmission of data between the CATIA platform and the CAM algorithm, and finally realize the integration and application of the algorithm program in the CATIA platform, as shown in Fig. 3.

Figure 3 software implementation logic flow

　　User revenue

　　At present, the project results have been successfully promoted and applied in the user units, and have been highly praised and highly evaluated by various application departments. The main benefits are reflected in the following aspects:

　　■ The digital model preparation process is simple and efficient

　　In the process of product digital model design, because the design model is often complicated, some complex processing surfaces are often expressed by multiple surface patches. Due to the CAM algorithm requirements, the former technician needs to fit the stitched surface piece into a regular parameter surface, and the fitting process is extremely complicated, involving a large number of operation steps, which seriously restricts the application and promotion of the algorithm. Through the project results program, the technician can simply define the input, and the program background automatically completes a large number of cumbersome geometric operations, greatly simplifying the process and workload of the technician, thereby greatly improving the application and application efficiency of the software. Figure 4 shows a comparison of the before and after fitting of a complex surface.

Figure 4 A comparison of a complex surface fit

　　■ The software application process is clear and the application is good

　　On the basis of fully understanding the user's business needs and business processes, Antto adopts a “top-down” functional module design for the software. The user application process is clear and easy to understand, easy to operate, and user experience is good.

　　■ The processing efficiency is doubled

　　At present, the project results have been promoted and applied in the user's manufacturing workshops. Through the investigation of the processing results, it is found that compared with the traditional processing algorithms, the surface finish of the processed parts processed by the results of the project is obviously improved, the processing line spacing is wide, the subsequent throwing amount is significantly reduced, and the processing efficiency is improved. It has been significantly improved, greatly improving the overall technical level and competitiveness of user units in the industry.