EP3002447A1 - Fuel injection device - Google Patents

Abstract

Fuel injection device (100) for injecting fuel into a combustion chamber of an internal combustion engine having a first component (1) and a second component (2; 2 ') which are axially screwed together by a clamping nut (5), wherein the clamping nut (5) in is in threaded engagement with the first component (1), so that a first end face (1a) formed on the first component (1) is pressed together with a second end face (2a, 2a ') formed on the second component (2; At least the first end face (1a) is structured in such a way that no twisting of the first component (1) and the second component (2, 2 ') takes place during the tightening of the clamping nut (5).

Description

The invention relates to a fuel injection device for injecting fuel into the combustion chamber of an internal combustion engine.

State of the art

From the publication DE 10 2011 078 353 A1 a fuel injector for injecting fuel into the combustion chamber of an internal combustion engine is known, which comprises a valve housing and a nozzle body, which are clamped by means of a clamping nut against each other. In order to prevent twisting of the valve housing and nozzle body when tightening the clamping nut, a fixing pin or locking pin is arranged in facing blind holes of valve housing and nozzle body.

The torque transmission between the valve housing and the nozzle body of the known Kraftstoffinjektors takes place to a large extent on the locking pin, which is thus exposed to very large shear forces and shear stresses. Consequently, the strength of the securing pin limits the maximum permissible tightening torque of the clamping nut and thus also the maximum permissible nominal pressure of the fuel injector. Furthermore, the locking pin or the locking pins is expensive.

Disclosure of the invention

In the fuel injection device of the invention, the allowable nominal pressure is increased by the maximum allowable torque - without causing a relative rotation of the components to be screwed - is increased for the clamping nut by increasing the coefficient of friction between the components to be screwed; the hold-down force of the assembly tool on the components to be screwed during tightening the nut need not be increased, but can even be lowered. The invention is not limited to a fuel injector, but is generally suitable for a fuel injector for injecting fuel into the combustion chamber of an internal combustion engine.

For this purpose, the fuel injection device according to the invention comprises a first component and a second component, which are screwed axially against each other by a clamping nut, wherein the clamping nut is in a threaded engagement with the first component, so that a first component formed on the first end face with a formed on the second component second End face is compressed. At least the first end face is structured in such a way that no twisting of the first component and the second component occurs during tightening of the clamping nut. The structuring increases the coefficient of friction, especially the static coefficient of friction, in contact of the first component with the second component, thereby increasing the maximum transferable tightening torque of the clamping nut - with a constant hold-down force on the first and second component - compared with an unstructured end face, without the first Rotate component and the second component against each other.

In an advantageous embodiment, the structuring extends over the entire first end face. The maximum torque transmission from the first component to the second component or vice versa is thereby distributed over the largest possible area; their increase due to the structuring is therefore particularly large.

In another advantageous embodiment, the structuring extends over annular sector-shaped segments of the first end face. The annular sector shaped segments are in the form of cake pieces with an optional centric one Bore, eg to guide a valve needle, in the "cake center". They are used particularly advantageously when high-pressure bores pass through the first end face. The high-pressure bores are then sealed in contact of the first end face and the second end face via annular sector-shaped sealing surfaces. In a first variant, the sealing surfaces are structured, so that both sealed over these surfaces and a large part of the tightening torque is transmitted. In a second variant, the two functions of sealing and torque transmission are separated: the torque transmission takes place via the structured annular sector-shaped segments and the seal via the segments lying between them, which are also ring sector-shaped. Preferably, three structured annular sector-shaped segments are formed alternately with three unstructured annular sector-shaped segments, wherein a segment is formed in each case over 60 ° of the end face.

In another advantageous embodiment, the structuring extends over an annular segment of the first end face. High-pressure bores which pass through the first end face can also be well sealed by this design: Analogously to the preceding embodiment, the high-pressure bores are either all in the structured annular segment or all in one or more unstructured annular segments of the first end face. In both embodiments, a particularly effective sealing edge can be formed at the boundary of the structured annular segment to an unstructured annular segment for sealing.

In another advantageous embodiment, structured annular sector-shaped segments can be combined with structured annular segments, either additively as a union of all structured segments, or exclusively as an intersection of the structures of annular sector-shaped segments with annular segments.

In advantageous developments of the foregoing, the first face is structured by R ≤ _Z ≤ 16 microns has an average surface roughness of 6 microns. This average roughness R _z is higher than the usual roughness values of the first end face and the second end face, thereby also the coefficient of friction between the first end face and the second end face being higher in comparison to unstructured end faces.

Advantageously, the first end face has grooves as a structure. These can be applied specifically with the processing methods grinding and turning targeted in a simple production machining. The grooves may be both of a microscopic nature to increase the roughness and more macroscopic way to increase the waviness of the first end face. In both cases, the static coefficient of friction between the first end face and the second end face is increased. Ridges which increase the waviness on the first end face are particularly advantageous if corresponding grooves in the negative form are formed on the second end face and vice versa. The grooves of the first and second end surfaces then engage with each other, resulting in a significant increase in the transmittable torque of the first component to second component result. The laser-structuring and embossing processes can then be used particularly advantageously.

In an advantageous embodiment, the grooves run in two different main directions, so that a cross-cut results. As a result, the first end surface is heavily roughened, so that a comparatively large mean roughness R _Z results, which is also almost independent of direction. Thus, the coefficient of friction is almost independent of the direction of rotation or screwing. Advantageously, the cross-cut is used in grooves R of the microscopic type, since a counter-grinding on the second face in negative form manufacturing technology is not implement.

In advantageous embodiments of the fuel injection device according to the invention, the second end face is structured. In the case of microscopic structuring, the averaged roughness depths R _Z of the first end face and the second end face are comparatively high, whereby the coefficient of adhesion increases again compared to a tribological system with only one structured end face, since the roughness peaks of the opposite end faces interlock with one another in the case of two structured end faces , In the case of macroscopic structures, the first end face is preferably and the second end face are each patterned negatively relative to each other so that the structures of the two end faces are in engagement with one another. As a result, a kind of positive engagement of the first component to the second component is formed for the torque transmission.

In an advantageous development of the fuel injection device according to the invention a locking pin is arranged as an additional anti-rotation between the first component and the second component. Especially with the use of microscopic structures, this can be necessary with extreme increase of the tightening torque of the clamping nut. This can be done a further increase in the sealed nominal pressures within the fuel injection device. Furthermore, it is entirely possible to dispense with a hold-down force on the first and second component in this embodiment. In addition, the locking pin serves as an assembly aid for positioning of the first component and the second component; Of course, several locking pins can be used for this purpose.

In advantageous embodiments, the first component, the second component and the clamping nut have a substantially axially symmetrical shape. Especially when the clamping nut is designed as a kind of union nut, a coaxial alignment of the first component to second component can be designed in a relatively simple form.

In an advantageous embodiment, the clamping nut is applied to a shoulder of the second component and slides when tightening on this. A direct power flow from the clamping nut to the first component and the second component is ensured. The sliding of the clamping nut on the shoulder of the second component takes place to the same extent as the screwing into the thread of the first component, so that there is no relative rotation of the first component to second component. For this purpose, the transmittable torque between the clamping nut and the second component must be smaller than the transmittable torque between the second component and the first component. Accordingly, preferably, the surface of the shoulder, which cooperates with the clamping nut, unstructured and has a small average surface roughness R _Z as the first end face and / or the second end face. Optionally, a coating can be applied to the shoulder, which has a low sliding friction result.

In another advantageous embodiment of the fuel injection device, a third component is arranged on the second component opposite the first component. A third end face formed on the third component is pressed together with a further end face formed on the second component, wherein the clamping nut rests against a shoulder of the third component and slides on it when tightened. As a result, three components, namely the first, the second and the third component, are pressed together by the clamping nut. Preferably, such an embodiment is used to more advantageously arrange functions of the fuel injector in the additional third component or to integrate additional functions for the fuel injector.

Advantageously, in a development, the third end face and / or the further end face are structured. This results in an increase in the torque transfer torque-proof both between the first and second as well as between the second and third component.

In advantageous embodiments of the fuel injection device according to the invention, the structuring by sputtering, embossing, etching, sandblasting or laser structuring is applied. In this case, preferably microscopic structures are applied by the surface treatments sputtering, etching or sandblasting and macroscopic structuring by the surface treatment processes embossing or laser structuring.

In an advantageous embodiment, the fuel injection device is a fuel injector. Especially with fuel injectors an increase in the permissible torque of a clamping nut without simultaneous rotation of the braced components is required because for future applications, the sealed pressures of the fuel within the fuel injector continue to rise.

drawings

• Fig.1 shows schematically a fuel injection device according to the invention, wherein only the essential areas are shown.
• Fig.2 shows the section AA the Fig.1 in one embodiment.
• Figure 3 shows the section AA the Fig.1 in a further embodiment.
• Figure 4 shows the section AA the Fig.1 in a further embodiment.
• Figure 5 shows schematically a further embodiment of the fuel injection device according to the invention, wherein only the essential areas are shown.
• Figure 6 shows the section BB of Figure 5 in one embodiment.
• Figure 7 shows a part of the Fig.2 and the Figure 6 in a further embodiment.
• Figure 8a schematically shows a section of another embodiment of the fuel injection device according to the invention, wherein only the essential areas are shown.
• 8B shows the section CC the Figure 8a an embodiment.
• Figure 9 shows schematically a further embodiment of the fuel injection device according to the invention, wherein only the essential areas are shown.

description

Fig.1 shows a fuel injection device 100 for injecting fuel into the combustion chamber of an internal combustion engine, wherein only the essential parts for the present invention are shown. The fuel injection device 100 may be, for example, a fuel injector, as used in a common rail system.

The fuel injection device 100 comprises a first component 1 and a second component 2, which are screwed against one another with a clamping nut 5, so that a first end surface 1a formed on the first component 1 is pressed with a second end surface 2a formed on the second component 2. The clamping nut 5 is in threaded engagement with a thread formed on the first component 1 and abuts against a shoulder 2s of the second component 2. When tightening the nut 5, this slides on the shoulder from 2s.

The first component 1 and the second component 2 are to be screwed tightly against each other by the clamping nut 5. During the tightening process twisting of the two components 1, 2 against each other should be prevented. This is done with a pressure force by the clamping nut 5 and / or an external hold down force of a mounting tool on the two components 1, 2. An increase in the transmittable torque between the two components 1, 2 - and thus a higher security against rotation - is increased by an increase the coefficient of friction of the first end face 1a and / or the second end face 2a, or also achieved by positive closures between the first end face 1a and the second end face 2a. As a result, the coefficient of friction between them increases such that the transmittable transverse force or the transmittable torque is increased in such a way that a rotation of the first component 1 and the second component 2 during the tightening of the clamping nut 5 is prevented. As a result, either the hold-down force can be reduced by a hold-down device, not shown on the first component 1 and second component 2 during tightening of the clamping nut 5 or the tightening torque of the clamping nut 5 can be increased at a constant hold-down force.

First component 1 and second component 2 may be, for example, components of a fuel injector, such as injector body and nozzle body. For this case, the second component 2 has injection openings 20. It is, however conceivable that other components, such as a valve plate or a throttle plate, are screwed on the clamping nut 5, so that there are additional contact surfaces, which also have structuring, so that there is a rotation of the components against each other prevented; However, such an embodiment is in Figure 5 described in more detail.

Fig.2 shows the section AA the Fig.1 , That is, the contact plane from the first end face 1a to the second end face 2a in one embodiment. Shown are the first component 1 and the clamping nut 5. The first component 1 has an exemplary bore 1c, which also cuts through the first end face 1a, as used for example for performing a valve needle. There are also other holes, for example, designed as inlet throttle or as a drain throttle holes, conceivable that cut through the first end face 1a. Such holes are well known from the prior art.

In the Fig.2 Structuring shown extends over the entire first end face 1a. The structuring can thus be done comparatively simply by a surface treatment which does not require the removal of individual parts of the first end face 1a. In other embodiments, the second end face 2 a may also be structured instead of or in addition to the first end face 1 a.

Figure 3 shows the section AA the Fig.1 a further embodiment. In this embodiment, the first end face 1a is cut through by two bores 1c and 1d, wherein the first bore 1c is arranged centrally. The first end face 1a is divided from outside to inside into three annular segments 1n1, 1r and 1n2, wherein the outer segment 1n1 and the inner segment 1n2 are not structured while the central annular segment 1r is structured.

In various applications of the embodiment of the Figure 3 the structured annular segment 1r can either be a sealing surface of the first component 1 to the second component 2, or else a surface which adjoins an unstructured sealing surface; in the second case would be the sealing surface then either the outer segment 1n1 or the inner segment 1n2, in which case, of course, the holes 1c and 1d must be such that they are sealed over the sealing surface in the sectional plane AA.

In an embodiment according to the Figure 3 For sealing, a particularly effective sealing edge can be formed at the boundary of the structured annular segment 1r to form an unstructured annular segment, ie either 1n1 or 1n2. This is achieved, for example, in that the first end face 1a is not made planar but convex, or in that the structured annular segment 1r has a very small angle (approx. 1n) to the unstructured annular segment adjacent to it, ie 1n1 and / or 1n2. 0.5 °).

Figure 4 shows the section AA the Fig.1 a further embodiment. In this embodiment, the first end face 1a of three holes 1c, 1d and 1e passes through, wherein the first bore 1c is arranged centrally. Unlike in the previous embodiment according to Figure 3 the first end face 1a is not divided into annular segments, but in segments of an annular sector, that is, in cake-segment-shaped segments which meet in the central bore 1c. In the illustrated embodiment, three annular sector-shaped segments 1k are structured and three further annular sector-shaped segments 1n are not structured, wherein circumferentially one structured segment 1k follows an unstructured segment 1n and the segments each comprise 60 °. In similar embodiments, of course, segmentations are conceivable that include a different number of segments and / or other segment angle.

• In einer ersten Unterausführung werden die kreisringförmigen Segmente 1r und die ringsektorförmigen Segmente 1k additiv überlagert, so dass sich eine Vereinigungsmenge der strukturierten Flächen ergibt. Dadurch kann z.B. die zentrische Bohrung 1c besser abgedichtet werden, wenn die Abdichtung über die strukturierte Fläche erfolgt.
• In einer zweiten Unterausführung werden die kreisringförmigen Segmente 1r und die ringsektorförmigen Segmente 1k exklusiv überlagert, so dass sich für dieses Ausführungsbeispiel eine Schnittmenge der strukturierten Flächen aus den Ausführungsbeispielen von Fig.3 und Fig.4 ergibt. Dadurch kann z.B. die zentrische Bohrung 1c besser abgedichtet werden, wenn die Abdichtung über die nichtstrukturierte Fläche erfolgt.

Advantageously, the noncentric bores 1d and 1e are each arranged in a structured annular sector-shaped segment 1k, in the event that is sealed over the structured annular sector-shaped segments 1k, or the non-centric bores 1d and 1e are each arranged in an unstructured annular sector-shaped segment 1n, for the case that is sealed over the unstructured annular sector-shaped segments 1n. Especially if the first end face 1a is processed by surface treatment methods such as laser structuring or embossing, it is also possible to apply arbitrarily complex segmentations. For example, it is conceivable the execution of Figure 3 with the Figure 4 to combine:

• In a first sub-embodiment, the annular segments 1r and the annular sector-shaped segments 1k are additively superimposed, so that a combination of the structured surfaces results. As a result, for example, the central bore 1c can be better sealed if the sealing takes place over the structured surface.
• In a second sub-embodiment, the annular segments 1r and the ring-sector-shaped segments 1k are superimposed exclusively, so that for this exemplary embodiment an intersection of the structured surfaces from the exemplary embodiments of FIG Fig.3 and Fig.4 results. As a result, for example, the central bore 1c can be better sealed if the sealing takes place over the non-structured surface.

Also to the embodiments of the Fig.3 and Fig.4 Variants are conceivable in which the second end face 2a is structured instead of or in addition to the first end face 1a.

• Die Spannmutter 5 steht im Gewindeeingriff mit dem ersten Bauteil1.
• Das erste Bauteil 1 wirkt an der ersten Stirnfläche 1a mit dem zweiten Bauteil 2' an der zweiten Stirnfläche 2a' zusammen.
• Das zweite Bauteil 2' wirkt außerdem an einer an ihm ausgebildeten weiteren Stirnfläche 2b', die der zweiten Stirnfläche 2a' entgegengesetzt angeordnet ist, mit dem dritten Bauteil 3 an einer an diesem ausgebildeten dritten Stirnfläche 3a zusammen.
• Die Spannmutter 5 steht im Eingriff mit einer am dritten Bauteil ausgebildeten Schulter 3s, wobei die Schulter 3s der dritten Stirnfläche 3a entgegengesetzt angeordnet ist.

Figure 5 schematically shows a further embodiment of the fuel injection device 100 according to the invention, in which an additional third component 3 is clamped to the first component 1 and the second component 2 'via the clamping nut 5. In this case, the second component 2 'is arranged between the first component 1 and the third component 3. The power flow of the threaded bandage is as follows:

• The clamping nut 5 is in threaded engagement with the first Bauteil1.
• The first component 1 acts on the first end face 1a with the second component 2 'on the second end face 2a' together.
• The second component 2 'also cooperates with the third component 3 on a third end face 2 b' formed on it, which is arranged opposite the second end face 2 a ', on a third end face 3 a formed on the latter.
• The clamping nut 5 is engaged with a shoulder 3s formed on the third component, the shoulder 3s being arranged opposite to the third end face 3a.

• Dargestellt sind das zweite Bauteil 2' und die Spannmutter 5. Das zweite Bauteil 2' weist eine beispielhafte Bohrung 2c' auf, die auch die weitere Stirnfläche 2b' durchsetzt. Es sind auch weitere Bohrungen, beispielweise als Zulaufdrossel oder als Ablaufdrossel ausgebildete Bohrungen, denkbar, die die weitere Stirnfläche 2b' durchsetzen. Fig.6 zeigt schematisch eine Strukturierung, die sich über die gesamte weitere Stirnfläche 2b' erstreckt. Jedoch sind auch für die weitere Stirnfläche 2b' andere Strukturierungen möglich, die beispielsweise analog ausgeführt sind zu den Ausführungsbeispielen der Fig.3 und Fig.4 für die erste Stirnfläche 1a.

Figure 6 shows the section BB of Figure 5 in one embodiment. In this case, the section BB is analogous to the section AA of Fig.2 but refers to the second component 2 'in the contact plane to the third component 3:

• Shown are the second component 2 'and the clamping nut 5. The second component 2' has an exemplary bore 2c ', which also passes through the further end face 2b'. There are also other holes, for example, designed as inlet throttle or as a drain throttle holes, conceivable that pass through the further end face 2 b '. Figure 6 schematically shows a structuring, which extends over the entire further end face 2b '. However, other structures are also possible for the further end face 2b ', which, for example, are analogous to the exemplary embodiments of FIGS Fig.3 and Fig.4 for the first end face 1a.

Figure 7 shows a section of a structured end face, as for example in the Fig.2 and the Figure 6 is marked. In general, this segment is possible for each structured segment and is intended to represent only one embodiment of the structuring. The structuring consists of individual grooves R, as they are applied for example in the surface treatment via a grinding process. In the in Figure 7 As shown, the grooves R are roughly in two different main directions R1 and R2, which are largely perpendicular to each other, so that there is essentially a kind of cross-section as a structure.

Figure 8a schematically shows a section of another embodiment of the fuel injection device according to the invention, in which the first component 1 with the second component 2; 2 'is braced, wherein the clamping nut is not shown.

In this embodiment, the structuring of the first end face 1a and the second end face 2a; 2a 'comparatively large: on the first end face 1a receiving grooves 1p are applied and on the second end face to Precise keyway elevations 2p; 2p ', which preferably have a height h of 25 microns to 63 microns, each with a feather key 2p; 2p 'is disposed in a receiving groove 1p. When tightening the clamping nut, the feather key elevations 2p act; 2p 'like many small feather keys and are therefore particularly well suited for torque transmission. At higher heights of structuring than 63 μm, the tolerance of the assembly is negatively influenced with respect to parallelism, but at smaller heights than 25 μm, the effect of the positive connection is too low.

8B shows the section CC the Figure 8a , ie a plan view of the second end face 2a; 2a 'of the second component 2; 2 'in one embodiment. In this embodiment, the second component has three holes 2c; 2c ', 2d; 2d 'and 2e; 2e ', which are sketched by way of example as pressure-loaded bores or guide bores. On the second end face 2a; 2a 'are a plurality of keyways 2p; 2p ', which in this embodiment have a triangular shape in plan view. Of course, other shapes such as circular or rectangular shape can be used. The keyway elevations 2p; 2p 'are advantageously arranged so that they also serve as an assembly aid.

In particular, the surface processing methods embossing and laser structuring are suitable for applying to the two end faces 1a and 2a; 2a 'receiving grooves 1p and keyway elevations 2p; 2p 'apply. The tolerances should be chosen so that the side surfaces of grooves 1p and keyways 2p; 2p 'get in good contact with each other, so are relatively tight tolerated. In the axial direction of the components is a contact between receiving grooves 1p and keyholes 2p; 2p 'be avoided, so that the axial biasing force between the first component 1 and second component 2; 2 'on the two end faces 1a and 2a; 2a 'outside the receiving grooves 1p and keyway elevations 2p; 2p 'works.

• Eine erste Stiftbohrung 12 ist im ersten Bauteil 1 in axialer Richtung als Sacklochbohrung von der ersten Stirnfläche 1a ausgehend ausgebildet.
• Eine zweite Stiftbohrung 22 ist der ersten Stiftbohrung 12 gegenüberliegend im zweiten Bauteil 2 in axialer Richtung als Sacklochbohrung von der zweiten Stirnfläche 2a ausgehend ausgebildet.

Die Anordnung eines oder mehrerer Sicherungsstifte 7 erhöht dadurch das übertragbare Drehmoment von erstem Bauteil 1 zu zweitem Bauteil 2 noch einmal deutlich, ohne dass sich das zweite Bauteil 2 gegenüber dem ersten Bauteil 1 beim Anziehen der Spannmutter verdreht. Weiterhin kann der mindestens eine Sicherungsstift 7 als Montagehilfe verwendet werden, so dass erstes Bauteil 1 und zweites Bauteil 2 exakt zueinander positioniert werden. Figure 9 shows a further embodiment of the fuel injection device according to the invention. This embodiment is that of Fig.1 very similar, ie with a structured first end face 1a and a second end face 2a, which can optionally also be structured. When Mounting aid and / or to further increase the transmittable torque between the first component 1 and second component 2 and to reduce the hold-down force on the two components 1, 2 during tightening of the clamping nut 5 is at least one locking pin 7 between the first component 1 and second component. 2 arranged in holes designed for this purpose:

• A first pin bore 12 is formed in the first component 1 in the axial direction as a blind hole starting from the first end face 1a.
• A second pin bore 22 is formed opposite the first pin hole 12 in the second component 2 in the axial direction as a blind hole starting from the second end face 2a.

The arrangement of one or more locking pins 7 thereby significantly increases the transmittable torque from the first component 1 to the second component 2, without the second component 2 being rotated relative to the first component 1 when tightening the clamping nut. Furthermore, the at least one locking pin 7 can be used as an assembly aid, so that first component 1 and second component 2 are positioned exactly to one another.

Claims (14)

Fuel injection device (100) for injecting fuel into a combustion chamber of an internal combustion engine having a first component (1) and a second component (2, 2 ') which are screwed axially against one another by a clamping nut (5), wherein the clamping nut (5) in a threaded engagement with the first component (1), so that a first end face (1a) formed on the first component (1) is pressed together with a second end face (2a, 2a ') formed on the second component (2;
characterized in that
at least the first end face (1a) is structured in such a way that no twisting of the first component (1) and the second component (2; 2 ') occurs during tightening of the clamping nut (5), wherein the first end face (1a) has grooves (FIG. R). Fuel injection device (100) according to claim 1, characterized in that the structuring extends over the entire first end face (1a). Fuel injection device (100) according to claim 1, characterized in that the structuring extends over annular sector-shaped segments (1k) of the first end face (1a). Fuel injection device (100) according to claim 1, characterized in that the structuring extends over an annular segment (1r) of the first end face (1a). Fuel injection device (100) according to one of claims 1 to 4, characterized in that the first end face (1a) is structured by having an average roughness of 6 microns ≤ R _Z ≤ 16 microns. Fuel injection device (100) according to one of claims 1 to 5, characterized in that the grooves (R) extend in two different main directions, so that there is a cross-grinding. Fuel injection device (100) according to one of the preceding claims, characterized in that also the second end face (2a, 2a ') is structured. Fuel injection device (100) according to any one of the preceding claims, characterized in that at least one locking pin (7) as an additional anti-rotation between the first component (1) and the second component (2, 2 ') is arranged. Fuel injection device (100) according to one of the preceding claims, characterized in that the first component (1), the second component (2, 2 ') and the clamping nut (5) have a substantially axially symmetrical shape. Fuel injection device (100) according to any one of the preceding claims, characterized in that the clamping nut (5) on a shoulder (2s) of the second component (2) is applied and slides on tightening on this. Fuel injection device (100) according to one of claims 1 to 9, characterized in that a third component (3) on the second component (2 ') opposite the first component (1) is arranged and that on the third component (3) formed third end face (3a) is pressed together with a second component (2 ') formed on the other end face (2b'), wherein the clamping nut (5) on a shoulder (3s) of the third component (3) and abgleitet when tightening on this. Fuel injection device (100) according to claim 11, characterized in that also the third end face (3a) and / or the further end face (2b ') are structured. Fuel injection device (100) according to one of the preceding claims, characterized in that the structuring by sputtering, embossing, etching, sand blasting or laser structuring is applied. Fuel injection device (100) according to one of the preceding claims, characterized in that the fuel injection device (100) is a fuel injector.

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