Frequency characteristics analysis of ultrasonic blanking die using FEM --optimal design for a stepped solid horn

摘要

In this paper, we describe a design method for stepped solid horns using the FEM (Finite Element Method) and the experimental evaluation of an ultrasonic blanking die. A simulation method for an ultrasonic vibration system by FEM is proposed to determine the optimal size of a stepped solid horn. In this simulation method, the forced vibration and the damping are considered, and the calculation model is not only applicable to a horn but also to an ultrasonic vibration system comprising a cone, a tool horn, a flange and a vibrator. An ultrasonic tie-bar cutting die has been developed based on the FEM optimal design. The effects of ultrasonic vibration on blanking were experimentally investigated using this die. By comparing the FEM simulation results with experimental results on the amplitude of the tool horn and the frequency characteristics of the ultrasonic vibration system, it is clarified that the proposed simulation method is valid for the design of an ultrasonic vibration system. It is also found that the shearing force is decreased and the clearance is increased by ultrasonic vibration.