JP2000038975A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply realize the structure of a fuel injection valve capable of efficiently atomizing fuel by the less amount of air flow, and apply the aforesaid fuel injection valve to an engine of a type having plural intake valves per cylinder. SOLUTION: A fuel passage is opened/closed by means of valve element 8 to be electromagnetically driven. Fuel nozzles 5 are formed up at the downstream of the fuel passage, and a thin plate provided with the plural number of holes is disposed to the downstream of the aforesaid nozzle. Fuel atomization is accelerated by letting air injected out of plural air nozzles 2A be hit collide with fuel injected through the aforesaid thin plate, and furthermore, fuel is branched to the plural number of directions by a member 7 provided for the down-stream of the air nozzles 2A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel injection valve in an engine.

[0002]

2. Description of the Related Art Conventionally, in the field of gasoline engines such as automobiles, a fuel injection valve (for example, a solenoid valve) is operated by an electric signal.
Is driven to inject fuel into the intake passage.

In this type of fuel injection valve, in order to atomize the fuel, the fuel is swirled to form a thin film and injected, or air is introduced into the nozzle body of the fuel injection valve to inject the air flow. Means such as merging with later swirling fuel have been proposed (for example, Japanese Patent Application Laid-Open Nos. 57-183559 and 64-241).
No. 61).

[0004]

In the case where the swirl fuel injected as described above is atomized by an air flow, no consideration has been given to reducing the amount of atomizing air guided to the nozzle body. In particular, when the fuel amount is small as in the idling operation, the air for atomization tends to be relatively large, and accordingly, the air passing through the throttle valve in the intake passage must be extremely reduced.

[0005] To reduce the clearance area of the throttle valve,
The precision of the throttle valve must be further improved, which is practically difficult.

Further, since the speed of the particle diameter of the spray injected from the injection valve is as large as about 20 m / s, the injected fuel is
Since it adheres to the intake pipe wall or the intake valve to form a liquid film, there is a problem that the effect of improving atomization is difficult to obtain.

SUMMARY OF THE INVENTION It is an object of the present invention to achieve efficient atomization of fuel with a small air flow rate, to easily realize the structure of such a fuel injection valve, and to provide such a fuel injection valve with one fuel injection valve. An object of the present invention is to apply the present invention to an engine of a type having a plurality of intake valves per cylinder.

[0008]

In order to achieve the above object, the present invention basically proposes the following means for solving the problems. In order to facilitate understanding of the contents, a description will be given with reference to some of the drawings used in the description of the embodiments and reference numerals used in the drawings.

As shown in FIG. 21, for example, an electromagnetic fuel injection valve according to the present invention comprises a valve element 8 driven electromagnetically and a fuel passage opened and closed by the valve body 8 (part of the fuel passage in the figure). 6A), a fuel nozzle 5 formed downstream of the fuel passage 6A, and a plurality of holes (for example, 5
-1, 5-2), and a plurality of air nozzles 2A for introducing air to impinge on fuel injected through the thin plate 21 and the thin plate 21 disposed downstream of the fuel nozzle 5.
And a member 7 arranged downstream of the air nozzle 2A to branch the fuel into a plurality of fuels.

According to the above construction, when the fuel passage 6A is opened by the valve body 8 which is electromagnetically driven, the fuel ejected from the fuel nozzle 5 causes the plurality of holes 5-1 and 5-1 of the thin plate 21 to be located immediately downstream. 5-2, the fuel is atomized by colliding with the air injected from the plurality of air nozzles 2A, and the fuel is further reduced by the member 7 provided downstream of the air nozzle 2A. Divided into multiple directions.

Further, a plurality of fuel nozzles (holes) 5-1 and 5 are provided.
Since the nozzle body -2 is formed by the thin plate 21 separate from the nozzle body 2, the structure of the nozzle body 2 can be simplified, and the molding can be easily performed.

[0012]

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

FIG. 1 is a sectional view of a main part showing a first embodiment of the present invention, and FIG. 2 is an explanatory view showing the operation principle.

In FIG. 2, reference numeral 1 denotes an electromagnetic fuel injection valve, and an electromagnetic coil, a fixed core and the like (not shown) are built in the main body. A nozzle body 2 is attached to a lower portion of the main body of the fuel injection valve 1.

Here, the internal structure of the nozzle body 2 attached to the intake pipe 20 will be described with reference to FIG.

The nozzle body 2 is formed in a cylindrical shape, and a bottom portion 4 with a valve seat 3 is disposed at a substantially central position inside the nozzle body 2 in a raised state. A metering orifice 5 serving as a fuel nozzle is provided in the bottom portion 4 downstream of the valve seat 3. Top surface of nozzle body bottom 4 (measuring orifice 5
A swirler (fuel swirler) 6 that applies a swirling force to the fuel is disposed upstream of the fuel cell, and an air swirler having an air nozzle 7A and an air swirling chamber 7B is provided on the lower surface of the bottom 4 (downstream of the measuring orifice 5). 7 are arranged.

As shown in FIG. 2, the fuel swirler 6 is formed of a piece-shaped chip, and four fuel passage grooves 6A for applying a swirling force to the fuel are provided on the lower surface thereof. The groove 6A has a passage structure for guiding the fuel from the chip side wall to the valve guide hole 6B at the center of the chip, and each groove 6A is arranged at an angle that does not intersect the center of the valve guide hole 6B. 6B is arranged so as to maintain a substantially tangential relationship with the peripheral surface of 6B. The pressurized fuel that has exited from the groove 6A in this way forms a swirling flow along the wall surface of the guide hole 6B.

The air swirler 7 is also formed by a piece in the form of a piece.
On its upper surface, four groove-shaped air nozzles 7A for applying a turning force to the air are provided. The air nozzle 7A has a passage structure for guiding air from the chip side wall to the air swirling chamber 7B at the center of the chip, and each air nozzle 7A is arranged so as to maintain a substantially tangential relationship with the inner periphery of the swirling chamber 7B. Air nozzle 7A
Is set such that the direction of the air swirl flow is opposite to the above-described fuel swirl flow.

As shown in FIG. 1, an air swirl chamber 7B and an air nozzle 7A facing the air swirl chamber 7B have a measuring orifice (fuel nozzle).
5 is arranged adjacent to the outlet 5. The air nozzle 7A is provided with an air passage 2A provided on a side wall of the nozzle body 2.
Communicate with As the air source guided to the air passage 2A and the nozzle 7A, a differential pressure between the intake pipe 20 and the atmospheric pressure is used.
An air pump is used when the differential pressure drops below about 0.5 atm. In this case, the operation of the air pump is provided with hysteresis as shown in FIG. 5 to prevent hunting of the pump operation.

Reference numeral 8 denotes a ball valve which opens and closes the valve in cooperation with the valve seat 3. The ball valve 8 is connected to a plunger (not shown) via a rod 9 and is connected to the fuel swirler 6 by turning on and off an electromagnetic coil. The operation is guided by the provided guide hole 6B.

According to this embodiment, when the ball valve 8 is opened,
The fuel passes through the groove 6A of the fuel swirler 6 and is given a swirling force by the nozzle body guide hole 6B, and then is ejected through the measuring orifice 5 into the air swirling chamber 7B as a thin liquid film.
On the other hand, the air introduced into the air passage 2A and the nozzle 7A is provided with a swirling force and reaches the air swirling chamber 7B. Since the swirling directions of the air swirl flow and the fuel swirl flow are opposite to each other, these swirl flows collide with each other in the air swirl chamber 7B. Therefore, the fuel swirling flow immediately after the injection from the metering orifice 5 is mixed with the air while reducing the speed, and the atomization of the fuel is promoted.

The fuel which has not been atomized adheres to the wall surface of the air swirling chamber 7B. The adhered fuel is also separated from the wall by the force of the swirling air flow, is formed into a thin film, and is ejected from the nozzle body 2. The outlet 7C of the air swirler 7 expands in a tapered shape, and the spray spread angle is changed according to the spread angle.

According to this embodiment, immediately after the fuel is injected from the metering orifice 5, the swirling fuel flow merges with the swirling air flow. As a result, the fuel swirl collides with the air swirl in the opposite direction in the small swirl space before diffusion,
The swirling air flow is reduced as much as possible to mix the fuel and air and atomize the fuel, and to effectively and moderately decelerate the swirling fuel flow.

FIG. 3 is an experimental data diagram showing the relationship between the air flow rate for atomization and the spray particle size. The diagram plotted with circles shows the air swirling chamber immediately after fuel injection from the metering orifice 5 as in this embodiment. 7B, the fuel swirl flow and the air swirl flow in the opposite direction are combined. A diagram plotted by a square mark (Comparative Example 1) shows that the air flow without air swirl is fueled in the same air swirl chamber 7B as described above. A diagram (Comparative Example 2) plotted by triangles, in which the swirling flow is merged with the swirling flow, shows the fuel swirling flow injected from the measuring orifice 5 in the opposite direction outside the nozzle body 2 without using the air swirling chamber 7B. It is merged with the swirling flow.

As is apparent from the experimental data, the fuel of the present embodiment can reduce the amount of air for atomization introduced to the fuel injection valve and reduce the amount of injected fuel as compared with Comparative Examples 1 and 2. did it.

FIG. 4 is a diagram showing the relationship between the air flow rate and the spray speed. As shown in FIG. 4A, when there is no air swirling, the spray speed increases when the air flow rate around the injected fuel is increased. However, as shown in FIG. 4B, an air swirling flow in the opposite direction is added to the fuel swirling flow. And the spray speed in the jetting direction decreases. For this reason, the injected fuel is easily carried by the airflow of the intake pipe, and the adhesion of fuel to the intake pipe wall surface can be prevented.

FIG. 6 is a sectional view showing a main part of a second embodiment of the present invention. In the figure, the same reference numerals as those in the first embodiment indicate the same or common elements (the same applies to the reference numerals in the other embodiments after FIG. 7).

The second embodiment is substantially similar in structure to the first embodiment. The air swirler 7 is provided so as to be in contact with the outlet of the measuring orifice 5.
The point that the outlet 7C formed downstream of the air swirl chamber is smaller than the area of the air swirling chamber 7B.

In this manner, in addition to the same effect as in the first embodiment, there is an advantage that the air and the fuel are mixed in the narrow area 7C to increase the atomization and the air mixing ratio.

FIG. 7 is a sectional view showing a main part of a third embodiment of the present invention.

The main structure of this embodiment is the same as that of each of the above embodiments, except that a protrusion 10 is provided on the periphery of the outlet 7C of the air swirler 7.

When the flow rate of the air is small, the fuel and the air that have flowed out of the air swirler 7 are easily wrapped around the bottom surface 7D of the air swirler 7 to form coarse particles.
Is provided, the liquid film is formed as a thin film on the inner wall of the protruding portion 10 and adheres to prevent the liquid film from wrapping around the bottom surface 7D. As a result, the attached fuel can continuously flow down in a thin film state before growing as droplets from the tip of the protruding portion 10, so that the fuel can be further atomized.

FIG. 8 shows a fourth embodiment of the present invention. This embodiment has almost the same structure as the second embodiment of FIG. 6, but additionally has a groove 11 formed along the periphery at the end of the outlet guide 2 ′ of the nozzle body 2. If the air flow is low,
The fuel that has flowed into the guide portion 2 ′ is supplemented by the groove 11, so that the ejection of coarse particles is small, and when the air flow rate is large, the fuel that has accumulated in the groove 11 is sucked out by the air and is atomized. .

FIG. 9 shows a fifth embodiment of the present invention. This embodiment also has the same configuration as the above embodiments for the main part, except for the lower end 7-1 of the air swirling chamber 7B in the air swirler 7.
Is formed in a tapered shape, and then the nozzle body fine holes 7-
2, and then the outlet portion 7C is expanded in a tapered shape.
In this way, after the swirling flows of the fuel and the air merge in the air swirling chamber 7B, the air and the fuel are guided to the pores 7-2 without loss. And the swivel 7
The spray angle can be controlled by the taper angle of the outlet 7C. If the taper angle is 25 degrees, the spray spread angle is also about 25 degrees.

FIG. 10 is a plan view of the air swirler 7 used in the sixth embodiment of the present invention, and FIG. 11 is a vertical sectional view taken along the line AA of FIG.

In this embodiment, only the air swirler 7 is shown, but its arrangement is the same as in each of the above embodiments. In this embodiment, the air swirling chamber 7B of the air swirler 7 is used.
The lower end 7-1 is tapered and formed in the same manner as in the fifth embodiment, but directly under the lower end 7-1.
Form c.

By doing so, the passage of the outlet portion 7C becomes the narrowest among the passages of the air swirling flow (the air nozzle 7).
Since the passage area of the outlet 7C is smaller than the total area of A), the flow rate of the air introduced into the swirler 7 is determined by the outlet 7C. Also, by narrowing the passage from 7-1 to 7C, the speed of the air swirl flow can be increased, and the collision force with the fuel swirl flow in the opposite direction can be reduced to reduce the fuel injection speed and atomize the fuel. It can be achieved even more.

FIG. 12 is a sectional view showing a main part of a seventh embodiment of the present invention.

This embodiment also has the same principal parts as the above embodiments, except that a cylindrical cover 12 is attached to the lower part of the main body 1 of the fuel injection valve, and the cover 12 is interposed between the cover 12 and the fuel injection valve 1. An air passage 12A communicating with the nozzle 7A of the air swirler 7 and the air passage 2A of the nozzle body 2 is formed.

FIG. 13 is a schematic sectional view showing an eighth embodiment of the present invention.

In this embodiment, a nozzle body 2 having a metering orifice 5 is provided below the fuel injection valve 1, and an air swirler 7 is provided below the nozzle body 2 so as to be in contact with the metering orifice 5. A cover 13 that covers a lower portion of the main body of the fuel injection valve 1 is attached to a lower portion of the air swirler 7. The cover 13 has an injection port 14 for ejecting mixed air and fuel.
And an air inlet 15 are provided.

The air swirler 7 is provided at the lower end 7 of the air swirling chamber 7B.
The air swirler 7 is inserted into the nozzle body 2 and the cover 13 so as to be narrowed. In this assembled state, the tapered air swirl restrictor 7-1 communicates with the injection port 14 provided on the cover 13 side. Further, an air passage 13A communicating with the air nozzle 7A is formed between the cover 13 and the fuel injection valve 1. Note that, also in this embodiment, a fuel swirler (not shown) is disposed upstream of the measuring orifice 5.

In this embodiment, the cover 13 is attached to the fuel injection valve by a simple means such as press-fitting, so that an air passage 13A leading to the air swirler 7 is secured.
The injection port 14 and the air swirler 7 provided on the side of FIG.
An air swirling structure similar to the embodiment can be obtained. The structure itself of the air swirler 7 in this case has an advantage that it can be simplified as compared with the sixth embodiment.

FIG. 14 is a sectional view showing a ninth embodiment of the present invention.

In this embodiment, similarly to the cover 13 of the eighth embodiment, a cover 16 is attached below the fuel injection valve 1. Cover 1
6 is provided with a tapered outlet 16A and an air inlet 16B for guiding the fuel and air that have been joined by the air swirler 7 and mixed.

The air swirler 7 is arranged so as to be in contact with the outlet of the metering orifice 5, and is sandwiched between the cover 16 and the nozzle body 2 provided below the fuel injection valve 1.

An air passage 17 communicating with the air nozzle 7A of the air swirler 7 is formed between the cover 16 and the fuel injection valve 1.

FIG. 15 shows a tenth embodiment of the present invention. FIG. 15 (a) is a sectional view of a main part, and FIG. 15 (b) is a view of a part of the nozzle body viewed from below.

Also in this embodiment, the fuel swirler 6 is arranged upstream of the metering orifice 5 in the nozzle body 2, but the air swirler as described so far is not arranged thereunder.
Downstream of the orifice 5 is a space (mixing chamber) 2B for mixing the injected fuel and air.

At the bottom 4 of the nozzle body 2, a mixing chamber 2B
Air passage 2 that guides air from outside to the air to generate air flow
Although A is formed, its outlet (air nozzle) 2A-1 is formed in a ring shape so as to expand toward the outlet.

The annular air outlet 2A-1 is arranged so as to face the mixing chamber 2B at the bottom 4 of the nozzle body.
As shown in (b), the orifice 5 is
It is arranged so as to be concentric with.

In the present embodiment, the fuel swirled from the metering orifice 5 is injected into the mixing chamber 2B,
The air that is injected into the mixing chamber 2B through the air nozzle A and the annular air nozzle 2A-1 becomes an air flow that expands in a conical shape as indicated by an arrow. This has the following advantages.

As shown in the spray particle size distribution in FIG. 16, when air is not flown into the mixing chamber 2B, the spray particle size of the hollow conical fuel swirl flow is larger than the center in the distribution. Tend to be larger. This is because the inertia force increases as the spray particle size increases.

For such a particle size distribution, an annular air nozzle 2A-1 is provided, and the conical air flow injected from the air nozzle 2A-1 is applied to the region having the largest particle size. If the exit radius is set, the air flow mainly collides with the portion of the fuel spray of the coarse particles, so that the entire spray can be atomized with a small amount of air.

FIG. 17 shows an eleventh embodiment of the present invention.

In this embodiment, as in the tenth embodiment shown in FIG. 15, an annular air nozzle 2A'-1 is formed on the bottom 4 of the nozzle body.
Is arranged so as to be concentric with the orifice 5 by approaching the orifice 5, and the air outlet 2A'-1 is installed so as to allow a straight cylindrical air flow. Since the air ejected from the air outlet 2A'-1 has a high speed immediately after the injection, the air can collide with the fuel in a region where the speed is high, and the atomization can be achieved.

FIG. 18 shows a twelfth embodiment of the present invention.

In this embodiment, similarly to the tenth and eleventh embodiments, an annular air nozzle 2A-2 concentric with the orifice 5 is provided around the measuring orifice 5.
-2 points toward the center. According to this embodiment, the spread angle of the entire spray can be reduced.

FIG. 19 shows a thirteenth embodiment of the present invention, in which (a) is a sectional view of a main part and (b) is a bottom view.

In this embodiment, a plurality of air nozzles 2A-3 are provided on the bottom 4 of the nozzle body 2.

The air nozzles 2A-3 are directed toward the center, and the air nozzles 2A-3 are paired to sandwich the metering orifice (fuel nozzle) 5 therebetween.
Are arranged at an equal distance from each other.

For this reason, the fuel ejected from the metering orifice 5 is atomized while being bent toward the center by air, and the fuels that could not be atomized collide with each other and are atomized. According to the test results, by setting the offset d of the air nozzle 2A-3 to about half the size of the air nozzle body, it is possible to prevent the fuel particles from re-condensing at the center of the spray and to obtain the smallest particles. Was.

FIG. 20 shows a fourteenth embodiment of the present invention.

This embodiment corresponds to two intake valves / one cylinder. A metering orifice 5 is provided downstream of a valve body 8, and two fuel nozzles 5-1 and 5-2 are further branched downstream therefrom. Provided. Further, an air swirling chamber 7B and an air swirler 7 with an air nozzle 7A are provided downstream of the fuel nozzles 5-1 and 5-2 while adjoining these nozzles.

The air swirling chamber 7B is provided with fuel nozzles 5-1 and 5-
2 are formed corresponding to the air swirling chambers 7B.
The orifices 7E and 7F serving as outlets of 7B are arranged in the air swirler 7 in correspondence with the above. The orifice 7E is disposed on the extension of the fuel nozzle 5-1 so as to be aligned with the nozzle 5-1 at an angle, and the orifice 7F has the same relationship with the fuel nozzle 5-2.

According to this embodiment, the fuel nozzles 5-1 and 5
-2 from the nozzle 5
Immediately after exiting -1, 5-2, it collides with swirling air and becomes fine. The atomized fuel colliding with the swirling air is divided into two directions by orifices 7E and 7F, and is respectively distributed toward the intake valves of the cylinders.

FIG. 21 shows a fifteenth embodiment of the present invention.

This embodiment also has the same structure as the twelfth embodiment, except that the fuel nozzles 5-1 and 5-2 are formed by a thin plate (having a thickness of 0.2 mm or less) 21 separate from the nozzle body 2. This simplifies the structure of the nozzle body 2 and facilitates molding.

When the fuel passage 6A is opened by the valve body 8 which is electromagnetically driven, the fuel ejected from the fuel nozzle 5 causes the plurality of holes 5-1 and 5-
2 and a plurality of air nozzles 2A
The fuel atomization is promoted by colliding with the air injected from the
Further, the above-described fuel is divided in a plurality of directions by a member 7 provided downstream of the air nozzle 2A.

FIG. 22 shows a sixteenth embodiment of the present invention.

In this embodiment, the fuel nozzle 5 is branched into two nozzles 5-1 and 5-2 which are directed in the axial direction on the way, and a thin air swirl is provided adjacent to the nozzles 5-1 and 5-2. The chamber 7B is arranged, and the orifices 7E and 7F are further provided downstream thereof. The orifices 7E and 7F are defined by screens 40 having a triangular cross section.

The air flowing into the swirl chamber 7B from the air passage 2A collides with the thin film fuel injected from each of the fuel nozzles 5-1 and 5-2 to atomize the fuel. Some of the fuel adheres to the slope of the partition 40 in a thin film form, but is wiped off by swirling intake air to be atomized. In this way a small spray is formed,
The jet is directed by the orifices 7E and 7F.

FIG. 23 shows a seventeenth embodiment of the present invention. FIG. 23 (a) is a sectional view of a main part thereof, and FIG. 23 (b) is a bottom view.

Also in this embodiment, an air swirl chamber 7B 'is formed downstream of the fuel nozzle 5 for injecting swirl fuel and adjacent to the outlet of the nozzle 5, and the air swirl chamber 7B' has a swirl flow of fuel. An air nozzle 7A 'is arranged to generate an air flow in the same direction.

Further, a plate 22 having an eyeglass-shaped hole 23 is disposed immediately below the air swirling chamber 7B '.

According to such a configuration, it is possible to cope with two intake valves / one cylinder by the following operation. For example, intake pipe 2
When the pressure difference between the inside of the air chamber 0 and the atmosphere is small and there is almost no air introduced from the air passage 2A into the air swirling chamber 7B ', the fuel spreads in two directions of the eyeglass holes 23 by its own swirling force, Form two sprays. When the air is introduced, the swirling of the fuel is further accelerated by the air flow, a thin liquid film is formed and the spray particle diameter is reduced, and the swirling force can spread the fuel in the eyeglass hole 23 in two directions.

FIG. 24 shows an eighteenth embodiment of the present invention. FIG. 24 (a) is a sectional view of a main part thereof, and FIG. 24 (b) is a bottom view.

In this embodiment, a branch hole 24 is formed adjacent to the outlet 7C 'of the air swirl chamber 7B' as in the seventeenth embodiment.
A plate 24 having A is placed. Air swirl chamber 7B '
The fuel atomized by the above can be divided into two directions at the hole 24A, and the direction coincides with the branching direction by the hole 24A.

FIG. 25 is a sectional view of a main part of a nineteenth embodiment of the present invention, FIG. 26 is a plan view of a fuel branch plate used in the nineteenth embodiment, and FIG. 27 shows an operation state of fuel passing through the fuel branch plate. .

This embodiment differs from the previous embodiments in that a fuel branch plate 22 is provided downstream of the fuel nozzle 5 for injecting swirl fuel, and an air swirl chamber 7B is formed further downstream.

As shown in FIGS. 26 and 27, the plate 22 is formed by a pair of glasses-like holes 23 (two holes 24A as shown in FIG. 24 may be provided). -1 and 7B-2 are provided. The air swirling chambers 7B-1 and 7B-2 are provided with air nozzles 7A so as to generate an air swirling flow opposite to the fuel swirling direction injected from the fuel nozzle 5. These elements 7A, 7B-1 and 7B-2 are formed on a chip serving as a main body of the air swirler 7.

With such a structure, as shown in FIG. 27, the swirling fuel injected from the fuel nozzle 5 is first divided into two by the eyeglass holes 23, and thereafter, the swirling fuel is divided into the respective air swirling chambers 7B. In the process of passing through -1 and 7B-2, it collides with the swirling airflow in the opposite direction, and the atomization is promoted.

FIG. 28 shows a twentieth embodiment of the present invention, in which (a) is an explanatory view of a main part and (b) is a bottom view.

In this embodiment, an orifice plate 26 having a plurality of orifices (fuel nozzles) 27 is disposed downstream of the orifice 5 serving as a fuel passage without providing a fuel swirler, and each orifice 27 has a plurality (two or more). ) Are paired,
The fuel injected from the pair of orifices 27 is configured to collide. Downstream of the orifice 27, two orifices 28A and 28B for turning air are provided.

Each of the orifices 28A and 28B for swirling air is introduced from outside the fuel injection valve 1 through an air passage 29 to generate an swirling air flow.

Thus, fuel is injected into each of the orifices 28A, 28B from a pair of fuel nozzles 27. Immediately after this injection, each of the orifices 28A, 28B is injected.
The fuel is swirled by the air swirling flow to form a thin film, and thereafter, the fuels collide with each other, are further thinned, and partly atomized. Thereafter, the thin film is atomized by air, and a small spray can be obtained.

FIG. 29 shows a twenty-first embodiment of the present invention, in which (a) is a sectional view of a nozzle body used for a fuel injection valve.
(B) is a bottom view.

In the present embodiment, the nozzle body 30 includes:
A plurality of fuel nozzles 31 are arranged, each fuel nozzle 31 forms a pair, and the paired nozzles 31 are set at an angle such that the injected fuel collides on the way. An orifice 33 serving as an air swirl chamber is provided adjacent to each fuel nozzle 31. Numeral 32 denotes a nozzle with an air passage for introducing air from the outside. The air nozzle 32 is eccentrically facing the air swirling chamber 33 (for example, tangential to the peripheral surface of the air swirling chamber 33). , Air swirl chamber 33
The air to be introduced into the air is swirled.

With such a structure, the fuel injected from each fuel nozzle 31 is given a swirling force in the air swirling chamber 33 immediately after the injection and accelerated into a thin film as in the twentieth embodiment. After that, the injected fuels of the pair of nozzles 31 collide with each other, further form a thin film and partly atomize,
Thereafter, the fuel in the form of a thin film is mixed with air and atomized to obtain a small spray.

FIG. 30 shows a twenty-second embodiment of the present invention.

In this embodiment, the fuel nozzle 5 is provided below the fuel injection valve 1, and the cover 34A,
A cylindrical body 34 having a double wall structure made of 34B is provided. Cylinder 3
The inside of the inner cover 34 of 4 is a passage 36 for the injected fuel, and a partition 37 for colliding the passing fuel is provided at the outlet of the passage 36 by dividing the passage into two or more (here, two). The partition 37 has a triangular cross section.

The annular space between the inner cover 34A and the outer cover 34B serves as an air passage 35, and the inlet side of the air passage 35 communicates with the air introduction passage 2A provided in the nozzle body 2, and the inner cover 34A approaches the partition 37. An air nozzle 38 is formed at the position indicated. The cylinder 34 extends into the engine intake pipe toward the intake valve of the engine.

With this configuration, the fuel nozzle 5
The fuel injected from the cylinder passes through the internal passage 36 of the cylinder 34, and when much of the fuel passing through the cylinder 34 collides with the slope of the partition 37 when ejected from the exit of the cylinder 34, a part of the fuel is atomized and the cylinder 34 is atomized.
The liquid remaining on the screen 37 while squirting from the screen 37 forms a thin liquid film on the screen 37. Then, the air passing through the air passage 34 is ejected from the air nozzle 38 to the partition 37, and the fuel on the partition surface is blown off by the air to be atomized by the air. In such a configuration, since the spray can be supplied near the intake valve of the engine, there is an advantage that the amount of fuel attached to the intake pipe wall surface is small.

[0094]

According to the present invention, efficient fuel atomization can be achieved with a small air flow rate, and the structure of such a fuel injection valve can be easily realized.
Further, such a fuel injection valve can be applied to an engine of a type having a plurality of intake valves per cylinder.

[Brief description of the drawings]

1A is a cross-sectional view of a main part of a first embodiment of the present invention, FIG.
(B) shows an arrangement structure of the air swirling chamber and the air nozzle.

FIG. 2 is an operation principle diagram of the fuel injection valve used in the first embodiment.

FIG. 3 is a diagram showing the relationship between the spray particle size and the amount of air required for atomization in the first embodiment and a comparative example.

FIG. 4 is a diagram showing a relationship between an air flow rate and a spray speed in the first embodiment and a comparative example.

FIG. 5 is a diagram showing operating conditions of an air supply pump used in the first embodiment.

FIG. 6 is a sectional view of a main part showing a second embodiment of the present invention.

FIG. 7 is a sectional view of a main part showing a third embodiment of the present invention.

FIG. 8 is a sectional view of a main part showing a fourth embodiment of the present invention.

FIG. 9 is a sectional view showing a main part of a fifth embodiment of the present invention.

FIG. 10 is a plan view of an air swirler used in a sixth embodiment of the present invention.

FIG. 11 is a sectional view taken along line AA of FIG. 10;

FIG. 12 is a sectional view of a main part showing a seventh embodiment of the present invention.

FIG. 13 is a sectional view showing a main part of an eighth embodiment of the present invention.

FIG. 14 is a sectional view showing a ninth embodiment of the present invention.

15A is a cross-sectional view of a main part, and FIG. 15B is a bottom view, in a tenth embodiment of the present invention.

FIG. 16 is an explanatory diagram showing a particle size distribution of swirl injection fuel.

17 (a) is a sectional view of a main part, and FIG. 17 (b) is a bottom view of the eleventh embodiment of the present invention.

18A is a cross-sectional view of a main part, and FIG. 18B is a bottom view, in a twelfth embodiment of the present invention.

FIGS. 19A and 19B are cross-sectional views of essential parts and FIG. 19B is a bottom view of the thirteenth embodiment of the present invention.

FIG. 20 is a sectional view showing a main part of a fourteenth embodiment of the present invention.

FIG. 21 is a sectional view showing a main part of a fifteenth embodiment of the present invention.

FIG. 22 is a sectional view of a main part showing a sixteenth embodiment of the present invention.

23 (a) is a sectional view of a main part, and FIG. 23 (b) is a bottom view of the seventeenth embodiment of the present invention.

24 (a) is a sectional view of a main part, and FIG. 24 (b) is a bottom view of the eighteenth embodiment of the present invention.

FIG. 25 is a sectional view showing a main part of a nineteenth embodiment of the present invention.

FIG. 26 is a plan view of a fuel branch member used in the nineteenth embodiment.

FIG. 27 is an explanatory view showing an operation state of the nineteenth embodiment.

28A is a cross-sectional view of a main part, and FIG. 28B is a bottom view of the twentieth embodiment of the present invention.

29 (a) is a sectional view of a main part, and FIG. 29 (b) is a bottom view of the twenty-first embodiment of the present invention.

30 (a) is a sectional view of a main part, and FIG. 30 (b) is a bottom view of the twenty-second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel injection valve, 2 ... Nozzle body, 2A ... Air nozzle, 5 ... Fuel nozzle, 5-1 and 5-2 ... Multiple holes (branch nozzles), 6A ... Fuel passage, 7 ... Fuel branching member, 8
... valve body, 21 ... thin plate.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Norio Shigeru 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Mamoru Fujieda 4026 Kuji-machi, Hitachi City, Ibaraki Prefecture Hitachi, Ltd Inside the Hitachi Research Laboratory

Claims (5)

[Claims] An electromagnetically driven valve body, a fuel passage opened and closed by the valve body, a fuel nozzle formed downstream of the fuel passage, and a plurality of holes, the fuel nozzle being downstream of the fuel nozzle And a plurality of air nozzles for introducing air that collides with fuel injected through the thin plate, and a member that is disposed downstream of the air nozzle and branches the fuel into a plurality of pieces. A characteristic electromagnetic fuel injection valve. 2. The electromagnetic fuel injection valve according to claim 1, further comprising means for swirling fuel upstream of the fuel passage. 3. The electromagnetic fuel injection valve according to claim 1, wherein the plurality of air nozzles are arranged at an angle that does not intersect the center of the fuel nozzle when viewed in a cross section perpendicular to the axis of the fuel nozzle. 4. A means for swirling fuel upstream of the fuel passage, wherein the plurality of air nozzles do not intersect the center of the fuel nozzle when viewed in a cross section perpendicular to the axis of the fuel nozzle. The electromagnetic fuel injection valve according to claim 1, wherein: 5. The electromagnetic fuel injection valve according to claim 1, wherein the thin plate has a thickness of 0.2 mm or less.