Piezoelectric valve, driving method of the piezoelectric valve, and optical granular material sorting machine including a blowing means using the piezoelectric valve

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric valve showing superior responsiveness at the time of opening of the valve and capable of stabilizing gas supply at an early time.SOLUTION: A piezoelectric valve 10 is a piezoelectric valve having a gas pressure chamber 111 for receiving compressed gas supplied from an external part and a gas discharging passage 112 for discharging the compressed gas from the gas pressure chamber. There are provided a valve body 12 arranged at the gas pressure chamber to open or close the gas discharging passage; a piezoelectric element 13 for generating a driving force required for operating the valve body as a displacement value; a displacement expansion mechanism 14 for expanding a displacement of the piezoelectric element to act against the valve body; and driving means 15 having a signal generating part for generating a signal including a first pre-pulse, a second pre-pulse and a main pulse so as to apply a driving voltage to the piezoelectric element while applying the signal as an input signal for the driving circuit, extending the piezoelectric element and driving the valve body to open it.SELECTED DRAWING: Figure 1