JP2003184706A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve capable of preventing, the formation of carbon deposit at an injection opening causing a high emission value due to the malfunction of an internal combustion engine and insufficient air-fuel mixture formation. <P>SOLUTION: The injection opening 7 is formed into a tapered shape in a flow direction. A flow-in area of the injection opening 7 is rounded and has wider opening angles than a flow-out area 42. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve for a fuel injection device of an internal combustion engine, which is provided with a valve closing body, and the valve closing body is formed on a valve seat body. A type in which a sealing seat is formed with the seat surface and at least one spray opening is provided, which spray opening is arranged downstream of the seal seat in the flow direction.

[0002]

PRIOR ART German Patent Publication No. 19804
No. 463 discloses a fuel injection system for a mixture compression external ignition internal combustion engine. The fuel injection system has a fuel injection valve, which injects fuel into a combustion chamber formed by a piston-cylinder structure. Further, the fuel injection system is provided with a spark plug protruding into the combustion chamber.
The fuel injection valve is provided with at least one row of a plurality of injection holes distributed over the periphery of the fuel injection valve. By accurately injecting fuel through the injection holes, a jet-guided combustion method is realized by forming a mixture cloud having at least one jet.

Published German Patent No. 1980
A disadvantage of the fuel injection valve known from 4463 is a deposit by coking or a carbon deposit, in particular of the injection opening. This allows
The injection openings become clogged, which significantly reduces the flow through the fuel injector unacceptably. This leads to high emission values due to malfunctioning of the internal combustion engine and insufficient mixture formation.

[0004]

[Patent Document 1] German Patent Publication No. 19804
463 specification

[0005]

SUMMARY OF THE INVENTION The object of the present invention is therefore to improve a fuel injection valve of the type mentioned at the outset, leading to high emissions values due to malfunctions of the internal combustion engine and inadequate mixture formation. An object of the present invention is to provide a fuel injection valve capable of preventing the formation of carbon deposits at the injection opening.

[0006]

In order to solve this problem, in the structure of the present invention, the injection opening is formed in a taper shape in the flow direction, and the inflow region of the injection opening is rounded to flow out. It was designed to have a larger opening angle than the area.

[0007]

With respect to the disadvantages of the known device as described above, the advantage of the fuel injection valve according to the invention with the features of claim 1 is that the injection opening is greater in the inflow region than in the outflow region. It is formed so as to have a diameter. As a result, the diameter of the injection opening is significantly tapered in the direction of fuel flow, so that the flow does not delaminate in the flow passage and therefore no cavitation losses occur.

Advantageous variants of the fuel injection valve according to claim 1 are possible by means of the measures specified in claim 2 and thereafter.

The profile of the cross-sectional contour of the inner wall of the injection opening is preferably parabolic, so that a continuous flow-favorable profile is obtained between the inlet region and the injection opening.

The carbon deposit index and the flow properties are also favorably influenced by the enlarged radii of gyration provided in the inlet region of the injection opening.

The jet openings can advantageously be produced by erosion or another suitable fabrication method, such as laser boring, after which liquid erosion or another flow-guided machining is carried out. The process can be post-processed so that the inner wall of the jet opening is polished and cavitation prone (Kavitati).
onsneigung) decreases.

[0012]

1 is a schematic sectional view showing an embodiment of a fuel injection valve 1 according to the present invention. Fuel injection valve 1
Is configured in the form of a fuel injection valve 1 for a fuel injection device for a mixture compression type external ignition internal combustion engine. This fuel injection valve 1 is suitable for directly injecting fuel into a combustion chamber (not shown) of an internal combustion engine, and a jet guide type (strahlgefuehrt) combustion method (for example, a diesel engine) that is not an external ignition type. Suitable for

The fuel injection valve 1 comprises a nozzle body 2 in which a valve needle 3 is arranged. The valve needle 3 is operatively connected to a valve closing body 4, which cooperates with a valve seat surface 6 arranged on the valve seat body 5 to form a sealing seat. In this embodiment, the fuel injection valve 1 is an inwardly opened fuel injection valve 1 and has at least one injection opening 7.

The valve closing body 4 of the fuel injection valve 1 constructed according to the present invention has a substantially spherical shape. This results in a cardanic valve needle guide that is free of displacement, which valve needle guide provides the correct operating mode of the fuel injection valve 1.

The valve seat body 5 of the fuel injection valve 1 is formed in a substantially pot shape, and the shape thereof serves as a valve needle guide. In this case, the valve seat body 5 is inserted into the injection-side cutout 34 of the nozzle body 2, and the welding seam 35 is formed.
Is connected to the nozzle body 2. The valve closing body 4 and the valve seat body 5 have a sealing function for incoming fuel in connection with the injection opening 7 arranged downstream.

The nozzle body 2 is sealed by a seal 8 to the outer pole 9 of the magnet coil 10. Magnet coil 10
Is accommodated in a coil casing 11 in a capsule shape and is wound around a coil support 12, and the coil support 12 is positioned in contact with the inner pole 13 of the magnet coil 10. The inner pole 13 and the outer pole 9 are separated from each other by a gap 26 and are supported by the connecting component 29. The magnet coil 10 is excited by a current which can be supplied via the electrical conductor 19 via the electrical plug connection 17. The plug-in connection 17 is surrounded by a plastic coating 18, which can be injection molded on the inner pole 13.

The valve needle 3 is guided in a valve needle guide 14, and the valve needle guide 14 is formed in a disc shape. An adjusting disk 15 formed as a pair with this serves to adjust the stroke. A mover 20 is located on the other side of the adjusting disk 15. The mover 20 is connected to the valve needle 3 via a first flange 21 so as to transmit force, and the valve needle 3 is connected to the first flange 21 by a welding seam 22. A return spring 23 is supported on the first flange 21, and the return spring 23 is preloaded or preloaded by the sleeve 24 in the fuel injection valve 1 having such a configuration.

A second flange 31 is arranged on the downstream side of the mover 20, and the second flange 31 functions as a lower mover stopper. This second flange 31 is connected via a welded seam 33 to the valve needle 3 in a force-transmitting manner. An elastic intermediate ring 32 is arranged between the mover 20 and the second flange to cushion the mover impact when the fuel injection valve 1 is closed.

Fuel passages 30a and 30b extend through the valve needle guide 14 and the mover 20. A grinding portion 36 is formed in the valve closing body 4, and the fuel is guided to the seal seat via the grinding portion 36. Fuel is supplied via the central fuel supply 16 and filtered by the filter element 25. The fuel injection valve 1 is sealed to a distributor conduit (not shown) by a seal 28.

According to the invention, the fuel injection valve 1 is arranged in the cutout 34 of the nozzle body 2, for example a welded seam 3
The valve seat body 5, which is connected to the nozzle body 2 by 5, has an injection opening 7 which tapers in the flow direction, the injection opening 7 being rounded in the inflow region 39. This special shape of the injection opening 7 reduces the carbon deposit index, thereby preventing malfunction of the fuel injection valve 1 due to clogging of the injection opening 7 and unacceptable reduction of fuel flow. In addition, the positive influence of the flow characteristics promotes more effective mixture formation and correspondingly lower emission values. An exemplary injection opening 7 of a fuel injection valve 1 equipped with the means according to the invention is shown in FIGS. 2, 3A and 3.
B, which will be described in detail below with reference to the drawings.

In the rest state of the fuel injection valve 1, the first flange 21 provided on the valve needle 3 is provided with a return spring 2
3 against the stroke direction, the valve closing body 4 moves the valve seat 6
It is loaded so as to be kept in close contact with. The mover 20 is mounted on the intermediate ring 32, and the intermediate ring 3
2 is supported by the second flange 31. When the magnet coil 10 is excited, the magnet coil 10 forms a magnetic field, which moves the mover 20 in the stroke direction against the spring force of the return spring 23. At this time, the mover 20 also carries the first flange 21 welded to the valve needle 3 and thus the valve needle 3 in the stroke direction as well. The valve closing body 4, which is operatively connected to the valve needle 3, is lifted up from the valve seat surface 6, whereby fuel is injected at the injection opening 7.

When the coil current is cut off, the mover 20
Is the first flange 21 after the magnetic field has been sufficiently eliminated.
Due to the pressure of the return spring 23 acting on the inner pole 13, the inner pole 13 is separated from the inner pole 13. As a result, the valve needle 3 moves in the direction opposite to the stroke direction. As a result, the valve closing body 4 is seated on the valve seat surface 6, and the fuel injection valve 1 is closed. Mover 20
Mounts on the mover stopper formed by the second flange 31.

FIG. 2 is a cross-sectional view of the downstream portion of the fuel injection valve 1 constructed according to the present invention shown in FIG. 1, that is, a region II shown in FIG. Another construction type of the fuel injection valve 1 was chosen so that the means according to the invention can be clearly illustrated. Consistent components have been given the same reference numbers in all figures.

As already mentioned in connection with FIG. 1, the injection opening 7 formed in the valve seat body 5 is tapered in the direction of fuel flow and is rounded in the inflow region 39. There is. Therefore, the inflow region 39 has a larger diameter than the outflow region 42 formed on the downstream side of the inflow region 39. At that time, the inflow region 39 and the outflow region 4
Since the cross-sectional contour line 43 of the inner wall between the two can extend, for example, in a parabolic shape, the inner wall 41 of the injection opening 7 has
No deviations from the edges or another smooth, flow-friendly shape are produced.

In this embodiment, the fuel injection valve 1 is a fuel injection valve 1 having a plurality of injection openings 7, and these injection openings 7 may be provided at arbitrary points on the valve seat body 5.
Advantageously, the injection openings 7 are arranged on a plurality of circular or oval Lochkreis, which may be concentric or eccentric with respect to each other, or may be parallel or parallel. Rows of straight or curved holes arranged diagonally or offset relative to each other (Lochre
ihe). In that case, the distance between the center points of the holes may be equal or different.
For manufacturing engineering reasons, at least the same hole diameter should be used. The spatial orientation can be different for each hole axis, as shown in FIG. 2 in relation to the two injection openings 7. The production of the injection opening 7 will be described below with reference to FIGS. 3A and 3B.

3A and 3B are schematic cross-sectional views of an exemplary injection opening 7 region of a fuel injection valve 1 constructed in accordance with the present invention, showing two successive processing steps. .

FIG. 3A shows an exemplary injection opening 7 of a fuel injection valve 1 constructed according to the invention after the first processing step.
Is shown. The injection opening 7 may be formed, for example, by erosion processing (Ero).
Dieren) or another suitable manufacturing method.

However, since the surface of the jet opening 7 is relatively rough after the first machining step, the inflow region 39 of the jet opening 7 is formed unfavorably for the flow of fluid, which leads to cavitation tendency. And adversely affect the flow characteristics. This requires post-processing.

FIG. 3B is similar to FIG. 3A and shows an exemplary jet opening 7 after the second processing step. The inflow region 39 is post-machined with respect to its original shape, so that the diameter of the injection openings 7 in the inflow region 39 is larger than in the outflow region 42. This results in an injection opening 7 which is shaped to be flow-friendly. The transition of the inflow edge into the injection opening 7 is characterized by a parabolic-like shape.

The post-processing of the preformed injection opening 7 is preferably carried out by liquid erosion or another flow-guided process, whereby the inner wall 41 of the injection opening 7 is polished. , And this reduces the cavitation tendency. The liquid erosion process is performed by a viscous abrasive, which is used as the inner wall 41.
Can be selected so that its roughness can be polished.

In the inflow region 39 of the injection opening 7, as another means for promoting the flow, a radius of entrainment (Einzgsr) is provided.
adius) 40 is provided, and the pull-in radius is 40
Is the flow separation at the injection opening 7 (Stroemun
It is advantageous to prevent gsabloesung).

Due to the special shape of the injection openings 7, the flow characteristics and the mixture formation can be improved. As a result, the emission value decreases. The diameter of the injection opening 7 is typically 200
Since it is smaller than μm, there is a relatively high risk that the injection opening 7 will become clogged due to coking over time, and thus the flow will be unacceptably significantly restricted. Due to the tapered shape of the injection opening 7, the flow velocity of the fuel increases in the flow direction, which prevents flow separation in the injection opening 7. The jet openings 7 are protected from coking by the adjacent flow, so that the jet openings 7 are not blocked by coked deposits or carbon deposits.

The present invention is not limited to the illustrated embodiment, and for example, arbitrarily arranged injection openings 7, a plurality of conical extending injection openings 7, and a plurality of inwardly opening holes. -It can be used for any structure type of the fuel injection valve 1. Similarly, the present invention can be used in self-igniting internal combustion engines (eg diesel engines).

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an embodiment of a fuel injection valve constructed according to the present invention, shown in overall view.

FIG. 2 is a schematic cross-sectional view of a fuel injection valve configured according to the present invention, which corresponds to another modified embodiment, in a region indicated by reference numeral II in FIG. 1.

3A is an enlarged view of an exemplary injection opening of the fuel injection valve according to the present invention shown in FIG. 2 after a first processing step.

3B is an enlarged view of an exemplary injection opening of the fuel injector according to the present invention shown in FIG. 2 after a second processing step.

[Explanation of symbols]

1 fuel injection valve, 2 nozzle body, 3 valve needle,
4 valve closing body, 5 valve seat body, 6 valve seat surface, 7 injection opening, 8 seal, 9 outer pole, 10 magnet coil, 11 coil casing, 12 coil support, 13 inner pole, 14 valve needle guide, 15
Adjusting disc, 16 fuel supply part, 17 plug-in connection part, 18 plastic covering part, 19 lead wire, 2
0 mover, 21 first flange, 22 weld seam, 23 return spring, 24 sleeve, 25
Filter element, 26 gap, 28 seal, 29 connecting component, 30a fuel passage, 3
0b Fuel passage, 31 2nd flange, 32 Intermediate ring, 33 Weld seam, 34 Notch, 35
Weld seam, 36 grinding section, 39 inflow area,
40 retraction radius, 41 inner wall, 42 outflow area,
43 Cross-section contour line

Continued front page    (72) Inventor Joseph Pickel             Federal Republic of Germany Heiligenstadt               Geisdorf 7 (72) Inventor Fridlin Zeck             Federal Republic of Germany Scheritz-Demel             Sdorf Beno-Schmidt-Streller             38 (72) Inventor Jürgen Schubert             Bamberg Karl, Germany             My Strasse 18 (72) Inventor Friedrich Weiss             Bamberg Anva, Federal Republic of Germany             Understraße 5 b (72) Inventor Matthias Klinger             Spain Apartament of Madrid             35005 F term (reference) 3G066 AA01 AA07 AB02 BA32 CC01                       CC05U CC10 CC14 CC21

Claims (5)

[Claims] 1. A fuel injection valve (1) for a fuel injection device of an internal combustion engine, comprising a valve closing body (4), the valve closing body (4) comprising a valve seat body (5). ), Which forms a seal seat with the valve seat surface (6) and which is provided with at least one injection opening (7), which injection opening (7) is downstream of the seal seat in the flow direction. In the type arranged on the side, the injection opening (7) is shaped to taper in the flow direction, the inflow area (39) of the injection opening (7) is rounded, and the outflow area ( 42) A fuel injection valve having an opening angle larger than 42). 2. Contour line (43) of the injection opening (7)
2. The fuel injection valve according to claim 1, wherein the fuel injection valve extends parabolically between the inflow region (39) and the outflow region (42). 3. The fuel injection valve according to claim 1, wherein the injection opening (7) is manufactured by erosion processing. 4. The fuel injection valve according to claim 1, wherein a lead-in radius (40) is formed in the inflow region (39) of the injection opening (7). 5. The fuel injection valve according to claim 4, wherein the injection opening (7) is post-processed by a flow-guided process.