JP2008207057A - Ultrasonic atomizing device and equipment provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic atomizing device capable of stably atomizing a liquid even if the oscillation of the ultrasonic vibrator is suppressed due to a liquid to be atomized and equipment provided with the same. <P>SOLUTION: The ultrasonic atomizing device 10 is structured by a piezoelectric element and is provided with a PZT vibrator 13 generating ultrasonic wave having 20-80 kHz frequency band and a tacky adhesive layer provided in the outer peripheral edge face of the PZT vibrator 13 and capable of suppressing the oscillation of the PZT vibrator 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultrasonic atomizer that can atomize a liquid using ultrasonic waves, and an equipment that includes the ultrasonic atomizer, and in particular, an ultrasonic atomizer that can stably atomize a liquid, and It relates to equipment equipped with it.

  Conventionally, there is an ultrasonic atomization device that atomizes a liquid by an ultrasonic atomization technique. Such an ultrasonic atomizer applies a pulse voltage to a PZT (lead zirconate titanate) vibrator, which is a piezoelectric element, and oscillates the PZT vibrator to generate ultrasonic waves to atomize the liquid. ing. Such an ultrasonic atomizer is used for medical applications such as nebulization of medicines and disinfectants (for example, nebulizers (inhalers)), and for air conditioning applications such as humidifying indoor air. There are many uses.

  As such, “from an ultrasonic transducer made of a piezoelectric body, a liquid container containing a liquid, and a water absorption band in which one end is inserted into the liquid container and the other end is in contact with the entire vibration end surface of the ultrasonic transducer. There has been proposed an ultrasonic atomizer configured to become “see” (for example, see Patent Document 1). This ultrasonic atomizer sucks up the liquid in the water absorption zone, supplies it directly to the ultrasonic vibrator, atomizes the liquid, and sprays the atomized liquid (hereinafter simply referred to as atomized liquid). It is what.

JP 2003-181347 A (3rd page, FIG. 1)

  However, in the ultrasonic atomizer described in Patent Document 1, when an atomizing liquid (for example, water) is directly supplied to the ultrasonic vibrator, the ultrasonic vibrator oscillates due to the weight of the liquid. As a result, the acoustic characteristics of the ultrasonic transducer move to a lower frequency band, and the frequency of the original acoustic characteristics of the ultrasonic transducer cannot be obtained. Problems such as trapping and stopping the atomization of the liquid itself would occur.

  The present invention has been made in order to solve the above-described problems. Even when the oscillation of the ultrasonic vibrator is suppressed by the atomizing liquid, the ultrasonic wave capable of stably atomizing the liquid is provided. An atomization apparatus and equipment provided with the same are provided.

  An ultrasonic atomizing device according to the present invention is an ultrasonic atomizing device that atomizes a liquid by ultrasonic waves. The ultrasonic atomizing device includes a piezoelectric element that generates ultrasonic waves, and an outer peripheral surface of the vibrator. And an adhesive layer that suppresses oscillation of the vibrator. Moreover, the equipment according to the present invention includes the above-described ultrasonic atomizer.

  The ultrasonic atomizing apparatus according to the present invention includes a piezoelectric element, and an adhesive layer is provided on the outer peripheral surface of the vibrator that generates ultrasonic waves. Therefore, the vibration of the vibrator can be suppressed in advance. It is possible to make the range having the peak of the ultrasonic wave generated from a relatively flat characteristic tendency, and it is possible to atomize the liquid within this range. Therefore, it is possible to stably atomize the liquid. Moreover, since the installation apparatus which concerns on this invention is equipped with said ultrasonic atomizer, it has all the effects of an ultrasonic atomizer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a schematic configuration of an ultrasonic atomizer 10 according to an embodiment of the present invention. Based on FIG. 1, the structure of the ultrasonic atomizer 10 is demonstrated. This ultrasonic atomizer 10 atomizes liquids such as water and chemicals by generating ultrasonic waves. FIG. 1A shows a longitudinal sectional view of the ultrasonic atomizing device 10, and FIG. 1B shows a plan view of the ultrasonic atomizing device 10. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one.

  The ultrasonic atomizer 10 is characterized in that the atomized liquid can be stably supplied. As shown in FIG. 1A, the ultrasonic atomizer 10 is configured by laminating a support portion 11, a pedestal 12, and a PZT vibrator 13 in order. An adhesive layer 15 is provided on the outer peripheral surface of the PZT vibrator 13 (that is, the peripheral edge of the PZT vibrator 13). The PZT vibrator 13 and the pedestal 12 are covered with a structure 14 around the periphery. And the holding | maintenance part 16 of the shape according to the shape of the adhesion layer 15 is formed in the surface (henceforth only an upper surface) on the opposite side to the base 12 side of this structure 14 (refer FIG. 2). In addition, you may form the support part 11 and the structure 14 integrally.

  The support part 11 is for attaching the ultrasonic atomizer 10 to the housing | casing etc. of the installation apparatus with which the ultrasonic atomizer 10 is installed. As shown in FIG. 1B, the support portion 11 has a circular planar shape. In addition, the support part 11 is not limited to circular shape, What is necessary is just the shape according to the equipment with which the ultrasonic atomizer 10 is attached. The pedestal 12 is attached to one side (the upper side in the drawing) of the support portion 11 and is for fixing the PZT vibrator 13. The pedestal 12 also has a circular planar shape like the support portion 11, but the planar shape is not limited to a circular shape.

  The PZT vibrator 13 is a piezoelectric element made of lead zirconate titanate, and oscillates when a pulse voltage is applied via the positive electrode terminal portion 17 and the negative electrode terminal portion 18. In other words, the PZT vibrator 13 has a circular planar shape, and is applied with a sound wave in a predetermined frequency band (a general frequency band of 20 kHz to 80 kHz) by applying a pulse voltage. It has a function as an ultrasonic transducer that generates ultrasonic waves. Here, a case where one PZT transducer 13 is provided in the ultrasonic atomizer 10 is shown as an example, but a plurality of PZT transducers 13 may be provided in the ultrasonic atomizer 10. If a bimorph structure is formed by laminating a plurality of PZT vibrators 13, the oscillation of the PZT vibrator 13 can be made stronger.

  FIG. 1 shows an example in which the positive electrode terminal portion 17 and the negative electrode terminal portion 18 penetrate the support portion 11 and the pedestal 12 and are connected to the PZT vibrator 13. However, the present invention is not limited to this, and may be connected to the PZT vibrator 13 without penetrating the support portion 11 and the base 12. The planar shape of the PZT vibrator 13 is also circular like the support portion 11 and the pedestal 12, but the planar shape is not limited to a circular shape, and may be a polygonal shape.

  In the structure 14, a holding portion 16 having a shape corresponding to the shape of the peripheral end portion of the PZT vibrator 13 is formed on the upper surface, and an outer periphery of the PZT vibrator 13 is provided by providing an adhesive layer 15 on the holding portion 16. Is supposed to hold. In addition, the structure 14 has a circular planar shape, and holds the PZT vibrator 13 and has an internal space, and the lower end of the side surface supports the pedestal 12 in the internal space. It can be attached to the part 11. A metal resonator may be used as the structure 14.

  If a resonator is used as the structure 14, it can be resonated by the oscillation of the PZT vibrator 13, and the primary vibration mode of the frequency of the ultrasonic wave generated by the oscillation of the PZT vibrator 13 (broken line A shown in FIG. 1A). ) Can cause a resonance phenomenon and amplify the oscillation of the PZT vibrator 13. Further, if the exposed surface of the PZT vibrator 13 is covered with the structure 14 that is a resonator, the PZT vibrator 13 can be protected without bringing the PZT vibrator 13 into direct contact with the liquid. .

In addition, the material which comprises the structure 14 is not specifically limited. For example, if a metal resonator is used as the structure 14, the material may be determined according to the application of the ultrasonic atomizer 10, particularly the liquid to be atomized. If the ultrasonic atomizer 10 is used for sterilization by using a chemical (for example, H ₂ O ₂ (hydrogen peroxide solution)) as the liquid, the structure 14 can be prevented from being corroded by the chemical. Such a metal material (for example, an alloy of nickel (Ni) and copper (Cu)) may be used. Then, the progress of corrosion due to the chemical can be prevented.

  The adhesive layer 15 is provided on the outer peripheral surface of the PZT vibrator 13 and forcibly suppresses the oscillation of the PZT vibrator 13. Therefore, it is desirable that the adhesive layer 15 is made of a material having vibration-proof performance. For example, the pressure-sensitive adhesive layer 15 may be formed of a pressure-sensitive adhesive material (for example, rubber or urethane) having vibration-proof performance. The adhesive layer 15 is configured to fix the PZT vibrator 13 to the holding portion 16 provided on the upper surface of the structure 14. That is, in order to suppress the oscillation of the PZT vibrator 13, the PZT vibrator 13 has a function of fixing to the structure 14.

  FIG. 2 is a longitudinal sectional view for explaining the holding portion 16 formed in the structure 15. Based on FIG. 2, the holding | maintenance part 16 currently formed in the structure 15 is demonstrated. The holding portion 16 formed on the upper surface of the structure 15 is for holding the PZT vibrator 13 via the adhesive layer 15 provided on the outer peripheral surface of the PZT vibrator 13. Therefore, the holding part 16 is preferably formed to have a diameter larger than the outer diameter of the PZT vibrator 13. Further, as shown in FIG. 2, the wall surface of the structure 15 of the holding portion 16 is formed so as to be curved, so that the adhesive layer 14 can be easily accommodated. The upper surface of the structure 14 may be simply cut out to form the holding portion 16, and the wall surface of the structure 15 of the holding portion 16 may be formed in a staircase shape.

  FIG. 3 is a graph showing the acoustic characteristics of the PZT vibrator 13. Based on FIG. 3, the operation of the ultrasonic atomizer 10 will be described, and the acoustic characteristics of the PZT vibrator 13 will be described by comparing the case where the adhesive layer 15 is provided with the case where the adhesive layer 15 is not provided. In FIG. 3, the horizontal axis represents frequency (Hz) and the vertical axis represents sharpness (Q). Further, the solid line A shows the sharpness curve of the PZT vibrator 13 when the adhesive layer 15 is not provided, and the wavy line B shows the sharpness curve of the PZT vibrator 13 when the adhesive layer 15 is provided.

  First, radiation of the atomized liquid will be briefly described. As described above, when a voltage is applied to the PZT vibrator 13, the PZT vibrator 13 oscillates and ultrasonic waves are generated from the exposed surface of the PZT vibrator 13. By this ultrasonic wave, the liquid present on the exposed surface of the PZT vibrator 13 is atomized and emitted. In the case where the structure 14 is formed of a resonator, the resonance phenomenon of the resonator generated by the primary vibration mode of the ultrasonic wave generated from the PZT vibrator 13 can be used. In other words, a resonance wave having a resonance frequency of the primary resonance mode is generated from the structure 14 due to the resonance phenomenon, and the liquid can be atomized and radiated by the resonance wave.

  At this time, the oscillation of the PZT vibrator 13 is suppressed by the weight of the liquid present on the exposed surface of the PZT vibrator 13, and the original acoustic characteristics of the PZT vibrator 13 cannot be obtained. The sharpness (Q) indicates a tendency of acoustic characteristics representing the oscillation state of the PZT vibrator 13, and when a reliable oscillation phenomenon occurs, it shows a tendency to have a steep peak (in FIG. 3). Solid line A) shown. When the sharpness (Q) is in a range having a steep peak (Fc shown in FIG. 3), the liquid is atomized. That is, if the oscillation of the PZT vibrator 13 is suppressed by the liquid, a steep peak will not occur, and the amount of atomized liquid will decrease, or the atomization of the liquid itself will stop. is there.

  Therefore, in the ultrasonic atomizer 10 according to this embodiment, the adhesive layer 15 is provided on the outer peripheral surface of the PZT vibrator 13 to suppress the oscillation of the PZT vibrator 13 in advance. That is, as indicated by the broken line B shown in FIG. 3, the range having the peak (Fr shown in FIG. 3) is widened. Thus, if the range having peaks exhibits a relatively flat characteristic tendency, the liquid can be atomized within this range. That is, even if the oscillation of the PZT vibrator 13 is suppressed by the weight of the liquid, since the range having a steep peak is wide, it is possible to atomize the liquid within this range. Therefore, the ultrasonic atomizer 10 can stably atomize the liquid.

  Furthermore, if the oscillation of the PZT vibrator 13 is suppressed in advance by the adhesive layer 14, the range having a peak in the acoustic characteristics of the PZT vibrator 13 has a relatively flat characteristic tendency in advance. Therefore, even if the liquid is supplied to the exposed surface of the PZT vibrator 13 and the acoustic characteristics change due to the weight of the liquid, a predetermined amount of atomized liquid is ensured within a previously widened range. It can be done. Therefore, the ultrasonic atomizer 10 can stably atomize the liquid.

  Since the liquid directly contacts the PZT vibrator 13, the PZT vibrator 13 may be rusted or corroded depending on the liquid, and the PZT vibrator 13 may be damaged. Therefore, it is desirable that the exposed surface of the PZT vibrator 13 be subjected to an electrode treatment with an alloy of nickel (Ni) and copper (Cu) having corrosion resistance. A silicon film may be formed on the exposed surface of the PZT vibrator 13. Further, if the bimorph structure is formed by laminating a plurality of PZT vibrators 13, the oscillation of the PZT vibrator 13 can be made stronger.

  In order to suppress the oscillation of the PZT vibrator 13 in advance, the case where the structure 14 for holding the PZT vibrator 13 is provided in the ultrasonic atomizer 10 has been described as an example. However, the present invention is not limited to this. As an extreme example, even if the PZT vibrator 13 is not held by the structure 14, it suffices if the oscillation of the PZT vibrator 13 can be suppressed in advance only by the adhesive layer 14. However, in order to reliably suppress the oscillation of the PZT vibrator 13, it is desirable to hold the PZT vibrator 13 by providing not only the adhesive layer 14 but also the structure 14 in which the holding portion 16 is formed.

  FIG. 4 is an explanatory diagram for explaining an installation example of the ultrasonic atomizer 10. Based on FIG. 4, the installation example of the ultrasonic atomizer 10 is demonstrated. In FIG. 4, the case where the ultrasonic atomizer 10 is installed in the atomizing duct 20 is shown as an example. As shown in FIG. 4, when the ultrasonic atomizer 10 radiates liquid, the atomizing liquid (hereinafter simply referred to as source water 22) is supplied from the source water tank 21 into the atomization duct 20. Supplied. When the source water 22 reaches the exposed surface of the PZT vibrator 13 inside the atomizing duct 20, the atomization of the source water 22 is started.

  That is, a pulse voltage is applied to the PZT vibrator 13 via the positive electrode terminal portion 17 and the negative electrode terminal portion 18 connected to the PZT vibrator 13, and the PZT vibrator 13 oscillates to generate ultrasonic waves. The source water 22 that fills the exposed surface of the PZT vibrator 13 is atomized by the ultrasonic waves generated by the PZT vibrator 13. The atomizing duct 20 functions as an ultrasonic waveguide, and the ultrasonic vibration wave generated from the ultrasonic atomizing device 10 is propagated in the atomizing duct 20. Therefore, by installing the ultrasonic atomizing device 10 in the atomizing duct 20, there is no propagation of air from the outside of the atomizing duct 20, and attenuation of ultrasonic waves can be reduced.

  That is, the ultrasonic wave generated from the PZT vibrator 13 propagates through the atomizing duct 20 while repeating the density. By installing the ultrasonic atomizer 10 in the atomizing duct 20 in this way, attenuation of ultrasonic waves generated from the PZT vibrator 13 can be reduced, and the length of the atomizing duct 20 is increased. However, the ultrasonic vibration wave can be propagated over a long distance. Therefore, the ultrasonic atomizing device 10 can be installed in the atomizing duct 20 in accordance with the application of the equipment in which the ultrasonic atomizing device 10 is installed.

  As equipment that can install the ultrasonic atomizer 10 according to this embodiment, for example, an indoor unit of an air conditioner such as an air conditioner or a freezer, a nebulizer (inhaler), a deodorizer, a sprayer, a humidifier, There are refrigerators. That is, the ultrasonic atomizer 10 can be installed in any equipment that needs to atomize and emit liquid. Moreover, when the ultrasonic atomizer 10 is provided in an indoor unit, it can be used for the sterilization use in an indoor unit, and when the ultrasonic atomizer 10 is provided in a refrigerator, the food in a warehouse is dried. It can also be used so that it does not. In addition, what is necessary is just to install the duct 20 for atomization according to the installation apparatus which installs the ultrasonic atomizer 10. FIG.

  In the embodiment, the PZT vibrator 13 is described as an example of the piezoelectric element. However, the present invention is not limited to this. For example, a piezoelectric element such as a ceramic piezoelectric element or a polymer piezoelectric element may be used. Further, the atomizing duct 20 may be configured in a cylindrical shape, may be configured in a prismatic shape, and the inside may be hollowed out in a cylindrical shape. In this case, the support portion 11 may also have a shape corresponding to the shape of the atomizing duct 20.

It is a schematic block diagram which shows schematic structure of the ultrasonic atomizer which concerns on embodiment. It is a longitudinal cross-sectional view for demonstrating the holding | maintenance part currently formed in the structure. It is a graph showing the acoustic characteristic of a PZT vibrator. It is explanatory drawing for demonstrating the installation example of an ultrasonic atomizer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Ultrasonic atomization apparatus, 11 Support part, 12 base, 13 PZT vibrator, 14 Structure, 15 Adhesive layer, 16 Holding part, 17 Positive electrode terminal part, 18 Negative electrode terminal part, 20 Atomization duct, 21 Source water tank, 22 Source water.

Claims (6)

An ultrasonic atomizer that atomizes a liquid by ultrasonic waves,
A vibrator composed of piezoelectric elements and generating ultrasonic waves;
An ultrasonic atomizing device comprising: an adhesive layer provided on an outer peripheral surface of the vibrator and suppressing oscillation of the vibrator. The ultrasonic atomizer according to claim 1, wherein the adhesive layer is made of rubber or urethane. The ultrasonic atomizer according to claim 1, further comprising: a structure that holds the vibrator via the adhesive layer. The ultrasonic atomizer according to claim 3, wherein the structural body is formed of a metal resonator. The ultrasonic atomizer according to any one of claims 1 to 4, wherein the exposed surface of the vibrator is electrode-treated with a corrosive metal alloy. The equipment provided with the ultrasonic atomizer in any one of the said Claims 1-5.

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