WO2023166139A1

WO2023166139A1 - Fuel injection valve for internal combustion engines

Info

Publication number: WO2023166139A1
Application number: PCT/EP2023/055362
Authority: WO
Inventors: Marco Ganser
Original assignee: Ganser-Hydromag Ag
Priority date: 2022-03-03
Filing date: 2023-03-02
Publication date: 2023-09-07

Abstract

The invention relates to a fuel injection valve (10.1), comprising a nozzle chamber (165) and a first and a second injection valve seat (163, 164), and at least one first and at least one second injection opening (161, 162) emanating from the nozzle chamber (165), a movably arranged injection valve member (56), which has a main needle (57), a needle sleeve (58), and a needle pin (59) arranged at least partially in the needle sleeve (58), the needle sleeve (58) having a first valve sealing face (581) for sealingly cooperating with the first injection valve seat (163) for connecting and separating the at least one first injection opening (161) to and from a high-pressure chamber (26), and the needle pin (59) having a second valve sealing face (591) for sealingly cooperating with the second injection valve seat (164) for connecting and separating the at least one second injection opening (162) to and from the high-pressure chamber (26).

Description

FUEL INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES

field of invention

The present invention relates to a fuel injection valve for intermittently injecting fuel into the combustion chamber of a

internal combustion engine .

Background of the Invention

Fuel injection valves are used to inject fuel directly into the combustion chamber of an internal combustion engine, in particular for diesel engines. In addition to conventional diesel engines, so-called dual-fuel systems have been proposed in recent years as efficient and low-emission alternatives for ships, power-generating engines and, in some cases, commercial vehicles. A challenge in the dual-fuel systems is the required separate injection of fuel, such as diesel or marine diesel oil, as a pilot jet when operating with gas as the main fuel. In particular, different injection parameters are required for the pilot jet injection of fuel from conventional fuel injection, such as injection quantity, injection pressure, injection configuration etc. desired.

The provision of different injection parameters is also desirable for other purposes such as pilot injections or pre-injections in addition to the main injection, what requires an extension of conventional injection systems.

A dual-fuel injection system is described, for example, in US2007/0246561 A1 with a fuel injection system that is designed to generate two different spray patterns via adjacent needle valve elements that are controlled independently of one another. The fuel injection system includes a fuel injection injector having an injector body defining a hollow interior configured to receive pressurized fuel, a first nozzle configured in spray configuration to provide a first fuel spray pattern, and a second nozzle configured in spray configuration to do so is to provide a second fuel spray pattern that differs from the first fuel spray pattern. The first and second nozzles are adapted to inject fuel supplied from a common source into a combustion chamber. The fuel injection injector further includes a first needle valve element positioned in the hollow interior of the injector body, the first needle valve element corresponding to the first nozzle, and a second needle valve element positioned in the hollow interior of the injector body and corresponding to the second nozzle. The second needle valve element is spaced from the first needle valve element and is disposed adjacent to the first needle valve element. The first and second nozzles are configured to inject fuel supplied from a common source into a combustion chamber. Presentation of the invention

Against the background of the expanded requirements when operating with different injection parameters for different injection purposes or operating modes, e.g. in dual-fuel systems, it is typically desirable to provide reliable controllability of the injection processes.

It is therefore an object of the present invention to provide a fuel injector which at least partially improves the prior art.

This object is achieved with a fuel injection valve having the features of the independent claim. Advantageous configurations of the invention are given in the dependent claims and in the present description and the figures.

The invention relates to a fuel injector for intermittently injecting fuel into the combustion chamber of an internal combustion engine, comprising a housing that defines a longitudinal axis and has a high-pressure fuel inlet and a nozzle body with a nozzle space and a first and a second injector seat. The nozzle body has at least one first injection opening, starting from the nozzle chamber, and at least one second injection opening, starting from the nozzle chamber, for injecting fuel into the combustion chamber of the internal combustion engine. A high-pressure chamber is arranged in the housing High-pressure fuel inlet runs to the nozzle chamber. An injection valve member is also arranged in the housing so that it can be adjusted in the direction of the longitudinal axis. The fuel injection valve also includes a compression spring, which acts on the injection valve member with a closing force directed towards the first injection valve seat. The compression spring is preferably supported on the one hand on the injection valve member and on the other hand is supported in a stationary manner relative to the housing.

The fuel injection valve also includes a hydraulic control device for controlling the movement of the injection valve member along the longitudinal axis, the injection valve member having a main needle with a control piston, which is arranged on an end of the main needle facing away from the first injection valve seat and is guided in a sliding fit in a guide part, a needle sleeve, which is arranged at an end of the main needle facing the first injection valve seat, and has a needle pin arranged at least partially in the needle sleeve.

The needle sleeve has a first valve sealing surface which is configured to cooperate sealingly with the first injection valve seat for connecting and disconnecting the at least one first injection opening to and from the high-pressure chamber. The needle pin has a second valve sealing surface configured to sealingly cooperate with the second injector seat for connecting and disconnecting the at least one second injection port to and from the high pressure chamber. By providing the needle sleeve for connecting the at least one first injection opening to the high-pressure space and for separating the at least one first injection opening from the high-pressure space and the needle pin for connecting the at least one second injection opening to the high-pressure space and for separating the at least one second injection opening from the high-pressure space a targeted injection of fuel through the at least one first injection opening and/or the at least one second injection opening can be provided.

The sealing interaction of the needle sleeve with the first injection valve seat enables a reliable connection and disconnection of the at least one first injection opening with and from the high-pressure chamber, and the sealing interaction of the needle pin with the second injection valve seat enables a reliable connection and disconnection of the at least one second injection opening with and from the high pressure room. In particular, the at least one first injection opening can be separated from the high-pressure chamber by sealing contact of the needle sleeve via the first valve sealing surface on the first injection valve seat. Correspondingly, the at least one second injection opening can be separated from the high-pressure chamber by the needle pin sealingly resting against the second injection valve seat via the second valve sealing surface. By lifting the needle sleeve or the needle pin from the first or second injection valve seat, the at least one first injection opening or the at least one second injection opening can be connected to the high-pressure chamber. The Working together can therefore be both a concern and a

include lifting.

The needle pin and the needle sleeve can be adjusted relative to one another along the longitudinal axis. In particular, the needle sleeve can be stationary in relation to the main needle and the needle pin can be adjusted in relation to the main needle, or alternatively the needle pin can be stationary in relation to the main needle and the needle sleeve can be arranged in an adjustable manner in relation to the main needle. Since the needle pin and the needle sleeve are adjustable relative to one another, the at least one first injection opening and the at least one second injection opening can be selectively closed or opened by adjusting the main needle or the needle sleeve and/or the needle pin.

The fuel injector offers the advantage that different operating phases (such as pre-injection and main injection), which are set by selectively connecting and/or separating the at least one first and/or the at least one second injection opening, through the respective interaction of the needle sleeve or the needle pin with the first and the second injection valve seat can be achieved. The needle sleeve also offers the advantage that the main pressure drop across the first injection valve seat can be used, for example to achieve improved pre-injection with the desired atomization.

The control and adjustment of the injection valve member or the main needle can be achieved in a precise and reliable manner by the hydraulic control device. The The fuel injector therefore makes it possible to provide two different injection processes with different injection parameters, such as injection quantity, injection pressure, injection duration, injection pattern, etc., suitable for optimum engine combustion in each case, with the same injection valve member using the at least one first injection opening and the at least one second injection opening.

The fuel injection valve preferably has a large number, e.g. two, three, four, five, six or more, of first injection openings arranged radially symmetrically, preferably at a first level, and a large number, e.g. two, three, four, five, six or more of radially symmetrically arranged second injection openings, preferably at a second height.

In one configuration, the at least one first injection opening and the at least one second injection opening have different minimum diameters.

By choosing different minimum diameters for the at least one first injection opening and the at least one second injection opening, different injection cross sections can be provided for different injection purposes. For example, a smaller minimum diameter can be selected for pilot injection or pilot injection. On the other hand, a larger minimum diameter can be selected, for example, for use as a main injector for e.g. diesel, marine diesel or heavy fuel oil.

In the case of a multiplicity of first injection openings, the first injection openings preferably have the same ones Minimum diameter and particularly preferably have the same geometries. However, configurations are also conceivable in which the plurality of first injection openings have different geometries and/or minimum diameters from one another. Correspondingly, in the case of a large number of second injection openings, their minimum diameters are preferably the same and their geometries are particularly preferably the same. However, configurations with different geometries and/or minimum diameters are also conceivable given the large number of second injection openings.

In one configuration, the at least one second injection opening is arranged downstream of the at least one first injection opening.

Due to the mutual adjustability of the needle pin and the needle sleeve along the longitudinal axis, this spatial configuration of the at least one first injection opening and the at least one second injection opening can be used to improve the selective connection and disconnection of the at least one first injection opening and the at least one second injection opening to and from the be reached in the high-pressure chamber.

In one embodiment, the needle sleeve is attached to the main needle and the needle pin is guided in the needle sleeve in an adjustable manner along the longitudinal axis and relative to the main needle.

In one configuration, the at least one first injection opening has a smaller minimum diameter than the minimum diameter of the at least one second injection opening. The at least one first injection opening can thus be used, for example, for diesel pilot injection in order to ignite a lean (natural) gas/air mixture or, for example, for pre-injection in diesel or heavy oil operation.

The starting point from which the at least one first injection opening extends from the nozzle space is preferably further radially spaced from the longitudinal axis of the housing than the starting point from which the at least one second injection opening extends from the nozzle space.

In one configuration, the injection valve member is designed to separate the at least one first injection opening with the needle sleeve and the at least one second injection opening with the needle pin from the high-pressure chamber in a closed position, and in an intermediate position to separate the at least one first injection opening by lifting the needle sleeve from the first injection valve seat with the to connect the high-pressure chamber and to separate the at least one second injection opening with the needle pin from the high-pressure chamber, and in an open position the at least one first injection opening by lifting the needle sleeve from the first injection valve seat and the at least one second injection opening by lifting the needle pin from the second injection valve seat with the high-pressure chamber connect.

At least three (connection/disconnection) configurations can therefore be provided with the fuel injection valve and the injection valve member, which can be used for different operating modes or operating phases. For example, the Intermediate position can be used in this embodiment for pilot injection in gas operation or for pilot injection in diesel or heavy oil operation, since the at least one first injection opening has a smaller minimum diameter than the at least one second injection opening. Configurations with an intermediate position in which the roles of the at least one first injection opening and the at least one second injection opening are reversed are described, inter alia, below. The open position can be used, for example, in diesel or heavy oil operation to open both the at least one first and the at least one second injection opening and to use the fuel injection valve as the main injector for diesel or heavy oil as the main fuel.

In this configuration, the fuel injection valve can therefore provide a pilot jet injection in gas operation via the at least one first injection opening, which has a smaller minimum diameter than the at least one second injection opening.

The fuel injection valve offers the advantage that the fuel injection valve can also be used for diesel or heavy oil operation. In this configuration, the at least one first injection opening, which has a smaller minimum diameter than the at least one second injection opening, can then be used for a pre-injection or pilot injection and by opening the at least one first and the at least one second

Injection opening the main injection are provided. In diesel or heavy oil operation, in one variant for a pre-injection, the at least one first injection opening, which has a smaller minimum diameter than the at least one second injection opening, can be opened and closed again after the pre-injection. After a specific time interval, the at least one first injection opening and the at least one second injection opening can then be opened for the main injection.

In a further variant, a stepped injection can be carried out in diesel or heavy oil operation. For example, the at least one first injection opening, which has a smaller minimum diameter than the at least one second injection opening, can be opened for a pilot injection and the at least one second injection opening can also be opened for a main injection.

The fuel injector therefore offers the advantage that different types of use can be achieved with the same fuel injector, in particular on the one hand as a pilot injector and on the other hand as a main injector with variably adjustable pre-injection.

The needle pin with the second valve sealing surface preferably protrudes from the end of the needle sleeve facing the first injection valve seat.

In one embodiment, a stroke of the needle sleeve is provided from the closed position to the intermediate position when the needle pin is in a stationary position, the stroke preferably being between 0.1 and 0.2 mm. The timing of the stepped injection, in particular the duration of the pre-injection, can be adjusted by varying the stroke of the needle sleeve along the longitudinal axis with the needle pin in a stationary position, in which the at least one second injection opening is separated from the high-pressure chamber. A short pre-injection can be achieved, for example, by a small stroke of the needle sleeve with the needle pin in a stationary position, in which the at least one second injection opening is separated from the high-pressure chamber.

In one embodiment, the needle sleeve has a sleeve shoulder and the needle pin has a needle shoulder, the sleeve shoulder and the needle shoulder being able to engage in one another between the intermediate position and the open position such that the needle pin can be lifted from the second injection valve seat through the needle sleeve.

The needle pin can therefore be adjusted by controlling the main needle or the needle sleeve firmly connected to the main needle by the hydraulic control device. With the sleeve shoulder and the needle shoulder, the travel of the needle sleeve that can be covered when the needle pin is in a stationary position, in which the at least one second injection opening is separated from the high-pressure chamber, can also be defined by the axial distance between the sleeve shoulder and the needle shoulder in the closed position.

In one embodiment, the needle pin has a guide section downstream of the needle shoulder and a collar section upstream of the needle shoulder, with greater radial play between the collar section and the needle sleeve exists as between the guide portion and the needle hub.

The needle pin is preferably guided via a sliding fit of the guide section in the needle sleeve. With the greater radial play between the collar section and the needle sleeve, double guidance can be avoided. The collar section is preferably formed adjacent to the guide section upstream of the guide section, so that the needle shoulder is formed at the transition between the guide section and the collar section. The collar section preferably has a larger radial diameter than the guide section. Correspondingly, the needle sleeve preferably has a lower guide passage for guiding the guide section and an upper guide passage for receiving the collar section, the upper guide passage having a larger radial diameter than the lower guide passage. The upper guide passage is preferably adjacent to the lower guide passage, so that the sleeve shoulder is formed at the transition between the lower and the upper guide passage.

In one embodiment, a needle control chamber is arranged between the needle pin and the main needle and is connected to the high-pressure chamber and delimited axially by the needle pin and the main needle.

The needle pin can be adjusted along the longitudinal axis with respect to the main needle by means of the needle control space axially delimited by the needle pin and the main needle. Since the needle control chamber is connected to the high-pressure chamber, furthermore, on the end of the needle pin facing away from the second injection valve seat, the pressure of the high-pressure chamber acts on the needle pin in order to close the at least one second injection opening or separate it from the high-pressure chamber.

In one embodiment, the main needle has a recess at the end facing the first injector seat, with a radial side wall of the recess at least partially delimiting the needle control chamber radially and preferably a transverse bore in the radial side wall of the recess connecting the needle control chamber with the high-pressure chamber.

Due to the radial side wall, which at least partially radially delimits the needle control chamber, the main needle can therefore have a sleeve-shaped end at its end facing the first injection valve seat, which end is defined by the recess. Preferably, the needle hub is secured onto the hub-shaped end of the main needle, e.g., by an interference fit.

In one embodiment, the needle control chamber is at least partially delimited radially by the needle sleeve and is preferably connected to the high-pressure chamber via a transverse bore in the needle sleeve.

The needle control chamber can be delimited in an upper area by the radial side wall of the recess of the main needle and in a lower area by the needle sleeve.

In one embodiment, a retaining spring is arranged in the needle control chamber, which the needle pin with a direction against applied to the second injection valve seat directed holding force.

The retaining spring offers the advantage that the needle pin can be held in a defined position relative to the main needle, particularly in the open position. Preferably, the retaining spring abuts the main needle at its upstream end and the needle pin at its downstream end. The retaining spring is preferably prestressed with a prestressing force and is additionally compressed during the transition from the open position to the closed position, so that the retaining spring can act on the needle pin with a retaining force directed against the second injection valve seat.

In one embodiment, in the open position, the retaining spring presses the needle shoulder of the needle pin against the sleeve shoulder of the needle sleeve.

In the open position, the retaining spring can therefore reach the defined position of the needle pin by pressing the needle shoulder against the sleeve shoulder.

In one embodiment, the needle sleeve is attached to the end of the main needle facing the first injection valve seat, which is sleeve-shaped or nub-shaped, preferably via a press fit.

In one embodiment, the needle sleeve is fastened by laser welding, via a thread or by hard soldering to the end of the main needle which faces the first injection valve seat and which is sleeve-shaped or nub-shaped. In configurations of the main needle with a nub-shaped end facing the first injection valve seat, the nub-shaped end can have an upper nub and a lower nub adjoining the upper nub with a smaller radial diameter. The lower nub may serve to radially retain the retaining spring at its upstream end.

In one embodiment, the needle sleeve is integral with the

Main needle trained.

In one embodiment, the needle pin is attached to the main needle and the needle sleeve is guided adjustably on the needle pin along the longitudinal axis and relative to the main needle.

In one configuration, the at least one second injection opening has a smaller minimum diameter than the minimum diameter of the at least one first injection opening.

The at least one second injection opening can thus be used, for example, for diesel pilot injection in order to ignite a lean (natural) gas/air mixture or, for example, for pre-injection in diesel or heavy oil operation.

In one configuration, the injection valve member is designed to separate the at least one first injection opening with the needle sleeve and the at least one second injection opening with the needle pin from the high-pressure chamber in a closed position, and in an intermediate position to close the at least one second injection opening by lifting the needle pin from the second injection valve seat with the To connect the high-pressure chamber and the at least one first to separate the injection opening with the needle sleeve from the high-pressure chamber, in an open position to connect the at least one first injection opening by lifting the needle sleeve from the first injection valve seat and the at least one second injection opening by lifting the needle pin from the second injection valve seat to the high-pressure chamber.

At least three (connection/disconnection) configurations can therefore be provided with the fuel injection valve and the injection valve member, which can be used for different operating modes or operating phases. For example, the intermediate position in this embodiment can be used for a pilot injection in gas operation or for a pilot injection in diesel or heavy oil operation, since the at least one second injection opening has a smaller minimum diameter than the at least one first injection opening. The open position can be used, for example, in diesel or heavy oil operation to open both the at least one first and the at least one second injection opening and to use the fuel injection valve as the main injector for diesel or heavy oil as the main fuel.

In this configuration, the fuel injection valve can therefore provide pilot injection in gas operation via the at least one second injection opening, which has a smaller minimum diameter than the at least one first injection opening.

The fuel injection valve offers the advantage that the fuel injection valve can also be used for a diesel or diesel engine. Heavy fuel oil operation can be used. In this configuration, a pre-injection or pilot injection can be provided via the at least one second injection opening, which has a smaller minimum diameter than the at least one first injection opening, and the main injection can be provided via the opening of the at least one first and the at least one second injection opening.

In diesel or heavy oil operation, in one variant for a pre-injection, the at least one second injection opening, which has a smaller minimum diameter than the at least one first injection opening, can be opened and closed again after the pre-injection. After a specific time interval, the at least one first injection opening and the at least one second injection opening can then be opened for the main injection.

In a further variant, a stepped injection can be carried out in diesel or heavy oil operation. For example, the at least one second injection opening, which has a smaller minimum diameter than the at least one first injection opening, can be opened for a pilot injection and the at least one first injection opening can also be opened for a main injection.

In one embodiment, a stroke of the needle pin is provided from the closed position to the intermediate position when the needle sleeve is in a stationary position, the stroke preferably being between 0.1 and 0.2 mm. The timing of the stepped injection, in particular the duration of the pre-injection, can be adjusted by varying the stroke of the needle pin along the longitudinal axis with the needle sleeve in a stationary position, in which the at least one first injection opening is separated from the high-pressure chamber. A short pre-injection can be achieved, for example, by a small stroke of the needle pin when the needle sleeve is in a stationary position, in which the at least one first injection opening is separated from the high-pressure chamber.

In one embodiment, the needle sleeve has a sleeve shoulder and the needle pin has a needle shoulder, the sleeve shoulder and the needle shoulder being able to engage in one another between the intermediate position and the open position such that the needle sleeve can be lifted from the first injection valve seat by the needle pin.

The needle sleeve can therefore be adjusted by controlling the main needle or the needle pin firmly connected to the main needle by the hydraulic control device. With the sleeve shoulder and the needle shoulder, the stroke that can be covered by the needle pin when the needle sleeve is in a stationary position, in which the at least one first injection opening is separated from the high-pressure chamber, can also be defined by the axial distance between the sleeve shoulder and the needle shoulder in the closed position.

In one embodiment, the needle pin has a guide section downstream of the needle shoulder and a collar section upstream of the needle shoulder, with greater radial play between the collar section and the needle sleeve consists than between the guide section and the needle sleeve and the collar section has a smaller radial diameter than the guide section.

The needle sleeve is preferably guided via a sliding fit of the guide section on the needle pin. With the greater radial play between the collar section and the needle sleeve, double guidance can be avoided. The collar section is preferably formed adjacent to the guide section upstream of the guide section, so that the needle shoulder is formed at the transition between the guide section and the collar section. Accordingly, the needle hub preferably has a lower guide passage whereby it is guided on the needle pin by the guide portion, and an upper guide passage for receiving the collar portion, the upper guide passage having a smaller radial diameter than the lower guide passage. The upper guide passage is preferably adjacent to the lower guide passage, so that the sleeve shoulder is formed at the transition between the lower and the upper guide passage. The upper guide passage is preferably formed by an axial bore of the needle sleeve, through which the collar portion of the needle pin protrudes. The needle hub may be cup-shaped, with the upper guide passage being located in the bottom of the cup-shaped hub so that the collar portion of the needle pin protrudes through the bottom of the cup-shaped hub.

In one embodiment, a retaining spring is arranged in the axial direction between the main needle and the needle sleeve, which acts on the needle sleeve with a holding force directed towards the first injection valve seat.

The retaining spring allows the needle sleeve to be held in a defined position relative to the main needle, particularly in the open position. Preferably, the retaining spring abuts the main needle at its upstream end and the needle hub at its downstream end. The retaining spring is preferably prestressed with a prestressing force and is additionally compressed during the transition from the open position to the closed position, so that the retaining spring can act on the needle sleeve with a retaining force directed against the first injection valve seat.

In one embodiment, the retaining spring is held radially at its upstream end by a sleeve-shaped end of the main needle facing the first injection valve seat, which has a reduced radial diameter compared to the region of the main needle adjoining the sleeve-shaped end upstream.

In one embodiment, the retaining spring is held radially at its upstream end by a sleeve-shaped end of the needle pin that faces away from the second valve sealing surface.

In one embodiment, the retaining spring is held radially at its downstream end by a holding region of the needle sleeve which is remote from the first injection valve seat and has a reduced diameter. In one embodiment, in the open position, the retaining spring presses the sleeve shoulder of the needle sleeve against the needle shoulder of the needle pin.

In the open position, the retaining spring can therefore reach the defined position of the needle sleeve by pressing the sleeve shoulder against the needle shoulder.

In one embodiment, the needle pin is attached to the end of the main needle facing the first injection valve seat, which end is sleeve-shaped or nub-shaped, preferably via a press fit.

With a sleeve-shaped end of the main needle facing the first injection valve seat, the needle pin can have a fastening shank on its end facing away from the second valve sealing surface, which can be accommodated in the sleeve-shaped end of the main needle to fasten the needle pin to the main needle.

In the case of a nub-shaped end of the main needle facing the first injection valve seat, the needle pin can have a fastening sleeve on its end facing away from the second valve sealing surface, in which the nub-shaped end of the main needle can be accommodated for fastening the needle pin to the main needle.

In one embodiment, the needle pin is fastened by laser welding, via a thread or by hard soldering to the end of the main needle which faces the first injection valve seat and which is designed in the form of a sleeve or nubs. In one embodiment, in the intermediate position and/or the closed position between the needle pin and the needle sleeve, an intermediate space is formed in a region adjoining the second injection valve seat, which is connected to the high-pressure chamber, preferably via a transverse bore in the needle sleeve.

As a result, in the intermediate position, fuel that is under high-pressure chamber pressure can be injected from the intermediate space through the at least one second injection opening into the combustion chamber of the internal combustion engine.

In one embodiment, the needle pin has a profile that tapers toward the second valve sealing surface, with the tapering profile preferably having at least one step.

As a result of the gradation, a region of the intermediate space arranged between the needle sleeve and the needle pin can be formed, which is connected to the high-pressure space, for example, via the transverse bore in the needle sleeve.

The at least one first injection opening is preferably arranged at a greater radial distance from the longitudinal axis than the at least one second injection opening.

In one embodiment, the first injection valve seat is conical with a first opening angle and the second injection valve seat is conical with a second opening angle and is arranged downstream of the first injection valve seat, the first opening angle being greater than the second opening angle. In one embodiment, the first injector seat is conical with a first opening angle and the second injector seat is conical with a second opening angle and is arranged downstream of the first injector seat, the first and second opening angles being the same.

In one embodiment, the first injector seat is conical with a first opening angle and the second injector seat is conical with a second opening angle and is arranged downstream of the first injector seat, the first opening angle being smaller than the second opening angle.

In one configuration, the at least one second injection opening is arranged downstream of the second injection valve seat. The at least one second injection opening can therefore emanate from a part of the nozzle chamber which is arranged below or downstream of the second injection valve seat. In certain configurations, however, the at least one second injection opening can also originate from the second injection valve seat.

In one embodiment, the needle sleeve has an outer radially circumferential recess on a radially outer side surface adjacent to the first valve sealing surface.

Due to the outer, radially circumferential recess, the needle sleeve can be provided locally with a reduced wall thickness in a section adjacent to the first valve sealing surface. The outer, radially circumferential recess is preferably at an axial distance from the first Valve sealing surface arranged so that the wall thickness of the needle sleeve is reduced locally. With the locally reduced wall thickness, elasticity of the needle sleeve in the area of the first valve sealing surface can be provided, so that the needle sleeve or the first valve sealing surface can absorb and compensate for angular differences between the first injection valve seat and the first valve sealing surface, which can impair the sealing interaction.

In one embodiment, an outer, radially encircling collar is formed between the outer, radially encircling recess and the first valve sealing surface.

With the outer, radially circumferential collar, a kind of resilient part can be provided, through which the elasticity of the needle sleeve can be achieved in the area of the first valve sealing surface.

In one embodiment, the outer radially circumferential recess forms an outer cone-shaped closing surface of the radially outer side surface, which is arranged facing away from the first valve sealing surface.

In particular, the outer radially circumferential collar can be at least partially delimited by the outer conical closing surface on a side facing away from the first injection valve seat and at least partially by the first valve sealing surface on a side facing the first injection valve seat. The outer cone-shaped closing surface preferably has an inclination opposite to that of the first valve sealing surface. Furthermore, the pressing of the needle sleeve against the first injection valve seat in the closed position can be improved by the outer conical closing surface, since the high-pressure chamber pressure can act on the outer conical closing surface.

In one embodiment, the needle sleeve has an inner radially circumferential recess on a radially inner side surface adjacent to the first valve sealing surface.

The inner, radially circumferential recess can provide a distance between the needle pin and the needle sleeve in an end region of the needle sleeve facing the first injection valve seat, which is significantly larger than the clearance of the sliding fit of the needle pin. As a result, during the transition from the closed position to the intermediate position, an undesired lifting of the needle pin when the needle sleeve is raised in configurations with a needle sleeve attached to the main needle or an undesired lifting of the needle sleeve when the needle pin is raised in configurations with a needle pin attached to the main needle due to a radial inwardly directed force from the high-pressure chamber and a resulting clamping effect of the needle sleeve on the needle pin can be reduced or avoided. The reduction or avoidance of the clamping effect can also be achieved by a tapering profile of the needle pin or by a radially circumferential recess in the needle pin.

Furthermore, the needle sleeve can be locally reduced in a section adjacent to the first valve sealing surface due to the inner radially circumferential recess Wall thickness are equipped. The inner, radially circumferential recess is preferably arranged at an axial and/or radial distance from the first valve sealing surface. The wall thickness of the needle sleeve can therefore be reduced locally. With the locally reduced wall thickness, elasticity of the needle sleeve in the area of the first valve sealing surface can be provided, so that the needle sleeve or the first valve sealing surface can absorb and compensate for angular differences between the first injection valve seat and the first valve sealing surface, which can impair the sealing interaction.

In one embodiment, an inner, radially encircling collar is formed between the inner, radially encircling recess and the first valve sealing surface.

With the inner, radially circumferential collar, a type of resilient part can be provided, through which the elasticity of the needle sleeve can be achieved in the area of the first valve sealing surface.

In one embodiment, the inner, radially circumferential recess forms an inner, conical closing surface of the radially inner side surface, which is arranged facing away from the first valve sealing surface.

In particular, the inner radially circumferential collar can be at least partially delimited by the inner conical closing surface on a side facing away from the first injection valve seat and at least partially by the first valve sealing surface on a side facing the first injection valve seat. The inner conical End surface preferably has one of the first

Valve sealing surface corresponding inclination.

The inner conical end surface can also improve the pressing of the needle sleeve against the first injection valve seat in the closed position, since the high-pressure chamber pressure can act on the inner cone-shaped end surface.

In one embodiment, the first valve sealing surface has an inner valve sealing surface and an outer valve sealing surface, and the needle sleeve has a radially circumferential, trough-shaped groove at one end facing the first injection valve seat, with the inner and outer valve sealing surfaces adjoining the trough-shaped groove.

The radially circumferential, trough-shaped groove offers the advantage that in the closed position, the sealing separation of the at least one first injection opening from the high-pressure chamber can be improved by providing a volume with a pressure between the first injection valve seat and the trough-shaped groove, which is advantageously lower than is the high pressure chamber pressure. Furthermore, two ring sealing surfaces can be provided by the inner and the outer valve sealing surface, as a result of which the effective first valve sealing surface can be reduced and adhesion forces can be reduced.

In one embodiment, the at least one first injection opening is arranged in such a way that when the first valve sealing surface interacts in a sealing manner with the first injection valve seat to separate the at least one first Injection opening of the high-pressure chamber, the trough-shaped groove is in communication with the at least one first injection opening.

Because the trough-shaped groove is in communication with the at least one first injection opening during the sealing interaction of the first valve sealing surface with the first injection valve seat for separating the at least one first injection opening from the high-pressure chamber, i.e. in the closed position, it can advantageously be achieved that in the between the first injection valve seat and the trough-shaped groove volume of the combustion chamber pressure prevails, which is lower than the high-pressure chamber pressure.

The trough-shaped groove can therefore increase the area in which the combustion chamber pressure prevails in the closed position at the first injection valve seat, whereby the sealing separation of the at least one first injection opening from the high-pressure chamber can be improved.

In one embodiment, the at least one first injection opening extends from the nozzle space via a radially circumferential, trough-shaped nozzle body groove.

With the trough-shaped nozzle body groove, in the closed position, similar to the trough-shaped groove of the needle sleeve, a volume can be provided in the first injection valve seat, in which a defined pressure prevails with the combustion chamber pressure. In particular, the area in which the combustion chamber pressure prevails can be enlarged, thereby sealingly separating the at least one first injection port of the high pressure chamber can be improved.

In one embodiment, the transitions between the at least one first injection opening and the side wall of the nozzle space are rounded. Alternatively or in addition, the transitions between the at least one second injection opening and the side wall of the nozzle space can be rounded. In particular, the transitions between the at least one first injection opening and the trough-shaped nozzle body groove are preferably rounded. Due to the trough-shaped nozzle body groove, the transitions between the at least one first injection opening and the side wall of the nozzle space can be rounded off more easily. Rounding off the transition between an injection opening and the side wall of the nozzle chamber or a trough-shaped nozzle body groove offers the advantage of a more stable flow of fuel through the injection opening over time.

In one embodiment, the at least one first injection opening has a first opening section starting from the nozzle chamber and a second opening section adjoining the first opening section, the diameter of the second opening section being larger than the diameter of the first opening section.

Alternatively or in addition, the at least one second injection opening can have a first opening section starting from the nozzle chamber and a second opening section adjoining the first opening section, the diameter of the second opening section being larger than the diameter of the first opening section. The second opening section preferably opens into the combustion chamber of the internal combustion engine. The widening shape of the at least one first and/or second injection opening enables improved atomization of fuel for the injection to be achieved, since the at least one first and/or second injection opening has a narrow diameter over a reduced length, namely along the first opening section and has a flared profile thanks to the second opening portion. Because of this profile, the most advantageous ratio of hole diameter and hole length of the first opening section of the at least one first and/or second injection opening can be realized in order to achieve optimal atomization of the fuel in the combustion chamber. The second opening portion may at least partially have a cylindrical or conical profile. With a conical profile of the second opening section, the maximum and/or average diameter of the second opening section is preferably larger than the diameter of the first opening section.

In one configuration, a cover with a central recess for the at least one first and the at least one second injection opening is attached to a lower end of the nozzle body in such a way that a radially circumferential intermediate space is formed between the cover and the nozzle body, with the nozzle body having two bores , which are designed to supply and discharge cooling liquid into the intermediate space.

In one embodiment, the fuel injector further includes an intermediate part, which together with the Guide part and the control piston limits a control chamber; wherein the hydraulic control device is designed to control the movement of the injection valve member along the longitudinal axis by changing the pressure in the control chamber; wherein the hydraulic control device comprises an intermediate valve with a mushroom-shaped intermediate valve member, which has a shaft guided in a guide recess of the intermediate part and a head, and with an intermediate valve seat formed on a side of the intermediate part facing the head and interacting with the head, the intermediate valve member in an open position of the intermediate valve member releases a first connection between a high-pressure fuel inlet connected to the high-pressure chamber and the control chamber and in a closed position of the intermediate valve member interrupts the first connection between the high-pressure fuel inlet and the control chamber and separates the control chamber from a valve chamber - except for a throttle passage; an electrically actuable actuator assembly for connecting the valve space to and isolating the valve space from a low pressure fuel return; wherein the intermediate valve member releases a second connection between the high-pressure fuel inlet and the valve chamber in the open position of the intermediate valve member and interrupts the second connection between the high-pressure fuel inlet and the valve chamber in the closed position of the intermediate valve member.

The guide part and the intermediate part can be designed as independent components. However, it is also possible for the guide part and the intermediate part to be formed integrally as a one-piece component. The throttle passage is preferably formed on the intermediate valve member, particularly preferably on the head of the intermediate valve member. However, the throttle passage can also be formed on the intermediate part. In further variants, the throttle passage can be formed between the intermediate valve member and another component, such as by a gap between the intermediate valve member and the intermediate part or the guide part. The throttle passage formed on the intermediate valve member can, on the side facing away from the control chamber, open into a blind hole, which is recessed on the intermediate valve member and belongs to the valve chamber. Preferably, the throttle passage is formed in the intermediate valve member adjacent to the control space. The throttle passage and the blind hole are preferably formed centrally to the longitudinal axis. As a result, on the one hand the throttle passage can be formed with the desired length and on the other hand the blind hole can form part of the valve chamber.

List of Characters

Embodiments of the invention are explained in more detail using the following figures and the associated description. They show schematically:

1 shows a longitudinal section through a fuel injection valve from the prior art;

2 shows a section of an embodiment of a

Fuel injection valve in a longitudinal section; 3a shows a detail of a further embodiment of a fuel injector in a longitudinal section;

FIG. 3b enlarged compared to FIG. 3a, the area of the embodiment of the fuel injection valve encircled there by a circle denoted by A; FIG.

4a shows a detail of a further embodiment of a fuel injector in a longitudinal section;

FIG. 4b enlarged compared to FIG. 4a, the area of the embodiment of the fuel injection valve encircled there by a circle denoted by B; FIG.

5a shows a detail of a further embodiment of a fuel injection valve in a longitudinal section;

FIG. 5b enlarged compared to FIG. 5a, the area of the embodiment of the fuel injection valve encircled there by a circle denoted by C; FIG.

6 shows a detail of a further embodiment of a fuel injection valve in a longitudinal section;

7a shows a detail of a further embodiment of a fuel injection valve in a longitudinal section; FIG. 7b shows an enlarged downstream area of the embodiment of the fuel injection valve compared to FIG. 7a.

Description of exemplary embodiments

In the description of the figures, the same reference numbers are used for parts of the embodiments that correspond to one another.

FIG. 1 shows an illustration of a fuel injection valve 10′ from the prior art, for example according to WO2016/041739 A1 for intermittent injection of fuel into a combustion chamber of an internal combustion engine. Fuel injector 10' has a housing 12', which defines a longitudinal axis L, with a housing body 14', a nozzle body 16', on which an injection valve seat 18' is formed, and an actuator receiving body 20', which is located between housing body 14' and nozzle body 16 ' is arranged. A union nut 22' supported on the nozzle body 16' receives the actuator receiving body 20' and is threaded onto the housing body 14'. The housing body 14′ and the actuator receiving body 20′, as well as this and the nozzle body 16′, rest against one another at the ends, are pressed against one another in a sealing manner by means of the union nut 22′ and are aligned with one another in the direction of the longitudinal axis L. The outer shape of the housing 12' is at least approximately circular-cylindrical. On the end face of the housing body 14' facing away from the nozzle body 16', a high-pressure fuel inlet 24' is arranged, from which inlet 24' inside the housing 12' - through the housing body 14', the actuator receiving body 20' and the nozzle body 16' - to the injection valve seat 18' a high-pressure chamber 26' runs. The high-pressure fuel inlet 24' is formed by a valve carrier 28', which carries a check valve 30' and a basket-like perforated filter 32' for retaining any foreign particles in the fuel. The disk-shaped valve member of the check valve 30', which interacts with a valve seat formed on the valve carrier 28', has a bypass bore.

The check valve 30' allows fuel supplied via a high-pressure feed line to flow into the high-pressure chamber 26' in a known manner, practically without obstacles, but prevents fuel from flowing out of the high-pressure chamber 26' into the high-pressure feed line, with the exception of the bypass.

The construction and functioning of the assembly designed as a cartridge with the valve carrier 28', the check valve 30' and the hole filter 32' are disclosed in document WO2014/131497 A1. The high-pressure fuel inlet 24' and the valve carrier 28' with the check valve 30' and hole filter 32' can also be designed as disclosed in document WO2013/117311 A1. A possible embodiment of the high-pressure fuel inlet 24' and the check valve 30', as well as a rod filter instead of the hole filter 32' is known from document WO2009/033304 A1. The corresponding disclosure of the above Documents are incorporated by reference into the present disclosure.

Adjacent to the valve carrier 28', the high-pressure chamber 26' has a discrete spout chamber 34' formed on the housing body 14', which on the other hand is connected to the injection valve seat 18' via a flow channel 36' of the high-pressure chamber 26'.

The dimensioning and functioning of the discrete storage chamber 34' together with the check valve 30' with bypass is disclosed in document WO2007/009279 A1; the corresponding disclosure is deemed to be incorporated into the present disclosure by reference.

Instead of the non-return valve 30', a stationary immovable throttle can also be provided in certain embodiments.

An electrically actuated actuator arrangement 38' is accommodated in a recess of the actuator receiving body 20', which with its spring-loaded plunger 40' which is spring-loaded in one direction and movable in the other direction by means of an electromagnet of the actuator arrangement 38' is intended to close a low-pressure outlet in order Separate the valve space from a low pressure fuel return (see Figure 2) and release the low pressure outlet to connect the valve space and the low pressure fuel return. The longitudinal axis, designated 48', of the plunger 40' and thus of the actuator arrangement 38' runs parallel and eccentrically to the longitudinal axis L. Parallel to the discrete storage chamber 34', which is arranged eccentrically with respect to the longitudinal axis L of the housing 12' and thus of the fuel injector 10', runs from an electrical connection 31' through the housing body 14' to the actuator arrangement 38', a duct 33', in which the electrical control line for controlling the Actuator assembly 38 'is added.

The plunger 40′ reaches through the base of the cup-shaped actuator receiving body 20′, which forms a guide element for the plunger 40′. The plunger 40 ′ has guide wings projecting in the radial direction, with which it is slidably guided parallel to the longitudinal direction L on the guide element. The guide vanes form passages running in the longitudinal direction L, through which the fuel is transported from the low-pressure outlet to the low-pressure

Fuel return can flow.

In the flow direction of the fuel downstream of the injection valve seat 18', injection openings are formed in a known manner in a hemispherical free end region of the nozzle body 16', through which, when the injection valve member 56' is lifted from the injection valve seat 18', the fuel, which is under very high pressure, flows into the Combustion chamber of the internal combustion engine is injected.

The injection valve member 56' is needle-shaped and interacts with the injection valve seat 18'. The injection valve member 56' is movably guided in the direction of the longitudinal axis L in a guide borehole in the nozzle body 16' which is concentric with the longitudinal axis L and belongs to the high-pressure chamber 26', with radially outwardly open recesses on the injection valve member 56 'the low-loss flow of fuel to the injection valve seat 18' and to the injection openings is made possible.

FIG. 2 shows a detail of an embodiment of a fuel injector 10.1 in a longitudinal section, the detail corresponding to the area of the rectangle labeled II in FIG. The specific configuration of this area differs from fuel injector 10' shown in FIG. 1 and is described below with reference to FIG. For example, the actuator arrangement 38 is arranged mirrored about the longitudinal axis L in comparison to the actuator arrangement 38′ of FIG. The flow channel 36 is also arranged on the opposite side of the longitudinal axis L in comparison to the flow channel 36' of FIG. The remaining area outside of the area shown in FIG. 2 essentially corresponds to fuel injector 10' shown in FIG. 1 (ie outside of area II). This also applies accordingly to the details of the other embodiments of fuel injectors, which are shown in Figures 3-6.

As in FIG. 1, an electrically actuated actuator assembly 38 is accommodated in a recess of the actuator receiving body 20, which is intended to close a low-pressure outlet 42 with its plunger 40, which is spring-loaded in one direction and movable in the other direction by means of an electromagnet of the actuator assembly 38. to separate a valve space 44 from a low pressure fuel return 46 and the low pressure outlet 42 release to connect the valve chamber 44 and the low-pressure fuel return 46 with each other. The longitudinal axis of the ram 40, designated 48, and thus of the actuator arrangement 38, runs parallel and eccentrically to the longitudinal axis L. The guide vanes form passages running in the longitudinal direction L, through which the fuel can flow from the low-pressure outlet 42 to the low-pressure fuel return 46 .

In FIG. 2, the union nut 22 can also be seen, which presses the nozzle body 16, the actuator receiving body 20 and the housing body (not visible in FIG. 2) against one another in a sealing manner.

An injection valve member 56 is arranged in the housing 12 so that it can be adjusted in the direction of the longitudinal axis L and has a shoulder 55 on which a compression spring 63 is supported at one end. With its other end, the compression spring 63 is supported at the front on a guide sleeve 64 forming a guide part. The compression spring 63 holds the guide part 64 with its end face facing away from the compression spring 63 in sealing contact with an intermediate part 66.

In the guide part 64 , a control piston 68 arranged at an upstream end of the injection valve member 56 is guided displaceably along the longitudinal axis L with a close sliding fit of approximately 3 μm to 5 μm. The control piston 68, the guide part 64 and the intermediate part 66 limit one Control chamber 70 compared to the high-pressure chamber 26 from. The intermediate part 66 is part of a hydraulic control device 72 which is designed to control the movement of the injection valve member 56 along the longitudinal axis L. The hydraulic control device 72 can be designed, for example, as described in WO2021/165275 A1 or WO2020/260285 A1, the corresponding disclosures of which are considered incorporated into the present disclosure by reference.

A circular-cylindrical guide recess runs through the intermediate part 66 from the flat end side facing the control chamber 70 to the likewise flat end side facing away from the control chamber 70 . A shaft 76 of a mushroom-shaped intermediate valve member 78 is guided in this. A head 80 of the intermediate valve member 78 integrally formed with the stem 76 is located in the control chamber 70 and interacts with its side facing the intermediate part 66 with the intermediate part 66, the flat end face of which forms an annular intermediate valve seat. A throttle passage 90 is formed on the head 80 and runs from the end face of the head 80 facing the control piston 68 to a blind hole in the intermediate valve member 78 .

The intermediate valve member 78 forms, together with the intermediate valve seat formed on the intermediate part 66, an intermediate valve 83 of the hydraulic control device 72. For the formation of the intermediate valve 83, reference is made to WO2021/165275 A1 or WO2020/260285 A1, the corresponding disclosures of which are incorporated by reference into the present Revelation included apply. The nozzle body 16 has a nozzle chamber 165 connected to the high-pressure chamber 26 and a first injection valve seat 163 and a second injection valve seat 164 . The nozzle body 16 also has a large number of first injection openings 161 emanating from the nozzle chamber 165 and a large number of second injection openings 162 emanating from the nozzle chamber 165 and arranged downstream of the first injection openings 161 for injecting fuel into the combustion chamber of the internal combustion engine. The first injection openings 161 have a smaller minimum diameter than the minimum diameters of the second injection openings 162 and can be used for pilot injection or when operating with gas as the main fuel for a

pilot injection can be used.

The compression spring 63 acts on the injection valve member 56 with a closing force acting in the direction of the first injection valve seat 163 . Injection valve member 56 comprises a main needle 57, with control piston 68 being arranged on an end of main needle 57 facing away from first injection valve seat 163, a needle sleeve 58, which is arranged on an end of main needle 57 facing first injection valve seat 163, and a partially in the Needle sleeve 58 arranged needle pin 59. The needle pin 59 is guided in the needle sleeve 58 along the longitudinal axis L and relative to the main needle 57 so that it can be adjusted.

The needle sleeve 58 has a first valve sealing surface 581 which is designed to cooperate in a sealing manner with the first injection valve seat 163 for connecting and separating the first injection openings 161 to and from the high-pressure chamber 26 . The needle pin 59 has a second Valve sealing surface 591, which is designed to cooperate sealingly with the second injection valve seat 164 for connecting and separating the first injection openings 161 with and from the high-pressure chamber 26.

A needle control chamber 51 is arranged between the needle pin 59 and the main needle 58 and is axially delimited by the needle pin 59 and the main needle 57 . The needle control chamber 51 is formed in an upstream region by a recess in the main needle 57 at its end facing the first injection valve seat 163 . A radial side wall 572 of the recess radially delimits the needle control chamber 51 , a transverse bore 571 in the radial side wall 572 of the main needle 57 connecting the needle control chamber 51 to the high-pressure chamber 26 . The radial side wall 572 has a sleeve-shaped end to which the needle sleeve 58 is attached via an interference fit. A retaining spring 52 is arranged in the needle control chamber 51 and acts on the needle pin 59 with a retaining force directed towards the second injection valve seat 164 . The needle pin 59 has a guide portion 592 which is guided in a lower guide passage of the needle sleeve 58 with a sliding fit. Upstream at the guide section

Adjacent to 592, the needle pin 59 has a collar portion

593, which is accommodated in an upper guide passage of the needle sleeve 58. There is more play between collar section 593 and needle sleeve 58 than between guide section 592 and needle sleeve 58.

The injection valve member 56 is designed to pass through the first injection openings 161 with the needle sleeve 58 in a closed position, which is shown in FIG sealing interaction of the first valve sealing surface 581 with the first injection valve seat 163 and the second injection openings 162 with the needle pin 59 by sealing interaction of the second valve sealing surface 591 with the second injection valve seat 164 from the high-pressure chamber 26. By raising the needle sleeve 58 from the first injection valve seat 163, the intermediate position can be reached in which the first injection openings 161 are released and connected to the high-pressure chamber 26, while the needle pin 59 remains in the position in which the needle pin 59 rests on the second injection valve seat 164 presses and the second injection openings 162 are thereby separated from the high-pressure chamber 26. By further lifting the needle sleeve 58, the needle pin 59 is also raised due to an interlocking of a sleeve shoulder of the needle sleeve 58 and a needle shoulder of the needle pin 59 (see, for example, Fig. 3a), so that the open position is reached, in which the first injection openings 161 and the second Injection openings 162 are released and connected to the high-pressure chamber 26. The raising and lowering of the needle sleeve 58 and the needle pin 59 is achieved by moving the main needle 57 and the injection valve member 56 along the longitudinal axis L, the movement of the injection valve member 56 being controlled by the hydraulic control device 72 with the intermediate valve 83 in a precise and reliable manner become. Accordingly, by adjusting the injection valve member 56 along the longitudinal axis L, either the first injection openings 161 for a pilot or pilot injection or the first and the second injection openings 161, 162 for a main injection of liquid fuel can be opened from the high-pressure chamber 26 into the combustion chamber of the internal combustion engine.

FIG. 3a shows a section of a further specific embodiment of a fuel injector 10.2 in a longitudinal section, only the lower region of fuel injector 10.2 being shown. The remaining, upper area can be configured in accordance with the embodiment shown in FIG. In the embodiment shown in FIG. 3a, the needle sleeve 58 has an outer radially circumferential recess 584 on a radially outer side surface adjacent to the first valve sealing surface 581 . The outer, radially encircling recess 584 forms an outer cone-shaped closing surface 585 of the radially outer side surface, which is arranged facing away from the first valve sealing surface 163 . On a radially inner side surface adjacent to the first valve sealing surface 581 , the needle sleeve 58 also has an inner radially circumferential recess 583 . Due to the recesses 583, 584, the wall thickness of the needle sleeve 58 is reduced locally.

It can also be seen in FIG. 3a that the first injection openings 161 each have a first opening section 161.1 starting from the nozzle chamber 165 and a second opening section 161.2 adjoining the first opening section 161.1. The second opening section 161.2 has a conical profile, so that the first injection openings 161 each widen towards the combustion chamber of the internal combustion engine. The diameter of the second opening section 161.2 is greater than the diameter of the first in terms of both its maximum and its mean diameter Opening section 161.1. The second injection openings 162 emanate from a part 166 of the nozzle space 165 which is arranged below or downstream of the second injection valve seat 164 . It is therefore sufficient for the needle pin 59 in the closed position and in the intermediate position to simply seal the second injection valve seat 164 with the second valve sealing surface 591 or with a line seal or a radially circumferential sealing surface with a small width in order to separate the second injection openings 162 from the high-pressure chamber 26 to separate. The first injection openings 161, on the other hand, emanate from the first injection valve seat 163, so that the needle sleeve 58 seals the first injection openings 161 in the closed position with the first valve sealing surface 581 radially inside and radially outside, i.e. twice or with a surface seal, also radially inside and outside .

The needle pin 59 is guided with a guide section 592 in a lower guide passage 582.1 of the needle sleeve 58 with a sliding fit. A collar section 593 with a larger radial diameter than the guide section 592 is arranged upstream adjacent to the guide section 592 . The collar section is accommodated in an upper guide passage 582.2, there being greater play between the collar section 593 and the upper guide passage 582.2 than between the guide section 592 and the lower guide passage 582.1.

A needle shoulder 594 is formed at the transition between the guide section 592 and the collar section 593 . The needle sleeve 58 has a sleeve shoulder 586 which at the transition between the lower guide passage 582.1 and the upper guide passage 582.2 is formed. When the needle sleeve 58 is raised between the intermediate position and the open position of the injection valve member 56, the needle shoulder 594 and the sleeve shoulder 586 can be engaged in one another in such a way that the needle pin 59 can be pushed away from the second injection valve seat 164 with the aid of the needle sleeve 58 in order to uncover the second injection openings 162. In the open position of the injection valve member 56, the retaining spring 52 arranged in the needle control chamber 51 presses the needle shoulder 594 of the needle pin 59 against the sleeve shoulder 586 of the needle sleeve 58 and thus holds the needle pin 59 in a defined position. During the transition from the open position to the closed position of the injection valve member 56, the retaining spring 52 is compressed so that the retaining spring 52 can act on the needle pin 59 with a retaining force directed against the second injection valve seat 164 when the open position of the injection valve member 56 is reached again.

The second valve sealing surface 591 of the needle pin 59 protrudes from the end of the needle sleeve 58 facing the first injection valve seat 163 . When the injection valve member 56 is moved from the open position to the closed position, the needle pin 59 with the second valve sealing surface 591 therefore first separates the second injection openings 162 from the high-pressure chamber 26 before the needle sleeve 58 with the first valve sealing surface 581 separates the first injection openings 161 from the high-pressure chamber 26.

First injection valve seat 163 is conical with a first opening angle and second injection valve seat 164 is conical with a second opening angle. the second injector seat 164 adjoins the first injector seat 163 downstream. In the embodiment shown in Figure 3a, the first opening angle of the first injection valve seat 163 is greater than the second opening angle of the second injection valve seat 164.

FIG. 3b shows the area of the embodiment of fuel injector 10.2 encircled in FIG. 3a by a circle labeled A. An outer, radially encircling collar 587 is formed between the outer, radially encircling recess 584 and the first valve sealing surface 581 . The outer radially circumferential collar 587 is delimited on a side facing away from the first valve sealing surface 581 by the outer conical closing surface 585 formed from the outer radially circumferential recess 584 , which has an incline opposite to the first injection valve seat 163 . Because of the recess 584 and the collar 587 , elasticity of the needle sleeve 58 is provided in the area of the first valve sealing surface 581 .

The first valve sealing surface 581 has an inner valve sealing surface 581.1 and an outer valve sealing surface 581.2, which can provide a first and a second annular sealing surface. The elasticity of the needle sleeve 58 due to the recess 584 and the collar 587 therefore acts in particular in the area of the outer valve sealing surface 581.2. At the end facing the first injection valve seat 163, the needle sleeve 58 has a radially circumferential, trough-shaped groove 5810, which is adjoined by the inner valve sealing surface 581.1 and the outer valve sealing surface 581.2. In the closed position of the intermediate valve member shown in FIG. 3b When the first valve sealing surface 581 interacts in a sealing manner with the first injection valve seat 163, the trough-shaped groove 5810 is in communication with the first injection openings 161 in order to separate the first injection openings 161 from the high-pressure chamber. The first injection openings 161 are therefore arranged at the same height along a radially circumferential line.

The inner radially circumferential recess 583 provides a sufficient distance between the needle pin 59 and the needle sleeve 58 in the area of the inner radially circumferential recess 583, so that during the transition from the closed position to the intermediate position, the needle pin 59 is not lifted up when the needle sleeve 58 is raised can be reduced or avoided due to a radially inward force from the high-pressure chamber and a resulting clamping effect of the needle sleeve 58 on the needle pin 59 .

FIG. 4a shows a detail of a further embodiment of a fuel injector 10.3 in a longitudinal section. As in fuel injector 10.2 shown in FIGS. 3a and 3b, needle sleeve 58 of fuel injector 10.3 has an outer, radially circumferential recess 584 on a radially outer side surface adjacent to first valve sealing surface 581. Needle sleeve 58 also has an inner, radially circumferential recess 583, which, however, is more pronounced than the inner, radially circumferential recess of fuel injector 10.2 in FIGS. 3a-b and is further described in FIG. 4b. In FIG. 4a also shows a holding nub 595 of the needle pin 59, which is used to hold the holding spring 52.

As already described for fuel injector 10.2 in FIGS. 3a-b, needle pin 59 has a needle shoulder 594 at the transition between collar section 593 and the guide section, which is designed to interact with sleeve shoulder 586. In the closed position of the intermediate valve member, the needle shoulder 594 and the sleeve shoulder 586 are arranged at an axial distance H from one another, which extends the stroke of the needle sleeve 58 for the movement from the closed position to the intermediate position when the needle pin 59 is in a stationary position, in which the at least one second injection opening from the High-pressure chamber is separated, defined. The distance or stroke H is between 0.1 to 0.2 mm.

FIG. 4b shows the area of the embodiment of fuel injector 10.3 encircled in FIG. 4a by a circle labeled B. An inner, radially encircling collar 589 is formed between the inner, radially encircling recess 583 and the first valve sealing surface 581 . The inner, radially circumferential recess 583 forms an inner, conical closing surface 588 which is arranged facing away from the first valve sealing surface 581 . The inner radially circumferential collar 589 is delimited on a side facing away from the first valve sealing surface 581 by the inner conical end surface 588 formed by the inner radially circumferential recess 583 . The inclination of the inner conical closing surface 588 corresponds to the inclination of the first valve sealing surface 581, ie it has the same sign. An outer, radially encircling collar 587 is formed between the outer, radially encircling recess 584 and the first valve sealing surface 581 . The outer radially circumferential collar 587 is delimited on a side facing away from the first valve sealing surface 581 by the outer conical closing surface 585 formed by the outer radially circumferential recess 584 , which has an incline opposite to the first injection valve seat 163 .

The first valve sealing surface 581 has an inner valve sealing surface 581.1 and an outer valve sealing surface 581.2, which can provide a first and a second annular sealing surface. Due to the inner radially encircling recess 583 and the inner radially encircling collar 589, in addition to the elasticity of the needle sleeve 58 in the area of the outer valve sealing surface 581.2, due to the outer radially encircling recess 584 and the outer radially encircling collar 587, there is an elasticity of the needle sleeve 58 in the area of the inner Valve sealing surface 581.1 provided.

In addition, as with fuel injection valve 10.2 in Figures 3a-b, the inner, radially circumferential recess 583 between the needle pin 59 and the needle sleeve 58 in the area of the inner, radially circumferential recess 583 provides a sufficient distance so that during the transition from the closed position to the intermediate position an undesired lifting of the needle pin 59 when the needle sleeve 58 is raised due to a radially inwardly directed force from the high-pressure chamber and a resulting clamping effect of the needle sleeve 58 on the needle pin 59 is reduced or avoided. At the end facing the first injection valve seat 163, the needle sleeve 58 has a radially circumferential, trough-shaped groove 5810, which is adjoined by the inner valve sealing surface 581.1 and the outer valve sealing surface 581.2 and which is connected to the first injection openings 161 when the intermediate valve member is in the closed position.

FIG. 5a shows a detail of a further embodiment of a fuel injector 10.4 in a longitudinal section. In comparison to fuel injectors 10.1-10.3 shown in FIGS. 2-4b, injector member 56 has a main needle 57 with a knob-shaped end facing first injector seat 163. The nub-shaped end of the main needle 57 has an upper nub 573 and a lower nub 574 adjoining the upper nub 573 downstream and having a smaller radial diameter. The needle sleeve 58 is fixed to the upper knob 573 of the main needle 57 by a press fit. The lower nub 574 serves to hold the retaining spring 52 at its upstream end. At its downstream end, the retaining spring is retained radially by a retaining nub 595 of the needle pin 59 .

The control chamber 51 is limited axially by the main needle 57 and the needle pin 59 . The control chamber 51 is delimited radially by the needle sleeve 58, in whose side wall a transverse bore 5811 is arranged, which connects the control chamber 51 to the high-pressure chamber 26 or to the nozzle chamber 165. The needle pin 59 again has a guide section 592, which is guided in a lower guide passage of the needle sleeve 58 with a sliding fit, and a collar section 593, which is received in an upper guide passage of the needle sleeve 58 on.

FIG. 5b shows the area of the embodiment of fuel injector 10.4 encircled in FIG. 5a by a circle labeled C. FIG. First injection valve seat 163 is cone-shaped with an opening angle which is the same size as the opening angle of cone-shaped second injection valve seat 164 , second injection valve seat 164 adjoining first injection valve seat 163 downstream. In comparison to fuel injectors 10.1-10.3 shown in FIGS. 2-4b, the first opening angle of first injector seat 163 and the second opening angle of second injector seat 164 are therefore the same. Furthermore, the needle sleeve 58 has no recesses in its area adjacent to the first valve sealing surface 581 . The first injection openings 161 extend from the nozzle chamber 165 via a radially circumferential, trough-shaped nozzle body groove 167 . Due to the nozzle body groove 167, two annular sealing surfaces are formed in the closed position of the injection valve member between the first injection valve seat 163 and the first valve sealing surface 581, which are arranged on the one hand radially inward and on the other hand radially outward in relation to the first injection openings 161. As in the fuel injectors 10.1-10.3 shown in FIGS. 2-4b, the first injection openings 161 have a first opening section 161.1 and a second

Opening section 161.2 with an expanding profile. The second injection ports 162 are below the second injector seat 164 arranged. In the

In the closed position of the injection valve member, an annular sealing line or annular sealing surface forms between the second valve sealing surface 591 and the second injection valve seat 164 . Inner and outer recesses of the needle sleeve corresponding to the recesses 583 and/or 584 shown in FIGS. 4a and 4b are also possible in the embodiment according to FIGS. 5a and 5b.

FIG. 6 shows a section of a further embodiment of a fuel injection valve 10.5 in a longitudinal section. Attached to a lower or downstream end of the nozzle body 16 is a cap 29 having a central recess for the first and second injection ports 161,162. Between the cover 29 and the nozzle body 16 there is a radially encircling, toroidal intermediate space 291 . The nozzle body 16 has two bores 37 which are designed to feed and discharge coolant into the intermediate space 291 .

Fuel injection valve 10.5 has two flow channels 36.1 and 36.2 of high-pressure chamber 26. The plunger 40 of the electrically actuable actuator assembly 38 and the low-pressure outlet 42 are arranged centered on the longitudinal axis L. A shaft 76 of a mushroom-shaped intermediate valve member 78 is guided in the intermediate part 66 . A head 80 of the intermediate valve member 78 integrally formed with the stem 76 is located in the control chamber 70 and interacts with its side facing the intermediate part 66 with the intermediate part 66, the flat end face of which forms an annular intermediate valve seat. In the intermediate part 66 runs a fuel high-pressure inlet 86, which with the High-pressure space 26 is connected and comprises a horizontal bore and a vertical bore. In the closed position of the intermediate valve member 78, the vertical bore opens into an annular gap space which is formed between the intermediate part 66 and the head 80 and is radially delimited by a first and a second annular sealing surface. In the open position, the intermediate valve member 78 releases a second connection between the high-pressure fuel inlet 86 and the valve chamber 44 through an inlet (not shown in FIG. 6), so that the valve chamber 44 or the blind hole 92 can be flooded with fuel. The inlet (not shown in Figure 6) opens with a first end into a blind hole 92 running through the stem 76, which is part of the valve chamber 44, and with a second end on the outside of the intermediate valve member 78 at a line on which the stem 76 to the head 80 connects. A throttle passage 90 is formed on the head 80 and runs from the end face of the head 80 facing the control piston 68 to the blind hole 92 and connects the valve chamber 44 to the control chamber 70 . When the intermediate valve member 78 is in the closed position, the first connection between the high-pressure fuel inlet 86 and the control chamber 70 is interrupted and the control chamber 70 is separated from the valve chamber 44 except for the throttle passage 90 . In the closed position of the intermediate valve member 78, the second connection between the high-pressure fuel inlet 86 and the valve chamber 44 is also interrupted. The structure of the intermediate valve of the hydraulic control device formed by the intermediate valve member 78 together with the intermediate valve seat formed on the intermediate part 66 can therefore correspond to the structure of the intermediate valve in WO2021/165275 A1. FIG. 7a shows a detail of a further embodiment of a fuel injector 10.6 in a longitudinal section. Fuel injection valve 10.6 includes a nozzle body 16 with a nozzle chamber 165, which is connected to a high-pressure chamber 26. An injection valve member 56 has a main needle 57 with a control piston 68 which is guided in a guide part 64 with a sliding fit.

The injection valve member 56 further includes a needle sleeve 58 disposed at a downstream end of the main needle 57 and a needle pin 59 partially disposed within the needle sleeve 58 . The needle pin 59 has a mounting shank 596 which is fixed in a sleeve-shaped end 572 of the main needle 57 via a press fit and is therefore arranged in a fixed position with respect to the main needle 57 . A washer 576 is disposed in the axial direction between the mounting shank 596 of the needle pin 59 and the main needle 57 in the sleeve-shaped end 572 . Upstream of washer 576 is bore 575 . The needle sleeve 58 is arranged at the downstream end of the main needle 57, the needle sleeve 58 being adjustably arranged with respect to the main needle 57 and the needle pin 59 fixed to the main needle 57. A retaining spring 52 is arranged between the main needle 57 and the needle sleeve 58 and applies a retaining force in the downstream direction to the needle sleeve 58 when the injection valve member 56 is in the open position.

The hydraulic control device for controlling the movement of the injection valve member 56 along the longitudinal axis L essentially corresponds to that in Figure 6 shown embodiment of the fuel injector

10.5.

Fuel injector 10.6 has first injection openings 161 and second injection openings 162, first injection openings 161 having a larger minimum diameter than the minimum diameter of second injection openings 162. The first injection openings 161 are separated from the high-pressure chamber 26 and connected to the high-pressure chamber 26 by means of a sealing interaction with the needle sleeve 58 . The second injection openings 162 are separated from the high-pressure chamber 26 and connected to the high-pressure chamber 26 by sealing cooperation with the needle pin 59 .

FIG. 7b shows an enlarged downstream region of the embodiment of fuel injector 10.6 compared to FIG. 7a. The needle sleeve 58 has a first valve sealing surface 581 which cooperates in a sealing manner with the first injection valve seat 163 of the nozzle body 16 for connecting and separating the first injection openings 161 with and from the high-pressure chamber 26 and the nozzle chamber 165, respectively. In relation to first valve sealing surface 581, needle sleeve 58 is designed with an inner and outer valve sealing surface and a radially circumferential, trough-shaped groove similar to the needle sleeve of the embodiment of fuel injector 10.3 shown in FIGS. 4a and 4b. Furthermore, the needle sleeve 58 also has an outer, radially circumferential recess 584 and an inner, radially circumferential recess 583 . The needle pin 59 has a second valve sealing surface 591 which cooperates in a sealing manner with the second injection valve seat 164 of the nozzle body 16 for connecting and disconnecting the second injection openings 162 to and from the high-pressure chamber 26 and the nozzle chamber 165, respectively. The second injection openings 162 emanate from a part 166 of the nozzle space 165 which is arranged below or downstream of the second injection valve seat 164 . It is conceivable that in certain embodiments, the second injection openings 162 originate from the second injector seat 164 (comparable to the first injection openings 161, which originate from the first injector seat 163), in particular with a small volume of the part 166.

An intermediate space 168 is arranged between the needle pin 59 and the needle sleeve 58 both in the intermediate position and in the closed position of the injection valve member 56 and is connected to the high-pressure chamber 26 via a transverse bore 5813 in the needle sleeve 58 . In the intermediate position of the injection valve member 56 , fuel that is under high-pressure chamber pressure can therefore pass from the intermediate space 168 into the second injection openings 162 .

The needle pin 59 has a profile that tapers in the direction of the second valve sealing surface 591 and has a number of gradations. A first step 597 creates a portion of the intermediate space 168 between the needle sleeve 58 and the needle pin 59. The needle pin 59 further has a guide section 592 on which a lower guide passage 582.1 of the needle sleeve 58 is guided with a sliding fit. Upstream of the guide portion 592 is a collar portion 593 which is a smaller radial diameter than the guide portion 592 has. The collar section 593 protrudes through an upper guide passage 582.2, which is formed by an axial bore of the needle sleeve 58. The radial play between the collar section 593 and the upper guide passage 582.2 is greater than the radial play between the guide section 592 and the lower guide passage 582.1. The needle sleeve 58 has a cup-shaped form, with the upper guide passage 582.2 being arranged in the base of the cup-shaped needle sleeve 58, so that the collar section 593 of the needle pin 59 protrudes through the base of the cup-shaped needle sleeve 58.

The retaining spring 52 is radially retained at its upstream end by the sleeve-shaped end 572 of the main needle 57 and at its downstream end radially by a retaining portion 5812 of the needle sleeve 58 with a reduced radial diameter. The needle sleeve 58 is guided on the needle pin 59 so that it can be adjusted in the axial direction relative to the main needle 57, with the retaining spring 52 acting on the needle sleeve 58 with a retaining force acting in the downstream direction.

The needle sleeve 58 has a sleeve shoulder 586 and the needle pin 59 has a needle shoulder 594 . In the closed position of the injection valve member 56, the needle shoulder 594 and the sleeve shoulder 586 are arranged at an axial distance from one another, which increases the stroke of the needle pin 59 for the movement from the closed position to the intermediate position with the stationary position of the needle sleeve 58, in which the first injection openings 161 are separated from the high-pressure chamber 26 are separated. In the open position of the injection valve member 56, the retaining spring 52 presses the sleeve shoulder 586 of the needle sleeve 58 against the needle shoulder

594 of the needle pin 59.

The injection valve member 56 is formed in a closed position, which is shown in Figure 7b, the first injection openings 161 with the needle sleeve 58 through sealing interaction of the first valve sealing surface 581 with the first injection valve seat 163 and the second injection openings 162 with the needle pin 59 through sealing interaction of the second valve sealing surface 591 with the second injection valve seat 164 from the high-pressure chamber 26. By raising the needle pin 59 from the second injector seat 164, the intermediate position can be reached in which the second injection openings 162 are opened and connected to the high-pressure chamber 26, while the needle sleeve 58 remains in the position in which the needle sleeve 58 rests on the first injector seat 163 presses and the first injection openings 161 are thereby separated from the high-pressure chamber 26. By further raising the needle pin 59, the needle sleeve 58 is also raised due to an interlocking of the sleeve shoulder 586 of the needle sleeve 58 and the needle shoulder 594 of the needle pin 59, so that the open position is reached, in which the first injection openings 161 and the second injection openings 162 are released and are connected to the high-pressure chamber 26 . The raising and lowering of the needle pin 59 and the needle sleeve 58 is achieved by adjusting the main needle 57 and the injection valve member 56, respectively. Accordingly, by adjusting the injection valve member 56 either the second injection ports 162 for a pilot or Pilot jet injection or the first and the second injection openings 161, 162 are opened for a main injection of liquid fuel from the high-pressure chamber 26 into the combustion chamber of the internal combustion engine.

Claims

patent claims

1. Fuel injection valve (10.1-10.6) for intermittently injecting fuel into the combustion chamber of an internal combustion engine, comprising a housing (12) defining a longitudinal axis (L), having a high-pressure fuel inlet and a nozzle body (16) having a nozzle space (165) and a first and a second injection valve seat (163, 164), the nozzle body (16) having at least one first injection opening (161) emanating from the nozzle chamber (165) and at least one second injection opening (162) emanating from the nozzle chamber (165) for injecting fuel into the combustion chamber of the internal combustion engine, a high-pressure chamber (26) which is arranged in the housing (12) and runs from the high-pressure fuel inlet to the nozzle chamber (165), an injection valve member (56) which is adjustably arranged in the housing (12) in the direction of the longitudinal axis (L), a compression spring ( 63) which acts on the injection valve member (56) with a closing force directed towards the first injection valve seat (163), a hydraulic control device (72) for controlling the movement of the injection valve member (56) along the longitudinal axis (L), wherein the injection valve member (56) has a main needle (57) with a control piston (68) which is arranged on an end of the main needle facing away from the first injection valve seat (163) and is guided in a sliding fit in a guide part (64), a needle sleeve (58), which is arranged on an end of the main needle (57) facing the first injection valve seat (163) and has a needle pin (59) arranged at least partially in the needle sleeve (58), the needle sleeve (58) having a first valve sealing surface (581), which is designed to cooperate sealingly with the first injection valve seat (163) for connecting and disconnecting the at least one first injection opening (161) to and from the high-pressure chamber (26), the needle pin (59) having a second valve sealing surface (591) which is designed to cooperate sealingly with the second injection valve seat (164) for connecting and disconnecting the at least one second injection opening (162) to and from the high-pressure chamber (26). Fuel injection valve (10.1-10.5) according to Claim 1, characterized in that the at least one first injection opening (161) and the at least one second injection opening (162) are different

have a minimum diameter. Fuel injection valve (10.1-10.6) according to claim 1 or 2, characterized in that the at least one second injection opening (162) downstream of the at least one first injection opening (161) is arranged.

4. Fuel injection valve (10.1-10.5) according to one of the preceding claims, characterized in that the needle sleeve (58) is attached to the main needle (57) and the needle pin (59) in the needle sleeve (58) along the longitudinal axis (L) and is adjustable relative to the main needle (57).

5. Fuel injection valve (10.1-10.5) according to claim 4, characterized in that the at least one first injection opening (161) has a smaller

Minimum diameter than the minimum diameter of the at least one second injection port (162).

6. Fuel injection valve (10.1-10.5) according to claim 4 or 5, characterized in that the injection valve member (56) is designed, in a closed position, the at least one first injection opening (161) with the needle sleeve (58) and the at least one second injection opening ( 162) with the needle pin (59) from the high-pressure chamber (26), in an intermediate position to connect the at least one first injection opening (161) by lifting the needle sleeve (58) from the first injection valve seat (163) with the high-pressure chamber (26) and the to separate at least one second injection opening (162) with the needle pin (59) from the high-pressure chamber (26), in an open position, the at least one first injection opening (161) by lifting the needle sleeve (58) from the first injection valve seat (163) and the at least one second injection opening (162) by lifting the needle pin (59) from the second injection valve seat (164) with the high-pressure chamber ( 26) to connect. Fuel injector (10.1-10.5) according to Claim 6, characterized in that a stroke (H) of the needle sleeve (58) is provided from the closed position to the intermediate position when the needle pin (59) is in a stationary position, the stroke (H) preferably being between 0.1 to is 0.2 mm. Fuel injection valve (10.1-10.5) according to Claim 6 or 7, characterized in that the needle sleeve (58) has a sleeve shoulder (586) and the needle pin (59) has a needle shoulder (594), the sleeve shoulder (586) and the needle shoulder (594 ) between the

The intermediate position and the open position can be engaged with one another in such a way that the needle pin (59) can be lifted from the second injection valve seat (164) through the needle sleeve (58). Fuel injector (10.1-10.5) according to Claim 8, characterized in that the needle pin (59) has a guide section (592) downstream of the needle shoulder (594) and a collar section (593) upstream of the needle shoulder (594), with between the collar section (593 ) and the needle sleeve (58) there is greater radial play than between the guide section (592) and the needle sleeve

(58). Fuel injection valve (10.1-10.5) according to one of Claims 4 to 9, characterized in that between the needle pin (59) and the main needle (57) is connected to the high-pressure chamber (26) and is axially separated from the needle pin (59) and the main needle ( 57) limited needle control space (51) is arranged. Fuel injection valve (10.1-10.3, 10.5) according to

Claim 10, characterized in that the main needle (57) has a recess at the end facing the first injection valve seat (163), a radial side wall (572) of the recess at least partially radially delimiting the needle control chamber (51) and preferably a transverse bore (571) in the radial side wall (572) of the recess connects the needle control chamber (51) to the high-pressure chamber (26). Fuel injection valve (10.4) according to Claim 10 or 11, characterized in that the needle control chamber (51) is at least partially delimited radially by the needle sleeve (58) and is preferably connected to the high-pressure chamber (26) via a transverse bore (5811) in the needle sleeve (58). connected is. Fuel injector (10.1-10.5) according to one of Claims 10 to 12, characterized in that a retaining spring (52) is arranged in the needle control chamber (51) and holds the needle pin (59) with a retaining force directed towards the second injector seat (164). applied. Fuel injection valve (10.1-10.5) according to Claims 8 and 13, characterized in that in the open position the retaining spring (52) presses the needle shoulder (594) of the needle pin (59) against the sleeve shoulder (586) of the needle sleeve (58). Fuel injection valve (10.1-10.5) according to one of Claims 4 to 14, characterized in that the needle sleeve (58) at the end of the main needle (57) which faces the first injector seat (163) and which is sleeve-shaped or knob-shaped, preferably via a press fit, is attached. Fuel injector according to one of Claims 4 to 14, characterized in that the needle sleeve is fastened by laser welding, via a thread or by brazing to the end of the main needle which faces the first injector seat and which is sleeve-shaped or nub-shaped. Fuel injection valve according to one of Claims 4 to 14, characterized in that the needle sleeve is constructed in one piece with the main needle. Fuel injection valve (10.6) according to one of

Claims 1 to 3, characterized in that the needle pin (59) is attached to the main needle (57) and the needle sleeve (58) is adjustably guided on the needle pin (59) along the longitudinal axis (L) and relative to the main needle (57). . Fuel injection valve (10.6) according to claim 18, characterized in that the at least one second Injection opening (162) a smaller one

Minimum diameter than the minimum diameter of the at least one first injection port (161). Fuel injection valve (10.6) according to Claim 18 or 19, characterized in that the injection valve member (56) is designed to connect the at least one first injection opening (161) with the needle sleeve (58) and the at least one second injection opening (162) with the needle sleeve (58) in a closed position separating the needle pin (59) from the high-pressure chamber (26), connecting the at least one second injection opening (162) to the high-pressure chamber (26) by lifting the needle pin (59) from the second injection valve seat (164) in an intermediate position and connecting the at least one first injection opening (161) with the needle sleeve (58) from the high-pressure chamber (26), in an open position the at least one first injection opening (161) by lifting the needle sleeve (58) from the first injection valve seat (163) and the at least one second injection opening (162) to be connected to the high-pressure chamber (26) by lifting the needle pin (59) from the second injection valve seat (164). Fuel injector (10.6) according to Claim 20, characterized in that a stroke (H) of the needle pin (59) is provided from the closed position to the intermediate position when the needle sleeve (58) is in a stationary position, the stroke (H) preferably being between 0.1 and 0.2 mm amounts.

22. The fuel injector (10.6) according to claim 20 or 21, characterized in that the needle sleeve (58) has a sleeve shoulder (586) and the needle pin (59) has a needle shoulder (594), the sleeve shoulder (586) and the needle shoulder (594 ) between the

Intermediate position and the open position can be engaged in one another in such a way that the needle sleeve (58) can be lifted from the first injection valve seat (163) by the needle pin (59).

23. The fuel injector (10.6) according to claim 22, characterized in that the needle pin (59) has a guide section (592) downstream of the needle shoulder (594) and a collar section (593) upstream of the needle shoulder (594), with between the collar section (593 ) and the needle sleeve (58) has a greater radial play than between the guide section (592) and the needle sleeve (58) and the collar section (593) has a smaller radial diameter than the guide section (592).

24. Fuel injection valve (10.6) according to one of

Claims 18 to 23, characterized in that a retaining spring (52) is arranged in the axial direction between the main needle (57) and the needle sleeve (58), which holds the needle sleeve (58) in a direction towards the first injection valve seat (163). holding force applied.

25. Fuel injection valve (10.6) according to claim 24, characterized in that the retaining spring (52) in the In the open position, the sleeve shoulder (586) of the needle sleeve (58) presses against the needle shoulder (594) of the needle pin (59).

26. Fuel injection valve (10.6) according to one of

Claims 18 to 25, characterized in that the needle pin (59) is attached to the end of the main needle (57) facing the first injection valve seat (163), which is sleeve-shaped or nub-shaped, preferably via a press fit.

27. Fuel injection valve according to one of claims 18 to 25, characterized in that the needle pin is fastened by laser welding, via a thread or by brazing on the end of the main needle which faces the first injector seat and which is sleeve-shaped or nub-shaped.

28. Fuel injection valve (10.6) according to one of

Claims 18 to 27, characterized in that in the intermediate position and/or the closed position between the needle pin (59) and the needle sleeve (58) an intermediate space (168) is formed in a region adjoining the second injection valve seat (164), which space communicates with the High-pressure chamber (26), preferably via a transverse bore (5813) in the needle sleeve (58) is connected.

29. The fuel injector (10.6) according to claim 28, characterized in that the needle pin (59) has a profile that tapers toward the second valve sealing surface (591), the tapering profile preferably having at least one step (597). Fuel injection valve (10.1-10.6) according to one of the preceding claims, characterized in that the at least one first injection opening (161) is arranged radially further from the longitudinal axis (L) than the at least one second injection opening (162). Fuel injector (10.1-10.3, 10.5, 10.6) according to one of the preceding claims, characterized in that the first injector seat (163) is conical with a first opening angle and the second injector seat (164) is conical with a second opening angle and downstream of the first injection valve seat (163), the first opening angle being greater than the second opening angle. Fuel injection valve (10.4) according to one of

Claims 1 to 30, characterized in that the first injection valve seat (163) is conical with a first opening angle and the second injection valve seat (164) is conical with a second opening angle and is arranged downstream of the first injection valve seat (163), the first and the second opening angle are the same. Fuel injector (10.1-10.3, 10.5, 10.6) according to one of the preceding claims, characterized in that the needle sleeve (58) has an outer radially circumferential recess (584) on a radially outer side surface adjacent to the first valve sealing surface (581). Fuel injection valve (10.2, 10.2, 10.5, 10.6) according to Claim 33, characterized in that an outer radially encircling collar (587) is formed between the outer radially encircling recess (584) and the first valve sealing surface (581). Fuel injector (10.2, 10.2, 10.5, 10.6) according to Claim 33 or 34, characterized in that the outer radially circumferential recess (584) forms an outer conical end surface (585) of the radially outer side surface, which is arranged facing away from the first valve sealing surface (581). is. Fuel injector (10.1, 10.2, 10.3, 10.5, 10.6) according to one of the preceding claims, characterized in that the needle sleeve (58) has an inner radially circumferential recess (583) on a radially inner side surface adjacent to the first valve sealing surface (581). Fuel injector (10.3, 10.6) according to Claim 36, characterized in that an inner, radially encircling collar (589) is formed between the inner, radially encircling recess (583) and the first valve sealing surface (581). Fuel injector (10.3, 10.6) according to Claim 36 or 37, characterized in that the inner radially circumferential recess (583) forms an inner conical closing surface (588) of the radially inner side surface, which is arranged facing away from the first valve sealing surface (581). Fuel injector (10.2, 10.3, 10.5, 10.6) according to one of the preceding claims, characterized in that the first valve sealing surface (581) has an inner valve sealing surface (581.1) and an outer valve sealing surface (581.2) and the needle sleeve (58) on one of the first The end facing the injection valve seat (163) has a radially circumferential, trough-shaped groove (5810), the inner and the outer valve sealing surface (581.1, 581.2) adjoining the trough-shaped groove (5810). Fuel injection valve (10.2, 10.3, 10.5, 10.6) according to Claim 39, characterized in that the at least one first injection opening (161) is arranged in such a way that when the first valve sealing surface (581) interacts with the first injection valve seat (163) to separate the at least one first injection opening (161) from the high-pressure chamber (26), the trough-shaped groove (5810) is connected to the at least one first injection opening (161). Fuel injection valve (10.4) according to one of the preceding claims, characterized in that the at least one first injection opening (161) extends from the nozzle chamber (165) via a radially encircling, trough-shaped nozzle body groove (167). Fuel injection valve (10.1-10.5) according to one of the preceding claims, characterized in that the at least one first injection opening (161) has a first opening section starting from the nozzle chamber (165). (161.1) and one on the first opening section

(161.1) adjoining second opening section

(161.2), the diameter of the second opening section (161.2) being greater than the diameter of the first opening section (161.1). Fuel injection valve (10.5, 10.6) according to one of the preceding claims, characterized in that a cover (29) with a central recess for the at least one first and the at least one second injection openings (161, 162) is provided at a lower end of the nozzle body (16). is fixed in such a way that between the

cover (29) and the nozzle body (16), a radially circumferential intermediate space (291) is formed, the nozzle body (16) having two bores (37) which are designed to feed and discharge coolant into the intermediate space (291). Fuel injector (10.1-10.6) according to one of the preceding claims, characterized in that the fuel injector further comprises: an intermediate part (66) which, together with the guide part (64) and the control piston (68), delimits a control chamber (70), the hydraulic control device (72) is designed to control the movement of the injection valve member (56) along the longitudinal axis (L) by changing the pressure in the control chamber (70), the hydraulic control device (72) a

Intermediate valve (83) with a mushroom-shaped design Intermediate valve member (78), which has a shank (76) guided in a guide recess of the intermediate part (66) and a head (80), and having a head formed on a side of the intermediate part (66) facing the head (80). (80) interacting intermediate valve seat, wherein the intermediate valve member (78) releases a first connection between a high-pressure fuel inlet (86) connected to the high-pressure chamber (26) and the control chamber (70) when the intermediate valve member (78) is in an open position, and in a closed position of the Intermediate valve member (78) interrupts the first connection between the high-pressure fuel inlet (86) and the control chamber (70) and separates the control chamber (70) from a valve chamber (44) - with the exception of a throttle passage (90), an electrically actuatable actuator arrangement (38) for connecting the valve chamber (44) to and separating the valve chamber (44) from a low-pressure fuel return (46), the intermediate valve member (78) forming a second connection between the high-pressure fuel inlet (86) and the valve chamber when the intermediate valve member (78) is in the open position (44) releases and in the closed position of the intermediate valve member (78) interrupts the second connection between the high-pressure fuel inlet (86) and the valve chamber (44).