Design And Analysis Of Non-resonant Ultrasonic Machining Flexible Mechanism

Devices with micro-nanoscale structure are widely used in aerospace,biomedical,optics,semiconductor and other industries.The research on non-resonant ultrasonic elliptical vibration machining aids for micro-nano structure processing has certain theoretical value and practical significance for improving the manufacturing technology of micro-nano processing.In this paper,based on the principle of elliptical vibration machining,the design theory of non-resonant ultrasonic elliptical vibration machining AIDS is systematically studied,and the physical prototype is manufactured,and the positioning accuracy of vibration platform and micropositioning platform is verified by performance test.The main work of this paper is as follows:(1)A non-resonant three-dimensional elliptical vibration machining aided platform is designed with resonance frequency as constraints,which realizes the adjustability of frequency,amplitude and equal vibration parameters.The static and dynamic models of the vibration platform are established and the dimension parameters of the flexible mechanism are optimized accordingly.Based on the working characteristics of the piezoelectric actuator,the mapping relationship between the actuator elongation and the output displacement of the flexible mechanism is established.The static and dynamic characteristics of the vibration platform are analyzed based on Ansys Workbench software.(2)A two-degree-of-freedom micro-positioning platform is designed to solve the problems of limited multiplier of single-stage amplifier and large coupling error of micro-positioning platform.A two-stage lever amplifier and a Scott-Russell mechanism are designed for the platform,which form a three-stage displacement amplifier in series and enlarge the working stroke of the platform.The decoupling mechanism is composed of parallel axle flexible hinge and double compound parallel moving pair,which eliminates the motion coupling error.Based on Lagrange’s theorem,the stiffness relation of the micro-positioning platform is derived,its dynamic model is established and the natural frequency of the system is obtained.The maximum working stroke,amplification factor and coupling error of the micro-positioning platform are analyzed by finite element software simulation.(3)Vibration platforms and micro-positioning platforms are manufactured and assembled into non-resonant ultrasonic machining flexible mechanisms.The natural frequency and vibration track of the vibration platform are tested to verify the positioning accuracy of the vibration platform.Natural frequency,maximum displacement,coupling error,step response,motion resolution and signal tracking error of the micro-positioning platform are tested to verify the positioning accuracy of the micro-positioning platform.