Research On Design And Performance Of Variable Frequency Damper Alloy Damping Boring Tool

Machinery manufacturing industry is a pillar industry in China's economic construction,which is of great significance to China's economic development and plays an important role in improving the quality of life of citizens.Deep hole processing involving deep hole parts is one of the most difficult types in hole processing,and deep hole parts have very important applications in many fields.Deep hole machining includes deep hole boring.During the process of deep hole boring,due to the limitation of the processing space,it is necessary to use a large aspect ratio boring tool with a long overhang to process the inner surface of the part.The low overall rigidity can easily cause chattering of the process system,which in turn leads to a reduction in the quality and accuracy of the workpiece processing,and it is very easy for the workpiece to fall short of the designed application standard.In order to solve the chattering problem in the process of deep hole boring,in recent years,many scholars at home and abroad have studied this field,and it has become a hot issue in the field of machining.In this thesis,a variable frequency.damping alloy damping boring bar is designed,and some researches are done on the design and optimization algorithms of the absorbing structure of the boring bar.Through theoretical derivation,simulation analysis and experimental research,the design and performance research of variable frequency.damping alloy damping boring bar is completed.The specific research contents are as follows:In order to study the vibration generation mechanism during boring,a dynamic model of the process system was established,and the causes of self.excited vibration were analyzed.The effects of boring barlength.diameter ratio and material dynamics on its vibration were analyzed through simulation,laying a theoretical foundation for the design of variable frequency.damping alloy vibration.absorbing boring bars.Comprehensively compare multiple passive vibration reduction methods,propose a new vibration control method combining damping alloy and dynamic vibration absorption structure,and study the vibration reduction mechanism of these two passive vibration reduction methods.The overall design scheme of variable frequency.damping alloy damping boring bar is proposed,the two.degree.of.freedom dynamic model of the damping boring bar is established,the relevant theoretical analysis of the model and the MATLAB / Simulink simulation analysis are completed.The vibration situation before and after vibration reduction is compared,which verifies the vibration control ability of the vibration reduction boring bar designed in this paper.The optimization method of damping alloy structure is studied,and the possibility of applying modal strain energy algorithm to the optimization of non.uniform damping alloy structure is proposed.Through research,it is found that the structural parameters of the damping alloy are very important for the damping boring bar.Therefore,the influence of the application of the damping alloy on the stiffness,damping ratio and natural frequency of the boring bar should be considered in the design.The feasibility of the modal strain energy method in the optimization of damping alloy structures is verified by comparison with the theoretical calculation results.The non.uniform damping alloy structure optimized by the modal strain energy algorithm,with the same amount of damping alloy,the stiffness and loss factors are significantly higher than the traditional uniform thickness damping alloy structure.The optimization method of dynamic vibration.absorbing structure is studied,and the possibility of applying GA-BP algorithm to the optimization of variablefrequency.dynamic vibration.absorbing structure is proposed.The specific application methods of GA-BP algorithm are studied,including the training array,the normalization of the array,the determination of the neural network structure,and the selection of model parameters.The training array required by the GA-BP algorithm was obtained through simulation analysis.The optimal dynamic vibration absorption structure parameters and the corresponding minimum vibration amplitude were obtained after the calculation.Compared with the simulation analysis results,the accuracy of the optimization results obtained by the GA-BP algorithm is verified.Simulation analysis of common boring bar,damping alloy damping boring bar and variable frequency.damping alloy damping boring bar,including modal analysis and harmonious response analysis.The harmonic response analysis results verify the superiority of the variable frequency.damping alloy vibration.damping boring bar in the range of vibration frequency adaptation,and the division of the optimal frequency of the vibration.damping boring bar is completed.In order to verify that the variable frequency.damping alloy damping boring bar designed in this paper has higher structural damping and the accuracy of simulation modal analysis results than ordinary boring bars,the ordinary boring bars,damping alloy boring bars,and variable Frequency.damped alloy vibration.damped boring bars were subjected to impact response experiments,and the natural frequency,damping ratio and other dynamic parameters of the three boring bars were obtained through parameter identification.In order to verify the vibration.damping performance and adaptability of variable frequency.damping alloy vibration.damping boring bars,the overhung length of the dynamic vibration.absorbing structure was used as a variable,and the steady.state excitation response experiments were performed on the two types of boring bars correspondingto different excitation frequencies.Through boring experiments,the influence of machining parameters on the vibration acceleration of the boring bar was studied.According to the relevant conclusions,appropriate machining parameters can be selected to suppress the vibration in the boring process.Under the same processing conditions,ordinary boring bar and variable frequency.damping alloy vibration.damping boring bar were used for processing,which verified the ability of the vibration.damping boring bar designed in this paper to suppress the vibration and improve the machining quality of the workpiece surface.