JPH11200995A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To atomize fuel further and adjust an injection angle easily. SOLUTION: This fuel injection valve 1 is constituted in such a way that fuel F flowing out from a fuel out flow port 20a opened by a needle valve 19 collides against an interference body 25 and is branched into two directions for injection. An orifice plate 24 having a straight orifice 24a of which inner peripheral face is linear along the axial direction X and which is opened circularly is arranged on the fuel out flow side of the fuel out flow port 20a. The interference body 25 is formed into a belt shape on which a fuel collision face 25a is a plane shape crossing the orifice axial direction X orthogonally, provides a clearance between the straight orifice 24a and the face 25a, and is arranged so as to stride and block the center of an opening of the straight orifice 24a. When an inside diameter of the straight orifice is represented by d and a width of the interference body is t, the relation of the straight orifice and the interference body, 0.1<=t/d<=0.3, is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve used for an internal combustion engine, and more particularly to a fuel injection valve which can atomize fuel and easily adjust an injection angle.

[0002]

2. Description of the Related Art Conventionally, fuel flowing out of a fuel outlet port opened by a needle valve collides with an interference body,
As a fuel injection valve that branches and bifurcates and atomizes and injects, those described in JP-A-7-158537 and JP-A-7-163911 are known.

[0003] A fuel injection valve disclosed in Japanese Patent Application Laid-Open No. 7-15837 has a cap provided with a bifurcated injection hole at the tip of the injection valve, and a fuel flow opening with a needle valve. The fuel flowing out of the outlet collides with the branch portion of the two ejection holes in the cap and is injected.

However, in the fuel injection valve described in the above publication,
Even if the fuel flowing out of the fuel outlet collides with the branch portion and is atomized, the fuel is thereafter guided long in the axial direction in each of the two branched jet holes. As a result, the particles were reattached, and the atomization was not sufficient.

In the fuel injection valve disclosed in Japanese Patent Application Laid-Open No. Hei 7-163911, a fuel flowing out of a fuel outlet is passed through an orifice to form a belt-like shape arranged to close the center of the opening of the orifice. They were made to collide with the interference body, branched into two branches, and atomized and sprayed.

However, in the fuel injection valve described in the above publication,
Since the orifice is a tapered orifice that increases the opening area toward the downstream side, the fuel becomes a turbulent flow before colliding with the interfering body and collides with the interfering body in that state, and the injection angle (2 In addition, it was not easy to make an adjustment to increase or decrease the angle between the centers of the respective sprays at the time of branching.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and there is provided a fuel injection valve in which fuel flowing out from a fuel outlet port opened by a needle valve collides with an interfering body, and is branched and branched to be injected. It is another object of the present invention to provide a fuel injection valve which can further atomize the fuel and can easily adjust the injection angle.

[0008]

According to the fuel injection valve of the present invention, the fuel discharged from the fuel outlet port opened by the needle valve collides with the interference body and is branched and injected into the fuel. An injection valve, having a straight orifice on the fuel outflow side of the fuel outlet, the opening area being smaller than the fuel outlet, and the inner peripheral surface being linear along the axial direction, and having a circular opening. An orifice plate is arranged, and the interference body is formed in a band shape having a planar shape in which a fuel collision surface facing the straight orifice is orthogonal to an axial direction of the straight orifice, and a gap is formed with the straight orifice, and The straight orifice is disposed so as to straddle and cover the center of the opening, and the straight orifice and the interfering body are arranged inside the straight orifice. As d, the width of the interference member t
Where 0.1 ≦ t / d ≦ 0.3.

It is desirable that the orifice plate and the interfering body are formed of an integrally connected body.

[0010]

In the fuel injection valve of the present invention, the fuel flowing out of the fuel outlet opened by the needle valve first collides with the interfering object through the straight orifice of the orifice plate.

At this time, since the straight orifice has a smaller opening area than the fuel outlet and the inner peripheral surface is linear in the axial direction, the fuel becomes columnar and the fuel collision surface of the interference body is formed. Collide with In particular, since the opening shape of the straight orifice is not a polygonal shape such as a quadrangle, but a circular shape in which the distance from the central portion to the peripheral edge is equal, the fuel does not spread further in a tapered shape, and the fuel is formed into a liquid straight. , And collides with the fuel collision surface of the interfering object arranged at the center of the orifice.

Since the width of the interference body is smaller than the inner diameter of the straight orifice, the fuel passing through the interference body collides with the fuel collision surface and flows outward along the fuel collision surface. And those that pass beside the interference body without colliding with the fuel collision surface.

However, the fuel collision surface has a plane shape perpendicular to the axial direction of the straight orifice, and the fuel colliding with the fuel collision surface and flowing outward along the surface collides with the fuel collision surface. Instead, the fuel collides with the fuel passing the side of the interfering body in the orthogonal direction, so that the fuel is effectively atomized and injected from the fuel injection valve.

Since the width of the interference body is within a predetermined range (0.1 ≦ t / d ≦ 0.3) smaller than the inner diameter of the straight orifice, the atomization of the fuel is more effectively achieved. Can be achieved. That is, the value of t / d is
If it is less than 0.1, the strength of the interference body is reduced,
If it exceeds 0.3, the spray particle size increases, and atomization of the fuel cannot be achieved.

Further, the fuel that collides with the fuel collision surface and flows outward along the surface is orthogonal to the fuel that passes in the laminar flow state beside the interference body without colliding with the fuel collision surface. The fuel is branched from the fuel injection valve while diverging in a bifurcated manner, and is injected from the fuel injection valve.The interference body is also arranged at the center of the straight orifice,
The injection angle increases and decreases in a linear function in proportion to the width of the interfering body, and within a certain relationship between the inner diameter of the straight orifice and the width of the interfering body (0.1 ≦ t / d ≦
0.3), by changing the width dimension of the interference body, it is possible to easily perform the adjustment for increasing or decreasing the injection angle accurately.

Therefore, in the fuel injection valve according to the present invention, the fuel which flows out from the fuel outlet port opened by the needle valve collides with the interference body, and is branched into a forked shape and injected. Further, the particles can be further atomized, and the adjustment of the spray angle can be easily performed.

In the case where the orifice plate and the interfering body are formed of an integrally connected body, the center of the straight orifice and the interfering body are compared with the case where the orifice plate and the interfering body are separated. Can be made to coincide with the center in the width direction in advance, so that the assembling workability when assembling to the fuel injection valve can be improved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

The fuel injection valve 1 of the embodiment is of an electromagnetic type, and as shown in FIG.
And a valve portion 18 which is disposed at a lower portion and injects fuel when the valve is opened.
And is provided.

The main body 2 has a substantially cylindrical housing 3 in which a bobbin 4 around which an electromagnetic coil 5 is wound is disposed, and a substantially cylindrical fixed core 8 penetrates through the bobbin 4.
Is arranged. A substantially cylindrical movable core 13 is disposed below the fixed core 8. When the terminal 7 connected to the electromagnetic coil 5 is energized, the movable core 13 resists the urging force of a coil spring 12 described later. It is configured to be sucked by the fixed core 8 and rise. Reference numeral 6 denotes a substantially cylindrical metal cover that covers the periphery of the electromagnetic coil 5 and forms a magnetic circuit.

The fixed core 8 has an upper portion formed as a fuel connector 9, and a filter 10 is provided therein. Further, inside the fixed core 8, the insert tube 1 is provided.
The lower end of the insert tube 11 is in contact with the upper end of a coil spring 12 for urging the needle valve 19 downward. Further, a collar 14 is welded to a lower outer periphery of the fixed core 8, and a substantially cylindrical sleeve 16 is welded to a lower outer periphery of the collar 14. A substantially annular stopper 15 is provided in the sleeve 16.

As shown in FIGS. 1 and 5, the valve section 18 includes a needle valve 19, a seat 20, a cover 21, and a control plate 2.
The needle valve 19 is joined to the movable core 13 with the lower end of the coil spring 12 abutting on the upper part.

The seat 20 has a substantially cylindrical shape and is joined to the sleeve 16 so as to cover the periphery of the lower part of the needle valve 19.
The lower end is provided with a fuel outlet 20a that opens in a circular shape so that the fuel F flows out when the needle valve 19 is opened.

When the valve is opened, the fuel F passes through the fixed core 8 from the portion of the fuel connector 9 of the fixed core 8 in the main body 2 through the insert pipe 11, and then passes through the movable core 1.
The fuel is discharged from the fuel outlet 20 a of the seat 20 through the stopper 15, the inner peripheral side of the seat 20, and further injected through the control plate 23.

As shown in FIG. 5, the cover 21 fixes the control plate 23 to the periphery of the fuel outlet 20a of the seat 20, and is welded to the seat 20 with the control plate 23 disposed inside. I have.

As shown in FIGS. 2 to 4, the control plate 23 includes an orifice plate 24 on the side of the fuel outlet 20a,
And an interfering body 25 arranged with a gap H from the orifice plate 24.

The orifice plate 24 is in contact with the periphery of the fuel outlet 20a of the seat 20, and has a straight orifice 24a opened at the center of the fuel outlet 20a.
The straight orifice 24a is configured to have a smaller opening area than the fuel outlet 20a, and to have a circular opening with the inner peripheral surface 24b being straight along the axial direction X.

The interfering body 25 is formed in a band shape having a fuel collision surface 25a facing the straight orifice 24a on the upper surface, leaving a gap H with the straight orifice 24a, and covering the center of the opening of the straight orifice 24a. Is located. Fuel collision surface 25a
Has a plane shape orthogonal to the axial direction X of the straight orifice 24a.

Further, at both ends in the longitudinal direction of the interference body 25,
By increasing the width dimension in an arc shape and closing the gap H,
A connecting portion 26 for connecting the interference body 25 to the orifice plate 24 is arranged.

The control plate 23 of the embodiment is formed from a stainless steel material by using machining such as cutting and grinding, and includes an orifice plate 24, an interference body 25, and
The connecting portions 26 are integrally formed.

In the control plate 23 of the embodiment, when the inner diameter of the straight orifice 24a is d and the width of the interferor 25 is t, the straight orifice 24a and the interfering body 25 are 0.1 ≦ t. /D≦0.3
(See FIG. 6).

In the fuel injection valve 1 of this embodiment, when the terminal 7 is energized, the movable core 13 rises, and the needle valve 19 joined to the movable core 13 moves to the fuel outlet 20a.
, The fuel F flows out of the fuel outlet 20a as shown in FIGS. 5 and 6, and first collides with the interference body 25 through the straight orifice 24a of the orifice plate 24.

At this time, the straight orifice 24a
Since the opening area is smaller than the fuel outlet 20a and the inner peripheral surface 24b is linear in the axial direction X, the fuel F
Become columnar and collide with the fuel collision surface 25a of the interference body 25. In particular, since the opening shape of the straight orifice 24a is not a polygonal shape such as a quadrangle, but a circular shape in which the distance from the central portion to the peripheral edge is equal, the fuel F does not spread further in a tapered shape, and the fuel F And the fuel collision surface 2 of the interfering body 25
It collides with 5a.

Since the width t of the interfering body 25 is smaller than the inner diameter d of the straight orifice 24a, the fuel passing through the interfering body 25 receives the fuel impinging surface 25a.
And fuel Fh flowing outward along the surface,
The fuel Fv passes through the interference body 25 without colliding with the fuel collision surface 25a.

However, the fuel collision surface 25a has a planar shape perpendicular to the axial direction X of the straight orifice 24a, and the fuel Fh that collides with the fuel collision surface 25a and flows outward along the surface is discharged. The fuel Fv that passes through the interference body 25 without colliding with the collision surface 25a collides in the orthogonal direction, and the fuel F is effectively atomized and injected from the fuel injection valve 1.

Since the width t of the interference body 25 is within a predetermined fixed range (0.1 ≦ t / d ≦ 0.3) smaller than the inner diameter d of the straight orifice 24a, the fuel F can be further reduced. Atomization can be achieved. By the way, if the value of t / d is less than 0.1, the strength of the interference body 25 will be reduced, and if it exceeds 0.3, the spray particle diameter will increase and the fuel F
Could not be atomized (see FIG. 7).

Then, the inner diameter d of the straight orifice 24a is set to φ0.17 mm, φ0.23 mm, φ0.33
FIG. 7 shows the results of examining the spray particle diameter when the value of t / d was variously changed by changing the value of t as mm and φ0.46 mm, respectively. The dimension of the gap H is 0.2
mm. The value of the spray flow diameter is 5 to 5
This is the Sauter average particle size on the downstream side of cm.

As can be seen from FIG. 7, the straight orifice 24a and the interfering body 25 are in a range of 0.1 ≦ t / d ≦ 0.
If the relationship is within the range of 3, it can be understood that atomization of the fuel F can be achieved.

Further, in the fuel injection valve 1 of the embodiment, the fuel Fh colliding with the fuel collision surface 25a and flowing outward along the surface collides with the fuel collision surface 25a without colliding with the fuel collision surface 25a. The fuel Fv passes in a laminar flow state and collides in an orthogonal direction, and the fuel F is divided into two branches and is atomized to be injected from the fuel injection valve 1.
5 is also arranged at the center of the straight orifice 24a, the injection angle θ increases and decreases in a linear function in proportion to the width t of the interference body 25, and the inner diameter d of the straight orifice 24a and Within a certain relationship with the width dimension t of the interference body 25 (0.1 ≦ t / d ≦ 0.3)
Therefore, by changing the width t of the interference body 25, the injection angle θ can be easily and accurately adjusted.

The inner diameter d of the straight orifice 24a is set to φ0.17 mm, φ0.23 mm, φ0.33
FIG. 8 shows the results of examining the injection angle θ when the value of t was changed and the value of t / d was variously changed, assuming mm and φ0.46 mm, respectively. In addition, the dimension of the gap H is 0.
It was 2 mm. The spray angle θ is an angle between centers of sprays sprayed in two directions.

As can be seen from FIG. 8, the injection angle θ increases and decreases in proportion to the width t of the interference body 25.

Therefore, in the fuel injection valve 1 of the embodiment, the fuel F that flows out from the fuel outlet 20a opened by the needle valve 19 collides with the interference body 25, and is branched and injected in a forked manner. In 1, the fuel F is
Further atomization can be achieved, and the adjustment of the injection angle θ can be easily performed.

Further, in the embodiment, the orifice plate 24 and the interfering body 25 are constituted by the integral control plate 23 connected to each other, and the orifice plate 24 and the interfering body 25 are separated. Since the center of the straight orifice 24a and the center in the width direction of the interfering body 25 can be matched in advance, the workability in assembling the fuel injection valve 1 can be improved. .

Of course, although this action and effect cannot be obtained, the orifice plate 34 and the interfering body 35 may be separated as in the fuel injection valve 31 of the second embodiment shown in FIG. The fuel injection valve 31 is obtained by assembling an orifice plate 34 and an interfering body 35 with a spacer 37 interposed between a cover 20 and a seat 20 having a fuel outlet 20a opened by a needle valve (not shown). It is. The orifice plate 34 is provided with a straight orifice 34a having a circular opening at the center, and the interference body 35 has a fuel collision surface 35a facing the straight orifice 34a and has an annular support portion 36 around it. It is configured to be connected. The spacer 37 is for providing a gap H between the straight orifice 34a and the fuel collision surface 35a of the interference body 35.

In the fuel injection valve 31 of the second embodiment,
As in the first embodiment, atomization of the fuel F and easy adjustment of the injection angle θ can be ensured.

In the first and second embodiments, the gap H between the straight orifices 24a and 34a and the fuel collision surfaces 25a and 35a of the interference bodies 25 and 35 is equal to the fuel collision surface 25.
It is necessary to set the fuel Fh that has collided with the a. 35a so that the fuel Fh can smoothly move along the surface thereof, and may be set to a size substantially equal to the inner diameter d of the straight orifices 24a and 34a. By the way, the gap H may be set to be twice or more the inner diameter d, but atomization cannot be achieved only by increasing the tip of the fuel injection valves 1 and 31, which hinders downsizing of the fuel injection valve 1. Is not preferred.

As a result of conducting a confirmation test under d ≦ H ≦ 5d, no improvement in atomization was observed. When d> H, smooth injection could not be obtained.

Further, in the first and second embodiments, the length L of the straight orifices 24a and 34a is such that the fuel F injected from the straight orifices 24a and 34a is injected in a laminar flow of a straight cylindrical shape as a liquid. It is sufficient that L / d ≦ 1. Incidentally, the length L may be set to be longer than that, but it is not preferable because merely increasing the thickness of the orifice plates 24 and 34 hinders downsizing of the fuel injection valve 1.

Further, in the first and second embodiments, when increasing the jet flow rate, the straight orifice 24
What is necessary is just to increase the number of a.

[Brief description of the drawings]

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

FIG. 2 is a front view of a control plate used in the embodiment.

FIG. 3 is a bottom view of the control plate.

FIG. 4 is a perspective view of the control plate.

FIG. 5 is an enlarged partial sectional view of the first embodiment at the time of fuel injection.

FIG. 6 is a partial cross-sectional view showing a further enlarged main part of the embodiment at the time of fuel injection.

FIG. 7 is a graph showing a relationship between a spray particle diameter and a t / d value in the same embodiment.

FIG. 8 is a graph showing a relationship between an injection angle and a t / d value in the embodiment.

FIG. 9 is an exploded perspective view showing a main part of the second embodiment.

[Explanation of symbols]

 Reference numerals 1 and 31: fuel injection valve, 19: needle valve, 20a: fuel outlet, 24, 34: orifice plate, 24a, 34a: straight orifice, 25, 35: interference body, 25a, 35a: fuel collision surface, X: (Straight orifice) Axial direction.

Claims (2)

[Claims] 1. A fuel injection valve in which fuel discharged from a fuel outlet opened by a needle valve collides with an interference body and is branched and injected in a bifurcated manner. An orifice plate having a straight orifice having a circular opening with a smaller opening area than the fuel outlet and having an inner peripheral surface formed in a straight line along the axial direction; A fuel collision surface facing the orifice is formed in a band shape having a planar shape perpendicular to the axial direction of the straight orifice, leaving a gap with the straight orifice, and closing over the center of the opening of the straight orifice. The straight orifice and the interfering body are arranged such that an inner diameter of the straight orifice is d and a width of the interfering body is t. In this case, the fuel injection valve satisfies 0.1 ≦ t / d ≦ 0.3. 2. The fuel injection valve according to claim 1, wherein the orifice plate and the interfering body are formed of an interconnected body.