The Research Of A Rotary Ultrasonic Vibration System Design And Its Key Techniques

With the growing demand for the processing needs of hard brittle materials and composites, the new rotary ultrasonic machining method can be adapted to the requirement of modern production, but it has not formed perfect design theory and analysis system in domestic on the study of the key technique (the research of ultrasonic generator and ultrasonic vibration system) so far. The ultrasonic vibration system is the key and core of ultrasonic machining and the necessity and importance of the research is urgent.In this paper, the structural design of transducer,horn and tool bar are designed based on the utilization of longitudinal vibration theory, and an stepped transducer of half-wavelength as well as a vibration system with three different tool heads are designed. The complex ultrasonic vibration systems at each velocity and stress distribution was derived using four-pole network in order to analysis of the performance parameters. Through the modal analysis and resonant analysis of the designed ultrasonic transducer,horn and vibration system by ANSYS, we get the simulation results of various order of the vibration transducer, and obtain the resonant frequency with 20228Hz, the amplitude also reaches the demand of rotary ultrasonic machining above 10μm. The vibration system with three different tool bar can realize longitudinal vibration, the resonant frequency of 20.251kz,20.324kHz,20.438kHz and the frequency error range of 1.255%,1.62%,2.19%. With the decrease of the tool head's diameter, frequency error range increase, the design error less than 5%, in allowable error design range.It can completely satisfy with the need of engineering design.The experimental study and finite element ananlysis on the 3 designed vibration system have been done.Through milling and drilling process test on different materials:common glass,k9 Optical glass,ceramic alumina and zirconia.Experimental results have been shown that rotary ultrasonic can well machine glass, optical glass,ceramics and other hard brittle materials, along with the increase of feed and cutting depth,cutting efficiency increases, but cutting resistance is also increased.The higher the rotation cutting speed, the smaller the machining resistance.The machining experiment of Alumina ceramic without ultrasonic shows that the metal removal rate with ultrasonic is 5 times of that without ultrasonic machining.Processing alumina ceramic, with cutting depth and tool feed increase, the surface roughness value is also increased.The finer the size of diamond grits, the bigger the machining resistance, if the size of diamond grits is 100# and feed rate is 40mm/min,the machining resistance is 2.3kg. If the size of diamond grits is 120# and feed rate is 30mm/min,the machining resistances reaches a maximum of 4.5 kg,so the size of diamond grits directly influence the choice of the cutting parameters.The ultrasonic vibration system designed in this paper can process brittle materials well such as glass and ceramic, and have a high processing efficiency. It fully proves that rotary ultrasonic machining is an effective machining method for hard brittle material.