JPH02293065A - Vibrator for ultrasonic wave atomization - Google Patents

Abstract

PURPOSE:To intermittently supply a medium by connecting the multistep edge parts formed to the outer circumferential part or the inner circumferential part by the projecting spherical surfaces to form the vibrator. CONSTITUTION:A vibrator 1A has an edge part 2A constituted of a plurality of steps whose diameters are gradually made small. The intervals of the respective edges A to F are connected by the projecting spherical surfaces R1 to R4. These spherical surfaces R1 to R4 can be regulated to the same curvature R but also to the mutually different curvature. The height (h) of the edge part 2A, the curvature R of the projecting spherical surface, the diameter (d) of the tip part of the vibrator and an angle alpha are regulated to such dimensions that thin film formation of liquid can be performed. Therefor atomization cutting is made excellent in the edge part 2A of the vibrator and the vibration surface is increased and atomization throughput is increased. Thereby, the stable atomization is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates generally to ultrasonic atomization devices, i.e., ultrasonic injection nozzles, and more particularly to (a) automotive injection valves, such as electronic fnl controlled gasoline. Injection valves or controlled diesel injection valves; (b) fuel nozzles for gas turbines; (c) industrial, commercial, and domestic boilers, heating furnaces, heating furnaces;
Burners for heaters, (d) Industrial liquid sprayers, such as drying sprayers for the purpose of drying liquid materials such as foods, pharmaceuticals, drugs, fertilizers, etc., Neon, temperature control spray, and baking powder sprayer (Ceraminoku) granulation), spray coating equipment, reaction accelerator, and (e
) It relates to a vibrator used in an ultrasonic spray nozzle that is suitable for non-industrial liquid sprayers, such as seismic powder sprayers, disinfectant sprayers, etc., and that atomizes liquid intermittently or continuously. .

[Conventional technology]

Conventionally, in the various fields mentioned above, pressure spray burners or pressure spray burners have been used to atomize, or atomize, liquids (the term "liquid" herein is used to include liquid substances such as suspended solutions). A liquid sprayer is used. The injection nozzle used in such a spray harness or liquid atomizer atomizes the liquid by shearing action between the liquid injected from the nozzle and the outside air (atmosphere). Therefore, in order to atomize the supplied liquid, it is necessary to increase the liquid supply pressure, and the liquid supply equipment, such as bombs and piping, becomes complicated and large.

Furthermore, the amount of liquid to be injected can be adjusted by changing the pressure of the supplied liquid or
This is done by changing the area of the nozzle's injection port, but with the former method, the state of atomization worsens during bottom flow (at low pressure),
As a countermeasure to this problem, in medium to large boilers, air or steam is used in combination to atomize the liquid fuel supplied. For this purpose, devices have become increasingly complex and large.

On the other hand, in the latter method, the structure of the nozzle is extremely complicated, and its adjustment and maintenance are difficult.

In order to improve these drawbacks of conventional injection nozzles, attempts have been made to apply pressure to the injection port of the injection nozzle to inject a liquid material and at the same time apply ultrasonic vibrations to the granular material. However, conventional liquid injection nozzles using ultrasonic waves have an extremely small amount of spray, and cannot be used in the above-mentioned injection nozzles that require a large amount of atomization.

The present inventors, in order to achieve atomization of a large volume of liquid,
As a result of numerous studies and experiments on the mechanism of liquid atomization by ultrasonic waves and the shadow shape of ultrasonic transducers, we found that an edge section is provided at the end of the ultrasonic transducer, and a thin film of liquid is supplied to the core edge section. (Refer to Japanese Patent Application Laid-Open No. 60-222552)
．． To explain this further with reference to FIG. 7, the injection valve 10 includes an elongated, generally cylindrical valve body 8 having a central hole 6 at its center. A vibrator l is placed through the center hole 6 of the valve body 8,
The vibrator l includes an upper main body portion 1a, an elongated cylindrical vibrator shaft portion 1b having a smaller diameter than the main body portion 1a, and the main body portion 1a and the shaft portion 1.
It has a connecting part 1c that connects b. The main body portion 1a is provided with a flange 1d having a larger diameter, and the flange 1d connects to a shoulder portion 12 formed at the upper end of the valve body 8 and a bolt (not shown) to the upper end of the valve body 8. ) and a vibrator holder 14 attached to the valve body 8.

At the tip of the vibrator 1, that is, at the tip of the shaft portion 1b, an edge portion 2 having a shape as illustrated in detail in FIG. 6 is formed. Further, one or more supply passages 4 for supplying fuel to the edge portion 2 are formed below the valve body 8.
Liquid fuel is supplied to the fuel supply hole 16 of the supply passage 4 from a fuel supply source (not shown) via an external supply pipe (not shown). The amount of fuel and supply/stop of the fuel are controlled by a supply valve (not shown) provided in the external supply pipe.

In the above configuration, the vibrator 1 is continuously vibrated by the ultrasonic vibration generating means 100 operatively connected to the main body portion 1a. Therefore, when the liquid fuel is supplied to the edge portion 2 via the pipe, the supply valve and the supply passage 4, the liquid fuel is atomized and injected outward. Conventionally, as shown in FIG. 6, the edge portion 2 of the vibrator 1 has an annular step-like shape with several M steps in which the diameter in the width direction is reduced, and the height of the edge portion of the vibrator 1 (h ) and convergence (W) are
The size and shape are such that the liquid can be made into a thin film, and the flow of the body and the body can be dammed.

When liquid fuel is supplied to the edge portion 2 with the above configuration, the longitudinal vibration applied to the vibrator 1 causes a state in which the flow of fuel is cut off at each energizer, and the supplied fuel is atomized. A part of the fuel is first crushed in the first stage's enoge part A, and excess fuel that cannot be processed in the first stage's edge part A is sent to the second stage's edge part B1 and third stage. It is sent to the edge portions C... and processed at each edge portion.

Therefore, when the fuel flow rate is large, the effective area required for atomization becomes large and multi-stage edges are required.
If the number of stages is small, atomization is completed without using multiple stages. Therefore, when such a vibrator 1 is used, the number of stages required for atomization changes when the flow rate changes, and conditions such as film thickness at the position where atomization is performed are approximately the same at each stage, so the number of stages necessary for atomization changes. The resulting droplet size becomes uniform.

Furthermore, since this vibrator can cover all the flow rates normally required for atomization, atomization of various liquid materials can be achieved regardless of whether it is intermittent atomization or continuous IT-Am atomization. [Problems to be Solved by the Invention] However, when the conventionally shaped vibrator 1 is used, for example, in an injection valve for a diesel engine,
, C, D, and E are discontinuously connected, recesses A', B'C'-D' are formed between each stage, and these recesses A', B'C', A liquid, ie, fuel F, is held in D'.

Even during the vibration of the vibrator 1, the injection for atomization of the fuel F held in such a recess is not completed within a short period of time within one cycle of the engine (compression, expansion, exhaust, and intake strokes). The combustion time of fuel droplets after injection until the exhaust process is shortened, and incomplete fuel also causes soot to be generated. In addition, after the vibration of the vibrator 1 is stopped, the particles are not atomized and remain at the tip of the vibrator 1, and as time passes, they become droplets and drip from the vibrator 1 into the engine ring. A so-called phenomenon of poor spray cutting occurs. Such a phenomenon is a problem that must be avoided as much as possible in injection valves for diesel engines.

The present inventors believe that this phenomenon is caused by each oscillator type A. B
, CSD, and E are connected by a continuous curve, and the recesses A, B', C', and D' are such that fuel F is held between each stage.
We have found that the problem can be solved by eliminating the .

The present inventors further conducted research experiments on the shape of the vibrator of such an ultrasonic jet nozzle, and found that the shape of the vibrator was as follows.
It has been found that this has a large impact on the atomization of the liquid (1) (spray amount) and the injection (spray) cut-off (short-term injection) required when used in, for example, a diesel injection valve.

The present invention is based on such new knowledge, and relates to the improvement of vibrators used in various ultrasonic atomization devices. The purpose is to provide a vibrator for ultrasonic atomization that can supply a medium to Another object of the present invention is to provide an ultrasonic atomization vibrator that can supply a large volume of liquid and atomize, or inject, a large amount of liquid compared to conventional injection nozzles and ultrasonic injection nozzles. That's true.

Another object of the present invention is to provide an ultrasonic atomization camera that eliminates liquid retention and improves the spray cut required for, for example, diesel injection valves.

Another object of the present invention is to provide an ultrasonic atomization vibrator that can achieve stable granulation in which the state of granulation (flow rate, particle size) does not vary depending on the properties of the supplied liquid, especially the viscosity. That's true.

Measures for Solving Problem c] To this end, the ultrasonic atomizing vibrator of the present invention has a multi-stage edge portion of two or more stages formed on the outer circumference or the inner circumference, and liquid is supplied to the edge portion. In the ultrasonic atomization vibrator for atomizing liquid, the multistage edge portion is formed by connecting convex spherical surfaces.

[Function] With the above configuration, there is no formation of concave parts in the two edge parts of the vibrator, where liquid accumulates, as in the conventional case, and therefore the spray is easy to clean and is generated from the convex spherical surface. Since the spray is blown away in the radial direction, the spray does not collide and coalesce, the particle size does not become coarse, and the vibration surface increases and the spray throughput increases.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. Although the present invention can be suitably used in nozzles for various purposes as described above, the present invention will be explained in connection with an electronic injection valve for a diesel engine.

FIG. 1 shows an embodiment of an ultrasonic transducer according to the present invention,
It is used in the ultrasonic injection valve explained in FIG. The vibrator IA of this embodiment has a plurality of first stages whose diameters are gradually reduced.
In the figure, the edge portion 2A has an annular step shape consisting of six steps.
The major difference is that the radii A, B, C, D, E, and F are connected by convex spherical surfaces R1, R2, R3, and R4.

The convex spherical surfaces R1, R2, R3, and R4 all have the same curvature R
It is also possible to have different curvatures. Of course, the edge portion 2A is not limited to six stages, but may have two, three, or four stages, or even more.

The height (h) of the edge portion 2A, the curvature (R) of the convex spherical surface, and the diameter (d) or angle (α) of the tip of the vibrator are such that the liquid can be thinned and the liquid can flow. The dimensions are such that it dams up the

With the above configuration, there is no formation of a concave portion in the edge portion 2A of the vibrator, where liquid accumulates, as in the conventional case, and therefore, the spray can be cut off very well. Furthermore, according to the vibrator of the present invention, the spray generated from the convex spherical surface is scattered in the radial direction, so that the spray does not collide and coalesce.
The particle size does not become coarse. Another advantage is that the vibration surface increases and the amount of spray throughput increases. The vibrator of the present invention is not limited to the vibrator having the shape shown in FIG. 1, but may be a vibrator as illustrated in FIGS. 2 to 5, for example. At the tip of the vibrator IB shown in FIG. 2, an annular edge portion 2B having the same diameter and having one or more stages, five stages in this embodiment, is formed. The shape of the edge portion 2b when viewed from the direction of the arrow X is not limited to a circular shape, but may be triangular, square, or other polygonal shapes.

FIG. 3 shows a vibrator IC according to another embodiment of the present invention, which differs from the vibrator IA in FIG. 1 in that an edge portion 2C is formed to gradually expand.

FIG. 4 and FIG. 5 show vibrators ID and IB according to still another embodiment of the present invention, in which the lower edge portion is formed in one or more stages in the inner peripheral portion of the tip of the vibrator. In this embodiment, liquid is supplied to the edge portions 2D and 2E via a liquid supply passage 4 formed through the vibrators ID and IE.

What is important in the present invention is that there are no steps or recesses on the edge surface that would retain the liquid in the liquid flow path from the edge to the next edge.

One specific condition and various dimensions of the ultrasonic spray exposure apparatus according to the present invention explained above are as follows. This configuration made it possible to achieve large-capacity granulation. Output of ultrasonic generating means: 10W Vibrator amplitude: 34μm Frequency: 38KHz Vibrator shape and dimensions (vibrator in Figure 1) Diameter and curved surface (curvature R) of the enamel part 1st stage: Diameter (D++) 7 Tsuru 2nd stage: R 0.5mm 3rd stage: R 0.5m 4th stage: R O. 5 Dragon 5th Dan: R O. Height of each tier of 5 cranes (h): 2m Fuel oil capacity
: Light oil flow: 0.06 cd/injection Injection pressure: l ~ 70 kg/cd Temperature
: Material of the room-temperature vibrator : Titanium [Effects of the invention] As explained above, the vibrator according to the present invention, which has a specific shape, has the following properties: The spray does not collide and coalesce, the particle size does not become coarse, the spray cut of the liquid is extremely improved, and the vibration surface is increased, making it possible to spray a large volume, and furthermore, the properties of the supplied liquid are improved. In particular, it is possible to provide an ultrasonic atomization device that can achieve stable atomization in which the state of atomization (flow rate, particle size) does not vary depending on viscosity.

[Brief explanation of the drawing]

1, 2, and 3 are partial front views showing various embodiments of the ultrasonic atomization vibrator according to the present invention. Fourth
FIG. 5 is a partial sectional view showing another embodiment of the ultrasonic atomization vibrator according to the present invention. FIG. 6 is a partial front view of a conventional atomization edge portion, and FIG. 7 is a schematic cross-section of an ultrasonic injection valve equipped with a conventional vibrator that can use the ultrasonic atomization vibrator according to the present invention. It is a diagram. IA~IE... vibrator, 2A~2E... edge part,
R1, R2, R3, R4... Convex spherical surface, 4... Liquid supply passage, 10... Spray nozzle, 100... Ultrasonic vibration generating means. Norihito Izu Toa Fuel Industries Co., Ltd. Representative Patent Attorney
Hiroki Shirai (5 others) 4th Figure 5N 2ε

Claims (1)

[Claims] 1) In an ultrasonic atomization vibrator for forming two or more multi-stage edge parts on the outer peripheral part or the inner peripheral part, and supplying liquid to the edge parts to atomize the liquid, the multi-stage edge parts are A vibrator for ultrasonic atomization, characterized in that it is formed by connecting convex spherical surfaces.