Force Test Analysis Of Vertical Vibratory Finishing Machine Based On Empirical Mode Decomposition

As a precision finishing method,surface finishing technology can effectively improve the surface quality.It can improve the wear resistance,contact stiffness,fatigue strength and corrosion resistance of the parts.Vibratory finishing technology depends on collision,scratching,extrusion and friction between workpiece and media to achieve finishing process of parts.Because of the advantages of simple equipment,high processing efficiency,wide application range,low processing cost and green environmental protection,vibratory finishing has been widely used in highend equipment manufacturing fields such as aerospace,energy efficient vehicles,rail transit and weapons manufacturing.At present,vibration finishing is lack of quantitative research,in this paper,the vertical vibration finishing equipment is taken as the subject investigated.EDEM simulation software is used to simulate the finishing process and using dynamic force sensor to build media force testing platform.Testing and analysis of dynamic force signals at different positions under fixed mode,then design validation experiment.The main research of paper is as follows:1.The normal contact force at different positions of workpieces with five kinds of fixed finishing process conditions is analyzed by EDEM software,and the distribution law of the normal contact force between the media and the workpiece surface in vertical vibration finishing is obtained;2.Comprehensive analysis of the advantages and disadvantages of current vibration signal processing methods and their application scope.Empirical mode decomposition algorithm is selected according to the characteristics of the vibration signal studied in this paper.At the same time,the simulation of MATLAB proves that empirical mode decomposition has the characteristics of self-adaptability,orthogonality and completeness,which can effectively extract the frequency characteristics of the vibration signal;3.Building a test platform based on vertical vibratory finishing equipment,using piezoelectric dynamic force sensor to test the force of media during finishing process.The collected signal is decomposed by empirical mode to achieve the noise reduction and reconstruction of the original signal.The average force acting on the workpiece surface during the stable processing stage is extracted,and the general law of the average force acting on the workpiece surface during the stable processing stage in the vertical vibration finishing process is obtained.4.Design verification test with the different finishing position as a parameter variable.The processing effect of each finishing position was compared with the surface roughness of the workpiece,then compared with the average force on the workpiece surface by the media.Finally,the relationship between the force of the media and the machining effect in the vertical vibration finishing process is obtained.In this paper,the force of media in vertical vibration finishing is tested by dynamic force sensor and the empirical modal algorithm is used to extract the characteristic frequency of the vibration signal to achieve noise reduction and reconstruction.The average force of the media in the processing is effectively extracted,which fills in the blank of quantitative research on the dynamic parameters of the vertical vibration finishing process.