Research On Tool Path Optimization In Flank Milling Of Undevelopable Ruled Surface

In the field of mechanical processing,as the structure of various types of parts becomes more and more complex,the requirements for machining accuracy are becoming higher and higher and the application fields are becoming wider and wider,how to process complex curved parts has become a hot issue.Traditionally,ball-milling cutters are often used for point milling of complex curved surfaces,which are widely used,but the surface consistency of the processed parts is poor,and this method has low processing efficiency.Aiming at this problem,this paper builds a surface model by studying the geometrical characteristics of the design surface,that is,the undevelopable ruled surface,based on this,and at the same time,it deeply studies the flank milling tool position algorithm.From the geometric point of view,the optimization model of machining error is given to reduce the machining error of parts.The main research contents and achievements of this paper are as follows:1.Through in-depth analysis of the existing key technologies and research status of flank milling for undevelopable ruled surface,we have a deep understanding of flank milling.The basic principles of flank milling,B-spline curve and surface knowledge and the basic theory of the ruled surface in differential geometry are learned and introduced.The different types of tools were analyzed.and finally,a conical tool was selected,which laid a solid theoretical foundation for subsequent model construction and tool path optimization.2.Using NURBS related knowledge,the shapes of undevelopable ruled surface from three angles of known boundary surface equations,boundary curve control vertices and boundary curve data points are constructed.The data points can be transformed into the case of known design surface boundary curve control vertices through the inverse algorithm.Based on the CAD shape of the ruled surface in MATLAB software,the normal vector at each point is calculated and the corresponding distance is offset along its direction.The offset surface shape of the ruled surface can be obtained.3.Compared with cylindrical cutter,the flank milling of conical cutter is more general.The single point offset method and the two-point offset method are studied by using a conical cutter.Keeping the first point unchanged at the end point of the straight generatrix,each uniform discrete point on the straight generatrix is used as the second point of the two-point offset,respectively,and the error of the flank milling process is calculated,and finally the second point under the optimal error is obtained.4.Using a conical cutter,the entire undevelopable ruled surface is geometrically decomposed.Each tool position is used to characterize a single sub-area.Based on the two-point offset method to determine the initial tool position,the flank milling machining model is established based on the mapping curve,and the immune particle swarm optimization algorithm is introduced to solve the objective function in the model to obtain the optimized tool location.5.Since the surface has been decomposed in the previous optimization,the global least squares method is needed to further optimize the tool path,so that the flank milling machining error is further reduced.The effectiveness of the algorithm is verified by simulation and experiments comparing the machining errors before and after optimization.In summary,this paper studies the construction of part surface model and the optimization of flank milling error during the process of undevelopable ruled surface milling.The model construction of three types is given,and based on this,from the traditional and intelligent algorithms,to optimize the machining errors of flank milling for undevelopable ruled surface.