DE60119007T2 - Fluid injector - Google Patents

Description

BACKGROUND THE INVENTION

1. Field of the invention:

The The present invention relates to a fluid injection nozzle with a Injection port plate and on a fuel injection nozzle for injection of fuel in an internal combustion engine.

2. Description of the related state of the technique:

From the prior art, a fuel injection valve is known in which a thin injection port plate having a plurality of injection ports is disposed on the downstream side fuel of a valve unit formed of a valve element and a valve seat, so that the fuel is injected from the individual injection ports. Like this in the 13A and 13B is shown, it is common for the injection inlets 301 located in the injection port plate 300 are formed to have a constant diameter from the injection port inlet to the injection port outlet. Fuel entering the injection port 301 with the constant diameter does not distribute along an injection port inner circumference 302 , and it is injected as a liquid column. The liquid column of the fuel is hardly atomized. In US 4,907,748, in contrast, an injection port plate is disclosed in which the injection ports are radially enlarged to diverge toward the downstream side of the fuel.

however diverge the divergent injection ports as described in US 4,907 748 are substantially homogeneous to the downstream side of the fuel, allowing the fuel to pass through the injection ports should occur, with the injection port inside the injection port plate which contacts the injection ports and injects them into liquid columns will be without it spreading. This makes it difficult to fuel sufficiently to atomize.

In another prior art, there has been proposed an electromagnetic fuel injection valve (JP-9-14090A or the like) provided with a mechanism (for example, an orifice plate 406 ) for promoting the atomization of a fuel spray to be injected at a correct timing near the intake valve of the internal combustion engine such as an internal combustion engine.

The electromagnetic fuel injection valve is constructed as shown in FIGS 22 . 23A and 23B is shown, comprising: a cylindrical valve body 403 with an opening 401 at the middle portion of its front end and a valve seat 402 on the upstream side of the opening 401 ; a needle valve 405 in that slidable in the valve body 403 is included and a seat section 404 has on the outer periphery of its front end portion so that it to the valve seat 402 strikes; and the orifice plate 406 located on the front end side of the valve body 403 to close the opening 401 is arranged. In the opening plate 406 are also round injection ports (openings) 408 formed to be inclined at a predetermined angle A (degree) from their fuel inlets to their fuel outlets to the upstream side, with respect to the fuel flow direction of a fuel passage 407 ,

However, in the electromagnetic fuel injection valve of the prior art, flows in the fuel passage 407 located between the front end side of the needle valve 405 and the channel wall side of the orifice plate 406 is formed, the fuel between the valve seat 402 and the seat portion 404 has flowed along the channel wall side of the orifice plate 406 to the fuel inlet of the opening 408 , and then into the opening 408 ,

Like this in the 23A and 23B however, it becomes a liquid column section 409 in the flow of fuel in the opening 408 set up. As the capacity of this liquid column section 409 the fuel flow is greater, the area of the liquid column section 409 the fuel flow is smaller, so that the area that comes in contact with the air, is reduced so that the cleavage is prevented. As a result, there arises a problem of deterioration of the effect of promoting the atomization of the fuel spray, which is in the vicinity of the inlet valve from the opening 108 is injected through the orifice plate 406 is trained.

The publication DE 199 13 317 A1 discloses a fluid injection nozzle having a valve body with an inner periphery forming a fluid passage and converging to a downstream side of the fluid and having a valve seat on the inner circumference. Moreover, an injection port plate is disposed on the downstream side of the fluid passage of the valve seat and has an injection port for injecting a fluid to flow out of the fluid passage. A valve member is provided for closing the fluid passage when it is seated against the valve seat and for opening the fluid passage when not seated on the valve seat. The injection connection axis, the one Center of a fluid inlet connects to a center of a fluid inlet of the injection port is inclined with respect to a center axis of the injection port plate. Two cut lines between a virtual plane including the injection port plate and normal to the injection port plate and an injection port inner periphery of the injection port plate forming the injection port are inclined in the same direction as the injection port axis with respect to the central axis. Moreover, a first cut line on the side of an obtuse angle is formed through the injection port axis and an end side on the side of the fluid inlet of the injection port plate with a first inclination angle θ1 with respect to the center axis, and a second intersecting line is on the side of an acute angle through an injection port axis and the end side on the fluid inlet side is formed with a second inclination angle θ2, where θ1 <θ2.

The document US-5 540 200 discloses a plurality of embodiments of a fuel injection valve with many embodiments, which are similar to the design according to the document DE 199 13 317 are designed. In addition, this document discloses embodiments with injection holes, which are aligned against the definition of the direction in the document DE 199 13 317 A1 is looked at. These embodiments have partial injection holes that show an increasing diameter.

SHORT VERSION THE INVENTION

It It is the object of the present invention to provide a fluid injector for atomizing a fluid spray to provide as defined in claim 1.

Of the Injection connection is diametrically on the injection connection axis to the side of the fluid outlet so enlarged that the surface area the injection port circumference greater than the area of the injection port with the same diameter. In addition, occurs Never make a mistake on that of the fuel in the injection port flow should come in contact with the injection port inner circumference, which contains the first cut line, so he spreads while he led becomes. Therefore, the fluid to be injected from the injection port not to the liquid column, but it becomes a liquid film distributed so that it is atomized in a simple manner.

According to one second aspect of the present invention is the injection port arranged several times, so that the injection rate for an injection port is reduced, so that reduces the injection port diameter is. Therefore, it is possible the atomization promote the fluid spray.

According to one Third aspect of the present invention is the fluid chamber, the directly over the fluid inlets the injection connections is formed diametrically larger than the open end at the downstream Side of the fluid that is formed by the inner circumference. In addition, the result Injection ports at their fluid inlets in the inner circumference and the outer circumference the virtual shell, At the virtual level, extending from the inner circumference to the downstream Side of the fluid extends, the injection port plate cuts. The fluid flows from the outer circumference to the inner periphery of the injection port plate in the inner injection ports, the are positioned at the side of the inner periphery of the virtual shell, and the fluid flows from the inner periphery to the outer periphery the injection port plate in the outer injection ports, the on the outer peripheral side of the virtual shell are positioned. The fluids flow in the outlet directions into the inner injection ports and the outer injection ports, so that an overlap of the fluid spray from the inner injection ports with the fluid spray the outer injection ports directly below the injection ports is prevented. Therefore, the atomization of the fluid spray is promoted.

SUMMARY THE DRAWINGS

Further Features and advantages of the present invention will become more readily apparent Way from the following detailed description of its preferred embodiments when considered together with the accompanying drawings where:

1A shows an enlarged sectional view of a fuel injection nozzle of a fuel injection valve (first embodiment);

1B shows a plan view of an injection port plate (first embodiment);

2 shows a cross-sectional view of a fuel injection valve (first embodiment);

3 shows an enlarged view of an environment of an injection port (first embodiment);

4A shows a cross-sectional view along a line IVA-IVA in the 3B (first embodiment);

4B shows a cross-sectional view along a line IVB-IVB in the 4A (first embodiment);

5 shows a section line between a virtual plane that is perpendicular to an injection port axis, and an injection port inner circumference (first embodiment);

6 shows a cross-sectional view of a modification with a different divergence of the injection port at the same section, as in the 4B is shown (first embodiment);

7A shows a cross-sectional view of a fuel flow (first embodiment);

7B shows a schematic perspective view of the fuel flow (first embodiment);

8A FIG. 14 is a characteristic diagram showing a relationship between θ1 and the fuel particle size (first embodiment); FIG.

8B FIG. 14 is a characteristic diagram plotting a relationship between .theta.3 and the fuel particle size (first embodiment); FIG.

8C Fig. 14 is a characteristic diagram showing a relationship between t / d and the fuel particle size (first embodiment);

9A shows an enlarged cross-sectional view of a fuel injection nozzle of a fuel injection valve (second embodiment);

9B shows a plan view of an injection port plate (second embodiment);

10 shows a cross-sectional view of a fuel injection nozzle (third embodiment);

11A shows an enlarged cross-sectional view of a fuel injection nozzle of a fuel injection valve (fourth embodiment);

11B shows a plan view of an injection port plate (fourth embodiment);

12A shows an enlarged cross-sectional view of a fuel injection nozzle of a fuel injection valve (fifth embodiment);

12B shows a plan view of an injection port plate (fifth embodiment);

13A shows a cross-sectional view of a fuel flow (prior art);

13B shows a schematic perspective view of the fuel flow (prior art);

14 shows a cross-sectional view of a whole electromagnetic fuel injection valve (sixth embodiment);

15 shows a cross-sectional view of an essential part of the electromagnetic fuel injection valve (sixth embodiment);

16 shows a plan view of a channel wall side of an orifice plate (sixth embodiment);

17A Fig. 10 is an enlarged plan view showing a vicinity of a fuel inlet of an orifice (sixth embodiment);

17B shows a cross-sectional view along a line XVIIB-XVIIB in the 17A (sixth embodiment);

18 shows a view of I in the 17B (sixth embodiment);

19A shows a cross-sectional view of a fuel flow in a fuel passage and an opening (sixth embodiment);

19B Fig. 11 is an illustrative view of a liquid column portion of the fuel flow in the opening (sixth embodiment);

20 shows a cross-sectional view of an essential part of an electromagnetic fuel injection valve (seventh embodiment);

21 shows a plan view of a channel wall side of an orifice plate (seventh embodiment);

22 shows a cross-sectional view of an essential part of an electromagnetic fuel injection valve (prior art);

23A shows a cross-sectional view of a fuel flow in a fuel passage and an opening (prior art), and

23B shows an illustrative view of a liquid column portion of the fuel flow in the opening (prior art).

The 14 to 21 represent examples that are not in accordance with the present invention.

DETAILED DESCRIPTION THE PREFERRED EMBODIMENTS

A Variety embodiment of the invention, showing their modes of operation, will be referred to on the attached Drawings described.

(First embodiment)

In the 2 an example is shown in which a fluid injection nozzle according to a first embodiment of the invention is used for a fuel injection valve of a gasoline engine.

A housing 11 a fuel injection valve 1 is cast from a synthetic resin, which is a magnetic tube 12 , a stator core 30 , one around a bobbin 40 wound coil 41 and the like. A valve body 13 is to the magnetic tube 12 joined by laser welding or the like. A nozzle needle 20 as a valve element is so in the magnetic tube 12 and the valve body 13 fit that it is movable back and forth, and their stop section 21 can be attached to a valve seat 14a be placed on an inner surface 14 of the valve body 13 is trained. The inner surface 14 is with a conical shape on the inner peripheral wall of the valve body 13 designed to be such a fuel channel 50 as a fluid channel and converges to the downstream side of the fuel.

Like this in the 1 is shown, is the injection nozzle of the fuel injection valve 1 designed so that they are the valve body 13 , the nozzle needle 20 and an injection port plate 25 includes. A fuel chamber 51 as a fluid chamber is through the front end side 20a the nozzle needle 20 , one end side 26 on the side of the fuel inlet of the injection port plate 25 and the inner surface 14 divided, and it is formed with a flattened generally disc-shaped shape.

The nozzle needle 20 is on its front end side 20a formed with a flat shape. Like this one of the 2 is shown is a joining section 22 like him at the nozzle needle 20 on the other side of the stop section 21 is provided to a movable core 31 together. A stator core 30 and a non-magnetic tube 32 as well as this non-magnetic tube 32 and the magnetic tube 12 are individually joined by laser welding or the like.

At an end portion on the downstream side of the fuel of the valve body 13 like this in the 1A is shown, is the injection port plate 25 arranged, which is formed with a thin disk-shaped shape. The 1A FIG. 12 illustrates a cross section cut in a folded manner so that the sectional shapes of the injection ports are understood. The injection connection plate 25 lies on the end side 13a of the valve body 13 on the downstream side of the fuel, and it is with the injection port plate 25 laser welded. In this injection connection plate 25 as it is in the 1B shown are four injection ports 25a . 25b . 25c and 25d formed, the fuel inlets on a common circle on a central axis 27 the injection port plate 25 exhibit. The injection connections 25a . 25b . 25c and 25d are in the force injection direction from the central axis 27 the injection port plate 25 formed spaced. The injection connections 25a . 25b . 25c and 25d are identical in terms of shapes and sizes and have equal sizes θ1, θ2 and θ3 as described below.

The injection connections 25a and 25b and the injection ports 25c and 25d are individually in the same directions with respect to the central axis 27 the injection port plate 25 educated. The injection direction of the injection ports 25a and 25b and the injection direction of the injection ports 25c and 25d are opposed by 180 °, so that the fuel injector 1 causes two injection directions.

The 4A shows a virtual plane which is an injection port axis 100 includes, which extends through the center of the fuel inlet and the center of the fuel outlet of the corresponding injection portion, and normal to the injection port plate 25 is, ie the section of the injection port plate 25 if he is along the line IV-IV according to the 3 is looked at. From cut lines between the virtual plane, the injection port axis 100 contains and orthogonal to the injection port plate 25 is, and an injection port inner circumference 101 the injection port plate 25 , which forms the injection port, it is assumed that a first cutting line 102 passing through the injection port axis 100 and the end side 26 is formed on the side of the fuel inlet, and located on the side of the obtuse angle, a first inclination angle θ1 with the central axis 27 forms, and that a second cutting line 103 passing through the injection port axis 100 and the end side 26 on the side of the fuel inlet of the injection port plate 25 is formed and located on the side of the acute angle, a second inclination angle θ2 with the central axis 27 forms. Under these assumptions, θ1 <θ2. In other words, at each injection port, the injection port inner circumference 101 if he is from the middle axis 27 the injection port plate 25 with regard to the injection connection axis 100 further away, in terms of the central axis 27 more inclined than that Injection port inner circumference 101 if he is from the middle axis 27 the injection port plate 25 with regard to the injection connection axis 100 less far away.

In the 4B showing a section showing the injection connection axis 100 and which is orthogonal to the cross section which is in the 4A is shown, the injection port extends as it were to the two sides. If θ3 = θ2 - θ1, and if the injection port has a diverging angle θ4, then θ4 ≤ θ3. As with an injection connection plate 110 a modification that in the 6 is shown, the injection port can in contrast diverge only to one side. If the injection port has a diverging angle θ5 in this case, then θ5 ≤ θ3 / 2.

In the 4A is a part of a closed curve of a cutting line between a virtual plane that is orthogonal to the injection port plate 100 is, and the injection port inner circumference 101 an ellipse 105 like this in the 5 is shown. A small diameter "a" and a large diameter "b" of the ellipse 105 are set so that 0.5 ≦ a / b ≦ 1 irrespective of the rotational position of the ellipse 105 applies.

At the downstream side of the fuel from a setting tube 34 like this in the 2 is shown is a spring 35 arranged to the nozzle needle 20 to the valve seat 14a pretension. By changing the axial position of the adjusting tube 34 can be the preload force of the spring 35 for biasing the nozzle needle 20 be set.

The sink 41 around the bobbin 40 is wound in the case 11 positioned them to the individual end portions of the stator core 30 and the magnetic tube 12 covering, which is transverse to the non-magnetic tube 32 are positioned, and the circumference of the non-magnetic tube 32 , The sink 41 is with a connection 42 electrically connected, so that one on the connection 42 applied electrical voltage in the coil 41 is fed.

An operation of the fuel injection valve 1 will be described below.

While the power to the coil 41 turned off, become the movable core 31 and the nozzle needle 20 to the valve seat 14a by the biasing force of the spring 35 moves so that the stopper section 21 to the valve seat 14a is set. Therefore, the fuel channel 50 closed so that the fuel is not injected from the individual injection ports.

When the power to the coil 41 is turned on, then is in the coil 41 generates an electromagnetic attraction, which is the movable iron core 31 to the stator core 30 can attract. If the movable core 31 to the stator core 30 is attracted by the electromagnetic attraction, then the nozzle needle 20 to the stator core 30 moves so that the stopper section 21 the valve seat 14a leaves. As a result, the fuel flows from the open portion between the stopper portion 21 and the valve seat 14a in the fuel chamber 51 , Thus, the fuel enters the fuel chamber 51 has flowed in, to the central portion of the fuel chamber 51 , The fuels flowing to the central portion collide at the central portion to form a radially outward flow that collides over the individual injection ports against the fuel flowing in a direction toward the central portion. The fuel flow that has collided via the corresponding injection port flows into the corresponding injection port. It is desirable that the fuel flow that has flowed into the injection port is along the injection port inner circumference 101 uniformly expanded to one direction, the injection port axis 100 cuts.

According to the present embodiment, "a" and "b" are regardless of the rotational position of the ellipse 105 is set so that 0.5 ≦ a / b ≦ 1. In contrast, if 0.5> a / b, then the ellipse becomes 105 oval, allowing the speed of the fuel, along the injection port inner circumference 101 flows to the direction that the injection port axis 100 cuts, according to the circumferential position of the ellipse 105 is changed greatly. When the velocity of the fuel flow is changed, the fuel that expands along the injection port inner circumference expands 101 flows to the direction that the injection port axis 100 incompletely along the injection port inner circumference 101 , Thus, no liquid fuel film having a uniform thickness is formed, whereby fuel atomization is deteriorated.

When "a" and "b" are set so that 0.5 ≤ a / b ≤ 1, and when the ellipse is prevented 105 becomes oval, then the fuel expands along the injection port inner circumference 101 to the direction that the injection port axis 100 cuts. Thus, the thickness of the liquid fuel film regardless of the circumferential position of the ellipse 105 uniformly. Since the thickness of the liquid fuel film is uniform and the fuel is injected like a funnel which spreads in an injection direction, the fuel atomization is improved. If further the ellipse 105 completeness, dig is round, then the injection port is formed by a conical punch, so that the injection port is formed in a simple manner and accurate.

Further, the injection port expands from a fuel inlet to a fuel outlet, and the first cut line 102 and the second cutting line 103 are with respect to the central axis 27 inclined in the same direction as the injection connection axis. Thus, the fuel that has collided over each injection port and flowed into the injection port flows to an injection outlet port as shown in FIG 7 as shown along the injection port inner circumference 101 expanded. The fuel flows from the injection port inlet to the injection port outlet while passing along the injection port inner circumference 101 uniformly expanded, it becomes a liquid fuel film having a uniform thickness, and it is injected from the injection port. Since the fuel is injected as a liquid film rather than a liquid column, it has a uniform thickness like the funnel which spreads to the injection direction, and the fuel is easily atomized.

in this connection become the desired Design values of the fuel injector described for atomization of the Fuel sprays are set.

The distance from the intersection between the second cut line 103 and the end side 26 on the side of the fuel inlet to the first cutting line 102 ie, an injection port diameter d, and a distance h between the front end side 20a the nozzle needle 20 opposite the end side 26 at the side of the fuel inlet at the stroke time of the nozzle needle 20 and the end side 26 on the side of the fuel inlet are set so that the following relationship (1) is satisfied: h <1.5d (1).

Setting the distance h and the injection port diameter d such that they satisfy the relation (1) is established. If the nozzle needle 20 the inner circumference 14 of the valve body 13 leaves, then the fuel passes into the space between the stopper portion 21 and the inner circumference 14 to the injection port plate 25 continues, and the fuel flow is to the fuel chamber 51 deflected when they are against the end side 26 on the side of the fuel inlet of the injection port plate 25 collides, allowing a fuel flow along the end side 26 is formed on the side of the fuel inlet. This fuel flow is divided into a flow directly to the injection port and into a flow passing between the injection ports, so that the flow that has passed between the injection ports, U-shaped to the injection port through the counterflow at the center of the injection port plate 25 is diverted. These fuel flows, which are directed to the injection port in the radially opposite directions, collide directly above the injection port, so that they interfere and promote the atomization of the fuel.

A normal distance h from the annular seat portion of the valve seat 14a to which the nozzle needle 29 is set to the end side 26 on the side of the fuel inlet of the injection port plate 25 and the injection port diameter d are set to satisfy the following relationship (2): H <4d (2).

In short, the valve seat 14a when at the inlet of the fuel to the fuel chamber 15 is positioned near the injection port plate 25 arranged. The inner circumference 14 converges downstream of the fuel, and the normal distance h between the valve seat 14a and the end side 26 at the side of the fuel inlet and the injection port diameter d are set so that the relationship (2) is satisfied. If the nozzle needle 20 and the valve body 13 spaced from each other, then the fuel, between the stopper portion 21 and the valve seat 14a along the inner circumference 14 in the fuel chamber 51 should flow along the end side 26 on the side of the fuel inlet.

On the other hand, the diameter DH of a circumference extending through the fuel inlets of the injection ports and the seat diameter Ds of the nozzle needle 20 attached to the valve seat 14a is set so that the following relationships (3) are satisfied: 1.5 <Ds / Dh <6 (3).

If the nozzle needle 20 and the valve body 13 spaced from each other, then the fuel flows between the stopper portion 21 and the valve seat 14 in the fuel chamber 51 should flow along the inner circumference 14 , and then he walks, after which he passes through the end page 26 on the side of the fuel inlet of the injection port plate 25 deflected while not flowing directly into the injection ports, over a predetermined distance between the end side 26 on the side of the fuel inlet and the front end side 20a continued. As a result, the main flow of the fuel does not enter directly into the injection ports, so that the fuel in an effective Wei can be atomized. If the relationships (3) are satisfied, then the injection ports can be arranged within a range that is neither excessively close to the center of the injection port plate 25 is still arranged excessively to the outer peripheral side of the injection port plate 25 diverges. Therefore, the intensities of the fuel flows in the individual injection ports can be substantially homogenized, regardless of the inflow directions. As a result, the internal energy of the fuel can be effectively utilized in the form of disturbances caused by the collisions of the flows themselves, so that a remarkably ideal atomization can be realized. In addition, the homogeneous collisions at the inlet center of the injection port can be achieved so that the atomization with excellent directionality along the inclination of the Einspritzanschlussinnnenumfangs 101 can be established, which forms the injection ports.

• (a) θ3 = 24°, und t/d = 0,67. Falls der Wert von θ1 verändert wird, dann beträgt die Partikelgröße ungefähr 85 Mikrometer oder weniger innerhalb des Bereiches von θ1 ≥ 15°. Für einen größeren θ1 wird der Kraftstoff, der zu dem Einspritzanschlussinnenumfang 101 zu führen ist, der die erste Schnittlinie 102 enthält, so gespreizt, dass das Kraftstoffspray in einfacher Weise zerstäubt wird.
• (b) θ1 = 36°, und t/d = 0,67. Falls der Wert von θ3 verändert wird, dann beträgt die Partikelgröße ungefähr 85 Mikrometer oder weniger. Für einen größeren θ3 wird die Fläche des Einspritzanschlussinnenumfangs 101 vergrößert. Daher wird der Kraftstoff so gespreizt, dass das Kraftstoffspray in einfacher Weise zerstäubt wird.
• (c) θ1 = 36° und θ3 = 24°. Falls der Wert von t/d verändert wird, wie dies in der 8C gezeigt ist, dann beträgt die Partikelgröße ungefähr 85 Mikrometer oder weniger für einen Bereich von 0,5 ≤ t/d ≤ 1,2. Falls 0,5 ≥ t/d gilt, dann wird die Richtung des Kraftstoffsprays, der aus dem Einspritzanschluss einzuspritzen ist, zwar dispergiert, aber sie wird nicht stabilisiert. Falls t/d > 1,2 gilt, dann haften die Kraftstoffe, die durch die Einspritzanschlüsse hindurch treten, so aneinander, dass der homogene Film nicht erzeugt wird, so dass die Zerstäubung des Kraftstoffsprays behindert wird. Kurz gesagt, durch das Aufrechterhalten der Beziehungen von 0,5 ≤ t/d ≤ 1,2 ist es möglich, den Kraftstoff in einer vorbestimmten Richtung einzuspritzen und das Kraftstoffspray ausreichend zu zerstäuben.

Here, the ranges of θ1, θ3 and t / d are specified if the injection port plate 25 has a thickness t and if the desired fuel spray has a particle size of about 85 microns or less.

• (a) θ3 = 24 °, and t / d = 0.67. If the value of θ1 is changed, then the particle size is about 85 microns or less within the range of θ1 ≥ 15 °. For a larger θ1, the fuel going to the injection port inner periphery becomes 101 to lead is the first cut line 102 contains, so spread that the fuel spray is atomized in a simple manner.
• (b) θ1 = 36 °, and t / d = 0.67. If the value of θ3 is changed, then the particle size is about 85 microns or less. For a larger θ3, the area of the injection port inner circumference becomes 101 increased. Therefore, the fuel is spread so that the fuel spray is easily atomized.
• (c) θ1 = 36 ° and θ3 = 24 °. If the value of t / d is changed, as in the 8C is shown, the particle size is about 85 micrometers or less for a range of 0.5 ≦ t / d ≦ 1.2. If 0.5 ≥ t / d, then the direction of the fuel spray to be injected from the injection port is dispersed, but it is not stabilized. If t / d> 1.2, then the fuels that pass through the injection ports adhere to each other so that the homogeneous film is not generated, so that the atomization of the fuel spray is hindered. In short, by maintaining the relationships of 0.5 ≦ t / d ≦ 1.2, it is possible to inject the fuel in a predetermined direction and to sufficiently atomize the fuel spray.

Around the individual characteristics of the three parameters θ1, θ3 and t / d for the atomization fuel spray fixed the remaining two parameter values. However, these must remaining two parameters not to the above-mentioned values be fixed, but the atomization The fuel spray can be conveyed better if θ1 ≥ 15 °, θ3 ≥ 15 ° or 0.5 ≤ t / d ≤ 1.2.

The four injection ports were in the first embodiment trained, but their number can be other than four, to Example only one as long as θ1 <θ2 is satisfied.

Second Embodiment

A fuel injection nozzle according to a second embodiment of the invention is in the 9A and 9B shown. The construction portions that are substantially the same as the first embodiment will not be described, and will be denoted by common reference numerals. The 9A represents a folded section for a better understanding of the sectional shape of the injection ports.

Like this in the 9B are shown in an injection port plate 60 twelve injection connections 60a . 60b . 60c . 60d . 60e . 60f . 60g . 60h . 60i . 60j . 60k and 60m educated. The injection connections 60a . 60b . 60c and 60d are disposed at their fuel inlets on the circumference of the inner peripheral side, and the injection ports 60e . 60f . 60g . 60h . 60i . 60j . 60k and 60m are disposed at their fuel inlets at the periphery on the outer peripheral side. The direction of the injection connections 60a . 60b . 60e . 60f . 60g and 60h for injecting the fuel is 180 ° to the direction of the injection ports 60c . 60d . 60i . 60j . 60k and 60m opposed, so as to inject the fuel so that two injection directions are realized. In each injection port, the relationships between θ1, θ2 and θ3 are identical to the first embodiment.

There the fuel injection rates are the same as in the first embodiment can be lowered, the injection rate per injection port, so that the injection port diameter is reduced so that the atomization promoted the fuel spray becomes.

(Third Embodiment)

A fuel injection nozzle according to a third embodiment of the invention is shown in FIGS 10 shown. The structure of the third embodiment is substantially identical to the first embodiment, except that a nozzle needle 65 of the third embodiment on its front end side 65a so rounded is that a valve body 66 has a slightly changed shape, which corresponds to the shape of the front end side 65a fits. A fuel chamber 67 is not formed with the flat disc-shaped shape. However, by forming the injection port having the same shape and size as the first embodiment, the fuel is injected as a liquid film so that the fuel spray is atomized.

(Fourth Embodiment)

A fuel injection nozzle according to a fourth embodiment of the invention is shown in FIGS 11A and 11B shown. The construction portions that are substantially the same as the first embodiment will not be described, and will be denoted by common reference numerals. The 11A represents a folded section for a better understanding of the sectional shape of the injection ports.

Like this one of the 9A is shown is a recess 71 at the downstream end side portion of the fuel from a valve body 70 educated. An injection connection plate 80 is formed with a thin disc-shaped shape, and it is at an end portion 70a on the downstream side of the fuel from the valve body 70 arranged. A stop section 76 holding a nozzle needle 75 is formed, can be attached to the valve seat 14a be set. At the end portion on the downstream side of the fuel from the abutment portion 76 is a bulge 77 formed to the injection port plate 80 is overgrown. The nozzle needle 75 at the front end of the bulge 77 is formed is on its front end side 75a flattened.

A fuel chamber 90 passing through the recess 71 and the injection port plate 80 is divided as a fluid chamber is formed with a flat disc-shaped shape, and has a larger diameter than an opening edge 14b on the downstream side of the fuel or as an opening edge on the downstream side of the fluid from the inner periphery 14 , Like this in the 11B are shown are internal injection ports 80a . 80b . 80c and 80d on the inner perimeter side of a virtual shell 200 formed at the the virtual level of the inner circumference 14 which extends to the downstream side of the fuel, the end side 81 on the side of the fuel inlet from the injection port plate 80 cuts, and external injection ports 80e . 80f . 80g . 80h . 80i . 80j . 80k and 80m are on the outer peripheral side of the virtual shell 200 educated. The direction for the inner injection connections 80a and 80b and for the outer injection ports 80e . 80f . 80g and 80h are 180 ° from the direction for the inner injection ports 80c and 80d and for the outer injection ports 80i . 80j . 80k and 80m opposed, so that two-way injections are realized. The shapes and sizes of the individual injection ports are identical, and in each injection port, the relationships between θ1, θ2, and θ3 are identical to the first embodiment.

The internal injection connections 80a . 80b . 80c and 80d are positioned at their fuel inlets at a common circumference, which is assumed to have a diameter DH1. The outer injection connections 80e . 80f . 80g . 80h . 80i . 80j . 80k and 80m are positioned at their fuel inlets at a common circumference, which is assumed to have a diameter DH2. Between Ds, DH1 and DH2 the following relationships apply (4): 1.5 <Ds / DH1 <6; and 0.5 <Ds / DH2 <2 (4).

The fuel, along the inner circumference 14 to the injection port plate 80 should flow, colliding against the injection port plate 80 so that he is in the flow along the injection port plate 80 from the virtual shell 200 to the inner periphery and into the flow along the injection port plate 80 from the virtual shell 200 is divided to the outer circumference. The fuels entering the internal injection ports 80a and 80b and into the outer injection ports 80e . 80f . 80g and 80h to flow in those directions which are opposed to each other, and the fuels flowing into the internal injection ports 80c and 80d and into the outer injection ports 80i . 80j . 80k and 80m to flow in those directions that are opposed to each other. As a result, the fuels to be injected from the inner injection ports and the outer injection ports forming the individual sprays in the two directions are prevented from colliding with each other directly below the injection ports to promote the atomization of the fuel sprays.

In addition, the following relationships (5) between the distance h1 between the front end side apply 75a the nozzle needle 75 and the end side 81 on the side of the fuel inlet, the distance h2 between the bottom side 71a the recess 71 and the end side 81 at the fuel inlet side, and the injection port diameter d: h1 ≤ h2 <1.5 d (5).

If the relations (5) are fulfilled, if the nozzle needle 75 then raises the fuel that enters the fuel chamber 90 should flow, so led that he along the end side 81 on the side of the fuel inlet through the front end side 75a the nozzle needle 75 flows.

In the fourth embodiment, the bulge 77 at the front end of the nozzle needle 75 designed so that the capacity of the fuel chamber 90 is reduced while the valve is closed, while the stopper section 76 to the valve seat 14a is set. The ratio of the injection rate of the fuel in the fuel chamber 90 through the closed valve, to the total fuel injection rate is lowered so that the fuel injection rate can be controlled very accurately.

In the fourth embodiment, the fuel chamber 90 formed by the recess 71 at the end portion on the downstream side of the fuel from the valve body 70 is trained. In contrast, a structure may be adopted in which a disk-shaped fuel chamber is formed by forming the recess on the fuel inlet side of the injection port plate.

(Fifth Embodiment)

The 12A and 12B show a fuel injection nozzle in the fifth embodiment of the present invention. The 12A represents a folded section for a better understanding of the sectional shape of the injection ports.

Like this in the 12A is shown is a nozzle needle 115 in a valve body 110 while she can move around in it. Like this in the 12B shown are 12 injection ports 120a . 120b . 120c . 120d . 120e . 120f . 120g . 120h . 120i . 120j . 120k . 120m in an injection connection plate 120 educated. Arrangements of injection ports 120a . 120b . 120c . 120d . 120e . 120f . 120g . 120h . 120i . 120j . 120k . 120m are substantially the same as in the second embodiment, and the relationships between θ1, θ2, θ3 in each injection port are the same as in the first embodiment.

Like this in the 12A Shown are the sections in which the injection ports 120a . 120b . 120c . 120d . 120e . 120f . 120g . 120h . 120i . 120j . 120k . 120m are formed concave to the side of the fuel injection. Since the injection ports have been formed in advance in the planar injection port plate, and the portions where the injection ports are formed are concaved to the fuel injection side, the inclination angles of the injection ports formed in the flat injection port plate can be reduced. Since the inclination angles are small, the injection ports are easily formed.

at The many embodiments described above, the modes of operation of the invention, as far as they are described, have been the desired Design values for the fuel injector for atomising represented the fuel spray. If it is determined that at least θ1 <θ2, However, the fuel is guided so that it spreads through the injection port inner circumference and that he is considered the liquid Film is injected so that the fuel spray will be atomized can.

at In the many embodiments described above, the fuel injection nozzle of the invention used as the fuel injection valve of the gasoline engine. additionally can the fuel injector the invention for Any applications used, if necessary for sputtering and Injecting the liquid is intended.

(Sixth Embodiment)

The 14 to 19 show a sixth embodiment, which is not according to the present invention. The 14 shows a view of the overall structure of an electromagnetic fuel injection valve, and the 15 shows a view of an essential structure of the electromagnetic fuel injection valve.

An electronically controlled fuel injection system of this embodiment is configured to include a fuel supply system, an intake system, sensors for detecting the running conditions of the internal combustion engine, and an electronic control unit (ECU) for integrally controlling them. The fuel supply system is a system that allows an electric fuel pump (although not shown) to pressurize the fuel to a predetermined pressure, and fuel via a delivery pipe (though not shown) to an electromagnetic fuel injection valve 301 supplied so that the fuel can be injected at an optimal timing.

The electromagnetic fuel injection valve 301 is a fuel injection device having a function (or an orifice plate) for promoting atomization of sprayed fuel, which at good timing in the vicinity (or in the inlet port) of an intake valve (or a suction valve) of an internal combustion engine (This will be hereinafter referred to as the "engine"), such as a gasoline engine, and the electromagnetic fuel injection valve 301 mounted with an intake manifold (or with an intake pipe) provided in a number corresponding to the number of cylinders of the engine to supply the air for combustion.

The electromagnetic fuel injection valve 301 is constructed to include: a cast housing 302 to be mounted with the conveyor pipe; an electromagnetic coil (solenoid coil) 304 around the outer circumference of a bobbin reel 303 wound, which is formed of a synthetic resin, and in the cast housing 302 is arranged; a generally cylindrical stator core 305 in the cast housing 302 is attached; an anchor 306 which is axially movable; a valve body 307 located at the front end side of the cast housing 302 is arranged; a needle valve 308 that in the valve body 307 is housed; and an orifice plate 310 to a fuel channel 309 between itself and an axial end side (or front end side) of the needle valve 308 train.

The cast housing 302 is integrally molded from a synthetic resin material. In this cast housing 302 are the bobbin reel 303 , the stator core 305 and an outer connector 311 cast in one piece. To the bobbin reel 303 and the electromagnetic coil 304 is also a synthetic resin molding 335 integrally potted, which is the electromagnetic coil 304 envelops.

In the illustrated upper section of the cast housing 302 on the other hand is a plug unit 312 arranged by the outer wall of the cast housing 302 protrudes. In addition, the outer plug connection 311 that with the electromagnetic coil 304 is to be electrically connected, in the plug unit 312 and a synthetic resin molding 336 embedded. On the other hand, the outer plug connection 311 connected to the ECU, not shown, via a wiring.

The stator core 305 is made of a ferromagnetic material, and it is so in the resin housing 302 arranged that it from the shown upper end side of the cast housing 302 protrudes upward. In the stator core 305 is also an axial fuel channel 313 educated. In the inner circumference of the stator core 305 is a generally cylindrical adjusting tube 315 fitted, which is an axial hole 314 having.

The adjusting tube 315 sets a specified load, ie, a valve opening pressure of a coil spring 306 in which it is in the axial direction in the stator core 305 is moved and fastened, after which it is in the inner circumference of the stator core 305 was determined. At the front end side of the adjusting tube 315 is also one end of the coil spring 316 at. The other end of this coil spring 316 is located on the shown upper end side of the needle valve 308 to the anchor 396 welded and attached.

The coil spring 316 tenses the anchor 306 and the needle valve 308 downwards, as shown, around a seat portion 322 of the needle valve 308 to a valve seat 321 of the valve body 307 to set (referring to the 15 ). When an exciting current from the outer plug portion 311 into the electromagnetic coil 304 fed by the ECU becomes the anchor 306 and the needle valve 308 also to the stator core 305 against the biasing force (or spring force) of the coil spring 316 dressed.

On one axial side of the stator core 305 on the other hand are a non-magnetic tube 317 and a magnetic tube 318 arranged. The non-magnetic tube 317 It is made of a non-magnetic material and is formed in a generally cylindrical shape. This non-magnetic tube 317 is with the lower end of the stator core shown 305 connected. On the other hand, there is the magnetic tube 318 made of a magnetic material, and it is formed with a stepped tubular shape. This magnetic tube 318 is with the bottom end of the non-magnetic tube shown 317 connected. In the interiors of this non-magnetic tube 317 and this magnetic tube 318 is the anchor 306 fitted, which consists of a magnetic material and is formed with a cylindrical shape.

Into the magnetic tube 318 is also through a hollow disk-shaped spacer 319 the valve body 307 inserted, which is laser welded thereto. The thickness of the spacer 319 is set so that the air gap between the stationary iron core 305 and the movable iron core 306 is kept at a predetermined value. Here are the cast housing 302 , the electromagnetic coil 304 , the stator core 305 , the anchor 6 that is not magnetic tube 317 , the magnetic tube 318 and the like constructed as an electromagnetic actuator.

Here are the structures of the valve body 307 and the needle valve 308 of the present embodiment with reference to FIGS 14 and 15 briefly described. This valve body 307 and this needle valve 308 are formed of a metallic material such as SUS having a predetermined shape. Between the cylindrical plane 323 of the valve body 307 and the four-sided section, which is on a sliding section 324 of the needle valve 308 is formed, also a gap is formed so that the fuel passes through there. In addition, form the valve seat 321 of the valve body 307 and the seat section 322 at the front end of the needle valve 308 a valve unit.

The needle valve 308 corresponds to a valve element, and it forms a joint section 325 in the upper section shown. In addition, this joining section 325 and the anchor 306 laser welded, leaving the anchor 306 and the needle valve 308 are integrally connected. The joining section 325 is provided at its outer periphery for a fuel passage with a phase. On the other hand, the needle valve 308 raised as far as the anchor 306 through the stator core 305 is attracted by a magnetomotive force in the electromagnetic coil 304 is generated, which is a flange 326 in contact with the spacer 319 arrives. Hereby form the valve body 307 and the orifice plate 310 the valve main body of the electromagnetic fuel injection valve 301 , and the needle valve 308 forms the valve element of the electromagnetic fuel injection valve 301 ,

In the shown upper section of the fuel channel 313 in the stator core 305 is formed, on the other hand, a filter 337 fitted. This filter 337 is a means for cleaning foreign matter for cleaning the fuel when it is discharged from the fuel tank into the electromagnetic fuel injection valve 301 is pumped by the fuel pump or the like, and foreign matter, such as dust.

Here, the structure of the orifice plate 310 of this embodiment with reference to FIGS 14 to 19 briefly described. The 16 shows a representation of the channel wall side of the orifice plate 310 , and the 17 shows an enlarged view of the vicinity of a fuel inlet of the orifice plate 310 ,

The orifice plate 310 corresponds to an injection port plate, and it is so on the front end side of the valve body by the laser welding 307 attached that a round opening 329 is closed, which at the shown lower end side (or the front end side) of the valve body 307 is trained. This orifice plate 310 consists of a metallic material such as SUS. In the opening plate 310 is also a variety of openings 330 designed to control the directions of the fuel spray and to promote the atomization of the fuel spray.

These openings 330 correspond to injection ports, and they are formed by spark erosion or drilling, for example, so that four openings on an imaginary circle on the center axis of the orifice plate 310 to be ordered. The variety of openings 330 is through the orifice plate 310 from the fuel inlet to the fuel outlet of the openings 330 is formed to be at a predetermined angle A (degree) to the upstream side with respect to the fuel flow direction of the fuel passage 309 tilted backwards. In the connecting walls of the many openings 330 from the fuel inlets to the fuel outlets are also two first and second curved circular sections 331 and 332 formed, the centers of curvature at the central axis 333 the opening 330 and to the upstream side with respect to the fuel flow direction of the fuel passage 309 are directed to the rear.

The first curved circle section 331 is located on the side of the central axis (in the center direction of the injection valve) of the electromagnetic fuel injection valve 301 the two first and second curved sections of the circle 331 and 332 , This first curved circle section 331 has a predetermined radius of curvature having its center (C1) of a curvature located at the center of the curved circle. On the other hand, there is the second curved circle section 332 on the side opposite to the center axis (in the seating direction) of the electromagnetic fuel injection valve 301 the two first and second curved sections of the circle 331 and 332 , This second curved circle section 332 has a predetermined radius of curvature having its center (C2) of a curvature located at the center of curvature of the circle. The radius of curvature of the first curved circle section 331 and the radius of curvature of the second curved circle section 332 are the same (for example, an injection port diameter φd / 2).

In addition, the shape of the opening fulfills 330 following relations 0 (mm) <L <2R (mm), if an offset between the means (C1) of the curvature of the first curved circle section 331 and the center (C2) of the curvature of the second curved circle section 332 by L (mm), and if the second curved circle section 332 has a radius R (Φd / 2) of the curvature. On the other hand, the inclination angle A (degrees) satisfies the opening 330 regarding the thick direction of the orifice plate 310 the following relationships 0 <A <90 °. Here, in the electromagnetic fuel injection valve 301 of this embodiment, the relationship between the thickness t (mm) and the injection port diameter φd (mm) is set within a predetermined range so as to promote a predetermined function of maintaining the atomization. Hereby be marks a reference numeral 334 a liquid column section which is in the flow of the fuel in the opening 330 is to produce.

An operation of the electromagnetic fuel injection valve 301 of the present embodiment will be described with reference to FIGS 14 to 19 briefly described.

When the electromagnetic coil 304 the electromagnetic fuel injection valve 301 is excited by the ECU, then the movable iron core 306 through the stator core 305 against the biasing force of the coil spring 316 tightened, leaving the needle valve 308 with the joining section 325 who is at the anchor 306 Laser welded, is raised so far that the flange section 326 in contact with the spacer 319 arrives. Then the valve unit is opened out of the valve seat 321 of the valve body 307 and the seat portion 322 of the needle valve 308 consists.

As a result, when the fuel is pressurized to a predetermined pressure by the fuel pump, it flows through the delivery pipe and the filter 337 in the fuel channel 313 in the stationary iron core 305 the electromagnetic fuel injection valve 301 is trained. The fuel exits the axial hole 314 that in the adjusting tube 315 is formed, through the gap of a two-sided beveled portion, which at the joining portion 325 of the needle valve 308 is formed, and further through the gap between the cylindrical side 323 of the valve body 307 and the four-sided chamfered portion attached to the sliding portion 324 of the needle valve 308 is formed until it is the interior of the fuel channel 309 between the valve seat 321 of the valve body 307 and the seat portion 322 of the needle valve 308 reached.

Also, the main flow of fuel that collides between the valve seat collides 321 and the seat section 322 has passed through, in the fuel channel 309 against the duct wall side of the orifice plate 310 like this in the 19A is shown, so that he along the channel wall side of the orifice plate 310 and to the center axis of the electromagnetic fuel injection valve 301 emigrated. In addition, the main flow of fuel migrates out of the fuel passage 309 into the fuel inlet of the opening 330 from the interior of the fuel channel 309 without any whirl around the fuel inlet of the opening 330 like this in the 19A is shown while it to the channel wall side of the first curved circular section 331 the opening 330 is diverted.

Like this in the 19A and 19B is shown doing so in the flow of fuel in the opening 330 the liquid column section 334 generated along a section 331 from the first and second curved segments of the circle 331 and 332 is dispersed, which is located on the side of the central axis (in the center direction of the injection valve) of the electromagnetic fuel injection valve 301 is located so that the fuel at a good timing from the fuel outlet of the opening 330 is injected to the vicinity of the intake valve of the engine.

In the electromagnetic fuel injection valve 301 of the present embodiment already described becomes the liquid column section 334 the flow of fuel in the opening 330 enlarged on the surface to increase its contact area with the air, so that the splitting of the liquid column section 334 the fuel flow in the opening 330 is encouraged. Therefore, the fuel flow can be effectively utilized to realize significantly improved atomization.

(Seventh Embodiment)

The 20 and 21 show a seventh embodiment, which is not in accordance with the present invention. The 20 FIG. 11 is a view showing an essential structure of an electromagnetic fuel injection valve, and FIGS 21 shows a view of a channel wall side of an orifice plate.

As with the many openings 330 of this embodiment are 12 openings on imaginary double circles on the center axis of the orifice plate 310 arranged. These openings 330 are through the orifice plate 310 from their fuel inlets to their fuel outlets are formed to be at a predetermined angle to the upstream side in the fuel flow direction of the fuel passage 309 tilted backwards.

In the connection wall sides of the many openings 330 from the fuel inlets to the fuel outlets are also individually the two first and second curved circular sections 331 and 332 formed, which are the centers of curvature at the central axis 333 the openings 330 and that from the center axis of the electromagnetic fuel injection valve 301 as in the first embodiment directed backwards (to the seat). Here are the many openings 330 be freely arranged within a range that does not deteriorate the effect of promoting the atomization of the fuel spray.

(Modifications)

The present embodiments have been described as examples in which the Fuel injection valve for the internal combustion engine, such as the electromagnetic fuel injection valve (fuel injector) 301 is attached to the intake manifold of the gasoline engine. However, the fuel injection valve for the internal combustion engine may be attached to the cylinder of the engine, or the fuel injection valve may be attached to a combustor such as a boiler or a petroleum stove.

The present embodiments have been described as examples related to the electromagnetic fuel injection valve 301 be applied, in which the valve element such as the needle valve 308 is arranged to be movable back and forth in the axial direction by the electromagnetic actuator. However, these embodiments may be applied to the fuel injection valve in which the valve element is mechanically reciprocated in the axial direction. For example, these embodiments may be applied to the fuel injection nozzle having a valve element which is opened when the fuel is supplied so as to reach a predetermined hydraulic force.

Claims (8)

Fluid injection nozzle ( 1 ) with: a valve body ( 13 ) with an inner circumference ( 14 ), which has a fluid channel ( 50 ) and converges to a downstream side of the fluid, and the one valve seat ( 14a ) on the inner circumference ( 14 ) having; an injection connection plate ( 25 ) located on the fluid channel on the downstream side of the valve seat (FIG. 14a ) and an injection port ( 25a to 25d ) for injecting a fluid to escape from the fluid channel ( 50 ), wherein an injection connection axis ( 100 ) having a center of a fluid inlet and a center of a fluid outlet of the injection port ( 25a to 25d ) connects, with respect to a central axis ( 27 ) of the injection port plate ( 25 ) is inclined, wherein the fluid injection nozzle ( 1 ) a plurality of injection ports ( 25a to 25d ) and each injection port axis ( 100 ) with respect to the central axis ( 27 ) of the injection port plate ( 25 ) is inclined outwardly from the upstream side to the downstream side so that the injection connection axes ( 100 ) on the downstream side of the injection port plate do not intersect with each other; and a valve element ( 20 ) for closing the fluid channel ( 50 ), when it is on the valve seat ( 14a ) and to open the fluid channel ( 50 ), if it is not on the valve seat ( 14a ), wherein two lines of intersection between a virtual plane containing the injection connection axis ( 100 ) and normal to the injection port plate ( 25 ) and an injection port inner circumference ( 101 ) of the injection port plate ( 25 ), the injection port ( 25a to 25d ), in the same direction as the injection connection axis ( 100 ) with respect to the central axis ( 27 ) and when a first cut line ( 102 ), which on one side of an obtuse angle through the injection connection axis ( 100 ) and an end page ( 26 ) at the fluid inlet side of the injection port plate ( 25 ), a first inclination angle θ1 with respect to the central axis ( 27 ) and if a second cut line ( 103 ), which on one side of an acute angle through the injection connection axis ( 100 ) and the end side ( 26 ) at the fluid inlet side has a second inclination angle θ2, then θ1 <θ2, characterized in that the inner diameter of the injection ports ( 25a to 25d ) increases evenly from the fluid inlet to the fluid outlet. Fluid injection nozzle ( 1 ) according to claim 1, wherein θ1 is 15 ° or larger. Fluid injection nozzle ( 1 ) according to claim 1, wherein θ3 = θ2 - θ1 and θ3 ≥ 15 °. Fluid injection nozzle ( 1 ) according to claim 1, wherein when the distance from an intersection between the second cutting line ( 103 ) and the end side ( 81 ) on the side of the fluid inlet to the first cutting line ( 102 ) is denoted by d, and when the injection port plate ( 25 ) has a thickness t, then the following relationship holds: 0.5 ≤ t / d ≤ 1.2. Fluid injection nozzle ( 1 ) according to claim 1, wherein in a plane in which a cut line between a virtual plane perpendicular to the injection port axis ( 100 ), and the injection port inner circumference ( 101 ) is an ellipse, wherein a diameter of a minor axis of the ellipse is "a" and a diameter of a major axis is "b", the following relationship holds: 0.5 ≤ a / b ≤ 1. Fluid injection nozzle ( 1 ) according to claim 1, wherein in a group of injection ports ( 25a to 25d ) around the central axis ( 27 ) and their fluid inlets have at a common circumference, wherein the circumference has a diameter DH, wherein the valve element ( 20 ) connected to the valve seat ( 14a ), having a seat diameter Ds, wherein a normal distance from a ring-like seat portion of the valve seat ( 14a ), to the the valve element ( 20 ), to the end side ( 81 ) at the side of the fluid inlet is denoted by H, and wherein a distance between a front end side (FIG. 20a ) of the valve element ( 20 ) opposite the end side ( 81 ) on the side of the fluid inlet and the end side ( 81 ) on the side of the fluid inlet at the stroke time of the valve element ( 20 ) is denoted by h, at the same time the following relations apply: 1.5 ≤ Ds / DH 6, and h <1.5 d; and H <4d the distance from an intersection between the second cutting line ( 103 ) and the end side ( 81 ) on the side of the fluid inlet to the first cutting line ( 102 ) is denoted by d, and wherein the injection port plate ( 25 ) has a thickness t, in which case the following relationship applies: 0.5 ≤ t / d ≤ 1.2. Fluid injection nozzle ( 1 ) according to claim 1, wherein a fluid chamber ( 51 ) directly above the side of the fluid inlet of the injection port ( 80a to 80k . 80m ) is diametrically larger than a downstream opening edge formed by the inner periphery, and the injection ports ( 80a to 80k . 80m ) at its fluid inlet in the inner periphery and the outer periphery of a virtual shell ( 200 ), at which the virtual plane extending from the inner periphery to the downstream side, the injection port plate ( 80 ) cuts. Fluid injection nozzle ( 1 ) according to claim 7, wherein a group of injection ports ( 80a to 80k . 80m ) around the central axis ( 27 ) are distributed and their fluid inlets at a common circumference, wherein the circumference of the injection port group, on the inner peripheral side of the virtual shell ( 200 ), and having the diameter of the injection port group, which on the outer peripheral side of the virtual shell ( 200 ), has a diameter DH2, at the same time the following relationships apply: 1.5 ≤ Ds / DH1 6, and 0.5 <DH2 <2 where Ds is the seat diameter when the valve element ( 20 ) to the valve seat ( 14a ) is set.