深孔加工颤振抑制装置设计与研究

发布时间：2018-02-27 10:48

本文关键词： 深孔加工颤振抑振装置磁流变液　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：在深孔的加工过程中,振动的形式一般存在三种:自由振动、强迫振动和颤振(自激振动)。一般情况下,自由振动或者强迫振动采用消除外部激振源的方法可进行抑制,该方法甚至可以达到消除的效果,然而颤振却难以抑制,长久以来都困扰深孔加工技术的发展。在深孔加工的过程中,颤振的发生不仅降低加工效率、刀具损坏、机床加速磨损,而且对加工人员的健康带来不利影响。全面掌握深孔加工过程中颤振产生的机理并对颤振进行有效抑制,对改善加工质量以及降低废品率具有重要的现实意义。针对目前加工深孔过程中颤振难以抑制的问题,本文研究并设计出基于磁流变液机理的深孔加工颤振抑制装置实现对颤振的抑制。首先,建立深孔加工过程的动力学模型并对其稳定性进行分析,由再生型颤振产生机理可知在加工深孔的整个过程中颤振主要是加工中前后两次振痕的相互作用,并且受到切削系统加工的临界条件影响。随后,分析研究主轴转速与深孔加工过程中稳定性的关系,得出变速切削可以有效的抑制颤振;分析切削系统刚度变化对深孔加工稳定性的影响,得出该方法可以起到与变速切削抑振相同的效果,得出深孔加工颤振抑制装置的设计基本原理,为装置设计提供理论基础;分析切削系统阻尼与深孔加工稳定性的关系,得出改变阻尼在颤振抑制上的作用并不明显。其次,分析研究磁流变液材料、磁流变效应的产生机理和磁流变液减振器的原理,完成了深孔加工颤振抑制装置的结构设计以及控制策略的优化选择。建立安装深孔加工颤振抑制装置后深孔加工过程的动力学模型,并对应用该装置后进行抑制效果和参数优化的仿真分析研究。通过对仿真结果的分析,表明采用控制磁流变液磁场的强度进而控制切削系统的固有频率,可以达到通过控制切削系统的固有频率抑制颤振的目的。最后,在深孔加工过程中,通过应用深孔加工颤振抑制装置可以较好的抑制颤振,并且克服了变切削速度和变阻尼抑制方法的不足。
[Abstract]:In the machining of deep holes, there are generally three forms of vibration: free vibration, forced vibration and flutter (self-excited vibration). In general, free vibration or forced vibration can be suppressed by eliminating external excitation sources. This method can even achieve the effect of elimination, but flutter is difficult to restrain, which has been puzzling the development of deep hole machining technology for a long time. In the process of deep hole machining, the occurrence of flutter not only reduces the machining efficiency, but also the tool damage. The machine tool accelerates the wear and tear, and brings the adverse effect to the health of the machiners, fully grasps the mechanism of the flutter in the deep hole machining process and effectively restrains the chatter. It is of great practical significance to improve the quality of machining and reduce the rate of waste. In view of the problem that flutter is difficult to restrain in the process of deep hole machining, In this paper, the flutter suppression device for deep hole machining based on the mechanism of magnetorheological fluid is studied and designed. Firstly, the dynamic model of deep hole machining process is established and its stability is analyzed. According to the mechanism of regenerative flutter, the flutter is mainly the interaction of two vibration marks in the process of machining deep hole, and it is affected by the critical condition of machining system. The relationship between spindle speed and the stability of deep hole machining is analyzed. It is concluded that variable speed cutting can effectively suppress chatter, and the influence of stiffness change of cutting system on the stability of deep hole machining is analyzed. It is concluded that this method can have the same effect as variable speed cutting to suppress vibration, draw the basic design principle of flutter suppression device for deep hole machining, provide the theoretical basis for the device design, analyze the relationship between the damping of cutting system and the stability of deep hole machining, and analyze the relationship between the damping of the cutting system and the stability of the deep hole machining. It is concluded that the effect of changing damping on flutter suppression is not obvious. Secondly, the mechanism of magnetorheological effect and the principle of magnetorheological shock absorber are analyzed and studied. The structure design of the flutter suppression device for deep hole machining and the optimal selection of control strategy are completed. The dynamic model of the deep hole machining process after the installation of the deep hole machining chatter suppressor is established. The simulation results show that the intensity of magneto-rheological fluid magnetic field is controlled and the natural frequency of cutting system is controlled. The flutter can be suppressed by controlling the natural frequency of the cutting system. Finally, in the process of deep hole machining, the flutter suppression device can be used to suppress the flutter. And it overcomes the deficiency of variable cutting speed and variable damping suppression method.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG52

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