模式转换型超声塑焊振动系统的设计

Design of ultrasonic vibration system with vibration mode-conversion for ultrasonic plastics welding

基于弯曲振动理论和耦合振动理论,设计了一种新型大尺寸筒形超声塑焊振动系统。该振动系统由纵向振动换能器及变幅杆、弯曲振动金属圆盘和耦合振动圆筒四部分组成。换能器和变幅杆的纵向振动驱动圆盘的二次弯曲模式振动,圆盘的二次弯曲模式振动激励圆筒的纵向模式振动,实现了工具头在较高频率下谐振。实验结果表明,振动系统的测试频率与计算频率比较符合,在大信号下测试的纵-弯-纵振动模式转换效果很好。研究结果为高频大尺寸超声焊接系统的设计提供了思路。

Based on the theory of flexural vibration and coupled vibration,a new hollow cylinder type ultrasonic vibration system with large diameter for ultrasonic plastics welding is designed.This vibration system consists of a transducer,an ultrasonic horn,a plane and a hollow cylinder.The transducer and horn vibrated in longitudinal mode are used to drive a plane vibrated in its second flexural mode.At the same time,while the plane vibrated in its second flexural mode,it is used to drive a hollow cylinder in longitudinal mode vibration.By taking use of the transition between the different vibration mode,the hollow cylinder having large diameter vibrated as a piston in its end surface in higher frequency mode.The experimental results show that the measured resonance frequencies of the system are in good agreement with the computed ones and the system vibrated very well in its longitudinal- flexural-longitudinal vibration mode.The result from this paper will provide assumption for the design of ultrasonic welding system having large diameter when the higher resonance frequency is needed.