Study On Complex Surface Construction And Simulation Machining Of Mold

With the continuous improvement of industrial automation,automatic processing technology is also in constant innovation.Curve and surface machining is a difficult problem in machining industry,but there are a lot of curve and surface structures in aerospace,automobile and mould fields.Therefore,how to process curve and surface quickly and accurately is a key problem in the current machining technology field.In this paper,a curved surface mold of an enterprise is taken as the research object.By analyzing the structure of the mold and studying the construction method of complex curved surface,the numerical control machining program of the mold is developed and simulated.Provide complete mould processing technology and procedure for enterprises to guide their mould production and processing.In this paper,the complex surface in the model is firstly separated and fitted,and the cubic curve and bicubic surface are constructed on the basis of NURBS basic principle.Then three axis and five axis numerical control simulation machining are carried out on the constructed theoretical surface respectively,and error analysis and comparison are made.Finally,the numerical control simulation machining of the whole model is studied.(1)convert the two-dimensional drawing of the mold into a three-dimensional model,separate the complex surface of the mold from the overall model,and import the data coordinates on the surface of the surface obtained from ANSYS;Using the principle of least square method,programming in MATLAB,in the fitting tool to fit the surface.In this way,the complexity of the surface is analyzed and the value points of NURBS are obtained more accurately.(2)Use NURBS bicubic surface construction technology for surface reconstruction.Through the selection of parameter direction,the determination of node vector and the process according to the control vertices of inverse calculation of boundary conditions,in order to get the type of value point coordinates for the data,using the MATLAB programming to NURBS curve constructed cubic curve,also similarly to the other direction for operation,the last of the free surface is constructed by applying the method of the masked NURBS double three times.(3)Based on the constructed double cubic profile as the theoretical surface,the method of contour cutting was adopted for the three-axis CNC machining and the simulation effect was obtained.Five-axis numerical control simulation machining is carried out by using the method of curved area driving and the simulation figure is obtained.The errors between the two simulated machining surfaces and the theoretical surfaces are analyzed respectively.Through the comparison of error data,the advantages of the five-axis machining method compared with the three-axis machining method in the surface machining process and the influence rule of the nominal size of parts on the error in the simulation machining process are obtained.(4)Contour milling method is adopted to carry out numerical control simulation machining of the whole mold.Through rough machining and finishing for many times,the simulation effect diagram of numerical control machining of the whole mold is obtained,and the tool path and equation are generated.