The Theoretical And Experimental Research On The Material Removal Of Constant Force Abrasive Belt Grinding And Polishing

The blade is the core component of the key equipment such as engine,turbine,compressor in aviation industry and electric power industry.Because of its bearing bad physical and chemical effect in the work environment,the blade should be ensured to have high precision profile and excellent surface quality in the manufacturing.And abrasive belt polishing is one of the processing methods which is often used in the blade finishing.At present,many domestic and foreign research institutions and companies have developed a large number of grinding and polishing machine tools using constant grinding and polishing force in the process for complex workpieces,and choose the grinding force as one of the process parameters of polishing the complex surface workpieces.Based on the constant force grinding and polishing machine tool,and make the remove polishing mechanism of polishing as the theory to polish the complex surface workpiece.Based on the Preston equation and the Hertz contact theory,the relative mathematical expressions is established,which could describe the relationships of between the material removal profile,the maximum material removal depth and the polishing force,line speed,feed speed when the complex curved surface of workpiece is polished by a contact wheel belt polishing tool.Through the experiments,the value of constant of the Preston equation can be acquired.By the simulation,the material removal relationship among the process parameters is visual with the analysis and elaboration of the simulation curves.In order to study the material removal rules under constant force grinding and polishing,a control system of constant pressure pneumatic should be built.By using the laws of thermodynamics,ideal state equation and Newton's second law and other related knowledge,the pneumatic control system mathematical model of constant pressure is deduced.By using off-line system identification technology and System Identification toolbox in MATLAB software and M sequence that is chosen as the input signal,parameters of the mathematical model of the pneumatic system have been obtained.Also the closed-loop system was verified to be stable.Based on the obtained mathematical model of the dynamic system,the PID controller,fuzzy PID controller and the corresponding simulation program have been established.What`s more,two control strategies of dynamic system were compared in the application by simulation.Two kinds of control modes were programmed by LabVIEW software,and found that the fuzzy PID control could achieve a more ideal control curve for nonlinear system through experimental.After that,the accuracy of the value of output force in the control system was verified by using the Kistler dynamometer,the results showed that the grinding force of this control system could be exported accurately as desired output.By using LabVIEW software,the pneumatic grinding and polishing control software was developed,which could realize the collection,transmission,processing and control of the signal data in the process of grinding and polishing.The material removal experiments were carried out to verify the accuracy of the material removal profile and the maximum removal depth model.Finally,the accuracy of the model was proved by comparing the experimental results with the simulation curves.