Research On Checking And Optimizing Algorithms Of Tool Path For Five-axis NC Machining

Complicated curved surfaces are widely used in the manufacturing industries of medical devices,vehicles,aerospace,art,etc.with their superior modeling technology.In response to the increasingly high requirements for CNC machining of complex surfaces,traditional three-axis CNC machine tools can no longer meet the increasingly sophisticated precision requirements.Five-axis CNC machining has begun to move towards the stage of the times,and five-axis machining can go smoothly with its higher degree of freedom.To complete curved surfaces that cannot be machined by traditional three-axis machine tools,five-axis CNC machining technology has begun to develop day by day.As the most important part of five-axis CNC machining,tool path planning has also become an important research topic at home and abroad.This paper systematically introduces the development history of CNC machining technology and the development status of tool path planning for complex curved parts.Through the research of several hotspots in trajectory planning,a series of research and experiments have been carried out to address the shortcomings of traditional methods.In terms of step length planning,A Cutter-Contact Point adjustment algorithm based on Accurate Chord Error checking is proposed;in terms of row spacing,A tool path stitching algorithm based on row bandwidth prediction is proposed.And through NX10.0 and VERICUT software,the algorithm of this paper and the comparison algorithm were processed by cutting simulation,which verified the correctness of the algorithm.The specific research contents are introduced as follows:The development process of NC machining is introduced in detail,and the research status of tool selection,the topology of tool path curve,step length and row bandwidth in tool path planning is deeply studied,and then the main research content of this paper is determined.This paper analyzes the kinematics of common five-axis NC machine tools,deduces the differential geometry characteristics of free-form surface in detail,and introduces the related concepts and parameter calculation in tool path planning.A Cutter-Contact Point adjustment algorithm based on Accurate Chord Error checking is proposed: In order to improve the machining accuracy of traditional equal chord error step length method,this paper adds accurate chord error checking calculation based on the traditional equal chord error step length method,and then uses one-dimensional linear search algorithm to adjust the location of the next Cutter-Contact Point.A tool path stitching algorithm based on row bandwidth prediction is proposed: In order to improve the processing efficiency of the traditional Isoparametric method,according to the known tool path curve and row bandwidth,the position of the next tool path curve is preset by fitting and interpolation methods,and the effective splicing of the tool path is established Range,and then adjust the position of the subsequent tool path curve by determining the positional relationship between the left edge of the adjustment tool contact and the effective splicing range.The parametric surface is modeled by NX 10.0 software,and the NC program of tool path in rough machining,semi finish machining and finish machining stages is generated.The NC program is imported into VERICUT software,and the five axis NC machining center model is built by VERICUT software.The tool path of this algorithm and the finish machining algorithm are simulated,and the simulation results are analyzed.