JPH04118069A - Ultrasonic atomizer - Google Patents

Abstract

PURPOSE:To reduce the power loss in a vibration system and to facilitate the fabrication and assembly by providing a cylinder, a vibrator phone fixed in the cylinder, an electroacoustic transducer element for imparting ultrasonic vibration to the phone and an atomization part formed at the tip of the phone. CONSTITUTION:This ultrasonic atomizer is composed of a cylinder 2, a vibrator phone 3 fixed and supported in the cylinder 2, an electroacoustic transducer element 4 for imparting ultrasonic vibration to the phone 3 and a sleeve member 6 to be screwed on the cylinder 2 by the thread part 5. An annular liq. supply passage 7 is formed between the cylinder 2 and the sleeve member 6, and a liq. is supplied to the passage 7 from a liq. supply pipe 8 welded to the sleeve member 6. An atomization part 3a is formed at the tip of the phone 3. An annular nozzle 7a is formed between the cylinder 2 and the sleeve member 6, and the liq. is supplied to the atomization part 3a from the nozzle 7a and atomized by the ultrasonic vibration. Consequently, the power loss in the vibration system is reduced by half.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention generally relates to liquid substances such as liquid fuels (in this specification, liquid substances are not only liquids such as liquid fuels) but also liquid substances such as liquid fuels that are supplied. (Used to include liquid substances such as cloudy solutions.) Using ultrasonic vibration, it is used to atomize ultrasonic atomizers, particularly (a) automobiles, outboard motors, portable power devices, Ultrasonic atomizers applied to internal combustion engines used in the drive devices of consumer heat pump devices, etc.; (b) fuel injection nozzles for gas turbines; (c) boilers and heating furnaces for industrial, commercial and domestic use; Heating burners, (d) Industrial liquid sprayers, such as drying sprayers for drying liquid materials such as food, pharmaceuticals, agricultural chemicals, fertilizers, etc., temperature and humidity control sprays, baked powder sprayers (ceramic granulation) , a spray coating device, a reaction accelerator, and (e) an ultrasonic atomizer suitable for use in non-industrial liquid sprayers, such as pesticide sprayers, disinfectant sprayers, etc.

[Prior Art] Conventionally, as an ultrasonic atomization device that uses ultrasonic waves to atomize a liquid substance into extremely small droplet size, for example, Japanese Patent Application Laid-Open No. 1983-1999
As shown in Publication No. 13B2E32, a vibrator horn is disposed inside a cylinder, a sleeve member is disposed around the outer periphery of the cylinder, and the vibrator horn is connected to the annular liquid supply path formed between the cylinder and the sleeve member. A method is known in which the liquid is uniformly atomized by supplying liquid to the entire circumference of the atomizing surface at the tip.

Conventionally, in the above method, a fixing flange is formed integrally with the node portion of the vibrator horn, and the flange is fixed and supported on the cylinder.

[Problems to be Solved by the Invention] Theoretically, there is a point in the node portion of the vibration system of the vibrator horn that no power loss occurs even if it is fixed. However, in reality, because the fixing flange has a width rather than a point, and because the speed of sound differs even with the same material, the positions of the respective node parts are different even if the vibrator horn is manufactured with the same dimensions. It will be different. As a result, there is a problem in that vibration occurs in the flange portion, resulting in a corresponding power loss in the vibration system.

Further, there are problems in that the cutting process of the flange requires high precision, which increases the cost, and that the flange needs to be tightened uniformly, resulting in poor assembly performance.

Furthermore, in an atomizing device, the relative position of the liquid supply nozzle and the atomizing part at the tip of the vibrator horn is an important factor in the exposure characteristics, but in the case of fixation with a flange, the relative position is fixed. Therefore, there is a problem in that the degree of freedom in adjusting the atomization characteristics is restricted.

In order to solve these problems, the applicant has
No. 22694 discloses a cylinder, a vibrator horn fixed in the cylinder, an electric/acoustic transducer that imparts ultrasonic vibration to the vibrator horn, and an atomization formed at the tip of the vibrator horn. The present invention has proposed an ultrasonic atomizing device, which has a sleeve member for supplying liquid to the atomizing portion, and is characterized in that the vibrator horn is fixed by rubber members at both ends of the cylinder.

However, when the present inventor conducted various experiments,
It was found that dripping occurred at the atomizing section at the tip of the vibrator horn.

The present invention solves the above problems, and provides an ultrasonic atomization device that reduces power loss in the vibration system, is easy to manufacture and assemble, and can prevent liquid dripping. The purpose is to

[Means for solving the problem] For this purpose, the ultrasonic atomization device of the present invention includes a cylinder 2,
A vibrator horn 3 fixed in the cylinder, an electro-acoustic transducer 4 that imparts ultrasonic vibration to the vibrator horn, and a mist formed at the tip of the vibrator horn with a radius of curvature R. The atomizing section 3a and the sleeve member 6 that supplies liquid to the atomizing section are connected, and the vibrator horn 3 is connected to the cylinder 2.
is fixed by rubber members 12 and 13 at both ends thereof, and the radius of curvature is set to 3. 5mm±0. It is characterized by being set to 5 mm.

Note that the numbers added to the above configurations are for comparison with the drawings, and the configurations of the present invention are not limited thereby.

[Operation] In the present invention, since the vibrator horn is fixed and supported by rubber members at two locations on the cylinder, the vibrator horn is fixed to the cylinder with flexibility at a position that optimizes the atomization characteristics. It can be supported. Also, the radius of curvature of the atomizing part at the tip of the vibrator horn was set to 3.5 mm ± 0. By setting the optimum value of 5 mm, dripping can be prevented.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial cross-sectional view showing one embodiment of the ultrasonic atomization device of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG.

As shown in FIGS. 1 and 2, the ultrasonic atomizer 1 applies ultrasonic vibration to a cylinder 2, a vibrator horn 3 fixed and supported within the cylinder 2, and a vibrator bore 3. It is composed of an electric/acoustic transducer 4 and a sleeve member 6 that is screwed onto the outer periphery of the cylinder 2 at a threaded portion 5 . An annular liquid supply path 7 is provided between the cylinder 2 and the sleeve member 6.
A liquid supply pipe 8 is formed and fixed to the sleeve member 6 by welding.
A liquid is supplied from the liquid supply path 7 to the liquid supply path 7 .

An exposed portion 3 a is formed at the tip of the vibrator horn 3 . The shape of the atomizing portion 3a is such that a radius of curvature is formed at the tip of a mouth/throat shape. Further, an annular nozzle part 7a is formed between the cylinder 2 and the sleeve member 6, and liquid is supplied from the nozzle part 7a to the atomizing part 3a and atomized into fine droplets by ultrasonic vibration.

The vibrator horn 3 is fixed and supported at both ends of the cylinder 2 by oil-resistant rubber members 12 and 13.

When fixing, first place the vibrator horn 3 inside the cylinder 2.
is inserted and positioned using a jig or the like so that their concentricity is adjusted and the relative position of the atomizing part 3a and nozzle part 7a is in the optimum atomizing state, and then liquid rubber is injected into both ends. It is to be fixed in place.

Therefore, machining of the O-ring and the O-ring groove is not necessary, improving dimensional accuracy and reducing costs.

In addition, since the concentricity between the vibrator horn 3 and the cylinder 2 is ensured, the sleeve member 6 is fixed to the cylinder 2 only by the short threaded part 5, and unlike the conventional case, the sleeve member 6 is fixed to the cylinder 2 by the short threaded part 5. There is no need for a fitting part to ensure concentricity between the two, making it possible to shorten the overall length and increase rigidity.

Furthermore, thermal strain caused by welding when fixing the liquid supply pipe 8 to the sleeve member 6 can be reduced.

FIG. 3 shows a method of fixing between the atomizing section side end of the vibrator horn 3 and the cylinder 2 using a rubber member 12. (a) shows a method in which the tip of the cylinder 2 is thickened, and the inner periphery of the tip of the cylinder 2 and the cylinder 2 are thickened. The rubber member 12 is arranged in the thick part, and (b) shows an example in which the tip of the cylinder 2 has a sharp edge.

FIG. 4 shows a method of fixing the end of the vibrator horn 3 opposite to the atomizing part and the cylinder 2 with a rubber member 13.
(a) is an example in which the rear end of the cylinder 2 is cut at a right angle, (b) is an example in which a step is formed on the inner circumferential side of the rear end of the cylinder 2, and (C) is an example in which an inclined surface is formed on the inner circumferential side of the rear end of the cylinder 2. An example is shown below.

FIG. 5 shows a state in which the radius of curvature formed at the tip atomizing portion 3a of the vibrator horn 3 is changed, and the radius of curvature is set to R.
When increasing R2 from 1 to R2, the position of the atomizing part becomes farther from the nozzle part 7a from 3a+ to 3a2, so the nozzle part 7
The liquid supplied from a to the atomizing section drips due to gravity. Figure 6 shows the relationship between the radius of curvature R formed in the atomization part, the amount of liquid dripping, and the atomized particle size, and the radius of curvature is 41 mm.
It was found that when the radius of curvature is 1 mm or more, the amount of liquid dripping increases rapidly, and when the radius of curvature is 3 mm or less, the particle size increases rapidly.

Therefore, the radius of curvature of the tip atomizing section 3a is set to 3. 5a+m±
0. If it is set to 5 mm, dripping can be prevented.

FIG. 7 shows an example of the radius of curvature formed in the tip atomizing portion 3a of the vibrator horn 3. (a) As shown in the figure, the diameter of the vibrator horn 3 is 7 mm and the radius of curvature is 3. 5mm
In this case, the atomizing section 3a has a hemispherical shape. Also, (b
) As shown in the figure, if the diameter of the vibrator hole 73 is 10 mm and the radius of curvature is 3.5 mm, the atomizing part 3a has a diameter of 31 mm at the tip.
The shape has a flat portion 3b.

FIG. 8 shows another embodiment of the invention.

As a result of various experiments, in the above embodiment, the nozzle part 7
It has been found that because the tip of the sleeve member 6 constituting part a is sharp, the liquid supplied from the nozzle part 7a to the atomizing part 3a drips halfway due to gravity. Therefore, a thick tip portion 6a was formed at the tip of the sleeve member 6. FIG. 9 shows the experimental results of the thickness D of the thick tip portion 6a and the amount of dripping. According to this, it was found that if the tip thickness D is 1 mm or more, the amount of liquid dripping is almost negligible. This is because the liquid discharged from the nozzle portion 7a is held on the vibrator horn 3 side due to surface tension with the thick tip portion 6a.

[Effects of the Invention] As described above, according to the present invention, since the vibrator horn is fixed and supported by the rubber member at the 2yA position of the cylinder, the vibrator horn is fixed to the cylinder at a position that optimizes the atomization characteristics. Compared to the conventional case of rigidly fixing with a flange, the power loss of the vibration system can be reduced to about half, and the cutting and assembly of the vibrator horn can be easily performed.

Furthermore, since the radius of curvature formed in the atomization section is set to an optimal value, dripping is prevented.

Furthermore, since a thick part is formed at the tip of the sleeve member,
The liquid coming out of the nozzle part is held on the vibrator horn side by the surface tension with the thick tip part, thereby preventing the liquid from dripping.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one embodiment of the ultrasonic exposure apparatus of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG.
The figure is an enlarged cross-sectional view showing a method of fixing between the atomizing part side end of the vibrator horn and the 7th ring using a rubber member, and Figure 4 shows the rubber member fixed between the atomizing part side end of the vibrator horn and the cylinder. An enlarged sectional view showing a method of fixing with a member, FIG. 5 is an enlarged sectional view showing a state in which the radius of curvature formed at the atomizing part at the tip of the vibrator horn is changed, and FIG. Diagram showing the relationship between the radius of curvature, the amount of liquid dripping, and the atomized particle size, No. 7
The figure shows an example of the radius of curvature formed at the tip atomizing part of the vibrator horn, FIG. 8 is an enlarged sectional view showing another embodiment of the present invention, and FIG. 9 shows the thickness of the tip of the sleeve member and the liquid It is a figure which shows the experimental result of the amount of sagging. 1... Ultrasonic atomizer, 2... Ninda, 3...
Vibrator horn, 3a...Atomization part, 4...Electro-acoustic conversion element, 5...Threaded part, 6...Sleeve member, 6
a...Tip thickness part, 7...Liquid supply path, 7a...Nozzle part, 8...Liquid supply pipe, 12.13...Rubber member. Applicant: Tonen Co., Ltd. Patent Attorney Hiroki Shirai (7 others) Figure 2 Figure 5 Figure 6 Song $R (mm)

Claims (2)

[Claims] (1) A cylinder, a vibrator horn fixed in the cylinder, an electric/acoustic transducer that imparts ultrasonic vibration to the vibrator horn, and a tip of the vibrator horn formed with a radius of curvature. and a sleeve member for supplying liquid to the atomizing part, the vibrator horn is fixed by rubber members at both ends of the cylinder, and the radius of curvature is set to 3.5 mm. An ultrasonic atomization device characterized by being set to ±0.5mm. (2) The ultrasonic atomizer according to claim 1, wherein a thick portion is formed at the tip of the sleeve member, and the thickness is set to 1 mm or more.