力负载对超声切割声学系统谐振频率及谐振阻抗的影响  

Influenceof load on resonance frequency and resonance impedance of an ultrasonic cutting acoustic system

作　　者：纪华伟[1] 虞文泽[1] 胡小平[1] 

机构地区：[1]杭州电子科技大学机械工程学院,杭州310018

出　　处：《振动与冲击》2016年第23期136-141,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金(51475130);国防科工局重大专项(A3920133001);浙江省重中之重学科开放基金

摘　　要：针对在蜂窝复合材料超声波切割加工中,超声切割系统在受力之后会出现系统失谐,振幅不足甚至停振的现象,对声学系统受力之后的阻抗值以及谐振频率进行研究。利用四端网络法,通过分析变幅杆、压电陶瓷以及端盖等组成声学系统各部分输入输出特性,提出了声学系统的整体设计方程,得出了声学系统的阻抗值和频率方程以及负载﹑电流与振幅的关系式,并对超声切割系统的受力模型进行分析;通过对超声切割声学系统施加单向力,分析受力之后的声学系统阻抗值和谐振频率,得出声学系统受力对系统阻抗值和谐振频率的影响规律。实验结果表明:增加三个方向力之后,系统的阻抗值和谐振频率都会上升;随着力负载的增加,Y、Z方向施加力负载时的系统阻抗值比X方向施加力负载时增加得更快,而在系统谐振频率方面,X、Z方向施加力负载时谐振频率的增量比Y方向施加力负载时更大,在实际应用中应减小敏感方向的力;研究成果可为实际加工蜂窝复合材料提供理论指导。An ultrasonic cutting system may have out of harmony,insufficient amplitude,even non-resonance when bearing a load,these lead to serious effects on machining process and machining quality of a workpiece.Here,the impedance and the resonance frequency of a loaded acoustic system were studied.By using the 4-terminal network method,the input /output characteristics of ultrasonic horn,piezoelectric ceramics and end cover were studied,the whole body design equation of an acoustic system was presented,and the impedance,frequency equation and the relationships among load,current and amplitude of the acoustic system were obtained.In order to get influence laws of load on the impedance and resonant frequency of the system,a digital push-pull meter was used to exert a load in a single direction on the acoustic system,the relationships among impedance,resonant frequency and load were tested.The test results showed that the impedance of the system increases after loads are exerted in three directions;with increase in load,the impedance of the ultrasonic cutting system when loads are exerted in Y and Z directions increases faster than that does when load is exerted in X direction;the increments of resonant frequency of the ultrasonic cutting system when loads exerted in X and Z directions are much more than that be when load is exerted in Y direction;the load in the sensitive direction should be reduced in practical application.The results provided a theoretical guidance for the actual processings.

关 键 词：超声切割系统 力负载 受力模型 阻抗值 谐振频率 

分 类 号：TG663[金属学及工艺—金属切削加工及机床]