磁流变均匀研抛工具的设计及实验分析

Design and experimental analysis of magnetorheological finishing tool for uniform

磁流变研抛时采用圆柱形永磁铁作为磁场发生装置存在“边缘效应”缺陷,且研抛时不同直径区域上的研抛速度不一致,导致研抛时材料去除不均匀,研抛区域较小.为提高研抛效果,研制了新型的磁流变研抛工具,并进行了理论分析.使用条形永磁铁组合作为磁场发生装置,利用永磁铁的“边缘效应”与“叠加效应”构建了线形增强磁场;并使用等效磁荷法拟合研抛间隙-磁场强度曲线,根据不同研抛区域的研抛速度确定磁场强度,逆向求解研抛间隙,对永磁铁表面进行切割,构建径向均匀的Preston材料去除函数;最后,进行了磁流变研抛对比实验.结果显示,相较于圆柱形永磁铁研抛工具,设计的研抛工具不仅增大了研抛面积,并可实现较大范围的材料均匀去除.

In magnetorheological finishing,the cylindrical permanent magnet was used as the magnetic field generator,which had the defect of"edge effect",and the finishing speed in different radial areas was not consistent,resulted in uneven material removal and small finishing area.In order to improve the finishing effect,a new type of magnetorheological finishing tool was developed,the theoretical analysis and experimental research were carried out.The strip permanent magnet combination was used as the magnetic field generator,and the linear enhanced magnetic field was constructed by using the"edge effect"and"superposition effect"of the permanent magnet.Then,the equivalent magnetic charge method was used to fit the finishing gap-magnetic field intensity curve,and the magnetic field intensity was determined according to the finishing speed of different finishing areas.The finishing gap was solved reversely,and the surface of the permanent magnet was cutted to construct a radial uniform Preston material removal function.Finally,a comparative magnetorheological finishing experiment was carried out,the results showed that compared with the cylindrical permanent magnet finishing tool,the designed finishing tool could not only increase the finishing area,but also achieve a wide range of material uniform removal.