Study On Micro Ultrasonic Welding Vibrator And Its Welding Characteristics

As a new type of connection technology,ultrasonic welding has been widely used in many fields.In order to simplify the complex structure of the traditional ultrasonic welding device and expand the frequency domain of the welding vibrator,this thesis proposed and developed a new type of micro ultrasonic welding vibrator which is different from the Langevin vibrator.Based on the welding vibrator,a double vibrator welding method is proposed that can improve the welding efficiency.Based on the theory of sound propagation and sound transmission,this thesis designs a megasonic welding vibrator with a matching layer structure.The welding vibrator is subjected to stress analysis,modal analysis and harmonic response analysis using finite element software.The size of the welding vibrator is reasonably miniaturized by finite element analysis.Based on the optimal design parameters,a micro ultrasonic welding vibrator was processed.The dynamic characteristics of resonance frequency and overall amplitude distribution of the welding vibrator are tested,and the tested results are in good agreement with the simulation analysis.The multi-physics coupling method is used to numerically simulate the temperature field in plastic welding,and the temperature rise process of the contact surface of the weldment and the influence of the material and geometry of the weldment on the temperature field are simulated.The thesis uses the developed welding vibrator to conduct a micro-ultrasonic welding experiment and explores the main factors that affect the welding quality.In order to improve the welding efficiency,a double-vibrator "butt welding" method is proposed and experimented.Compared with single-vibrator welding,the double-vibrator butt welding has more advantages.This method provides a feasible scheme for the application of micro ultrasonic welding with high efficiency and high quality.