Development of an ultrasonic complex vibration source that produces an elliptical vibration locus

: Conventional ultrasonic welding uses linear vibrations, but welding using an elliptical locus improves welding strength. Therefore, we developed a vibration source that generates an elliptical locus using a single longitudinal vibration transducer. Although vibration sources with an elliptical locus have been reported previously, they were designed using the equivalent transmission line method. In this paper, we used the finite element method to elliptical vibration source design, and we fabricated a vibration source and measured its characteristics. Bringing the resonance frequencies of the longitudinal and torsional vibration closer together allowed vibration with an elliptical locus to be obtained at a single frequency.