Study On The Key Technologies Of Rotary Ultrasonic Machining Device Based On Local Induction Contactless Energy Transfer

Hard and brittle non-metallic materials and composites are widely used in the aerospace,defense,electronics,automotive,bio-engineering and so on.As a precision and efficient processing method of hard and brittle materials and composites,rotary ultrasonic machining has been widely concerned by research staff from all over the world.Compared to the traditional non-rotating ultrasonic machining,the rotary motion of rotary ultrasonic machining makes ultrasonic energy transfer more complicated and difficult,which greatly limits the application of the rotary ultrasonic machining techniques.In order to satisfy the rapid developments of high efficiency and high-precision machining of advanced materials,the development of high speed,high efficiency,high power rotary ultrasonic machining equipment has become a hot topic at present.Contactless energy transfer(CET)based on electromagnetic induction can be replaced with the traditional slip ring brushes for providing electrical power to the ultrasonic transducer.This contactless energy transfer(CET)is security,stability,and no restrictions of speed.However,due to the air gap existing in primary and secondary side,rotary transformer has larger leakage inductance,poorer coupling capacity compared to the tightly coupled transformer.Its transmission efficiency and transmission power is limited.Secondly,amplitude decay caused by the change cutting force and temperature of ultrasonic machining affects the machining results.To solve the above problems,following aspects were studied in this paper:a.The design of the rotary ultrasonic machining spindle device,the new structure of rotary ultrasonic machining can achieve high power,high speed,and simplify the operation of tool replacement,reduces the installation precision,which can realize the automatic tool change of machining center,besides,the feasibility of two kinds of structure are verified by experiments;b.Considering the real electrical properties of ultrasound vibrator,circuit compensation topology,mathematical model to characterize the transmission efficiency and power transfer capability,calculation of circuit compensation components to achieve maximum transmission efficiency were established.The effect rules and mechanisms of compensation component values and equivalent series resistance(ESR)on the energy transfer properties were theoretically and experimentally studied;c.Based on Ansoft and Multisim simulation software,the non contact energy transfer circuit is simulated,which greatly simplifies the calculation process of the non contact energy transfer circuit;d.The influence of load force and temperature on the performance of the rotating ultrasonic machining was discussed.The optimum compensation method was determined by comparison under different cutting force and temperature;e.The design of electric control cabinet of rotary ultrasonic machining device realizes automatic matching and automatic control.