抄録
The research finds that it is wrong that the increase of the frequency results in the decrease of the amplitude of piezo vibrator is the main cause for the phenomena that at the time of increasing the frequency but decrease the flow output. And the experiment has testified that the existing theory is incorrect; then put forward that valve lag is the main cause for the phenomena that at the time of increasing the frequency, and decrease the flow capacity. Finally, a new type valve which in "E" shape is introduced accord with the theory of the valve lag.
