超声振动辅助砂带磨削技术的研究

发布时间：2018-02-20 18:49

本文关键词： 超声振动砂带磨削磨削轨迹磨削力表面质量　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：超声振动辅助砂带磨削是一种新型加工技术,与普通砂带磨削相比,具有磨削力小、磨削热少和加工表面质量高等优点,具有宽广的市场应用前景。通过对该研究领域国内外相关文献的总结分析,对径向超声振动辅助砂带磨削机理进行了系统的研究,在试验研究的基础上,确定了径向超声振动辅助砂带磨削的运动轨迹特征;建立了径向超声振动辅助砂带磨削的磨削力数学模型;分析了磨削力特性;并对砂带单磨粒材料去除过程进行了仿真分析;通过试验对试件加工表面质量进行了验证。基于理论解析与有限元相互印证的方法设计超声变幅杆。通过变幅杆的振幅放大试验,表明:控制频率与功率值可以实现对振幅的精确控制,发现在理论谐振频率时,输出端振幅达到最大,远离理论谐振频率时,输出振幅减小,并与功率成正比关系。超声振动辅助砂带磨削的过程是多磨粒切削试件材料的过程。根据超声振动辅助下砂带磨削的运动轨迹特征,推导出单磨粒运动轨迹方程,建立单磨粒运动轨迹仿真模型,分析结果表明:超声振动辅助砂带磨削的单磨粒磨削路径长度长于普通磨削,且磨削路径为一条正弦曲线,周期振荡次数与频率成正比,与磨削速度成反比。研究构建了普通砂带磨削与超声振动辅助砂带磨削下单磨粒的磨削力数学模型,设计了砂带磨削力验证实验,研究表明:超声振动辅助砂带磨削的磨削力要低于普通磨削,磨削力随磨削深度、振动振幅的增加而增大,随主轴转速的提升而降低。基于试件的材料本构模型、断裂准则、接触与摩擦理论建立单磨粒磨削的仿真模型,分析结果表明:超声振动辅助下的单磨粒磨削切向力、法向力要低于普通磨削,在不同磨削参数下,单磨粒磨削力的变化规律与磨削力数学模型的预测结果一致,磨削温度随磨削深度、磨削速度、振动振幅的增加而增高,且超声振动作用下的磨削温度降低。通过进行超声辅助砂带磨削与普通磨削加工表面质量的对比试验研究,发现超声振动作用下的加工表面质量优于普通磨削。普通磨削后的试件加工表面呈现出平行的划擦条纹,条纹深度深浅不一,而超声振动辅助磨削后的试件加工表面呈现出紧密相邻的鳞甲状花纹,排列有序,且深度小于普通磨削的条纹深度;普通磨削下的试件加工表面粗糙度呈现梯度排列,有比较明显的边界线,且边界线趋于平行,超声振动辅助磨削下的试件加工表面粗糙度分布无序,没有明显边界情况,粗糙度值较低,高粗糙度数值分布范围减小;试件加工表面粗糙度值随着磨削深度的增加而增大,随着主轴转速、砂带粒度、振动振幅的增加而减小,但当振动振幅过大时会造成加工表面粗糙度值的增加。且超声振动辅助磨削下试件加工表面粗糙度值都明显的小于普通磨削的磨削表面粗糙度值。
[Abstract]:Ultrasonic vibration assisted abrasive belt grinding is a new processing technology, which has the advantages of less grinding force, less grinding heat and high surface quality. It has broad market application prospect. Based on the summary and analysis of domestic and foreign literatures in this field, the mechanism of radial ultrasonic vibration assisted abrasive belt grinding is studied systematically. On the basis of experimental study, The moving track characteristics of radial ultrasonic vibration assisted abrasive belt grinding are determined, the grinding force mathematical model of radial ultrasonic vibration assisted abrasive belt grinding is established, the grinding force characteristic is analyzed, and the removal process of single abrasive material is simulated and analyzed. The machined surface quality of the specimen is verified by experiments. Based on the theoretical analysis and finite element method, the ultrasonic amplitude-varying rod is designed. The results show that the control frequency and power can control the amplitude accurately. It is found that the output amplitude reaches the maximum when the theoretical resonance frequency is at the output end, and the output amplitude decreases when the resonance frequency is far away from the theoretical resonance frequency. The process of ultrasonic vibration assisted abrasive belt grinding is the process of multi-abrasive material cutting. According to the characteristics of the motion track of belt grinding under ultrasonic vibration, the motion trajectory equation of single abrasive particle is derived. The simulation model of single abrasive motion trajectory is established. The results show that the length of grinding path of ultrasonic vibration assisted abrasive belt grinding is longer than that of ordinary grinding, and the grinding path is a sinusoidal curve, and the number of periodic oscillations is proportional to the frequency. In this paper, the grinding force mathematical model of ordinary belt grinding and ultrasonic vibration assisted belt grinding is established, and the grinding force verification experiment is designed. The results show that the grinding force of ultrasonic vibration assisted abrasive belt grinding is lower than that of ordinary grinding, and the grinding force increases with grinding depth and vibration amplitude, and decreases with the increase of spindle speed. The simulation model of single abrasive grinding is established by contact and friction theory. The results show that the tangential force and normal force of single abrasive grinding assisted by ultrasonic vibration are lower than those of common grinding, and under different grinding parameters, The variation rule of single abrasive grinding force is consistent with the prediction result of grinding force mathematical model. The grinding temperature increases with the increase of grinding depth, grinding speed and vibration amplitude. The grinding temperature is reduced under ultrasonic vibration. The surface quality of ultrasonic assisted abrasive belt grinding is compared with that of common grinding. It is found that the machined surface quality of ultrasonic vibration is better than that of common grinding. After ultrasonic vibration assisted grinding, the machined surface of the specimen is closely adjacent to the scale pattern, arranged in order, and the depth is less than the depth of the common grinding stripe, the surface roughness of the specimen after ordinary grinding shows a gradient arrangement. There is obvious boundary line, and the boundary line tends to be parallel, the roughness distribution of the specimen machined by ultrasonic vibration assisted grinding is disordered, there is no obvious boundary condition, the roughness value is lower, and the numerical distribution range of high roughness is reduced. The surface roughness increases with the increase of grinding depth, and decreases with the increase of spindle speed, belt size and vibration amplitude. However, when the vibration amplitude is too large, the machining surface roughness value will increase, and the surface roughness value of ultrasonic vibration assisted grinding is obviously lower than the grinding surface roughness value of common grinding.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG580.6;TG663

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