超声辅助电火花加工装置的研制及其振动特性研究

Development of Ultrasonic-assisted EDM Device and Investigation on Its Vibration Properties

针对电火花加工过程中排屑不畅及容易拉弧、短路的问题,提出了基于工具电极振动的超声辅助电火花加工方案。设计了超声辅助电火花加工装置的结构形式,通过APDL建立有限元模型进行模态分析,确定出使用夹心式压电换能器的轴向纵振模态,着重探究了干模态和湿模态对谐振频率的影响;随后进行谐响应分析,研究激励电压频率对振幅输出特性的影响规律;最后进行了装置的制造及装配,测试了其阻抗特性及振型,并最终标定出其电压-振幅输出曲线。基于平台开展了电火花试加工实验,验证了超声辅助电火花加工方案的可行性和有效性。

In order to improve the debris evacuating function while avoid the occurring of arcing and short circuit during the EDM process,an ultrasonic-assisted EDM device was proposed based on the vibration of tool electrode. Firstly,a FEM model based on APDL was established to determine the geometry of the ultrasonic-assisted EDM device. The axial longitudinal vibration mode was confirmed for the sandwich piezoelectric transducer by the model analysis,and the effect of the dry model and wet model on the resonant frequency of the transducer were analyzed. Moreover,the harmonic response analysis was employed to investigate the effect of the excitation voltage frequency on the output of vibration amplitude. Finally,the ultrasonic-assisted EDM device was manufactured and assembled,and the impedance characteristics and vibration mode shape were measured,while the voltage-amplitude output curve was also calibrated. The experiment result based on the device verified the availability and efficiency of the ultrasonic-assisted EDM method.