JP2002303227A - Fluid injection nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent atomized spray from overlapping at an injection target. SOLUTION: Orifices 32a, 32b are double-concentrically disposed, and fuel is injected from each orifice. Each orifice is disposed so as to keep a circle having the same diameter about the orifice contacting with each other. If letting a tilting angle of the inner peripheral side orifice 32a in the thickness direction of the orifice plate 32 as θ1 and a tilting angle of the outer peripheral side orifice 32b as θ2 , an expression θ1 <θ2 is satisfied. Therefore, atomized spray is prevented from overlapping at an injection target, thereby uniformly supplying the atomized spray.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a fluid injection nozzle, for example, an injection nozzle portion of a fuel injection valve for injecting and supplying fuel to an internal combustion engine for an automobile (hereinafter referred to as an engine). Open to the public.

[0002]

2. Description of the Related Art In such a fuel injection valve, "fine atomization of fuel" injected from an injection hole is important from the viewpoints of reduction of fuel consumption, improvement of exhaust emission, stable operation of an engine, and the like. One of the elements. As a method of promoting the atomization of the injected fuel, there are auxiliary atomizing means by collision of air with the injected fuel, heating near the injection hole, etc., but all these atomizing means are expensive. There is a problem.

On the other hand, a fuel injection valve disclosed in US Pat. No. 5,383,607 is known to provide an orifice plate having an orifice at the tip of the fuel injection valve to promote atomization. In this fuel injection valve, a configuration in which a recess is formed at the tip of the needle valve and a configuration in which the tip of the needle is formed flat at right angles to the needle axis direction are disclosed.

[0004]

However, in the fuel injection valve disclosed in the above-mentioned U.S. Pat. No. 5,383,607, even if the atomization is promoted, the spray injected from the orifice overlaps at the injection destination. There was a fear that it would.

An object of the present invention is to provide a fluid ejection nozzle that suppresses atomized fluid spray from overlapping at the ejection destination.

[0006]

According to the fluid ejection nozzle according to the first aspect of the present invention, the orifices are arranged on double concentric circles, and the fluid flowing through the fluid chamber is ejected from each orifice. It is possible to suppress the atomized spray sprayed from the orifice from overlapping at the spray destination, and to supply the atomized spray uniformly.

According to the fluid ejecting nozzle of the present invention, the spray angle of the fluid ejected from the orifice can be increased, so that the fluid can be ejected over a wide range.

According to the fluid injection nozzle of the present invention, since the inclination angle of the outer peripheral orifice is larger than the inclination angle of the inner peripheral orifice, the fluid is ejected from the outer peripheral orifice and the inner peripheral orifice. Sprays do not overlap.
Therefore, the atomized spray can be supplied uniformly.

According to the fluid ejection nozzle of the present invention, the pitch DH between the orifices and the seat diameter DS of the valve member on the facing surface of the orifice plate serving as the flow direction control plate facing the valve member are determined. 1.5 in between
<DS / DH <6. Therefore, the valve member which can be brought into contact with the valve seat is separated from the valve seat, and a substantially disk-shaped fluid chamber defined by the distal end surface of the valve member, the inner wall surface of the valve body, and the opposing surface of the orifice plate. When the fluid flows into the orifice plate, the main flow of the flow is changed in direction by the orifice plate. Arises
As a result, a flow can be created evenly toward the orifice.

A distance h in the axial direction of the valve member when the valve member is lifted between the orifice plate and a tip surface formed at the tip of the valve member and provided at a position facing the orifice.
And the diameter d of the orifice has a relationship of h <1.5d. Moreover, since there is a relationship of H <4d between the vertical distance H between the annular seat portion of the valve seat and the opposing surface of the orifice plate and the diameter d of the orifice, the fluid flow path between the distal end surface and the orifice plate is reduced. The flow can be flattened, and a flow can be created along the opposing surface of the orifice plate to induce a collision between the fluid flows immediately above the orifice.

[0011] Therefore, the fluid ejected from the orifice plate is atomized by turbulence due to the collision, and becomes a spray having directionality.

According to the fluid ejection nozzle of the present invention, the orifice is formed inside a virtual envelope line connecting a position where the direction of the main fluid flow downstream of the contact portion intersects with the facing surface. The main fluid is prevented from being directly injected from the orifice without colliding with the orifice plate. Therefore, the main flow of the fluid colliding with the orifice plate changes its direction along the orifice plate and collides with another fluid flow. The fluid ejected from the orifice is atomized due to turbulence due to collision, and becomes a directional spray.

According to the fluid injection nozzle of the ninth aspect of the present invention, by disposing the orifices such that circles of the same diameter can be secured almost in contact with each other centering on each orifice, the spray injected from each orifice can be formed. Equal areas can be secured. Therefore, since the atomized spray injected from each orifice is suppressed from overlapping at the injection destination, the atomized spray can be uniformly supplied.

According to the fluid ejection nozzle of the present invention, there is a relation of 0.5 <t / d <1.0 between the plate thickness t of the orifice plate and the diameter d of the orifice. If 0.5 ≧ t / d, the directionality of the fluid spray injected from the orifice is not stable. Also, t / d ≧ 1.0
In this case, the atomized spray during the passage through the orifice causes re-adhesion, and the atomized spray cannot be sufficiently atomized. That is, by maintaining the relationship of 0.5 <t / d <1.0, the fluid can be ejected in a predetermined direction, and the fluid spray can be sufficiently atomized.

According to the fluid ejecting nozzle according to the eleventh aspect of the present invention, the flow direction along the orifice plate can be formed in the fluid flow flowing toward the orifice plate, so that the fluid does not directly flow into the orifice.
In addition, it is possible to reduce a decrease in collision energy between fluids due to collision with the orifice plate. Therefore, the fluids collide with each other immediately above the orifice, and promote atomization of the fluid.

According to the fluid jet nozzle of the twelfth aspect of the present invention, since the inner wall surface is a conical slope, the fluid flow further collides evenly. Therefore, atomization of the fluid is further promoted.

According to the thirteenth aspect of the present invention, since the fluid is guided to the front end face and flows uniformly into the fluid chamber along the orifice plate, the strength of the fluid flowing into each orifice is equal. No bias in spraying.

According to the fluid injection nozzle of the present invention, by setting a small orifice diameter, a large number of orifices are provided and a predetermined injection amount is injected, so that the fuel injected from the orifice Can increase the area in contact with the air, thereby promoting more atomization.

According to the fuel supply device of the present invention, the fuel injection device having one of the fluid injection nozzles is connected to the downstream side of the throttle valve and to each of the cylinders. By mounting the fuel injection pipe upstream of the gathering portion of the intake distribution pipe, one fuel injection device can supply a uniform and uniform fuel spray to each cylinder. Therefore, the fuel injection device of the present invention is particularly suitable when mounted on a small engine.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment in which the present invention is applied to a fuel injection valve of a fuel supply device for a gasoline engine.
FIG. 2 and FIG.

As shown in FIG. 3, a fixed core 21 made of a ferromagnetic material is accommodated in a resin housing mold 11 of a fuel injection valve 10 as a fuel injection device. The movable core 22 made of a magnetic material is formed in a cylindrical shape, and is disposed in the internal space of the non-magnetic pipe 23 and the magnetic pipe 24. The outer diameter of the movable core 22 is set slightly smaller than the inner diameter of the nonmagnetic pipe 23,
Are slidably supported by the non-magnetic pipe 23. The movable core 22 faces the fixed core 21 in the axial direction, and is disposed so as to form a predetermined gap with the lower end surface of the fixed core 21.

The non-magnetic pipe 23 is fitted around the end of the fixed core 21 on the movable core side and fixed by laser welding or the like. A magnetic pipe 24 made of a magnetic material and formed in a stepped pipe shape is connected to an end of the non-magnetic pipe 23 opposite to the fixed core. The non-fixed core side of the non-magnetic pipe 23 forms a guide for the movable core 22. As shown in FIG. 1, a tip surface 25a on the fuel injection side of a needle valve 25 as a valve member is formed in a gentle conical convex shape whose diameter gradually decreases toward the fuel flow. Can be annularly seated on the valve seat 31b provided on the valve body 30. At the other end of the needle valve 25, a joint 25d is formed as shown in FIG. Then, the joint 25d and the movable core 22 are laser-welded, and the needle valve 25 and the movable core 22 are integrally connected. A double chamfer as a fuel passage is provided on the outer periphery of the joint 25d.

The valve body 30 is inserted into the magnetic pipe 24 via a spacer 28, and is fixed to the magnetic pipe 24 by laser welding or the like. The thickness of the spacer 28 is adjusted so that the air gap between the fixed core 21 and the movable core 22 has a predetermined value.

The orifice plate 32 made of stainless steel is formed in a cup shape, and is joined to the tip of the valve body 30 on the fuel downstream side of the needle valve 25 by welding, for example, by full circumference welding.

The sleeve 40 is made of resin and is pressed into the outer periphery of the valve body 30 and the orifice plate 32 to protect the orifice plate 32. Orifices 32a, 32b formed in orifice plate 32
Is injected from the opening 40a of the sleeve 40 into the engine.

One end of the compression coil spring 26 is in contact with a spring seat 22 a provided on the movable core 22, and the other end of the compression coil spring 26 is in contact with the bottom of the adjusting pipe 27. The compression coil spring 26 connects the movable core 22 and the needle valve 25 to the lower part of FIG.
b.

The adjusting pipe 27 is a fixed core 2
1 is pressed into the inner circumference. By adjusting the press-fitting position of the adjusting pipe 27 at the time of assembly, the urging force of the compression coil spring 26 can be adjusted.

The electromagnetic coil 50 is wound around an outer periphery of a spool 51 made of resin.
It is provided on the outer periphery of the non-magnetic pipe 23 and the magnetic pipe 24. A housing mold 11 is resin-molded around the outer periphery of the electromagnetic coil 50 and the spool 51, and the housing mold 11 surrounds the electromagnetic coil 50. When an exciting current flows from the terminal 52 to the electromagnetic coil 50 via a lead wire by an electronic control unit (not shown), the needle valve 25 and the movable core 22 are compressed by the compression coil spring 2.
The contact portion 25b is separated from the valve seat 31b by being sucked in the direction of the fixed core 21 against the urging force of No. 6.

The terminal 52 is a housing mold 11
And is electrically connected to the electromagnetic coil 50. The terminal 52 is connected to an electronic control unit (not shown) via a wire harness.

The two metal plates 61 and 62 are provided such that one upper end is in contact with the outer periphery of the fixed core 21 and the other lower end is in contact with the outer periphery of the magnetic pipe 24. Is a member that forms a magnetic path through which the magnetic flux passes. The electromagnetic coil 50 is protected by the two metal plates 61 and 62.

The filter 63 is disposed above the fixed core 21 and is pumped from the fuel tank by a fuel pump or the like to remove foreign matter such as dust in the fuel flowing into the fuel injection valve 10. The fuel flowing into the fixed core 21 through the filter 63 flows from the adjusting pipe 27 to the gap between the two chamfers formed at the joint 25 d of the needle valve 25, and further, the sliding between the valve body 30 and the needle valve 25. It passes through the gap between the four chamfered portions formed in the portion and reaches a valve portion formed by the contact portion 25b of the needle valve 25 and the valve seat 31b. As shown in FIG. 1, the contact portion 25b is
When the user moves away from the fuel cell 35, the fuel flows into the fuel chamber 35 from the opening formed by the contact portion 25b and the valve seat 31b.

The fuel chamber 35 serving as a fluid chamber is formed into a substantially disk shape by being divided by the facing surface 33 of the orifice plate 32, the conical slope 31a of the valve body 30, and the tip surface 25a.

Hereinafter, the needle valve 25 and the valve body 3
0, the structure of the orifice plate 32 will be sequentially described in detail.

(1) Needle Valve 25 As shown in FIG.
5a, the contact portion 25b and the distal end surface 25a and the contact portion 25b
And an annular curved surface 25c connecting the two. Tip surface 25a
Is formed on the inner peripheral side of the contact portion 25b, and the center is located on the axis of the needle valve 25. The axial distance h of the needle valve at the time of needle opening between the distal end surface 25a and the opposing surface 33 of the orifice plate 32 and the orifice plate 32
The diameter d of the orifices 32a and 32b described later is set so as to satisfy the following expression (1).

H <l. 5d, d <0.3 (mm) (1) Particularly, it is preferable to increase the injection amount by providing a large number of orifices with small diameter orifices of about d <0.25. This is because, by allowing a predetermined flow rate of fuel to pass through a number of orifices, the area of the fuel injected from the orifices in contact with the air is increased, thereby further promoting atomization.

Since the orifice diameter is small, it is easy to form a fuel passage between orifices in an orifice plate having a predetermined area. For this reason, as described later, the value of DS / DH can be set in a wide range when the seat diameter of the needle valve 25 is DS and the pitch between the orifices is DH. More preferably, d is about 0.15.

The distance h and the orifice diameter d are set so as to satisfy the expression (1) when the needle valve 25 is separated from the conical slope 31 a of the valve body 30.
5b and the conical slope 31a are separated by an orifice plate 3
The fuel advances to the second side, and the opposing surface 3 of the orifice plate 32
3 is bent toward the fuel chamber 35 to form a fuel flow along the facing surface 33. The fuel flow is divided into a flow directly toward the orifice and a flow passing between the orifices, and the flow passing between the orifices is U-turned toward the orifice by the flow facing the center of the orifice plate. These fuel flows heading toward the orifice from directions opposite to each other in the radial direction collide with each other immediately above the orifice, thereby creating an unstable flow state and promoting atomization of the fuel.

That is, since the distance h and the diameter d are set so as to satisfy the expression (1), the front end face 25a and the opposing face 3
The fuel can flow in a narrow gap with the fuel flow 3, and a collision between the fuel flows along the facing surface 33 can be induced. This makes it possible to increase the energy of collision between fuels and promote atomization of the fuel.

(2) Valve Body 30 The inside diameter of the valve body 30 is reduced from the vicinity of the tip toward the orifice plate 32, and is conical with the inner wall surface 31 forming the fuel passage as the fluid passage on the side of the orifice plate 32. A slope 31a is formed. The contact portion 25b of the needle valve 25 can be seated on a valve seat 31b formed on the conical slope 31a.

The vertical distance H between the valve seat 31b and the facing surface 33 and the diameter d of the orifices 32a, 32b are given by the following equation (2).
Is set to meet.

H <4d (2) That is, the valve seat 31 b, which is the fuel inlet to the fuel chamber 35, is set close to the orifice plate 32.

The diameter of the conical slope 31a is reduced toward the fuel downstream side, and the vertical distance H between the valve seat 31b and the facing surface 33 and the diameter d of the orifices 32a and 32b are set so as to satisfy the equation (2). By setting, when the needle valve 25 and the valve body 30 are separated from each other, the fuel flowing into the fuel chamber 35 through the conical slope 31a from between the contact 25b and the valve seat 31b flows into the opposed surface 33. You can follow along.

(3) Orifice Plate 32 As shown in FIG. 2A, the orifice plate 32 for controlling the direction of spray flow is provided.
Through an orifice 32a having the same diameter d
32b are formed in total. As shown in FIG. 1, the orifices 32a and 32b are imaginary envelope lines connecting positions where the direction of the main fuel flow downstream of the contact portion 25b intersects with the facing surface 33. In FIG. Is formed inside the line of intersection.

As shown in FIG. 2A, the orifice 32
a and 32b are respectively arranged on concentric circles,
The orifice 32a is located inside the orifice 32b. Further, each orifice is arranged so that a circle can be secured in contact with each other at the same radius from the center of each orifice. Therefore, a region where the sprays sprayed from the respective orifices are substantially equal can be secured, so that the sprays hardly overlap at the spray destination.

Further, the orifices 32a and 32b are provided in FIG.
(B) and (C), the orifice plate 32 is inclined away from the central axis toward the fuel downstream side of the orifice plate 32, and the inclination angle of the orifices 32a and 32b with respect to the thickness direction of the orifice plate 32 is θ1. , Θ2, θ1 and θ2 satisfy the following expression (3).

Θ1 <θ2 (3) Since the orifice 32b on the outer peripheral side has a larger inclination angle, if the inclination angles θ1 and θ2 are appropriately set, the sprays sprayed from the respective orifices 32a and 32b overlap each other. It is atomized uniformly without any.

If the number of orifices 32a is n1 and the number of orifices 32b is n2, then n1 = n2. If the distribution of the number of orifices is made equal as described above and the orifices 32a and 32b are arranged so as to be able to secure a circle with the same radius from the center, it is possible to draw a line-symmetric axis without passing through each orifice. Can not. That is, according to the arrangement of the present embodiment, the spray is in one direction.

As shown in FIG. 1, each orifice 32a,
Assuming that the pitch between 32b is DH0, DH1 and the seat diameter of the needle valve 25 is DS, DH0, DH1 and DS satisfy the following equation (4).

1.5 <DS / DH0 <6, 1.5 <DS / DH1 <6 (4) Therefore, when the needle valve 25 and the valve body 30 are separated from each other, the contact portion 25b After flowing into the fuel chamber 35 from between the valve seat 31b and the fuel chamber 35, the fuel flows along the conical inclined surface 31a, and after being turned by the facing surface 33 of the orifice plate 32 without directly flowing into the orifice, flattened with the facing surface 33. A predetermined distance is advanced between the surfaces 25a. Therefore, the fuel can be atomized efficiently without the main flow of the fuel flowing directly into the orifices 32a, 32b. Further, by satisfying the expression (4), the orifices 32a, 32 are set so as not to be too close to the center of the orifice plate 32 and to not spread too much to the outer peripheral side of the orifice plate 32.
b can be arranged. Therefore, each orifice 32a, 3
The strength of the fuel flow flowing into 2b can be made substantially uniform regardless of the flow direction. As a result, the internal energy of the fuel can be efficiently used in the form of turbulence due to collision between flows, and extremely ideal atomization can be realized.

Further, since a uniform collision can be obtained at the center of the entrance of the orifice, a spray can be obtained which is extremely directional along the inclination of the entire side wall forming the orifice.

FIG. 4 shows DS / DH, 1.5d-h, 4d-
The horizontal axis represents each value of H and the vertical axis represents the degree of atomization. Orifice diameter d = 0.15m
m. The measurement results of (A), (B), and (C) in FIG. 4 are obtained by varying two parameters within a range satisfying the other two equations among equations (1), (2), and (4). , The parameters of one remaining expression within the range.

The degree of atomization is determined by SMD (Sauter
(Mean diameter, Sauter mean particle size), and the DS / DH value is in the range of 1.5 to 6 according to FIG. 4 (A), and the 1.5 d-h value is 0 or more according to FIG. 4 (B). From FIG. 4 (C), the SMD value is less than 100 μm when the value of 4d−H (mm) is 0 or more, respectively.
It can be seen that good atomization can be realized.

FIGS. 5 and 6 show a state in which the fuel injection valve 10 is attached to the intake pipe. The engine shown in FIGS. 5 and 6 is a three-cylinder engine. The fuel injection valve 10 is connected to an intake manifold 2 connected to each cylinder on the downstream side of the intake flow.
Is mounted on the intake pipe 1 upstream of the gathering portion 3 of the intake distribution pipes 2a, 2b, 2c and downstream of the throttle valve (not shown). 5 and 6 indicate the spray range of the fuel injection valve 10.

The fuel injection valve 10 of this embodiment can inject finely divided fuel over a wide range as shown in FIGS. 5 and 6, so that a single fuel injection valve can uniformly apply fuel to each cylinder. And can supply the fuel uniformly. Therefore, the number of parts is small and the control of the fuel injection valve is simplified as compared with the case where the fuel injection valve is attached to each cylinder, so that the manufacturing cost is reduced. In particular, it is effective to mount the fuel injection valve 10 of this embodiment on a small engine.

Next, the operation of the fuel injection valve 10 will be described.

(1) When the power supply to the electromagnetic coil 50 is turned off, the movable core 22 and the needle valve 25 are urged downward in FIG. 2 by the urging force of the compression coil spring 26, and the contact portion 25b of the needle valve 25 is opened. The user sits on the seat 31b. Thereby, the fuel injection from the orifices 32a, 32b is shut off.

(2) When the power supply to the electromagnetic coil 50 is turned on, the movable core 22 is attracted to the fixed core 21 against the urging force of the compression coil spring 26.
The fifth contact portion 25b is separated from the valve seat 31b. Thereby, the fuel chamber 3 is opened from the opening of the contact portion 25b and the valve seat 31b.
Fuel flows into 5. The fuel that has flowed into the fuel chamber 35 travels toward the center of the fuel chamber 35. The fuel toward the center collides with each other at the center to generate a radially outward flow, and the radially outward fuel and the central fuel flow collide on the orifices 32a and 32b. Then, the atomized fuel is injected from the orifices 32a and 32b.

(Modification 1) FIG. 7 shows a modification 1 of this embodiment.

Four orifices 71 and 72 are formed concentrically, each of which is eight in total, and the orifice 71 is located on the inner peripheral side of the orifice 72. To inject the same amount of fuel as in the previous embodiment, the diameter of each orifice is larger than in the previous embodiment. In the first modification as well, since the axis of line symmetry cannot be drawn without passing through each orifice, it is a one-way injection.

In the first modification as well, the atomization of the fuel spray injected from the orifices 71 and 72 is promoted as in the above-described embodiment.

(Modification 2) FIG. 8 shows a modification 2 of the present embodiment.

A total of 12 orifices 73 and 74 are formed on the concentric circle, ie, n1 = 4 and n2 = 8, and the orifice 73 is located on the inner peripheral side of the orifice 74. The diameter of each orifice is the same as in the previous embodiment. In the second modification, it is possible to draw a line-symmetric axis without passing through each orifice. That is, according to the arrangement of the second modification, the spray is in two directions.

In the second modification as well, the atomization of the fuel spray injected from the orifices 73 and 74 is promoted as in the above-described embodiment.

(Third Modification) FIG. 9 shows a third modification of the present embodiment.

A total of six orifices 75 and 76 are formed on the concentric circle, ie, n1 = 2 and n2 = 4.
The orifice 75 is formed on the inner peripheral side of the orifice 76. In order to inject the same amount of fuel as in the previous embodiment,
The diameter of each orifice is larger than in the first modification.
In the third modification, an axisymmetric axis can be drawn without passing through each orifice. That is, according to the arrangement of the third modification, the spray is in two directions.

In the third modification as well, the atomization of the fuel spray injected from the orifices 75 and 76 is promoted as in the above-described embodiment.

In the first embodiment of the present invention and the modified examples described above, the diameters of the orifices on the inner and outer peripheral sides are the same, but different values may be used on the inner and outer peripheral sides.

If the expressions (1), (2), and (4) are satisfied, the orifices do not have to be arranged so that circles of the same diameter centering on each orifice can be secured almost in contact with each other. Also, if the orifices are arranged so that circles of the same diameter can be secured substantially in contact with each other with each orifice as the center, formulas (1), (2) and (4) need not be satisfied.

(Second Embodiment) FIG. 1 shows a second embodiment of the present invention.
0 is shown.

The distal end of the needle valve 80 is
a, contact portion 80b, and distal end surface 80a and contact portion 80b
And an annular curved surface 80c connecting the two. Contact part 80b
Can be seated on a valve seat 82a provided on a conical slope 82 as an inner wall surface of the valve body 81. The distal end surface 80a is formed on the inner peripheral side of the contact portion 80b in a plane shape so as to be substantially parallel to the opposing surface 83a of the orifice plate 83, that is, at substantially equal intervals to the opposing surface 83a in the surface spreading direction.

The inner diameter of the valve body 81 is reduced toward the orifice plate 83 from the vicinity of the distal end, and a conical slope 82 is formed on the inner wall surface forming the fuel passage as the fluid passage on the orifice plate 83 side. . The contact portion 80b of the needle valve 80 can be seated on a valve seat 82a formed on the conical slope 82.

The orifice plate 83 is formed with a total of four orifices 84 having the same diameter d and penetrating the orifice plate 83 in the thickness direction. Orifice 84
The direction of the main fuel flow downstream of the contact portion 80b is
A virtual envelope line connecting the position intersecting with 3a, which is formed inside the intersection line between the virtual extension surface of the conical slope 82 and the facing surface 83a in FIG.

The axial distance h of the needle valve 80 between the distal end face 80a and the opposing face 83a when the needle is opened and the diameter d of the orifice 84 of the orifice plate 83 are set so as to satisfy the equation (1). . The vertical distance H between the valve seat 82a and the facing surface 83a and the diameter d of the orifice 84 are set so as to satisfy Expression (2).

The orifice 84 is inclined so as to become farther from the center axis of the needle valve 80 as going toward the fuel downstream side. Assuming that the inclination angle of the orifice 84 with respect to the center axis of the needle valve 80 is θ, θ is given by the following equation (5).
Meets.

15 ° ≦ θ (desirably 20 ° ≦ θ) (5) The pitch of each orifice 84 on the facing surface 83a is D
H, assuming that the seat diameter of the needle valve 80 is DS, DH and DS satisfy the following expression (6).

1.5 <DS / DH <6 (6) With the above configuration, the distal end face 80a and the conical slope 82
The fuel flow flowing into the fuel chamber 85 as a fluid chamber defined by the opposing surface 83a collides with the orifice plate 83 without being directly injected from each orifice 84, and then changes direction and collides with each other immediately above the orifice. From the orifice 84 as in the first embodiment.
The atomization of the fuel spray injected from the fuel cell is promoted.

(Third Embodiment) FIG. 1 shows a third embodiment of the present invention.
It is shown in FIG.

The distal end of the needle valve 86 has a distal end surface 86a and a contact portion 86b. The distal end surface 86a is in contact with the contact portion 8
6b is formed on the inner peripheral side in a convex spherical shape protruding to the fuel downstream side. The contact portion 86b can be seated on the valve seat 82a.

The orifice plate 87 is formed by pressing a flat plate member on which the orifice 88 has been formed in advance, for example, with a punch having a spherical tip to make it concave. The opposing surface 87a of the orifice plate 87 is formed in a concave spherical shape so that the distance from the distal end surface 86a is substantially equal to the shape of the distal end surface 86a. Here, the facing surface 87a
Represents a surface within a range where the orifice plate 87 is exposed to fuel flowing in when the needle valve 86 is separated from the valve seat 82a. Further, that the distance between the distal end surface 86a and the opposing surface 87a is substantially equal means that the distal end surface 86a and the opposing surface 87a
The lengths of the common perpendiculars lowered at the arbitrary needle valve lift positions are substantially equal in the surface spreading direction. The orifice plate 87 penetrates the orifice plate 87 in the thickness direction and has an orifice 88 having the same diameter d.
Are formed in total. The orifice 88 is a virtual envelope line connecting a position where the direction of the main fuel flow downstream of the contact portion 86b intersects with the facing surface 87a. In FIG.
Is formed inside the line of intersection between the virtual extension surface and the opposing surface 87a.

The distance h between the tip surface 86a and the opposing surface 87a when the needle is opened and the diameter d of the orifice 88 are set so as to satisfy the equation (1). Where distance h
The tip surface 86a and the opposing surface 87a
Represents the length of the shortest common perpendicular dropped to A vertical distance H from the valve seat 82a to an imaginary plane passing through the outer peripheral edge of the facing surface 87a and orthogonal to the central axis of the needle valve 86;
The diameter d of 8 is set so as to satisfy Expression (2).

The orifice 88 is inclined away from the center axis of the needle valve 86 toward the downstream side of the fuel. If the inclination angle of the orifice 88 with respect to the center axis of the needle valve 86 is θ, θ is given by the following equation. (5) is satisfied.

Assuming that the pitch of each orifice 88 on the facing surface 87a is DH and the seat diameter of the needle valve 86 is DS, DH and DS satisfy Expression (6).

In the third embodiment, since the orifice plate 87 is recessed on the fuel downstream side in accordance with the shape of the tip of the needle valve 86, the center of the needle valve 86 is depressed when the orifice-formed flat plate member is recessed. The orifice 88 moves further away from the axis. Thus, even if the orifice has a large inclination angle, which is difficult to machine with a flat orifice plate, the orifice angle of the orifice with respect to the center axis of the needle valve is reduced by recessing the orifice plate in accordance with the shape of the tip surface of the needle valve. Can be easily enlarged, and the fuel spray angle can be enlarged. Therefore, it is possible to easily manufacture a fuel injection valve that requires a large spray angle in order to inject the spray directly below the nozzle into the combustion chamber as close as possible to the intake valve.

Further, the fuel flow flowing into the fuel chamber 89 as a fluid chamber defined by the front end surface 86a, the conical inclined surface 82 and the facing surface 87a collides with the orifice plate 87 without being directly injected from each orifice 88. Since the fuel is injected after being changed direction and colliding with each other immediately above the orifice, the atomization of the fuel spray injected from the orifice 88 is promoted as in the first embodiment.

(Fourth Embodiment) FIG. 1 shows a fourth embodiment of the present invention.
It is shown in FIG.

The distal end of the needle valve 90 has a distal end surface 90a and a contact portion 90b. The distal end face 90a is
Ob is formed in a convex conical shape on the inner peripheral side protruding downstream of the fuel. The contact portion 90b can be seated on the valve seat 82a.

The orifice plate 91 is formed by pressing a flat plate member in which the orifice 92 is formed in advance with a punch having a conical tip, for example. The opposing surface 91a of the orifice plate 91 is formed in a concave conical shape so that the distance between the opposing surface 91a and the distal end surface 90a is substantially equal according to the shape of the distal end surface 90a. Here, the facing surface 91a is
This represents a surface within a range that is exposed to fuel flowing in when the needle valve 90 is separated from the valve seat 82a. Further, the tip surface 90
a and the opposing surface 91a are substantially equal to each other when the tip surface 9a
0a and the length of the common perpendicular dropped down to the opposing surface 91a are substantially equal in the surface spreading direction at an arbitrary lift position of the needle valve 90. Orifice plate 9
1, a total of four orifices 92 having the same diameter d are formed through the orifice plate 91 in the thickness direction. The orifice 92 is a virtual envelope line connecting the position where the direction of the main fuel flow downstream of the contact portion 90b intersects with the facing surface 91a. In FIG. 12, the virtual extension surface of the conical slope 82 and the facing surface 9
It is formed inside the line of intersection with 1a.

The distance h between the distal end face 90a and the opposing face 91a and the diameter d of the orifice 92 when the needle is opened are set so as to satisfy the equation (1). Where distance h
When the needle valve is opened, the distal end face 90a and the opposing face 91a
Represents the length of the shortest common perpendicular dropped to A vertical distance H from the valve seat 82a to an imaginary plane passing through the outer peripheral edge of the facing surface 91a and orthogonal to the central axis of the needle valve 90;
The diameter d of 2 is set so as to satisfy Expression (2).

The orifice 92 is inclined away from the central axis of the needle valve 90 toward the downstream side of the fuel. If the inclination angle of the orifice 92 with respect to the central axis of the needle valve 90 is θ, θ is given by the following equation. (5) is satisfied. Assuming that the pitch of each orifice 92 on the facing surface 91a is DH and the seat diameter of the needle valve 90 is DS, DH and DS satisfy Expression (6).

In the fourth embodiment, as in the third embodiment, the orifice plate 9 is adapted to the shape of the tip of the needle valve 90.
Since 1 is recessed downstream of the fuel, the inclination angle of the orifice with respect to the center axis of the needle valve can be easily increased, and the fuel spray angle can be increased. Therefore, a fuel injection valve that requires a large spray angle can be easily manufactured.

Further, the fuel flow flowing into the fuel chamber 93 as a fluid chamber defined by the front end face 90a, the conical slope 82 and the facing face 91a collides with the orifice plate 91 without being directly injected from each orifice 92. Since the fuel is injected after being changed direction and colliding with each other immediately above the orifice, the atomization of the fuel spray injected from the orifice 92 is promoted as in the first embodiment.

In the above-described plural embodiments and the respective modifications of the first embodiment of the present invention, when the needle valve and the valve body are separated from each other, the gas flows from the entire circumference toward the center of the orifice plate. Some of the fuel is redirected at the center of the orifice plate and makes a U-turn toward each orifice. The fuel flow that makes a U-turn from the center of the orifice plate collides with the flow flowing from the outer periphery of the orifice plate to the orifice at the center of the orifice inlet.

Since the strength of the flow flowing into the orifice after making a U-turn at the center of the orifice plate is almost the same as the flow flowing into the orifice from the outer periphery of the orifice plate, it is possible to obtain a uniform collision without vortex around the orifice. Efficient atomization can be achieved. At the same time, fuel collides at the center of the inlet of the orifice, and uniform collision is obtained. Therefore, the directionality of the atomized fuel is well controlled by the orifice.

Since the atomization of the fuel spray injected from the orifice is promoted as described above, the fuel spray is easily mixed with air over a wide range, and the combustion efficiency of the fuel is increased. Harmful substances and fuel consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an injection nozzle portion of a fuel injection valve according to a first embodiment of the present invention.

FIG. 2A is a plan view showing the arrangement of orifices according to the present embodiment, FIG. 2B is a sectional view taken along line BB of FIG.
(C) is a sectional view taken along line CC of (A).

FIG. 3 is a longitudinal sectional view showing the fuel injection valve of the embodiment.

4A is a characteristic diagram showing a relationship between DS / DH and SMD, FIG. 4B is a characteristic diagram showing a relationship between 1.5 dh and SMD, and FIG. 4C is a characteristic diagram showing 4D- FIG. 4 is a characteristic diagram illustrating a relationship between H and SMD.

FIG. 5 is a plan view showing a state in which the fuel injection valve of the present embodiment is mounted on an intake pipe.

6 is a view in the direction of arrow VI in FIG. 5;

FIG. 7 is a plan view showing the arrangement of orifices according to a first modification of the embodiment.

FIG. 8 is a plan view showing the arrangement of orifices according to a second modification of the present embodiment.

FIG. 9 is a plan view showing the arrangement of orifices according to a third modification of the embodiment.

FIG. 10 is a sectional view showing an injection nozzle portion of a fuel injection valve according to a second embodiment of the present invention.

FIG. 11 is a sectional view showing an injection nozzle part of a fuel injection valve according to a third embodiment of the present invention.

FIG. 12 is a sectional view showing an injection nozzle part of a fuel injection valve according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Fuel injection valve 21 Fixed core 22 Movable core 25, 80, 86, 90 Needle valve (valve member) 25a, 80a, 86a, 90a Tip surface 25b, 80b, 86b, 90b Contact portion 30, 81 Nozzle body 31 Inner wall surface 31a, 82 Conical slope 31b, 82a Valve seat 32, 83, 87, 91 Orifice plate 32a, 32b, 71, 72, 73, 74, 75, 7
6, 84, 88, 92 Orifice 33, 83a, 87a, 91a Opposing surface 35, 85, 89, 93 Fuel chamber (fluid chamber)

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[Procedure amendment]

[Submission date] July 26, 2002 (2002.7.2
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

[0012] According to the fluid injection nozzle according to claim 8 of the present invention, the main fluid in the direction of the downstream side of the abutment portion forms an orifice on the inner side of the imaginary hull fault line connecting the position that intersects the opposing surface This prevents the main fluid flow from being directly injected from the orifice without colliding with the orifice plate. Therefore, the main flow of the fluid colliding with the orifice plate changes its direction along the orifice plate and collides with another fluid flow. The fluid ejected from the orifice is atomized due to turbulence due to collision, and becomes a directional spray.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G066 AB02 AD11 BA03 CC26 CC48 4F033 AA13 BA03 DA05 EA01 NA01

Claims (16)

[Claims] A valve body provided with a valve seat on an inner wall surface forming a fluid passage; and a contact portion capable of being annularly seated on the valve seat, wherein the contact portion separates from the valve seat and A valve member that opens and closes the fluid passage by sitting on the valve seat; and a plurality of orifices that are attached to the valve body downstream of the valve member on the fluid side, and that penetrate in a plate thickness direction. An orifice plate, a surface facing the valve member of the orifice plate, a distal end surface formed on an inner peripheral side of the contact portion at a downstream distal end of the valve member, and the inner wall surface. A fluid ejection nozzle forming a disc-shaped fluid chamber, wherein the orifices are arranged on double concentric circles, and a fluid flowing through the fluid chamber is ejected from each of the orifices. Cum nozzle. 2. The fluid according to claim 1, wherein n1 = n2, where n1 is the number of orifices on the inner circumference of the double concentric circle and n2 is the number of orifices on the outer circumference. Injection nozzle. 3. The method according to claim 1, wherein n1 × 2 = n2, where n1 is the number of orifices on the inner circumferential circle of the double concentric circle and n2 is the number of orifices on the outer circumferential circle. Fluid injection nozzle. 4. The fluid ejection nozzle according to claim 1, wherein the orifice is inclined at a predetermined angle with respect to a thickness direction of the orifice plate. 5. The orifice moves in a direction away from the central axis of the valve member toward the downstream side of the fluid.
5. The fluid ejection nozzle according to claim 4, wherein the fluid ejection nozzle is inclined at an angle of not less than. 6. An inclination angle of an orifice on an inner peripheral side circle of the double concentric circle with respect to a thickness direction of the orifice plate is θ1, and an inclination angle of an orifice on an outer peripheral side circle of the double concentric circle is θ2. The fluid ejection nozzle according to claim 1, wherein θ1 <θ2. 7. An annular seat diameter of the contact portion seated on the valve seat is DS, a pitch between the orifices on the facing surface is DH, a diameter of the orifice is d, and the contact portion of the valve seat is provided. 1.5 <DS / DH <6, h <, where H is the vertical distance from the annular seat portion to the facing surface and h is the distance from the distal end surface to the facing surface when the valve member is lifted. The fluid ejection nozzle according to any one of claims 1 to 6, wherein 1.5d and H <4d are simultaneously satisfied. 8. The orifice is formed inside a virtual envelope line connecting a position where a direction of a main fluid flow downstream of the contact portion intersects with the facing surface.
8. The fluid ejection nozzle according to any one of items 7 to 7. 9. The fluid injection nozzle according to claim 1, wherein the orifices are arranged so that circles having the same diameter around the respective orifices can be secured substantially in contact with each other. 10. The fluid ejection nozzle according to claim 1, wherein 0.5 <t / d <1.0, where t is a thickness of the orifice plate. 11. The fluid ejecting nozzle according to claim 1, wherein the inner wall surface has an inclined surface whose diameter decreases in a flow direction of the fluid. 12. The fluid ejection nozzle according to claim 11, wherein the inner wall surface is a conical slope. 13. The apparatus according to claim 1, wherein the distal end surface is provided at a center of a downstream distal end portion of the valve member.
3. The fluid ejection nozzle according to 2. 14. The fluid injection nozzle according to claim 1, wherein the orifice satisfies d <0.3. 15. The fluid ejection nozzle according to claim 14, wherein the orifice satisfies d <0.25. 16. A fuel injection device having a fluid injection nozzle according to any one of claims 1 to 15, mounted on a downstream side of a throttle valve and upstream of a collection portion of an intake distribution pipe connected to each cylinder. A fuel supply device, characterized in that: