带集磁器的吸引式电磁力小管件翻边方法

Attractive electromagnetic force flanging method for smalltube fittings with magnetic field shaper

针对微小铝合金管件电磁翻边工艺,现有方法将驱动线圈置于管件端部外侧,利用双频电流法产生吸引式电磁力实现翻边。然而其翻边能力不强,基于此提出一种带集磁器的吸引式电磁力翻边方法。在现有方法基础上引入集磁器,利用其能够改变磁场位形的特点,优化电磁力分布并增大轴向电磁力,达到增强翻边效果的目的。为验证该方法的可行性,通过搭建管件翻边过程的电磁-结构全耦合有限元仿真模型,对比引入不同集磁器后的翻边效果,同时分析了不同工况对电磁力分布、电磁力密度以及磁场和涡流的影响。得出阶梯型集磁器效果最佳,结果表明,该方法下管件翻边角度从38°增大到90°。进一步分析表明,其磁通密度径向分量和涡流密度环向分量分别增大到164%和135%,作用在管件上的电磁力分布改变,峰值时刻轴向电磁力体密度明显加强,增大到211%。该方法进一步完善了对微小铝合金管件的电磁翻边成形,对拓展电磁成形技术在铝合金管件翻边上的应用具有一定意义。

Aiming at the electromagnetic flanging process for small aluminum alloy tube fittings,the drivingcoil is placed on the outside of the end of the tube,and the dual-frequency discharge current method is used to generatethe attractive electromagnetic force to realize flanging in the existing method.However,its flanging ability is notstrong,under this background,an attractive electromagnetic force flanging method with a magnetic field shaper isproposed.On the basis of the existing method,a magnetic field shaper is introduced,which can change the magneticfield configuration,optimize the electromagnetic force distribution and increase the axial electromagnetic force,so asto achieve the purpose of enhancing the flanging effect.To verify the feasibility of this method,firstly,theelectromagnetic-structural fully coupled finite element simulation model of the tube flanging process was built,and theflanging effects after introducing different magnetic field shaper were compared,and it is concluded that the steppedmagnetic field shaper has the best effect.The flanging process were analyzed under the working conditions withstepped magnetic field shaper and without magnetic field shaper.The results show that the flanging angle of the tubefittings is increased from 38°to 90°compared with the case without the magnetic field shaper.Further analysis showsthat the radial component of the magnetic flux density and the annular component of the eddy current density increaseto 164%and 135%,respectively.The distribution of the electromagnetic force acting on the pipe fittings changes,andthe density of the axial electromagnetic force increases significantly at the peak time,increasing to 211%.The methodfurther improves the electromagnetic flanging forming of small aluminum alloy tube fittings,and it has a certain significance for expanding the application of electromagnetic forming technology in aluminum alloy tube flanging.