JPH0741179B2 - Liquid jet nozzle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for use in fuel injection valves for internal combustion engines, burners for combustion equipment such as boilers, and liquid atomizers for painting and drying. (Including the liquid substance of (1)) is well mixed with air to obtain a uniform concentration distribution.

[0002]

2. Description of the Related Art In a conventional liquid ejecting nozzle, as shown in FIG. 4, a bag portion 2 is formed at the tip of a nozzle body 1, and a single or a plurality of injection holes 3 that open to the outside from the bag portion 2 are formed. By the sliding of the needle valve 4, the pressurized liquid is jetted from the jet hole 3 through the liquid supply path 5 and the bag portion 2. The injection hole 3 has a substantially cylindrical shape, and its length is the thickness of the tip of the nozzle body 1.

The inventor of the present invention conducted an experiment for observing the concentration distribution inside the spray using the liquid jet nozzle. FIG. 5 is a schematic configuration diagram of the experimental apparatus. 11 is a high pressure container, 12 is a window, 13 is an injection nozzle, 14 is a vacuum pump, 15 is a nitrogen gas cylinder, 16 is an image conversion camera, 17 is a fuel supply device, and 18 is Injection control device, 19 is a laser control device,
Reference numeral 20 denotes a copper vapor laser, and by irradiating the spray injected into the high-pressure container 11 with laser light, the concentration distribution inside the spray was observed from the state of scattered light.

FIG. 6 is a diagram for explaining the spray state. The structure and phenomenon of the spray are roughly divided into four regions, and in the region I, the spray goes straight with a high concentration and hardly spreads, and in the region II, it goes straight. Things began to meander insecurely, Region III
Then, as the meander deforms to form a branch structure, the branches change intervals, repeat division and coalescence, or gradually drop droplets from the surroundings. In Region IV, the branch structure is no longer present, and each fringe is affected by the vortex generated between it and the surrounding gas, and exhibits unique behavior and has a complicated distribution. Thus, the inside of the spray is very non-uniform, and a number of high-concentration stripes of droplets are seen, and this non-uniform high-concentration portion is, for example, a large amount when the liquid is fuel. It leads to the generation of soot.

[0005]

In the above experiment, it was found that the spray having a large turbulence in the jet flow when jetted from the nozzle injection hole has small high-concentration stripes and the spray also spreads widely. . In other words, the concentration distribution is almost uniform, and a large amount of ambient gas is taken in, so that the concentration becomes low.

The present invention is to solve the above-mentioned problems, and by improving the structure of the nozzle, a large turbulence is generated in the jet flow, and the liquid is mixed well with the air to obtain a uniform concentration distribution. An object of the present invention is to provide a liquid jet nozzle capable of performing the above.

[0007]

To this end, a liquid jet nozzle according to the present invention has a needle valve 4 inside.
Formed between main body 1, needle valve 4 and nozzle main body 1
Liquid supply path 5, a bag portion 2 formed between the tip of the needle valve 4 and the tip of the nozzle body 1, and a nozzle hole 3 formed in the nozzle body 1 so as to open from the bag portion 2 to the outside.
And a liquid pressurized by sliding the needle valve 4.
In the liquid ejection nozzle in which the body is ejected from the injection hole 3 via the liquid supply path 5 and the bag portion 2 , the injection hole 3 is formed on the bag portion 2 side.
It is characterized in that it has a plurality of branch holes 3a formed therein and one merge hole 3b that merges with the plurality of branch holes 3a inside the nozzle body 1 . It should be noted that the numbers added to the above configurations are for comparison with the drawings for easy understanding, and the configurations of the present invention are not limited thereby.

[0008]

In the present invention, for example, as shown in FIG. 1C, the flow of a plurality of branch holes 3a is merged into one merge hole 3b, and a large turbulence is generated in the jet flow by utilizing the flow collision at this merge portion. Is generated and is held therein, and is rectified in the confluence hole 3b to generate a jet having large turbulence inside the confluence hole 3b.
Is sprayed in the axial direction, and the sprayed spray mixes well with air to obtain a uniform concentration distribution.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows one embodiment of a liquid jet nozzle of the present invention, FIG. A is a vertical sectional view, FIG. B is a plan view seen from the direction B of FIG. A, and FIG. C is an enlarged sectional view of FIG.

[0010] In FIG 1, the liquid injection nozzle, the internal
A nozzle body 1 having a needle valve 4 and a needle bar
A liquid supply path 5 formed between the lube 4 and the nozzle body 1,
The needle valve 4 includes a bag portion 2 formed between the tip of the needle valve 4 and the tip of the nozzle body 1, and a nozzle hole 3 formed in the nozzle body 1 so as to open from the bag portion 2 to the outside. By the sliding, the pressurized liquid is ejected from the ejection hole 3 through the liquid supply path 5 and the bag portion 2. Although the number of the injection holes 3 is six in the figure, the number is not limited to this and may be one or more.

As shown in FIG. C, the injection hole 3 is formed so that a plurality of branch holes 3a are formed on the bag portion 2 side and the plurality of branch holes 3a are merged into one merge hole 3b. The diameter and length of the branch hole 3a and the confluence hole 3b are arbitrary.

In the present invention, the liquid is provided with a plurality of branch holes 3.
A is merged into one merge hole 3b, a large turbulence is generated in the jet flow by utilizing the collision of the flows in this merge portion, and while maintaining this, the flow is rectified in the merge hole 3b to generate a large turbulence inside. The held jet flow is jetted in the axial direction of the confluence hole 3b, and the sprayed jet can be mixed well with air to obtain a uniform concentration distribution.

FIG. 2 shows a method of manufacturing the branch hole 3a and the confluence hole 3b. In the method of FIG. A, after cutting the branch hole 3a so as to penetrate the nozzle body 1, the confluence hole 3b is cut to the confluence portion. In the method shown in FIG. B, a branch hole 3a is provided on the nozzle body 1 side, and a merging member 7 having a merging hole 3b is attached to the nozzle body 1. It is a method of screwing. In addition to the above production example,
It may be manufactured by casting.

FIG. 3 shows an arrangement example of the branch holes 3a, FIG. A shows an example in which two branch holes 3a are provided, and FIG. B shows an example in which three branch holes 3a are provided. You may increase the number. FIG. C is an example in which the axis of the branch hole 3a and the axis of the confluence hole 3b are not on the same plane, but are displaced so that a swirl flow is generated at the confluence portion and further large turbulence is generated.

[0015]

As is apparent from the above description, according to the present invention, the flow of a plurality of branch holes is controlled by one flow inside the nozzle body.
Use the collision of the flow at this confluence to join the confluence hole.
Generate a large turbulence in the jet flow and hold it
The flow is rectified in the confluence hole and the jet with large turbulence inside is combined.
Injected in the axial direction of the Nagareana, injected spray can obtain air well mixed and uniform concentration distribution.

[Brief description of drawings]

FIG. 1 shows an embodiment of a liquid jet nozzle of the present invention, FIG. A is a vertical sectional view, FIG. B is a plan view seen from the direction B of FIG.
FIG. C is an enlarged sectional view of FIG.

FIG. 2 is a cross-sectional view showing a method of manufacturing a branch hole and a confluence hole in FIG.

FIG. 3 is a plan view showing an arrangement example of branch holes.

FIG. 4 is a sectional view showing an example of a conventional liquid jet nozzle.

FIG. 5 is a schematic configuration diagram of an experimental apparatus according to the present invention.

FIG. 6 is a view showing a spray state for explaining the problems of the present invention.

[Explanation of symbols]

1 ... Nozzle body, 2 ... Bag part, 3 ... Injection hole, 3a ... Branch hole,
3b ... Confluence hole 4 ... Needle valve, 5 ... Liquid supply path, 6 ... Filler, 7 ...
Merging member

Claims (1)

[Claims] 1. A nozzle body having a needle valve inside.
And is formed between the needle valve and the nozzle body.
Liquid supply path, needle valve tip and nozzle body tip
A nozzle formed in the nozzle body so as to open to the outside from the bag ,
The liquid pressurized by sliding the idle valve supplies the liquid.
Road, in the liquid injection nozzle that will be injected from the injection hole via the sack unit, the injection hole merges into a plurality of branch holes and, the plurality of branch hole inside the nozzle body formed in the bag portion side 1 A liquid jet nozzle having two confluence holes.