JPH0625655Y2 - Ultrasonic liquid atomizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an ultrasonic liquid atomizer suitable for atomizing fuel for vehicles or atomizing water and other liquids.

(Prior Art) Generally, atomization of fuel (gasoline) for an automobile is performed by spraying the fuel into a stream of air through a nozzle.
In this case, the atomized particles have a large particle size of 200 to 300 μm, and the fuel adheres to the inner wall of the pipe through which the air-fuel mixture passes at a considerable ratio, so that even if the fuel spray amount from the nozzle is increased, There was a problem that it was difficult to increase the concentration.

Therefore, as shown in FIGS. 4 and 5, in the related art, the cylindrical vibrating body 2 is arranged with the elastic body 4 interposed in the middle of the pipe 1 through which the fuel mixture passes, and the outer circumference of the cylindrical vibrating body 2 is arranged. The surface is connected with a bolted ultrasonic piezoelectric vibrator (Languvan type vibrator) 3 and the piezoelectric vibrator 3 is excited by a high frequency power source 5 to ultrasonically vibrate the cylindrical vibrating body 2 and communicate with the pipe 1. It has been proposed to atomize the fuel attached to the inner wall of the cylindrical vibrator 2.

In addition, as shown in FIG. 6, there may be a case where the cylindrical vibrating body 2 to which the piezoelectric vibrator 3 is connected is arranged in the pipe 1.

(Problems to be Solved by the Invention) By the way, in the case of the conventional structure shown in FIGS. 4 to 6, the resonance determined by the vibration frequency of the piezoelectric vibrator 3, the circumferential length and the material of the cylindrical vibrator 2, and the like. It is required to exactly match the frequency.

According to an experiment by the present inventor, when the above requirement is not satisfied, the vibration node of the cylindrical vibrating body 2 moves to generate an unnecessary sound wave in the audible range, and the atomization efficiency is greatly reduced. It has been found that vibration becomes unstable and problems such as easy stopping of vibration occur.

However, the resonance frequency of the cylindrical vibrating body 2 also changes depending on the load condition, for example, the amount of droplets attached to the cylindrical vibrating body 2,
Since it is not constant, making the vibration frequency of the piezoelectric vibrator 3 to follow the resonance frequency change of the cylindrical vibrator 2 makes the apparatus very complicated. The pipe diameter of automobiles varies depending on the model, and the diameter of the cylindrical vibrating body 2 inevitably varies, but it is practical to change the shape size of the piezoelectric vibrator 3 in response to this. It's difficult.

(Means for Solving the Problems) In view of the above points, the present invention provides an unnecessary audible range even when the resonance frequency of the cylindrical vibrator does not match the vibration frequency of the ultrasonic piezoelectric vibrator. An object of the present invention is to provide an ultrasonic liquid atomizer that does not generate sound waves and is capable of stable ultrasonic vibration.

In the present invention, the above problem is solved by connecting an ultrasonic transducer to the outer surface of the cylindrical vibrating body and providing an additional mass on the cylindrical vibrating body.

(Operation) In the ultrasonic liquid atomizer of the present invention, the additional mass of the cylindrical vibrating body becomes an absorption point of the ultrasonic vibration, and as a result, the vibration node of the cylindrical vibrating body moves violently and the operation becomes unsuccessful. It is possible to eliminate inconveniences such as stabilization and generation of sound waves in the audible range, resulting in a reduction in atomization efficiency.

(Example) Hereinafter, an example of an ultrasonic liquid atomizer according to the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. In this figure,
Reference numeral 2 denotes a cylindrical vibrating body made of a cylinder such as aluminum or stainless steel, and an ultrasonic piezoelectric vibrator (Languvan type vibrator) 3 is bolted to the outer peripheral surface of the cylindrical vibrating body 2. That is, in the ultrasonic piezoelectric vibrator 3, for example, two piezoelectric elements 12 are sandwiched between the ultrasonic horn 10 and the backing block 11 which are tapered toward the tip, and tightened with a bolt 13 to be integrated. The tip of the ultrasonic horn 10 is welded to the cylindrical vibrating body 2. The piezoelectric elements 12 are electrically connected in parallel and connected to the high frequency power source 5.

An additional mass 15 is integrated with the cylindrical vibrating body 2 by welding or the like at a position symmetrical to the piezoelectric vibrator connecting position. A supporting bolt 16 or the like is fixed to the additional mass 15. By fixing each of the bolt 16 and the small-diameter portion (the portion where the diameter does not change) 18 of the ultrasonic horn 10 by a supporting member 17, the cylindrical vibrating body 2 can be supported by two fulcrums. Become.

In the configuration of the first embodiment described above, the cylindrical vibrating body 2 is arranged in the middle of the pipe through which the fuel-air mixture passes, and the ultrasonic piezoelectric vibrator 3 connected to the cylindrical vibrating body 2 is excited by the high-frequency power source 5 to make the cylinder When the vibrating body 2 is ultrasonically vibrated, the fuel attached to the inner wall of the cylindrical vibrating body 2 communicating with the pipe can be atomized into fine particles. At this time, the additional mass 1 is applied to the cylindrical vibrating body 2.
5 is provided, even if the vibration frequency of the piezoelectric vibrator 3 and the resonance frequency of the cylindrical vibrating body 2 do not match, the additional mass 15 functions as an absorption point of ultrasonic vibration energy,
It is possible to prevent a violent movement of a vibration node in the cylindrical vibrating body 2 and to continue stable ultrasonic vibration. Further, it is possible to prevent the generation of unnecessary sound waves in the audible range and the reduction of the atomization efficiency, which are considered to be caused by the violent movement of the nodes of vibration. Furthermore, the position of the additional mass 15 can be used as a fulcrum for supporting the cylindrical vibrating body 2, and the mechanical support structure of the cylindrical vibrating body 2 can be strengthened.

FIG. 2 shows a second embodiment of the present invention. In this figure,
An ultrasonic piezoelectric vibrator (Languvan type vibrator) 3A, which is bolted, is connected to the outer peripheral surface of the cylindrical vibrator 2. Here, the ultrasonic piezoelectric vibrator 3A has, for example, two or more piezoelectric elements between the ultrasonic horn 10A that is tapered toward the tip and has the through hole 20 in the center axis and the backing block 11. A bolt 13 is screwed into a female screw portion formed in a part of the through hole 20 by sandwiching 12 and tightened and integrated. The tubular tip of the ultrasonic horn 10A is welded to the tubular vibrating body 2. The rest of the configuration is similar to that of the first embodiment described above.

In the second embodiment, the ultrasonic horn 10A welded to the cylindrical vibrating body 2 has a cylindrical shape with a through hole 20 formed therein, and the horn tip portion is different from the case where the horn is screwed to the cylindrical vibrating body. The cross-sectional area at is gradually and continuously changed, and the structure is suitable for preventing accidents such as cracks and damage of the horn.

FIG. 3 shows a preferred specific example of the connecting portion between the cylindrical vibrator 2 and the tip of the ultrasonic horn 10. In this case, a concave portion 25 for welding is formed on the outer circumference of the cylindrical vibrating body 2.
Welding is performed with the horn 10 abutting on the bottom surface of the. By doing so, the amount of the welding material 26 becomes substantially constant, and it is possible to prevent variations in characteristics due to variations in the amount of the welding material 26.

(Effects of the Invention) As described above, according to the ultrasonic liquid atomizer of the present invention, the ultrasonic vibrator is connected to the outer surface of the cylindrical vibrating body and the additional mass is provided on the cylindrical vibrating body. Therefore, it is not necessary to match the resonance frequency of the cylindrical vibrator and the vibration frequency of the piezoelectric vibrator, and unnecessary sound waves in the audible range are not generated, and efficient and stable ultrasonic atomization operation is possible. . Further, the diameter of the cylindrical vibrating body can be freely set according to the application, and the practical effect when applied to a fuel atomizing device of an automobile or the like is extremely large.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view showing a first embodiment of an ultrasonic liquid atomizer according to the present invention, FIG. 2 is a horizontal sectional view showing a second embodiment of the present invention, and FIG. 3 is a cylinder according to the present invention. FIG. 4 is an enlarged plan sectional view showing a preferred specific example of a connecting portion between the vibrating body and the tip of the ultrasonic horn, FIG. 4 is a plan sectional view showing one example of a conventional ultrasonic liquid atomizer, FIG. 5 and FIG. FIG. 6 is a vertical cross-sectional view showing the arrangement of the tubular vibrators. 1 ... Pipe, 2 ... Cylindrical vibrating body, 3, 3A ... Ultrasonic piezoelectric vibrator, 10, 10A ... Ultrasonic horn, 12 ...
Piezoelectric element, 15 ... Additional mass.

Claims (3)

[Scope of utility model registration request] 1. An ultrasonic liquid atomizer characterized in that an ultrasonic transducer is connected to the outer surface of a cylindrical vibrating body and an additional mass is provided on the cylindrical vibrating body. 2. The ultrasonic liquid atomizer according to claim 1, wherein the additional mass is provided at a symmetrical position with respect to the connecting position of the ultrasonic transducers in the cylindrical vibrating body. 3. The ultrasonic liquid atomizer according to claim 1, wherein the connection position of the ultrasonic vibrator and the position of the additional mass serve as a fulcrum for supporting the cylindrical vibrator. .