Dynamic Simulation And Parametric Optimization Of Vibration Absorption Boring Bar

With the development of mechanical manufacturing industry, the domains related to manufacture are becoming more and more widely. In the meantime, the requirements about processing quality and efficiency are improving steadily due to the intense market competition. Hole machining, especially the processing of the hole with large depth and small diameter, are very common in various processing methods. If boring operations are used to machining this kind of deep hole, the boring bar must be spindle for the special processing environment. Once the length-diameter ratio of boring-bar is more than four times, the stiffness of it will drop quickly. Consequently, the vibration of the boring-bar will become severe, and then the processing quality of hole is difficult to guarantee. Sometimes, severe vibration will lead to shut down. Therefore, how to reduce the vibration of the boring-bar with large length-diameter ratio is already a problem we urgently need to solve.Traditionally, in the study of boring process, the mathematical model for the vibration absorption system of boring-bar is established firstly and then the dynamic equation is listed. The vibration performance analysis of boring-bar is realized through mathematical methods totally. But this method is computation complexity and inefficiency. In this thesis, the finite element method, which can solve complex engineering problem, is adopted to analyze the vibration performance of boring-bar with vibration absorption system. At the same time, the general finite element software Ansys is applied to help calculate the problem. Through this software, dynamics simulation of boring-bar can be done and the calculated results can help the designer predict the vibration characteristics, and then relevant factors which affect the vibration performance can be confirmed. Through optimizing these factors, the damping effect of boring-bar reach peak. Obviously, this means not only can shorten the time for development, but also can reduce product development costs and reduce the waste of material.In this research, through consulting and comparing many advanced vibration absorption structure, the boring-bar with built-in dynamic vibration absorption designed by Sandvik company is selected as the main reference object. Taking into account the actual manufacturing situation of domestic industry, some local improvement is done to the structure. In the dynamics analysis of vibration absorption system, firstly, use the mathematical theory to get the initial value of reducing vibration system parameters. Secondly, establish the finite element model of built-in dynamic vibration absorption boring-bar in software Ansys. Then use software Ansys to do the simulation of dynamics analysis. On the basis of this step, the optimal function of Ansys can be use to optimize the parameters of the vibration absorption system and get the optimal parameters of vibration absorption system that we have designed.This analysis can be as the basis for the design and improvement of built-in dynamic vibration absorption boring-bar, and can solve the problem that we can't get a accurate result of boring-bar's dynamical characteristics using a traditional means. This may be the important guidance for the research of built-in dynamic vibration absorption boring bar.