基于电涡流阻尼器的数控加工振动抑制

弱刚性零件在数控加工中极易发生变形、让刀等现象，对加工质量及效率构成严重影响。基于电涡流阻尼器利用导体在恒定磁场中运动或者利用时变电磁场在导体上产生电涡流阻尼力，提出并设计适用于弱刚性结构件数控加工振动抑制的电涡流阻尼器结构；结合理论建模，提出四种设计方案并对其减振性能进行测试和比较。模态实验表明，四种阻尼器方案均能较好的对工件振动进行抑制，频响函数幅值最低下降55%；模态参数辨识表明，电涡流阻尼器可使系统阻尼增加70.73%，而对其余动力学参数的影响较小。切削实验表明，该电涡流阻尼器可增加工件临界稳定切深171%，减少切削加工振动信号58%以及降低表面粗糙度89.7%。

Vibration suppression of NC machining based on eddy current damper

Large deformation and cutter run-out are apt to occur when machining flexible structures, which quite restrict the machined surface quality and efficiency. Eddy current damper utilizes the motion of conductor in a uniform magnetic field or time-varying electromagnetic field to generate electric eddy current force. A setup is therefore proposed to suppress vibrations of flexible parts during machining process based on the force mentioned above. According to the theoretical model, four damping configurations are proposed, tested and compared. Modal tests show that the amplitude of frequency response function is reduced by 55% maximum. Furthermore, modal parameter identification shows that the dampers can increase the system damping by 70.73%, while other dynamic parameters are little affected. Cutting tests indicate that the eddy current damper can increase critical depth of cut by 171%, attenuate vibration amplitude by 58% and reduce surface roughness by 89.7%.