High Frequency Character of Piezoelectric Pump Valve

摘要

In order to improve the performance of piezoelectric pump, research its check valve, find the interpretation of the incomplete closure of piezoelectric pump check valve in high frequency, analysis the characteristic of the pump in these conditions; give the judgment basis and theoretical demonstration of the existence for the phenomenon. Frequency response of the check valve in water is obtained from its dynamic model. Sufficient condition for the check valve incomplete closure was obtained which is amplitude amplification less than 0.25. Amplitude amplification factor in different frequency was calculated. The results showed that check valve can close completely operating at 80Hz, the incomplete closure phenomenon was observed at 140Hz. With further increasing of the frequency, amplitude amplification factor decreases, the phenomenon is more obvious under the condition of low amplitude amplification factor, the minimum clearance between the check valve and valve seat more than 30μm at 160Hz. The theoretical analysis results are verified, that the critical frequency can be used as the yardstick for working state of check valve in piezoelectric pump.