JP5265999B2 - Electrostatic atomizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily ensure a high voltage required for electrostatic atomization even if there is dispersion by a solid with its natural frequency in a high voltage generating circuit. <P>SOLUTION: An electrostatic atomizing device includes an atomizing electrode 1, a water feed means 2 for feeding water to the atomizing electrode 1 and a high voltage generating circuit 3 for applying high voltage to the atomizing electrode 1. The water fed to the atomizing electrode 1 is electrostatically atomized in the high electric field generated by applying the high voltage. A controlling means 4 is installed which controls the output of the frequency to the high voltage generating circuit 3 corresponding to the natural frequency of the high voltage generating circuit 3. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a technique for generating charged fine particle water by utilizing an electrostatic atomization phenomenon.

  Conventionally, an atomizing electrode, water supply means for supplying water to the atomizing electrode, and a high voltage generating circuit for applying a high voltage to the atomizing electrode, the water supplied to the atomizing electrode is An electrostatic atomizer that performs electrostatic atomization with a high electric field generated by application of a voltage is known.

  In the conventional electrostatic atomizer, PWM control is performed with the pulse signal output from the control means in order to generate a high voltage, and the frequency of the high voltage control signal output from the control means to the high voltage generation circuit is fixed. Then, by changing the duty ratio, the high voltage output from the high voltage generation circuit reaches the target value.

  However, the high voltage generation circuit has frequency characteristics, and a large amplification factor can be obtained at a specific natural frequency. However, the amplification factor decreases as the frequency deviates from the natural frequency. That is, when the input voltage is fixed, a large high voltage is obtained at a specific natural frequency, but the high voltage decreases as the frequency deviates from this natural frequency.

  In order to perform electrostatic atomization, it is necessary to apply a predetermined high voltage to the atomization electrode. In the conventional method in which the frequency of the high-voltage control signal is fixed, the high-voltage generation circuit having a large variation in the natural frequency has a duty cycle. Even if the ratio is maximized, the high voltage necessary for electrostatic atomization may not be ensured.

On the other hand, the natural frequency of the high voltage generation circuit varies greatly among individuals , and it is very difficult to suppress this variation at a low cost in mass production.

The present invention has been invented in view of the above-described conventional problems, and easily secures a high voltage necessary for electrostatic atomization even if there is a variation among individuals in the natural frequency of the high voltage generation circuit. It is an object of the present invention to provide an electrostatic atomizer capable of performing the above.

The electrostatic atomizer according to the present invention includes an atomization electrode 1, water supply means 2 for supplying water to the atomization electrode 1, and a high voltage generation circuit 3 for applying a high voltage to the atomization electrode 1. The water supplied to the atomizing electrode 1 is electrostatically atomized with a high electric field generated by the application of the high voltage. The features of the present invention, the control means 4 for controlling the frequency output of the high voltage control signal to the pre-Symbol high-voltage generating circuit 3 is provided, the control means 4, and the maximum duty ratio of the high voltage control signal Sometimes at least the frequency at which a high voltage required for electrostatic atomization is secured as the high voltage output from the high voltage generation circuit 3 is controlled by the high voltage control from the control means 4 at the time of initial setting before use. The frequency output of the signal is automatically set, and then the duty ratio is changed so that the high voltage output from the high voltage generation circuit 3 reaches the high voltage necessary for electrostatic atomization. There is to do.

With this configuration, even if the natural frequency of the high voltage generation circuit 3 varies depending on the individual, the frequency to the high voltage generation circuit 3 is controlled by the control means 4 according to the specific frequency of the high voltage generation circuit 3. The output can be automatically set to a high voltage necessary for electrostatic atomization.

The control means 4 preferably controls the frequency output of the high voltage control signal from the control means 4 so as to have a specific peak frequency of the high voltage generation circuit 3.

Thus, by controlling the frequency output of the high voltage control signal from the control means 4 so as to have a specific peak frequency of the high voltage generation circuit 3, an optimum high voltage necessary for electrostatic atomization can be obtained. Can be secured.

  Moreover, it is preferable that the said control means 4 controls a frequency output based on the high voltage output from the high voltage generation circuit 3 when changing a frequency output.

  With such a configuration, the control means 4 can easily detect the natural frequency of the high voltage generation circuit 3 while observing the change in the high voltage output from the high voltage generation circuit 3 by changing the frequency output. The frequency output of the high voltage control signal from can be automatically set.

The present invention, as described above, since the high voltage generating circuit is provided with control means for controlling the frequency output to the high voltage generating circuit in accordance with the specific frequency, by the individual to the natural frequency of the high voltage generating circuit even if there are variations, the control means, in response to variations due to the natural frequency of the individual high voltage generator circuit, easily ensure a high voltage required for electrostatic atomization by setting the frequency output of the high voltage control signal can do.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

  FIG. 1 is a control block diagram of the electrostatic atomizer 5 of the present invention. The electrostatic atomizer 5 includes an atomizing electrode 1, a water supply means 2 for supplying water to the atomizing electrode 1, and an atomizing electrode 1 for electrostatically atomizing water supplied to the atomizing electrode 1. And a high voltage generation circuit 3 for applying a high voltage to the water supplied to the water. In FIG. 1, 4 is a control means comprising a microcomputer, 9 is a discharge current detection circuit, 10 is a high voltage detection circuit, 3 is a high voltage generation circuit, 5a is an atomizing block, and 7 is a Peltier power supply circuit.

  In the embodiment shown in the accompanying drawings, an example is shown in which the water supply means 2 is constituted by a cooling means for supplying water to the atomizing electrode 1 by generating moisture in the air as condensed water. .

  In the embodiment shown in FIG. 1, the cooling means is constituted by the Peltier unit 6, and water is supplied to the atomizing electrode 1 by generating moisture by cooling the moisture in the air by the cooling means. ing.

  The Peltier unit 6 has a pair of Peltier circuit boards in which a circuit is formed on one side of an insulating plate made of alumina or aluminum nitride having high thermal conductivity, facing each other so that the circuits face each other, and arranged in multiple rows. A BiTe-based thermoelectric element is sandwiched between both Peltier circuit boards, and adjacent thermoelectric elements are electrically connected by circuits on both sides, and the Peltier power supply circuit 7 formed via a Peltier input lead wire is transferred to the thermoelectric element. Is configured such that heat is transferred from one Peltier circuit board side to the other Peltier circuit board side. Further, a cooling part is connected to the outside of the Peltier circuit board on one side, and a heat radiating part is connected to the outside of the Peltier circuit board on the other side. Can be mentioned. The rear end of the atomizing electrode 1 is connected to the cooling part of the Peltier unit 6.

In the embodiment shown in the accompanying drawings paired counter electrodes 8 so as to face the atomizing electrode 1 are arranged. And in embodiment shown to an accompanying drawing, the atomization block 5a is comprised by the Peltier unit 6, the atomization electrode 1, and the counter electrode 8. FIG.

  In the electrostatic atomizer 5 having the above-described configuration, the cooling unit is cooled by energizing the Peltier unit 6, the atomizing electrode 1 is cooled by cooling the cooling unit, and moisture in the air is condensed. Water (condensation water) is supplied to the atomizing electrode 1.

  When a high voltage is applied from the high voltage generation circuit 3 between the atomizing electrode 1 and the counter electrode 8 in a state where water is supplied to the atomizing electrode 1 in this way, the atomization electrode 1 and the counter electrode 8 The Coulomb force acts between the water supplied to the tip of the atomizing electrode 1 and the counter electrode 8 due to the high voltage applied between them, and the water level rises locally in a cone shape (tailor cone). It is formed. When the tailor cone is formed in this way, the electric charge concentrates on the tip of the tailor cone and the electric field strength in this portion increases, thereby increasing the Coulomb force generated in this portion and further growing the tailor cone. . When the tailor cone grows like this and the charge concentrates on the tip of the tailor cone and the density of the charge becomes high, the water at the tip of the tailor cone has a large energy (repulsive force of the charge that has become dense). In response to this, a large amount of nanometer-sized charged fine particle water charged negatively or positively is generated by repeating splitting and scattering (Rayleigh splitting) beyond the surface tension. The generated charged fine particle water is discharged to the outside of the electrostatic atomizer 5.

  Then, based on the cooling control signal output from the control means 4, a cooling voltage is output from the Peltier power supply circuit 7 to the Peltier unit 6, and moisture in the air is generated as condensed water by the cooling action of the Peltier unit 6. Thus, dew condensation water is supplied to the tip of the atomizing electrode 1.

  When a high voltage control signal is output from the control means 4 in this state, a high voltage is output from the high voltage generation circuit 3 based on the high voltage control signal, and a high voltage is applied to the atomizing electrode 1 as described above. Electrostatic atomization of water at the tip of the atomizing electrode 1 is performed, and nanometer-sized charged fine particle water is generated.

  Here, the discharge current detection circuit 9 detects the current during discharge, the discharge current detection circuit 9 outputs a discharge current signal to the control means 4, and the control means 4 generates a high voltage based on the discharge current signal. The circuit 3 and the Peltier power supply circuit 7 are PWM-controlled.

In the electrostatic atomization apparatus 5 as described above, the present invention can secure a high voltage necessary for electrostatic atomization by the control means 4 composed of a microcomputer according to the specific frequency of the high voltage generation circuit 3. 3 is characterized in that the frequency output to the high voltage generation circuit 3 is controlled.

That is, since the natural frequency of the high voltage generating circuit 3 varies depending on the individual , the frequency output of the high voltage control signal from the control means 4 to the high voltage generating circuit 3 corresponding to the natural frequency of the high voltage generating circuit 3 is performed. The frequency output is set so that the high voltage necessary for electrostatic atomization can be secured by control.

  The setting of the frequency output is automatically performed by the control means 4 when the electrostatic atomizer 5 is initially set.

FIG. 2 shows a control flow chart of an example of setting the frequency output. That is, a high voltage control signal (PWM duty fixed, frequency is an initial value) is output from the control means 4, high voltage output is started from the high voltage generation circuit 3, and a high voltage is detected by the high voltage detection circuit 10. Then, a high voltage signal is input to the control means 4 to read the high voltage output. Next, the frequency is increased, and if the high voltage output increases when the frequency is increased, the frequency is further increased. If the high voltage output falls, the frequency is decreased. When the high voltage is increased by decreasing the frequency, the frequency is decreased until the high voltage is decreased. In this way, by changing the frequency and confirming that the high voltage rises / falls, the natural frequency of the high voltage generation circuit 3 is detected and the output frequency is determined.

In this way, even if the natural frequency of the high voltage generation circuit 3 varies depending on the individual , the control means 4 statically outputs the frequency output to the high voltage generation circuit 3 according to the specific frequency of the high voltage generation circuit 3. It can be set to be a high voltage necessary for electroatomization.

  Control that the frequency of the high voltage control signal is determined by repeatedly checking the rise / fall of the high voltage while searching for the natural frequency of the high voltage generation circuit 3 while changing the frequency as described above. Is performed by the control means 4.

FIG. 3 shows a control flow diagram of another embodiment of the present invention. In the present embodiment, a high voltage control signal (PWM duty fixed, frequency is an initial value) is output from the control means 4, high voltage output is started from the high voltage generation circuit 3, and the high voltage detection circuit 10 increases the high voltage. A voltage is detected, a high voltage signal is input to the control means 4 and a high voltage output is read. Next, when the frequency is increased by Δf by one step and the high voltage output when the frequency is increased by Δf decreases (the high voltage signal value decreases), the frequency is decreased by one step by Δf and the frequency is decreased by Δf. When the high voltage rises (high voltage signal value increases), the frequency is decreased by one step (Δf) until the high voltage decreases (high voltage signal value decreases). In this way, if the frequency is decreased step by step and the high voltage falls (the high voltage signal value decreases), it can be recognized that this is the frequency exceeding the peak frequency. The frequency is increased and only one is restored, and the frequency to be output is determined by regarding this frequency as the peak frequency.

On the other hand, in the control flow diagram of FIG. 3, the high voltage generation circuit 3 starts high voltage output, reads the high voltage output, and then increases the high voltage when the frequency is increased by one step by Δf ( When the high voltage signal value is increased), the frequency is increased by Δf, and when the frequency is increased by Δf, the high voltage is increased (when the high voltage signal value is increased), the high voltage is decreased (high voltage signal is increased). repeatedly increasing the frequency by one step (Delta] f) until the value decreases), lowering a high voltage when increasing the frequency (high voltage signal value decreases), the exceeded here Gapi over clock frequency Since it can be recognized that it is a frequency, next, the frequency is decreased by Δf by one step and returned to the original one, and this frequency is regarded as the peak frequency and the output frequency is determined.

  In this way, the control unit 4 performs control to search for a specific peak frequency (a frequency at which the high voltage output value is maximum) of the high voltage generation circuit 3 and determine the frequency of the high voltage control signal. This can ensure the optimum high voltage required for electrostatic atomization.

  FIG. 4 is a graph for explaining an example sequence for searching for a specific peak frequency of the high voltage generation circuit 3 according to the control flow of FIG.

  That is, when the initial value is (1), it is incremented by one step (Δf) and proceeds from (1) → (2)... (N). Then, the movement of the frequency change is reversed and Δf is decreased to (M), and this (M) is determined as the peak frequency to search for the inherent peak frequency of the high voltage generation circuit 3.

  The control of searching for the natural frequency of the high voltage generation circuit 3 and determining the frequency of the high voltage control signal as described above is automatically performed when the electrostatic atomizer 5 is initially set.

  The frequency of the high voltage control signal determined for each electrostatic atomizer 5 as described above is fixed thereafter when the electrostatic atomizer 5 is used, and when the electrostatic atomizer 5 is used, By controlling the frequency of the high voltage control signal output from the control means 4 to the high voltage generation circuit 3 and changing the duty ratio, the high voltage output from the high voltage generation circuit 3 is controlled to reach the target value. It is like that.

  In FIG. 1, an example of the Peltier unit 6 is shown as the water supply unit 2, but a cooling unit other than the Peltier unit 6 may be used. Further, the water in the air is not limited to supplying water as condensed water, and water may be supplied to the atomizing electrode from a water reservoir such as a tank by using capillary action or gravity. .

  In the embodiment of FIG. 1, the example in which the counter electrode 8 is provided has been described. However, the counter electrode 8 may not be provided.

It is a control block diagram of the electrostatic atomizer of this invention. It is a control flow figure of one embodiment same as the above. It is a control flowchart of other embodiment same as the above. It is a graph for demonstrating the order of an example which searches the intrinsic | native peak frequency which the high voltage generation circuit same as the above has.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Atomization electrode 2 Water supply means 3 High voltage generation circuit 4 Control means

Claims (3)

An atomizing electrode, water supply means for supplying water to the atomizing electrode, and a high voltage generating circuit for applying a high voltage to the atomizing electrode, and supplying the water supplied to the atomizing electrode to the high voltage in the electrostatic atomizing device for electrostatic atomization in a high electric field generated by the application of,
Control means for controlling the frequency output of the high voltage control signal to the pre-Symbol high voltage generating circuit is provided,
When the duty ratio of the high voltage control signal is maximized, the control means sets at least a frequency at which a high voltage necessary for electrostatic atomization is secured as a high voltage output from the high voltage generation circuit before use. Is automatically set as the frequency output of the high voltage control signal from the control means, and then the high voltage output from the high voltage generation circuit is reduced by changing the duty ratio. An electrostatic atomizer characterized by controlling so as to reach a high voltage required for electroatomization . 2. The electrostatic fog according to claim 1, wherein the control means controls the frequency output of the high voltage control signal from the control means so as to have a specific peak frequency of the high voltage generation circuit. Device. The electrostatic fog according to claim 1 or 2, wherein the control means controls the frequency output based on a high voltage output from the high voltage generation circuit when the frequency output is changed. Device.

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