Research On Surface Smooth And NC Machining Interference Analysis Methods

With the development of aerospace、automobile、mold and other fields、numerical control(NC)technology is widely used in the manufacturing of complex surface parts.The NC machining technology based on reverse engineering has obvious advantages in production cycle and research work still need to be carried out in theory.In this dissertation,the scanning data of complex mold surface is taken as research object.Aiming at the unfairness problem caused by the unorganized noise point in scanning data,a global fairing method of surface data is proposed.And in order to solve the problem of global interference and local interference during NC machining using toroid cutter,an interference analysis method is proposed.At last,effectiveness of this method is verified by machining experiment.The main work is as follows:(1)Overall fairing of reconstructed surface.Aiming at slice data of surface point cloud,a roller method to fair curve is presented to deal with the noise point in slice data to ensure smooth of surface slice profile.On this basis,a roller method of fairing surface is carried out.In order to ensure the smooth between slices,smooth the surface along another parameter direction,thus the overall fairing of surface slice data to machining surface is completed.(2)Research on global interference analysis in NC machining.On the basis of tool path planning for NC machining,box technology is used to analyze the global interference between machined surface and tool post.The geometric model of interference analysis is established to calculate the maximum interference and to correct interference tool position,and then the cutter location point is re-planned.(3)Research on local interference analysis in NC machining.By calculating the minimum distance between the tool and the complex surface in the tool path of NC machining,determining whether there is an interference point on the surface being machined and calculating the maximum interference.According to the interference point on the surface and the interference to correct interference tool position,and then get the non-interference tool path.(4)NC machining experiments.Taking the NC machining of shoe surface as an example to program the post-processing program,then carry out the finishing experiment on the NC machine tool,analyzing the experimental results and verificating the effectiveness of the interference analysis and the interference correction method.