JPH0763379A - Ultrasonic atomizer - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an ultrasonic spraying device for atomizing a liquid from a vibrating plate fixed to a piezoelectric vibrator by bringing a hydrophilic liquid retaining material into contact with the vibrating plate. [Structure] When a composite body including a piezoelectric vibrator 9 and a diaphragm 10 is driven, the piezoelectric vibrator 9 vibrates, and the vibration is propagated to the diaphragm 10. The liquid supplied to the diaphragm 10 is atomized through the through holes 14 as the diaphragm 10 vibrates.
When the vibrating plate 10 is fixed to the piezoelectric vibrator 9, the fixing agent is also incorporated in a small space between the vibrating plate 10 and the side surface of the piezoelectric vibrator 9. In this way, the coupling strength between the vibration plate 10 and the piezoelectric vibrator 9 is further increased. [Effect] Since the coupling between the piezoelectric vibrator and the vibration plate can be made stronger, atomization efficiency can be promoted and durability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic spraying device used in a humidifier for controlling indoor humidity.

[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 is 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).

FIG. 5 is a sectional view showing an embodiment of a conventional ultrasonic atomizer, and FIG. 6 is a sectional view of the embodiment shown in FIG. 5 as seen from the diaphragm side. When the piezoelectric vibrator is excited during driving of the ultrasonic atomizing device of the present embodiment, the vibration is propagated to the diaphragm fixed to the piezoelectric vibrator. A liquid retaining material is provided on the lower surface of the diaphragm. The liquid absorbed by the liquid retaining material and reaching the diaphragm is atomized through a large number of minute holes provided in the diaphragm. Since the vibration plate is provided on the lower surface of the piezoelectric vibrator, the pressure from below on the vibration plate is relieved. Supports are provided on both sides of the liquid retaining material. The support is fixed to the case and faces the lower surface of the diaphragm with a minute gap (1 to 2 mm). Since such a support is provided, the pressure from above on the diaphragm is relieved. In this way, the present embodiment has a structure in which the vibration plate is somewhat unlikely to separate from the piezoelectric vibrator. However, the maximum peel strength of the vibration plate with respect to the piezoelectric vibrator in this example was about 0.5 kgf, and no measure was taken to enhance the coupling itself between the piezoelectric vibrator and the vibration plate. In addition, in order to compensate for the drawback that the fixed portion between the piezoelectric vibrator and the diaphragm is easily peeled off, a hole is formed through the fixed portion, and a bolt is inserted into the hole to tighten the piezoelectric vibrator and the diaphragm. Although a method for preventing the peeling of the piezoelectric element has been devised, such a conventional method has hindered the vibration of the piezoelectric vibrator, resulting in a decrease in the atomization function.

[0004]

In the conventional ultrasonic atomizing device, the strength of the connection between the piezoelectric vibrator and the diaphragm was not sufficient. Moreover, it was difficult to improve the strength of the coupling between the piezoelectric vibrator and the diaphragm without lowering the atomization function.

An object of the present invention is to provide an ultrasonic spraying device capable of preventing peeling of a fixed portion between a piezoelectric vibrator and a vibrating plate without inhibiting vibration of the piezoelectric vibrator and improving an atomizing function. To do.

[0006]

An ultrasonic spraying apparatus according to claim 1, wherein a vibrating plate having a hole fixed to a piezoelectric vibrator is brought into contact with a sponge, a fiber bundle or other hydrophilic liquid retaining material to vibrate. In an ultrasonic atomizing device for atomizing a liquid from a plate, the piezoelectric vibrator includes a substantially rectangular plate-shaped piezoelectric ceramic and electrodes P and Q fixed to the piezoelectric ceramic, the electrode P being the thickness of the piezoelectric ceramic. The electrode Q is provided on a part of the end surface A of the both end surfaces A and B perpendicular to the vertical direction, and the electrode Q is a part F of the surface adjacent to the end surfaces A and B of the piezoelectric ceramic.
From the end face B to the end face B, the electrodes P and Q are in an insulated state from each other, and the vibrating plate passes through the electrode Q on the end face B near the boundary line between the part F and the end face B. A reinforcing member fixed to the piezoelectric vibrator, one of which is fixed to the portion F near the boundary line and the other of which is fixed to the diaphragm near the boundary line between the portion F and the diaphragm. It is characterized in that it is provided between.

According to another aspect of the ultrasonic spraying device of the present invention, the piezoelectric ceramic is provided on one of the 12 sides of the rectangular plate.
The end face B is adjacent to the surface S of the part where the columnar structure is cut off in the piezoelectric ceramic, and the surface S Is included in the portion F.

[0008]

In the ultrasonic spraying device of the present invention, a sponge, a fiber bundle or other hydrophilic liquid retaining material is brought into contact with a perforated diaphragm fixed to a piezoelectric vibrator, and the liquid contained in the hydrophilic liquid retaining material is brought into contact with the vibrating liquid. It has a structure that atomizes from a large number of minute holes provided in the diaphragm. The piezoelectric vibrator includes a substantially rectangular plate-shaped piezoelectric ceramic and electrodes P and Q fixed to the piezoelectric ceramic. As the piezoelectric ceramic, it is possible to provide a structure having both end surfaces A and B perpendicular to the thickness direction of the piezoelectric ceramic and four side surfaces adjacent to the both end surfaces A and B. The electrode P is provided on a part of the end face A. The electrode Q is provided from a part F of the four side surfaces to the end surface B. For example, one side C
To the end face B are adopted, and at this time, the electrode Q has a structure straddling two mutually perpendicular faces (side face C and end face B). The electrodes P and Q are insulated from each other. When the vibration plate is fixed to the piezoelectric vibrator, the electrode Q on the end face B near the boundary line between the side face C and the end face B is used.
Stick through. The vibration plate is integrally connected to the piezoelectric vibrator by soldering or by using a conductive adhesive. At this time, the bonding agent is filled and solidified even in a small space between the side surface C near the boundary line and the vibration plate perpendicular to the side surface C to further bond the piezoelectric vibrator and the vibration plate. It can be strong. At this time, this bonding agent that fills a small space between the side surface C and the diaphragm functions as a reinforcing material. In this way, peeling between the piezoelectric vibrator and the diaphragm can be suppressed. Moreover, since the vibration of the piezoelectric vibrator is not hindered, the atomization function is not deteriorated.

As the piezoelectric ceramic, it is possible to employ a structure in which one of twelve sides of a rectangular plate has a columnar structure whose height is one side and is cut off from the rectangular plate. For example, it is possible to provide a piezoelectric ceramic having a structure in which a triangular prism having a height at the boundary line between the side surface C and the end surface B is cut off and cut out from a rectangular plate. In such a piezoelectric ceramic, the side surface C and the end surface B are
A new surface S is formed between and. That is, the electrode Q
Is provided over the end surface B, the surface S, and the side surface C.

[0010]

1 is a sectional view showing an embodiment of an ultrasonic spraying device of the present invention. This embodiment comprises a system unit 1, a spring 2, a nozzle 3, a liquid absorbing material 4, a liquid storage chamber 5, a housing 6, a cover 7 and a battery 8. The system unit 1 includes a piezoelectric vibrator 9, a diaphragm 10 and a drive circuit 11, which are housed in a case 12. The upper end of the case 12 is fixed to the cover 7. The liquid absorbent material 4 is fixed to the liquid storage chamber 5. The liquid storage chamber 5 is filled with liquid at the time of use, and substantially the lower half of the liquid absorbent material 4 is immersed in the liquid. The liquid absorbent material 4 is made of acetate fiber or the like.

FIG. 2 is a partial sectional view showing a first embodiment of the system unit 1. The piezoelectric vibrator 9 includes a rectangular plate-shaped piezoelectric ceramic 13 and electrodes P and Q. The piezoelectric ceramic 13 has a structure in which one of twelve sides of the rectangular plate is cut out from the rectangular plate with a columnar structure having a height on one side as a defect, and the cut portion has a rounded cut end. There is. The electrode Q is provided from the upper end surface of the piezoelectric ceramic 13 to the cut and the side surface below and adjacent to the cut. The electrode P is provided on almost the entire lower end surface of the piezoelectric ceramic 13 so that the electrodes P and Q are in an insulated state. Diaphragm 1
0 has a large number of minute through holes 14 (not shown in FIG. 2). The vibration plate 10 is soldered to the upper end surface of the piezoelectric vibrator 9. At this time, the bonding agent is also incorporated in a small space between the vibration plate 10 and the side surface of the piezoelectric vibrator 9. In this way, the diaphragm 10 and the piezoelectric vibrator 9
The bond strength with is further increased. The peel strength of the diaphragm 10 with respect to the piezoelectric vibrator 9 was a value of 5.0 kgf or more.

FIG. 3 is a partial sectional view showing a second embodiment of the system unit 1. In this embodiment, the cut in FIG. 2 is a flat surface. Also in this example, the same effect as in FIG. 2 was observed.

FIG. 4 is a partial cross-sectional view showing a third embodiment of the system unit 1. This embodiment differs from the embodiment of FIG. 2 or 3 in that the piezoelectric ceramic 13 has no defect. Also in this example, the same effect as in FIG. 2 or FIG. 3 was observed.

When the ultrasonic spraying device of FIG. 1 is driven, when an AC signal having a frequency substantially equal to the resonance frequency of the composite of the piezoelectric vibrator 9 and the vibration plate 10 is applied to the piezoelectric vibrator 9, the piezoelectric vibrator 9 is driven. Be excited. At this time, the frequency of the AC signal substantially matches one of the resonance frequencies of the piezoelectric vibrator 9 alone. Since the vibrating plate 10 has a structure in which at least one end face of the piezoelectric vibrator 9 is integrally connected and fixed, the vibrating plate 10 vibrates with the piezoelectric vibrator 9 as the piezoelectric vibrator 9 is excited. The plate 10 is vibrated in such a manner that the fixed portion to the plate 10 serves as a fixed end. When the liquid is supplied to the diaphragm 10 from the liquid absorbing material 4, the liquid is vibrated by the capillary phenomenon.
Is guided to the through hole 14 provided in the. The area of the through hole 14 on the inlet side is set to be larger than the area on the outlet side. Therefore, the liquid introduced to the inlet side of the through hole 14 becomes fine and uniform particles, flows out to the outlet side of the through hole 14, and is efficiently atomized. Moreover, since the degree of coupling between the piezoelectric vibrator 9 and the vibration plate 10 is large, it is possible to drive for a long time.

[0015]

According to the ultrasonic spraying device of the present invention, the peeling strength of the vibration plate from the piezoelectric vibrator reaches about 10 times that of the conventional device, so that the durability of the device can be increased. Moreover, peeling between the piezoelectric vibrator and the vibration plate can be suppressed without hindering the atomization function. Therefore, the atomizing function can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an ultrasonic spraying device of the present invention.

FIG. 2 is a partial cross-sectional view showing a first embodiment of the system unit 1.

FIG. 3 is a partial cross-sectional view showing a second embodiment of the system unit 1.

FIG. 4 is a partial cross-sectional view showing a third embodiment of the system unit 1.

FIG. 5 is a sectional view showing an example of a conventional ultrasonic atomizing device.

6 is a cross-sectional view of the embodiment of FIG. 5 viewed from the diaphragm side.

[Explanation of symbols]

 1 System Unit 2 Spring 3 Nozzle 4 Liquid Absorbing Material 5 Storage Chamber 6 Housing 7 Cover 8 Battery 9 Piezoelectric Vibrator 10 Vibration Plate 11 Drive Circuit 12 Case 13 Piezoelectric Ceramic 14 Through Hole P, Q Electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Hashimoto 2480 Kuno, Odawara-shi, Kanagawa Mikuni Odawara factory (72) Inventor Koji Toda 1-49-18 Futaba, Yokosuka City, Kanagawa Prefecture

Claims (2)

[Claims] 1. An ultrasonic spraying device for atomizing a liquid from a vibrating plate by bringing a sponge, a fiber bundle or other hydrophilic liquid retaining material into contact with a perforated vibrating plate fixed to a piezoelectric vibrator. The child is composed of a substantially rectangular plate-shaped piezoelectric ceramic and electrodes P and Q fixed to the piezoelectric ceramic. The electrodes P are both end surfaces A perpendicular to the thickness direction of the piezoelectric ceramic.
And a part of the end surface A of B, and the electrode Q
Is provided from a part F of the surfaces adjacent to the end faces A and B of the piezoelectric ceramic to the end face B, the electrodes P and Q are in an insulated state from each other, and the diaphragm is the part F. It is fixed to the piezoelectric vibrator via the electrode Q on the end surface B near the boundary line with the end surface B, one is fixed to the portion F near the boundary line, and the other is fixed near the boundary line. An ultrasonic spraying device, wherein a reinforcing material fixed to the diaphragm is provided between the portion F and the diaphragm. 2. The piezoelectric ceramic has a structure in which a columnar structure having a height of one side out of 12 sides of the rectangular plate is cut off from the rectangular plate, and the end face B is The ultrasonic spraying device according to claim 1, wherein the piezoelectric ceramic is adjacent to the surface S of the portion where the columnar structure is cut off, and the surface S is included in the portion F.