Fuel injection valve for internal combustion engines

Abstract

Fuel injection valve (10.1-10.6) for intermittent injection of fuel into the combustion chamber of an internal combustion engine, comprising a housing (12) defining a longitudinal axis (L), which has a high-pressure fuel inlet and a nozzle body (16) with a nozzle chamber (165) and a first and a second injection valve seat (163, 164), wherein the nozzle body (16) has at least a first injection opening (161) extending from the nozzle chamber (165) and at least a second injection opening (162) extending from the nozzle chamber (165) for injecting fuel into the combustion chamber of the internal combustion engine, a high-pressure chamber (26) arranged in the housing (12) extending from the high-pressure fuel inlet to the nozzle chamber (165), an injection valve element (56) arranged adjustably in the housing (12) in the direction of the longitudinal axis (L), a compression spring (63),which applies a closing force to the injector element (56) directed towards the first injector seat (163), a hydraulic control device (72) for controlling the movement of the injector element (56) along the longitudinal axis (L), wherein the injector element (56) has a main needle (57) with a control piston (68) which is arranged at an end of the main needle facing away from the first injector seat (163) and is guided in a sliding fit in a guide part (64), a needle sleeve (58) which is arranged at an end of the main needle (57) facing towards the first injector seat (163), and a needle pin (59) which is arranged at least partially in the needle sleeve (58), wherein the needle sleeve (58) has a first valve sealing surface (581) which is formed,with the first injection valve seat (163) to connect and disconnect the at least one first injection port (161) with and from the high-pressure chamber (26) in a sealing manner, wherein the needle pin (59) has a second valve sealing surface (591) which is designed to connect and disconnect the at least one second injection port (162) with and from the high-pressure chamber (26) in a sealing manner.

Description

Field of the invention The present invention relates to a fuel injection valve for intermittent injection of fuel into the combustion chamber of an internal combustion engine. Background of the invention Fuel injectors are used for the direct injection of fuel into the combustion chamber of an internal combustion engine, particularly in 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 some commercial vehicles. One challenge in dual-fuel systems is the required separate injection of fuel, such as diesel or marine diesel oil, as the ignition jet when operating with gas as the main fuel. In particular, ignition jet injection of fuel requires different injection parameters than conventional fuel injection, such as injection quantity, injection pressure, injection configuration, etc. The provision of different injection parameters is also desired for other purposes such as pilot injections or pre-injections in addition to the main injection, which 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 configured to produce two different spray patterns via independently controlled adjacent needle valve elements. 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 having a spray configuration configured to provide a first fuel spray pattern, and a second nozzle having a spray configuration configured to provide a second fuel spray pattern different 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 comprises a first needle valve element positioned within the hollow interior of the injector body, the first needle valve element corresponding to the first nozzle, and a second needle valve element positioned within the hollow interior of the injector body and corresponding to the second nozzle. The second needle valve element is spaced apart from and 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. Description of the invention Given the increased 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 injector having the features of the independent claim. Advantageous embodiments of the invention are provided in the dependent claims and in the present description and figures. The invention relates to a fuel injector for the intermittent injection of fuel into the combustion chamber of an internal combustion engine, comprising a housing defining a longitudinal axis, a high-pressure fuel inlet, and a nozzle body with a nozzle chamber and a first and a second injection valve seat. The nozzle body has at least one first injection opening extending from the nozzle chamber and at least one second injection opening extending 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, which runs from the high-pressure fuel inlet to the nozzle chamber. Furthermore, an injection valve member is arranged in the housing and can be adjusted in the direction of the longitudinal axis. The fuel injector further comprises a compression spring, which applies a closing force to the injection valve member directed toward 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 fixedly supported relative to the housing. The fuel injection valve further comprises a hydraulic control device for controlling the movement of the injection valve member along the longitudinal axis, wherein the injection valve member has a main needle with a control piston which is arranged at an end of the main needle facing away from the first injection valve seat and is guided in a guide part with a sliding fit, a needle sleeve which is arranged at an end of the main needle facing the first injection valve seat, and a needle pin arranged at least partially in the needle sleeve. The needle sleeve has a first valve sealing surface designed to sealingly cooperate with the first injection valve seat for connecting and separating the at least one first injection opening to and from the high-pressure chamber. The needle pin has a second valve sealing surface designed to sealingly cooperate with the second injection valve seat for connecting and separating the at least one second injection opening 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 chamber and for separating the at least one first injection opening from the high-pressure chamber and the needle pin for connecting the at least one second injection opening to the high-pressure chamber and for separating the at least one second injection opening from the high-pressure chamber, 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 separation of the at least one first injection opening to 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 separation of the at least one second injection opening to and from the high-pressure chamber. In particular, the at least one first injection opening can be separated from the high-pressure chamber by the needle sleeve sealingly engaging the first injection valve seat via the first valve sealing surface. Correspondingly, the at least one second injection opening can be separated from the high-pressure chamber by the needle pin sealingly engaging 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 orAt least one second injection port is connected to the high-pressure chamber. The interaction can therefore include both a pressing action and a lifting action. The needle pin and the needle sleeve can be adjusted relative to each other along the longitudinal axis. In particular, the needle sleeve can be arranged stationary relative to the main needle and the needle pin can be arranged adjustable relative to the main needle, or alternatively, the needle pin can be arranged stationary relative to the main needle and the needle sleeve can be arranged adjustable relative 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 adjusted by selectively connecting and / or disconnecting the at least one first and / or at least one second injection opening, can be achieved through the respective interaction of the needle sleeve or needle pin with the first or second injection valve seat. The needle sleeve also offers the advantage that the primary pressure drop across the first injection valve seat can be utilized, for example, to achieve improved pre-injection with the desired atomization. The hydraulic control device can precisely and reliably control and adjust the injection valve member or the main needle. The fuel injection valve 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 optimal engine combustion using the same injection valve member, utilizing the at least one first injection opening and the at least one second injection opening. Preferably, the fuel injection valve has a plurality, eg two, three, four, five, six or more, of radially symmetrically arranged first injection openings, preferably at a first height, and a plurality, eg two, three, four, five, six or more, of radially symmetrically arranged second injection openings, preferably at a second height. In one embodiment, the at least one first injection opening and the at least one second injection opening have different minimum diameters. By selecting different minimum diameters for the at least one first injection port and the at least one second injection port, different injection cross-sections can be provided for different injection purposes. For example, a smaller minimum diameter can be selected for ignition jet injection or pilot injection. A larger minimum diameter, on the other hand, can be selected for use as a main injector for diesel, marine diesel, or heavy fuel oil. With a plurality of first injection openings, the first injection openings preferably have the same 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. Accordingly, with a plurality of second injection openings, their minimum diameters are preferably the same and particularly preferably their geometries are the same. However, configurations with different geometries and / or minimum diameters are also conceivable for the plurality of second injection openings. In one embodiment, 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, an improved selective connection and separation of the at least one first injection opening and the at least one second injection opening with and from the high-pressure chamber can be achieved by means of this spatial configuration of the at least one first injection opening and the at least one second injection opening. In one embodiment, the needle sleeve is attached to the main needle and the needle pin is guided in the needle sleeve along the longitudinal axis and adjustable relative to the main needle. In one embodiment, 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 a diesel ignition jet injection in order to ignite a lean (natural) gas / air mixture or, for example, for a pre-injection in diesel or heavy oil operation. Preferably, the starting point from which the at least one first injection opening extends from the nozzle chamber is radially further away from the longitudinal axis of the housing than the starting point from which the at least one second injection opening extends from the nozzle chamber. In one embodiment, 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, to connect the at least one first injection opening with the high-pressure chamber by lifting the needle sleeve from the first injection valve seat and to separate the at least one second injection opening with the needle pin from the high-pressure chamber in an intermediate position, and to connect the at least one first injection opening with the needle pin by lifting the needle sleeve from the first injection valve seat and the at least one second injection opening with the needle pin by lifting the needle pin from the second injection valve seat in an open position. The fuel injector and the injector member can therefore provide at least three (connection / disconnection) configurations 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 first injection opening has a smaller minimum diameter than the at least one second injection opening. Embodiments 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 below, among other things. The open position can, for example, be used in diesel orHeavy fuel oil operation can be used 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 fuel oil as the main fuel. In this embodiment, the fuel injector can therefore provide an ignition 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 injector offers the advantage that it can also be used for diesel or heavy fuel oil operation. In this embodiment, a pre-injection or pilot injection can be provided via the at least one first injection opening, which has a smaller minimum diameter than the at least one second injection opening, and the main injection can be provided via the opening of the at least one first and at least one second injection opening. In diesel or heavy fuel oil operation, in one variant, the at least one first injection port, which has a smaller minimum diameter than the at least one second injection port, can be opened for a pre-injection and closed again after the pre-injection. After a certain time interval, the at least one first injection port and the at least one second injection port can then be opened for the main injection. In a further variant, a staged injection can be implemented in diesel or heavy fuel oil operation. For example, the at least one first injection port, which has a smaller minimum diameter than the at least one second injection port, can be opened for a pre-injection, and the at least one second injection port can be additionally 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 as a pilot jet injector on the one hand and as a main injector with variably adjustable pre-injection on the other hand. Preferably, the needle pin with the second valve sealing surface 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 with the needle pin in a fixed position, wherein the stroke is preferably 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 fixed 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 short stroke of the needle sleeve with the needle pin in a fixed 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, wherein the sleeve shoulder and the needle shoulder can engage with each other between the intermediate position and the open position such that the needle pin can be lifted from the second injection valve seat by the needle sleeve. The needle pin can therefore be adjusted by controlling the main needle or the needle sleeve, which is permanently connected to the main needle, via the hydraulic control device. Furthermore, with the sleeve shoulder and the needle shoulder, the travelable stroke of the needle sleeve can be defined by the axial distance between the sleeve shoulder and the needle shoulder in the closed position when the needle pin is in a fixed position, in which the at least one second injection opening is separated from the high-pressure chamber. In one embodiment, the needle pin has a guide section downstream of the needle shoulder and a collar section upstream of the needle shoulder, wherein there is a greater radial play between the collar section and the needle sleeve than between the guide section and the needle sleeve. The needle pin is preferably guided in the needle sleeve via a sliding fit of the guide section. With the larger radial play between the collar section and the needle sleeve, double guidance can be avoided. The collar section is preferably formed upstream of the guide section adjacent to 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. Accordingly, the needle sleeve preferably has a lower guide passage for guiding the guide section and an upper guide passage for receiving the collar section, wherein the upper guide passage has a larger radial diameter than the lower guide passage.The upper guide passage preferably borders on 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, said control chamber being connected to the high-pressure chamber and axially delimited by the needle pin and the main needle. The needle control chamber, which is axially defined by the needle pin and the main needle, allows the needle pin to be adjusted along its longitudinal axis relative to the main needle. Since the needle control chamber is connected to the high-pressure chamber, the pressure of the high-pressure chamber can also act on the needle pin at the end of the needle pin facing away from the second injection valve seat, in order to close the at least one second injection opening or to separate it from the high-pressure chamber. In one embodiment, the main needle has a recess at the end facing the first injection valve seat, wherein a radial side wall of the recess at least partially radially delimits the needle control chamber and preferably a transverse bore in the radial side wall of the recess connects the needle control chamber to the high-pressure chamber. Due to the radial side wall, which at least partially radially delimits the needle control chamber, the main needle can have a sleeve-shaped end at its end facing the first injection valve seat, which is defined by the recess. Preferably, the needle sleeve is attached to the sleeve-shaped end of the main needle, e.g., via a press fit. In one embodiment, the needle control chamber is at least partially radially delimited 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 limited 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 applies a holding force to the needle pin directed towards the second injection valve seat. 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 with its upstream end and the needle pin with its downstream end. The retaining spring is preferably preloaded with a biasing force and is additionally compressed during the transition from the open position to the closed position, so that the retaining spring can apply a holding force to the needle pin directed against the second injection valve seat. In one embodiment, the retaining spring presses the needle shoulder of the needle pin against the sleeve shoulder of the needle sleeve in the open position. 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 end is sleeve-shaped or knob-shaped, preferably via a press fit. In one embodiment, the needle sleeve is attached to the end of the main needle facing the first injection valve seat, which end is sleeve-shaped or knob-shaped, by laser welding, via a thread or by brazing. In main needle configurations with a knob-shaped end facing the first injection valve seat, the knob-shaped end can have an upper knob and a lower knob adjacent to the upper knob with a smaller radial diameter. The lower knob can serve to radially hold the retaining spring at its upstream end. In one embodiment, the needle sleeve is formed integrally with the main needle. In one embodiment, the needle pin is attached to the main needle and the needle sleeve is guided on the needle pin along the longitudinal axis and adjustable relative to the main needle. In one embodiment, 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 a diesel ignition jet injection in order to ignite a lean (natural) gas / air mixture or, for example, for a pre-injection in diesel or heavy oil operation. In one embodiment, 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, to connect the at least one second injection opening with the high-pressure chamber by lifting the needle pin from the second injection valve seat in an intermediate position and to separate the at least one first 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. The fuel injector and the injection valve member can therefore provide at least three (connection / disconnection) configurations, 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 fuel 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 fuel oil operation to open both the at least one first and the at least one second injection opening and to use the fuel injector as the main injector for diesel or heavy fuel oil as the main fuel. In this embodiment, the fuel injection valve can therefore provide an ignition jet 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 injector offers the advantage that it can also be used for diesel or heavy fuel oil operation. In this embodiment, 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 at least one second injection opening. In diesel or heavy fuel oil operation, in one variant, the at least one second injection port, which has a smaller minimum diameter than the at least one first injection port, can be opened for a pre-injection and closed again after the pre-injection. After a certain time interval, the at least one first injection port and the at least one second injection port can then be opened for the main injection. In a further variant, a staged injection can be implemented in diesel or heavy fuel oil operation. For example, the at least one second injection port, which has a smaller minimum diameter than the at least one first injection port, can be opened for a pre-injection, and the at least one first injection port can be opened additionally for a main injection. In one embodiment, a stroke of the needle pin is provided from the closed position to the intermediate position with the needle sleeve in a fixed position, wherein the stroke is preferably 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 while the needle sleeve is in a fixed 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 short stroke of the needle pin while the needle sleeve is in a fixed 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, wherein the sleeve shoulder and the needle shoulder can engage with each other 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 via the hydraulic control device. Furthermore, with the sleeve shoulder and the needle shoulder, the travelable stroke of the needle pin can be defined by the axial distance between the sleeve shoulder and the needle shoulder in the closed position when the needle sleeve is in a fixed position, in which the at least one first injection opening is separated from the high-pressure chamber. In one embodiment, the needle pin has a guide section downstream of the needle shoulder and a collar section upstream of the needle shoulder, wherein there is a greater radial play between the collar section and the needle sleeve 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 on the needle pin via a sliding fit of the guide section. With the greater radial play between the collar section and the needle sleeve, double guidance can be avoided. The collar section is preferably formed upstream of the guide section adjacent to the guide section, so that the needle shoulder is formed at the transition between the guide section and the collar section. Accordingly, the needle sleeve preferably has a lower guide passage, whereby it is guided on the needle pin by the guide section, and an upper guide passage for receiving the collar section, wherein the upper guide passage has a smaller radial diameter than the lower guide passage. The upper guide passage preferably borders on the lower guide passage, so that the sleeve shoulder is formed at the transition between the lower and upper guide passages.Preferably, the upper guide passage is formed by an axial bore in the needle sleeve, through which the collar portion of the needle pin protrudes. The needle sleeve can have a cup-shaped shape, with the upper guide passage being arranged in the bottom of the cup-shaped needle sleeve, so that the needle pin, with its collar portion, protrudes through the bottom of the cup-shaped needle sleeve. In one embodiment, a retaining spring is arranged in the axial direction between the main needle and the needle sleeve, which spring applies a holding force to the needle sleeve 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 with its upstream end and the needle sleeve with its downstream end. Preferably, the retaining spring is preloaded with a biasing force and is additionally compressed during the transition from the open position to the closed position, so that the retaining spring can apply a holding force to the needle sleeve 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 facing 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 with a reduced diameter facing away from the first injection valve seat. In one embodiment, the retaining spring presses the sleeve shoulder of the needle sleeve against the needle shoulder of the needle pin in the open position. 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 knob-shaped, preferably via a press fit. In the case of a sleeve-shaped end of the main needle facing the first injection valve seat, the needle pin can have a fastening shaft at its end facing away from the second valve sealing surface, which can be received in the sleeve-shaped end of the main needle for fastening the needle pin to the main needle. In the case of a knob-shaped end of the main needle facing the first injection valve seat, the needle pin can have a fastening sleeve at its end facing away from the second valve sealing surface, into which the knob-shaped end of the main needle can be received in order to fasten the needle pin to the main needle. 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 knob-shaped, by laser welding, via a thread or by brazing. In one embodiment, in the intermediate position and / or the closed position, an intermediate space is formed between the needle pin and the needle sleeve in a region adjoining the second injection valve seat, which intermediate space is connected to the high-pressure chamber, preferably via a transverse bore in the needle sleeve. As a result, in the intermediate position, fuel under high pressure in the chamber can be injected from the intermediate space through 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 towards the second valve sealing surface, wherein the tapered profile preferably has at least one step. The gradation allows the formation of an intermediate space between the needle sleeve and the needle pin, which is connected to the high-pressure chamber, for example, via the transverse bore in the needle sleeve. Preferably, the at least one first injection opening is arranged radially further away 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, wherein the first opening angle is greater than the second opening angle. 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, wherein the first and second opening angles are the same. 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, wherein the first opening angle is smaller than the second opening angle. In one embodiment, 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 extend from a part of the nozzle chamber that is arranged below or downstream of the second injection valve seat. In certain embodiments, however, the at least one second injection opening can also extend 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. The outer radially encircling recess allows the needle sleeve to be locally provided with a reduced wall thickness in a section adjacent to the first valve sealing surface. Preferably, the outer radially encircling recess is arranged at an axial distance from the first valve sealing surface, so that the wall thickness of the needle sleeve is locally reduced. The locally reduced wall thickness can provide elasticity to the needle sleeve in the region of the first valve sealing surface, 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 could impair the sealing interaction. In one embodiment, an outer radially circumferential collar is formed between the outer radially circumferential recess and the first valve sealing surface. The outer radially circumferential collar can provide a type of spring-loaded part 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 conical end surface of the radially outer side surface, which is arranged facing away from the first valve sealing surface. In particular, the outer radially encircling collar can be delimited at least partially by the outer conical end 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 conical end surface preferably has an inclination opposite to that of the first valve sealing surface. The outer conical end surface can also improve the contact pressure of the needle sleeve against the first injection valve seat in the closed position, since the high-pressure chamber pressure can act on the outer conical end 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 encircling recess allows a distance to be created between the needle pin and the needle sleeve in an end region of the needle sleeve facing the first injection valve seat, which distance is significantly greater than the clearance of the needle pin's sliding fit. This can reduce or prevent unwanted lifting of the needle pin when the needle sleeve is lifted in designs with a needle sleeve attached to the main needle, or unwanted lifting of the needle sleeve when the needle pin is lifted in designs with a needle pin attached to the main needle, due to a radially inward force from the high-pressure chamber and a resulting clamping effect of the needle sleeve on the needle pin, during the transition from the closed position to the intermediate position.The reduction or avoidance of the clamping effect can also be achieved by a tapered profile of the needle pin or by a radially circumferential recess of the needle pin. Furthermore, the needle sleeve can be provided with a reduced wall thickness locally in a section adjacent to the first valve sealing surface by means of the inner radially encircling recess. The inner radially encircling 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 can be provided in the region of the first valve sealing surface, 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 could impair the sealing interaction. In one embodiment, an inner radially circumferential collar is formed between the inner radially circumferential recess and the first valve sealing surface. The inner radially encircling collar can provide a type of spring-loaded part 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 end surface of the radially inner side surface, which is arranged facing away from the first valve sealing surface. In particular, the inner radially encircling collar can be delimited at least partially by the inner conical end 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 an inclination corresponding to the first valve sealing surface. The inner conical end surface can also improve the contact pressure 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 conical 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 an end facing the first injection valve seat, wherein the inner and outer valve sealing surfaces adjoin 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 between the first injection valve seat and the trough-shaped groove at a pressure that is advantageously lower than the high-pressure chamber pressure. Furthermore, the inner and outer valve sealing surfaces can provide two annular sealing surfaces, thereby reducing the effective first valve sealing surface and reducing adhesion forces. In one embodiment, the at least one first injection opening is arranged such that, 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, the trough-shaped groove is in communication with the at least one first injection opening. Because the trough-shaped groove is connected to the at least one first injection opening during the sealing interaction of the first valve sealing surface with the first injection valve seat to separate the at least one first injection opening from the high-pressure chamber, ie in the closed position, it can advantageously be achieved that the combustion chamber pressure prevails in the volume formed between the first injection valve seat and the trough-shaped groove, which is lower than the high-pressure chamber pressure. The trough-shaped groove therefore allows the area in which the combustion chamber pressure prevails to be enlarged 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 chamber via a radially circumferential trough-shaped nozzle body groove. With the trough-shaped nozzle body groove, a volume can be provided in the first injection valve seat in the closed position, similar to the trough-shaped groove of the needle sleeve, in which a defined pressure prevails, corresponding to the combustion chamber pressure. In particular, the area in which the combustion chamber pressure prevails can be enlarged, thereby improving the sealing separation of the at least one first injection opening from the high-pressure chamber. In one embodiment, the transitions between the at least one first injection opening and the side wall of the nozzle chamber are rounded. Alternatively or additionally, the transitions between the at least one second injection opening and the side wall of the nozzle chamber 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. The trough-shaped nozzle body groove makes it easier to round the transitions between the at least one first injection opening and the side wall of the nozzle chamber. Rounding 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 extending from the nozzle chamber and a second opening section adjoining the first opening section, wherein the diameter of the second opening section is greater than the diameter of the first opening section. Alternatively or additionally, the at least one second injection opening may have a first opening section extending from the nozzle chamber and a second opening section adjoining the first opening section, wherein the diameter of the second opening section is greater 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 makes it possible to achieve improved atomization of fuel for injection, 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 widening profile thanks to the second opening section. Due to this profile, the most advantageous ratio of hole diameter to 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 section can have at least partially a cylindrical or conical profile.In the case of 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 embodiment, a cover with a central recess for the at least one first and the at least one second injection openings is fastened 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, wherein the nozzle body has two bores which are designed to supply and discharge cooling liquid into the intermediate space. In one embodiment, the fuel injection valve further comprises an intermediate part which, together with the guide part and the control piston, defines 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 stem 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 cooperating with the head, wherein 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 actuated actuator arrangement for connecting the valve chamber to and separating the valve chamber 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 single 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, for example 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 open, on the side facing away from the control chamber, into a blind hole cut out on the intermediate valve member and belonging to the valve chamber. The throttle passage is preferably formed in the intermediate valve member adjacent to the control chamber. The throttle passage and the blind hole are preferably formed centrally to the longitudinal axis. This allows the throttle passage to be formed with the desired length and, on the other hand, the blind hole to form part of the valve chamber. List of characters Embodiments of the invention are explained in more detail with reference to the following figures and the associated description. They show schematically: Fig. 1 shows a longitudinal section through a fuel injector from the prior art; Fig. 2 shows a detail of an embodiment of a fuel injector in a longitudinal section; Fig. 3a shows a detail of a further embodiment of a fuel injector in a longitudinal section; Fig. 3b shows an enlarged view of the area of the embodiment of the fuel injector circled therein with A; Fig. 4a shows a detail of a further embodiment of a fuel injector in a longitudinal section; Fig. 4b shows an enlarged view of the area of the embodiment of the fuel injector circled therein with B; Fig.5a shows a section of a further embodiment of a fuel injector in a longitudinal section; Fig. 5b shows, enlarged compared to Fig. 5a, the region of the embodiment of the fuel injector encircled therein by a circle designated C; Fig. 6 shows a section of a further embodiment of a fuel injector in a longitudinal section; Fig. 7a shows a section of a further embodiment of a fuel injector in a longitudinal section; Fig. 7b shows a downstream region of the embodiment of the fuel injector, enlarged compared to Fig. 7a. Description of exemplary embodiments In the description of the figures, the same reference numerals are used for corresponding parts of the embodiments. Fig. 1 shows a representation of a fuel injector 10' from the prior art, exemplified according to WO2016 / 041739 A1, for the intermittent injection of fuel into a combustion chamber of an internal combustion engine. The fuel injector 10' has a housing 12' defining 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 arranged between the housing body 14' and the nozzle body 16'. 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', lie against each other at the end, are pressed against each other in a sealing manner by means of the union nut 22' and are aligned with each other 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 a high-pressure chamber 26' extends 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'. 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 disc-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 hindrance, but prevents fuel from flowing out of the high-pressure chamber 26' into the high-pressure feed line, except through the bypass. The structure and operation of the cartridge-shaped unit with the valve carrier 28', the check valve 30', and the perforated filter 32' are disclosed in document WO2014 / 131497 A1. The high-pressure fuel inlet 24' and the valve carrier 28' with check valve 30' and perforated filter 32' can also be configured 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 perforated filter 32', is known from document WO2009 / 033304 A1. The corresponding disclosures of the above-mentioned documents are incorporated into the present disclosure by reference. Adjacent to the valve carrier 28', the high-pressure chamber 26' has a discrete storage 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 operation 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 incorporated by reference into the present disclosure. Instead of the check valve 30', in certain embodiments a stationary immovable throttle may also be provided. An electrically actuated actuator assembly 38' is accommodated in a recess of the actuator receiving body 20'. With its tappet 40', which is spring-loaded in one direction and movable in the other direction by an electromagnet of the actuator assembly 38', the actuator assembly 38' is designed to close a low-pressure outlet in order to separate a valve chamber from a low-pressure fuel return (see Fig. 2), and to open the low-pressure outlet in order to connect the valve chamber and the low-pressure fuel return. The longitudinal axis of the tappet 40', designated 48', and thus of the actuator assembly 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 injection valve 10', a channel 33' runs from an electrical connection 31' through the housing body 14' to the actuator arrangement 38', in which channel the electrical control line for controlling the actuator arrangement 38' is accommodated. The plunger 40' extends through the bottom of the cup-shaped actuator receiving body 20', which forms a guide element for the plunger 40'. The plunger 40' has radially projecting guide vanes, with which it is slidably guided on the guide element parallel to the longitudinal direction L. The guide vanes form passages extending in the longitudinal direction L, through which the fuel can flow from the low-pressure outlet to the low-pressure fuel return. Viewed in the direction of flow of the fuel downstream of the injection valve seat 18', injection openings are formed in a hemispherical free end region of the nozzle body 16' in a known manner, through which, when the injection valve member 56' is lifted from the injection valve seat 18', the fuel under very high pressure is injected into the combustion chamber of the internal combustion engine. 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 bore in the nozzle body 16' that is concentric with the longitudinal axis L and belongs to the high-pressure chamber 26'. Recesses on the injection valve member 56' that extend in the longitudinal direction and are open outward in the radial direction enable the low-loss flow of fuel to the injection valve seat 18' and to the injection openings. Fig. 2 shows a section of an embodiment of a fuel injector 10.1 in a longitudinal section, wherein the section corresponds to the area of the rectangle designated II in Fig. 1. The concrete design of this area differs from the fuel injector 10' shown in Fig. 1 and is described below with reference to Fig. 2. For example, the actuator arrangement 38 is arranged in a mirror image on the longitudinal axis L compared to the actuator arrangement 38' of Fig. 1. The flow channel 36 is also arranged on the opposite side of the longitudinal axis L compared to the flow channel 36' of Fig. 1. The remaining area outside the area shown in Fig. 2 essentially corresponds to the fuel injector 10' shown in Fig. 1 (i.e. outside area II). This also applies accordingly to the sections of the other embodiments of fuel injectors shown in Figs. 3-6. As in Fig. 1, an electrically operated actuator assembly 38 is accommodated in a recess of the actuator receiving body 20. The actuator assembly 38, with its tappet 40, which is spring-loaded in one direction and movable in the other direction by means of an electromagnet of the actuator assembly 38, is designed to close a low-pressure outlet 42 in order to separate a valve chamber 44 from a low-pressure fuel return 46, and to open the low-pressure outlet 42 in order to connect the valve chamber 44 and the low-pressure fuel return 46. The longitudinal axis of the tappet 40, designated 48, and thus of the actuator assembly 38, runs parallel and eccentrically to the longitudinal axis L. The tappet 40 has guide vanes projecting in the radial direction, with which it is slidably guided parallel to the longitudinal direction L.The guide vanes form passages extending 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 each other in a sealing manner. An injection valve member 56 is arranged in the housing 12 and is adjustable in the direction of the longitudinal axis L. The injection valve member has a shoulder 55 against which a compression spring 63 rests at one end. The other end of the compression spring 63 rests on the end face of 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. A control piston 68 arranged at an upstream end of the injection valve member 56 is guided displaceably along the longitudinal axis L in the guide part 64 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 delimit a control chamber 70 from the high-pressure chamber 26. 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 incorporated by reference into the present disclosure. A circular-cylindrical guide recess extends through the intermediate part 66 from the flat end facing the control chamber 70 to the likewise flat end facing away from the control chamber 70. A shaft 76 of a mushroom-shaped intermediate valve member 78 is guided in this guide recess. A head 80 of the intermediate valve member 78, which is integrally formed with the shaft 76, is located in the control chamber 70 and, with its side facing the intermediate part 66, interacts with the intermediate part 66, the flat end of which forms an annular intermediate valve seat. A throttle passage 90 is formed on the head 80 and runs from the end of the head 80 facing the control piston 68 to a blind bore in the intermediate valve member 78. The intermediate valve member 78, together with the intermediate valve seat formed on the intermediate part 66, forms an intermediate valve 83 of the hydraulic control device 72. For the design of the intermediate valve 83, reference is made, for example, to WO2021 / 165275 A1 or WO2020 / 260285 A1, the corresponding disclosures of which are incorporated into the present disclosure by reference. The nozzle body 16 has a nozzle chamber 165 connected to the high-pressure chamber 26, as well as a first injection valve seat 163 and a second injection valve seat 164. The nozzle body 16 further has a plurality of first injection openings 161 extending from the nozzle chamber 165 and a plurality of second injection openings 162 extending 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 diameter of the second injection openings 162 and can be used for a pilot injection or, when operating with gas as the main fuel, for a pilot injection. The compression spring 63 applies a closing force to the injection valve member 56, acting in the direction of the first injection valve seat 163. The injection valve member 56 comprises a main needle 57, with the control piston 68 arranged at an end of the main needle 57 facing away from the first injection valve seat 163, a needle sleeve 58 arranged at an end of the main needle 57 facing the first injection valve seat 163, and a needle pin 59 arranged partially in the needle sleeve 58. The needle pin 59 is guided in the needle sleeve 58 along the longitudinal axis L and is adjustable relative to the main needle 57. The needle sleeve 58 has a first valve sealing surface 581, which is designed to sealingly cooperate 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 sealingly cooperate with the second injection valve seat 164 for connecting and separating the first injection openings 161 to and from the high-pressure chamber 26. A needle control chamber 51 is arranged between the needle pin 59 and the main needle 58, which 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, with 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 fastened via a press fit. A retaining spring 52 is arranged in the needle control chamber 51 and applies a holding force to the needle pin 59 directed toward the second injection valve seat 164.The needle pin 59 has a guide section 592, which is guided with a sliding fit in a lower guide passage of the needle sleeve 58. Upstream of the guide section 592, the needle pin 59 has a collar section 593, which is received in an upper guide passage of the needle sleeve 58. There is greater clearance between the collar section 593 and the needle sleeve 58 than between the guide section 592 and the needle sleeve 58. The injection valve member 56 is designed, in a closed position shown in Fig. 2, to separate the first injection openings 161 with the needle sleeve 58 through the 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 the sealing interaction of the second valve sealing surface 591 with the second injection valve seat 164 from the high-pressure chamber 26. By lifting 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 presses against the second injection valve seat 164 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 the engagement 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 exposed 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 adjusting the main needle 57 and the injection valve member 56 along the longitudinal axis L, wherein the movement of the injection valve member 56 is controlled in a precise and reliable manner by the hydraulic control device 72 with the intermediate valve 83.Accordingly, by adjusting the injection valve member 56 along the longitudinal axis L, the first injection openings 161 for a pilot or ignition jet injection or the first and second injection openings 161, 162 for a main injection of liquid fuel from the high-pressure chamber 26 into the combustion chamber of the internal combustion engine can be opened. Fig. 3a shows a detail of a further embodiment of a fuel injector 10.2 in a longitudinal section, wherein only the lower region of the fuel injector 10.2 is shown. The remaining, upper region can be designed according to the embodiment shown in Fig. 2. 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 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 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 locally reduced. Furthermore, Fig. 3a shows that the first injection openings 161 each have a first opening section 161.1 extending 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 larger than the diameter of the first opening section 161.1, both in terms of its maximum and its average diameter. The second injection openings 162 extend from a part 166 of the nozzle chamber 165, which is arranged below or downstream of the second injection valve seat 164. For the needle pin 59, it is therefore sufficient to simply or partially contact the second injection valve seat 164 with the second valve sealing surface 591 in the closed position and in the intermediate position.with a linear seal or a radially circumferential sealing surface of small width in order to separate the second injection openings 162 from the high-pressure chamber 26. The first injection openings 161, however, extend 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 inward and radially outward, ie twice or with a surface seal, also radially inward and outward. 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. Adjacent to the guide section 592, upstream, is a collar section 593 with a larger radial diameter than the guide section 592. The collar section is received in an upper guide passage 582.2, with greater clearance 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 is formed at the transition between the lower guide passage 582.1 and the upper guide passage 582.2. 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 engage with one another such 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 release 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 apply a holding force to the needle pin 59 directed against the second injection valve seat 164 when the open position of the injection valve member 56 is reached again. The needle pin 59 protrudes with the second valve sealing surface 591 from the end of the needle sleeve 58 facing the first injection valve seat 163. Therefore, when the injection valve member 56 moves from the open position to the closed position, the needle pin 59 with the second valve sealing surface 591 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. 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, with the second injection valve seat 164 adjoining the first injection valve seat 163 downstream. In the embodiment shown in Fig. 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 the fuel injector 10.2 circled in Fig. 3a with a circle designated A. An outer radially circumferential collar 587 is formed between the outer radially circumferential 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 end surface 585 formed on the outer radially circumferential recess 584, which has an inclination opposite to the first injection valve seat 163. Due to the recess 584 and the collar 587, elasticity of the needle sleeve 58 is provided in the region 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 particularly in the region of the outer valve sealing surface 581.2. The needle sleeve 58 has a radially circumferential, trough-shaped groove 5810 at the end facing the first injection valve seat 163, which is adjacent to 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, the trough-shaped groove 5810 is connected to the first injection openings 161 during the sealing interaction of the first valve sealing surface 581 with the first injection valve seat 163 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 encircling recess 583 provides a sufficient distance between the needle pin 59 and the needle sleeve 58 in the region of the inner radially encircling recess 583, so that during the transition from the closed position to the intermediate position, an undesirable lifting of the needle pin 59 when lifting the needle sleeve 58 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 can be reduced or avoided. Fig. 4a shows a detail of another embodiment of a fuel injector 10.3 in a longitudinal section. As with the fuel injector 10.2 shown in Fig. 3a and Fig. 3b, the needle sleeve 58 of the fuel injector 10.3 has an outer radially circumferential recess 584 on a radially outer side surface adjacent to the first valve sealing surface 581. Furthermore, the needle sleeve 58 also has an inner radially circumferential recess 583, which, however, is more pronounced than the inner radially circumferential recess of the fuel injector 10.2 in Figs. 3a-b and is described further in Fig. 4b. Fig. 4a also shows a retaining knob 595 of the needle pin 59, which serves to hold the retaining spring 52. As already described for the fuel injector 10.2 in Fig. 3a-b, the needle pin 59 has a needle shoulder 594 at the transition between the collar section 593 and the guide section, which is designed to interact with a 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 defines the stroke of the needle sleeve 58 for the movement from the closed position to the intermediate position with the needle pin 59 in a fixed position, in which the at least one second injection opening is separated from the high-pressure chamber. The distance or stroke H is between 0.1 and 0.2 mm. Fig. 4b shows the area of the embodiment of the fuel injector 10.3 circled in Fig. 4a with a circle designated B. An inner radially circumferential collar 589 is formed between the inner radially circumferential 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 closing 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, i.e. 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 encircling collar 587 is delimited on a side facing away from the first valve sealing surface 581 by the outer conical end surface 585 formed by the outer radially encircling recess 584, which has an inclination 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 circumferential recess 583 and the inner radially circumferential collar 589, in addition to the elasticity of the needle sleeve 58 in the region of the outer valve sealing surface 581.2, elasticity of the needle sleeve 58 is provided in the region of the inner valve sealing surface 581.1 due to the outer radially circumferential recess 584 and the outer radially circumferential collar 587. In addition, as in the fuel injection valve 10.2 of Fig. 3a-b, a sufficient distance is provided by the inner radially circumferential recess 583 between the needle pin 59 and the needle sleeve 58 in the region of the inner radially circumferential recess 583, so that during the transition from the closed position to the intermediate position, an undesired lifting of the needle pin 59 when lifting the needle sleeve 58 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. The needle sleeve 58 has, at the end facing the first injection valve seat 163, a radially circumferential, trough-shaped groove 5810, to which the inner valve sealing surface 581.1 and the outer valve sealing surface 581.2 adjoin and which, in the closed position of the intermediate valve member, is connected to the first injection openings 161. Fig. 5a shows a detail of another embodiment of a fuel injector 10.4 in a longitudinal section. Compared to the fuel injectors 10.1-10.3 shown in Figs. 2-4b, the injector member 56 has a main needle 57 with a knob-shaped end facing the first injector seat 163. The knob-shaped end of the main needle 57 has an upper knob 573 and a lower knob 574 with a smaller radial diameter, adjacent to the upper knob 573 downstream. The needle sleeve 58 is fastened to the upper knob 573 of the main needle 57 via a press fit. The lower knob 574 serves to hold the retaining spring 52 at its upstream end. At its downstream end, the retaining spring is held radially by a retaining knob 595 of the needle pin 59. The control chamber 51 is axially delimited by the main needle 57 and the needle pin 59. The control chamber 51 is radially delimited by the needle sleeve 58, in whose side wall a transverse bore 5811 is arranged, which connects the control chamber 51 with the high-pressure chamber 26 or with the nozzle chamber 165. The needle pin 59 again has a guide section 592, which is guided with a sliding fit in a lower guide passage of the needle sleeve 58, and a collar section 593, which is received in an upper guide passage of the needle sleeve 58. Fig. 5b shows the area of the embodiment of the fuel injector 10.4 circled in Fig. 5a with a circle labeled C. The first injector seat 163 is conical with an opening angle that is the same as the opening angle of the conical second injector seat 164, with the second injector seat 164 adjoining the first injector seat 163 downstream. Compared to the fuel injectors 10.1-10.3 shown in Figs. 2-4b, the first opening angle of the first injector seat 163 and the second opening angle of the 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, in the closed position of the injection valve member, two annular sealing surfaces form between the first injection valve seat 163 and the first valve sealing surface 581, which are arranged radially inward on the one hand and radially outward on the other with respect to the first injection openings 161. As with 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 a widening profile. The second injection openings 162 are arranged below the second injection valve seat 164. 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. In the embodiment according to Fig. 5a and Fig. 5b, the inner and outer recesses of the needle sleeve are also provided in accordance with the arrangement shown in Fig.4a and Fig. 4b shown recesses 583 and / or 584 are possible. Fig. 6 shows a section of another embodiment of a fuel injector 10.5 in a longitudinal section. A cover 29 with a central recess for the first and second injection openings 161, 162 is attached to a lower or downstream end of the nozzle body 16. A radially encircling, toroidal intermediate space 291 is formed between the cover 29 and the nozzle body 16. The nozzle body 16 has two bores 37, which are designed to supply and discharge cooling fluid into the intermediate space 291. The fuel injector 10.5 has two flow channels 36.1 and 36.2 of the high-pressure chamber 26. The tappet 40 of the electrically actuated actuator arrangement 38 and the low-pressure outlet 42 are arranged centered to 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, formed integrally with the shaft 76, is located in the control chamber 70 and, with its side facing the intermediate part 66, interacts with the intermediate part 66, the flat end face of which forms an annular intermediate valve seat. A high-pressure fuel inlet 86 extends in the intermediate part 66, which is connected to the high-pressure chamber 26 and comprises a horizontal bore and a vertical bore.In the closed position of the intermediate valve member 78, the vertical bore opens into a gap annular 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 bore 92 can be flooded with fuel. The inlet (not shown in Fig. 6 ) opens with a first end into a blind bore 92 which runs through the shaft 76 and 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 shaft 76 connects to the head 80.A throttle passage 90 is formed on the head 80, which extends from the end face of the head 80 facing the control piston 68 to the blind bore 92 and connects the valve chamber 44 to the control chamber 70. In the closed position of the intermediate valve member 78, 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 longitudinal section of a further embodiment of a fuel injector 10.6. The fuel injector 10.6 comprises 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 comprises a needle sleeve 58, which is arranged at a downstream end of the main needle 57, and a needle pin 59 arranged partially in the needle sleeve 58. The needle pin 59 has a fastening shaft 596, which is fastened via a press fit in a sleeve-shaped end 572 of the main needle 57 and is therefore arranged stationary relative to the main needle 57. In the axial direction, a washer 576 is arranged in the sleeve-shaped end 572 between the fastening shaft 596 of the needle pin 59 and the main needle 57. A bore 575 is arranged upstream of the washer 576. The needle sleeve 58 is arranged at the downstream end of the main needle 57, wherein the needle sleeve 58 is arranged adjustable relative to the main needle 57 and the needle pin 59 fastened to the main needle 57.A retaining spring 52 is arranged between the main needle 57 and the needle sleeve 58, which applies a holding force in the downstream direction to the needle sleeve 58 in the open position of the injection valve member 56. The hydraulic control device for controlling the movement of the injection valve member 56 along the longitudinal axis L essentially corresponds to that of the embodiment of the fuel injection valve 10.5 shown in Fig. 6. The fuel injector 10.6 has first injection openings 161 and second injection openings 162, wherein the first injection openings 161 have a larger minimum diameter than the minimum diameter of the 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 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 a sealing interaction with the needle pin 59. Fig. 7b shows a downstream region of the embodiment of the fuel injector 10.6, enlarged 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 to connect and separate the first injection openings 161 to and from the high-pressure chamber 26 and the nozzle chamber 165, respectively. With respect to the first valve sealing surface 581, the 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 the fuel injector 10.3 shown in Fig. 4a and Fig. 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 sealingly interacts with the second injection valve seat 164 of the nozzle body 16 to connect and disconnect the second injection openings 162 to and from the high-pressure chamber 26 and the nozzle chamber 165, respectively. The second injection openings 162 extend from a portion 166 of the nozzle chamber 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 extend from the second injection valve seat 164 (comparable to the first injection openings 161, which extend from the first injection valve seat 163), particularly when the portion 166 has a small volume. 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, an intermediate space 168 is arranged, which 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 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 with multiple steps that tapers towards the second valve sealing surface 591. A first step 597 creates a region of the gap 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 section 592 is a collar section 593 that has a smaller radial diameter than the guide section 592. The collar section 593 projects through an upper guide passage 582.2, which is formed by an axial bore in 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 is arranged in the bottom of the cup-shaped needle sleeve 58, so that the needle pin 59 with its collar section 593 protrudes through the bottom of the cup-shaped needle sleeve 58. The retaining spring 52 is held radially at its upstream end by the sleeve-shaped end 572 of the main needle 57 and radially at its downstream end by a holding region 5812 of the needle sleeve 58 with a reduced radial diameter. The needle sleeve 58 is guided on the needle pin 59 so as to be adjustable in the axial direction relative to the main needle 57, with the retaining spring 52 applying a holding force to the needle sleeve 58 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 defines the stroke of the needle pin 59 for the movement from the closed position to the intermediate position with the needle sleeve 58 in a fixed position, in which the first injection openings 161 are separated from the high-pressure chamber 26. 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 designed, in a closed position shown in Fig. 7b, to separate the first injection openings 161 with the needle sleeve 58 through the 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 the sealing interaction of the second valve sealing surface 591 with the second injection valve seat 164 from the high-pressure chamber 26. By lifting the needle pin 59 from the second injection valve seat 164, the intermediate position can be reached in which the second injection openings 162 are released and connected to the high-pressure chamber 26, while the needle sleeve 58 remains in the position in which the needle sleeve 58 presses against the first injection valve seat 163 and the first injection openings 161 are thereby separated from the high-pressure chamber 26.By further lifting the needle pin 59, the needle sleeve 58 is also raised due to the engagement 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 exposed and 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 openings 162 for a pilot or ignition jet injection or the first and second injection openings 161, 162 for a main injection of liquid fuel from the high-pressure chamber 26 into the combustion chamber of the internal combustion engine can be opened. QUOTES CONTAINED IN THE DESCRIPTION This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature US 2007 / 0246561 A1

[0004] WO 2016 / 041739 A1

[0122] WO 2014 / 131497 A1

[0125] WO 2013 / 117311 A1

[0125] WO 2009 / 033304 A1

[0125] WO 2007 / 009279 A1

[0127] WO 2021 / 165275 A1 [0138, 0140, 0166]WO 2020 / 260285 A1 [0138, 0140]

Claims

A fuel injection valve (10.1-10.6) for the intermittent injection of fuel into the combustion chamber of an internal combustion engine, comprising a housing (12) defining a longitudinal axis (L) and having a high-pressure fuel inlet and a nozzle body (16) with a nozzle chamber (165) and a first and a second injection valve seat (163, 164), wherein the nozzle body (16) has at least one first injection opening (161) extending from the nozzle chamber (165) and at least one second injection opening (162) extending from the nozzle chamber (165) for injecting fuel into the combustion chamber of the internal combustion engine, a high-pressure chamber (26) arranged in the housing (12) and extending from the high-pressure fuel inlet to the nozzle chamber (165), an injection valve member (56) arranged in the housing (12) such that it can be adjusted in the direction of the longitudinal axis (L), a compression spring (63),which applies a closing force to the injection valve member (56) directed toward 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) arranged at an end of the main needle facing away from the first injection valve seat (163) and guided in a sliding fit in a guide part (64), a needle sleeve (58) arranged at an end of the main needle (57) facing the first injection valve seat (163), and a needle pin (59) arranged at least partially in the needle sleeve (58), wherein the needle sleeve (58) has a first valve sealing surface (581) which is formed,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), wherein 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 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) have different minimum diameters. Fuel injection valve (10.1-10.6) according to claim 1 or 2, characterized in that the at least one second injection opening (162) is arranged downstream of the at least one first injection opening (161). Fuel injection valve (10.1-10.5) according to one of the preceding claims, characterized in that the needle sleeve (58) is fastened to the main needle (57) and the needle pin (59) is guided in the needle sleeve (58) along the longitudinal axis (L) and adjustably relative to the main needle (57). 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 opening (162). Fuel injection valve (10.1-10.5) according to claim 4 or 5, characterized in that the injection valve member (56) is designed to, in a closed position, separate 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) to the high-pressure chamber (26) by lifting the needle sleeve (58) from the first injection valve seat (163) and to separate the at least one second injection opening (162) with the needle pin (59) from the high-pressure chamber (26); in an open position, to separate 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) to connect to the high pressure chamber (26). Fuel injection valve (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 with the needle pin (59) in a fixed position, the stroke (H) preferably being between 0.1 and 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), wherein the sleeve shoulder (586) and the needle shoulder (594) can engage with one another between the intermediate position and the open position in such a way that the needle pin (59) can be lifted from the second injection valve seat (164) by the needle sleeve (58). Fuel injection valve (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), wherein there is a greater radial play between the collar section (593) and the needle sleeve (58) 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 a needle control chamber (51) is arranged between the needle pin (59) and the main needle (57), which is connected to the high-pressure chamber (26) and axially delimited by the needle pin (59) and the main needle (57). 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), wherein a radial side wall (572) of the recess at least partially radially delimits 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 radially delimited 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). Fuel injection valve (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), which spring acts on the needle pin (59) with a holding force directed towards the second injection valve seat (164). Fuel injection valve (10.1-10.5) according to claim 8 and 13, characterized in that the retaining spring (52) presses the needle shoulder (594) of the needle pin (59) against the sleeve shoulder (586) of the needle sleeve (58) in the open position. Fuel injection valve (10.1-10.5) according to one of claims 4 to 14, characterized in that the needle sleeve (58) is fastened to the end of the main needle (57) facing the first injection valve seat (163), which end is sleeve-shaped or knob-shaped, preferably via a press fit. Fuel injection valve according to one of claims 4 to 14, characterized in that the needle sleeve is fastened to the end of the main needle facing the first injection valve seat, which end is sleeve-shaped or knob-shaped, by laser welding, via a thread or by brazing. Fuel injection valve according to one of claims 4 to 14, characterized in that the needle sleeve is formed integrally 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 fastened to the main needle (57) and the needle sleeve (58) is guided on the needle pin (59) along the longitudinal axis (L) and adjustably 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) has a smaller minimum diameter than the minimum diameter of the at least one first injection opening (161). Fuel injection valve (10.6) according to claim 18 or 19, characterized in that the injection valve member (56) is designed to, in a closed position, separate 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 second injection opening (162) to the high-pressure chamber (26) by lifting the needle pin (59) from the second injection valve seat (164) and to separate the at least one first injection opening (161) with the needle sleeve (58) from the high-pressure chamber (26); in an open position, to separate 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) to connect to the high pressure chamber (26). Fuel injection valve (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 with the needle sleeve (58) in a fixed position, the stroke (H) preferably being between 0.1 and 0.2 mm. Fuel injection valve (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), wherein the sleeve shoulder (586) and the needle shoulder (594) can engage with one another between the intermediate position and the open position in such a way that the needle sleeve (58) can be lifted from the first injection valve seat (163) by the needle pin (59). Fuel injection valve (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), wherein there is a greater radial play between the collar section (593) and the needle sleeve (58) 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). 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 spring acts on the needle sleeve (58) with a holding force directed towards the first injection valve seat (163). Fuel injection valve (10.6) according to claim 24, characterized in that the retaining spring (52) in the open position presses the sleeve shoulder (586) of the needle sleeve (58) against the needle shoulder (594) of the needle pin (59). Fuel injection valve (10.6) according to one of claims 18 to 25, characterized in that the needle pin (59) is fastened to the end of the main needle (57) facing the first injection valve seat (163), which end is sleeve-shaped or knob-shaped, preferably via a press fit. Fuel injection valve according to one of claims 18 to 25, characterized in that the needle pin is fastened to the end of the main needle facing the first injection valve seat, which end is sleeve-shaped or knob-shaped, by laser welding, via a thread or by brazing. 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) in a region adjoining the second injection valve seat (164) an intermediate space (168) is formed, which is connected to the high-pressure space (26), preferably via a transverse bore (5813) in the needle sleeve (58). Fuel injection valve (10.6) according to claim 28, characterized in that the needle pin (59) has a profile tapering towards the second valve sealing surface (591), wherein the tapering profile preferably has 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 away from the longitudinal axis (L) than the at least one second injection opening (162). Fuel injection valve (10.1-10.3, 10.5, 10.6) according to one of the preceding claims, 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), wherein the first opening angle is 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 second opening angles being the same. Fuel injection valve (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 circumferential collar (587) is formed between the outer radially circumferential recess (584) and the first valve sealing surface (581). Fuel injection valve (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). Fuel injection valve (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 injection valve (10.3, 10.6) according to claim 36, characterized in that an inner radially circumferential collar (589) is formed between the inner radially circumferential recess (583) and the first valve sealing surface (581). Fuel injection valve (10.3, 10.6) according to claim 36 or 37, characterized in that the inner radially circumferential recess (583) forms an inner conical end surface (588) of the radially inner side surface, which is arranged facing away from the first valve sealing surface (581). Fuel injection valve (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) has a radially circumferential, trough-shaped groove (5810) at an end facing the first injection valve seat (163), the inner and outer valve sealing surfaces (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 such that when the first valve sealing surface (581) sealingly 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 circumferential 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 (161.1) extending from the nozzle chamber (165) and a second opening section (161.2) adjoining the first opening section (161.1), wherein the diameter of the second opening section (161.2) is 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 fastened to a lower end of the nozzle body (16) in such a way that a radially circumferential intermediate space (291) is formed between the cover (29) and the nozzle body (16), wherein the nozzle body (16) has two bores (37) which are designed to supply and discharge cooling liquid into the intermediate space (291). Fuel injection valve (10.1-10.6) according to one of the preceding claims, characterized in that the fuel injection valve further comprises: an intermediate part (66) which, together with the guide part (64) and the control piston (68), delimits a control chamber (70), wherein 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), wherein the hydraulic control device (72) comprises an intermediate valve (83) with a mushroom-shaped intermediate valve member (78), which has a shaft (76) guided in a guide recess of the intermediate part (66) and a head (80), and with an intermediate valve seat formed on a side of the intermediate part (66) facing the head (80) and cooperating with the head (80),wherein the intermediate valve member (78) in an open position of 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) 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) - except for a throttle passage (90), an electrically actuated actuator arrangement (38) for connecting the valve chamber (44) to and separating the valve chamber (44) from a low-pressure fuel return (46),wherein the intermediate valve member (78) releases a second connection between the high-pressure fuel inlet (86) and the valve chamber (44) in the open position of the intermediate valve member (78) and interrupts the second connection between the high-pressure fuel inlet (86) and the valve chamber (44) in the closed position of the intermediate valve member (78).

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