JP3132283B2 - Liquid injection valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid injection valve used for a fuel injection valve for injecting fuel toward a cylinder of an internal combustion engine, for example.

[0002]

2. Description of the Related Art Generally, an internal combustion engine, for example,
As described in, for example, Japanese Patent Application Laid-Open No. 10-96767, a fuel injection valve as a liquid injection valve is provided. This type of fuel injection valve is provided with a casing, a valve body such as a needle valve which is slidably disposed in the casing, and opens and closes an injection hole at a tip, and this valve body resists the spring force of a valve spring. It comprises an electromagnetic actuator for sucking, and a nozzle member (nozzle adapter) provided at the tip of the casing and having a plurality of injection holes communicating with the injection holes.

The fuel injection valve injects a predetermined fuel toward the intake port in response to a liquid injection signal from a control unit.

Since the fuel injected from the fuel injection valve is supplied to the combustion chamber as an air-fuel mixture, the smaller the particle size of the injected fuel, that is, the finer the fuel, from the viewpoint of stabilizing the combustion state and the like. Is preferred. Therefore, according to the above publication, air for promoting atomization (assist air) is supplied to the injection hole of the nozzle member, and the atomized fuel is injected by the assist air.

On the other hand, without relying on such assist air,
There is also known a fuel injection valve that performs atomization by causing fuels to collide with each other. 19, a nozzle member 200 is mounted in a liquid-tight manner at the tip of a cylindrical casing 100 that constitutes a part of the injection valve main body. Two injection holes, the hole 300 and the other injection hole 400, are formed.

Each of the injection holes 300 and 400 has an injection axis X ₁ -X ₁ and X ₂ -X _{2 corresponding} to an axis OO of the fuel injection valve.
, The fuel injected from each of the injection holes 300 and 400 intersects at a point CP on the axis O-O of the fuel injection valve and collides with each other. The fuel itself is atomized.

[0007]

However, in the above-described liquid collision type injection valve, each of the injection holes 300, 4 is simply provided.
Since only the diameter D of 00 was formed equally, the atomization performance of the liquid was not sufficiently exhibited.

The present invention has been made in view of the problems of the prior art, and a main object of the present invention is to improve the performance of atomization by collision of a liquid. Another object of the present invention is to inject the atomized liquid in a desired direction with high accuracy and to enhance the directivity of the ejection.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to improve the atomization performance by liquid collision based on the unique knowledge of the phenomenon at the time of liquid collision. That is, the configuration of the liquid injection valve according to the present invention includes an injection valve body that opens and closes the injection hole on the distal end side by a valve body, and a pair of injection holes provided on the distal end side of the injection valve body and communicating with the injection hole. with the liquid injection valve and a nozzle member, said sets an injection axis of the respective injection holes so that the liquid injected from each injection hole collide with each other with a strong resonant current
In order to obtain an elephant, the ratio of the square root of the cross-sectional area of each injection hole outlet is set in the range of 1.25 to 3.50.

According to the second aspect of the present invention, there is provided an injection valve body which opens and closes an injection hole on a tip end side by a valve body, and a pair of injection holes provided on the tip end side of the injection valve body and communicating with the injection hole. And a nozzle member having a nozzle member, wherein the injection axis of each of the injection holes is set so that the liquid respectively injected from each of the injection holes collides with each other, and the cross section of each of the injection holes is non-circular. Formed and stronger
It is characterized in that the ratio of the square root of the sectional area of each injection hole outlet is set in the range of 1.25 to 3.50 so that a resonance phenomenon can be obtained .

Further, it is preferable that assist air is supplied to the vicinity of a collision portion of the liquid ejected from each of the ejection holes.

[0012]

The ratio of the square root of the cross-sectional area of the outlet of the injection hole arranged so that the injected liquids collide with each other is 1.25 to 1.25.
By setting the value in the range of 3.50, when fuel injected from each injection hole collides, a strong resonance phenomenon can be generated while ensuring a collision area, so that atomization is promoted.

Each of the injection holes has a non-circular shape, and the ratio of the square root of the sectional area of each of the injection hole outlets is 1.25 to 3.50.
If it is set in the range, the directivity of spray can be provided while atomizing.

Further, by supplying assist air toward the vicinity of the collision portion of the liquid ejected from each ejection hole,
Atomization can be further promoted.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS.

First, FIGS. 1 to 5 relate to a first embodiment of the present invention, and FIG. 1 is an enlarged sectional view showing a main part of a fuel injection valve as a liquid injection valve. Reference numeral 1 is attached to the intake passage so as to face an intake port (both not shown). An electromagnetic actuator 3 composed of a coil or the like is mounted via a yoke 4 in a stepped cylindrical casing 2 which constitutes a part of the injection valve body 1. And a core 5 formed in a substantially cylindrical shape from a magnetic material.

A substantially hemispherical valve body 6 made of a magnetic material is provided in the casing 2. Thin supporting portions 6A having elasticity are integrally formed on both sides of the valve body 6, and the ends of the supporting portions 6A are clamped and fixed between the yoke 4 and the casing 2. The valve element 6 is normally urged by a coil spring 7 and a leaf spring 8 in a valve closing direction. When the electromagnetic actuator 3 is excited by a control signal from a control unit (not shown), the valve element 6 is attracted to the core 5 and opens against the spring force.

On one end side (tip end side) of the casing 2, a valve seat portion 9 for detaching and seating the valve body 6 is formed to protrude radially inward. When the valve element 6 is seated on the valve seat 9, the injection hole 9A is closed, and a fuel reservoir 10 for storing fuel from a fuel supply pipe (not shown) is isolated from a nozzle member 11 described later. It has become.

The nozzle member 11 is mounted in a liquid-tight manner by covering one end side of the casing 2, and one injection hole 12 and the other injection hole 13 having different diameters are formed obliquely. .

[0020] That is, FIG. 2, as shown in FIG. 3, one of the injection hole 12 is formed in a large circle shape whose outlet portion 12a has a diameter dimension D _1, the axis X ₁ -X ₁ is a fuel injection I am bored to incline by a predetermined angle theta ₁ with respect to the axis O-O of the valve. The other of the injection hole 13 is formed in a small circular for its outlet portion 13a has a diameter dimension D _2, the axis X ₂ -X ₂ is a predetermined angle theta ₂ with respect to the axis O-O
It is drilled so that it only slopes. Here, the axis OO of the fuel injection valve substantially coincides with the opening / closing direction of the valve element 6.

As a result, the injection axes X ₁ -X ₁ and X ₂ -X ₂ of the injection holes 12 and 13 intersect at a point CP on the axis O-O. The injected fuel collides. In addition, even when each injection axis X ₁ -X ₁ , X ₂ -X ₂ does not intersect at a single point on the same plane and there is an inter-axis distance, each injection hole 12, It is also possible to provide 13.

The one injection hole 12 and the other injection hole 13 have a sectional area S of the outlets 12a, 13a.
The ratio of the positive square root of ₁ and S ₂ α (α = (S ₁ ) ^1/2 / (S ₂ )
^1/2 ) is set in advance to be a value within the range of 1.25 to 3.50 for the reason described later. In the present embodiment, the aperture ratio α which is the square root ratio of the above-described cross-sectional area is used.
Is set to about 1.5.

Reference numeral 14 denotes an attachment stay for attaching the fuel injection valve to the intake passage.

Next, the operation of this embodiment will be described.

First, in forming the present invention, the relationship between the ratio of the square root of the cross-sectional area of the outlets 12a and 13a of each of the injection holes 12 and 13 (hereinafter referred to as the "diameter ratio α") and the resonance, which were independently found. This will be described with reference to FIG.

That is, FIG. 4 is a characteristic diagram showing a correlation between the aperture ratio α and the resonance which is a nonlinear pull-in phenomenon. It has been found that a non-linear change occurs in the intensity of the resulting resonance.

Specifically, when the aperture ratio α is increased to “1.25”, the resonance intensity is increased to a level equal to or higher than that of the prior art, and when the aperture ratio α becomes “around 1.5”. The strength of the resonance reaches a maximum level. When the aperture ratio α is further increased, the intensity of resonance gradually decreases, and the aperture ratio α becomes “3.
At "5", the resonance intensity is again at the same level as in the prior art.

Therefore, the aperture ratio α is set to “1.25 to 3.5”.
It can be understood that by setting the value to "0", stronger resonance can be obtained than in the prior art, and the atomization of fuel can be achieved by utilizing this strong resonance phenomenon.

On the other hand, FIG. 5 shows the aperture ratio α uniquely found.
FIG. 4 is a characteristic diagram showing a relationship between the fuel collision area and the fuel collision area. When the aperture ratio α is increased from “1”, the ratio of the fuel collision area is quadratic and exponential. descend.

That is, when the aperture ratio α exceeds “3.5”, the area ratio of the portion that does not collide increases (about 90%).
%), One of the sprays penetrates the other and is not atomized.

Therefore, even if the aperture ratio α is set to be more than “3.5”, stronger resonance is not obtained than when the aperture ratio α is “1”, and not only atomization cannot be achieved, but also fuel Since the ratio of the collision area decreases to β ₂ , the total amount of the atomized fuel obtained as a synergistic effect of the both decreases as a result.

On the other hand, when the aperture ratio α is “1.25”,
Although the proportion of the collision area is decreased becomes beta _1, the decrease rate is small.

Therefore, in the present invention, the value of the aperture ratio α is limited to the range of “1.25 to 3.50”.

Thus, when the electromagnetic actuator 3 is excited by the control signal from the control unit and the valve body 6 is sucked into the core 5, the fuel in the fuel reservoir 10 is discharged through the injection hole 9A of the valve seat 9 to each of the fuel holes. It flows into the injection holes 12 and 13 and is injected to the outside through the respective injection holes 12 and 13. Then, each of these injected fuels is
At the intersection CP where O, X ₁ -X ₁ , X ₂ -X ₂ intersect, they collide with each other from an oblique direction. Then, after the fuel is atomized by the above-described resonance phenomenon, it is carried to the intake port together with the intake air.

According to the present embodiment configured as described above,
Based on the fact that was independently found, the diameter ratio α of the outlets 12a, 13a of the injection holes 12, 13 is set to 1.25 to 3.50.
Of each injection hole 12, 1
When the fuel injected from the fuel tank 3 collides, a resonance phenomenon is generated, so that atomization can be improved.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted. This embodiment is characterized in that the cross-sectional shape of each of the injection holes 21 and 22 is formed in an elliptical shape, which is an example of a non-circular shape.

That is, although the illustration of the one injection hole 21 and the other injection hole 22 is omitted, similarly to the injection holes 12 and 13 described in the first embodiment, their axes X ₁ -X ₁ , X
₂ −X ₂ is the axis O− of the fuel injection valve by predetermined angles θ ₁ and θ _2.
Each is inclined with respect to O.

The outlet 21 of each of the injection holes 21 and 22
a, 22a are formed in a non-circular elliptical cross-sectional shape, and the ratio of the square root of the cross-sectional area of both outlets 21a, 22a is the aperture ratio α (α = (S ₂₁ ) ^1/2 / in the present embodiment.
(S ₂₂₎ ^1/2), and this aperture ratio α is 1.25 to 3.
It is set in the range of 50. DL ₁ , D in the figure
L ₂ represents a major axis dimension of the ellipse, DS _1, DS ₂ shows the short diameter of the ellipse.

The present embodiment having the above-described structure also provides substantially the same effects as those of the first embodiment. In addition, in the present embodiment, since the cross-sectional shape of each of the injection holes 21 and 22 is configured to be elliptical, directivity can be imparted to the fuel spray. As a result, atomized fuel can be supplied in an optimal direction corresponding to the shape of various intake ports, and it is possible to prevent the fuel from adhering to the inner wall of the intake port and causing a wall film flow. Can be. In addition,
The non-circular shape is not limited to an ellipse, but may be another shape such as a triangular shape or a rectangular shape. Further, the direction of each of the injection holes 21 and 22, that is, the direction of the major axis of the ellipse in this embodiment is not limited to the state shown in FIG. 6, and may be formed in different directions.

Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

That is, in this embodiment, each of the injection holes 12,
It is characterized in that assist air is supplied in the vicinity of an intersection CP where the fuel injected from 13 collides.
A cylindrical portion 9A provided by slightly extending one end of the valve seat member 9
Has an air injection hole 31 formed therein.
Is opened toward the intersection CP, and the air injection holes 31
Is connected to an intake passage via an air supply passage 32. The air injection holes 31 are designed to blow out assist air at an intersection CP which is a collision point of fuel. Note that the ejection direction of the assist air is not limited to the horizontal direction shown in the drawing, and the assist air may be ejected obliquely from above along the spray direction of the liquid. Further, another air injection hole facing the air injection hole 31 may be provided, and the assist air may be jetted not only from the one injection hole 12 side but also from the other injection hole 13 side.

In this embodiment having such a configuration, substantially the same effects as those in the first embodiment can be obtained. In addition to this, in this embodiment, since the configuration also uses the assist air, further atomization can be promoted.

FIGS. 8 and 9 show a fourth embodiment of the present invention. As shown in this embodiment, after the assist air is added to the first embodiment and the spray is made to collide with the collision wall Y, FIG. , Second
It is also possible to inject the fuel from the injection holes A and B, and according to this, the fuel can be further atomized. In addition,
The second injection holes A and B are provided substantially in line with the extension lines of the injection holes 12 and 13 (on the injection axis), and have a larger cross-sectional area than those of the injection holes 12 and 13.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The one injection hole 41 and the other injection hole 42 according to this embodiment are the same as the injection holes 12 and 1 described in the first embodiment.
Similarly to 3, the injection axes X ₁ -X ₁ and X ₂ -X ₂ are inclined by predetermined angles θ ₁ and θ _{2 with} respect to the axis OO of the fuel injection valve. One injection hole 41 is formed in a large cylindrical shape having a diameter D ₁ , and the other injection hole 42 is formed into a small diameter D _2.
Is formed into a stepped cylindrical shape and a large circle hole 42B having a substantially equal diameter D ₃ to the diameter D ₁ between the small circle hole 42A having. The aperture ratio α according to the present embodiment is defined by the ratio of the cross-sectional area of the outlet 41a of the one injection hole 41 to the cross-sectional area of the outlet 42a of the small-diameter hole 42A of the other injection hole 42. Note that D ₁ and D ₂ in the figure indicate the aperture.

In this embodiment having the above-described structure, substantially the same effects as those of the first embodiment can be obtained.
In addition, in this embodiment, since the other injection hole 42 is formed in a stepped cylindrical shape from the small diameter hole portion 42A and the large diameter hole portion 42B having a diameter substantially equal to the one injection hole 41, each injection hole 42 is formed. 4
The flow rates of the fuel injected from the fuel injection valves 1 and 42 can be made substantially equal, and the degree of freedom in the fuel injection direction can be improved.

Further, as in the sixth embodiment shown in FIGS. 11 and 12, the present invention can also be applied to a structure in which the cross-sectional area of each of the injection holes 12 and 13 changes in the axial direction.
The aperture ratio α, which is the square root of the cross-sectional area of “a”, is 1.25 to 3.
By setting it in the range of 50, atomization can be promoted. In this case, an effect is obtained that processing of each of the injection holes 12 and 13 becomes easy.

Further, in the seventh embodiment shown in FIGS. 13 and 14, a pair of injection holes 12, 13 in the first embodiment is used.
In addition, another pair of injection holes 52 and 53 are provided.
In this embodiment, the fuel injection direction can be divided into two directions by shifting the intersection of the injection axis of one injection hole 12 and 13 and the intersection of the injection axis of the other injection holes 52 and 53 from each other. In this case as well, each of the outlets 12a, 1
The ratio of the square roots of the cross-sectional areas S ₁ and S ₂ of 3a to each outlet 52
a, and the ratio of the square root of the 53a of the cross-sectional area S _52, S _53, are set, respectively, both in the range of 1.25 to 3.50.

Next, FIGS. 15 and 16 show an eighth embodiment of the present invention. In this embodiment, the above-described FIGS.
The same components as those of the first embodiment shown in FIG. 8 and the fourth embodiment shown in FIGS. 8 and 9 are denoted by the same reference numerals, and description thereof will be omitted. The feature of this embodiment is that the intersection CP of the injected fuel is close to or substantially coincides with the inner surface of the collision wall Y.

That is, the fuel injected from each of the injection holes 12 and 13 collides at the intersection CP located on the center of the inner surface of the collision wall Y covering the cylindrical portion 9A. As a result, at the same time when the fuels collide with each other and are atomized, these fuels also directly collide with the collision wall Y, and are further atomized. In addition, atomization of fuel is promoted by the assist air from the air injection holes 31. Here, since this assist air is directed to the intersection CP on the center of the inner surface of the collision wall Y, the collision air Y
The fuel adhering to the inner surface of the fuel cell is also immediately atomized, and the wall film flow does not occur.

The fuel that has been sufficiently atomized by the three-stage or triple atomization process that is performed substantially simultaneously in this manner allows the second injection holes A,
It is sent to the intake port via B. Therefore, unlike the fourth embodiment shown in FIG. 9, each of the second injection holes A,
The axis of B is aligned with the injection axis X ₁ − of each of the first injection holes 12 and 13.
It is not necessary to match X ₁ , X ₂ -X ₂ .

In this embodiment having the above-described structure, the same effects as those of the first and fourth embodiments can be obtained. In addition, in this embodiment, since the intersection CP of the fuel is located on the center of the inner surface of the collision wall Y, atomization due to the collision between the fuels and atomization due to the direct collision of the fuel with the collision wall Y are provided. Can be realized, and the atomization can be performed more effectively than in the fourth embodiment. Further, since the assist air for aiming at the intersection CP is also provided, the third atomization by the assist air can be performed, and the collision wall Y
It is also possible to prevent fuel from adhering to the fuel cell. further,
In the present embodiment, unlike the fourth embodiment, the injection axes X ₁ -X ₁ and X ₂ -X _{2 of} the first injection holes 12 and 13 and the second
The final injection direction is determined by the axes of the injection holes A and B, so that the degree of freedom of the injection direction increases, and the optimum injection direction according to the shape of the intake port, the mounting position of the fuel injection valve, etc. It can be easily obtained, and usability is improved.

Next, FIGS. 17 and 18 show a ninth embodiment of the present invention. This embodiment is characterized in the outlet portion 62a of the injection holes 62 and 63, the 63a, injection axis _{X 1 -X 1, X 2 -X} 2
Are orthogonal to.

That is, the nozzle member 61 mounted on the valve seat member 9 is formed with one injection hole 62 and the other injection hole 63 at an angle, and the outlets 62a, The aperture ratio α, which is the ratio of the square root of the cross-sectional area of 62a,
It is set in the range of 1.25 to 3.50. Also, the outlet portions 62a, 63a of the injection holes 62, 63 according to the present embodiment.
A concave portion 51a that is depressed upward is formed at a substantially central portion of the nozzle member 61 so that the opening surface of the nozzle member 61 is perpendicular to each of the injection axes X ₁ -X ₁ and X ₂ -X ₂ . .

The present embodiment having the above-described structure has the same effects as those of the first embodiment. In addition to this, in the present embodiment, the outlet portions 62 of the respective injection holes 62 and 63 are provided.
Since the configuration is adopted in which the opening surfaces of the nozzles a and 63a are arranged perpendicular to the injection axes X ₁ -X ₁ and X ₂ -X ₂ , the injection direction of the atomized fuel can be set more accurately.

In each of the above embodiments, the case where the present invention is used for a fuel injection valve is exemplified. However, the present invention is not limited to this, and can be applied to, for example, a paint valve for injecting a paint as a liquid.

The combinations of the sectional shapes of the injection holes, the assist air, the collision wall, the number of the injection holes, etc. described in detail in each of the above embodiments are not limited to the above embodiments, and various combinations are possible. is there.

[0058]

As described above in detail, according to the liquid injection valve of the present invention, the atomization of the liquid is promoted by effectively utilizing the resonance phenomenon generated when the liquid injected from each injection hole collides. can do.

Further, since the cross-sectional shape of each injection hole is non-circular, directivity can be given to the spray direction of the liquid, and the liquid can be jetted in the optimum direction.

Further, since the assist air is also supplied in an auxiliary manner, the atomization of the liquid can be further promoted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a fuel injection valve according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing an injection hole and the like in FIG. 1;

FIG. 3 is a plan view in which the nozzle member is enlarged from below.

FIG. 4 is a characteristic diagram showing the relationship between the aperture ratio and the strength of resonance.

FIG. 5 is a characteristic diagram showing a relationship between an aperture ratio and a ratio of a fuel collision area.

FIG. 6 is a plan view similar to FIG. 3, showing a main part of a fuel injection valve according to a second embodiment of the present invention.

FIG. 7 is a sectional view similar to FIG. 2, showing a main part of a fuel injection valve according to a third embodiment of the present invention.

FIG. 8 is a plan view of a nozzle member of a fuel injection valve according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view showing a main part of a fuel injection valve according to a fourth embodiment.

FIG. 10 is a sectional view similar to FIG. 2, showing a main part of a fuel injection valve according to a fifth embodiment of the present invention.

FIG. 11 is a plan view of a nozzle member of a fuel injection valve according to a sixth embodiment of the present invention.

FIG. 12 is a sectional view of a main part of a fuel injection valve according to a sixth embodiment.

FIG. 13 is a sectional view showing a main part of a fuel injection valve according to a seventh embodiment of the present invention.

FIG. 14 is a plan view of a nozzle member according to a seventh embodiment.

FIG. 15 is a sectional view showing a main part of a fuel injection valve according to an eighth embodiment of the present invention.

FIG. 16 is a plan view of a nozzle member according to an eighth embodiment.

FIG. 17 is a sectional view showing a main part of a fuel injection valve according to a ninth embodiment of the present invention.

FIG. 18 is a plan view of a nozzle member according to a ninth embodiment.

FIG. 19 is a cross-sectional view showing a main part of a fuel injection valve according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Injection valve main body 6 ... Valve body 11, 61 ... Nozzle member 12, 21, 41, 52, 62 ... One injection hole 13, 22, 42, 53, 63 ... The other injection hole 32 ... Air injection hole

Claims (3)

(57) [Claims] 1. An injection valve body which opens and closes an injection hole on a distal end side with a valve body, and a nozzle member provided on the distal end side of the injection valve body and having a pair of injection holes communicating with the injection hole. In the liquid injection valve, the injection axis of each injection hole is set so that the liquids respectively injected from each of the injection holes collide with each other , and the cross-sectional area of each injection hole outlet portion is obtained so that a strong resonance phenomenon is obtained. Wherein the ratio of the square root of is set in the range of 1.25 to 3.50. 2. An injection valve body which opens and closes an injection hole on a distal end side with a valve body, and a nozzle member provided on the distal end side of the injection valve body and having a pair of injection holes communicating with the injection hole. In the liquid injection valve, the injection axis of each of the injection holes is set so that the liquids respectively injected from the injection holes collide with each other, and the cross section of each of the injection holes is formed in a non-circular shape. A liquid injection valve , wherein the ratio of the square root of the cross-sectional area of each injection hole outlet is set in a range of 1.25 to 3.50 so as to obtain a strong resonance phenomenon . 3. The liquid injection valve according to claim 1, wherein assist air is supplied to a vicinity of a collision portion of the liquid injected from each of the injection holes.