JPH06320084A - Ultrasonic atomizing diaphragm - Google Patents

Abstract

PURPOSE:To provide an ultrasonic atomizing diaphragm which is given ultrasonic vibration by transmitting mechanical vibration from a piezoelectric vibrator. CONSTITUTION:Through-holes 2 are made in an ultrasonic atomizing diaphragm 1 having a lot of through-holes 2 and constituting a structure in the shape of a rectangular plate and the through-hole 2 has the form of a bowl. As one embodiment, the diameter of one opening is 100mum and that of the other is 10mum and through-holes are arranged at regular intervals of 140mum. In a peripheral edge part 3 with a width extending over 1mm is made no through-hole 2. Therefore, the sides have no unevenness and are not cracked even when the diaphragm is used for a long time. Gold plating is applied to allow the increase in chemical resistance. Therefore, in the case of being applied to an ultrasonic atomizer, the durability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an ultrasonic atomizing device used in a humidifier for controlling indoor humidity, and transmits the mechanical vibration from a piezoelectric vibrator which is excited by a high frequency voltage and mechanically vibrates. The present invention relates to a diaphragm that vibrates ultrasonically.

[0002]

2. Description of the Related Art An ultrasonic atomizer having an ultrasonic exciter having a structure in which a perforated diaphragm is fixed to a rectangular plate-shaped piezoelectric vibrator has been applied for a patent by Japanese Patent Application No. 2-273001.
In addition, a patent application of "Ultrasonic Color Organ" generated by applying the ultrasonic atomizer has been filed on April 22, 1991 (Japanese Patent Application No. 3-119191). The diaphragm used in these conventional ultrasonic atomizers is provided with a large number of through holes as a means for improving atomization efficiency in a direction substantially perpendicular to the plate surface.

FIG. 6 is a partially enlarged plan view showing an embodiment of a diaphragm in a conventional atomizing device as viewed from one plate surface. This example is made by cutting a large size nickel sheet obtained by electroforming.
The shape of each through hole provided in the direction perpendicular to the plate surface is a mortar shape, the opening area on one plate surface is larger than the opening area on the other plate surface, and the diameter of one opening is 100 μm and the other is 100 μm. Is 10 μm. The through holes are arranged at equal intervals with a spacing of 140 μm.

FIG. 7 is a side view of the diaphragm shown in FIG.
However, the side surface of the diaphragm obtained by cutting the nickel sheet is a cut surface that does not pass through the center of the through hole. Since there are irregular irregularities on the side surface, leaving a problem in mechanical strength when driving for a long time,
This will lead to deterioration of the spraying function. That is, there was a problem in durability.

FIG. 8 is a side view of the diaphragm shown in FIG.
However, the side surface of the diaphragm obtained by cutting the nickel sheet is a cut surface that passes through the center of the through hole. Since there is a crack corresponding to the diameter of the through hole on the side surface, mechanical strength is reduced by driving for a long time. This crack further expands due to repeated driving, which results in deterioration of the spraying function. That is, there was a problem in durability. Therefore, in order to prevent the cut surface from being uneven, it is necessary to devise such that the cut portion does not include the through hole, but this requires considerable precision and is difficult. Moreover, there is a possibility that the diaphragm itself will be bent and deformed by cutting. Cutting may be mentioned as another method of cutting the nickel sheet, but in cutting, since cutting powder blocks the through holes, a cleaning step is required to remove the cutting powder. Therefore, in terms of production technology, a large amount of labor is required for mass production.

Since the conventional diaphragm shown in FIGS. 6 to 8 is made of nickel, it has a problem in chemical resistance. When immersed in physiological saline, corrosion started to progress in about 2500 hours, resulting in deterioration of the function as a diaphragm.

[0007]

The conventional ultrasonic atomizing diaphragm has a problem in durability and requires a long labor for mass production in terms of production technology. There was also a problem with chemical resistance.

An object of the present invention is a thin film having mechanical strength capable of withstanding long-time driving, capable of mass production without requiring long-term labor, and having a chemical resistant surface. To provide an ultrasonic atomizing diaphragm covered with.

[0009]

The ultrasonic spray vibrating plate according to claim 1 has a plate-like structure having plate surfaces A and B which are substantially parallel to each other, and is surrounded by a peripheral portion and the peripheral portion. A part of the plate surface A is fixed to a piezoelectric vibrator that is composed of a spraying part and is excited by a high frequency voltage to cause mechanical vibration, so that the mechanical vibration is transmitted from the piezoelectric vibrator to generate ultrasonic vibration. An ultrasonic spray vibrating plate, wherein a large number of through holes are provided from the plate surfaces A to B, the through holes are provided in the spray section, and a sponge, a fiber bundle, etc. are provided at the entrance of the through holes. The liquid contained in the liquid retaining material is atomized when the hydrophilic liquid retaining material of (1) is brought close to the liquid retaining material.

The ultrasonic spray vibrating plate according to claim 2 is gold,
It is characterized in that the surface is covered with a thin film made of platinum, palladium, rhodium or other metal, or Teflon.

[0011]

The ultrasonic spray vibrating plate of the present invention is provided with a large number of through holes in a direction substantially perpendicular to the plate surface. Moreover, the through hole is provided within a predetermined range excluding the peripheral portion of the plate surface. That is, there is no unevenness on the side surface of the diaphragm. In this way, since the ultrasonic spray vibrating plate of the present invention has no cracks on its side surface, mechanical strength does not decrease due to long-time driving. Therefore, it becomes possible to maintain the spraying function of the spraying device using such a vibration plate. Further, by covering the surface with a thin film made of metal such as gold, platinum, palladium, rhodium or Teflon, chemical resistance can be improved. Therefore, by using such an ultrasonic spray vibrating plate of the present invention, it becomes easy to spray chemicals other than water.

[0012]

FIG. 1 is a partially enlarged plan view showing an embodiment of the ultrasonic spray vibrating plate of the present invention seen from one plate surface. The ultrasonic spray vibrating plate 1 shown in this embodiment is made of nickel and has a rectangular plate-like structure having a large number of through holes 2. The through hole 2 is provided in a direction perpendicular to the plate surface, and its shape is a mortar shape. The opening area of one plate surface is larger than the opening area of the other plate surface, and the diameter of one opening is 10 mm.
0 μm, and the other is 10 μm. Through hole 2 is 140 μm
Are arranged at equal intervals with a space of. A peripheral portion 3 is provided on the plate surface over a width of 1 mm.
The through hole 2 is not opened in the.

FIG. 2 is a side view of the ultrasonic spray vibrating plate 1 of FIG. There is no unevenness on the side surface, and the adjoining portion of the two side surfaces is a curved line, and the curved line has an arc shape.

FIG. 3 is a plan view showing an embodiment in which the ultrasonic spray vibrating plate 1 of FIG. 1 is molded from an electrode plate with a photoresist. In this embodiment, the electrode plate 4 having a thickness of 50 μm is used.
4 sheets of ultrasonic spray vibration plates 1 having a length of 17 mm and a width of 20 mm are formed. Each ultrasonic spray vibrating plate 1 is provided with a peripheral portion 3 having a width of 1 mm. Further, although FIG. 3 shows an example in which the rectangular plate-shaped ultrasonic spray vibrating plate 1 is formed, the ultrasonic spray vibrating plate having a disc shape or other shapes can be similarly formed by the photoresist.

FIG. 4 is a sectional view showing an embodiment in which the surface of the ultrasonic spray vibrating plate 1 of FIG. 1 is plated with gold. The gold plating on the ultrasonic spray vibrating plate 5 shown in this embodiment is about 1 μm in the surface layer and 0.1 to 0.2 in the through hole 2.
The thickness is μm. When the ultrasonic spray vibrating plate 5 is dipped in a flux (solvent mainly composed of isopropyl alcohol for improving solderability), 21
It took 84 hours. It was confirmed that the corrosion resistance is improved by the gold plating because the corrosion occurrence time is 800 hours when the gold plating is not applied. If the corrosion resistance of the ultrasonic spray vibration plate 5 is improved, not only the chemical liquid can be sprayed without lowering the spraying function, but also the raw material (nickel in this embodiment) of the ultrasonic spray vibration plate 5 and the chemical liquid to be sprayed. The chemical reaction of can be prevented. Further, although gold is used as the metal used for plating in this embodiment, platinum, palladium, rhodium or the like can be used in addition to gold. It is possible to use not only metal but also a thin film made of Teflon such as CYTOP (product name) made by Asahi Glass.

FIG. 5 is a perspective view showing an embodiment of an ultrasonic spraying device composed of the ultrasonic spraying vibrating plate 5 and the piezoelectric vibrator 6 of FIG. The piezoelectric vibrator 6 has a rectangular plate-shaped piezoelectric ceramic 7, and the material of the piezoelectric ceramic 7 is TDK72A material (product name).
Its length is 22 mm, its width is 20 mm, and its thickness is 1 mm. Since the TDK72A material has a large electromechanical coupling coefficient, it is used in this example. The direction of the polarization axis of the piezoelectric ceramic 7 coincides with the thickness direction, and Au electrodes 8 and 9 are formed on both end faces perpendicular to this thickness direction. Au
The electrode 8 covers one surface of the piezoelectric ceramic 7 and the Au electrode 9 covers the other surface of the piezoelectric ceramic 7. Piezoelectric vibrator 6
Is soldered to one end surface of the ultrasonic spray vibration plate 5 through the Au electrode 8 so as to be integrally connected to the ultrasonic spray vibration plate 5. At the time of this solder bonding, cream solder is applied to the bonding portion of the piezoelectric vibrator 6 with the ultrasonic spray vibration plate 5. With respect to the ultrasonic spray vibrating plate 5, the gold plating preliminarily applied to the ultrasonic spray vibrating plate 5 also serves as solder plating, so that the bonding time between the ultrasonic spray vibrating plate 5 and the piezoelectric vibrator 6 can be shortened.

When the ultrasonic spraying device of FIG. 5 is driven, when an AC signal having a frequency substantially equal to the resonance frequency of the composite of the ultrasonic spray vibrating plate 5 and the piezoelectric vibrator 6 is applied to the piezoelectric vibrator 6, the piezoelectric vibrator 6 vibrates. Child 6 is excited. At this time, the frequency of the AC signal substantially matches one of the resonance frequencies of the piezoelectric vibrator 6 alone. Since the ultrasonic spray vibrating plate 5 has a structure in which it is integrally connected and fixed to at least one end face of the piezoelectric vibrator 6, the ultrasonic spray vibrating plate 5 is excited when the piezoelectric vibrator 6 is excited. Ultrasonic spray vibration plate 5
The piezoelectric vibrator 6 is vibrated in such a manner that the fixed portion of the piezoelectric vibrator 6 serves as a fixed end. When the liquid is supplied to the ultrasonic spray vibrating plate 5, the liquid is guided to the through hole 2 provided in the ultrasonic spray vibrating plate 5 by a capillary phenomenon. The liquid becomes fine and uniform particles, flows out to the outlet side of the through hole 2, and is efficiently atomized.

[0018]

According to the ultrasonic spray vibrating plate of the present invention, a large number of through holes provided in the direction substantially perpendicular to the plate surface are limited within a predetermined range excluding the peripheral portion of the plate surface. That is, there is no unevenness on the side surface of the diaphragm. In this way, the ultrasonic spray vibrating plate of the present invention has no cracks on its side surface and the mechanical strength does not decrease. Therefore, the spraying device using the ultrasonic spray vibrating plate of the present invention can maintain the spraying function even when used for a long time. Also, the surface is gold, platinum,
Chemical resistance can be improved by covering with a thin film made of metal such as palladium, rhodium or Teflon. Therefore, by using the ultrasonic spray vibrating plate of the present invention, it becomes easy to spray chemicals other than water without impairing the quality. In terms of production technology, when the ultrasonic spray diaphragm whose surface is covered with a thin film made of the metal or Teflon is soldered to a piezoelectric vibrator to form a spray device, the ultrasonic spray is used. Since it is not necessary to apply solder plating to the vibration plate, mass production of the spraying device can be facilitated.

[Brief description of drawings]

FIG. 1 is a partially enlarged plan view showing an embodiment of an ultrasonic spray vibrating plate of the present invention when viewed from one plate surface.

FIG. 2 is a side view of the ultrasonic spray vibration plate 1 of FIG.

FIG. 3 is a plan view showing an embodiment in which the ultrasonic spray vibrating plate 1 of FIG. 1 is molded from an electrode plate with a photoresist.

FIG. 4 is a cross-sectional view showing an embodiment in which the surface of the ultrasonic spray vibration plate 1 of FIG. 1 is gold-plated.

5 is a perspective view showing an embodiment of an ultrasonic spraying device composed of the ultrasonic spraying vibration plate 5 and the piezoelectric vibrator 6 of FIG.

FIG. 6 is a partially enlarged plan view showing an embodiment when a diaphragm in a conventional atomizing device is viewed from one plate surface.

FIG. 7 is a side view of the diaphragm shown in FIG.

FIG. 8 is a side view of the diaphragm shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic spray vibration plate 2 Through hole 3 Peripheral part 4 Electrode plate 5 Ultrasonic spray vibration plate 6 Piezoelectric vibrator 7 Piezoelectric ceramics 8 Au electrode 9 Au electrode

Claims (2)

[Claims] 1. A piezoelectric device having a plate-like structure having plate surfaces A and B substantially parallel to each other, comprising a peripheral edge portion and a spraying portion surrounded by the peripheral edge portion, and which is excited by a high-frequency voltage to mechanically vibrate. An ultrasonic spray vibration plate, wherein a part of the plate surface A is fixed to the vibrator to transmit the mechanical vibration from the piezoelectric vibrator to perform ultrasonic vibration. The through hole is provided in the spraying section, and a sponge, a fiber bundle or other hydrophilic liquid retaining material is brought close to the inlet of the through hole to thereby retain the liquid retaining material. An ultrasonic atomizing diaphragm, characterized in that the liquid contained therein is atomized. 2. The ultrasonic spray vibrating plate according to claim 1, wherein the surface is covered with a thin film made of metal such as gold, platinum, palladium, rhodium or Teflon.