JP2001107824A - Solenoid fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid fuel injection valve to improve machinability of an injection hole 24, reduce emission at low fuel consumption through promotion of combustion by atomization of injection fuel, and further facilitate the execution of the specification of spray injected through an injection nozzle, a flow rate specification, or control characteristics. SOLUTION: It is noticed that an injection nozzle 24 part formed in a nozzle body 4 is formed in other part (an orifice plate 22). The orifice plate 22 is fixed at a plate fixing space part 21 formed at the nozzle body 4 on the side situated downstream from a seat part 7, and at least one pair of injection hole 24 are formed in the orifice plate 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic fuel injection valve, and more particularly to an electromagnetic fuel injection valve for direct injection of in-cylinder fuel of a type in which gasoline or other fuel is directly injected into a combustion chamber. .

[0002]

2. Description of the Related Art A conventional electromagnetic fuel injection valve for direct in-cylinder fuel injection has a cone shape using a swirl flow of fuel. There are limits to improving. Therefore, for example, Japanese Utility Model Application Laid-Open No. 59-172276,
-83366, JP-A-8-144762, JP-A-8-144
As disclosed in JP-A-177499, high pressure fuel is injected from at least a pair of injection holes and then collided with each other to change the spray shape or to spray as a flat spray.

[0003] An electromagnetic fuel injection valve for obtaining a spray having a flat shape will be outlined based on Figs. 9 and 10.
FIG. 9 is a longitudinal sectional view of a main part of a conventional electromagnetic fuel injection valve 1. The electromagnetic fuel injection valve 1 includes an electromagnetic coil 2, an armature 3, a nozzle body 4, a needle valve 5,
A return spring 6.

[0004] In the nozzle body 4, a seat portion 7 of the needle valve 5 is formed, a fuel reservoir chamber 8 is formed on the upstream side thereof, and an injection hole upstream side space portion 9 is formed on the downstream side thereof. A pair of opposed injection holes 10 are formed in communication with the hole upstream side space 9.

FIG. 10 is a bottom view of the combustion chamber facing surface 11 of the nozzle body 4 as viewed from the combustion chamber 12 side, wherein the pair of injection holes 10 have a predetermined inclination angle (the axis 5 of the needle valve 5).
The combustion chamber 12 is viewed with a tilt angle θ with respect to C and a relative interval (pitch P).

In the electromagnetic fuel injection valve 1 having such a configuration, the return spring 6 is activated by the excitation of the electromagnetic coil 2.
The armature 3 is driven against the urging force of the armature 3, and the needle valve 5, which is driven integrally with the armature 3, lifts from the seat portion 7, and injects high-pressure fuel into the combustion chamber 12 through the injection hole 10.

The jets of the injected fuel injected from the pair of injection holes 10 collide with each other in the combustion chamber 12 to form a flat spray 13 (fan spray). Specifically, a pair of high-pressure jets from a pair of injection holes 10 spread from a collision portion in a direction perpendicular to a plane including the jets. In other words, the jet is uniformly spread in an approximately oval or flat shape in which the front side in the collision direction of the jet is wide and the side side is narrow, so that atomization of the fuel is realized by the collision of the high-pressure jet, and combustion occurs. Mixing with the air in the chamber 12 is performed well. Since the shape or form of the spray 13 is thin and wide, the adhesion of fuel to the top surface of the piston 14 when the piston 14 ascending in the combustion chamber 12 is compressed can be suppressed, and deterioration of emission can be prevented.

However, the nozzle body 4 itself usually needs to be made of, for example, SUS440C or another hardened material having a relatively high hardness, and there is a problem that machining of the injection hole 10 is difficult.

Further, the injection holes 10 are formed in the combustion chamber 12.
Although the machining accuracy for ensuring that the jets of the injected fuel from colliding with each other is good, it is difficult to easily change various specifications such as the diameter of the injection hole 10 and the inclination angle θ, and the combustion of the internal combustion engine is difficult. There is a problem that it is difficult to obtain a large variation in the spray 13 or the injection amount by the electromagnetic fuel injection valve 1 according to the characteristics and the like.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides an electromagnetic fuel injection valve capable of improving the atomization of injected fuel and the mixing property with air. That is the task.

Another object of the present invention is to provide an electromagnetic fuel injection valve capable of improving the workability of an injection hole.

Further, the present invention provides an electromagnetic fuel injection valve capable of reducing the emission with low fuel consumption by promoting the combustion by the atomization of the injected fuel to reduce the emission and promoting the mixing of the injected fuel and the air. The task is to provide.

Another object of the present invention is to provide an electromagnetic fuel injection valve capable of easily executing the specification and flow rate specification of the spray injected from the injection hole or its characteristic control.

[0014]

That is, the present invention focuses on forming an injection hole portion formed in a nozzle body in another part (orifice plate). A nozzle body having at least a pair of injection holes formed so that they collide with each other in the combustion chamber, and a needle valve that can open and close the injection holes by exciting the electromagnetic coil while seating on a seat portion of the nozzle body. An electromagnetic fuel injection valve having the jets of fuel injected from the injection holes collide with each other and injecting them as flat-shaped sprays, wherein the nozzle body is located downstream of the seat portion. The orifice plate was fixed in the formed plate fixing space, and the injection hole was formed in this orifice plate. An electromagnetic type fuel injection valve according to claim.

The orifice plate may have a rectangular cross section.

[0016] An injection hole introducing space which is continuous with the upstream opening of the injection hole can be formed on the upstream surface of the orifice plate.

The degree of the flat shape of the spray can be adjusted by selecting the inclination angle of each of the injection holes with respect to the axis of the needle valve.

By selecting the injection hole pitch between the axes of the injection holes, the degree of the flat shape of the spray can be adjusted.

The number of the above-mentioned injection holes is not limited to a pair, and may be an arbitrary number, and the formation position thereof is also arbitrary as long as at least a pair of the injection holes can form a flat spray.

In the electromagnetic fuel injection valve according to the present invention, since at least one pair of injection holes is formed in the orifice plate which is a member separate from the nozzle body, this orifice plate is made of another material different from the nozzle body. For example, a material having good workability such as SUS304 can be adopted. By adjusting the inclination angle and the diameter of the injection holes and the pitch between the injection holes, the specification of the spray or the flow rate can be varied.

Further, by making the orifice plate have a simple rectangular cross section, it is possible to ensure simple and reliable structure for fixing the orifice plate to the nozzle body and easiness of processing the injection hole.

Further, by forming an injection hole introduction space portion which is continuous with the upstream opening portion of the injection hole on the upstream surface of the orifice plate, the lateral expansion of the injection hole introduction space portion is adjusted, and the injection hole introduction space is adjusted. The degree of freedom in selecting the diameter of the hole and the angle of inclination can be increased.

Further, the degree of the flat shape of the spray can be adjusted by selecting the respective inclination angles of the injection holes with respect to the axis of the needle valve or the pitch of the injection holes between the respective axes of the injection holes.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an electromagnetic fuel injection valve 20 according to an embodiment of the present invention will be described with reference to FIGS. However, the same parts as those in FIGS. 9 and 10 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a longitudinal sectional view of a main part of an electromagnetic fuel injection valve 20. In the electromagnetic fuel injection valve 20, a side of the combustion chamber 12 of the nozzle body 4 of the above-mentioned electromagnetic fuel injection valve 1 (FIG. 9) is shown. A circular plate fixing space portion 21 is formed in the plate fixing space portion 21.
The orifice plate 22 is fixed by welding (welded portion 23) or the like. FIG. 2 is a bottom view of the orifice plate 22 as viewed from the combustion chamber 12 side.

The orifice plate 22 is made of a disc material having a rectangular cross section and has a good workability, for example, SUS304 or the like. The injection holes 24 are opposed to each other,
Further, it is formed so as to penetrate at a predetermined inclination angle θ with respect to the axis 5C of the needle valve 5.

A circular injection hole introduction space 25 facing the upstream opening 24A of the injection hole 24 is provided on the upstream surface 22A of the orifice plate 22 on the injection hole upstream space 9 side.
Is formed. The injection hole introduction space 25 includes upstream openings 24A of the respective injection holes 24 therein, and the high-pressure fuel passes through the injection holes 24 through the injection hole introduction spaces 25.
Will be introduced inside. Accordingly, the orifice plate 22 can be used regardless of the width or width of the injection hole upstream space 9 in the horizontal direction in FIG. 1, that is, without changing the size of the injection hole upstream space 25 from the existing space. Injection holes 2 at any part of the
4 can be formed. The injection hole introduction space 2
The shape of No. 5 is not limited to the above-mentioned circular shape, and any shape including the upstream openings 24A of the pair of injection holes 24 inside the pair may, for example, secure a necessary minimum flow path and reduce the dead volume. A possible elliptical shape or any other shape can be employed. Further, the number of the injection holes 24 is not limited to one pair, but may be two or more. Alternatively, an arbitrary number of injection holes may be provided at arbitrary positions in order to obtain a desired spray shape.

In the electromagnetic fuel injection valve 20 having such a configuration, the needle valve 5 is lifted from the seat portion 7 of the nozzle body 4 by driving the armature 3 and the needle valve 5 by exciting the electromagnetic coil 2, and the fuel accumulation chamber 8 is formed. High-pressure fuel flows from the combustion chamber 1 through the injection hole upstream space 9, the injection hole introduction space 25, and the injection hole 24.
2, where the jets collide with each other to form a flat spray 13.

FIG. 3 is a side view of the spray 13 on the wide angle side (larger spread side), and FIG. 4 is a side view of the spray 13 on the narrow angle side (thinner flat side). Thus, with the spray 13 having such a shape, the atomization of the fuel is uniformly promoted by the collision of the jet, and the mixing state with the air in the combustion chamber 12 can be improved. Further, even in the atmosphere under the back pressure due to the compression of the piston 14, the thin and wide spray form is maintained. Further, the penetration (penetration force) of the spray 13 can be controlled by the fuel pressure.

FIG. 5 is an explanatory view of the inclination angle θ of the injection hole 24 with respect to the axis 5C of the needle valve 5, and FIG.
Is an explanatory diagram of the pitch P between the centers of the injection holes 10,
Arbitrary spray 13 can be obtained by appropriately adjusting the inclination angle θ and the pitch P. In particular,
When the inclination angle θ increases, the spray 13 opens and the shape becomes flatter. The smaller the pitch P, the more the spray 13 opens, and the more flat the shape. For example, FIG. 7 is an explanatory view of the orifice plate 26 having a small inclination angle θ, and FIG.
FIG. 4 is an explanatory view of an orifice plate 27 with a larger size.
These orifice plate 22 (FIG. 1), orifice plate 26 (FIG. 7) or orifice plate 27
By appropriately combining (FIG. 8) with the nozzle body 4, it is possible to obtain the spray 13 having an arbitrary spray form and flow rate specification.

The upstream surface 22 of the orifice plate 22
Since the injection hole introduction space 25 is formed in A, the size or expansion of the injection hole introduction space 25 is ensured, so that the position of the upstream opening 24A of the injection hole 24 positioned inside the space 25 is secured. And the size can be controlled, and the diameter, the inclination angle θ, or the pitch P of the injection hole 24 can be selected with an arbitrary degree of freedom to set an arbitrary spray specification of the spray 13 and a flow rate specification such as an arbitrary high injection amount. Obtainable.
Thus, it is possible to form a flat spray 13 (fan spray) by the collision of the jets from the plurality of injection holes 24, atomize the fuel, and form the spray 13 in the back pressure atmosphere in the combustion chamber 12. Is maintained thin and wide, the degree of freedom of injection into the combustion chamber 12 can be increased.

[0031]

As described above, according to the present invention, a separate orifice plate is fixed to the nozzle body and at least a pair of injection holes are formed in the orifice plate. , The fuel efficiency and emission based on the promotion of combustion can be reduced, the degree of freedom of spray shape, angle, flow rate, etc. can be increased, and the workability of the injection hole can be improved.

[Brief description of the drawings]

FIG. 1 shows an electromagnetic fuel injection valve 2 according to an embodiment of the present invention.
0 is a longitudinal sectional view of a main part of FIG.

FIG. 2 is a bottom view of the orifice plate 22 as viewed from the combustion chamber 12 side.

FIG. 3 shows the same spray 1 on the wide-angle side (larger spread side).
It is a side view of No. 3.

FIG. 4 is a side view of the spray 13 on the narrow angle side (the thinner and flatter side).

FIG. 5 is an explanatory diagram of an inclination angle θ of the injection hole 24 with respect to an axis 5C of the needle valve 5;

FIG. 6 is an explanatory diagram of a pitch P between centers of the injection holes 10;

FIG. 7 is an explanatory view of the orifice plate 26 in which the inclination angle θ is reduced.

FIG. 8 is an explanatory view of an orifice plate 27 in which the pitch P is increased.

FIG. 9 is a longitudinal sectional view of a main part of a conventional electromagnetic fuel injection valve 1.

FIG. 10 is a bottom view of the combustion chamber facing surface 11 of the nozzle body 4 as viewed from the combustion chamber 12 side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electromagnetic fuel injection valve (FIG. 9) 2 Electromagnetic coil 3 Armature 4 Nozzle body 5 Needle valve 5C Axis of needle valve 6 Return spring 7 Seat portion 8 Fuel storage chamber 9 Upstream space portion of injection hole 10 A pair of injection holes 11 Combustion chamber facing surface of nozzle body 4 12 Combustion chamber 13 Flat spray (fan spray) 14 Piston 20 Electromagnetic fuel injection valve (Embodiment, FIG. 1) 21 Plate fixing space 22 Orifice plate 22A Upstream of orifice plate 22 Side surface 23 Welded part 24 A pair of injection holes 24A Upstream opening of injection hole 24 25 Injection hole introduction space 26 Orifice plate with reduced inclination angle θ (FIG. 7) 27 Orifice plate with increased pitch P (FIG. 8) θ injection hole 10 (FIG. 9) or injection hole 24 (FIG. 1)
(Inclination angle of needle valve 5 with respect to axis 5C) P Relative interval (pitch) between each of a pair of injection holes 10 (FIG. 9) or a pair of injection holes 24 (FIG. 1).

Claims (5)

[Claims] An electromagnetic coil; a nozzle body having at least a pair of injection holes formed so that jets of the respective injected fuels collide with each other in a combustion chamber; A needle valve capable of opening and closing the injection hole by excitation of a coil; and an electromagnetic fuel injection valve configured to collide the jets of the fuel injected from the injection hole with each other and inject as a flat spray. An electromagnetic fuel injection valve, wherein an orifice plate is fixed in a plate fixing space formed in the nozzle body downstream of the seat portion, and the injection hole is formed in the orifice plate. 2. The electromagnetic fuel injection valve according to claim 1, wherein the orifice plate has a rectangular cross section. 3. The electromagnetic fuel injection valve according to claim 1, wherein an injection hole introduction space portion that is continuous with an upstream opening of the injection hole is formed on an upstream surface of the orifice plate. 4. Selecting the respective inclination angle of the injection holes with respect to the axis of the needle valve,
The electromagnetic fuel injection valve according to claim 1, wherein the degree of the flat shape of the spray is adjusted. 5. The electromagnetic fuel injection valve according to claim 1, wherein the degree of the flat shape of the spray is adjusted by selecting an injection hole pitch between respective axes of the injection holes.