Research On Small Ultrasonic Feeder Based On Piezoelectric Effect

In recent years, piezoelectric actuators and their theory is being developed rapidly in China, which is especially widely used in ultrasonic piezoelectric conveying. Taking continuous work of the project (No. 50675094) of National Natural Science Foundation of China as the research background, a new structure of small ultrasonic feeder is proposed on the basis of the extant ultrasonic vibratory feeding device, and then this feeding prototype is produced.Based on the conventional structure of feeder and the theory of elastic vibration, the feeding vibrator of which the interior part has trapezoidal teeth is proposed. The modal of vibrator is analyzed using the FEM(Finite Element Method), followed by the bonding method of piezoelectric ceramic and then the geometrical dimensions of the vibrator are optimized. Based on the result of dynamic design and analysis, feasibility of machining and precision, the proposed small ultrasonic feeder is produced, and its diameter of discharging side is 16mm. The third in-plane bending mode of vibration is selected for the vibrator.With the laser doppler vibrometer, the bending vibration mode and resonant frequencies are tested, which is relying on mirror reflection principle. Working frequency of the vibrator is 22261Hz. The results show, this vibration feeder can produce uniform traveling wave. The whole feeding device is assembled, and the feeding performance of ultrasonic vibratory feeding device is tested. The test shows when a certain voltage excition is applied to the vibrator, the feeding can be controlled.