Research On CAM System For Five-Axis Denture Processing

With the rapid development of society,the demand for dentures is growing.Due to the high processing precision,fast generation efficiency and good processing quality of the five-axis CNC machining system,the five-axis denture machining CAM system is gradually becoming the mainstream of denture processing equipment.At present,most denture processing companies use foreign denture processing systems,but they are expensive and cannot respond quickly to customer needs.Therefore,it is of great significance to research and develop a localized five-axis denture processing CAM system.In this thesis,the key technical requirements in the development of five-axis denture processing CAM system,the research on the visualization technology of denture numerical control model,the research on the tool path generation algorithm of denture machining,and the NC code(5-axis)which can be recognized by the fiveaxis CNC machine tool.CNC machine tool processing post processing technology research.In the visualization technology of denture numerical control model,the format and structural characteristics of the denture numerical control model file are analyzed.The edge adjacency relationship other than vertex is established for the subsequent tool position trajectory generation,and the structure and algorithm are designed to realize the digital model of denture Visualization;generating the required point coordinate information and normal vector information for the knife contact,using the triangular method vector information,calculating the triangle vertex method vector information,and then implementing the normal vector of any point on the edge of the triangle according to the linear interpolation concept Calculation;for the operation of the denture model required in the actual denture machining process,the model is designed to be operable,and the functions of translation,scaling and rotation of the model are realized.In the aspect of the tool path trajectory algorithm of denture processing,the pre-processing method was studied,the establishment of the foundation,the generation of the connecting rod and the determination of the excess cutting amount were completed.For the processing characteristics of the denture,the tool and cutting suitable for the denture machining were selected.The method of obtaining the contact point of the denture machining knife based on the section method is given.The calculation method and the detailed algorithm flow chart are given.According to the tool point and the tool contact calculation formula,the initial tool position trajectory is obtained.The error and five-axis NC machining nonlinear error are formed.The optimal line spacing is determined based on the residual height.The optimal step size is determined based on the error analysis.The optimal tool contact is selected and the tool path trajectory is optimized.In the post-processing technology of five-axis CNC machine tools,the mathematical model of the AB five-axis CNC machine tool was established for the characteristics and actual needs of the five-axis CNC machine tool.The post-processing algorithm is designed,and the specific flow chart,coordinate transformation algorithm and specific formula are given.The nonlinear error caused by the machining of five-axis CNC machine tool is analyzed and solved,and a detailed correction scheme is given.Based on the above research,the overall scheme of CAM system for the needs of five-axis denture processing is designed in this thesis,and the visualization and operability of the digital model of denture is further realized.To lay the foundation for the further development of the fiveaxis denture processing CAM system.