超声振动系统f_s和Q_m的实验测定及对比研究

Experimental Mensuration and Contrastive Study of f_s and Q_m of the Ultrasonic Vibration System

以整个超声振动系统为研究对象,根据力电类比原理,利用计算机辅助测量导纳圆。基于导纳圆求得不同工况下振动系统的谐振频率fs和机械品质因数Qm。对比研究其变化规律并对其变化原因进行定性分析。研究表明,fs、Qm随工具杆工作深度的增加而普遍降低;负载温度越高,fs、Qm下降越明显;负载粘度增大,fs、Qm均有不同程度的降低;负载横截面积增大,fs略有提高,而对Qm的影响相对较小。在此基础上,同时考虑生产条件及加工要求,确定振动系统与超声波发生器的最佳电端匹配,对铝合金超声铸造具有一定的参考价值。

The whole ultrasonic vibration system is taken as a researchful object, and the admittance circle, aided by computer, is measured according to the theory of force-electricity analogy. Based on the admittance circle, the syntony frequency fs and mechanical quality factor Qm of the vibration system in different load cases are acquired. Their variational rules are eontrastively studied and the qualitative analysis of variational reasons for that is made. The study shows that fs and Qm generally decrease with the increase of working depth of the tool rod; the higher the load temperature is, the more obviously they decrease; with load viscosity increased, both fs and Qm decrease in different extents; and with its cross section area increased, fs has a little increase but Qm has been affected relatively lesser. On this basis, meanwhile, with the conditions of production and requirements of process consid- ered, the optimum electrical matching of the ultrasonic vibration system and ultrasonic generator is confirmed, which has some referenced worthiness to aluminum alloy casting treated by ultrasonic.