JPH09242649A - Fuel injection valve for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain good sealing performance at all times by curving at least one of end surfaces moved together with each other of a valve main body and an intermediate disk plate toward an outside in a spheroidal shape, in a device formed in such a constitution that the intermediate disk plate is interposed between a valve body and a valve holding body. SOLUTION: The valve main body 1 of a fuel injection valve is tightly fitted to a valve holding body 5 through an intermediate disk plate 7 by a tightly fitting nut 3. The valve main body 1 is provided with a bag hole 11 extending from an end surface 9 adjacent to the intermediate disk plate 7, and a piston shaped valve member 13 is slidably fitted and inserted therein. A spring chamber 31 opened toward the intermediate disk plate 7 is formed in the valve holding body 5, a valve member 13 is energized by a valve spring 29 housed in the spring chamber 31 so as to seat the valve member 13 to a valve seat 15. In this case, since uniform force is led into a seal surface formed between the intermediate disk plate 7 and the valve main body 1, one of a seal surface 47 which is moved together with each other is curved toward an outside in a spheroidal shape. It is thus possible to ensure good sealing performance.

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 an internal combustion engine, which is provided with a valve main body, in which a valve member is axially slidably guided.
The valve body is axially clamped to the valve holder using a tensioning nut, in which case an intermediate disc is clamped between the valve body and the valve holder. The end surface of the valve is in close contact with the axial end surfaces of the valve body and the valve holder.

[0002]

PRIOR ART German Patent Application Publication No. 440
A fuel injection valve of this type, known from U.S. Pat. No. 8245, has a valve body in which a movable valve member is axially slidably guided,
One end of the valve body projects into the combustion chamber of an internal combustion engine supplied with fuel. The valve body is axially clamped to the valve holder at the end opposite to the combustion chamber using a tension nut, in which case the end face of the valve body opposite to the combustion chamber An intermediate disc is clamped between the lower end surface of the valve holder on the combustion chamber side. The intermediate discs are in close contact with the end faces of the valve body and the valve retainer, respectively, at their axial end faces, and also in axial contact with the end portion of the valve member opposite to the combustion chamber. It has a central through hole for receiving the pressing piece. Furthermore, the intermediate disk is provided with a diagonally extending connection hole, which connects both the valve body and the fuel supply hole in the valve holder.

The valve body is provided with a central blind hole extending from the end surface on the combustion chamber side, and this blind hole forms a spring chamber for receiving a valve spring for loading the valve member in the closing direction. ing.

The sealing of the intermediate disc and the corresponding end face of the valve body or of the valve holder takes place here via the surface pressure at the end face, which surface pressure depends on the tensioning force at the tensioning nut. In this case, the force introduction characteristics in the plane are
Extremely high surface pressure occurs in the radially outer area,
And the force decreases toward the center. This is further aided by the blind holes in the valve holder. This is because no force can be introduced in this range. Due to the introduction of such non-uniform forces, the sealing action at the intermediate disc is impaired in its radially inward extent, so that the known sealing type is
In particular, the high demands of injection valves operating with extremely high injection pressures cannot be fully met.

[0005]

The object of the invention is therefore to improve a fuel injection valve of the type mentioned at the beginning to introduce a uniform force in the cross-section of the seal between the intermediate disc and the valve body. It is to provide a fuel injection valve which can be achieved and thus have a good sealing action.

[0006]

In order to solve this problem, in the structure of the present invention, at least one of the cooperating end faces of the valve body and the intermediate disk is curved outward in a spherical shape. .

[0007]

The fuel injection valve for an internal combustion engine according to the present invention having the above-described structure has the following advantages as compared with the known fuel injection valve. That is, in the fuel injection valve according to the present invention, at least one of the cooperating end faces of the intermediate disc and the valve body has a desired spherical shape, so that the force distribution is uniform in the seal cross section. As a result, even in the radial inner side of the injection valve,
A sufficiently high sealing action can be obtained. Alternatively in this case,
Forming the end face of the intermediate disk outwardly spherical, forming the end face of the valve body opposite to the combustion chamber outwardly spherical, or forming both end faces outwardly spherical It is possible to The apex of the spherically shaped end face, which is arranged at the axis of the injection valve, is above the edge which, when provided with only one curved end face, limits it radially outwardly. It is advantageous for it to project by about 0.001-0.002 mm. If both cooperating end faces are spherically curved outwards, the upward or downward projecting dimension is preferably about 0.0005 to 0.001 mm. In this case, the elastically deformed spherical end face produces a flat sealing surface when the member is in a tightly attached state.

Alternatively, the upper end surface of the intermediate disc on the valve holder side and the lower end surface of the valve holder on the combustion chamber side, which cooperates with this end surface, may be formed in a spherical shape. However, this configuration has a relatively small effect due to the large opening into the spring chamber in the valve holder.

[0009]

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

The fuel injection valve for an internal combustion engine, shown in the assembled state in FIG. 1, has a rotationally symmetrical valve body 1, which uses a tightening nut 3 to make a shaft. Is clamped in the direction to the valve carrier 5, in which case an intermediate disc 7 is clamped between the valve body 1 and the valve carrier 5. A valve body 1 having a free end protruding into a combustion chamber (not shown) of an internal combustion engine supplied with fuel extends from an end face 9 adjacent to the intermediate disk 7 on the side opposite to the combustion chamber. It has a blind hole 11, and a piston-shaped valve member 13 is guided in the blind hole 11 so as to be slidable in the axial direction. In this case, the blind hole 11 is at its closed end,
Forming a valve seat 15 directed inward, this valve seat 1
5 cooperates with a valve sealing surface 19 which is arranged in front of at least one injection port 17 which projects into the combustion chamber of the internal combustion engine and which is arranged on the end face of the valve member 13.

The blind hole 11, which acts as a guide hole for the valve member 13, is enlarged at one location to form a pressure chamber 21, in the region of which the valve member 13 has a pressure shoulder 23. In addition, the valve body 1 and the valve holding body 5 are connected to the connecting pipe piece 27 in the valve holding body 5 through the supply hole 25 penetrating in the axial direction. A fuel injection conduit (not shown) leading to a high-pressure injection pump is connected to the connecting pipe piece 27, and in this case, high-pressure fuel high pressure is alternately supplied from the high-pressure injection pump to the injection valve.

The valve holder 5 is provided with a spring chamber 31 in the form of a central blind hole which opens towards the intermediate disc 7 for receiving the valve spring 29 which is embodied as a compression coil spring. At the bottom of the spring chamber 31, a valve spring 29 is supported at one end via a ring disc 33. At the other end close to the intermediate disc 7, the valve spring 29 presses the valve member 13 under preload via the spring bearing 35, bringing the valve member 13 into contact with the valve seat 15. In this case, the valve member 13 has a pressing piece 37 whose diameter is reduced with respect to the valve member shaft, at the end opposite to the combustion chamber.
7 protrudes through the through hole 39 at the center of the intermediate disk 7.

Supply hole 2 in valve body 1 and valve holder 5
A connecting hole 41 is additionally provided in the intermediate disc 7 in order to connect both parts of the valve 5, and this connecting hole 41 extends obliquely with respect to the valve axis.

The leakage of oil from the spring chamber 31 is performed by the spring chamber 3
1 through a leak oil passage 43, which opens to a leak oil connecting pipe piece 45 provided on the circumferential surface of the valve holder 5.

In order to seal the inner chamber of the injection valve, which is flowed by the fuel, the lower end face 47 of the intermediate disc 7 on the combustion chamber side and the upper end face 49 remote from the combustion chamber are connected to the valve body. 1 in close contact with the end surface 9 of the valve holding body 5 which is remote from the combustion chamber or the lower end surface 51 of the valve holder 5 on the combustion chamber side.

In this case at least one of the cooperating sealing surfaces is spherically curved outwards in order to achieve a uniform introduction of force to the sealing surface between the intermediate disc 7 and the valve body 1. Is configured.

Such a curved construction of the sealing surface
2 to 4 are shown enlarged and simplified as three embodiments.

In the first embodiment shown in FIG. 2, the valve body 1
The end surface on the side opposite to the combustion chamber is flat. The lower end face 4 of the intermediate disc 7 that cooperates with this end face.
7 has a spherical shape that is curved outward (downward), where the apex of the curved surface of the lake is located at the valve member axis. The value of the maximum height X between the edge that limits the spherical end face 47 radially outward and the apex of the spherical end face 47 is in this case approximately 0.001 to 0.0.
02 mm.

In the second embodiment shown in FIG. 3, the lower end face 47 of the intermediate disk 7 is constructed flat and the valve body 1 cooperating with this end face 47 on the side opposite to the combustion chamber. The end surface 9 is configured to be spherically curved toward the outside (upper side). Also in this embodiment, the apex of the spherical end surface 9 extends through the valve axis and the maximum height X of the curved surface is about 0.001 to 0.002 mm.

In the third embodiment shown in FIG. 4, the intermediate disk 7 and the two cooperating end faces 47, 9 of the valve body 1 are shown.
Are both spherically curved, in which case the vertices of the curved surfaces are both located on the valve axis. In this example, however, the value of the maximum height X between the bottom diameter at the radially outer edge and the apex of the curved surface is about 0.0005-0.001 mm.

At the time of assembling the injection valve and when axially tightening the valve body 1 and the intermediate disk 7 with respect to the valve holder 5,
An elastic deformation occurs at the slightly curved end face, which elastically causes the intermediate disc 7 to come into flat contact with the valve body 1 with good sealing. By virtue of the curved or spherical segmented construction of the sealing surface, in a favorable manner, a uniform force introduction is achieved over the entire radial range, such a uniform force introduction providing a sealing action. In particular, the sealing action in the radially inner region is improved compared to known fuel injection valves.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an assembled fuel injection valve.

FIG. 2 is a diagram showing a first embodiment of the fuel injection valve according to the present invention.

FIG. 3 is a diagram showing a second embodiment of the fuel injection valve according to the present invention.

FIG. 4 is a diagram showing a third embodiment of the fuel injection valve according to the present invention.

[Explanation of symbols]

1 valve body, 3 tension nut, 5 valve holder, 7
Intermediate disk, 9 end face, 11 blind hole, 13 valve member, 15 valve seat, 17 injection port, 19 valve sealing surface, 21 pressure chamber, 23 pressure shoulder portion, 25 supply hole, 27 connecting pipe piece, 29 valve spring, 31 spring chamber, 33 ring disc, 35 spring receiver, 37 pressing piece, 39 through hole, 41 connecting hole, 43 leak oil passage, 45 leak oil connecting pipe piece, 47, 49 end face of intermediate disc, 51 valve holder End face of

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor El Nguyen Filitz, Bursa Yesil Jadici, Turkey 27 (72) Inventor Reiner Naumann Bamberg Ober Königstraße 46 (72) Inventor Friedrich Becking Stuttgart Mainz Germany Stranger 27

Claims (9)

[Claims] 1. A fuel injection valve for an internal combustion engine, comprising a valve body (1) in which a valve member (13) is axially slidably guided. The valve body (1) is axially clamped to the valve holder (5) using the tension nut (3), in which case the valve body (1) and the valve holder (5) are An intermediate disc (7) is clamped between and, and the end faces (47, 49) of the intermediate disc (7).
Is in close contact with the axial end surfaces (9, 51) of the valve body (1) and the valve holder (5),
Fuel for an internal combustion engine, characterized in that at least one of the cooperating end faces (9, 47) of the valve body (1) and the intermediate disc (7) is spherically curved outwards. Injection valve. 2. A combustion chamber of an intermediate disc (7), wherein the end face (9) of the valve body (1) opposite to the combustion chamber is formed spherically and cooperates with the end face (9). End face on the lower side (47)
The fuel injection valve according to claim 1, wherein the fuel injection valve is flat. 3. A combustion chamber of an intermediate disc (7), the end face (9) of the valve body (1) facing away from the combustion chamber being flat and cooperating with said end face (9). End face on the lower side (47)
The fuel injection valve according to claim 1, wherein the fuel injection valve has a spherical shape. 4. An end face (9) of the valve body (1) opposite to the combustion chamber, and a lower end face of the intermediate disc (7) on the combustion chamber side cooperating with the end face (9). The fuel injection valve according to claim 1, wherein both (47) and (47) are spherical. 5. The apex of the spherically shaped end face (9, 47) projects about 0.001-0.002 mm above the edge which limits the end face (9, 47) radially outwardly. The fuel injection valve according to claim 2 or 3. 6. Cooperating end faces (9, 4) of spherical construction
Each of the vertices of 7) is approximately 0.0005 above the edge that limits the end face (9, 47) radially outward.
The fuel injection valve according to claim 4, which projects by 0.001 mm. 7. The valve body (1) has an axial blind hole (11) extending from an end face opposite to the combustion chamber for receiving the valve member (13). 11) forms a pressure chamber (21) by enlarging the cross section, and the pressure chamber (21) extends from the end surface (9) opposite to the combustion chamber on the radially outer side of the blind hole (11). 2. The fuel injection valve according to claim 1, wherein the hole (25) is open. 8. An intermediate disc (7) for receiving a pressure piece (37) arranged on the side of the valve member (13) opposite to the combustion chamber, so that the intermediate disc (7) has a blind hole (11) in the valve body (1). Fuel injection valve according to claim 7, characterized in that it has a through hole (39) coaxial with respect to (4) and a connection hole (41) opening to the supply hole (25). 9. A valve spring acting on the valve member (13) in the valve holder (5), which is open to the connection hole (41) in the intermediate disc (7), and another part of the supply hole (25). A central blind hole forming a spring chamber (31) for receiving (29), said blind hole extending from an end face (51) adjacent to the intermediate disc (7), The fuel injection valve according to claim 8.