Hongbing Wang

Research on Performance Parameters of the Piezoelectric Vibrator in Ultrasonic EDM System

Ultrasonic EDM which is a novel machining approach for hard materials is developed quickly. In ultrasonic EDM processing the piezoelectric vibrator has a very important influence on the quality of the machining. The purpose of the paper is to study the performance parameters such as the first longitudinal modal frequency, node plane and vibration amplitude of the vibrator . Through FEM (finite element method ) simulation method the relation between structure parameters and the performance parameters are obtained. The results of the paper are very effective to design a vibrator for ultrasonic EDM.

Theoretical Analysis and FEM Simulation of Piezoelectric Vibrator Used in Ultrasonic EDM System

The dynamic performance of the piezoelectric vibrator used in ultrasonic EDM machine in natural frequencies has a great effect on machining precision. Firstly, Through theoretical analysis the dynamic characteristics of the piezoelectric vibrator is obtained. Then the three-dimensional model of the piezoelectric vibrator is constructed by using PRO/E software, and model analysis is carried by using FEM software. Through theoretical analysis and FEM simulation, the appropriate working frequency and mode of the piezoelectric vibrator was found, and the piezoelectric vibrator was fabricated. Experimented results show that the model analysis of frequency is accord with that of FEM.

Effect of Structure Parameters on Dynamic Characteristics of Piezoelectric Vibrator in Ultrasonic EDM Processing

A piezoelectric vibrator in ultrasonic EDM processing is designed and fabricated. The structure parameters of the vibrator have a very significant impact on the dynamic characteristics. The effect of different structural parameters on dynamic characteristics of the vibrator is analyzed by using Finite Element Method(FEM), and the modal frequency and vibration amplitude sensitivities of the vibrator to the structural parameters are investigated by modal and harmonic analysis.. According the results of the sensitivities analysis, the structural parameters which have an important impact on the working modal frequency and the vibration amplitude are achieved. The vibrator is designed and made based on the above theoretical analysis. The dynamic characteristics of the piezoelectric vibrator are tested. In the case of exciting voltage of 100V (peak-peak value), the first-order longitudinal vibration frequency (working frequency) of the vibrator is 27.36 kHz, vibration amplitude is about9.8μm, which is in compliance with the theoretically analytical results.

Study on V-Shaped Linear Ultrasonic Motor and its Experiments

A V-shaped linear ultrasonic motor with a stator and a slider has been developed. The stator consists of two orthogonal Langevin actuators which is joined together in their ends. The Langevin actuators are symmetrical and have same first order longitudinal mode. A linear motion of the slider is generated by friction between the stator and the slider when the two first order longitudinal modes are combined. In this paper, structural dynamic design on the stator is completed with Finite Element Method(FEM). The prototype motor is manufactured based on the design results. The operation modes of the stator and the output performances of the motor are tested. The diameter and length of the Langevin actuator are 20mm and 58mm, respectively. The mass of the stator is 290g. The first order longitudinal frequency of the Langevin actuator is 27.47 kHz (FEM simulating result) and 27.36 kHz (expermental result), respectively. The maximum driving force of the motor approaches 40N. The maximum velocity of the motor is about 100 mm/s. So the stator’s operation modes are consistent with the design results, and the motor output properties have characteristics of slower velocity and stronger force.