Development Of Ultrasonic Generator For Ultrasonic Assisted Grinding

Ultrasonic assisted grinding is the combination of ultrasonic vibration with traditional grind technology, which is valuable in the application of difficult-to-cut materials. Stable ultrasonic vibration is one of the key factors on guaranteeing ultrasound assisted grinding quality. The main function of ultrasonic generator is used to excite transducer and make the transducer reach resonant state. Output characteristic of ultrasonic generator determines the ultrasonic vibration state. Therefore ultrasonic generator is one of the key factors of deciding ultrasonic assisted grinding quality.This paper divided ultrasonic generator into main circuits and frequency tracking circuits. The main circuits included signal generation module, power amplifier module and transducer matching modules, which realized the vibration of the transducer. Frequency tracking circuit included signal sampling and signal processing.The paper main studying contents and the conclusions are as follows:(1) The basic principle of DDS technology was introduced. This paper designed signal producing module based on the DDS chip AD9580, and analyzed the programming methods of AD9850chip.(2) Topology structure of power amplifier circuit and power components were analyzed choice. The paper selected series voltage switching amplifier as power amplifier circuit topology structure and IGBT as power components, and designed power amplifier drive circuit based on the IR2110.(3) The paper studied the theory of piezoelectric transducers and did an impedance analyzing test, and also designed a matching inductance.(4) The following conclusions could be obtained by studying the influence of ultrasonic assisted grinding on resonant frequency:â‘ the ultrasonic assisted grinding parameters will affect the change of resonant frequency and the bigger of load the higher of resonant frequency.â‘¡the resonance frequency offset is within200Hz by the experimental parameters used in the paper;â‘¢fast frequency tracking must be introduced in order to guarantee the stability during the process of ultrasonic assisted grinding.(5) Frequency tracking circuit based on phase was designed in the paper, which included signal sampling, phase difference obtaining and phase position judgment three parts. And the program of frequency tracking was also analyzed and designed in the paper. An ultrasonic generator was made in the paper. Its output performance and frequency tracking performance were tested. The test results showed that the power output waveform was nice and frequency tracking characteristics was effective and satisfied the need of ultrasonic.