Research On Flexibility Control Of Polishing Head And Polishing Technology Based On Rigid Granular

Along with the progress on science and technology and the continuous development of manufacturing industry, mold is widely used day by day particularly in high-tech fields such as aerospace, automotive manufacturing etc. Mold manufacturing and design level has become an important symbol to measure a country's industrial development level. However, finishing machining method on the surface of mold is mainly manual polishing nowadays, which has a low removing efficiency, long processing cycle and unstable quality. In order to solve these problems, a new flexible polishing technology that is adjustable flexibility polishing technology based on rigid granular was presented in this dissertation. Adjustable flexibility polishing technology based on rigid granular is a continuation of flexible polishing technology such as bonnet tool polishing and magnetorheological fluid polishing, which is a advanced polishing technique with high precision and high efficiency. It is also a kind of mold free-surface polishing technology with strong innovation and practicality, which worth to explore actively and expand. While this polishing technology were used in polishing metal mold, the workpiece surface can be precisely controlled by polishing with high material removal efficiency, which has a significant meaning in rough polishing mold. The contents of the study include the following parts:(1) A model regarded ideal iron sphere as study object was established after the analysis on mold polishing technology and application situation, with the combination of characteristics of polishing technology, based on granular mechanics, electromagnetic principle and physical model of dipole. Then the model was modified by shear test.(2) A robot polishing system was developed applied in polishing free-form surface of mold based on modified mechanical model. The system uses Motorman MOTOMAN-HP20 as a carrier of polishing tools. An automated polishing system was established through controlling the robot to achieve the automatic polishing trajectory planning. Compared with traditional polishing method, this system can realize flexible polishing on different types of surface. Because this system uses flexible technology, the polishing head stiffness can be adjusted along with the magnetic field strength in real-time, and different polishing trajectories can be realized by controlling the robot. The experimental results show that the polishing technology is practical, with high removal efficiency.(3) A flexible polishing prototype based on rigid granular was designed after the analysis of machine function and movement requirements in order to spread the polishing technology application on mold industry. Some key technology were also analyzed and researched.In this dissertation, the polishing principle and application of magnetic granular was also discussed which provide a good foundation for further research.