Abstract: The method of pulse width modulation in electrical science is introduced to flow rate control in pneumatic system as a method for saving energy. It is proved that the method of intermittent had a better performance and consumed less energy in blowing away dust. A self-oscillated mechanical structure for generating intermittent air flow is put forward. The structure is valve like and based on spring vibrator. The force generated by compressed air on the surface of the valve core overcomes the friction, in order that the valve core driven by a spring force vibrates periodically. The mechanism of generation of the stable vibration is found. The amplitude is influenced by the standard time of charging and discharging. If the time is reduced, the amplitude will decrease even the vibration can not generated stably. The machine gets character of generating different frequency and duty ratio of intermittent air flow by designing the elastic coefficient of spring and position of the port of which compressed air flows out. We studied the principal of self-oscillation by simulating this machine. The simulation results are verified the experiment results. Finally, the mechanism of pressure loss is studied when the port is opening and opened wholly. With the experiment data, the efficiency of the machine is calculated and that is 9%.

Key words: Energy saving, Intermittent blowing, Pulse generator, Self-oscillation