塑料超声波焊接负载阻抗模型及实时检测

On-line Measurement of Load Impedance in Ultrasonic Plastic Welding

从声学理论出发,分别对塑料超声波焊接声学系统各部分进行建模,并根据边界振速连续原则,建立了反映声学系统输入端电参数与输出端机械量之间关系的等效四端网络模型。为实现焊接过程声学系统负载阻抗的测量,本文还研制了超声波电参数在线检测系统,并在不同焊接工艺下对聚苯乙烯标准焊接试件进行了在焊过程负载阻抗检测。结果表明焊接过程声阻抗的变化与工件在焊接过程中焊接状态的变化存在着紧密的联系,这为焊接过程质量监测及实现焊接过程实时质量控制奠定了基础。

Based on acoustic theory,the equivalent network model of each part of the acoustic system in ultrasonic welding is set up,and then the four ports network model of the whole acoustic system is established according to the boundary vibration continuity principle in this paper,which can relate the input electric parameters of the acoustic system with the output mechanical parameters.An on-line ultrasonic electric measurement system is also designed in order to realize the measurement of the acoustic system load impedance during the uotrasonic plastic welding.Welding experiments are carried out with PS standard specimen under the different weldig conditions,and the results show that the acoustic load impedance can effectively reflect the welding state during the welding process,which puovides the foundations for monitoring the whole welding process and realizing the real-time quality control in ultrasonic plastic welding.