JP2580041Y2 - Ultrasonic atomizer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic atomizer which can be used as a sprayer for various liquids, such as an inhaler for chemicals or the like, or a sprayer for fragrance.

[0002]

2. Description of the Related Art Conventionally, as an ultrasonic atomizing device for atomizing water or the like, a liquid-absorbing ultrasonic vibrator is used in which a piezoelectric element is inserted into a shaft having a through-hole for sucking up liquid and is fastened and integrated. A structure in which a perforated plate is provided on the atomizing end side of the vibrator has been disclosed by the present applicant in Japanese Utility Model Application Laid-Open No. 64-28980.

FIG. 6 shows an upper structural portion of an ultrasonic atomizing apparatus of this type in which a perforated or net-like thin plate is arranged on the atomizing end side of a liquid-absorbing ultrasonic vibrator. The piezoelectric element is a metal shaft that is integrated by tightening. The shaft 1 has a through hole 2 for sucking up liquid. A flat perforated or net-like thin plate 35 is provided so as to be in contact with the atomization end face, which is the upper end face of the flange portion 23 formed integrally with the upper portion of the shaft body 1.

In the ultrasonic atomizer shown in FIG. 6, when the input power to the liquid-absorbing ultrasonic vibrator is large and the hole diameter of the porous or net-like thin plate is large (for example, 50 μm to several tens)
0 μm), the liquid which has risen through the liquid suction through-hole 2 by the ultrasonic vibration is subjected to the ultrasonic vibration of the atomization end face of the flange portion 23 and the action of the porous or net-like thin plate 35 which comes into contact with the liquid or opposes with a small gap. And atomized particles are sprayed and released into the air as atomized particles substantially determined by the hole diameters of a large number of small through holes of the porous or net-like thin plate 35.

[0005]

When applied to a small inhaler or a fragrance sprayer using a battery as a power supply, the input power to the liquid-absorbing ultrasonic vibrator should be as small as possible. It is desirable that the particle size be small. However, when the hole diameter of the porous or net-like thin plate 35 is reduced in order to reduce the particle size of the generated atomized particles (for example, to reduce the particle size to about several μm), the liquid becomes porous or net-like thin plate 35. The resistance when passing through the small through-hole becomes large, and the liquid that has risen through the liquid suction through-hole 2 spills between the atomized end face of the flange portion 23 and the perforated or net-like thin plate 35. As a result, the flange 2
As shown in FIG. 6, the droplet K adheres to the periphery of 3 and the driving impedance of the liquid-absorbing ultrasonic vibrator as seen from the driving circuit for exciting the liquid-absorbing ultrasonic vibrator becomes large. Can not follow the increase of the impedance,
Atomization stops.

In order to solve this problem, it is conceivable to increase the rigidity (thickness) of the perforated or net-like thin plate 35 and press the perforated or net-like thin plate 35 against the atomization end face with a spring or the like. However, at present, the electroforming method is preferable to realize a porous or net-like thin plate with minute through holes. However, when the wall thickness is increased, the hole diameter varies, and the atomized particles having a uniform particle diameter are not obtained. Cannot be generated.
Further, even if a simple flat porous or net-like thin plate is pressed against the atomizing end face of the flange portion by a spring force, the gap between the opening edge of the liquid sucking through hole and the porous or net-like thin plate due to the bending of the porous or net-like thin plate. The gap becomes excessively large, causing a problem that hinders atomization.

In view of the above, an object of the present invention is to provide an ultrasonic atomizer capable of generating fine atomized particles and having a stable atomizing operation.

[0008]

In order to achieve the above-mentioned object, an ultrasonic atomizing apparatus according to the present invention is a liquid-absorbing type in which a piezoelectric element is inserted into a shaft having a through-hole for sucking up liquid, and is tightened and integrated. On the atomizing end face side of the ultrasonic vibrator, the porous or net-like thin plate having a large number of minute through holes is arranged, and the porous or mesh-like thin plate has a downwardly facing convex surface, and the convex surface It is configured to be in pressure contact with the opening edge of the liquid sucking through hole.

[0009]

In the ultrasonic atomizing apparatus of the present invention, since the porous or net-like thin plate has a downwardly facing convex surface, the porous or net-like thin plate is located at the opening edge of the liquid suction through-hole on the shaft body side. Can be reliably pressed against each other. Therefore, even when the hole diameter of the micro through hole of the porous or net-like thin plate is reduced to about several μm and the resistance when liquid (water, perfume, chemical liquid, etc.) passes through the micro through hole becomes large, the liquid is in the form of a shaft. The inconvenience of spilling between the upper end surface and the perforated or net-like thin plate does not occur. As a result, it is possible to avoid the instability of the atomization operation due to the droplets adhering to the upper end of the shaft.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the ultrasonic atomizing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the ultrasonic atomizer according to the present invention.
An example will be described. In this figure, a liquid-absorbing ultrasonic vibrator 2
0 is a metal shaft 1 having a liquid suction through hole 2 formed therein.
The disk-shaped piezoelectric elements 15A and 15B are inserted and fastened integrally. That is, a through hole 2 for sucking liquid is formed in the center of the metal shaft 1, and the metal shaft 1
The disk-shaped piezoelectric element 15
The disk-shaped convex portion 3 forming one of the tightening surfaces of A and 15B is integrally formed, and the male screw portion 4 is formed on the lower portion of the intermediate portion. The outer dimensions of the disk-shaped projection 3 are substantially the same as those obtained by integrating a flat washer and a nut. For such a shaft body 1, an electrode plate 14A, a disc-shaped piezoelectric element 15A having a through hole at the center, an electrode plate 14B, a disc-shaped piezoelectric element 15B having a through hole at the center, and an electrode plate 14
C, and insert nut 5 with washer into male screw 4
Screwed into the disk-shaped piezoelectric element 15
A and 15B are tightened and integrated with the shaft body 1. And
The lower part of the metal shaft 1 is a horn part 21 for liquid absorption, and the upper part is a horn part 22 for atomization. A flange part for increasing the amplitude of ultrasonic vibration is provided on the upper end part (upper part of the shaft body) of the horn part for atomization. 2
3 are integrally formed. Reference numeral 17 denotes a cylindrical insulating spacer provided on the outer periphery of the intermediate portion of the shaft body 1, and reference numeral 18 denotes an adhesive for preventing the nut 5 from loosening.

A waterproof case 6 is mounted on the above-described liquid-absorbing ultrasonic vibrator 20, and the liquid-absorbing ultrasonic vibrator 20 is fixed to a main body case (device housing) 40 by using the waterproof case 6. The supporting member 41 is attached to the main body case 40 side. The container 30 containing the liquid (water, perfume, chemical liquid, etc.) W is detachably attached to the lower part of the support member 41. A cylindrical portion 42 is formed integrally with the main body case 40, and a cylindrical spring support member 43 can be screwed into the cylindrical portion 42.

The porous or net-like thin plate 35A disposed on the upper end surface (atomization end surface) 31 of the flange portion 23 of the liquid-absorbing ultrasonic vibrator 20 has a generally curved downwardly convex surface. The outer edge is pushed down by a coiled compression spring 44. The upper portion of the coiled compression spring 44 is fixedly supported by screwing the cylindrical spring support member 43 to the main body case side cylindrical portion 42.

As shown in the enlarged sectional view of FIG. 2, the perforated or net-like thin plate 35A is a thin plate made of stainless steel or the like having a large number of minute through holes 36, and has a downwardly gently curved convex surface. (Ie, the angle θ in FIG. 2)
0), it is possible to reliably press the entire periphery of the opening edge 45 of the liquid suction through hole 2. The diameter of the small through hole 36 is 20 μm or less, and is set to several μm when particularly fine atomized particles are required. The flatness of the atomized end face 31 is finished to about ± 2 μm near the opening edge 45 of the liquid suction through-hole 2. ± 5 except for near the opening edge
A relatively coarse flatness of about μm may be used.

The liquid-absorbing ultrasonic vibrator 2 from the drive circuit
0 is supplied to the electrode plates 14A, 14A at both ends.
C may be electrically connected to each other (the piezoelectric elements 15A and 15B are electrically connected in parallel), and the lead wires 19 may be connected to the electrode plate 14C at one end and the intermediate electrode plate 14B, respectively.

In the configuration of the first embodiment shown in FIGS. 1 and 2, the liquid absorbing horn 21 of the liquid absorbing ultrasonic vibrator 20 is immersed in the liquid W in the container 30, and the disk-shaped piezoelectric elements 15A, 1
If the high frequency power from the drive circuit is applied to 5B and the ultrasonic vibration is performed, the liquid that has risen through the liquid suction through-hole 2 as indicated by the arrow Z1 by the ultrasonic vibration of the liquid suction horn portion 21 is used for atomization. The ultrasonic vibration of the atomizing end face 31 of the flange portion 23 on the upper part of the horn portion 22 and the action of the perforated or net-like thin plate 35A opposed thereto are atomized, and the holes of the many small through holes 36 of the perforated or net-like thin plate 35A. It is sprayed and released into the air as atomized particles whose size is almost determined. At this time, since the perforated or net-like thin plate 35A has a gently curved convex surface facing downward, the liquid sucking through hole 2 is formed.
Can be maintained in contact with the opening edge 45 of the small through hole 36.
Even if the hole diameter of is reduced to about 20 μm to several μm,
The phenomenon that the liquid spills to the side of the flange portion 23 through the atomized end face of the flange portion 23 and the porous or net-like thin plate 35A does not occur. For this reason, it is possible to prevent a situation in which droplets adhere to the flange portion 23 and the drive impedance of the liquid-absorbing ultrasonic transducer 20 as seen from the drive circuit suddenly increases, and atomization becomes unstable or atomization stops. And operation reliability can be ensured.

FIG. 3 shows a main configuration of a second embodiment of the present invention. In this figure, the porous or net-like thin plate 35B has a convex surface 50 facing only downward at the center and a flat surface 5 at the periphery.
It is 1. The structure in which the liquid-absorbing ultrasonic vibrator 20 and the perforated or net-like thin plate 35B are pushed down by a spring is the same as in the first embodiment. Even in this case, the convex surface 50 of the perforated or net-like thin plate 35B comes into pressure contact with the entire periphery of the opening edge 45 of the liquid suction through-hole 2 opened on the atomization end surface which is the upper end surface of the flange portion 23, and the first embodiment An effect equivalent to the example can be obtained.

It should be noted that the convex surfaces of the porous or net-like thin plates 35A and 35B shown in the first and second embodiments may be gently curved surfaces (including a curved flat plate), spherical surfaces, paraboloids, or the like. Good.

The atomizing end face, which is the upper end face of the flange portion 23 on the upper part of the shaft 1, may be a gentle concave face 55 as shown in FIG. 4 or a gentle convex face 56 as shown in FIG. You may. In short, it is sufficient that the convex surface of the porous or net-like thin plate can contact the entire periphery of the opening edge of the liquid suction through-hole 2 in a state where the porous or net-like thin plate having a downwardly facing convex surface is in contact with the atomization end face.

[0020]

As described above, according to the ultrasonic atomizing apparatus of the present invention, the porous or net-like thin plate has a downwardly-facing convex surface, and the convex surface of the liquid-absorbing ultrasonic vibrator is formed on the convex surface. The structure is such that the hole is pressed against the opening edge of the liquid suction through-hole formed in the body, so that even if the hole of the perforated or net-like plate is fine, the liquid flows from the upper end surface of the shaft to the space between the perforated or net-like thin plate. The phenomenon of dropping in the direction can be prevented. As a result, the instability of the atomization operation caused by the droplets adhering to the upper portion of the shaft body is removed, the stable atomization operation can be performed, and fine atomized particles can be generated.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a first embodiment of an ultrasonic atomizer according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the first embodiment.

FIG. 3 is a front sectional view showing a main part of a second embodiment of the present invention.

FIG. 4 is a front sectional view showing a modified example of the shape of the atomization end face, which is the upper end face of the flange portion.

FIG. 5 is a front view showing another modified example of the shape of the atomization end face which is the upper end face of the flange portion.

FIG. 6 is a front view of a main part for describing a problem of a conventional ultrasonic atomizing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft body 2 Through-hole for liquid suction 6 Waterproof case 14A, 14B, 14C Electrode plate 15A, 15B Disc-shaped piezoelectric element 20 Liquid-absorbing ultrasonic vibrator 23 Flange part 30 Container 35, 35A, 35B Porous or net-like thin plate 36 Micro through hole 44 Coiled compression spring 50 Convex surface

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B05B 17/06 B06B 1/06

Claims (3)

(57) [Scope of request for utility model registration] 1. A porous or net-like thin plate having a large number of minute through-holes on the atomization end face side of a liquid-absorbing ultrasonic vibrator in which a piezoelectric element is inserted into a shaft having a through-hole for sucking up liquid and fastened integrally. In the ultrasonic atomizer, the ultrasonic or porous thin plate has a downwardly facing convex surface, and the convex surface is in pressure contact with an opening edge of the liquid suction through-hole. Atomization equipment. 2. The ultrasonic atomizing apparatus according to claim 1, wherein a flange portion is integrally formed on an upper portion of said shaft body, and an upper end surface of said flange portion is said atomizing end surface. 3. The ultrasonic atomizer according to claim 1, wherein the diameter of the small through hole of the porous or net-like thin plate is 20 μm or less.