DE102023119598A1 - injector for injecting fuel - Google Patents

Abstract

The present invention relates to an injector for injecting fuel, comprising: an injector housing, an armature element, a throttle, a valve, and an armature counterpart, wherein both the armature element and the armature counterpart have a through-channel running in the axial direction for conducting fuel and wherein a spring element is provided which is arranged in the through-channel of the armature element and in the through-channel of the armature counterpart, wherein a sleeve, the so-called armature sleeve, is arranged in the through-channel of the armature element and/or a sleeve, the so-called pole core sleeve, is arranged in the through-channel of the armature counterpart.

Description

The present invention relates to an injector for injecting fuel, in particular for injecting a gas, preferably for directly injecting hydrogen. It can be provided that the injector is designed to inject fuel into a combustion chamber of an internal combustion engine.

As emissions limits become increasingly strict worldwide and ambitious climate protection goals are set, the environmental requirements for internal combustion engines are constantly increasing. The goal in the foreseeable future is to have low-emission or even emission-free drive technologies that meet even the strictest emissions limits and make a significant contribution to achieving climate protection goals. For technologies that work with combustion, these goals can only be achieved by using climate-neutral, renewably produced fuels that do not cause any emissions along the entire value chain (so-called "zero emissions" fuels).

With current conventional gasoline, diesel and gas engines, the requirements for emission-free combustion cannot be met - even when using so-called e-fuels, e.g. a synthetically produced OME fuel, the production of which only requires renewable energy - because the emission of harmful exhaust gases such as nitrogen oxides (NO _x ), unburned hydrocarbons (UHC) and soot cannot be completely reduced with today's technologies.

In principle, battery-powered drives meet the zero-emissions directive during operation and are on the rise, especially in the passenger car sector. However, if the entire value chain is considered, the production of (lithium) batteries is very expensive in terms of energy and problematic from an environmental point of view, as the extraction of raw materials in particular causes severe environmental damage and the extraction of the raw materials required for the batteries is not sustainable. In addition, the power-to-weight ratio of batteries that can be achieved today does not allow them to be used in machines with high (peak) power requirements.

Fuel cell-powered drives with a supply of renewably generated hydrogen meet the specified climate protection goals and are already in use to a very limited extent. However, this concept also has some disadvantages, such as low peak power and low economic efficiency compared to today's diesel drives.

The focus has therefore shifted to hydrogen combustion engines, which represent a promising alternative drive system. However, to date these have only existed in very small numbers or as demonstrators with a low level of maturity. Hydrogen produced using renewable energies would meet all the requirements of "zero emissions" because it can be burned without emissions.

In the passenger car sector, for example, there are hydrogen engines with external mixture formation (PFI = port fuel injection), in which the fuel is well mixed with air in sufficient time before entering the combustion chamber. Hydrogen engines with direct injection of the fuel into the combustion chamber (internal mixture formation, DI = direct injection) play practically no role today, but compared to the PFI concept, they have, among other things, higher efficiency, more stable combustion and the elimination of the risk of backfiring in the intake tract.

In direct-injection hydrogen engines, a distinction is typically made with regard to the maximum injection pressure in the injector (< 60 bar: low pressure, > 60 bar: high pressure), although the limits are not clearly defined and the transitions are fluid. Higher pressures offer the potential for a shortened injection time in a later phase of compression at higher combustion chamber pressures, which results in increased efficiency and improved combustion stability. However, the overall efficiency decreases if compression of the hydrogen is necessary beforehand.

• • Verwendung bekannter Technologien mit hohem Reifegrad und bestehender Produktionsanlagen
• • unbegrenzte Verfügbarkeit des Wasserstoffs durch Elektrolyse von Wasser
• • Nutzung des bestehenden Tankstellensystems möglich (nach entsprechender Umrüstung) mit schnellen Tankzeiten
• • (fast) emissionsfreie Umwandlung des Wasserstoffs in der Verbrennung möglich, da CO2-neutral, nur minimale CO, UHC-, Partikel- und Ruß-Emissionen (lediglich verursacht durch Schmierstoffe im Zulaufsystem, unterhalb der Messgrenze) und nur minimale NOx-Emissionen durch geeignetes Verbrennungsverfahren (ggf. mit Abgasrückführung, SCR-Katalysator)
• • deutlich geringere Anforderung an Reinheit des Wasserstoffs im Vergleich zu Brennstoffzellen-Antrieben
• • kein Bedarf an Platin zur Herstellung wie bei Brennstoffzellen

If the hydrogen is produced 100% from renewable energies, hydrogen combustion engines can operate in an almost climate-neutral manner. There are also numerous other advantages:

• • Use of known technologies with a high level of maturity and existing production facilities
• • unlimited availability of hydrogen through electrolysis of water
• • Use of the existing petrol station system possible (after appropriate conversion) with fast refueling times
• • (almost) emission-free conversion of hydrogen in combustion possible, as it is CO2-neutral, only minimal CO, UHC, particle and soot emissions (only caused by lubricants in the feed system, below the measuring limit) and only minimal NOx emissions through suitable combustion processes (if necessary with exhaust gas recirculation, SCR catalyst)
• • significantly lower requirements for hydrogen purity compared to fuel cell drives
• • no need for platinum for production as with fuel cells

• • geringes Molekulargewicht von Wasserstoff, dadurch eine geringe Dichte einhergehend mit einer geringen volumetrischen Energiedichte (bei hoher massenspezifischer Energiedichte); siehe Tabelle 1
• • Bereitstellung eines demzufolge hohen Volumenstroms bei der Einblasung von Wasserstoff
• • entsprechende Bereitstellung von großen Strömungsquerschnitten im Injektor und damit benötigter deutlich größerer Hübe des Aktuators als bei konventionellen Antriebsarten
• • einhergehende Entwicklung einer deutlich stärkeren Aktuatoreinheit bei gleichzeitig begrenztem Bauraum
• • je nach Anwendung aufgrund langer Einspritz- und damit Bestromungszeiten der Aktuatoreinheit ein hoher thermischer Wärmeeintrag und somit benötigtes Wärmeabfuhrkonzept
• • fehlende Kühlung der Injektoreinheit durch Kraftstoff speziell bei Einspritzung von nicht-kryogenem Wasserstoff
• • Dichtheit des Gesamtsystems / Verhinderung von externen Leckagen, v. a. im Hinblick auf Sicherheitsaspekte (Brand- und Explosionsgefahr aufgrund aus dem System austretenden Wasserstoff)
• • erhöhte Verschleißgefahr an Führungen bewegter Bauteile aufgrund der praktisch nicht vorhandenen Schmierwirkung von Wasserstoff
• • deutlich stärkere Neigung bewegter Bauteile zum Prellen an mechanischen Anschlägen in Gasinjektoren im Vergleich zu Injektoren mit Flüssigkraftstoffen durch geringe Dämpfwirkung bei der Gaskompression
• • Materialbeständigkeit gegenüber Wasserstoff nötig im Hinblick auf die Gefahr einer Wasserstoffversprödung in mechanisch beanspruchten / druckbeaufschlagten Bauteilen (reduzierte Festigkeit) oder durch chemische Reaktion des Wasserstoffs mit in der Kupferspule des Aktuators vorhandenem Sauerstoff (Wasserstoffkrankheit des Kupfers)
• • Gemischaufbereitung im Brennraum / Beeinflussung des Einblasstrahls / Zündverhalten bei Kleinstmengeneinblasung
• • hohe lokale Temperaturen im Brennraum können zu erhöhter thermischer NOx-Bildung führen, was die Entwicklung eines geeigneten Brennverfahrens erforderlich macht (zum Beispiel Ladungsschichtung zur Vermeidung stöchiometrischer Verbrennung, Abgasrückführung, Abgasnachbehandlung)

Tabelle 1: Massen- und volumenspezifischer Heizwert von Diesel und Wasserstoff Diesel Wasserstoff (bei 25 °C) Heizwert in MJ/kg 43.0 120.0 Heizwert in MJ/m³ 35'819 9.8 bei 1 bar 287.7 bei 30 bar 2464.4 bei 300 bar In addition to these numerous advantages over other drive concepts, there are also some challenges that need to be overcome in the development of hydrogen combustion engines:

• • low molecular weight of hydrogen, resulting in a low density accompanied by a low volumetric energy density (with high mass-specific energy density); see Table 1
• • Provision of a high volume flow when injecting hydrogen
• • corresponding provision of large flow cross-sections in the injector and thus required significantly larger strokes of the actuator than with conventional drive types
• • accompanying development of a significantly stronger actuator unit with limited installation space
• • depending on the application, due to long injection and thus power supply times of the actuator unit, a high thermal heat input and thus required heat dissipation concept
• • lack of cooling of the injector unit by fuel, especially when injecting non-cryogenic hydrogen
• • Tightness of the entire system / prevention of external leaks, especially with regard to safety aspects (risk of fire and explosion due to hydrogen escaping from the system)
• • increased risk of wear on guides of moving components due to the practically non-existent lubricating effect of hydrogen
• • significantly greater tendency of moving components to bounce on mechanical stops in gas injectors compared to injectors with liquid fuels due to low damping effect during gas compression
• • Material resistance to hydrogen is necessary in view of the risk of hydrogen embrittlement in mechanically stressed / pressurized components (reduced strength) or due to chemical reaction of hydrogen with oxygen present in the copper coil of the actuator (hydrogen disease of copper)
• • Mixture preparation in the combustion chamber / influencing the injection jet / ignition behavior with minimal injection
• • high local temperatures in the combustion chamber can lead to increased thermal NOx formation, which requires the development of a suitable combustion process (e.g. charge stratification to avoid stoichiometric combustion, exhaust gas recirculation, exhaust gas aftertreatment)

Table 1: Mass and volume specific calorific value of diesel and hydrogen Diesel hydrogen (at 25 °C) calorific value in MJ/kg 43.0 120.0 calorific value in MJ/m ³ 35,819 9.8 at 1 bar 287.7 at 30 bar 2464.4 at 300 bar

The aim of the present invention is to at least partially overcome or mitigate the disadvantages listed above. In particular, the problem of the much more pronounced wear between the parts moving back and forth and the problem of the pronounced bouncing that occurs with gas injectors compared to injectors with liquid fuels are to be addressed. The liquid fuels already have a dampening or lubricating effect per se, so that an element surrounded by the fuel is dampened in its movement and experiences less wear when sliding along another element.

The present invention succeeds in solving or mitigating at least one of the above problems. For this purpose, an injector is to be provided which has all the features of independent claim 1. Advantageous embodiments of the present invention can be found in the subclaims that follow.

The present invention relates to an injector for injecting fuel, preferably for injecting a gaseous fuel, in particular hydrogen, which has an injector housing for receiving and arranging injector components, an anchor element which is arranged in the injector housing so as to be movable along an axial direction of the injector and is designed to close or release a throttle by an axial movement along the injector housing in order to allow fuel to flow through this throttle, a valve, in particular a solenoid valve, which is designed to separate the anchor element from a closing in to transfer a releasing state of the throttle and vice versa, and comprises an armature counterpart which is arranged on the side of the armature element opposite the throttle, wherein in a state of the armature element closing the throttle a gap running in the axial direction is formed between the armature counterpart and the armature element, both the armature element and the armature counterpart have a through-channel running in the axial direction for conducting fuel, and a spring element arranged in the through-channel of the armature element and in the through-channel of the armature counterpart is provided in order to force the armature counterpart and the armature element apart and to press the armature element into a state closing the throttle. The injector is characterized in that a sleeve, the so-called armature sleeve, is arranged in the through-channel of the armature element and/or a sleeve, the so-called pole core sleeve, is arranged in the through-channel of the armature counterpart, wherein the at least one sleeve is arranged in its through-channel such that it protrudes in the axial direction relative to the component receiving it and projects into the gap.

The protrusion of the sleeve into the gap between the armature element and the armature counterpart ensures that even when the injector is in the open state, in which the armature element has been moved towards the armature counterpart due to the active valve, a residual air gap remains between the armature element and the armature counterpart, since the armature element strikes against the protruding section of the sleeve.

It is no longer necessary to adjust the residual air gap using foils or shims arranged in the intermediate area between the facing surfaces of the anchor element and the anchor counterpart, since the protruding part of the sleeve ensures the desired residual air gap.

It is clear to the person skilled in the art that the residual air gap can be created both by a sleeve inserted into the anchor element and by a sleeve inserted into the anchor counterpart, wherein the invention also covers the case that a respective sleeve is provided in both the anchor element and the anchor counterpart, at least one of which protrudes from the component receiving it (i.e. anchor element or anchor counterpart) in the direction of the gap.

The provision of a sleeve arranged in the passage channel of the anchor element or anchor counterpart thus enables the creation of a residual air gap in which the work steps typically used for dimensioning and applying corresponding films or shims to the mutually facing end faces of the anchor element and anchor counterpart no longer have to be carried out.

The exact adjustment of the residual air gap serves to influence the magnetic characteristic curve and thus characterizes the properties when opening or closing the injector.

In a fuel injector with a magnetic valve, the magnetic characteristic plays a relevant role in the function of the valve itself. The magnetic valve works on the basis of electromagnetism, and the magnetic characteristic helps to understand how the magnetic field varies depending on the applied current.

The magnetic characteristic describes how the magnetic field (the magnetic flux density B) in a material changes depending on the applied magnetic field strength H. It indicates how much magnetism the material "conducts" or lets through when a certain magnetic field is applied.

In practice, the solenoid valve is controlled by a current that generates a magnetic field strength. This field strength pulls a magnetic metal core (the armature or armature element) towards the armature counterpart, so that the valve opens or closes. The magnetic characteristic curve can provide information about how strong the current must be to achieve a certain movement of the armature element (and thus a certain valve position).

According to the invention, it can be provided that the sleeve is fastened in the through-channel for conducting fuel, in particular a gaseous fuel, by means of a press fit, clearance fit or friction welding in the armature counterpart or the armature element. As a rule, the through-channel has a step-like cross-sectional widening or reduction in order to provide a projection for attaching the sleeve so that it is fixed in the axial direction of the injector.

According to an advantageous modification of the present invention, it can be provided that the at least one sleeve has an inwardly projecting projection at its end remote from the gap in order to enable the spring element to be attached there.

This makes the typically used stop disc for the needle spring obsolete, since this function is taken over by the radially inwardly extending notches of the sleeve.

Furthermore, according to an advantageous embodiment of the present invention, it can be provided that the at least one sleeve has an inner diameter at least in sections in order to guide and align the spring element, preferably a spiral spring. The inner diameter of the sleeve can be adapted to an outer circumference of a spiral spring or correspond to it, so that the spiral spring is guided by insertion into the sleeve and is arranged and fixed in a predetermined position.

According to an advantageous modification of the present invention, it can be provided that the at least one sleeve has a section in the axial direction that has a reduced wall thickness, so that damping occurs when an axial force compressing the sleeve acts. It can be provided that - viewed in the axial direction - the section with a reduced wall thickness is surrounded by sections with a wall thickness that is increased in comparison. A section with a regular (or thicker) wall thickness is therefore followed by the section with a reduced wall thickness, before another section with a thicker wall thickness follows.

The area of reduced wall thickness ensures that when an axial force acts on the sleeve, it is compressed and acts as a spring element. This reduces unwanted needle bounce and therefore improves the accuracy of the amount of fuel dispensed.

According to an optional modification of the present invention, it can be provided that the at least one sleeve is fixedly arranged in the component receiving it. It can therefore be provided that the armature sleeve is fixedly arranged in the armature element. It can also be provided that the pole core sleeve is fixedly arranged in the armature counterpart.

In this case, it can be provided, for example, that the sleeve is fastened in the element receiving it (anchor element or anchor counterpart) by means of a press fit, friction welding or the like.

According to a further development of the present invention, it can be provided that the at least one sleeve is arranged so as to be movable in the axial direction in the component receiving it, wherein a sleeve spring is preferably arranged at an end of the sleeve remote from the gap in order to urge the sleeve in the direction of the gap.

Thus, even when the injector is closed, in which the armature element closes the throttle with its needle, the gap formed between the armature element and the armature counterpart is overcome by the sleeve that can be moved in the axial direction. A sleeve spring can then be provided on the end of the sleeve that is movable in the axial direction that is opposite the gap, which is compressed when the injector is opened and the gap between the armature counterpart and the armature element is reduced as a result. Since with such a design the fuel guide through the respective through-channels of the armature sleeve or the pole core sleeve has no possibility of penetrating radially outwards into the residual air gap that remains when the injector is open, improved flow behavior with less turbulence is achieved.

Thus, the at least one sleeve that is movable in the axial direction ensures that, regardless of the state of the injector (open, closed or transition between open and closed), the fuel is guided without the formation of vortices between the anchor counterpart and the anchor element, which allows a more precise metering of the fuel to be delivered.

The sleeve, which is movable in the axial direction, can be guided by a support sleeve which partially extends into the passageway of the movable sleeve, which is fixedly arranged in the injector and has a corresponding recess for the attachment of the sleeve spring. In order to be able to easily vary the spring force which pushes the sleeve, which is movable in the axial direction, towards the gap between the anchor element and the anchor counterpart, an adjusting disk can be provided which defines the tension of the sleeve spring relative to the movable sleeve.

Furthermore, according to an advantageous modification of the present invention, it can be provided that the sleeve protrudes so far from the component receiving it (anchor element or anchor counterpart) that it penetrates into the through-channel of the other component provided with the through-channel (anchor counterpart or anchor element), preferably in order to provide guidance during a movement of the anchor in the axial direction, wherein preferably the outer diameter of the section of the sleeve protruding into the other component is matched to the inner diameter of the through-channel of the other component (e.g. corresponds to this) in order to allow a sliding movement of the other component relative to the penetrating sleeve section.

For example, a residual air gap can be set by a sleeve that protrudes on one side and overcomes the gap between the anchor element and the anchor counterpart. Furthermore, the exact axial position of the stop on the protruding sleeve during an opening process serves to influence the magnetic characteristic curve, so that the opening characteristic of the injector can be advantageously adjusted.

Furthermore, the overhang of the sleeve can be used to guide the component into which the sleeve penetrates with its overhang. For example, a pole core sleeve can protrude from the anchor counterpart in such a way that its overhang dips into the anchor element. If the area of the anchor element is matched to the dimensions of the overhang of the pole core sleeve penetrating into it, this guides the anchor element, which promotes a particularly reliable and low-maintenance implementation of the injector. Finally, the further guidance of the anchor element further reduces the likelihood of undesired jamming. It is clear to the expert that the anchor sleeve can of course also penetrate into the anchor counterpart, since this achieves the same advantages.

Furthermore, according to an optional development of the present invention, it can be provided that a non-magnetic or diamagnetic element is arranged between the end of the sleeve facing away from the gap and the component receiving the sleeve in order to interrupt a magnetic flux or to specifically redirect it, wherein the non-magnetic or diamagnetic element is a soft elastic element, for example an elastomer, an amorphous metal and/or a metallic glass. As a rule, this non-magnetic or diamagnetic element has the shape of an annular disk, so that the fuel to be dispensed by the injector can be guided through its inner recess. In addition, this element can also be used to define the fine positioning of the sleeve in the element receiving it in relation to the axial direction.

According to a further advantageous modification of the present invention, it can be provided that the mutually facing end faces of the anchor element and the anchor counterpart have a design that corresponds to one another, but are not smooth, wherein preferably the end face of the anchor element and the anchor counterpart have a step that rises in the axial direction.

By providing two end faces of the armature element and armature counterpart that correspond to each other but are not in the same plane, the magnetic characteristic curve can be influenced in a targeted manner. Using the example of stepped end faces, where the step rises in the axial direction, a residual air gap can be created in two different planes. This serves to specifically influence the magnetic characteristic curve.

Furthermore, according to the present invention, it can be provided that a radial gap extending in the axial direction is provided on the outer circumference of the at least one sleeve to the component receiving it in order to reduce or completely prevent a flow of magnetic field lines through the sleeve, preferably wherein the radial gap extends in the axial direction from the end facing the gap.

This gap or the radial gap between the outer circumference of the sleeve and the component receiving the sleeve (armature element or armature counterpart) also serves for the targeted control of magnetic field lines which, if the gap is present, do not pass through the sleeve or only pass through it to a very limited extent.

According to a further advantageous modification of the present invention, it can be provided that a sleeve, the so-called anchor sleeve, is arranged both in the through-channel of the anchor element and a sleeve, the so-called pole core sleeve, is arranged in the through-channel of the anchor counterpart, wherein each of the two sleeves protrudes from the respective component receiving it in the direction of the gap.

It is therefore intended that both the pole core sleeve and the armature sleeve protrude from the component that accommodates them in the direction of the gap and, when the injector is closed and the armature element with the needle is lifted off the throttle, they together define the remaining air gap between the armature element and the armature counterpart. Another advantage is that only the two sleeves come into contact with each other, which allows both the armature element and the armature counterpart to be made of materials that need to be less resistant to constant impact on one another.

Furthermore, according to a further modification of the invention, it can be provided that, when an anchor sleeve and a pole core sleeve are present, the two sleeves are arranged relative to one another in their respective through-channel such that the mutually facing end faces of the two sleeves contact one another when the injector is in the open state.

It can preferably be provided that, if an armature sleeve and a pole core sleeve are present, the outer diameter of the two sleeves is the same or different.

The invention further comprises an injector according to one of the preceding aspects, wherein the anchor element is designed in several parts and has a lower part facing the throttle and an upper part arranged between the lower part and the anchor counterpart, the upper part is movable in the axial direction relative to a sleeve inserted into the lower part, the sleeve in a closed state protrudes from the lower part in the axial direction and protrudes beyond the upper part of the multi-part anchor element, and the sleeve has a radial projection on the side facing away from the throttle, which corresponds to a corresponding recess in the upper part of the anchor element, so that when the upper part is moved in the direction of the anchor counterpart, the sleeve and the lower part of the anchor element connected thereto are moved in the direction of the anchor counterpart according to the principle of a hammer anchor, wherein an anchor spring is preferably provided which is designed to urge the upper part of the anchor element in the direction of the throttle.

The invention further relates to an internal combustion engine with a fuel injection, in particular with a gas direct injection, in particular with a hydrogen direct injection, comprising an injector according to one of the previously discussed aspects.

• 1A: eine schematische Schnittansicht eines Injektors nach dem Stand der Technik in einem geschlossenen Zustand,
• 1B: eine schematische Schnittansicht eines Injektors nach dem Stand der Technik in einem geöffneten Zustand,
• 2: eine schematische Schnittansicht eines erfindungsgemäßen Injektors mit einer in den Spalt vorstehenden Hülse,
• 3: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit zwei gegenüber zueinander angeordneten jeweils in den Spalt vorstehenden Hülsen,
• 4: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit einer Hülse, deren Überstand in das gegenüberliegende Bauteil eindringt,
• 5: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit einer Hülse, deren Überstand in das gegenüberliegende Bauteil eindringt und dort als Führung dient,
• 6: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit einer Hülse, die eine Querschnittsverminderung aufweist, um eine Dämpferfunktion zu erzeugen,
• 7: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit einer Hülse, die an ihrer vom Luftspalt abgewandten Seite an einer Isolationsscheibe anliegt,
• 8: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors, wobei beide einander gegenüber angeordneten Hülsen an ihrem jeweiligen vom Luftspalt abgewandten Ende eine nach innen ragende Einkragung aufweisen,
• 9A: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors in einem geschlossenen Zustand, bei dem die einander zugewandten Stirnflächen von Ankerelement und Ankergegenstück nicht planar ausgestaltet sind,
• 9B: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors in einem geöffneten Zustand, bei dem die einander zugewandten Stirnflächen von Ankerelement und Ankergegenstück nicht planar ausgestaltet sind,
• 10: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit einer Hülse, die eine Querschnittsverminderung aufweist, um eine Dämpferfunktion zu erzeugen,
• 11: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors, wobei zwischen der Hülse und dem die Hülse aufnehmenden Bauteil eine radial verlaufende Lücke vorgesehen ist,
• 12A: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors in einem geöffneten Zustand, wobei der Anker in Form eines Hammer-Ankers ausgebildet ist,
• 12B: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors in einem geschlossenen Zustand, wobei der Anker in Form eines Hammer-Ankers ausgebildet ist,
• 13: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit einer in Axialrichtung beweglichen Hülse, und
• 14: eine schematische Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Injektors mit einer in Axialrichtung beweglichen Hülse.

Further features, details and advantages of the invention will become apparent from the following description of the figures. They show:

• 1A : a schematic sectional view of a prior art injector in a closed state,
• 1B : a schematic sectional view of an injector according to the prior art in an opened state,
• 2 : a schematic sectional view of an injector according to the invention with a sleeve protruding into the gap,
• 3 : a schematic sectional view of a further embodiment of the injector according to the invention with two sleeves arranged opposite one another and each projecting into the gap,
• 4 : a schematic sectional view of a further embodiment of the injector according to the invention with a sleeve whose projection penetrates into the opposite component,
• 5 : a schematic sectional view of a further embodiment of the injector according to the invention with a sleeve, the projection of which penetrates into the opposite component and serves as a guide there,
• 6 : a schematic sectional view of a further embodiment of the injector according to the invention with a sleeve which has a cross-sectional reduction in order to produce a damper function,
• 7 : a schematic sectional view of a further embodiment of the injector according to the invention with a sleeve which rests on an insulating disk on its side facing away from the air gap,
• 8 : a schematic sectional view of a further embodiment of the injector according to the invention, wherein both sleeves arranged opposite one another have an inwardly projecting projection at their respective ends facing away from the air gap,
• 9A : a schematic sectional view of a further embodiment of the injector according to the invention in a closed state, in which the mutually facing end faces of the anchor element and anchor counterpart are not planar,
• 9B : a schematic sectional view of a further embodiment of the injector according to the invention in an open state in which the mutually facing end faces of the anchor element and anchor counterpart are not planar,
• 10 : a schematic sectional view of a further embodiment of the injector according to the invention with a sleeve which has a cross-sectional reduction in order to produce a damper function,
• 11 : a schematic sectional view of a further embodiment of the injector according to the invention, wherein a radially extending gap is provided between the sleeve and the component receiving the sleeve,
• 12A : a schematic sectional view of a further embodiment of the injector according to the invention in an opened state, wherein the anchor is designed in the form of a hammer anchor,
• 12B : a schematic sectional view of a further embodiment of the injector according to the invention in a closed state, wherein the anchor is designed in the form of a hammer anchor,
• 13 : a schematic sectional view of a further embodiment of the injector according to the invention with a sleeve movable in the axial direction, and
• 14 : a schematic sectional view of a further embodiment of the injector according to the invention with a sleeve movable in the axial direction.

The following detailed figure description of the 1 is explained using an injector for injecting a gaseous fuel, although it is clear to the person skilled in the art that the invention also includes an injector for injecting another fuel, for example a liquid fuel.

1A shows a longitudinal section of an injector 1 for injecting a gaseous fuel, for example hydrogen, into a combustion chamber. The injector 1 has an injector housing 2 (which also functions as a plunger tube) in which various components of the injector 1 are located. On the connection side, a fuel supply line (not shown) is provided for introducing a fuel into the injector 1. Firstly, the fuel or another combustible fluid (for example hydrogen) is fed through a hole in a cover 12 that runs approximately centrally in the injector housing 2 and can be screwed to the housing 2. The fuel introduced in this way is then fed through a through-channel of an armature counterpart 7 and a through-channel of the armature 3 to the end of the valve needle 4 that is remote from the connection side. The needle 4 and/or armature 3 can be designed in one or more parts. The needle 4 and armature 3 are preferably firmly connected to one another, e.g. by force fit, or are designed as a single piece. However, an embodiment with a freewheel between needle 4 and armature 3, so that the armature 3 only comes into contact with the needle 4 after a certain run-up distance and takes it along by force transmission through contact, is also conceivable and also covered by the invention.

Depending on the position of the anchor element 3 or the valve needle 4 relative to the valve plate 15, the at least one throttle 5 penetrating the valve plate 15 is closed or released. In the 1A In the state shown, the throttle 5 is closed by pressing the valve needle 4 against the valve plate 15, since the front side of the valve needle 4 covers the opening contour of the at least one throttle 5.

If the at least one throttle 5 is closed by the front side of the valve needle 4, the fluid flow of the fuel is stopped at this point of the injector 1 and there is no downstream flow of fuel beyond the valve plate 15. The injector is therefore in a closed state.

If, however, the throttle 5 is released, which is implemented by lifting the armature element 3 away from the valve plate 15 and by the resulting lifting of the valve needle 4, the fuel introduced into the injector 1 with a certain pressure flows out and exits via the at least one throttle 5 on the side of the valve plate 15 spaced apart from the armature 3. As a result, the pressurized fuel flows out of the injector 1 through the injection pipe 22. After flowing through the injection pipe 22, the fuel delivered by the injector 1 is then typically located outside the injector 1 in a combustion chamber. In addition, the fuel is usually compressed in the combustion chamber, where the fuel then ignites or is ignited.

The armature 3 (together with the valve needle 4) can be moved back and forth in the longitudinal direction of the injector 1. The movement of the armature 3, which can be formed in one piece or firmly connected to the valve needle 4, is controlled by a valve, which in the present illustration is the 1A a solenoid valve. The armature 3 is designed in such a way that it reacts to the magnetic force generated by a coil arrangement 17. The coil arrangement 17 can optionally have current flowing through it in such a way that the resulting magnetic force moves the armature 3 in the direction of the fuel inlet. This causes the armature 3 to move away from the valve plate 15. The resulting lifting of the valve needle 4 releases the throttle 5 in the valve plate 15 so that fuel can flow through the valve plate 15.

For precise guidance of the valve needle 4 along the longitudinal axis X of the injector 1 (hereinafter also referred to as the axial direction), a valve needle guide 19 can be provided which encloses an outer side of the valve needle 4 on the circumference. Since in the present embodiment the valve needle 4 is solid, at least one through-channel is provided in the valve needle guide 19 for the passage of fuel, through which fuel can flow to the fuel outlet. The valve needle guide is arranged firmly on the housing 2 of the injector 1.

Furthermore, an air gap 18 is provided between the armature 3 and the armature counterpart 7, which is closed or reduced when the coil 17 is energized.

In order to improve the magnetic flux 24 when the valve is implemented as a solenoid valve, the coil 17 can be surrounded on its outer peripheral side by an iron return 21, so that the magnetic field is particularly can spread well. The same applies to the housing component directly surrounding the armature element 3 and the armature counterpart 7, which preferably also consists of a magnetizable material. It can be advantageous if the pole tube, which is a component of the injector 1, is also made of iron or another ferromagnetic material. The same also applies to the armature counterpart 7, which advantageously also consists of a magnetizable material.

A visual representation of the magnetic field lines 24 is illustrated by the dotted, closed line that runs around the coil. The magnetic force pulls the armature 3 (together with the valve needle 4) towards the armature counterpart 7 and thus lifts it off the valve plate 15 or from the at least one throttle 5 that breaks through the valve plate 15, so that fuel flows into the injection pipe 23, from where the fuel can be introduced into the combustion chamber.

In order to guide the magnetic flux lines 24 preferably through the axial working air gap 18 between the armature 3 and the armature counterpart 7 and thus significantly increase the magnetic force between these components, it is advantageous to introduce a recess in the housing 2 at the level of the working air gap 18 or a non-magnetic or only weakly magnetizable one- or multi-part intermediate ring over the entire or partial thickness of the housing 2, e.g. by means of a welded connection. This is referred to below as a bypass 20. The bypass therefore ensures that the magnetic flux lines do not run through the housing 2 or only run through a very small part, where they have no effect on the attractive force between the armature element 3 and the armature counterpart 7.

The armature counterpart 7 is fixedly arranged in the longitudinal direction of the injector and has no play. The armature counterpart 7 is fixed between an adjusting element 8, which allows fine adjustment in the axial direction and can be disk-shaped, and the cover 12, whereby the adjusting element 8 is typically made of metal and serves to precisely specify the position of the armature counterpart 7 in relation to the longitudinal direction of the injector 1. During the manufacture of the injector 1, depending on the tolerances of the injector components, an adjusting element 19 selected accordingly can be installed so that the distance in the longitudinal direction of the injector from the armature 3 to the armature counterpart 7 corresponds to a predetermined value when the valve is in the closed position.

As described above, however, the problem arises that when the injector 1 is opened, the armature 3 collides with the armature counterpart 7 with high kinetic energy, resulting in bouncing. In particular, when using a gaseous fuel, the insulating effect of a fuel used in liquid form is lacking to reduce the bouncing of the armature 3 on the armature counterpart 7. The disadvantage of the bouncing process is that the closing process is not interrupted in a precisely predictable manner, but the bouncing causes the device to open and close several times.

1B shows the 1A shown injector in an open state for a comparison of a closed and an open injector valve. A fuel path through the injector 1 during fuel injection can be seen, shown by the arrows. In 1A the injector needle 4 is placed on the throttle 5 of the valve plate 15 in such a way that no fluidic connection can be established from the inlet of the injector 1 to the outlet. Only when the injector needle 4 is lifted, which occurs through the magnetic force induced in the armature 3 via the coil 17, is the throttle 5 opened and a fuel path through to the outlet created.

If a voltage signal is applied to the coil 17 of the actuator via electrical contacts by a control device, the current in the electrical circuit increases to a defined final level. The current-carrying coil 17 induces a magnetic field in the actuator, the magnetic field lines of which spread out in a toroidal shape around the coil 17. The magnetic field builds up a magnetic force in the (residual) air gap 18 between the armature 3 and the armature counterpart 7, whereby the armature 3 is attracted to the armature counterpart 7 as soon as the magnetic force exceeds the closing force (sum of the preload force of the needle spring 14 and the pressure forces on the needle 4 and the armature 3). The residual air gap is set using foils or shims.

The armature 3 is - as shown - advantageously fixedly connected to the valve needle 4 or is a one-piece armature-valve needle component, so that the valve needle 4 preferably moves uniformly with the armature 3. As soon as the valve needle 4 no longer closes the at least one throttle 5, the connection between the needle chamber and the injection chamber is released, so that the fuel flows from the needle chamber into the injection chamber and finally into the combustion chamber. When the armature 3 hits the upper stop, there is usually a relatively strong bounce, which has a negative effect on the controllability of the fuel injection quantity.

To end the blowing process, the power supply is stopped by a control unit so that the current through the coil 17 is reduced to zero. This also reduces the magnetic field. As soon as the magnetic force is low enough, the needle 4 and armature 3 begin to close preferably uniformly. If the front side of the needle 4 closes the at least one throttle 5 in the valve plate 15 again, the connection between the needle chamber and the injection chamber is severed and the fuel flow is interrupted and the fuel injection is terminated. Here too, bouncing behavior can occur, which has a negative effect on the controllability of the fuel injection quantity.

A large number of embodiments of the present invention are described below with reference to the accompanying figures. As a rule, specific features are described either for the pole core sleeve 9 or the armature sleeve 8, but it is clear to the person skilled in the art that the properties described can be present on both the pole core sleeve 9 and/or the armature sleeve 8. A separate description of the other sleeve is avoided for the sake of better clarity.

2 shows an injector 1 according to the invention in which a sleeve 8, 9 is provided both in the anchor element 3 and in the anchor counterpart 7.

It can be provided that one of the two sleeves 8, 9 protrudes from the component receiving it in the direction of the gap 18. In the present case, this is the pole core sleeve 9, which has a certain projection from the armature counter element 7 in the direction of the gap 18. Furthermore, the pole core sleeve 9 has a radially inward-directed recess at its end opposite the gap 18, which serves to provide the needle spring 14 with an attachment point 16. At the same time, the valve spring 14 can also be fixed and aligned by cleverly dimensioning the sleeve 9, this being done, for example, by a slightly thicker diameter of the pole core sleeve 9, which creates a certain clamping and guiding effect for the needle spring 14 and thus fixes it, for example, perpendicular to the axial direction.

In addition, 2 the armature element 3 is also provided with a sleeve, the armature sleeve 8, which, just like the pole core sleeve 9, is accommodated by a press fit or clearance fit in a recess in the component receiving the sleeve 8, 9 (armature element 3 or armature counterpart 7). In contrast to the pole core sleeve 9, the armature sleeve 8 in this case does not have an inwardly projecting recess, but has the basic shape of a cylindrical surface or a ring. The armature sleeve 8 and the pole core sleeve 9 are accommodated in their respective component (armature element 3 or armature counterpart 7) in such a way that their respective mutually facing end faces contact one another when the injector is opened and the armature 3 moves in the direction of the armature counterpart 7. The projection of the pole core sleeve 9 ensures that a defined residual air gap 18 remains and that the mutually facing end faces of the armature element 3 and armature counterpart 7 do not touch one another. As shown, the thickness and/or the outer diameter of the two sleeves 8, 9 can also be different, but advantageously, when the injector is open, the front surface of the protruding sleeve only touches the front surface of the other sleeve. In addition to the advantage of defining a predetermined residual air gap when the injector is open, a material pairing of the sleeves can also be selected that is designed for frequent collisions.

Thus, the armature sleeve 8 or the pole core sleeve 9 can consist of a magnetic or non-magnetic, hardened or high-strength steel or comprise such a steel.

The expert is aware that, although 2 only shows the variant according to which the pole core sleeve 9 has a projection, the invention also includes the fact that instead of the pole core sleeve 9 the armature sleeve 8 has a projection. The advantages described above can also be achieved with this.

3 shows a sectional view of the implementation according to the invention, in which both the armature sleeve 8 and the pole core sleeve 9 have a projection that each penetrates into the gap 18. When the injector is open, the residual air gap 18, i.e. the distance from the armature element 3 to the armature counterpart 7, is therefore no longer defined only by a projection 27 of one of the two sleeves 8, 9, but by the combined projection of the two sleeves (armature sleeve 8 and pole core sleeve 9). The exact axial position of the air gap 18 serves to influence the magnetic characteristic curve and therefore affects the opening and closing behavior of the injector 1.

4 shows a sectional view of a further embodiment of the present invention, in which the projection of the pole core sleeve 9 preferably protrudes so far from the armature counterpart 7 even in a closed state of the injector 1 that the latter is surrounded on the circumference by the armature element 3. In other words, the projection 27 of the pole core sleeve 9 engages in the armature element 3. For example, this can be done by designing the armature sleeve 8, which is somewhat wider in thickness, in such a way that it ends before reaching the gap 18. The gap thus left free The space available is taken up by the pole core sleeve 9 which overcomes the air gap 18.

5 shows a further development of the present invention, wherein the projection 27 of the pole core sleeve 9 is used for a guide 23 of the armature element 3. The inner diameter of the area that accommodates the projection 27 of the pole core sleeve 9 was adapted so that a guiding effect is generated when the armature 3 moves in the axial direction. The armature element is therefore guided not only by the needle guide 19, but also by the projection 27 of the pole core sleeve 9, so that jamming when the armature 3 moves is significantly less likely.

6 shows the above-described embodiment according to 5 , whereby this has been supplemented by a further damping function. It can be seen that the pole core sleeve 9 has an area with reduced thickness 26, which has a damping effect when an axially directed force is applied. If the armature element 3 is now moved from the closed to the open position, not only the needle spring 14 counteracts this movement, but also the pole core sleeve 9 itself. The reduction in thickness, which is partially or continuously formed in the circumferential direction, means that the sleeve can be compressed in the axial direction, so that the armature element 3 moving in the direction of the armature counterpart 7 is slowed down in its movement.

Viewed in the axial direction, both in front of and behind the region with the reduced thickness 26, the thickness of the material of the pole core sleeve 9 is normal again, i.e. increased compared to the region with the reduced thickness 26.

7 describes a further embodiment of the present invention, in which a non-magnetic and/or diamagnetic element 28 is arranged between the sleeve 9 and the armature counterpart 7 between the end region of a sleeve facing away from the air gap 18, in this case the pole core sleeve 9. This serves to interrupt or specifically redirect the magnetic flux that occurs when an active solenoid valve is activated. In conjunction with the bypass 20, this ensures that the magnetic flux is used effectively to generate the maximum magnetic force between the armature element 3 and the armature counterpart 7.

Furthermore, it can be provided that the element 28 is a soft elastic element and consists of or comprises an elastomer, an amorphous metal and/or a metallic glass, for example. As shown, the element 28 can have the shape of a disk, so that one could also speak of an insulating disk.

8 now shows an embodiment of the present invention in longitudinal section, in which both the armature sleeve 8 and the pole core sleeve 9 have a radially inwardly projecting recess for the support and guidance of the needle spring 14 at their end remote from the air gap 18. In addition, an adjusting disk 29 is also provided, which is arranged in the inner region of the armature sleeve 8 and is held in place in the axial direction by the recess. This adjusting disk 29 is used for fine adjustment of the tension of the needle spring 14, whereby the force urging the armature element 3 towards the closed position increases with increasing thickness of the adjusting disk 29. The reference number 16 designates the support and guidance of the needle spring 14, whereby this now occurs at both ends of the needle spring 14 due to the similar design of the armature sleeve 8 and pole core sleeve 9.

9A shows a further embodiment of the present invention, in which the mutually facing end faces of anchor element 3 and anchor counterpart 7 are not planar. The mutually facing end faces are still shaped to correspond to each other, but in the 9A However, there is a step arranged in the axial direction which serves to specifically influence the magnet characteristic. In addition, this step also creates a guide to enable the armature element 3 to move safely in the axial direction. The residual air gap 18 which remains between the two end faces when the injector 1 is in its open position is also created in this implementation by a projection of a sleeve, here the pole core sleeve 9.

9B shows in contrast to 9A the open position of the injector, whereby it can be clearly seen that the stop formed by the projection of the pole core sleeve 9 continues to form a residual air gap 18 of the mutually corresponding step-like end faces 30.

10 shows a further embodiment of the present invention, in which the sleeves provided with respective radially inwardly directed projections can also have a thickness reduction 26, which causes a certain damping effect when the anchor element 3 moves towards each other relative to the anchor counterpart 7.

11 shows a further embodiment of the injector 1 according to the invention in a sectional view view in which the pole core sleeve 9 in its outer peripheral area does not completely contact the component receiving it, in this case the armature counterpart 7. Rather, there is a radially extending gap 32 between the outer peripheral side of the pole core sleeve 9 and the armature counterpart 7 receiving the pole core sleeve 9. This radial gap 32 extends up to the air gap 18, but does not run over the entire axial length of the pole core sleeve 9. In the present example, the axial length of this gap 32 exceeds approximately half the total length of the pole core sleeve (seen in the axial direction).

Accordingly, it can be advantageous if the length of the gap 32 in the axial direction is at least half the length of the pole core sleeve 9 in the axial direction. This radial gap between the sleeve and the component receiving the sleeve (in 11 Armature counterpart 7) ensures that the magnetic field lines do not pass through the sleeve or only to a small extent.

12A shows a further embodiment of the present invention, in which the anchor element 3 is designed in several parts and has a lower anchor 33 and an upper anchor 34. The lower anchor 33 and the upper anchor 34 can be moved independently of one another in the axial direction. The anchor sleeve 8 has a radially outwardly projecting projection 35 at its end facing the gap 18, which corresponds to a corresponding recess in the upper anchor 34, so that when the upper anchor is moved, the projection 35 of the anchor sleeve 8 serves as a driver.

In the 12A In the closed position of the injector 1 shown, it can be seen that there is a gap in the axial direction between the upper armature 34 and the sleeve projection 35, which gap must only be overcome by a corresponding axial movement of the upper armature 34. When the coil 17 is energized, the upper armature 34 strikes the collar of the sleeve projection 35 of the armature sleeve 8 after overcoming the gap and thus reduces the magnetic force required to open the valve due to the kinetic energy it absorbs during the start-up movement.

This principle is also called a hammer armature, since the upper armature strikes the sleeve projection 35 like a hammer and, via the connection of the armature sleeve 8 with the lower armature 33, jerks the needle 4 away from the throttle 5. An armature return spring 36 is also provided to push the upper armature 34 back, which serves to push the upper armature 34 in the direction of the throttle 5 so that, when the injector 1 is closed, a pronounced gap in the axial direction is again established between the upper armature 34 and the sleeve projection 35.

12B shows an open state of the injector 1, which is already in 12A described. It can now be seen that the valve needle 4 has been lifted off the throttle 5, so that fuel can flow out of the injector 1. The lifting of the valve needle 4 connected to the lower armature 33 was caused by the upper armature 34 engaging the sleeve projection 35 of the armature sleeve 8. The previously existing air gap 37 between the upper armature 34 and the sleeve projection 35 is now closed. The armature return spring 36 is in a compressed state and, after the magnetic force which pushes the upper armature towards the armature counterpart 7 has subsided, causes the upper armature 34 to be pushed towards the lower armature 33 until it contacts it and then pushes it further towards the throttle 5. This ultimately leads to the throttle 5 closing and the fuel flow being interrupted.

13 shows a further embodiment of the present invention, in which the pole core sleeve 9 is a movable sleeve 39 that can be moved back and forth in the axial direction. The pressing of the armature element 3 against the throttle 5 in a closed state of the injector 1 therefore does not take place exclusively by the force applied by the needle spring 14, but is supported by the movable pole core sleeve 39 which is pushed in the direction of the armature element 3 by means of the sleeve spring 38. The movable sleeve 39 can also be referred to as a sliding sleeve and completely overcomes the air gap 18 between the armature element 3 and the armature counterpart 7, which forms when the injector 1 is closed. At the end of the movable sleeve 39 facing away from the anchor element 3, the anchor counterpart has a stop 40 which ensures that when the injector 1 is opened, the air gap 18 present between the anchor element 3 and the anchor counterpart 7 is not completely closed, but remains in a reduced form due to a remaining projection of the sleeve part of the movable sleeve 39 protruding from the anchor counterpart 7.

This ensures that when the injector is open, the anchor element 3 and the anchor counterpart 7 do not rest against each other on the surfaces facing each other, since a projection of the movable sleeve 39 remains by means of the stop 40. The stop 40 can be finely adjusted in its axial position by inserting an adjusting disk 29 in order to maintain the compressed spring from the anchor counterpart 7 to precisely adjust the protrusion of the movable sleeve 39.

14 shows a further training of the 13 described embodiment of the injector 1, wherein the anchor counterpart 7 is formed in several parts.

Thus, the part that serves for attaching the movable sleeve 39 can be designed separately from another part of the armature counterpart 7. This section, identified by the reference numeral 41, can represent a fixed secondary sleeve, which in conjunction with the other part of the armature counterpart 7 forms a receptacle for the adjusting disk 29 and the sleeve spring 38.

List of reference symbols:

1

injector

2

injector housing

3

anchor element / anchor

4

valve needle

5

throttle

6

interference or clearance fit

7

anchor counterpart

8

anchor sleeve

9

pole core sleeve

10

adjusting/stop disc needle spring

11

adjusting/stop disc needle spring

12

lid

13

adjustment element

14

needle spring

15

valve plate

16

bearing / guidance of the needle spring

17

Sink

18

air gap

19

needle guide

20

bypass element

21

iron return / housing section

22

injection pipe

23

upper anchor and needle guide

24

course of magnetic field lines

25

guide element

26

thickness reduction for damper function

27

sleeve overhang

28

non-magnetic or diamagnetic element

29

adjustment disc

30

step-like front surface

31

stop

32

radial gap

33

lower anchor

34

upper anchor

35

sleeve projection

36

armature return spring

37

air gap anchor - sleeve projection

38

sleeve spring

39

movable sleeve

40

case stop

41

fixed secondary sleeve

X

axial direction of the injector

Claims (15)

Injector for injecting fuel, preferably for blowing in a gaseous fuel, in particular hydrogen, comprising: an injector housing for receiving and arranging injector components, an anchor element which is arranged in the injector housing so as to be movable along an axial direction of the injector and is designed to close or release a throttle by an axial movement along the injector housing in order to allow fuel to flow through this throttle, a valve, in particular a solenoid valve, which is designed to transfer the anchor element from a closing to a releasing state of the throttle and vice versa, and an anchor counterpart which is arranged on the side of the anchor element opposite the throttle, wherein in a state of the anchor element closing the throttle, a gap running in the axial direction is formed between the anchor counterpart and the anchor element, both the anchor element and the anchor counterpart have a through-channel running in the axial direction for conducting fuel, and a spring element arranged in the through-channel of the anchor element and in the through-channel of the anchor counterpart is provided to force the armature counterpart and the armature element apart and to move the armature element into a state closing the throttle, characterized in that a sleeve, the so-called anchor sleeve, is arranged in the through-channel of the anchor element and/or a sleeve, the so-called pole core sleeve, is arranged in the through-channel of the anchor counterpart, wherein the at least one sleeve is arranged in its through-channel such that it protrudes in the axial direction relative to the component receiving it and projects into the gap. Injector according to the preceding claim, wherein the at least one sleeve has an inwardly projecting projection at its end remote from the gap in order to enable the spring element to be attached there. Injector according to one of the preceding claims, wherein the at least one sleeve has at least partially an inner diameter in order to guide and align the spring element, preferably a spiral spring. Injector according to one of the preceding claims, wherein the at least one sleeve has a section in the axial direction which has a reduced wall thickness, so that damping occurs when an axial force compressing the sleeve acts. Injector according to one of the preceding claims, wherein the at least one sleeve is fixedly arranged in the component receiving it. Injector according to one of the preceding Claims 1 - 4 , wherein the at least one sleeve is arranged so as to be movable in the axial direction in the component receiving it, wherein a sleeve spring is preferably arranged at an end of the sleeve remote from the gap in order to urge the sleeve towards the gap. Injector according to one of the preceding claims, wherein the sleeve protrudes so far from the component receiving it that it penetrates into the through-channel of the other component provided with the through-channel, preferably in order to provide guidance during a movement of the armature in the axial direction, wherein the outer diameter of the section of the sleeve protruding into the other component is preferably matched to the inner diameter of the through-channel of the other component in order to allow a sliding movement of the other component relative to the penetrating sleeve section. Injector according to one of the preceding claims, wherein a non-magnetic or diamagnetic element is arranged between the end of the sleeve facing away from the gap and the component receiving the sleeve in order to interrupt or specifically redirect a magnetic flux, wherein the non-magnetic or diamagnetic element is a soft elastic element, for example an elastomer, an amorphous metal and/or a metallic glass. Injector according to one of the preceding claims, wherein the mutually facing end faces of the anchor element and the anchor counterpart have a design corresponding to one another, but are not smooth, wherein preferably the end face of the anchor element and the anchor counterpart have a step rising in the axial direction. Injector according to one of the preceding claims, wherein the outer circumference of the at least one sleeve has a radial gap extending in the axial direction to the component receiving it in order to reduce or completely prevent a flow of magnetic field lines through the sleeve, preferably wherein the radial gap extends in the axial direction from the end facing the gap. Injector according to one of the preceding claims, wherein a sleeve, the so-called anchor sleeve, is arranged both in the through-channel of the anchor element and a sleeve, the so-called pole core sleeve, is arranged in the through-channel of the anchor counterpart, wherein each of the two sleeves protrudes from the respective component receiving it in the direction of the gap. Injector according to one of the preceding claims, wherein, when an anchor sleeve and a pole core sleeve are present, the two sleeves are arranged relative to one another in their respective through-channel such that the mutually facing end faces of the two sleeves contact one another when the injector is in an open state. Injector according to one of the preceding claims, wherein, when an anchor sleeve and a pole core sleeve are present, the outer diameter of the two sleeves is the same or different. Injector according to one of the preceding claims, wherein the anchor element is designed in several parts and has a lower part facing the throttle and an upper part arranged between the lower part and the anchor counterpart, the upper part is movable in the axial direction relative to a sleeve inserted into the lower part, the sleeve protrudes from the lower part in a closed state viewed in the axial direction and projects beyond the upper part of the multi-part anchor element, and the sleeve has a radial projection on the side facing away from the throttle, which corresponds to a corresponding recess of the upper part of the anchor element, so that when the upper part is moved in the direction of the anchor counterpart, the sleeve and the lower part of the anchor element connected thereto are moved in the direction of the anchor counterpart according to the principle of a hammer anchor, wherein preferably an anchor spring is provided which is designed to urge the upper part of the anchor element in the direction of the throttle. Internal combustion engine with a fuel injection, in particular with a gas direct injection, in particular with a hydrogen direct injection, comprising an injector according to one of the preceding claims.

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