FUEL INJECTION VALVE FOR COMBUSTION ENGINES

Description

Field of the invention

[0001] 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

[0002] 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., which necessitates an extension of conventional injection systems.

[0003] 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.

[0004] EP 2546508 A1 discloses a fuel injector having first and second injection openings arranged at different heights with respect to a longitudinal axis of the fuel injector, having a hydraulic control device, and having an electrically actuatable actuator arrangement. Description of the invention

[0005] Given the increased requirements of dual-fuel systems, e.g. with regard to the different fuels, liquid and gaseous, or the introduction of the ignition source in gas operation, it is typically desirable to simplify the design of dual-fuel systems while providing reliable controllability of the injection processes.

[0006] It is therefore an object of the present invention to provide a fuel injection valve, in particular for a dual-fuel system, which at least partially improves the prior art.

[0007] 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.

[0008] 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 and having a high-pressure fuel inlet, an injector seat, and a nozzle body. A high-pressure chamber is arranged in the housing, extending from the high-pressure fuel inlet to the injector seat. Furthermore, an injector member with a valve sealing surface adjustable in the direction of the longitudinal axis is arranged in the housing. The fuel injector further comprises a compression spring, which applies a closing force to the injector member directed toward the injector seat. The compression spring is preferably supported on the one hand on the injector member and on the other hand is fixedly supported relative to the housing.

[0009] The fuel injector further comprises a hydraulic control device for controlling the movement of the injection valve member along the longitudinal axis. The injection valve member has a needle arranged downstream of the valve sealing surface, which extends into a nozzle chamber arranged downstream of the injection valve seat. The valve sealing surface is designed to sealingly cooperate with the injection valve seat to connect the nozzle chamber to the high-pressure chamber and to separate the nozzle chamber from the high-pressure chamber.

[0010] 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, wherein the at least one first injection opening and the at least one second injection opening are arranged at different heights relative to the longitudinal axis. The needle is designed to cooperate with a side wall of the nozzle chamber to close and open the at least one first injection opening and / or the at least one second injection opening (or to cooperate to close and open at least one of the at least one first injection opening and the at least one second injection opening).

[0011] The fuel injection valve preferably further comprises a guide part, in which a control piston of the injection valve member is guided with a sliding fit; 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;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. The intermediate valve member, in an open position, releases a connection between a high-pressure fuel inlet connected to the high-pressure chamber and the control chamber, and, in a closed position, interrupts the 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 line.

[0012] In the open position, the intermediate valve member can release a second or further connection between the high-pressure fuel inlet and the valve chamber and in the closed position can interrupt the second or further connection between the high-pressure fuel inlet and the valve chamber.

[0013] The mushroom-shaped intermediate valve element allows for both precise control of the opening movement of the injection valve element and rapid closing of the injection valve element. Furthermore, multiple injections with very short time intervals can be realized.

[0014] Because the needle projecting into the nozzle chamber interacts with the side wall of the nozzle chamber to close and open the at least one first injection opening and / or the at least one second injection opening, 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. Since the at least one first injection opening and the at least one second injection opening are also arranged at different heights with respect to the longitudinal axis of the housing, the at least one first injection opening and the at least one second injection opening can be selectively closed or opened by controlling and adjusting the injection valve member or the needle along the longitudinal axis of the housing. The control and adjustment of the injection valve member can be achieved precisely and reliably by the hydraulic control device.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., with the same injection valve member using the at least one first injection opening and the at least one second injection opening.

[0015] In connection with the present invention, the person skilled in the art is aware that "closing" the at least one first injection opening and / or the at least one second injection opening does not necessarily have to mean "sealing," but rather covering or covering the at least one first injection opening and / or the at least one second injection opening may be sufficient. Therefore, even with a closed at least one first and / or at least one second injection opening, a small (tolerable) leakage (compared to the injection quantity through an open injection opening) can occur via a gap between the needle and the inner side wall of the nozzle chamber.

[0016] Preferably, when the at least one first injection opening and the at least one second injection opening are closed, the nozzle chamber is separated from the high-pressure chamber by the valve sealing surface of the injection valve member sealingly contacting the injection valve seat. Although the nozzle chamber is fluidically connected to the high-pressure chamber when the injection valve member is lifted from the injection valve seat, a suitable arrangement (i.e. at a suitable height along the longitudinal axis of the housing) of the at least one first injection opening and / or the at least one second injection opening in the side wall of the nozzle chamber can ensure that the at least one first injection opening and / or the at least one second injection opening remains closed until the injection valve member orthe needle is raised to a height at which the at least one first injection opening and / or the at least one second injection opening is opened and connected to the high-pressure chamber. The injection timing through the at least one first injection opening and / or the at least one second injection opening can therefore be adjusted by the height in the side wall at which the injection openings are arranged and / or the length or stroke of the needle.

[0017] Preferably, the needle can be guided in the nozzle chamber with a sliding fit in the region of the at least one first injection opening and the at least one second injection opening. The sliding fit in the nozzle chamber allows the needle to adequately close the injection openings extending from the side wall of the nozzle chamber for practical purposes.

[0018] Preferably, the fuel injection valve has a plurality, e.g. two, four, six or more, of radially symmetrically arranged first injection openings at a first height and a plurality, e.g. two, four or six, of radially symmetrically arranged second injection openings at a second height.

[0019] In an advantageous embodiment, the at least one first injection opening and the at least one second injection opening have different minimum diameters.

[0020] 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 example, for diesel or heavy fuel oil.

[0021] 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.

[0022] In an advantageous embodiment, the at least one second injection opening is arranged downstream of the at least one first injection opening and has a smaller minimum diameter than the minimum diameter of the at least one first injection opening.

[0023] The at least one second injection opening can thus be used for a pilot jet injection of diesel to ignite a lean (natural) gas / air mixture. Since the at least one second injection opening is arranged downstream of the at least one first injection opening, the at least one second injection opening can be opened by raising the needle of the injection valve member, while the needle continues to keep the at least one first injection opening closed. This configuration of the injection openings therefore makes it possible to selectively open the at least one second injection opening for a pilot jet injection.

[0024] In an advantageous embodiment, the needle is designed to close the at least one first injection opening and the at least one second injection opening in a closed position of the injection valve member, to open the at least one second injection opening and to close the at least one first injection opening in a first open position of the injection valve member, and to open the at least one second injection opening and the at least one first injection opening in a second open position of the injection valve member.

[0025] The fuel injector and needle can therefore provide at least three (closing / opening) configurations, which can be used for different operating modes or operating phases. For example, the first open position can be used for pilot injection if the at least one second injection opening has a smaller minimum diameter than the at least one first injection opening. The second open position, on the other hand, can be used, for example, for diesel or heavy fuel oil operation, in which both the at least one first and the at least one second injection opening are open and the fuel injector can be used as the main injector for diesel or heavy fuel oil as the main fuel.

[0026] The fuel injector can therefore provide a pilot injection in gas operation via, for example, at least one second injection opening.

[0027] However, the invention offers the advantage that the fuel injector can also be used for diesel or heavy fuel oil operation. A pre-injection or pilot injection can then be provided via the at least one second injection port, for example, and the main injection can be provided by opening the at least one first and at least one second injection port.

[0028] In diesel or heavy fuel oil operation, for example, one variant allows at least one second injection port to be opened for a pre-injection and then 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.

[0029] In a further variant, a stepped injection can be carried out in diesel or heavy oil operation. For example, the at least one second injection opening can be opened for a pre-injection and the at least one first injection opening can additionally be opened for a main injection. The temporal course of the stepped injection, in particular the duration of the pre-injection, can be adjusted by varying the distance between the at least one second injection opening and the at least one first injection opening along the longitudinal axis. A short pre-injection can be achieved, for example, by a small distance between the at least one second injection opening and the at least one first injection opening along the longitudinal axis.

[0030] For a particularly short pre-injection, the at least one second injection opening and the at least one first injection opening can be arranged such that, for example, the at least one first injection opening is opened with a larger minimum diameter during the opening process of the at least one second injection opening. This can be achieved, for example, by the height of the at least one second injection opening "overlapping" with the height of the at least one first injection opening along the longitudinal axis. In an "overlapping" arrangement, the at least one first and the at least one second injection openings can be arranged alternately or offset in the horizontal direction of rotation of the nozzle body in order to avoid or reduce disadvantageous weakening of the side wall of the nozzle body.

[0031] 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.

[0032] The closed position also offers the advantage that both the at least one first and the at least one second injection opening are sufficiently closed by a side wall of the needle and therefore advantageously leakage of fuel from the nozzle chamber into the combustion chamber of the internal combustion engine can be minimized or practically eliminated.

[0033] In one embodiment, the needle has an inner bore oriented substantially along the longitudinal axis, which extends from a lower end of the needle and is designed to connect the at least one second injection opening to the high-pressure chamber in the first open position of the injection valve member, and to connect the at least one second injection opening and the at least one first injection opening to the high-pressure chamber in the second open position of the injection valve member.

[0034] In the respective open positions, fuel can pass through the inner bore from the high-pressure chamber into the at least one first and / or the at least one second injection opening and can thus be injected into the combustion chamber of the internal combustion engine. Since the inner bore starts from the lower, i.e. downstream, end of the needle and is therefore laterally delimited by a side wall of the needle, the needle can interact in a simple manner with the side wall of the nozzle chamber to close and open the injection openings by moving along the longitudinal axis. Preferably, the inner bore of the needle is connected to the nozzle chamber so that the inner bore can connect the high-pressure chamber to the injection openings via the nozzle chamber in the respective open positions.

[0035] In one embodiment, the nozzle chamber has an upper nozzle chamber arranged downstream of the high-pressure chamber and a lower nozzle chamber arranged downstream of the upper nozzle chamber, wherein the lower nozzle chamber is connected to the upper nozzle chamber via the inner bore of the needle, wherein the at least one first injection opening and the at least one second injection opening extend from the lower nozzle chamber.

[0036] Preferably, the injection valve seat adjoins the upper nozzle chamber above or upstream of the upper nozzle chamber. Preferably, in the respective open positions, the high-pressure chamber is connected to the upper nozzle chamber, so that the high-pressure fuel can flow via the upper nozzle chamber into the inner bore of the needle and from there via the lower nozzle chamber into the at least one first and / or second injection opening.

[0037] In one embodiment, the inner bore of the needle is connected to the upper nozzle chamber via at least one transverse bore in a side wall of the needle.

[0038] With multiple cross-bores, the cross-bores can be arranged at different heights of the needle. With multiple cross-bores, the total inlet cross-section into the inner bore can be increased. This advantageously compensates for pressure losses caused by the double deflection of the flow through the needle. By arranging the multiple cross-bores at different heights of the needle, weakening of the needle's side wall can be reduced or prevented. In one embodiment, multiple cross-bores of the needle are arranged radially symmetrically. In one embodiment, multiple cross-bores of the needle have mirror symmetry.

[0039] In certain embodiments, one or more of the at least one transverse bores can open at least partially into a bore section of the injection valve part arranged below the injection valve seat and above the upper nozzle chamber, which bore section is connected to the upper nozzle chamber.

[0040] In certain embodiments, one or more of the at least one transverse bores can open partially into the upper nozzle chamber and partially into the bore section of the injection valve part.

[0041] In certain embodiments, one or more of the at least one transverse bores can open into the upper nozzle chamber.

[0042] The opening of one or more of the at least one transverse bore into the upper nozzle chamber and / or the bore section of the injection valve part can change depending on the current stroke of the needle.

[0043] In one embodiment, the needle is guided in a sliding fit in the sub-nozzle chamber.

[0044] For injection openings originating from the lower nozzle chamber, the needle can interact in a quasi-sealing manner with the side wall of the lower nozzle chamber thanks to the sliding fit for closing and opening the injection openings.

[0045] In one embodiment, the diameter of the nozzle chamber decreases at the transition from the upper nozzle chamber to the lower nozzle chamber, preferably via a conical gradation.

[0046] In particular, a lower section of the needle can be guided in the lower nozzle chamber for closing and opening the injection openings, preferably in a sliding fit, and an upper section of the needle can be continued with a play in the upper nozzle chamber.

[0047] In a configuration with at least one transverse bore of the needle, the at least one transverse bore can be arranged in an upper section of the needle such that the at least one transverse bore is located in the upper nozzle chamber and / or in a bore section of the injection valve part connected to the upper nozzle chamber and thus connects the upper nozzle chamber to the inner bore.

[0048] The lower nozzle chamber can therefore primarily serve to provide a quasi-sealing surface between the side wall of the needle and the side wall of the lower nozzle chamber for closing or opening the injection openings and the upper nozzle chamber primarily serves to provide the connection to the high-pressure chamber in an open position, preferably by connecting the high-pressure chamber to an inner bore of the needle.

[0049] In one embodiment, the sub-nozzle chamber has a first section and a second section arranged downstream of the first section with a reduced diameter compared to the first section.

[0050] By dividing the sub-nozzle chamber into several sections with different diameters, further options for the selective closing and opening of the injection openings can be made possible, particularly with a suitable arrangement of injection openings.

[0051] For example, in an advantageous embodiment, the at least one second injection opening extends from the second section of the sub-nozzle chamber.

[0052] Furthermore, the at least one first injection opening preferably extends from the first section of the sub-nozzle chamber.

[0053] Due to the separate arrangement of the at least one second injection opening in the second section and the at least one first injection opening in the first section, the at least one second injection opening and the at least one first injection opening can be better and, in particular, more flexibly spaced from one another, in particular without having to increase the maximum stroke of the needle. With a suitable arrangement of the at least one second injection opening in the second section and the at least one first injection opening in the first section, the required maximum stroke of the needle can also be reduced.

[0054] In one embodiment, the needle has a first needle section which is guided in a sliding fit in the first section of the sub-nozzle chamber and a second needle section adjoining the first needle section which can be guided in a sliding fit in the second section of the sub-nozzle chamber.

[0055] The needle can therefore close the at least one second injection opening through the second needle section and close the at least one first injection opening through the first needle section. By dividing the needle into several needle sections, the needle can advantageously be adapted to the respective injection openings to be closed in the respective sections of the sub-nozzle chamber.

[0056] Preferably, the second needle section is guided in a sliding fit between the closed position and the first open position of the injection valve member in the second section of the sub-nozzle chamber.

[0057] The division of the sub-nozzle chamber into several sections, in particular into a first and second section, and the corresponding division of the needle into several needle sections, in particular into a first and second needle section, each for closing the at least one first injection opening and the at least one second injection opening, offers the advantage, as already described, that the at least one first injection opening and the at least one second injection opening can be better and, in particular, more flexibly spaced from one another. In particular, the at least one first injection opening and the at least one second injection opening can be arranged further apart from one another along the longitudinal axis of the housing without increasing the maximum stroke of the needle.The maximum stroke of the needle advantageously does not need to be increased, since the stepped shape of the sub-nozzle chamber (due to the first and second sections) and the needle (due to the first and second needle sections) eliminates the need for the needle's lower end to be raised above the height of the at least one first injection opening to reach the second open position. Rather, it is advantageously sufficient if the needle is raised above the height of the at least one first injection opening with the step between the first and second needle sections.

[0058] In one embodiment, the first and second needle sections are connected to one another via a conical step.

[0059] The first and second sections of the sub-nozzle chamber can also be connected to each other via a conical step.

[0060] In one embodiment, the first and / or second needle section and / or the first and / or second section of the sub-nozzle chamber can be designed such that, when the needle is raised, the at least one first injection opening is opened before the at least one second injection opening is opened. This can be achieved in particular if the length of the second needle section or the summed length of the second needle section and the conical step is greater than the distance between the at least one second injection opening and the at least one first injection opening along the longitudinal axis. With such a configuration, therefore, for example, a fuel injector can be provided in which a pre-injection or, when operating with gas as the main fuel, an ignition jet injection is carried out through the at least one first injection opening.

[0061] The functionalities of the at least one second injection opening and the at least one first injection opening can therefore be exchanged by suitable geometries of the sub-nozzle chamber or its first and second sections and / or the needle or its first and second needle sections, and further with a suitable adaptation of the minimum diameters of the at least one first and / or the at least one second injection opening.

[0062] In one embodiment, the nozzle chamber is designed in the manner of a blind hole with a bottom, wherein the nozzle chamber in the closed position of the injection valve member has a free space delimited by a lower end of the needle and the bottom of the blind hole-like nozzle chamber.

[0063] With an inner bore of the needle extending from the lower end of the needle, the free space is therefore connected to the inner bore. In an open position of the injection valve member, the free space can increase in size and be at least partially delimited by a lower end of the needle and the bottom of the blind-hole-like nozzle chamber, wherein the fuel can pass from the high-pressure chamber via the inner bore of the needle and via the enlarged free space into the at least one second or at least one first injection opening. In the closed position of the injection valve member, the free space is preferably closed off from the combustion chamber of the internal combustion engine, so that advantageously no significant leakage of fuel into the combustion chamber can occur.

[0064] In one embodiment, the nozzle chamber has an undercut at a downstream end. In particular, the free space may have an undercut.

[0065] In one embodiment, the injection valve seat is formed in an injection valve part, wherein the nozzle body is detachably fastened to the injection valve part, preferably via a union nut.

[0066] The detachable fastening of the nozzle body to the injection valve part offers the advantage of easy replaceability of the nozzle body, since the nozzle body is generally a wearing part due to the wear of the at least one first and / or the at least one second injection opening.

[0067] In one embodiment, the needle has a sleeve, preferably made of steel, which is designed to cooperate with the side wall of the nozzle chamber for closing and opening the at least one first injection opening and / or the at least one second injection opening.

[0068] The sleeve advantageously allows for improved closure of the injection ports. Furthermore, the sleeve advantageously provides protection for the sidewall of the needle and can be easily replaced if necessary.

[0069] Preferably, the sleeve is subjected to a clamping force directed radially against the side wall of the nozzle chamber.

[0070] The clamping force directed radially against the side wall of the nozzle chamber can further improve the closing of the injection openings.

[0071] In one embodiment, the at least one second 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.

[0072] The second opening section preferably opens into the combustion chamber of the internal combustion engine. The stepped shape of the at least one second injection opening allows for improved atomization of fuel for the pilot injection, since the at least one second injection opening has a narrow diameter over a reduced length, namely along the first opening section, and 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 second injection opening can be realized in order to achieve optimal atomization of the ignition jet in the combustion chamber.

[0073] In one embodiment, the at least one first injection opening and / or the at least one second injection opening extends from the nozzle chamber via a trough-shaped recess.

[0074] Preferably, the transitions between the injection openings and the side wall of the nozzle chamber are rounded. In particular, the transitions between the injection openings and the trough-shaped recesses are preferably rounded. The trough-shaped recess makes it easier to round the transitions between the injection openings 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 recess offers the advantage of a more stable flow of fuel through the injection opening over time.

[0075] 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 through a gap between 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.

[0076] The head of the mushroom-shaped intermediate valve member can have a sealing surface extending at a radial distance around the shaft, with which the head - in the closed position of the intermediate valve member - can bear sealingly against an intermediate valve seat formed on the intermediate part, forming an annular sealing surface. The shaft of the mushroom-shaped intermediate valve member can be guided with a tight sliding fit in the guide recess of the intermediate part. On the side facing the shaft and thus the intermediate part, an annular sealing bead can be formed on the head, protruding from the rest of this side of the head, the free end of which can form the sealing surface of the intermediate valve member.

[0077] The intermediate part, the shaft, and the head can define an annular space into which a high-pressure fuel inlet connected to the high-pressure chamber can open. The annular space can have an inner annular space running around the shaft and delimited in the radial direction by the shaft and intermediate part, which can be recessed on the shaft itself, whereby the high-pressure fuel inlet can open into the inner annular space. The valve chamber can be connected to the high-pressure chamber and thus to the high-pressure inlet via a throttle inlet. The annular space can have a gap annular space adjoining the inner annular space. In the closed position of the intermediate valve member, this gap annular space can be formed by a circumferential gap between the intermediate part and the head of the intermediate valve member.

[0078] The inner annular space can be formed on the shaft of the intermediate valve member by a circumferential annular groove that is open radially outward. This groove, viewed along the longitudinal axis, can be dimensioned such that the opening of the high-pressure inlet always lies at least approximately completely within the area of ​​the annular groove. Furthermore, the annular groove can be directly connected to the head.

[0079] With an intermediate valve member that, in the open position, releases a second connection between the high-pressure fuel inlet and the valve chamber, the valve chamber can be filled with fuel via the second connection, enabling a faster opening movement of the intermediate valve member. In particular, the second connection can improve the filling of the valve chamber compared to a fuel injector, in which the filling of the valve chamber occurs, for example, solely from the control chamber via a throttle passage. Advantageously, therefore, the valve chamber can be filled via the second connection even with a small opening movement of the intermediate valve member.As far as the throttle passage is concerned, it is advantageously sufficient if the flow of fuel from the control chamber into the valve chamber through the throttle passage causes the initially small opening movement of the intermediate valve member, since the valve chamber can then be filled with a large quantity of fuel via the second connection.

[0080] Because the intermediate valve member interrupts the second connection between the high-pressure fuel inlet and the valve chamber in the closed position, it is advantageously possible to prevent fuel from flowing from the high-pressure chamber via the second connection into the low-pressure fuel return when the intermediate valve member is in the closed position. By interrupting the second connection between the high-pressure fuel inlet and the valve chamber in the closed position of the intermediate valve member, fuel loss and wear caused by the expansion of the fuel from the high-pressure chamber into the valve chamber during the injection process can be reduced or minimized, while simultaneously achieving rapid filling of the valve chamber for the opening movement of the intermediate valve member.

[0081] In one embodiment, the second connection runs between the high-pressure fuel inlet and a bore extending through the shaft of the intermediate valve member, which bore is part of the valve chamber. Preferably, the bore is designed as a blind hole.

[0082] In one embodiment, in the closed position of the intermediate valve member, the head rests with a side facing the intermediate part via a first sealing surface running at a first radial distance around the shaft or the guide recess to form a first annular sealing surface that is closed in the circumferential direction, and via a second sealing surface running at a second radial distance around the shaft or the guide recess to form a second annular sealing surface that is closed in the circumferential direction, the intermediate valve seat, wherein the first radial distance is greater than the second radial distance.

[0083] In one embodiment, a first annular sealing bead with a first end face, which forms the first sealing surface, is formed on the side of the head facing the intermediate part or the side of the intermediate part facing the head.

[0084] In one embodiment, a second annular sealing bead with a second end face, which forms the second sealing surface, is formed on the side of the head facing the intermediate part or the side of the intermediate part facing the head.

[0085] In one embodiment, the intermediate part has at least one step on the side facing the head and the head has at least one step on the side facing the intermediate part, wherein, in the closed position of the intermediate valve member, edges of the steps of the intermediate part and of the head that are offset from one another each radially delimit the first and / or the second annular sealing surface.

[0086] In one embodiment, a step of the intermediate part forms an inner annular space which is delimited by the intermediate part, the shaft and the head in the closed position of the intermediate valve member.

[0087] In one embodiment, the high-pressure fuel inlet runs in the intermediate part in such a way that the high-pressure fuel inlet opens into a gap annular space in the closed position of the intermediate valve member, which gap annular space is formed between the intermediate part and the head in the closed position of the intermediate valve member and is radially delimited by the first and the second annular sealing surface.

[0088] In one embodiment, the second connection comprises an inlet of the intermediate valve member, which opens into the valve chamber at a first end and opens into an outer side of the intermediate valve member at a second end. As already explained above, the valve chamber can advantageously be filled via the inlet to support the opening movement of the intermediate valve member. Preferably, the inlet opens with its first end into the blind bore, which runs through the shaft and is part of the valve chamber.

[0089] In one embodiment, the inlet opens with the second end to the outside of the intermediate valve member in such a way that the second end is arranged at a radially smaller distance from the shaft than the second annular sealing surface in the closed position of the intermediate valve member.

[0090] In one embodiment, the second connection comprises a passage which is formed by a clearance of at least 10 µm, preferably between 20 µm and 50 µm, in the radial direction between the shaft and the guide recess.

[0091] In one embodiment, the shaft has two annular projections spaced apart from one another in the longitudinal direction of the shaft.

[0092] In one embodiment, the annular projections each have at least one chamfer in the circumferential direction, wherein the second connection comprises a passage which is formed by a space between the at least one chamfer and the guide recess. Due to the at least one chamfer, the play between the shaft and the guide recess can be kept sufficiently small, which allows better centering of the shaft, i.e. while avoiding or reducing an eccentric or inclined position of the shaft. At the same time, despite the small play, due to the at least one chamfer between the outer side of the shaft and the guide recess, a sufficient passage can be provided, formed by the space between the at least one chamfer and the guide recess, which serves as the passage for the second connection.

[0093] In one embodiment, the annular projections each have two or three chamfers in the circumferential direction.

[0094] In one embodiment (without annular projections), the shaft has at least one chamfer in the circumferential direction, wherein the second connection comprises a passage which is formed by a space between the at least one chamfer and the guide recess. As already explained, the at least one chamfer allows the play between the shaft and the guide recess to be kept sufficiently small, which allows better centering of the shaft, i.e. while avoiding or reducing an eccentric or inclined position of the shaft. At the same time, despite the small play, due to the at least one chamfer between the outer side of the shaft and the guide recess, a sufficient passage can be provided, formed by the space between the at least one chamfer and the guide recess, which serves as the passage for the second connection.

[0095] In one embodiment, the shaft has two or three chamfers in the circumferential direction.

[0096] In one embodiment, the second connection comprises a bore extending through the head of the intermediate valve member, which bore at least partially forms a valve chamber passage connected to the valve chamber and opens with one end on a side of the head facing the intermediate part.

[0097] In one embodiment, the valve chamber passage extends in the intermediate valve member such that the valve chamber passage opens into a gap annular space in the closed position of the intermediate valve member, which gap annular space is formed between the intermediate part and the head in the closed position of the intermediate valve member and is radially delimited by the first and the second annular sealing surface.

[0098] In one embodiment, the fuel injection valve has an annular space delimited by the intermediate part, shaft and head in the closed position of the intermediate valve member, into which the high-pressure fuel inlet opens. List of characters

[0099] 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 an embodiment of a fuel injection valve; Fig.2 compared Figure 1 enlarged, the lower or downstream area of ​​the embodiment of the fuel injection valve framed there with a rectangle designated II; Fig. 3 a detail of a further embodiment of a fuel injection valve in a longitudinal section; Fig. 4(a)-(c) three configurations of the injection valve member of the Fig.3shown embodiment of the fuel injector; Fig. 5 shows a detail of a further embodiment of a fuel injector in a longitudinal section; Fig. 6 shows a detail of a further embodiment of a fuel injector in a longitudinal section. Description of exemplary embodiments

[0100] In the description of the figures, the same reference numerals are used for corresponding parts of the embodiments.

[0101] Figure 1shows an embodiment of a fuel injector 10.1 for the intermittent injection of fuel into a combustion chamber of an internal combustion engine. The fuel injector 10.1 has a housing 12 defining a longitudinal axis L with a housing body 14, a nozzle body 16, an injection valve part 15, 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 injection valve part 15. A union nut 22, supported on the injection valve part 15, receives the actuator receiving body 20 and is threaded onto the housing body 14. A union nut 23, supported on the nozzle body 16, is threaded onto the injection valve part 15.The housing body 14 and the actuator receiving body 20, as well as the latter and the injection valve part 15, abut one another at the end faces, are pressed against one another in a sealing manner by means of the union nut 22, and are aligned with one another in the direction of the longitudinal axis L. The nozzle body 16 and the injection valve part 15 are pressed against one another in a sealing manner by means of the union nut 23 and are aligned with one another in the direction of the longitudinal axis L. The outer shape of the housing 12 is at least approximately circular-cylindrical.

[0102] 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 injection valve part 15—to the injection valve seat 18. The high-pressure fuel inlet 24 is formed by a valve carrier 28, which carries a basket-like perforated filter 32 for retaining any foreign particles in the fuel.

[0103] A structure and function of the cartridge-shaped unit with the valve support 28 and the perforated filter 32 are disclosed in document WO2014 / 131497 A1. The high-pressure fuel inlet 24 and the valve support 28 with perforated filter 32 can also be designed as disclosed in document WO2013 / 117311 A1. The valve support 28 can also be a Figure 1A non-return valve (not shown) having a disc-shaped valve member which interacts with a valve seat formed on the valve carrier 28. The disc-shaped valve member of the check valve can have a bypass bore. The check valve can allow fuel supplied via a high-pressure feed line to flow into the high-pressure chamber 26 virtually unhindered, but can prevent fuel from flowing out of the high-pressure chamber 26 into the high-pressure feed line except through the bypass. One possible embodiment of the high-pressure fuel inlet 24 and a check valve, as well as a rod filter instead of the perforated filter 32, is known from document WO2009 / 033304 A1. The corresponding disclosure of the above-mentioned documents is incorporated into the present disclosure by reference.

[0104] 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.

[0105] A dimensioning and operation of the discrete storage chamber 34 together with a check valve with bypass is disclosed in document WO2007 / 009279 A1; the corresponding disclosure is incorporated by reference into the present disclosure.

[0106] Instead of a check valve, a stationary, immovable throttle can also be provided in certain embodiments.

[0107] In a recess of the actuator receiving body 20, an electrically operated actuator arrangement 38 is accommodated, which, 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 arrangement 38, is intended to close a low-pressure outlet 42 in order to separate a valve chamber 44 from a low-pressure fuel return 46 (see Figure 2 ) and to release the low-pressure outlet 42 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 eccentric to the longitudinal axis L.

[0108] Parallel to the discrete storage chamber 34, which is arranged at least partially eccentrically with respect to the longitudinal axis L of the housing 12 and thus of the fuel injection valve 10.1, a channel 52 runs from an electrical connection 50 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.

[0109] The tappet 40 extends through the bottom of the cup-shaped actuator receiving body 20, which forms a guide element for the tappet 40. The tappet 40 has guide vanes projecting in the radial direction, 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 42 to the low-pressure fuel return 46.

[0110] Figure 2 shows an enlarged section of the fuel injection valve of Figure 1 in the area of ​​the rectangle marked II.

[0111] The conical injection valve seat 18 is formed on the injection valve part 15 and is directly connected to the storage chamber 34 and thus to the high-pressure fuel inlet 24 via the flow channel 36. The injection valve seat 18 therefore forms a tapered section of the interior of the injection valve part 15, so that a first bore section 61 is arranged above or upstream of this tapered section, and a second bore section 62 with a smaller transverse diameter than the first bore section 61 is arranged below or downstream of this tapered section.

[0112] An injection valve member 56 with a conical valve sealing surface 57 is arranged in the housing 12 and is adjustable in the direction of the longitudinal axis L. Following the valve sealing surface 57, the injection valve member 56 has a needle 58 which projects into a nozzle chamber 17 of the nozzle body 16 arranged downstream of the injection valve seat 15 and the second bore section 62. The valve sealing surface 57 is designed to cooperate sealingly with the injection valve seat 18 to connect the nozzle chamber 17 to the high-pressure chamber 26 and to separate the nozzle chamber 17 from the high-pressure chamber 26.

[0113] The injection valve member 56 has a shoulder 59 facing away from the conical valve sealing surface 57, against which a compression spring 63 rests at one end. The other end of the compression spring 63 is supported on the end face of a guide sleeve 64 forming a guide part. The compression spring 63 applies a closing force to the injection valve member 56, acting in the direction of the injection valve seat 18. On the other hand, 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.

[0114] In the guide part 64, a double-acting control piston 68 formed on the injection valve member 56 is guided displaceably along the longitudinal axis L in 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. 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.

[0115] The nozzle body 16 has a plurality of first injection openings 161 extending from the nozzle chamber 17 and a plurality of second injection openings 162 extending from the nozzle chamber 17. The first injection openings 161 are arranged higher than or upstream of the second injection openings 162 with respect to the longitudinal axis L. The second injection openings 162 have a smaller (minimum) diameter than the first injection openings 161 and can be used for a pilot injection or, when operating with gas as the main fuel, for a pilot jet injection. The needle 58 is guided with a sliding fit in a sub-nozzle chamber 163, so that the side wall 581 of the needle 58 interacts in a quasi-sealing manner with the side wall 164 of the sub-nozzle chamber 163 to close and open the first injection openings 161 and / or the second injection openings 162. In the Figure 2In the embodiment shown, the needle 58 can selectively close the first injection openings 161 or the first and second injection openings 161, 162 by adjusting the injection valve member 56 along the longitudinal axis L. Accordingly, the needle 58 can selectively open 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 by adjusting the injection valve member 56 along the longitudinal axis L. In particular, the injection valve member 56 can be moved into a Figure 1 shown closed position, in which both the first and the second injection openings 161, 162 are closed and the nozzle chamber 17 is separated from the high-pressure chamber 26 by the sealing contact of the valve sealing surface 57 on the injection valve seat 18.

[0116] The nozzle chamber 17 has an upper nozzle chamber 165 with a larger diameter, arranged upstream of the lower nozzle chamber 163, which connects to the lower nozzle chamber 163 via a conical step. The diameter of the upper nozzle chamber 165 corresponds to the diameter of the second bore section 62 of the injection valve part 15, so that the upper nozzle chamber 165 is aligned with the second bore section 62.

[0117] The needle 58 has an inner bore 582 oriented along the longitudinal axis L, which extends from the lower end 583 of the needle 58. In the side wall, the needle 58 has transverse bores 584, which open into the upper nozzle chamber 165 and thus connect the inner bore 582 with the upper nozzle chamber 165. In the first open position of the injection valve member 56, in which the second injection openings 162 are open, the inner bore 582 connects the second injection openings 162 to the high-pressure chamber 26 via the lower nozzle chamber 163 and the upper nozzle chamber 165. In the second open position of the injection valve member 56, in which the first and second injection openings 161, 162 are open, the inner bore 582 connects the first and second injection openings 161, 162 to the high-pressure chamber 26 via the lower nozzle chamber 163 and the upper nozzle chamber 165.

[0118] The nozzle chamber 17 is designed like a blind hole with a bottom 171. In the illustrated closed position of the injection valve member 56, the nozzle chamber 17 has a free space 166 bounded by the lower end 583 of the needle 58 and the bottom 171, which is connected to the inner bore 582. The nozzle chamber 17 has an undercut at the downstream end, which forms the free space 166 in the closed position of the injection valve member 56.

[0119] A circular-cylindrical guide recess extends through the intermediate part 66 from the flat end face facing the control chamber 70 to the likewise flat end face facing away from the control chamber 70. A shaft 76 of a mushroom-shaped intermediate valve member 78 is guided in this recess. 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.

[0120] The intermediate valve member 78, together with the intermediate valve seat formed on the intermediate part 66, forms an intermediate valve 83. 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 deemed to be incorporated into the present disclosure by reference.

[0121] The (electro-)hydraulic control device described here can also be designed according to other electro-hydraulic control devices known from the prior art, such as WO2016 / 041739 A1.

[0122] Figure 3 shows a section of a further embodiment of a fuel injection valve 10.2, wherein the lower part of the fuel injection valve 10.2 is shown from the injection valve seat 18. In contrast to the Figure 2In the fuel injector 10.1 shown, the sub-nozzle chamber 163 has a first section 163.1 and a second section 163.2 arranged downstream of the first section 163.1, said second section having a smaller diameter than the first section 163.1. The second section 163.2 adjoins the first section 163.1 via a conical step. The second injection openings 162 extend from the second section 163.2 of the sub-nozzle chamber 163, and the first injection openings 161 extend from the first section 163.1 of the sub-nozzle chamber 163. The needle 58 accordingly has a first needle section 58.1, which is guided in a sliding fit in the first section 163.1 of the sub-nozzle chamber 163. A second needle section 58.2 is connected downstream of the first needle section 58.1 and can be guided in a sliding fit in the second section 163.2 of the sub-nozzle chamber 163. In Figure 3the injection valve member 56 is shown in a closed position in which the first injection openings 161 are closed by the first needle section 58.1 and the second injection openings 162 are closed by the second needle section 58.2.

[0123] The first and second needle sections 58.1, 58.2 are connected to one another via a conical step. In certain embodiments, the conical step connecting the first and second needle sections 58.1, 58.2 can correspond to the conical step connecting the first section 163.1 and the second section 163.2 of the nozzle chamber 163. As an alternative to the conical step, a vertical step is also possible between the needle sections 58.1, 58.2 and / or between the first and second sections 163.1, 163.2 of the nozzle chamber 163.

[0124] As in Figure 3As can be seen, the second injection openings 162 each have a first opening section 162.1 extending from the nozzle chamber 17 or from the second section 163.2 of the sub-nozzle chamber 163, and a second opening section 162.2 adjoining the first opening section 162.1, which opens into the outer wall of the nozzle body 16 and thus into the combustion chamber of the internal combustion engine. The diameter of the second opening section 162.2 is larger than the diameter of the first opening section 162.1, so that the second injection openings 162 have a profile that widens stepwise toward the combustion chamber of the internal combustion engine. The first opening section 162.1 and the second opening section 162.1 adjoin one another via a conical gradation. However, it is also conceivable that the opening sections 162.1, 162.2 are connected to each other via a vertical step.It is also conceivable that the outwardly widening conical step, whose opening angle can be varied, forms the entire second opening section. Due to the first opening section 162.1, the second injection openings 162 have a smaller minimum diameter than the first injection openings 161. The second injection openings 162 can therefore be used for pre-injection or pilot injection, while the first injection openings 161 (together with the likewise open second injection openings 162) can be used for a main injection with liquid fuel.

[0125] The nozzle chamber 17 is designed as a blind hole with a bottom 171. In the Figure 3 In the closed position of the injection valve member 56 shown, a free space 166 is formed in the nozzle chamber 17, which is delimited by the lower end of the needle 583 and the base 171. In contrast to the Figure 2In the fuel injector 10.1 shown, the base 171 is curved so that the free space 166 has a hemispherical profile. However, it is also possible for the free space 166 to be as shown in Figure 2 is trained.

[0126] The needle 58 has, as in the fuel injection valve 10.1, Figure 2 an inner bore 582 and transverse bores 584.

[0127] The Figures 4(a)-(c) show three positions of the injection valve member 56 of the Figure 3 shown embodiment of the fuel injector 10.2.

[0128] Figure 4(a) shows a section of the fuel injection valve 10.2 in the Figure 3 shown closed position, in which both the first injection openings 161 (by the first needle section 58.1) and the second injection openings 162 (by the second needle section 58.2) are closed.

[0129] Figure 4(b)shows the fuel injector 10.2 with the injection valve member 56 in a first open position, in which the injection valve member 56 is raised along the longitudinal axis L such that the second injection openings 162 are open, while the first injection openings 161 continue to be closed by the first needle section 58.2. The valve sealing surface 57 is raised from the injection valve seat 18. In the first open position shown, fuel can therefore pass from the high-pressure chamber 26 via the second bore section 62 or the upper nozzle chamber 165, the inner bore 582 and the lower nozzle chamber 163 or the second section 163.2 of the lower nozzle chamber 163 into the second injection openings 162, in order to be injected from there into the combustion chamber of the internal combustion engine.

[0130] Figure 4(c)shows the fuel injector 10.2 with the injection valve member 56 in a second open position, in which the injection valve member 56 is raised higher along the longitudinal axis L, so that in addition to the second injection openings 162, the first injection openings 161 are also open. The needle 58 continues to be guided in a sliding fit via the first needle section 58.1 in the sub-nozzle chamber 163 or in the first section 163.1 of the sub-nozzle chamber 163. The second needle section 58.2, however, is no longer located in the second section 163.2 of the sub-nozzle chamber 163, but is arranged in the first section 163.1 of the sub-nozzle chamber 163 and in the conical step between the first and second sections 163.1, 163.2 of the sub-nozzle chamber 163 due to the lifting of the injection valve member 56. As in Figure 4(c)As can be seen, in the second open position shown, fuel can pass from the high-pressure chamber 26 via the second bore section 62 or the upper nozzle chamber 165, the transverse bores 584, the inner bore 582 and the lower nozzle chamber 163 into both the first injection openings 161 and the second injection openings 162 in order to be injected from there into the combustion chamber of the internal combustion engine.

[0131] By appropriately configuring the needle 58, for example, with a longer second needle section 58.2, in particular such that the combined axial length of the second needle section 58.2 and the conical step between the first and second needle sections is longer than the axial distance between the first and second injection openings 161, 162, a further embodiment can achieve that the first injection openings 161 are opened first, while the second injection openings 162 are still closed. In such an embodiment, the first injection openings 161 can accordingly have a smaller minimum diameter than the second injection openings 162.

[0132] Figure 5shows a section of a further embodiment of a fuel injector 10.3, wherein the lower part of the fuel injector 10.3 is shown from the injector seat 18. The needle 58 of the fuel injector 10.3 has a sleeve 585, which is made of steel or another suitable material and which is arranged at least partially circumferentially around a lower part of the first needle section 58.1. The sleeve 585 is designed to cooperate with the side wall 164 of the nozzle chamber 17 or the sub-nozzle chamber 163 for closing and opening the first injection openings 161 and the second injection openings 162, wherein the sleeve 585 can be subjected to a clamping force directed radially against the side wall 164 of the nozzle chamber 17 or the sub-nozzle chamber 163.

[0133] The sub-nozzle chamber 163 further has two undercuts, through which two free spaces 166.1 and 166.2 are formed. The first free space 166.1 is similar to the free space 166 of the Figure 2 shown fuel injector 10.1 is formed at the bottom 171 of the nozzle chamber 17. The second free space 166.2 is formed between the first section 163.1 and the second section 163.2 of the sub-nozzle chamber 163. In the fuel injector 10.3, the second injection openings 162 are arranged in the first section 163.1 of the sub-nozzle chamber 163. However, it is also conceivable to arrange the second injection openings in the second section 163.2 and to use the sleeve 585 only to close the first injection openings 161. It is also conceivable to attach a second sleeve, which can be used to close the second injection openings, at least partially around the circumference of a part of the second needle section 58.2.

[0134] Figure 6shows a section of another embodiment of a fuel injector 10.4, wherein the lower part of the fuel injector 10.4 is shown starting from the injector seat 18. In the fuel injector 10.4, the first injection openings 161 and the second injection openings 162 each extend from the nozzle chamber 17 via trough-shaped recesses 1611, 1621, preferably with a small volume. The transitions between the injection openings 161, 162 and the side wall 164 of the nozzle chamber 17 are rounded. In particular, the transitions between the trough-shaped recesses 1611, 1621 and the injection openings 161, 162 are rounded.

Claims

1. Fuel injection valve (10.1, 10.2, 10.3, 10.4) 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 (24), an injection valve seat (18) and a nozzle body (16), a high-pressure chamber (26) arranged in the housing (12), which extends from the high-pressure fuel inlet (24) to the injection valve seat (18), an injection valve member (56) arranged in the housing (12) so as to be adjustable in the direction of the longitudinal axis (L) and having a valve sealing surface (57), a pressure spring (63) which exerts a closing force on the injection valve member (56) in the direction towards the injection valve seat (18), a hydraulic control device (72) for controlling the movement of the injection valve member along the longitudinal axis (L), wherein the injection valve member (56) has a needle (58) arranged downstream of the valve sealing surface (57) and projecting into a nozzle chamber (17) arranged downstream of the injection valve seat (18), wherein the valve sealing surface (57) is designed to cooperate sealingly with the injection valve seat (18) to connect the nozzle chamber (17) to the high-pressure chamber (26) and to separate the nozzle chamber (17) from the high-pressure chamber (26), wherein the nozzle body (16) has at least one first injection opening (161) extending from the nozzle chamber (17) and at least one second injection opening (162) extending from the nozzle chamber (17) for injecting fuel into the combustion chamber of the internal combustion engine, wherein the at least one first injection opening (161) and the at least one second injection opening (162) are arranged at different heights in relation to the longitudinal axis (L), wherein the needle (58) is designed to interact with a side wall (164) of the nozzle chamber (17) to close and open the at least one first injection opening (161) and / or the at least one second injection opening (162), wherein the fuel injection valve (10.1) further comprises: a guide part (64) in which a control piston (68) of the injection valve member (56) is guided in a sliding fit, 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), an electrically operable actuator arrangement (38) for connecting a valve chamber (44) to and separating the valve chamber (44) from a low-pressure fuel return line (46), characterised in that the hydraulic control device (72) has 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 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 releases a connection between a high-pressure fuel admission connected to the high-pressure chamber (26) and the control chamber (70) and in a closed position interrupts the connection between the high-pressure fuel admission and the control chamber (70) and separates the control chamber (70) from the valve chamber (44) - except for a throttle passage.

2. Fuel injection valve (10.1-10.4) according to claim 1, characterised in that the at least one first injection opening (161) and the at least one second injection opening (162) have different minimum diameters, wherein the at least one second injection opening (162) is preferably arranged downstream of the at least one first injection opening (161) and has a smaller minimum diameter than the minimum diameter of the at least one first injection opening (161).

3. Fuel injection valve (10.1-10.4) according to one of the preceding claims, characterised in that the needle (58) is designed to close the at least one first injection opening (161) and the at least one second injection opening(162) in a closed position of the injection valve member (56), in a first open position of the injection valve member (56), to open the at least one second injection opening (162) and to close the at least one first injection opening (161), in a second open position of the injection valve member (56), to open the at least one second injection opening (162) and the at least one first injection opening (161).

4. Fuel injection valve (10.1-10.4) according to claim 3, characterised in that the needle (58) has an internal bore (582) oriented substantially along the longitudinal axis (L), which extends from a lower end (583) of the needle (58) and is designed to connect the at least one second injection orifice (162) with the high-pressure chamber (26) in the first open position of the injection valve member (56), and to connect the at least one second injection opening (162) and the at least one first injection opening (161) with the high-pressure chamber (26) in the second open position of the injection valve member (56).

5. Fuel injection valve (10.1-10.4) according to claim 4, characterised in that the nozzle chamber (17) has an upper nozzle chamber (165) arranged downstream of the high-pressure chamber (26) and a lower nozzle chamber (163) arranged downstream of the upper nozzle chamber (165), wherein the lower nozzle chamber (163) is connected to the upper nozzle chamber (165) via the inner bore (582) of the needle (58), wherein the at least one first injection opening (161) and the at least one second injection opening (162) extend from the lower nozzle chamber (163), wherein the inner bore (582) of the needle (58) is preferably connected to the upper nozzle chamber (165) via at least one transverse bore (584) in a side wall (581) of the needle, wherein the needle (58) is preferably guided in a sliding fit in the lower nozzle chamber (163).

6. Fuel injection valve (10.1-10.4) according to claim 5, characterised in that the diameter of the nozzle chamber (17) decreases at the transition from the upper nozzle chamber (165) to the lower nozzle chamber (163), preferably via a conical step.

7. Fuel injection valve (10.2, 10.3) according to claim 5 or 6, characterised in that the lower nozzle chamber (163) has a first section (163.1) and a second section (163.2) arranged downstream of the first section (163.1) with a diameter reduced in comparison to the first section (163.1), wherein the at least one second injection opening (162) preferably extends from the second section (163.2) of the lower nozzle chamber (163), wherein the at least one first injection opening (161) preferably extends from the first section (163.1) of the lower nozzle chamber (163).

8. Fuel injection valve (10.2, 10.3) according to claim 6 or 7, characterised in that the needle (58) has a first needle section (58.1), which is guided in a sliding fit in the first section (163.1) of the lower nozzle chamber (163), and a second needle section (58.2) adjoining the first needle section (58.1), which can be guided in a sliding fit in the second section (163.2) of the lower nozzle chamber (163), wherein the second needle section (58.2) is preferably guided between the closed position and the first open position of the injection valve member (56) in a sliding fit in the second section (163.2) of the lower nozzle chamber (163), wherein the first and second needle sections (58.1, 58.2) preferably connect to each other via a conical step.

9. Fuel injection valve (10.1-10.4) according to one of the preceding claims 3 to 8, characterised in that the nozzle chamber (17) is formed in a blind hole-like manner with a floor (171), wherein, in the closed position of the injection valve member (56), the nozzle chamber (17) has a free space (166, 166.1) which is delimited by a lower end (583) of the needle (58) and the floor (171) of the blind hole-like nozzle chamber (17).

10. Fuel injection valve (10.1, 10.3, 10.4) according to one of the preceding claims, characterised in that the nozzle chamber (17) has an undercut at a downstream end.

11. Fuel injection valve (10.1-10.4) according to one of the preceding claims, characterised in that the injection valve seat (18) is formed in an injection valve part (15), wherein the nozzle body (16) is releasably fastened to the injection valve part (15), preferably via a cap nut (23).

12. Fuel injection valve (10.3) according to one of the preceding claims, characterised in that the needle (58) has a sleeve (585) which is designed to cooperate with the side wall (164) of the nozzle chamber (17) to close and open the at least one first injection opening (161) and / or the at least one second injection opening (162), wherein the sleeve (585) is preferably subjected to a clamping force directed radially against the side wall (164) of the nozzle chamber (17).

13. Fuel injection valve (10.2) according to one of the preceding claims, characterised in that the at least one second injection opening (162) has a first opening section (162.1) extending from the nozzle chamber (17) and a second opening section (162.2) adjoining the first opening section (162.1) , the diameter of the second opening section (162.2) being greater than the diameter of the first opening section (162.1).

14. Fuel injection valve (10.4) according to one of the preceding claims, characterised in that the at least one first injection opening (161) and / or the at least one second injection opening (162) extend from the nozzle chamber (17) via a trough-shaped recess (1611, 1621).

15. Fuel injection valve (10.1) according to one of the preceding claims, characterised in that the intermediate valve member (78) in the open position releases a second connection between the high-pressure fuel admission and the valve chamber (44) and in the closed position interrupts the second connection between the high-pressure fuel admission and the valve chamber (44).