JPH0299756A - Electromagnetic type fuel injection valve for internal combustion engine - Google Patents

Abstract

PURPOSE:To permit the fuel atomization and facilitate the working of a plate orifice by installing the plate-shaped plate orifice having an injection hole which is formed by the superposition of a through hole and an opened port part and installing a needle which is lifted by a solenoid. CONSTITUTION:A body 6 has an opened port part 8 at the top edge center part, and a seating surface 9 is formed on the upstream side of the opened port part 8. A plate orifice 13 has four through holes 4 which partially communicate to the opened port part 8. Since an injection hole 15 is formed into a shape which is formed by dividing a part of each through hole 14, the diameter of the through hole 14 is made considerably large in comparison with the opened port area of the injection hole 15. Therefore, working of the plate orifice can be carried out easily, and the opened port area of the injection hole can be made sufficiently large, and the fuel atomization is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electromagnetic fuel injection valve used in an internal combustion engine such as a gasoline engine, and particularly to a plate orifice type fuel injection valve.

2. Description of the Related Art For example, fuel injection valves for gasoline engines are often of the so-called bottle type, in which a single nozzle hole is opened and closed by a needle having a bottle portion at the tip.

In contrast, in recent years, a plate orifice type fuel injection valve using a plate-like plate orifice has been proposed in SAE Vapor 870124 [Bosch Injector New Development]. This is the 9th
As shown in the figure, a plate orifice 24 through which a plurality of nozzle holes 23 are formed is arranged in front of the opening 22 through which the needle 21 opens and closes, so that a plurality of spray lines can be formed through each nozzle hole 23. By slightly inclining each nozzle hole 23 outward, it is possible to perform fuel injection that is widely diffused as a whole. Furthermore, by dividing the plurality of injection holes 23 into two groups and slanting each group left and right, two-way injection suitable for a two-valve intake engine can be realized.

Problems to be Solved by the Invention However, in such plate orifice type fuel injection valves, the atomization of fuel droplets is generally poorer than in the bottle type in which the fuel can be diffused by the bottle part. That is, in order to reduce the diameter of the fuel particles coming out of the nozzle holes 23, it is necessary to make each nozzle hole 23 even smaller in diameter and at the same time increase the number of nozzle holes 23. The increase is limited by processing technology. Furthermore, if the shape of each nozzle hole 23 is not a perfect circle but a flat shape similar to a slit, the contact area between the surrounding air and the fuel will increase and fuel atomization will be promoted. It is extremely difficult to process a small nozzle hole into such a flat shape. Therefore, sufficient atomization of the fuel cannot be achieved.

Means for Solving the Problems An electromagnetic fuel injection valve for an internal combustion engine according to the present invention includes a body having an opening at the center of the tip and a seating surface formed on the upstream side of the opening, and a body at the tip of the body. A plate-like plate orifice is arranged on the surface and has a plurality of through holes, and forms a nozzle hole by overlapping the through holes and the opening, and is slidably fitted into the center of the body. death,
It is configured to include a needle that is seated on the seating surface and lifted by a solenoid. Alternatively, it has a plurality of plate orifices, and the injection holes are formed by overlapping through holes of each plate orifice.

Effect: In the above configuration, the substantial nozzle hole shape is determined by the overlap between the opening of the body and the through hole of the plate orifice, or the overlap of the through holes of a plurality of plate orifices. Therefore, even if the through hole itself is large, the actual nozzle area can be made sufficiently small.
Moreover, a desired nozzle hole shape can be easily obtained.

Embodiment FIG. 1 is a sectional view showing the structure of an electromagnetic fuel injection valve according to the present invention.

In the same figure, l is equipped with a cylindrical solenoid 2 inside, and an injection valve holder with a fuel inlet 3h (provided on the side), 4 is attached to the base end of this injection valve holder l, and a connector part 5 6 is a body held at the tip of the injection valve holder I, and 7 is a stopper interposed between the body 6 and the injection valve holder I.

The bipedal body 6 has a relatively large perfectly circular opening 8 at the center of its tip, and a conical seating surface 9 is formed upstream of this opening 8.

A needle IO is slidably fitted into the center of the body 6. This needle 10 is always open and urged downward by a coil spring 11 disposed within the injection valve holder l, and its tip portion seats on the seating surface 9 to seal the opening 8. When the bipedal solenoid 2 is energized, it lifts upward. The sliding stroke of the needle 10 is regulated to a constant amount by the stopper 7.

A cylindrical protector 12 is fitted and fixed to the distal end of the body 6, and a plate-shaped plate orifice 1 is provided between the protector 12 and the distal end surface of the body 6.
3 is clamped and fixed.

This plate orifice 13 is arranged along the front end surface of the body 6 so as to close the opening 8 of the body 6, and is partially connected to the opening 8 as shown in FIG. It is equipped with four communicating through holes (4).

As shown in FIG. 4, each of the through holes 14 has a perfect circular shape, and is arranged so as to be located at the apex of a square. Further, the four through holes 14 are divided into two groups of two, and the through holes I4 of each group are formed through the through holes with a slight inclination to the left and right.

As shown in FIGS. 2 and 3, the through hole 14 is located on the periphery of the opening 8 of the body 6, and is partially covered by the front end surface of the body 6. That is, the through hole 1
4 and the above-mentioned opening 8, a substantial nozzle hole ■5
are divided into sections. As is clear from FIG. 3, these four nozzle holes 15 all have a flat, substantially spindle shape.

In the fuel injection valve configured as described above, when the needle 10 lifts, fuel is injected from the opening 8 through each injection hole 15. Since each spray flows out along the slope of the through hole 14 of the plate orifice 13, a spray shape is obtained in which two strips are branched in two directions, and the intake air 2
Two-way injection suitable for valve-type engines can be realized.

Here, since the nozzle holes 15 are formed in a shape that partitions a part of each through-hole 14, the diameter of the through-hole 14 is very large compared to the opening area of the nozzle hole 15. Therefore, the processing becomes extremely easy, and the opening area of the nozzle hole 15 can be made sufficiently small to achieve fuel atomization.

Furthermore, since the nozzle hole 15 has a lower shape as shown in FIG. 3, the contact area between the surrounding air and the fuel increases, compared to a perfectly circular nozzle hole with the same opening area. , the fuel particle size can be made even smaller.

Next, FIGS. 5 to 8 show an example in which a plurality of plate orifices are used.

In this embodiment, a first plate orifice 16 and a second plate orifice 17 are disposed overlappingly between the front end surface of the body 6 and the protector 12. As shown in FIG. 6, the first plate orifice 16 located on the body 6 side has one perfectly circular through hole 18 formed in its center. The second plate orifice 17 located on the protector 12 side has four relatively wide arc-shaped through holes as shown in FIG. 9 is formed. Therefore, when the two are overlapped, as shown in FIG. 8, four very narrow arcuate nozzle holes 20 are formed. Incidentally, if the inner edge of the through hole 19 is machined with an appropriate inclination, it is possible to easily realize bidirectional injection or annular pattern injection similar to the embodiment described above.

Effects of the Invention As is clear from the above explanation, according to the electromagnetic fuel injection valve for an internal combustion engine according to the present invention, the through hole formed in the plate orifice itself can be reduced in size without being extremely small. A sufficiently small opening area can be secured, fuel atomization can be achieved, and the plate orifice can be easily machined. Further, the nozzle hole shape can be made into any shape other than a perfect circle, thereby making it possible to further reduce the fuel particle size.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a fuel injection valve according to the present invention, FIG. 2 is an enlarged cross-sectional view of its main parts, and FIG. 4 is a plan view of only the plate orifice, FIG. 5 is a sectional view of the main part showing a different embodiment of the invention, FIG. 6 is a plan view of the first plate orifice, and FIG. 7 is a plan view of the first plate orifice. A plan view of the second plate orifice, FIG. 8 is a plan view of the main part showing both plate orifices overlapped, and FIG. 9 is a sectional view showing the main part of a conventional fuel injection valve. 6... Body, 8... Opening, 10... Needle, 13... Plate orifice, 14... Through hole,
15... Nozzle hole, 16... First plate orifice,
17...Second plate orifice, 18.19...
Through hole, 20... nozzle hole. Figure 1 Figure 5 16 - First plate orifice 17 - Second plate orifice 18.19 Through hole Figure 2 Figure 3 Figure 4 Figure 15 - Nozzle hole

Claims (2)

[Claims] (1) A body having an opening in the center of the tip and a seating surface formed on the upstream side of the opening; A plate-like plate orifice that forms a nozzle hole by overlapping the hole and the opening, and a needle that is slidably fitted into the center of the body, is seated on the seating surface, and is lifted by a solenoid. Electromagnetic fuel injection valve for internal combustion engines. (2) a body having an opening in the center of the tip and a seating surface formed on the upstream side of the opening; and a body disposed on top of each other on the tip surface of the body, each having a through hole; and a plurality of plate-shaped plate orifices that form a nozzle hole by overlapping each other's through holes, and a needle that is slidably fitted into the center of the body, is seated on the seating surface, and is lifted by a solenoid. An electromagnetic fuel injection valve for an internal combustion engine.