JPH0438460B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention generally relates to a technology for atomizing liquid substances using ultrasonic waves, and in particular to atomization and atomization of fuel for internal combustion engines such as diesel engines and gasoline engines, or external combustion engines such as boilers and burners. The present invention relates to an ultrasonic atomization device that can be suitably used for drying to produce powdered chemicals. As described above, the present invention is applicable to liquid substances (herein referred to as "liquid substances") in various applications.
Although it is applicable to the atomization of not only liquids such as liquid fuels, but also solutions or slurries such as liquids for pharmaceutical manufacturing, hereinafter, the present invention will mainly be applied to diesel engines and gasoline engines. The description will be made in connection with ultrasonic atomization and atomization of liquid fuel for internal combustion engines such as. BACKGROUND ART As is well known, this type of ultrasonic atomization device is driven by an ultrasonic vibration generating means consisting of a device such as an electric/acoustic transducer or a high frequency oscillator, and the ultrasonic vibration generating means. The device is equipped with an ultrasonic vibrator horn that atomizes the supplied liquid substance such as liquid fuel, but the size of the atomization flow rate and the size of the atomized droplets when atomizing the liquid substance are The quality of the atomization characteristics of the ultrasonic vibrator horn, such as the size of its diameter, causes various effects on the performance of a combustion device using the ultrasonic atomization device. For example, if the atomization characteristics of the ultrasonic vibrator horn are poor, the combustion device may not be able to properly control the air-fuel ratio, or the combustion condition may deteriorate, resulting in the reduction of hydrocarbons and carbon monoxide contained in the exhaust gas. Problems such as an increase in the amount of soot and an increase in the amount of soot will occur. In order to eliminate such problems in combustion devices, it is necessary to improve the atomization characteristics of the ultrasonic vibrator horn as described above. To date, many attempts have been made to apply ultrasonic vibrations to combustion devices to atomize the supplied liquid fuel in order to obtain favorable combustion conditions, thereby improving combustion efficiency. but,
Among the ultrasonic atomization devices that have been tried,
For example, all the fuel supplied to an internal combustion engine can be atomized and atomized by an ultrasonic atomizer of practical dimensions with good atomization efficiency without deteriorating the atomization characteristics, depending on the load or other needs. processing amount (e.g. approx.
10 c.c./sec). Until now, as a fuel atomization device using ultrasonic waves mainly aimed at application to internal combustion engines, there is, for example, Japanese Patent Application Laid-open No. 49-37017 to Kotteru. When applied to an internal combustion engine, the device disclosed in Kotteru's patent is capable of distributing the required fuel in a short time with a fine atomization particle size suitable for combustion in response to load fluctuations of the internal combustion engine. It is difficult to atomize effectively and efficiently in large quantities in a short amount of time. That is, it is difficult to obtain sufficient amplitude needed to atomize a large amount of liquid. This is because the device is a solid type and has a large mass, so if you try to secure a high amplitude, high stress will be generated and the material will not hold up. A further drawback is that the power consumption required to atomize the fuel supplied using this device is high. This is because the ultrasonic energy generated from the ultrasonic vibration generating means vibrates the ultrasonic vibrator horn, and the vibration of the ultrasonic vibrator horn causes the supplied fuel to be atomized at the atomization part of the ultrasonic vibrator horn. For atomizing fuel, a solid ultrasonic transducer horn with a large mass requires large ultrasonic energy to obtain a large amplitude, and therefore , a large amount of energy is required to atomize a large amount of fuel,
As a result, the stress applied to the horn becomes too high, making it difficult to atomize a large amount of fuel efficiently.
Furthermore, the ultrasonic energy (e.g., amplitude energy) that is transmitted to the atomizing portion of the ultrasonic vibration generating means or the solid ultrasonic transducer horn and used to atomize the supplied fuel is ultrasonic Because the vibrator horn is solid, the magnitude of the initial ultrasonic energy (for example, amplitude energy) given by the ultrasonic vibration generating means is approximately the same, unless attenuation due to mass is taken into account. However, it is difficult to say that this ultrasonic energy is being used effectively and effectively. This is because the amplitude energy required to atomize the supplied fuel in the atomization part of the ultrasonic vibrator horn is determined by the effective amplitude given to the fuel supplied to this atomization part. This is because the energy from the generating means cannot be said to be used effectively to increase the effective amplitude. (Here, the effective amplitude is the amplitude necessary for atomizing the liquid, and is the amplitude part in the direction perpendicular to the atomization surface where the liquid is supplied, and is expressed as absolute amplitude x sinθ. (where θ indicates the angle with respect to the central axis of the atomization surface). Therefore, it cannot be said that the ultrasonic energy from the ultrasonic vibration generating means is effectively and effectively atomizing the fuel into fine particle sizes, and the power consumption for atomizing the fuel is low. , as mentioned above, has the disadvantage of being large. Note that since the ultrasonic transducer horn is solid, it has a large mass, and the effect of attenuation of ultrasonic energy due to the mass cannot be ignored. Furthermore, since Kotteru's device uses a sleeve nozzle, when fuel is supplied, the fuel travels along the side wall of the ultrasonic vibrator horn and is supplied to the atomization part that atomizes the fuel below. The ultrasonic vibrator has a large contact area with the horn, and a large power loss occurs in this contact area. Furthermore, with Kotteru's equipment, a liquid pool grows on the outer circumferential surface of the lower end of the sleeve during operation, and this growing liquid pool falls, generating huge particle sizes and completely converting the large amount of fuel that is efficiently supplied into fine particles. It cannot be said that it is atomized by the diameter. In addition, when assembling the ultrasonic vibrator horn and sleeve in Kotteru's equipment, they tend to become eccentric, and once eccentric, the spray pattern that atomizes the fuel and flies in the surrounding direction becomes uneven, resulting in a uniform and desirable fuel. The disadvantage is that it is difficult to obtain the state. Therefore, the present invention was devised to improve the above-mentioned problems in conventional ultrasonic vibration atomizers such as Kotteru's device. An object of the present invention is to provide an ultrasonic atomizer capable of efficiently atomizing a large amount of liquid substance in a short period of time in response to load fluctuations. Another object of the present invention is to provide an ultrasonic atomization device capable of atomizing a liquid substance into atomized droplets of uniform and extremely fine particle size. Another object of the invention is to provide an ultrasonic atomization device that uses less power consumption when atomizing liquid substances. Another object of the present invention is to provide ultrasonic waves capable of efficiently supplying the liquid substance to the atomization part from at least one liquid substance supply mechanism when supplying the liquid substance to the atomization part of the ultrasonic atomization device. An object of the present invention is to provide an atomization device. Another object of the present invention is to change the affinity of the liquid substance applied to the atomization part of the ultrasonic atomization device with the surface of the atomization part, so as to atomize it into uniform and extremely fine droplets. An object of the present invention is to provide an ultrasonic atomization device that can further improve the atomization characteristics. Another object of the present invention is to provide an ultrasonic atomizer capable of atomizing a liquid substance even if the liquid substance is supplied to the atomizing part of an ultrasonic atomizer in an amount exceeding a set proper atomization amount. The objective is to provide a device for converting Another object of the present invention is to prevent turbulence from occurring in the liquid substance supplied to the atomization part by the combustion air flow flowing towards the atomization part of the ultrasonic atomization device to which the liquid substance is supplied. It is an object of the present invention to provide an ultrasonic atomization device that does not cause deterioration of atomization characteristics such as generation of large droplets due to adhesion of atomized droplets or adhesion of atomized droplets to each other. Another object of the present invention is to improve the resonance conditions of an ultrasonic atomizer by improving the cooling effect of the atomizing part of the ultrasonic atomizer to which a liquid substance is supplied. An object of the present invention is to provide an atomization device. Another object of the present invention is to provide an ultrasonic atomization device that is easy to assemble and easy to handle. SUMMARY OF THE INVENTION The above object is achieved by an ultrasonic atomization device according to the present invention. In summary, the present invention provides an ultrasonic vibration generator having an ultrasonic vibration generating means, one end side connected to the ultrasonic vibration generating means, and the other end side having an enlarged diameter part whose diameter increases toward the tip. In the ultrasonic atomization device, the ultrasonic atomizer includes a vibrator horn and exposes a liquid substance supplied to the enlarged diameter part from a liquid substance supply mechanism in the enlarged diameter part, in which a hollow part is formed in the enlarged diameter part from the tip side. and the hollow part is formed so that the cross-sectional area in each plane taken perpendicularly to the axial direction of the ultrasonic vibrator horn is approximately constant. It is. It has been found that by forming a substantially conical hollow portion in the enlarged diameter portion in this manner, the aforementioned problems occurring in conventional devices can be solved. In other words, compared to the conventional ultrasonic vibrator horn which has a large mass, in the ultrasonic atomizer of the present invention, the mass of the ultrasonic vibrator horn is smaller and it is also possible to generate flexural vibrations, which will be described in detail later. Therefore, unlike conventional devices, it is possible to finely atomize the liquid substance with the enlarged diameter portion of the ultrasonic vibrator horn even with small vibration energy. Here, the occurrence of flexural vibration in the ultrasonic transducer horn of the present invention is something that is not seen in conventional ultrasonic transducer horns, and the occurrence of this flexural vibration and the small mass of the ultrasonic transducer horn are This makes it possible for the ultrasonic atomizer of the present invention to atomize liquid substances more finely and in a larger amount than conventional ultrasonic atomizers. In other words, conventional devices such as Kotteru's device require a large amount of energy to atomize a liquid substance, but the ultrasonic atomization device of the present invention, which has a hollow section, can atomize a liquid substance using a small amount of energy. Energy can atomize the liquid substance and the applied vibrations can also be used very effectively at the atomization surface by generating flexural vibrations. As a result, when the dimensions of the atomization surface are the same and the same amplitude is to be obtained on the atomization surface, the ultrasonic transducer horn according to the present invention is better than the conventional one that does not form a hollow part. In other words, when the same power is supplied to the ultrasonic vibration generating means, the hollow part of the vibrator horn having the atomization surface of the same shape and size can be reduced. The ultrasonic transducer horn of the present invention, which is formed with The present inventors have discovered that it is possible to atomize in a large amount and in a large amount. Therefore, according to the ultrasonic atomization device of the present invention, a large amplitude can be easily obtained on the atomization surface compared to the conventional ultrasonic atomization device. Compared to conventional ultrasonic atomizers, it requires less power consumption to obtain the same amount of atomization.In other words, with the same power supply, the ultrasonic vibrator horn of the present invention consumes less power. However, compared to conventional ultrasonic transducer horns, it is possible to atomize a large amount of liquid substance, and the liquid substance can be atomized in smaller particle sizes. As a result, when the ultrasonic atomizer of the present invention is used as a fuel injection device for an internal combustion engine, it is possible to quickly respond to load fluctuations that require a large amount of fuel, and the atomized liquid has a fine particle size. The droplets make it possible to obtain favorable combustion conditions in the combustion chamber of an internal combustion engine. Furthermore, by forming the hollow portion so that the cross-sectional area in each of the planes is approximately constant, the stress applied to the atomization surface of the enlarged diameter portion of the ultrasonic atomization device according to the present invention is reduced, and further, By utilizing the aforementioned flexural vibration, the amplitude can be further reduced, and this, combined with the small mass of the ultrasonic vibrator horn, allows the ultrasonic atomization device of the present invention to produce a large amount of liquid material with a small application of energy. Unlike conventional devices that require a large stress burden, the enlarged diameter section of the ultrasonic atomization device according to the present invention requires a small stress burden and is therefore favorable in terms of material strength. . As a result, the ultrasonic transducer horn of the present invention can be selected from various materials including not only titanium, stainless steel, copper, aluminum and alloys thereof, but also ceramics and the like. In a preferred embodiment of the present invention, the cross-sectional area of the ultrasonic transducer horn in each plane must be approximately constant from the viewpoint of material strength, that is, to avoid stress concentration. However, even if this cross-sectional area varies within a range of ±40%, the above-described advantages of the present invention can be enjoyed. Further, the wall thickness of the enlarged diameter part formed by forming the hollow part is 20% or less of the tip radius of the enlarged diameter part at the tip of the enlarged diameter part, and thereby, Vibrations applied in the axial direction tend to cause radial vibrations, resulting in flexural vibrations. Formation of such a hollow portion is not seen in conventional devices. Further, the tip of the enlarged diameter portion is set to have the maximum amplitude, so that the applied vibration can be effectively used to effectively atomize the supplied liquid substance. I can do it. Furthermore, the outer peripheral surface shape of the enlarged diameter portion is formed to have a conical shape or a conically curved surface (laptop type) shape, thereby providing a substantial amount of atomization for atomizing the supplied liquid substance. Effective atomization area can be expanded. The apex angle of the hollow part is formed to be 0° to 30° larger than the apex angle of the enlarged diameter part, and thereby,
For example, the hollow portion can be easily formed into a conical shape. In the ultrasonic atomizer according to the present invention, the ultrasonic vibrator horn is set in a section extending from a small diameter portion formed in a small diameter to an end portion forming a large diameter portion formed in a large diameter. A roughened surface may be applied to a region from a part of the atomization region to the small diameter portion for atomizing the liquid substance contained in the ultrasonic transducer horn, thereby improving the surface roughness of the atomization surface of the ultrasonic transducer horn. This improves the affinity between the liquid substance and the supplied liquid substance, and makes the atomized particle size uniform and smaller. Further, a flange portion may be formed at an end portion of the ultrasonic transducer horn that is formed to have a large diameter and is a large diameter portion.
With this, it is possible to atomize the liquid substance over a wider range than the appropriate atomization amount of the ultrasonic atomization device without a collar, in other words, the limit atomization amount,
The amount of atomization can be increased. Furthermore, in the ultrasonic atomization device according to the present invention, a large diameter portion of the ultrasonic vibrator horn is provided on the outer circumferential portion adjacent to the end portion forming the large diameter portion formed to have a large diameter of the ultrasonic vibrator horn. A jet flow generator may be provided to generate a jet flow to weaken the air flow flowing toward the end of the diameter. As a result, the liquid substance supplied to the ultrasonic vibrator horn by the combustion air flow flowing toward the atomization surface of the ultrasonic vibrator horn from the outside is transferred to the downstream side of the atomization surface of the ultrasonic vibrator horn. It is possible to prevent deterioration of atomization characteristics such as generation of large droplets due to being washed away or the surface of the liquid adhering to the atomization surface being disturbed. Furthermore, the ultrasonic transducer horn is configured to introduce air that flows along a space formed by the ultrasonic transducer horn and a casing surrounding the ultrasonic transducer horn into the hollow part. can form a path. This makes it possible to suppress the generation of soot in the large diameter portion of the transducer horn and improve the cooling effect of the transducer horn.As a result, the difference in resonance conditions between the ultrasonic vibration generating means and the ultrasonic transducer horn can be reduced. can also be prevented. Further, in the ultrasonic atomization device of the present invention, the ultrasonic vibration generating means and the ultrasonic vibrator horn may be connected to each other so as to be able to come and go, and the ultrasonic vibration generating means and the ultrasonic vibrator horn may be connected to each other. The connection part with the ultrasonic vibrator horn, which is connected to the ultrasonic vibrator horn in a separable manner, can be set to be an antinode of vibration, and an Allen socket or a groove part is formed in the hollow part of the ultrasonic vibrator horn. can do. This makes it compact and easy to assemble, without adversely affecting the atomization properties of the ultrasonic atomization device, and therefore easy to handle. Further, in the ultrasonic atomizer of the present invention, a liquid substance supply mechanism including a spout nozzle that supplies liquid substance to an enlarged diameter part of the ultrasonic transducer horn is connected to a small diameter part of the ultrasonic transducer horn. It is arranged at a predetermined angle so as to supply the liquid substance to the boundary of the starting portion of the diameter portion or a position slightly above the boundary. As described above, the liquid substance supply mechanism equipped with the jet nozzle of the present invention can stabilize the spray pattern, unlike the conventional sleeve nozzle type fuel supply device in which fuel is transmitted along the side wall of the ultrasonic vibrator horn. Liquid substances can be stably supplied from low flow rates to large flow rates. In one embodiment of the present invention, in order to increase the effective atomization area, a plurality of predetermined angles of the liquid substance supplied from the liquid substance supply mechanism to the ultrasonic transducer horn may be set. However, for details, please refer to the Examples described below. Effect of the Invention In the ultrasonic atomization device of the present invention, the ultrasonic generating means is driven by the driving means, and by this driving, the ultrasonic generating means generates ultrasonic waves, and the generated ultrasonic waves are The ultrasonic waves are transmitted to an ultrasonic transducer horn having a hollow part connected to an ultrasonic generating means, and a deflection vibration is generated in the enlarged diameter part of the ultrasonic transducer horn, and at this time, the ultrasonic transducer is When the liquid substance supplied to the horn flows down to the enlarged diameter part and reaches the atomization area, it is caused by the ultrasonic vibrations transmitted to the ultrasonic transducer horn and the flexural vibrations generated in the enlarged diameter part of the ultrasonic transducer horn. The liquid substance in the atomization region is efficiently atomized to extremely fine particle size, and the atomized droplets of fine particle size fly from the enlarged diameter portion in the circumferential direction. EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an ultrasonic atomizer 20 according to a first embodiment of the invention. As mentioned above, the ultrasonic atomizer of the present invention can be used as a fuel atomizer for internal combustion engines such as diesel engines and gasoline engines, or external combustion engines such as boilers and burners, as well as other atomizers for various uses. An example is described below, which can be applied. As is already well known, the ultrasonic atomizer 20 includes an ultrasonic vibration generating means consisting of an electric/acoustic transducer and a high frequency oscillator that drives the electric/acoustic transducer, and an ultrasonic transducer horn 10 driven by the ultrasonic transducer horn 10; and a liquid supply for supplying a liquid substance such as liquid fuel to the ultrasonic transducer horn 10 and atomizing the liquid substance by the ultrasonic transducer horn 10. tube 2
2 and the liquid supply pipe 2;
The ultrasonic transducer horn 10 is provided with a casing 21 that encloses two liquid supply holes and also surrounds the ultrasonic transducer horn 10. Thus, in the ultrasonic atomization device of the present invention, the ultrasonic generating means is driven by the driving means (not shown), and by this driving, the ultrasonic generating means generates ultrasonic waves, and the generated ultrasonic waves are The ultrasonic waves are transmitted to the ultrasonic transducer horn connected to the ultrasonic generating means, and at this time, the liquid substance supplied from the liquid substance supply mechanism to the ultrasonic transducer horn flows down to the enlarged diameter part and is atomized. When the atomization zone is reached, the liquid substance in the atomization zone is atomized by the ultrasonic vibrations transmitted to the ultrasonic vibrator horn, and atomized droplets fly from the enlarged diameter section toward the circumference. To further explain the ultrasonic transducer horn 10, in FIG.
A small diameter portion is formed in a cylindrical shape along the axial direction of the vibrator horn 10 from the end (upper side in FIG. 1) of the side connected to the electric/acoustic conversion element constituting the ultrasonic vibration generating means. The end opposite to the electric/acoustic conversion element (lower side in Figure 1) is formed to have a large diameter, and the section from the small diameter part to the large diameter part has a substantially conical shape. It is formed in an enlarged diameter shape. This enlarged diameter shape may be formed to have a curved shape, that is, a so-called flared shape (in this case, it will be a truss shape). Stress is concentrated at the boundary between the outer circumferential surface of the enlarged diameter portion of the ultrasonic transducer horn 10 (hereinafter simply referred to as the "enlarged diameter section 1a") and the outer circumferential surface of the small diameter portion of the transducer horn 10. An rounded portion is provided to prevent this, and a supply axis of the liquid substance supplied from the liquid supply hole of the liquid supply pipe 22, which is the liquid substance supply mechanism described above, is preferably set at a predetermined position near this boundary. There is. This liquid substance supply mechanism will be described later. Further, the outer circumferential surface of the enlarged diameter portion 1a of the ultrasonic transducer horn 10 serves as an atomization portion, that is, an atomization surface 2, for atomizing the liquid substance supplied from the liquid supply hole of the liquid supply pipe 22. ing. Furthermore, in the present invention, as is clear with reference to FIG. 1, the small diameter of the ultrasonic transducer horn 10 is a hollow part 3 that reaches a part of the part and opens to the large diameter part;
is formed. The formation of the hollow portion 3 will be further described with reference to FIG. 2. In the ultrasonic atomization device of the present invention, the vibration at the end portion 3 of the ultrasonic vibrator horn 10 is made to have a maximum amplitude. Therefore, the hollow portion 3 is formed such that the end 3a (lower side in FIG. 1) of the vibrator horn 10 on the opposite side from the electric/acoustic conversion element is the antinode of vibration. At this time, the hollow portion 3 is perpendicular to the axis of the vibrator horn 10.
A donut-shaped cross-sectional area S formed between the inner circumferential surface 3c and the outer circumferential surface 3d of the hollow portion 3 by cutting along a plane _l1 that crosses Therefore, the hollow portion 3 is formed so that the amount decreases slightly or remains substantially constant from the end portion 3b to the end portion 3a. This cross-sectional area S is
As mentioned above, up to ±40% of a substantially constant value is allowed. A simple method for forming the hollow portion 3 to have the above-mentioned cross-sectional area S is as follows: That is, the outer peripheral surface 3d
The apex angle of the hollow portion ₃ formed along the inclination of the inner peripheral surface 3c toward the axis of the vibrator horn 10, that is, the apex angle of the inner peripheral surface 3c is taken as _θ2. In some cases, the hollow portion 3 may be formed in a conical shape or a conically curved surface shape (laptop shape) with the apex angle θ ₂ being 0° to 30°, preferably 5 to 10° larger than the apex angle θ ₁ . . Note that there is virtually no difference in the performance of the ultrasonic transducer horn of the present invention whether the enlarged diameter portion is conical or lattice shaped. The angle formed by the tangent at the center of the enlarged diameter section (the midpoint of the outer peripheral surface from the start of the enlarged diameter section to its tip) toward the axis of the vibrator horn is substituted for the apex angle. And this angle is the same as in the case of a conical horn.
Preferably, the angle is between 30° and 60°. Further, the wall thickness between the inner circumferential surface 3c and the outer circumferential surface 3d of the hollow portion 3, that is, the wall thickness of the enlarged diameter portion 1a, is set to 20% or less of the radius d at the end portion 3a of the enlarged diameter portion 1a. There is. That is, the thickness of this expanded diameter portion 1a formed by forming the hollow portion 3 is defined as the radius d.
The reason for setting it to 20% or less is to make it easier to generate vibrations in the radial direction, which will be described later. By forming the above-described hollow portion 3 from the large diameter portion to the small diameter portion of the ultrasonic transducer horn 10, the first As clearly understood from figure a, if the dimensions of the atomization surface 2 are the same and the same amplitude is to be obtained on the atomization surface 2, then
Ultrasonic transducer horn 10 according to an embodiment of the present invention
In other words, when the same power is supplied to the ultrasonic vibration generating means, the same shape can be obtained. , among the vibrator horns having atomization surfaces of the same size, the ultrasonic vibrator horn 10 with the hollow portion 3 formed therein atomizes the liquid substance on the atomization surface better than the ultrasonic vibrator horn without the hollow portion 3. The present inventors have found that a large amplitude can be obtained because of this. In FIG. 1a, as can be easily understood from the above description, curve A is the curve obtained by the ultrasonic atomizer of the present invention, and curve B is the curve obtained by the conventional ultrasonic atomizer. This is the curve obtained by This means that the ultrasonic transducer horn 10 of the present invention
According to When it comes to power supply, the ultrasonic transducer horn 10 of the present invention can atomize a larger amount of liquid substance than conventional ultrasonic transducer horns. Furthermore, the ultrasonic transducer horn 10 of the present invention can obtain a large amplitude necessary to effectively atomize liquid substances into fine particle sizes. Therefore,
On the atomization surface 2, as described above, a large amplitude can be easily obtained compared to the conventional one, so it is easy to atomize the liquid substance with a smaller particle size, and it is also easy to atomize a large amount. can do. Regarding the above, by forming the hollow part 3, the mass of the ultrasonic transducer horn 10 is reduced, and therefore the ultrasonic transducer horn 1
The vibration energy necessary to atomize the supplied liquid substance at the atomization surface 2 of 0, that is, the vibration energy to vibrate the ultrasonic vibrator horn 10 is:
Since the mass of the hollow part of the ultrasonic vibrator horn 10 is reduced, the vibration energy is reduced, and the atomization surface 2 has flexibility due to the thin wall thickness of the atomization surface 2. The end portion 3a of the ultrasonic vibrator horn 10 is set to be the antinode of the vibration so that the maximum amplitude can be obtained, and the vibration energy from the ultrasonic vibration generating means is directed in the axial direction of the ultrasonic vibrator horn 10. and is transmitted in the direction of the atomization surface (radial direction) having an inclination angle with respect to the axial direction,
As a result, a complex vibration occurs on the atomization surface 2 (hereinafter referred to as flexural vibration), and this flexural vibration easily causes a large amplitude on the atomization surface 2. Therefore, the large amplitude of this flexural vibration , acts effectively as the effective amplitude necessary to atomize the liquid substance, and acts very effectively to atomize the liquid substance supplied to the atomization surface 2 with a fine particle size, and also acts to generate a large amount of liquid. It also works effectively to easily atomize substances, resulting in less power consumption. In other words, if we consider the flexural vibration, the atomization surface 2
The effective amplitude required to finely atomize the liquid substance generated by Compared to ultrasonic atomizer,
Large quantities of liquid substances can be atomized to extremely fine particle sizes. Here, the effective amplitude necessary to atomize the liquid substance is not an absolute amplitude but an amplitude component in a direction perpendicular to the atomization surface, and this effective amplitude is expressed by absolute amplitude x sin θ. In other words, due to the flexural vibration, the effective amplitude generated on the atomizing surface increases, which effectively acts to atomize a large amount of liquid substance and finely, so that the same amount of liquid substance can be atomized. , the vertical vibration amplitude can be reduced, and as a result, the stress applied to the ultrasonic transducer horn can be reduced, and the range of selection is also limited from the viewpoint of material strength used for the ultrasonic transducer horn. spreads. Furthermore, since the donut-shaped cross-sectional area of the enlarged diameter part that becomes the atomization surface is formed to be almost constant at any position in the hollow part 3, stress concentration is not caused, and the material strength is improved. It is also preferable. For example, the materials that have been used for ultrasonic transducer horns,
It has been found that even if titanium is replaced with aluminum, sufficient durability can be obtained without impairing the atomization characteristics of the ultrasonic transducer horn configured according to the present invention. In addition, the enlarged diameter part 1 of the enlarged diameter ultrasonic transducer horn
When the apex angle of a is small, the effective amplitude required to atomize the liquid substance is not the absolute amplitude but the amplitude component in the direction perpendicular to the atomization surface, and this effective amplitude is expressed as: absolute amplitude x sin θ Therefore, in the past, a large amplitude was required from the ultrasonic vibration generating means to atomize a liquid substance, but in the ultrasonic atomizer of the present invention, a liquid substance is atomized due to flexural vibration. Therefore, even if the apex angle of the enlarged diameter portion 1a of the ultrasonic vibrator horn is small, the small amplitude from the ultrasonic vibration generating means can atomize the liquid substance. Now I can do it. Regarding this flexural vibration, please refer to Figure 3.
More specifically, FIG. 3 shows a part of the tip of the ultrasonic transducer horn 10 in an enlarged manner. is at position a, and when the ultrasonic transducer horn 10 is contracted, the tip of the ultrasonic transducer horn 10 is at position a', and when the ultrasonic transducer horn 10 is extended, The tip of the ultrasonic transducer horn 10 is located at
a″. Therefore, the ultrasonic transducer horn 1
The tip radius d of 0 is the ultrasonic transducer horn 10.
becomes larger when contracted, and the ultrasonic transducer horn 1
It becomes smaller when expanded to 0. As a result, in addition to the normal vertical vibration having an absolute amplitude applied from the ultrasonic vibration generating means to the atomization surface 2 of the ultrasonic vibrator horn 10, in the axial direction of the ultrasonic vibrator horn 10, On the other hand, radial vibrations are induced and added to the atomizing surface 2, so that the atomizing surface 2 performs a composite vibration that is a combination of these vibrations, that is, a flexural vibration. The generation of this flexural vibration at the atomization surface 2 increases the effective amplitude as described above, thereby increasing the atomization of the liquid substance supplied to the atomization surface 2 with a fine particle size and a large amount. This makes it easy to atomize. The average particle size and amount of atomized droplets obtained by the ultrasonic atomizer of the present invention are shown in order to compare them with those obtained by a conventional ultrasonic atomizer. The resulting figure is FIG. 3a, in which the vertical axis shows the average particle diameter and the horizontal axis shows the atomization amount, and the product of the present invention is shown by straight line A. The conventional one is shown by straight line B. This figure 3a
As is clear from the above, the ultrasonic atomization device according to the present invention has a smaller average particle size and a much larger amount of atomization than the conventional one. Here, in order to describe the effective amplitude at the atomization surface 2 of the ultrasonic atomizer of the present invention, a part of the tip of an example of the ultrasonic vibrator horn 10 of the present invention is shown in FIG. On the outer circumferential surface 3d of 1a, virtual point positions are set as P, O, N, M, L, K, J, I, H, G,
Think of it as F, E, D, C, B, A. Note that the effective amplitude is an amplitude component in a direction perpendicular to the atomization surface 2, and is expressed as the absolute amplitude of longitudinal vibration×sinθ. At this time, the outer peripheral surface 3d is the ultrasonic transducer horn 1.
For example, in this embodiment, the liquid substance supplied from the injection hole nozzle, which will be described later, is arranged at an angle of about 25 degrees with respect to the axial direction of the ultrasonic transducer horn 10. 15° to hit position H
Supplied with a 75° orifice nozzle inclination angle.
The effective amplitude of each point position in this manner is shown in Figure 5, where the vertical axis represents the amplitude and the horizontal axis represents the point position on the ultrasonic transducer horn. ) when the amplitude of the curve X representing the longitudinal amplitude is given to the ultrasonic transducer horn 10, it suddenly increases from the point position J and reaches the point position P at the tip.
Draw a curve Y where the amplitude is maximum. Note that the effective amplitude above the straight line Z that crosses the curve Y in the direction of the point position is the atomizable amplitude of the liquid substance, and the effective amplitude below it is the non-atomizable amplitude. As is clear from FIG. 5, in this case, atomization of the liquid substance begins approximately from point position L. Note that the generation of the deflection vibration on the atomization surface 2 described above has an extremely large effect. For example, in order to atomize the same amount of liquid substance, the ultrasonic atomizer of the present invention is more effective than a conventional ultrasonic atomizer that does not have a hollow part and therefore does not generate bending vibrations. The atomizing device is capable of atomizing with less vibration energy from the ultrasonic vibration generating means.
This means that less power is consumed; with the same power consumption, more liquid substances can be atomized compared to traditional ultrasonic atomizers. . Therefore, since the liquid substance can be atomized by supplying small amplitude vibration energy from the ultrasonic vibration generating means to the atomization surface 2, the stress load on the ultrasonic vibrator horn can be reduced. This also expands the selection of materials used for ultrasonic transducer horns from the viewpoint of material strength. In addition, the amplitude etc. from the ultrasonic vibration generation means,
When the same vibrational energy is applied to the atomization surface 2, the ultrasonic atomization device of the present invention generates flexural vibrations on the atomization surface 2, so that the supplied liquid substance has a larger effective amplitude, i.e. It is possible to atomize with greater vibrational energy and therefore with finer particle size. Here, we compared the vibration characteristics of an example A of the ultrasonic transducer horn of the present invention as shown in FIG. Table 1 shows the results.

[Table] As is clear from Table 1, when an input amplitude is given such that the longitudinal amplitude (half vibration) at the tip of the horn is 12.5 μm, in the case of conventional ultrasonic vibrator horn B, , its absolute amplitude remains 12.5 μm and there is no lateral (radial) amplitude, that is, substantially no flexural vibration occurs, whereas the ultrasonic transducer horn A of the present invention In this case, the absolute amplitude is 13.3 μm and the lateral amplitude is 4.6 μm, indicating that a considerable amount of flexural vibration occurs. Furthermore, regarding the longitudinal amplitude expansion factor, that is, the amplification factor of the longitudinal amplitude relative to the input amplitude, in the case of the conventional horn B, it is 2.69, whereas in the case of the horn A of the present invention, it is 9.19, and the It can be seen that it has become possible to obtain a large amplitude with great efficiency using the ultrasonic transducer horn. Furthermore, the maximum stress generated in the horn is 23.3Kg/mm ² in the case of the conventional horn B, while it is 6.88Kg/mm ² in the case of the horn A of the present invention, which is higher than that in the conventional horn. The maximum stress generated in the ultrasonic transducer horn of the present invention is much smaller than the maximum stress generated in the conventional ultrasonic transducer horn that does not form a hollow part, and the material strength is approximately 1/3. It can be seen that this is preferable from this point of view. In order to enlarge the atomization surface 2', which is the atomization area of the liquid substance, in the configuration shown in FIG. 1 described above, FIG.
This figure shows an ultrasonic transducer horn 10' that has been made thicker. By increasing the diameter upstream of the enlarged diameter portion in this way, the atomization area of the atomization surface 2' can be increased, and therefore, the atomization of the liquid substance can be further improved with fine particle size. It becomes possible to do it in large quantities. That is, by increasing the atomization area in this way, it is possible to reduce the amount of atomized liquid substance to be atomized per unit area of the atomization surface. Since the vibrational energy imparted to the liquid substance increases, it becomes possible to atomize a large amount of the supplied liquid substance with a smaller particle size. Next, the angle of the apex of the enlarged diameter portion of the ultrasonic atomizer according to the present invention shown in FIGS. 1 and 6 will be further described. When these ultrasonic atomizers described above are used as an atomizer in the intake pipe of an internal combustion engine such as a gasoline engine, care must be taken to prevent many atomized droplets from adhering to the wall of the narrow intake pipe. In other words, in order to prevent the atomized droplets from spreading in the circumferential direction at an excessively wide angle, the apex angle of the enlarged diameter portion needs to be set within a suitable range. However, when the apex angle of the enlarged diameter part is made small,
On the atomization surface, as is clear even when considering the mechanism of effective amplitude generation, it is extremely difficult to obtain a large amplitude necessary for atomization, and even if such a large amplitude is obtained, Even if this were possible, the stress applied to the enlarged diameter portion and the shaft portion would increase, causing problems in terms of material strength. Therefore, the diameter expansion of the ultrasonic atomizer of the present invention generates flexural vibrations and effectively utilizes the effective amplitude to atomize the supplied liquid substance to a finer particle size and in a larger amount. There is a preferred angular range for the apex angle of the part, as shown in Figure 7a, b and c, which is preferred according to the present invention to atomize the supplied liquid substance in a larger amount with finer particle size. In order to produce an effective amplitude of , the apex angle of the enlarged diameter section has yielded good results in the range of about 30° to 60°, preferably about 30° to 45°. As a result, a favorable atomization pattern is obtained, and no droplets are deposited in large quantities on the intake manifold wall, thus also impairing the responsiveness of the internal combustion engine to the supply of liquid substances and thus liquid fuel. There is no. Let me add further explanation to the above. In the ultrasonic transducer horn of the present invention, when the apex angle of the enlarged diameter portion is large, the effective amplitude for atomizing the liquid substance is large. Atomization is possible even if the liquid film formed on the surface is thick, and under conditions such as the same amplitude, the same atomization processing amount, and the same supply liquid velocity, ultrasonic waves with a large apex angle at the enlarged diameter part The vibrator horn is better
When a liquid substance arrives at the atomization surface, it immediately starts atomizing even if the liquid film is thick, and the atomized particle size becomes coarse. Since the effective amplitude of the atomization is small, the liquid film formed on the atomization surface must be thinner for atomization to occur, and the liquid film becomes thinner as it moves on the outer peripheral surface of the enlarged diameter part of the ultrasonic vibrator horn, resulting in atomization. begins and the particle size decreases. On the other hand, the effective atomization area becomes larger as the apex angle of the enlarged diameter portion is smaller, and the amount of atomized liquid substance to be supplied per unit area becomes smaller. This means that the liquid substance can be atomized even if the vibrational energy applied to the liquid substance to be atomized on the atomization surface is small. Therefore, when processing a large amount of liquid substance, it is preferable that the apex angle of the enlarged diameter portion be small from the viewpoint of effective atomization area. As mentioned above, in order to generate the flexural vibration of the present invention and effectively utilize the effective amplitude to atomize the supplied liquid substance with even finer particle size and a larger amount, it is necessary to expand the diameter. As mentioned above, the apex angle of the part is suitably in the range of about 30° to 60°, preferably about 30° to 45°. In the above embodiments, the shape of the outer peripheral surface of the enlarged diameter part of the ultrasonic transducer horn according to the present invention has been described as a conical shape. However, if the shape of the outer peripheral surface of the enlarged diameter part is a conical curved surface shape, that is, a truncated shape. The present invention can also be applied to As shown in Fig. 7d, such a conical curved surface shape, that is, a lattice-shaped enlarged diameter part is an enlarged diameter part in a section from a small diameter part formed with a small diameter to an end part formed with a large diameter. The outer peripheral surface is set so as to exhibit a curve when cut along the axis of the enlarged diameter portion. In this case, the angle formed by the tangent at the center of the outer peripheral surface of the enlarged diameter portion toward the axis of the ultrasonic transducer horn, that is, the apex angle of the enlarged diameter portion is approximately It has been found that a range of 30 to 60° is preferred. Next, a liquid substance supply mechanism for supplying liquid substance from the liquid substance supply mechanism to the ultrasonic transducer horn will be described. 8a, b, and c show a liquid substance supply mechanism for supplying liquid substance to the ultrasonic transducer horn 10 of the present invention. This liquid substance supply mechanism is normally provided around the outer periphery of the ultrasonic transducer horn 10 slightly obliquely above the outer periphery of the small diameter portion of the ultrasonic transducer horn near the boundary between the small diameter portion and the starting portion of the enlarged diameter portion 1a. At least one spout nozzle 5 is also arranged slightly apart from the surface (in this example, eight spout nozzles are arranged).
It is equipped with As shown in FIG. 8c, the position on the ultrasonic vibrator horn that supplies the liquid substance from the injection hole nozzle 5 of the liquid substance supply mechanism to the ultrasonic vibrator horn 10 is generally The diameter of the small diameter part of the ultrasonic transducer horn 10 is U, and the border position between the small diameter part and the enlarged diameter part 1a of the ultrasonic transducer horn 10, that is, the starting part of the enlarged diameter part 1a, and from this starting part It is preferable that V/U is within the range of 0 to 1, where V is the distance between the liquid substance supply point and the liquid substance supply point supplied from the upper liquid substance supply mechanism. When V/U is 0, it means that V=0, that is, the liquid substance supply position is located at the beginning of the enlarged diameter portion 1a. Note that depending on the supply speed of the liquid substance, the type of liquid substance, viscosity, and surface tension, the liquid substance can also be supplied below the boundary position, that is, to the enlarged diameter portion. Within this range, when the liquid substance is caused to flow down to the enlarged diameter portion 1a through the peripheral wall of the ultrasonic vibrator horn for atomization, it can be caused to flow down in a liquid film state. , the ultrasonic transducer horn 10 according to the present invention works satisfactorily to atomize liquid substances without any hindrance, since a uniform thin film favorable for atomization can be formed on the atomization surface. be able to. On the other hand, when the liquid substance is directly supplied to the enlarged diameter part 1a from the liquid substance supply mechanism, a uniform thin film is formed on the atomization surface because the enlarged diameter part 1a, which becomes the atomization surface, vibrates. Moreover, the liquid droplets may be splashed off the atomization surface without being atomized. Therefore, the spout nozzle 5 constituting the liquid substance supply mechanism is located at a boundary or above the boundary between the small diameter part and the starting part of the enlarged diameter part of the ultrasonic transducer horn (however, V/U=0 to 1). It suffices if they are arranged at a predetermined angle so as to supply the liquid substance to a range of . The liquid substance supply angle _{θ a} for supplying the liquid substance from the spout nozzle 5 of the liquid substance supply mechanism to the outer peripheral surface of the ultrasonic transducer horn 10 is as follows:
As shown in Figure 8c, a range of 15° to 75° is preferred. This range depends on the size of the injection hole nozzle 5 that supplies fuel, the supply speed of the liquid substance, the type of liquid substance,
Although it differs slightly depending on viscosity and surface tension, the present inventors have conducted research on gasoline, kerosene, diesel oil, slurry, etc., and have confirmed that they give good results. If this liquid substance supply angle θ _a is too small, the spread width 8a of the liquid substance will be small, and the liquid substance will be sufficiently spread over the atomization surface 2, and the atomization surface 2 will not be affected by the atomization action.
In order to effectively use the injection hole nozzle 5, the number of injection hole nozzles 5 must be increased, and in this case, the speed of the supplied liquid substance is not slowed down at the enlarged diameter part, and the supplied liquid substance is Problems arise during atomization, such as an adverse effect on the atomization section. Furthermore, if the liquid material supply angle θ _a is too large, when the speed of the supplied liquid material increases, the splashing of the liquid material or the swell 8b of the liquid material becomes large, and in the case of a horizontal position, the liquid drips. There is a possibility that this may occur. By using the spout nozzle 5 in this liquid substance supply mechanism, the spray pattern can be stabilized, and the liquid substance can be stably supplied from a low flow rate to a large flow rate. Another embodiment of the ultrasonic atomization device of the present invention as described above will be described. Another example is an ultrasonic transducer horn shown in FIG. This atomizes the liquid substance that is set in the section from the small diameter portion of the ultrasonic transducer horn 10 of the present invention to the end portion that is the large diameter portion. In the area from a part of the atomization area to the small diameter part,
For example, the surface is roughened by sandblasting. Such surface roughening in this region allows the liquid substance supplied from the liquid substance supply mechanism to the atomization surface of the ultrasonic transducer horn 10 to be mixed with the metal surface constituting the atomization surface of the transducer horn. Based on the relationship between the affinity and the atomization characteristics of the ultrasonic vibrator horn, the atomized particle size is made uniform from the small flow rate range to the medium flow rate range, as shown in Figure 10. Moreover, it can be made even smaller, and the atomization characteristics can be further improved. In addition, the 10th
The figure shows the average particle diameter on the vertical axis and the atomization amount on the horizontal axis, where curve This is based on the ultrasonic atomization device of the present invention in which the following steps were performed. In this case, sandblasting is performed using sand or metal particles (mesh 60
#) with an air gun for several seconds to several minutes to roughen the surface, observe it with an optical microscope (reflection type), and measure it with a roughness meter.
B0601) had a Ba value in the range of 2 to 6 μm. FIG. 11 shows an ultrasonic transducer horn according to yet another embodiment. As shown in FIG. 11, this ultrasonic atomization device has a large diameter portion (for example, 32 mm in diameter) formed in the large diameter of the ultrasonic vibrator horn 10.
A flange portion 11 having an inclination angle θ ₂ (angle between the flange portion and the axis of the ultrasonic transducer horn) of θ 2 =80°, for example, is formed at the end portion where θ ₂ =80°. Incidentally, the inclination angle θ ₁ of the atomization surface which is the enlarged diameter part (the angle between the enlarged diameter part and the axis of the ultrasonic transducer horn) is, for example, θ ₁ = 30°.
is the angle of As a result, the vertical axis shows the average particle size,
As shown in Fig. 12, in which the amount of atomization is plotted on the horizontal axis, in the case of no collar, the range of the limit atomization amount for atomizing the liquid substance on the atomization surface is shown by 12b. On the other hand, when a flange is formed, it is possible to atomize a wide range of the atomization range 12a that exceeds the range 12b of the limit atomization amount, and the amount of atomization can be further increased. And in this case, θ ₁ and θ ₂
As exemplified above, it is necessary that the relationship θ ₂ >θ ₁ be maintained between them. FIG. 13 shows an ultrasonic transducer horn according to still another embodiment. As shown in FIG. 13, this ultrasonic atomization device has a large-diameter end portion formed with a large diameter of the ultrasonic vibrator horn, and the ultrasonic wave A jet flow generating section 13a is provided that generates a jet flow for weakening the air flow flowing toward the large-diameter end of the vibrator horn. This causes the droplets supplied to the ultrasonic vibrator horn to flow downstream from the atomization surface of the ultrasonic vibrator horn due to the combustion air flow flowing from the outside toward the atomization surface of the ultrasonic vibrator horn. It is possible to prevent deterioration of the atomization characteristics, such as generation of large droplets due to the liquid surface adhering to the atomization surface being disturbed. FIG. 14 shows a part of an ultrasonic atomization device of still another embodiment. As shown in FIG. 14, this ultrasonic atomizer uses ultrasonic waves to generate air flowing along a gap formed by an ultrasonic transducer horn and a casing surrounding the ultrasonic transducer horn. An air introduction path 14a leading to a hollow portion formed in the vibrator horn is formed. This makes it possible to suppress the generation of soot in the hollow part of the transducer horn and improve the cooling effect of the transducer horn, thereby reducing the difference in resonance conditions between the ultrasonic vibration generating means and the ultrasonic transducer horn. can also be prevented. FIG. 15 shows an ultrasonic atomization device according to yet another embodiment. As shown in FIG. 15, this ultrasonic atomization device includes an ultrasonic vibration generating means 30a and an ultrasonic vibrator horn 10 connected to the ultrasonic vibration generating means 30a so as to be able to move toward and away from the ultrasonic vibration generating means 30a.
The connecting portion 31a with the ultrasonic vibrator horn is set to be the antinode of vibration, and an Allen socket 32a or groove portion is formed in the hollow portion 3 of the ultrasonic vibrator horn. This makes it compact and easy to assemble, without adversely affecting the atomization properties of the ultrasonic atomization device, and therefore easy to handle. FIG. 16 shows a part of an ultrasonic atomizer according to still another embodiment. Figures 16, 17 and 18
As shown in the figure, in this ultrasonic atomization device, a liquid substance supply mechanism 17a that supplies liquid substance to the enlarged diameter portion 1a of the ultrasonic transducer horn 10 is located near the outer peripheral portion of the ultrasonic transducer horn 10. (see FIG. 17), and the supply axes of the liquid substance supplied from each of the liquid substance supply mechanisms toward the ultrasonic transducer horn 10, in this embodiment, Ax and Ax, respectively. In this embodiment, a plurality of angles θx and θy are set between Ay and the axis of the ultrasonic transducer horn 10, respectively. Here, when the large diameter portion formed in the large diameter of the ultrasonic transducer horn 10 is, for example, 32 mm in diameter, the angle θx and the angle θy are each, for example, 40°.
and 20°. As a result, the atomization possible regions B ₁ and B ₂ of the liquid substance supplied from the liquid substance supply mechanism to the outer circumferential surface of the enlarged diameter part of the ultrasonic transducer horn become multistage (first
(See Figure 8), therefore, it is possible to set a large proportion of the atomization possible area on the outer peripheral surface of the enlarged diameter part of the enlarged diameter ultrasonic transducer horn, and further refine the atomized particle size. At the same time, by further increasing the amount of atomization, it is possible to further improve the atomization characteristics. In the other embodiments described above, the enlarged diameter portion of the ultrasonic transducer horn has been described as having a truss shape as shown in the drawings, but this enlarged diameter portion may also have a conical shape as described above. Of course. Furthermore, FIG. 19 shows the combustion characteristics of the ultrasonic atomizer of the present invention when it is applied to a boiler, as an example. In FIG. 19, the vertical axis is the smoke scale number (this is measured by a smoke tester made by Baccaratusha Co., Ltd. in the United States), and the horizontal axis is the oxygen concentration. Comparison results are shown between the combustion characteristics of the ultrasonic spray produced by the oxidizer and those of the pressure spray produced by a conventional pressure injection valve.
Here, the smoke scale number is a value that is measured by extracting and measuring a certain amount of soot and dust from exhaust gas, and changes in response to changes in the amount of soot and dust.It is a standard measurement of soot and dust concentration according to the American standard ASTM Da15665. It is based on the law. The combustion characteristics shown in Fig. 19 are obtained by using kerosene as the fuel, setting the end inclination angle of the ultrasonic vibrator horn to 25°, the diameter of the small diameter part to 11 mm, and the diameter of the large diameter part to 24 mm. Combustion characteristics of ultrasonic spray obtained when the ultrasonic vibrator horn of the present invention is applied to a boiler (lines represented by U and V in FIG. 19) and pressure spray produced by a conventional pressure injection valve This shows the results of comparing the combustion characteristics (the line indicated by W in Fig. 19).
As shown in the figure, it is clear that the ultrasonic spray produced by the vibrator horn has superior combustion characteristics, and can be applied to a wide range of combustion equipment such as oil heaters and boilers. Note that the application of the present invention is not limited to the embodiments described above, but is applicable to (a) automotive fuel injection devices, such as electronically controlled gasoline injection valves or electronically controlled diesel injection valves; (b)
Fuel nozzles for gas turbines, (c) Burners for industrial, commercial and domestic boilers, heating furnaces, and space heaters, (d)
Industrial liquid sprayers, such as food, medicine, pesticides,
Drying sprayers for the purpose of drying liquid materials such as fertilizers, temperature control and humidity control sprays, baked powder sprayers (Salamitsuku granulation), spray coating equipment, reaction accelerators, and
(e) non-industrial liquid sprayers, such as pesticide applicators;
It can be suitably used as a disinfectant sprayer, etc. In other words, it can be used in various ultrasonic atomization devices that atomize liquid substances using ultrasonic vibrations. The present invention has been described above in some detail with respect to its most preferred embodiment, but it goes without saying that the preferred embodiment can be modified in various ways without departing from the spirit and scope of this invention. Therefore, the present invention is not limited to the above embodiments in any way. Effects of the Invention As explained above, according to the ultrasonic atomization device of the present invention, it is possible to efficiently atomize a large amount of liquid substance in a short time compared to conventional devices. In this case, the atomized droplets have extremely fine particle size and are uniform. Furthermore, the power consumption required to atomize the liquid substance is low, and the liquid substance can be efficiently supplied from the liquid substance supply mechanism to the atomization part. can also be easily controlled. Moreover, the stress generated in the atomization portion can be made uniform, and an ultrasonic atomization device that is preferable in terms of material strength can be obtained. Further, according to the ultrasonic atomization device of the present invention, finer and more uniform atomized droplets can be obtained by changing the affinity between the liquid substance and the surface of the atomization portion. By forming the atomizer, it is possible to atomize the liquid substance in an amount exceeding the atomization limit, and furthermore, by providing a jet flow generating section, disturbance of the supplied liquid substance can be prevented. Further, by providing an air introduction path guided to the hollow portion, it is possible to suppress the generation of soot and improve the cooling effect of the vibrator horn. Furthermore, by making the ultrasonic vibration generating means and the ultrasonic vibrator horn moveable toward and away from each other, it can be easily assembled and handled.

[Brief explanation of drawings]

FIG. 1 is a partially sectional explanatory diagram of an ultrasonic atomizer according to a first embodiment of the present invention. FIG. 1a is a diagram showing the relationship between amplitude and input. FIG. 2 is a partially enlarged view of FIG. 1. FIG. 3 is an explanatory diagram for explaining the flexural vibration of the present invention. FIG. 3a is a diagram showing the relationship between average particle diameter and atomization amount. FIG. 4 is a partial side view showing a part of the tip of the ultrasonic transducer horn of the present invention. FIG. 5 is a diagram showing the relationship between the position of each point shown in FIG. 4 and the amplitude. FIG. 6 is a schematic explanatory diagram of an ultrasonic transducer according to another embodiment of the present invention. FIGS. 7a, b, c, and d are partial views showing various apex angles of the enlarged diameter portion of the ultrasonic transducer horn of the present invention. 8a, b, and c are partial explanatory views showing a liquid substance supply mechanism for supplying liquid substance to the ultrasonic transducer horn of the present invention. FIG. 9 is a front view of an ultrasonic transducer horn according to another embodiment of the present invention. FIG. 10 is a diagram showing the relationship between the average particle diameter and the amount of atomization when the ultrasonic transducer horn of the present invention is roughened.
FIG. 11 is a front view of an ultrasonic transducer horn according to another embodiment of the present invention. FIG. 12 is a diagram showing the relationship between the average particle diameter and the amount of atomization when a collar is attached to the ultrasonic vibrator horn of the present invention. Figure 13 shows
FIG. 7 is a front view of an ultrasonic transducer horn according to another embodiment of the present invention. FIG. 14 is a partial front view of an ultrasonic transducer horn according to another embodiment of the present invention.
FIG. 15 is a front view of an ultrasonic atomizer having an ultrasonic transducer horn according to another embodiment of the present invention. FIG. 16 is a partial front view of an ultrasonic atomizer according to another embodiment of the present invention. FIG. 17 is a diagram showing a liquid substance supply mechanism used in the ultrasonic atomization device shown in FIG. 16. FIG. 18 is a diagram showing an atomization pattern obtained when a liquid substance is supplied to the ultrasonic atomization device shown in FIG. 16 using the liquid substance supply mechanism shown in FIG. 17. FIG. 19 is a diagram showing a comparison result between the combustion characteristics of the ultrasonic atomizer of the present invention and the combustion characteristics of a conventional pressure injection valve. 1a... Expanded diameter part, 2... Atomization surface, 3... Hollow part, 3a... End part, 3b... Termination part, 3c... Inner peripheral surface, 3d... Outer peripheral surface, 5... Spout nozzle , 10
... Ultrasonic vibrator horn, 20 ... Ultrasonic atomizer, 21 ... Casing, 22 ... Liquid supply pipe, d
...Radius, S...Cross-sectional area, U...Small diameter diameter, V
...distance, θ ₁ , θ ₂ ... vertical angle, θ ... liquid substance supply angle, l ₁ ... plane.

Claims (1)

[Scope of Claims] 1. An ultrasonic vibration generating means, one end of which is connected to the ultrasonic vibration generating means, and the other end of which has an enlarged diameter portion whose diameter increases toward the tip. an ultrasonic atomizer comprising a vibrator horn and atomizing a liquid substance supplied to the enlarged diameter part from a liquid substance supply mechanism in the enlarged diameter part, wherein a hollow part is formed in the enlarged diameter part from the tip side. However, this hollow part is formed between the inner circumferential surface and the outer circumferential surface of the hollow part in each plane taken perpendicularly to the axial direction of the ultrasonic transducer horn. An ultrasonic atomizer characterized in that the cross-sectional area of an internal donut shape is formed to be approximately constant. 2. A patent characterized in that the wall thickness of the enlarged diameter part formed by forming the hollow part is 20% or less of the tip radius of the enlarged diameter part at the tip of the enlarged diameter part. An ultrasonic atomization device according to claim 1. 3. The ultrasonic atomization device according to claim 1 or 2, wherein the tip of the enlarged diameter portion is set to have a maximum amplitude. 4. The ultrasonic atomization device according to any one of claims 1 to 3, wherein the outer peripheral surface shape of the expanded diameter portion is approximately conical. 5. The ultrasonic atomization device according to any one of claims 1 to 3, wherein the outer peripheral surface shape of the enlarged diameter portion is a conically curved surface shape (a truss shape). 6 The apex angle of the expanded diameter portion is 30 to 60°, and the apex angle of the hollow portion is 0° to 30° less than the apex angle of the expanded diameter portion.
Claims 1 to 2 are characterized in that they are large.
The ultrasonic atomization device according to any one of Item 5. 7 Atomization for atomizing the liquid substance set in the section from the small diameter part formed in the small diameter part of the ultrasonic transducer horn to the end part which becomes the large diameter part formed in the large diameter part. The ultrasonic atomization device according to any one of claims 1 to 6, characterized in that a region from a part of the area to the small diameter part is roughened. 8. Any one of claims 1 to 7, characterized in that a flange portion is formed at the end portion of the ultrasonic transducer horn that is formed to have a large diameter and becomes a large diameter portion. The ultrasonic atomization device described in . 9 Adjacent to the end portion of the ultrasonic transducer horn that is formed to have a large diameter and become the large diameter portion, on the outer periphery thereof,
Claims 1 to 8 are characterized in that a jet flow generating section is provided that generates a jet flow for weakening the air flow flowing toward the large-diameter end of the ultrasonic transducer horn. The ultrasonic atomization device according to any one of the paragraphs. 10 The ultrasonic transducer horn is an air introduction path that guides air flowing along the inner part formed by the ultrasonic transducer horn and a casing surrounding the ultrasonic transducer horn to the hollow part. Claims 1 to 3 are characterized in that:
The ultrasonic atomization device according to any one of Item 9. 11. The ultrasonic atomization device according to any one of claims 1 to 10, wherein the ultrasonic vibration generating means and the ultrasonic vibrator horn are connected so as to be able to come into contact with and separate from them. 12. Claims characterized in that a connecting portion between the ultrasonic vibration generating means and the ultrasonic vibrator horn connected to the ultrasonic vibrator horn so as to be able to freely approach and separate from the ultrasonic vibration generating means is set to be an antinode of vibration. The ultrasonic atomization device according to item 11. 13. The ultrasonic atomization according to claim 11 or 12, wherein a groove for an assembly jig such as an Allen socket is formed in the hollow part of the ultrasonic vibrator horn. Device. 14. The liquid substance supply mechanism, which includes a spout nozzle that supplies liquid substance to the enlarged diameter part, supplies liquid at a boundary between the small diameter part of the ultrasonic transducer horn and a starting part of the enlarged diameter part, or at a position above the boundary. The ultrasonic atomization device according to claim 1, wherein the ultrasonic atomization device is arranged at a predetermined angle so as to supply the substance. 15 The boundary or the position above the boundary between the small diameter part of the ultrasonic transducer horn to which the liquid substance is supplied and the starting part of the enlarged diameter part is defined by the diameter of the small diameter part of the ultrasonic transducer horn 10 being U, and the diameter of the small diameter part of the ultrasonic transducer horn 10 being U. When the distance between the starting part of 1a and the liquid substance supply point from the liquid substance supply mechanism located above this starting part is V, V/U is within the range of 0 to 1. The ultrasonic atomization device according to claim 14. 16. The ultrasonic atomization device according to claim 14 or 15, wherein the predetermined angle is 15° to 75°. 17. The ultrasonic atomization device according to claim 1, wherein a plurality of predetermined angles of the liquid substance supplied from the liquid substance supply mechanism to the ultrasonic transducer horn are set. . 18 A patent characterized in that the wall thickness of the enlarged diameter part formed by forming the hollow part is 20% or less of the tip radius of the enlarged diameter part at the tip of the enlarged diameter part. Claims 14 to 17
The ultrasonic atomization device according to any one of the paragraphs. 19. The ultrasonic atomization device according to any one of claims 14 to 18, wherein the tip of the enlarged diameter portion is set to have a maximum amplitude. 20. The ultrasonic atomization device according to any one of claims 14 to 19, wherein the outer peripheral surface shape of the enlarged diameter portion is approximately conical. 21. Claims 14 to 21, wherein the outer peripheral surface shape of the enlarged diameter portion is a conically curved surface shape (laptop shape).
The ultrasonic atomization device according to any one of Item 19. 22 The apex angle of the expanded diameter portion is 30 to 60°, and the apex angle of the hollow portion is 0° to 30° less than the apex angle of the expanded diameter portion.
The ultrasonic atomization device according to any one of claims 14 to 21, which is large. 23 Atomization for atomizing the liquid substance, which is set in the section from the small diameter part formed in the small diameter part of the ultrasonic transducer horn to the end part which becomes the large diameter part formed in the large diameter part. The ultrasonic atomizer according to any one of claims 14 to 22, characterized in that a region from a part of the area to the small diameter part is roughened. 24. Any one of claims 14 to 23, characterized in that a flange portion is formed at the end of the large diameter portion of the ultrasonic transducer horn. The ultrasonic atomization device described in . 25 Air flow flowing toward the large-diameter end of the ultrasonic transducer horn adjacent to and on the outer periphery of the large-diameter end formed in the large-diameter portion of the ultrasonic transducer horn. The ultrasonic atomization device according to any one of claims 14 to 24, further comprising a jet flow generator that generates a jet flow for weakening. 26 The ultrasonic transducer horn is an air introduction path that guides air flowing along the inner part formed by the ultrasonic transducer horn and a casing surrounding the ultrasonic transducer horn to the hollow part. The ultrasonic atomization device according to any one of claims 14 to 25, characterized in that: 27. The ultrasonic atomization device according to any one of claims 14 to 26, wherein the ultrasonic vibration generating means and the ultrasonic vibrator horn are connected so as to be able to move toward and away from each other. 28. Claims characterized in that a connecting portion between the ultrasonic vibration generating means and the ultrasonic vibrator horn that is connected to the ultrasonic vibration generating means so as to be able to freely approach and separate from the ultrasonic vibration generating means is set to be an antinode of vibration. The ultrasonic atomization device according to item 27. 29. Claim 27 or 28, characterized in that an Allen socket or a groove is formed in the hollow part of the ultrasonic transducer horn.
The ultrasonic atomization device described in Section 1.