Design of a half-wave vibration system for ultrasonic drilling

In order to prevent exit and entry of carbon-fiber composites from splitting, internal material of carbon-fiber composites from delamination and brittle fracture, and cutters from wearing rapidly during drilling, a portable revolving ultrasonic drilling machine was designed. It can be used to drilling giant components made of carbon-fiber composites at different angles and in different directions. Based on one-dimensional vibration theory, a half-wave vibration system which has advantages such as compact size (130 mm long), light weight (1.6 kg) and small moment of inertia was presented. Using cutters with different diameter, length and material for different machining requirement would lead to the shift of resonance frequency of the vibration system, so a method of impedance matching between cutter and vibration system was given according to the impedance matching law. As a result, the vibration system has good resonance after cutters are changed.