Title of Invention

A SEALING DEVICE FOR A NOZZILE TENSION NUT OF A FUEL INDECTOR

Abstract

The invention relates to a sealing device for a fuel injector (1), particularly for a nozzle retaining nut (10) of the fuel injector (1), in order to create a fluid-tight seal relative to a seal seat edge (422), especially a cylinder head (40). Said sealing device comprises a sealing area (12) that is provided with a concave zone (122) having a radially circumferential concave outer contour (124) which can be made to sealingly rest against the seal seat edge (422). The invention further relates to methods for truing and creating a permanent, high pressure-tight fluid seal for a first part (10) of a fuel injector (1) relative to a sealing area of a second part (40), preferably a cylinder head (40).

Full Text

Description The invention relates to a sealing device for a fuel injector, in particular a sealing device for a nozzle retaining nut of the fuel injector, in order to ensure a fluid-tight connection between the fuel injector and a cylinder head. The invention also relates to a method for the fluid-tight sealing of a component of a fuel injector to a cylinder head. A nozzle retaining nut holds the two main components of a fuel injector - an injection nozzle and a valve body - tightly together. In the installed state of the fuel injector in the cylinder head, the injection nozzle projects into a combustion chamber of a motor vehicle engine, the valve body arranged above the injection nozzle actuating the injection nozzle. For this purpose it is necessary to seal the fuel injector against the cylinder head relative to the combustion chamber. This is effected by a suitable configuration of the nozzle retaining nut, which cooperates with a corresponding device, a seal seat, in the cylinder head. High demands are placed on such a sealing arrangement. Firstly, the sealing arrangement is exposed to high thermal stresses (-40°C when cold-starting in winter, to above +150°C under operating conditions) and, secondly, the sealing device is subjected to high mechanical stresses, in particular vibration stresses. In addition, the sealing arrangement must ensure a permanently sealed state between fuel injector and cylinder head which can withstand long-duration stresses. For this purpose, in the prior art, a horizontal edge, for example, is formed on the nozzle retaining nut, which seats on a likewise horizontal edge provided in the injector bore, and the nozzle retaining nut and the fuel injector are pressed against the cylinder head with a large static force. A permanently fluid-tight connection between the two edges is claimed is to be created by the provision of a large-area overlap. With such an arrangement both sealing faces must be very accurately machined in order to obtain any lastingly fluid-tight connection. Because of the lateral clearance between fuel injector and injector bore which must be provided, centering between fuel injector and injector bore is not possible with this configuration, so that the centering must be effected by means of other arrangements or devices. In DE 101 02 192 A1 a nozzle retaining nut has on a free end a tapered zone which is insertable in a corresponding tapered section of the injector bore. In the pre-assembled state, that is, when the fuel injector with nozzle retaining nut is inserted in the tapered injector bore, a circumferential angular difference from 2° to not more than 5° is present between the taper on the nozzle retaining nut and the tapered bore in the cylinder head. This ensures centering of the fuel injector in the injector bore, the fuel injector then being pressed into the bore with a large static force and a common sealing face being formed between the taper on the nozzle retaining nut and the conical bore in the cylinder head. Because the angular difference between the taper on the nozzle retaining nut and the tapered bore in the cylinder head is only 2° to 5°, a large overlap area between the two sealing faces exists in the pre-assembled state, so that, because of a jamming effect between the two sealing faces, self-centering is effected in only an unsatisfactory manner. This problem is countered in the prior art by surface-coating of the corresponding surfaces, in particular that of the nozzle retaining nut, in order to reduce the coefficient of sliding friction between nozzle retaining nut and injector bore. Despite the improvement of sliding friction between fuel injector and injector bore, the angular difference of 2° to 5° is too small to prevent jamming and to ensure self-centering. Through increasing the angular difference between the taper on the nozzle retaining nut and the tapered bore in the cylinder head to above 5°, an impairment of subsequent sealing quality would be incurred, which can lead to leakage during operation of the fuel injector. It is therefore an object of the invention to make available an improved fuel injector. In particular, the fuel injector should have good self-centering during installation of the fuel injector in the cylinder head and should establish in cooperation with the cylinder head a permanently fluid-tight connection between fuel injector and cylinder head. The object of the invention is achieved by means of a sealing device or sealing arrangement for a cylinder head and a fuel injector, in particular for a nozzle retaining nut of the fuel injector and the cylinder head, the one component having a radial, preferably completely circumferential, concave cross-sectional profile extending in a longitudinal direction, which profile can be placed against/impressed into a sealing face or sealing edge of a second component. In this arrangement the nozzle retaining nut of the fuel injector is preferably configured with a radial and completely circumferential concave chamfer. A seal seat edge, disposed horizontally or conically at an angle, is formed inside a stepped injector bore. The concave chamfer and the sealing rim of the seal seat edge cooperate in a particular manner. In a pre-assembled or centered state, the fuel injector is inserted with its nozzle retaining nut in the injector bore without any artificial forces acting on the fuel injector. The dimensions of the nozzle retaining nut and of the injector bore are selected such that the concave zone or concave chamfer of the nozzle retaining nut seats against the sealing rim of the seal seat edge. A kinematic reversal, that is, injector bore with concave chamfer and nozzle retaining nut with preferably tapered seal seat edge, is naturally also possible. The materials from which the components are manufactured may also be optionally exchanged for one another, or consideration must be given to their selection. The concave chamfer of the nozzle retaining nut is seated with only a circle or a thin annulus (centered state) against the rim of the seal seat edge, so that the nozzle retaining nut cannot jam in the injector bore. Because of a low friction between nozzle retaining nut and cylinder head, the fuel injector aligns itself in a self-centering manner in the injector bore. The concave chamfer preferably has a coefficient of adhesion and/or sliding friction as low as possible, whereby self-centering is further facilitated. The sealed state between fuel injector and cylinder head can then be adopted. In this state the fuel injector is pressed with a large static force into the injector bore or against the seal seat formed in the bore, whereby the concave zone, which is preferably harder relative to the cylinder head, preferably plastically deforms the seal seat edge and is pressed into the seal seat edge such that a fluid-tight connection between nozzle retaining nut and cylinder head is established. As a result of the deformation of the seal seat edge of the injector bore, a planar sealing section is formed between nozzle retaining nut and cylinder head, the seal seat edge being adapted to the concave chamfer as a result of the plastic deformation of the former, and permanent fluid-tightness with high surface pressure being established between fuel injector and cylinder head. Furthermore, it is thereby made possible to compensate unevenness and small depressions in the surfaces. Such arrangements are permanently resistant to pressure infiltration, so that a sealing arrangement highly resistant to thermal and mechanical stresses combined with permanent fluid-tightness is produced. In a preferred embodiment according to the invention, the angle, in the centered state, between a tangent at a point of contact between seal seat edge and concave chamfer, and the seal seat edge extending radially outwards, is approximately 10°, whereby good self-centering of the fuel injector in the cylinder head is achieved. During tightening of the fuel injector in the cylinder head, when deformation of the seal seat edge occurs, a tangent angle of a radially outermost point of contact between concave chamfer and seal seat edge changes to the value of 2° to 5° usual in the prior art. The cylinder head or seal seat edge are usually made of aluminum or magnesium. Through additional surface treatment of the concave chamfer, improved sliding properties of the nozzle retaining nut with respect to the sealing seat edge, or to its rim, are produced in this area, so that the fuel injector positions itself rapidly and with correct orientation with respect to the cylinder head in a simple manner. As a result of the provision of the concave chamfer, increased specific surface pressure is produced especially in the radial area of the seal seat edge located further inwards, whereby sealing between fuel injector and cylinder head is improved as compared to the prior art. The highest surface pressure occurs on the inner area of the seal seat edge, on which the internal pressure of the combustion chamber also impinges; this is especially advantageous because pressure infiltration can be effectively countered. Furthermore, as the concave chamfer is impressed into the seal seat edge of the injector bore, the tension gradient in the cylinder head is more favorable, as compared to the prior art, whereby fewer fissures are produced in the cylinder head, increasing the durability thereof. Conversely, the induction of force into the nozzle retaining nut is also optimized, as compared to the prior art, likewise resulting in a more favorable tension gradient within the nozzle retaining nut. In a preferred embodiment of the invention, a straight connecting line which, in the centered state, passes through the point of contact of the concave chamfer with the seal seat edge and through a circumferential point on the external diameter of the concave zone (the two points on the straight line and a longitudinal axis of the nozzle retaining nut lie in one plane) includes with a corresponding diametrically opposite straight line an angle of preferably approximately 108° or approximately 110°. In this case the radius of the preferably arcuate concave chamfer is 55mm±20mm, in particular 55mm±5mm. The invention also relates to a motor vehicle, an engine or a cylinder head with a fuel injector according to the invention, or a fuel injector with a nozzle retaining nut according to the invention. In addition, the object of the invention is achieved by means of a method for centering and fluidically sealing two components, in particular for centering and fluidically sealing a fuel injector or a nozzle retaining nut with respect to a cylinder head. In this method the first component has a radial and preferably completely circumferential concave zone which, for a pre-assembled state, is placed against a seal seat edge of the second component for centering the two components with respect to one another. When the two components are put into an assembled state, the concave zone moves into the second component, while the material of the seal seat edge is elastically, but preferably plastically, deformed, in such a way that a common sealing face between concave zone and seal seat edge is produced as a result of surface pressure, which common sealing face is fluid-tight even at high internal pressures. Further embodiments of the invention are apparent from the other dependent claims. The invention is explained below with reference to embodiments and to the appended drawings, in which: Fig. 1a shows an inventive sealing arrangement in the pre- assembled state; Fig. 1b shows the sealing arrangement from Fig. 1a in the assembled state; Fig. 2 shows a nozzle retaining nut with an inventive sealing device; Fig. 3a shows the inventive sealing device from Fig. 2 in a centered state with a cylinder head in partial section; Fig. 3b shows the inventive sealing device from Fig. 2 in the sealed state with the cylinder head; Fig. 4 shows the inventive sealing area of the nozzle retaining nut from Fig. 2 in an enlarged representation, and an additional detail in section; Fig. 5a shows a second embodiment of the inventive sealing device in the centered state in partial section, and Fig. 5b shows the second embodiment of the inventive sealing device from Fig. 5a in the sealed state. When positional references such as "top'/"above" or "bottom"/"below", and "right" or "left" are given in what follows, they relate to Fig. 2, in which a nozzle retaining nut 10 is shown in a sectional view on the right and in a non-sectional view on the left, the nozzle retaining nut 10 clamping an injection nozzle 20 arranged below to a valve body 30 arranged above. Figs. 1a and 1b show a sealing arrangement according to the invention, in particular for providing a permanent and high pressure-tight fluid seal between two components 10 and 40, for example a nozzle retaining nut 10 and a cylinder head 40. Fig. 1a represents a pre-assembled state of the two components 10, 40, the component 10 preferably being self-centered with respect to the component 40, for which reason this pre-assembled state is also called the centered state. However, self-centering of the two components 10, 40 with respect to one another is not essential to the invention; it is sufficient if the first component 10 can be placed against the second component 40, without reciprocal self-centering. However, if reciprocal centering is necessary, but self-centering is not possible, it should be effected with external means. For centering and sealing, the first component 10 has a concave zone 122 and the second component 40 a seal seat edge 422. In the pre-assembled state of the two components 10, 40, the central section of the concave zone 122 rests against the rim 424 of the seal seat edge 422. In Figs. 1a and 1b the central section of the concave zone 122 can be seen only as a point or small area (point of contact between concave zone 122 and seal seat edge 422); for the preferably rotationally symmetrical component 10, however, the central section is in idealized form a circle or a thin annulus. Seating of the smallest diameter of the concave zone 122 (lower edge of component 10) on the seal seat edge 422 (cf. Figs. 5a and b) is also possible (further embodiment). In a sealed state of the two components 10, 40, represented in Fig. 1b, a section of the concave zone 122 is imprinted or impressed, with an at least elastic, preferably plastic, deformation of the material of the second component 40, in the seal seat edge 422. The impressing of the first component 10 in the second component 40 takes place on a section of the rim 424 of the seal seat edge 422 disposed radially outwardly from a longitudinal axis L of the sealing arrangement. The deformation of the second component 40 is indicated by means of a broken line in Fig. 1b. By means of this upper portion bulging radially inwardly along the concave zone 122, the sealing area between the two components 10, 40 is additionally enlarged, increasing the fluid-tightness of the two components 10, 40. Figs. 2 to 4 show a first preferred embodiment of the sealing arrangement according to the invention, the inventive sealing arrangement being embodied on a nozzle retaining nut 10 and a cylinder head 40 associated therewith. The inventive sealing arrangement serves to seal a fuel injector 1, preferably via its nozzle retaining nut 10, in an injector bore 42 of the cylinder head 40 with respect to a combustion chamber of an internal combustion engine. The inventive sealing device is located preferably on the lower free end of the nozzle retaining nut 10 which clamps together an injection nozzle 20 and a valve body 30 and combines them to form a fuel injector 1 (see Fig. 2); however, the inventive sealing device may also be provided on the fuel injector 1 itself, in which case the nozzle retaining nut 10 performs no sealing functions, or only other sealing functions, for the fuel injector 1. This first embodiment of the sealing device on the nozzle retaining nut 10 comes into abutment with a seal seat in the injector bore 42 (Figs. 3a and 3b), sealing device and seal seat core cooperating together according to the principle of the invention as shown in Figs. 1a and 1b. In the embodiment according to the invention, a sealing and centering zone 12 of the nozzle retaining nut 10 is preferably formed in two sections. In this case a tapered zone 126 coming from below adjoins a concave zone 122 on the nozzle retaining nut 10. Concave zone 122 and tapered zone 126 are used for inserting the nozzle retaining nut 10 and the fuel injector 1 in the injector bore 42 (Figs. 3a and 3b), the concave zone 122 being designed to center the nozzle retaining nut 10 on a seal seat edge 422 of the injector bore 42 in the centered or pre-assembled state. The nozzle retaining nut 10 is preferably radially symmetrical, the concave zone 122 having a radially extending and completely circumferential concave chamfer 124, the cross-sectional profile of which extends upwardly in the longitudinal or axial direction L of the nozzle retaining nut 10. However, the nozzle retaining nut 10 may also be configured such that the tapered zone 126 is absent and only the concave zone 122 is present on the lower, substantially conical section of the nozzle retaining nut 10. A cylindrical portion 14 of the nozzle retaining nut 10, in which cylindrical portion 14 the valve body 30 is primarily received, adjoins the sealing area 12 of the nozzle retaining nut 10 at the top. In the centered state of the nozzle retaining nut 10 and of the fuel injector 1, represented in Fig. 3a, the concave chamfer 124 and the concave zone 122 rest on a rim 424 of a seal seat edge 422. The rim 424 of the seal seat edge 422 describes substantially a circle or a thin annulus on the concave chamfer 124. The more circular (imagined in a plane) this section on the concave chamfer 124 is, the more truly centered is the nozzle retaining nut 10 in the injector bore 42 of the cylinder head 40. The injector bore 42 is preferably a stepped circular-cylindrical bore the lower section of which, of smaller diameter, receives a section of the injection nozzle 20, and the upper section of which, of larger diameter, receives the nozzle retaining nut 10 of the fuel injector 1. Both zones are preferably connected via a cone or annular bevel (referred to hereinafter as the tapered zone 426); however, a horizontal step, which includes a right angle with the respective portion of the injector bore 42, is also possible. In the centered state, the point of contact M (sectional representation in Fig. 3a), or the circle/annulus of contact M (real situation with the fuel injector 1 centered in the injector bore 42), of rim 424 and concave chamfer 124 lies between a circumferential point/circumferential circle/annulus I having the (lower) internal diameter DI (Fig. 4) of the concave chamfer 124, and a circumferential point/circumferential circle/annulus A having the (upper) external diameter DA of the concave chamfer 124, the point of contact M preferably lying within the first third or within the first half of the distance from circumferential point I to circumferential point A. In what follows only the points M, I and A are referred to, and not the corresponding circles or annuli; however, the contact circles or contact annuli are also meant. Furthermore, in what follows geometrical references, for example angle values and references to positions of straight lines, relate to planes in which the longitudinal or axial axis L of the nozzle retaining nut 10 is contained; in particular, a plane to be considered coincides with the drawing plane of Fig. 4. The seal seat edge 422 of the injector bore 42 is preferably an inner section of the tapered zone 426 of the injector bore 42, the tapered zone 426 having with the tapered zone 126 of the nozzle retaining nut 10 a circumferential aperture angle of approximately 0.5° to 5° (ideal centered state -the circle formed by all points M is perpendicular to L). Further angular relationships, as represented in Fig. 3a, are specified in the context of the explanation of Fig. 4. Fig. 3b shows a sealed state of nozzle retaining nut 10 and cylinder head 40, the nozzle retaining nut 10 being impressed into the seal seat edge 422 of the injector bore 42 with preferably plastic deformation of the seal seat edge 422. In this case deformation of the inner seal seat edge 422 again preferably takes place towards the inside (cf. description of Fig. 1b). Ideally, an annular surface pressure with the greatest and most uniform possible annulus thickness and the highest possible surface pressure is generated, which has no points of uneven pressure. Preferably, the edge (A) of the external diameter of the concave chamfer 124 is not impressed, or only just is not impressed, in the tapered zone 426 or the seal seat edge 422. Fig. 4 shows in detail the sealing area 12 of the nozzle retaining nut 10, which is divided into tapered zone 126 and concave zone 122. The tapered zone 126 and the concave zone 122 have a common circle which can be seen, inter alia, at point A in Fig. 4. This is at the same time a circumferential point A of the largest external diameter DA of the concave zone 122. If the concave zone 122 is now followed downwards (and inwards towards L) from point A of the concave chamfer 124, one moves on the concave chamfer 124 via the point of contact M of concave chamfer 124 and rim 424 (in the centered state) to the circumferential point I on the smallest internal diameter DI of the concave zone 122. In a preferred embodiment of the invention, DA= 13 mm, the diameter DMof a circle formed from point M being approximately 10.9 mm in the centered state. In this case, as mentioned above, the point M is located on the first third or the first half of the distance from point I to point A. The concave chamfer 124 is preferably in the form of an arc of a circle, the radius R of which may vary between 20 mm and 100 mm. In a preferred embodiment of the invention the radius of the concave chamfer 124 is 55±5 mm. Correspondingly other radii are produced if the inventive concept is applied to other components; in principle, it is important that a concave contour is involved. Non-arcuate contours, which differ from a simple taper, are also possible according to the invention. In particular, constant transitions to the other regions of the nozzle retaining nut 10 at the edges of the concave chamfer at I and A are advantageous, as the tension gradient in the nozzle retaining nut 10, and the induction of force to the tapered zone 426 at the edges (I, A) of the cone chamfer 124, are more favorable and change less abruptly, for which purpose a clothoid, for example, is suitable. The following angular values for the inventive sealing device relate to an internal aperture angle of a cone which is formed by a straight line rotating around the longitudinal axis L of the nozzle retaining nut 10. Such a straight line TM is the tangent at the point M in the centered state of the nozzle retaining nut 10, the aperture angle αM of the cone in the centered state being preferably from 104° to 110°, depending on the radius R of the concave chamfer 124. A corresponding angle αA of the tangent TA at point A is preferably from 107° to 113°, again depending on the radius R of the concave chamfer 124. An angle ß of a straight line MA connecting points M and A is preferably from 106° to 112°. All these values are related to a point M which is established in the centered state of the nozzle retaining nut 10. As the nozzle retaining nut 10 is impressed into the cylinder head 40, the point M begins to travel along the concave chamfer 124 in the direction of the point A (and, of course, linearly along the seal seat edge 422) (point Mn), a straight line MnA constantly approaching the tangent TA. This is made clear in the sectional representation of the detail in Fig. 4. Here, Mn is a radially outermost point of contact between concave chamfer 124 and seal seat edge 422. Further embodiments according to the invention which derive from the above are specified in the table by the following parameters: (Table Removed) In the table the variables relate to Fig. 4, a value of Mn = 12.0 mm between M and A on the concave chamfer 124, upon moving from M to A, being entered as an example in the table. Fig. 5a shows a second embodiment of the inventive sealing device for the fuel injector 1 or the nozzle retaining nut 10, in which it is not the concave chamfer 124 which centers on the rim 424 of the seal seat edge 422, but the lower edge on the seal seat edge 422. This has the advantage that the injector bore 42 can be configured with a smaller diameter and can extend closer to the injection nozzle 20 of the fuel injector 1. Optionally, only the upper edge of the concave chamfer 124 may rest on the seal seat edge 422 (circle/annulus A, largest diameter of concave chamfer 124). Furthermore, it is also possible that in the centered state both circular edges I and A rest on the seal seat edge 422, which arrangement has the advantage that a centered position of the two components can be monitored in that the centered position is adopted only when both circular edges I and A rest completely against the seal seat edge 422. The sealed state is shown in Fig. 5b, the two circles or annulus edges I and A being impressed in the seal seat edge 422 of the cylinder head 40 and forming two sealing zones, in the case illustrated. The more firmly the nozzle retaining nut 10 is impressed in the cylinder head 40, the smaller the gap remaining between nozzle retaining nut 10 and cylinder head 40 becomes. Other configurations of the sealed state are also possible, in which, for example, only the lower circular edge I or only the upper circular edge A is impressed in the seal seat edge 422. No cavity preferably exists between nozzle retaining nut 10 and cylinder head 40. In implementing such a sealing arrangement it may be necessary to provide venting of the cavity initially present. This venting preferably occludes itself automatically through the impressing of the nozzle retaining nut 10 into the cylinder head 40. This may be effected, for example, by a groove in the cylinder head 40 or in the nozzle retaining nut 10, into which groove material of the nozzle retaining nut 10 or material of the cylinder head 40 penetrates during the impressing. Bores which are occludable in like manner are also suitable. The preceding embodiments, which relate to the nozzle retaining nut 10, should also apply to the fuel injector 1 which is not sealed with respect to the cylinder head 40 by means of its nozzle retaining nut 10 but which has the inventive device on another section. The inventive device on the fuel injector 1 and a corresponding seal seat on or in the cylinder head then together form the sealing arrangement according to the invention. We Claim: 1. A sealing device for a nozzle tension nut (10) of a fuel injector (1) and for a cylinder head, for fluid-tight sealing with respect to a sealing-seat margin (422), with a sealing region (12) on the nozzle tension nut (10) or the cylinder head (40), characterized in that the sealing region (12) has a concave region (122) with a radial peripheral concave outer contour (124) which can be brought to bear sealingly against the sealing-seat margin (422) of the cylinder head (40) or of the nozzle tension nut (10). 2. A sealing device as claimed in claim 1, wherein the concave region (122) being configured with a fully peripheral concave chamfer (124), and a radially running frustoconical region (126) adjoining the concave region (122). 3. A sealing device as claimed in Claim 1, wherein in a centring state the concave region (122) being placed onto the sealing-seat margin (422), and a peripheral circular portion of the concave chamfer (124) being seated on an edge (424) of the sealing-seat margin (422). 4. A sealing device as claimed in Claim 1, wherein in a sealing state the concave region (122) being connected fixedly to the sealing-seat margin (422), the concave region (122) being pressed into the sealing-seat margin (422) as a result of an at least elastic, preferably plastic deformation of the sealing-seat margin (422). 5. A sealing device as claimed in any of the preceding claims, wherein the concave chamfer (124) being formed radially and peripherally on a sealing face of the nozzle tension nut (10) which is seated so as to bear on a sealing-seat margin (422) of an injector bore (42) of the cylinder head (40). 6. A sealing device as claimed in any of the preceding claims, wherein in the centring state the angle between the sealing-seat margin (422) and a tangent to a contact point (M) of the concave chamfer (124) and edge (424) amounting to 14 ± 2°, preferably 10 ± 1°, particularly preferably 7 ± 1°. 7. A sealing device as claimed in any of the preceding claims, wherein at least one portion, extending in the longitudinal direction (L) of the fuel injector (1), of the concave region (122) cooperating, in the sealing state, with the sealing-seat margin (422) of the injector bore (42) in such a way that the fuel injector (1) is secured, fluid-tight, with respect to the cylinder head (40). 8. A sealing device as claimed in any of the preceding claims, wherein in the sealing state the angle between the tangent (TM) to a radially outermost contact point (M) between the concave chamfer (124) and sealing-seat margin (422) amounting to 7 ± 1°, preferably 4 ± 1°, particularly preferably 2 ± 0.5°. 9. A sealing device as claimed in any of the preceding claims, wherein the sealing-seat margin (422) being designed as a frustoconical cone margin, the aperture angle of which is larger than an angle which the frustoconical region (126) of the sealing region forms, the aperture angle between the two amounting to 0.5° to 5°, in particular to 1° to 4°, preferably 2 ±0.5°. 10. A sealing device as claimed in any of the preceding claims, wherein in the centring state a contact point (M) of the concave chamfer (124) and edge (424) and an outside diameter point (A) of the concave chamfer (124) forming a connecting straight line (MA) which assumes with the longitudinal axis (L) of the fuel injector (1) an angle of 50° to 60°, in particular of 52° to 58°, preferably of 53° to 56°, and particularly preferably of 54° to 55°. 11. A sealing device as claimed in any of the preceding claims, wherein a profile of the concave chamfer (122) being part-circular and having a radius (R) of 30 mm to 90 mm, in particular of 45 mm to 65 mm, preferably of 50 mm to 60 mm, and particularly preferably of 55 ± 2.5 mm. 12. A sealing device as claimed in any of the preceding claims, wherein the face of the concave chamfer (122) being polished, preferably by means of a shot-peening method. 13. A sealing device as claimed in any of the preceding claims, wherein the material of the sealing-seat margin (422), is preferably aluminium, being softer than the material of the concave region (122) which is preferably produced from steel. 14. A sealing device as claimed in any of the preceding claims, wherein the inner contour which lies opposite the concave chamfer (122) of the nozzle tension nut (10) being of convex design.

Documents:

5907-DELNP-2007-Abstract-(27-06-2012).pdf

5907-delnp-2007-abstract.pdf

5907-DELNP-2007-Assignment-(27-06-2012).pdf

5907-delnp-2007-Claims-(20-06-2013).pdf

5907-DELNP-2007-Claims-(27-06-2012).pdf

5907-delnp-2007-claims.pdf

5907-delnp-2007-Correspondence Others-(20-06-2013).pdf

5907-DELNP-2007-Correspondence Others-(27-06-2012).pdf

5907-DELNP-2007-Correspondence-Others-(01-05-2009).pdf

5907-DELNP-2007-Correspondence-Others-(13-09-2010).pdf

5907-DELNP-2007-Correspondence-Others-(16-08-2010).pdf

5907-delnp-2007-correspondence-others-1.pdf

5907-delnp-2007-correspondence-others.pdf

5907-delnp-2007-Description (Complete)-(20-06-2013).pdf

5907-DELNP-2007-Description (Complete)-(27-06-2012).pdf

5907-delnp-2007-description (complete).pdf

5907-delnp-2007-Drawings-(20-06-2013).pdf

5907-delnp-2007-drawings.pdf

5907-DELNP-2007-Form-1-(13-09-2010).pdf

5907-DELNP-2007-Form-1-(16-08-2010).pdf

5907-DELNP-2007-Form-1-(27-06-2012).pdf

5907-delnp-2007-form-1.pdf

5907-delnp-2007-form-18.pdf

5907-DELNP-2007-Form-2-(27-06-2012).pdf

5907-delnp-2007-form-2.pdf

5907-DELNP-2007-Form-26-(01-05-2009).pdf

5907-delnp-2007-form-26.pdf

5907-DELNP-2007-Form-3-(27-06-2012).pdf

5907-delnp-2007-form-3.pdf

5907-delnp-2007-Form-5-(20-06-2013).pdf

5907-delnp-2007-form-5.pdf

5907-delnp-2007-form-6-(01-05-2009).pdf

5907-DELNP-2007-GPA-(13-09-2010).pdf

5907-DELNP-2007-GPA-(16-08-2010).pdf

5907-DELNP-2007-GPA-(27-06-2012).pdf

5907-DELNP-2007-Others-Document-(01-05-2009).pdf

5907-delnp-2007-pct-237.pdf

5907-delnp-2007-pct-304.pdf

5907-DELNP-2007-Petition-137-(27-06-2012).pdf

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