Research On The Automatic Polishing Technology And Process Parameters Optimization

In recent years,the advanced machinery manufacturing has promoted rapid development of the national defense industry. Currently,the demand of mechanical parts with complex curved surface to the defense industry products is increasingly urgent. Furthermore, due to the special causative environment,most of products require these mechanical parts to achieve a higher surface quality. At this time, polishing becomes an essential processing operation. However, due to the complexity of the surface, the problem of interference and collision occurs easily.This results that polishing process is still finished manually. Based on this, we carried out basic research on automatic polishing technology in this paper. The main contents of this paper include the following four parts.Firstly, after a profound understanding of the automatic polishing status, we constructed automatic polishing system based on five-axis machining center DMU60. DMU60 can achieve multi-axis synchronous, so it can satisfy the automatic polishing requirements of complex curved surface. Meanwhile, elastic polishing tools we selected can meet the requirements of flexible contact between the polishing disk and the workpiece. Therefore, the system we constructed can meet the requirements of following polishing experiments.Secondly, we analyzed the material removal characteristics in the polishing process based on the finite element method. According to specific polishing tool and work-piece material, we established contact model. Based on the contact model, we carried out finite element analysis and obtained the pressure distribution characteristics in the contact area. Then, we constructed removal depth model. Meanwhile, in order to guarantee uniform depth of material removal, we obtained the optimal step-over size by using the superposition effect of tool path.Thirdly, we conducted polishing experiments on the platform we have constructed. First of all, we formulated machining process scheme, determined the process parameters and planned polishing trajectory. Then, we carried out polishing experiments on planar and curved parts. We obtained surfaces with high-precision mirror effect.The experimental results showed that processing program we formulated is feasible. Lastly, we completed experiments with respect to the influences of process parameters on surface roughness. Through experiments we obtained the variation tendency of Ra with the variation of polishing parameters.Finally, we established surface roughness prediction model based on the response surface method and completed the process parameter optimization. In this section, we designed the four factors and five levels experiment according to the principle of CCD. After completed ANOVA of the experimental data, we established a second-order regression prediction model on surface roughness. Based on the model, we analyzed impacts of each process parameter on surface roughness. Meanwhile, we conducted process parameter optimization and obtained the optimal combination of parameters.