Research On Mechanical Polishing Process For Parts With Curved Surface Based On The Material Removal Mechanism

Polishing is a complex process under various polishing conditions. How to control the process parameters to keep surface material quickly and evenly removed and improve the surface quality, is a key problem for automatic mechanical polishing system. Currently, automatic polishing mainly adopts constant speed at a constant polishing spacing. For surface, a constant feed speed can make material removal depth of different polishing point under or over, resulting in the surface material removal is not uniform; Constant polishing spacing can cause excessive and lack polishing, affecting surface quality. In this paper, based on the polishing material removal mechanism, polishing process and trajectory planning for parts with curved surface are researched to resolve these problems.First of all, based on Preston equation and Hertzian contact, verify the relationship between polishing process and material removal profile and material removal depth of the contact point for parts with curved surface by simulation and experiment, providing key technical foundation for the process planning of automatic mechanical polishing system.Secondly, On the basis of orthogonal test and regression analysis method, study the relationship between roughness for parts with curved surface with the process parameters including polishing force, polishing tool speed, feed rate and the equivalent radius of curvature; Based on the genetic algorithm, it is concluded that the polishing process parameters of the initial polishing point to get the best surface roughness.Then, speed adaptive model is proposed for parts with curved surface with uniform material removal. Guaranteeing material removal depth of each polishing contact point equal, speed adaptive model is put forward that feed speed changes with the change of equivalent radius of curvature. It is verified by contrast experiment. Based on adaptive speed model, a single polishing path bandwidth variation rule is further studied, which established the foundation for the polishing of trajectory planning.Finally, polishing trajectory planning algorithm is designed based on the coverage area map. To ensure polishing material removal uniform for the whole parts with curved surface, based on the material removal profile model, polishing spacing of plane and curved surface is analyzed, and through the test, the influence of polishing spacing on surface roughness is investigated. Put forward polishing path planning algorithm based on the coverage map to avoid the excessive and lack polishing and verify the feasibility of the path planning algorithm by simulation.