Study On The Key Technologies Of Rotary Ultrasonic Maching Based On Accessoring Of The Machine Tool

Engineering ceramics are widely used in various areas such as aerospace, defense, electronics, automotive, bioengineering and other fields, However the ceramic materials is difficult to process because of their high hardness, brittleness and other characteristics. As a precision and efficient processing of engineering ceramics, rotary ultrasonic machining has attracted a lot of attention from international researcher. It is a key technical issue that the application of rotary ultrasonic maching is popularised by making the rotary ultrasonic machining head and load matching system accessories.The energy transfer efficiency and transfer capacity are small in conventional brushless rotary ultrasonic devices. There are software mode and hardware mode in existing accessory load matching system. The normal operation and maintenance are complex and the cost is high in software mode. Responding to the change rotary ultrasonic processing load is not sensitive enough and there are othere shortcomings in hardware mode.To solve the above problem, a accessory load matching system and a accessory rotary ultrasonic device are researched and designed. A new brushless energy transferring device based on the principle of electromagnetic induction is developed. On-line monitoring tool wear is studied during rotary ultrasonic machining. The studies in this paper include the following aspects:1) A load matching system of accessoring machine tool is developed, whose core component is an air bearing workbench. The air bearing workbench adops an aerostatic guide. Based on gas lubrication theory, the bearing capacity and stiffness of the aerostatic guide are analyzed and measured by finite element method and experimental method. The monitoring force system and controlling force system of the load matching system are also designed.2) Based on the principle of electromagnetic induction, a non-contact power transmission collector used in rotary ultrasonic machining is developed. The working performances of four collectors are analyzed by finite element method and are verified by experiments. The circuit compensation method of the primary and secondary circuits is discussed. When the secondary circuit is transducer, the circuit compesnsation is proposed. The circuit compesnsations are analyzed by finite element analysis and are verified by experiments.3) A rotary ultrasonic device is designed, whose important component is a cylindrical induction power transmission collector. Dynamics of the horn is analyzed by finite element analysis and structure of the horn is designed.4) A device of rotary ultrasonic drilling of SiC is established for on-line monitoring the process by piezoelectric sensor, vibration sensor and acoustic emission sensor. Tool wear and tool wear mechanism are analyzed by observing the surface morphology. The signal characteristics of tool wear is extracted by processing signals.5) The load matching system can be employed to protect the workpiece from damage during rotary ultrasonic machining, which is confirmed by observing the machined workpiece surface and analyzing the signals.