Analysis Of Vibration Reduction And Suppression Of Suction Device And Deployment Device Of Bottom-pasting Machine

Packaging equipment is the foundation of packaging industry.The vibration phenomenon in packaging equipment in many cases will lead to shortening of the life of structural parts and reducing the performance of the reliability.How to reduce the vibration of the structure of equipment has gradually become the focus of research.In this thesis,the suction device,deployment device and the frame of the paper and yarn compounded bag bottom-pasting machine are taken as the research objects,and the vibration reduction optimization scheme is determined according to the dynamic analysis and experimental test to achieve the purpose of vibration reduction and vibration suppression.The main research contents are as follows :(1)Establish the dynamic model of the suction device and deployment device.Firstly,the working principle,basic structure and running state of the suction and deployment device are described.Then,Lagrange function and D ’Alembert principle are used to analyze the forces of the suction arm and the deployment arm respectively,and the dynamic models of the suction arm and the deployment device are established according to the results of the mechanical analysis.According to the dynamic model,the motion velocity of the suction arm and the mass distribution of the deployment arm have great influence on the vibration of the suction and deployment device respectively.(2)Determine the vibration reduction scheme of the suction device.Firstly,the finite element model of the suction device is established and the modal analysis is carried out,and the measuring points are selected by the effective independent-average acceleration amplitude method.Then,when the initial motion velocity is determined by vibration test,the test signal of the measuring points of the suction device,and the noise reduction of the acceleration signal is processed by wavelet decomposition and reconstruction.Finally,the experimental signals of the same measuring point at different speed of the suction arm are compared.It can be seen from the comparison results that the acceleration signal amplitude can be effectively reduced and the first-order natural frequency can be increased when the velocity of the suction chuck is adjusted to half of the initial velocity at the moment of collision of the suction device to achieve the purpose of vibration reduction of the suction device.(3)Determine the vibration suppression scheme of the deployment device.Firstly,the finite element model of the deployment device is established and the modal analysis is carried out,and the measuring points are selected by the effective independent-average acceleration amplitude method.Then,the acceleration signal of the measuring points of the deployment device before changing the mass distribution is determined by vibration test,and the noise reduction of the acceleration signal is processed by the non-local mean method.Finally,by comparing the acceleration signals before and after the change of deployment arm mass distribution,it can be seen from the comparison results that the amplitude of acceleration signal is reduced and the number of shocks caused by the hinge gap is reduced under the steel-aluminum mass distribution scheme,which effectively improves the overall vibration suppression effect of the device.(4)Optimize the geometric parameters of the frame.Firstly,the design parameters of the frame to be optimized are determined and the initial finite element model is established according to the design parameters.Then,Latin hypercube experimental design method is used to sample the optimized parameters,and the sample points are substituted into the finite element model for modal analysis.The obtained modal frequency and sample points are used to build a Kriging model to replace the finite element model,so as to improve the computational efficiency of frame optimization.Then,minimizing the rato of frame mass to the first-order natural frequency as the objective functions,the water cycle optimization algorithm is used for iterative optimization.Finally,according to the optimal design parameters,the finite element model is re-established and the modal frequency,rack deformation and stress are compared with those from the initial finite element model.The results show that the method based on Kriging model and water cycle algorithm has a certain effect in the frame optimization design.