Study On The Five Axis NC Machining Method Of Human Mandible

With the continuous development of modern medical image processing theory and modern medical image medical engineering technique,medical image processing technique and visual image processing technique have been deeply integrated,and have become an important part of scientific research in the field of visualization.In recent years,the solid model reconstruction of human skeleton has been extensively studied in the field of modern medical engineering technique.Meanwhile,reverse engineering has become a new way of human skeleton model reconstruction,and it has shown more and more great application potential.On the other hand,NC(Numerical Control)machining is an essential part in the process of entity model reconstruction.In recent years,some institutions at home and abroad have made rapid progress in multi-axis NC technique,especially five-axis NC machining technique,which has become an advanced machining technique integr ated with precision high-speed machining technique,servo control technique and computer control automation technique,and has been widely used in many engineering fields.In this project,the idea of reverse engineering is used to reconstruct the three-dimensional of the human mandible,and achieve the NC machining of the human mandible aluminum alloy material model by using the five-axis NC machining technique.Specifically,the main research content is divided into the following parts:In view of the asymmetry of the human mandible surface,the ultra-thin characteristic in individual places and the difficulty of modeling and machining,a method using reverse engineering technique is adopted to reconstruct the three-dimensional digital model of human mandible.In this part,the EXAscan laser scanner is used to collect the point cloud data of the mandible surface,and then,the three-dimensional point cloud data is converted into the polygon network model and the NUBRS surface model.Finally,the three-dimensional digital model is exported to STL format file for subsequent processing.In this project,the Cimatron E software is used to achieve the NC programming and simulation of human mandible.Then,the expected accuracy of machining result and NC codes that meet the machining requirement are gotten,so as to ensure the accuracy and rationality of the machining result.Furtherly,the milling force model of ball head cutter is established and the modal analysis and static analysis are conducted respectively.Then,a specific machining scheme is proposed,which can improve the quality of human mandible NC machining process effectively.In view of the asymmetry structure of the human mandible surface and the ultra-thin characteristic in individual places,a variable NC machining method for the aluminum alloy model of the human mandible is proposed.In general medical engineering practice,the human mandible model is made of carbon material,while the aluminum alloy material is lighter in weight,higher in strength,stronger in corrosion resistance and heat resistance,and thus has superior performance.In this project,in order to conform to the development trend of modern materials,that is,materials light-duty,and meet the requirements of production efficiency,profile quality and model accuracy of the human mandible in engineering practice,aluminum alloy material is selected as the machining material of this project.And then,based on the above,a variable speed NC machining method of hum an mandible aluminum alloy material model based on the five-axis NC machining technique is proposed.Subsequently,the machining results are analyzed and the effectiveness of the method is verified.Finally,the research contents and innovative achievements are reviewed and summarized,and the next research plan in the future is looked forward.