Injector for injecting fuel

Abstract

The present invention relates to an injector for injecting fuel, preferably for injecting a gaseous fuel, in particular hydrogen, comprising: an injector housing (2) for receiving and arranging injector components;an armature element (3, 4) which is arranged in the injector housing (2) so as to be movable in an axial direction of the injector (1) and is designed to close or open up a throttle (5) by means of an axial movement along the injector housing (2) in order to allow or prevent a fuel flow (25) through said throttle (5);a magnet coil (6) which is designed to transfer the armature element (3, 4) from a state in which it closes the throttle (5) into a state in which it opens up same;a pole core (7) which is arranged fixedly relative to the injector housing (2) on the opposite side of the armature element (3, 4) to the throttle (5) and which serves to conduct magnetic field lines (23) generated by the magnet coil (6);a spring element (8) which is arranged between the armature element (3, 4) and the pole core (7) and which is designed to force the armature element (3, 4) in the direction of the throttle (5);an armature sleeve (9) and a pole core sleeve (10) which are designed such that, when the armature element (3, 4) has been lifted off from the throttle (5) to a maximum extent, said armature sleeve and pole core sleeve form mutual stop surfaces and define a residual air gap (24) between the armature element (3, 4) and the pole core (7); and at least one damping element (13) situated on the pole core (7) and projecting in the axial direction beyond the pole core sleeve (10), and / or at least one damping element (13) situated on the armature element (3) and projecting in the axial direction beyond the armature sleeve (9), in order to dampen an impact of the armature sleeve (9) and the pole core sleeve (10).

Description

[0001] Injector for injecting fuel

[0002] The present invention relates to an injector for injecting fuel, in particular for injecting a gas, preferably for directly injecting hydrogen. The injector may be designed to inject fuel into a combustion chamber of an internal combustion engine.

[0003] With increasingly stringent emissions limits worldwide and ambitious climate protection goals, the environmental requirements for internal combustion engines are constantly rising. The aim in the foreseeable future is 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 combustion-based technologies, these goals are only achievable with the use of climate-neutral, regeneratively produced fuels that cause no emissions whatsoever along the entire value chain (so-called "zero-emission" fuels).

[0004] With current conventional gasoline, diesel, and gas engines, the requirements for emission-free combustion – even with the use of so-called e-fuels, e.g., a synthetically produced OME fuel, for the production of which only renewable energy is required – are not achievable, as the emission of harmful exhaust gases such as nitrogen oxides (NOx) X ), unburned hydrocarbons (UHC) and soot cannot be completely reduced with current technologies.

[0005] In principle, battery-powered drives comply with the zero-emissions directive during operation and are gaining ground, particularly in the passenger car sector. However, when the entire value chain is considered, the production of (lithium) batteries is very energy-intensive and problematic from an environmental perspective, as significant environmental damage occurs during raw material extraction, and the extraction of the raw materials required for the batteries is not sustainable. Furthermore, the current power-to-weight ratio of batteries does not allow for their use in machines with high (peak) power demands.

[0006] Fuel cell-powered drives supplied with regeneratively produced hydrogen meet the prescribed climate protection targets and are already in use today, albeit to a very limited extent. However, this concept also has some disadvantages, such as lower peak power and lower economic efficiency compared to current diesel drives.

[0007] Hydrogen combustion engines, which represent a promising alternative drive system, have therefore moved into focus. However, to date, these exist almost exclusively in very small numbers or as demonstrators with a low level of development. Hydrogen produced using renewable energy would meet all the requirements of "zero emission," as it can be combusted without producing emissions.

[0008] In passenger cars, for example, hydrogen engines with port fuel injection (PFI) are used, in which the fuel is thoroughly mixed with air for a sufficient amount of time before entering the combustion chamber. Hydrogen engines with direct injection of the fuel into the combustion chamber (direct injection, DI) play practically no role today, but compared to the PFI concept, they offer, among other things, higher efficiency, more stable combustion, and the elimination of the risk of backfire into the intake manifold.

[0009] In direct-injection hydrogen engines, a distinction is typically made regarding the maximum injection pressure in the injector (< 60 bar: low pressure, > 60 bar: high pressure), although the boundaries are not clearly defined and the transitions are gradual. Higher pressures offer the potential for a shorter injection duration in a later phase of compression at higher combustion chamber pressures, resulting in increased efficiency and improved combustion stability. However, overall efficiency decreases if prior compression of the hydrogen is necessary.

[0010] However, the development of injectors for injecting fuel, especially gaseous fuel, has revealed several challenges. Among others, the following points have proven problematic:

[0011] • Increased risk of wear on guides of moving components due to the practically non-existent lubricating effect of gaseous fuels, especially hydrogen

[0012] • Significantly greater tendency of moving components to bounce against mechanical stops in gas injectors compared to injectors with liquid fuels due to low damping effect during gas compression

[0013] The aim of the present invention is to at least partially overcome or mitigate the aforementioned disadvantages. In particular, it aims to address the problem of the significantly greater wear between the reciprocating parts and the problem of pronounced bouncing, which occurs in gas injectors compared to injectors using liquid fuels. Liquid fuels inherently have a damping or lubricating effect, so that an element surrounded by the fuel is already dampened in its movement and experiences less wear when sliding along another element.

[0014] The present invention succeeds in solving or mitigating at least one of the problems mentioned above. For this purpose, an injector is provided which has all the features of independent claim 1. Advantageous embodiments of the present invention are found in the dependent claims that follow thereto.

[0015] The invention describes an injector for injecting fuel, preferably for injecting a gaseous fuel, in particular hydrogen, and comprises an injector housing for receiving and arranging injector components, an armature element which is movably arranged in the injector housing along an axial direction of the injector and is designed to close or release a throttle by means of an axial movement along the injector housing in order to enable or prevent fuel flow through this throttle, a magnetic coil which is designed to transfer the armature element from a closing to a releasing state of the throttle, a pole piece which is fixedly arranged opposite the injector housing on the side of the armature element opposite the throttle and which serves to guide magnetic field lines generated by the magnetic coil, a spring element,which is arranged between the armature element and the pole piece and is designed to push the armature element towards the throttle; an armature sleeve and a pole piece sleeve which, when the armature element is raised to its maximum extent from the throttle, are designed to form mutual contact surfaces and define a residual air gap between the armature element and the pole piece; and at least one damping element on the pole piece that projects axially beyond the pole piece sleeve, and / or at least one damping element on the armature element that projects axially beyond the armature sleeve to dampen contact between the armature sleeve and the pole piece sleeve. Providing the damping element between the pole piece and the armature element increases the service life of the injector and improves the metering efficiency when delivering minute quantities of fuel. This is achieved by…The damping element selectively dissipates and dissipates the impact energy when the armature element is lifted from a closed position and strikes the pole piece sleeve, thus significantly reducing or even completely preventing the undesirable bouncing effect. The smoother opening movement produced by damping the bouncing allows a more predictable amount of fuel to escape through the throttle towards the injector's discharge port, making metering, especially when dispensing very small quantities of fuel, more reliable.

[0016] The pole core is rigidly connected to the pole core sleeve, and the armature element is rigidly connected to the armature sleeve. The armature sleeve may be designed to project axially beyond the armature element on the side facing the pole core. Similarly, the pole core sleeve may be designed to project axially beyond the pole core on the side facing the armature element. Furthermore, it may be designed so that, during axial movement of the armature element towards the pole core, the movement is limited by the armature sleeve abutting the pole core sleeve. The armature element remains spaced from the pole core; this space is referred to as the residual air gap.

[0017] According to an optional modification of the present invention, it can be provided that the magnetic coil is designed in a ring shape and surrounds the armature element circumferentially, preferably wherein the ring-shaped magnetic coil also surrounds the pole core circumferentially.

[0018] The ring-shaped design of the magnetic coil, which moves the armature element away from the throttle, allows for particularly efficient use of the generated force. Furthermore, the armature element is (partially) located within the ring-shaped magnetic coil, so that the magnetic force generated by the coil, in conjunction with the pole core, lifts the armature element from the throttle plate with exceptional efficiency. Another advantage is that the ring-shaped design of the magnetic coil allows for a particularly large cross-section for conducting fuel, which is beneficial for gaseous fuels, especially hydrogen, since gaseous hydrogen has a significantly lower energy density than previously used liquid fuels.As a result, the ring-shaped magnetic coil also contributes to a larger cross-sectional area for the passage of gaseous fuel through the injector.

[0019] According to an advantageous embodiment of the present invention, it can be provided that the anchor element for conveying fuel is designed to be hollow, preferably hollow over its entire length in the axial direction.

[0020] Furthermore, it may be provided that the pole core is also hollow, so that a conduit for fuel can be formed through the hollow section of the pole core and the armature element to the throttle plate.

[0021] The hollow design of the armature element and / or pole core simplifies the flow of gaseous fuel from an inlet opening into the injector to an outlet opening of the injector with the largest possible cross-sectional area. Furthermore, the hollow design of the armature element and / or pole core also allows for a symmetrical cross-sectional design of the various components, enabling simple and cost-effective manufacturing.

[0022] According to a further optional modification of the present invention, the damping element may comprise or consist of a synthetic carbon-based polymer, preferably with at least one additive added to improve the damping properties or abrasion resistance. Suitable additives include, for example, plasticizers such as phthalates, adipates, and sebacates; fillers such as carbon fibers, glass fibers, or silicon dioxide; a hardener such as carbon black; the lubricant PTFE; or nanomaterials such as nanoclay or graphene. Alternatively and / or additionally, the damping element may comprise or be made of a metal foam.

[0023] A metal foam is a porous material consisting of a metal matrix with a sponge-like structure. This structure is created by the incorporation of gas bubbles during the manufacturing process, resulting in high porosity. Metal foam can be made from various metals such as aluminum, titanium, nickel, or copper and is capable of absorbing large amounts of impact energy.

[0024] According to a further advantageous modification of the present invention, it can be provided that the at least one damping element is arranged on an end face of the pole core and / or the anchor element.

[0025] The at least one damping element can be arranged on the pole core, the armature element, or both components of the injector. Its purpose is to reduce or prevent bouncing against the stop sleeves when the armature element moves towards the pole core. This is achieved by compressing or deforming the damping element, thus slowing down the armature element as it moves towards the pole core and mitigating any bouncing. Even when the armature element is fully extended and the two stop sleeves are in contact, a residual air gap remains between the armature element and the pole core. This prevents direct contact between the two components, thus preventing unwanted magnetization of the armature element.The pole core is advantageous because direct contact between the armature element and the pole core hinders precise control over a longer period of time.

[0026] Furthermore, it can be provided that the at least one damping element is arranged on a plane of the pole core and / or on a plane of the anchor element. This plane can be perpendicular to the axial direction of the injector, so that the normal direction of the plane is parallel to the axial direction.

[0027] Advantageously, it can be provided that several damping elements are arranged on a circular surface, which are preferably aligned at the same angle to each other.

[0028] If several separate damping elements are present, they can, for example, be designed as points or similar and spaced at equal angles to each other along an annulus. However, it is also conceivable that at least one damping element extends elongated along the annulus.

[0029] According to a further advantageous modification of the present invention, it can be provided that a hard material layer, in particular a titanium-based layer (e.g. TiN, TiAIN, TiCN or TiAISiCN), a hard chrome layer or a DLC layer, is provided on the inside of the injector housing and / or on the outside of the anchor element to guide the anchor element relative to the injector housing, in order to enable a low-friction sliding contact.

[0030] A DLC (Diamond-Like Carbon) layer, i.e., a thin coating of amorphous carbon, possesses properties similar to those of diamond.

[0031] According to a further advantageous embodiment of the present invention, it can be provided that the anchor element is guided in a bearing bushing opposite the injector housing, which is connected to the injector housing by friction or form locking.

[0032] The bearing sleeve can be hollow and have a circumferential projection at at least one of its axial ends, which simplifies its placement in the correct position within the injector. Furthermore, the bearing sleeve can be designed with a multi-layered structure to provide, on the one hand, a specific material pairing for connection to the injector housing and, on the other hand, a specific material pairing for tribological contact with the anchor element. The respective material pairings can be adapted to the different requirements for fastening to the injector housing and for the sliding frictional movement with the anchor element, which moves back and forth within the bearing sleeve.

[0033] Advantageously, the bearing bushing may comprise or consist of a synthetic carbon-based polymer, preferably with at least one PTFE-based, PEEK-based, or polyimide-based additive. PEEK (polyetheretherketone) is a high-performance thermoplastic polymer that possesses high mechanical strength and high temperature resistance.

[0034] Furthermore, the bearing bushing can be designed with glass fibers as a filler. This increases mechanical strength and abrasion resistance, thus extending the service life of the glass fiber-reinforced bearing bushing.

[0035] Furthermore, according to the present invention, it can be provided that a hard material layer, in particular a titanium-based layer, a hard chrome layer or a DLC layer, is provided on the guide surface of the anchor element facing the bearing bushing, which is in contact with the surface of the bearing bushing facing the anchor element.

[0036] According to a further development of the invention, the injector can be designed to inject fuel, in particular hydrogen, into a combustion chamber of an internal combustion engine. The invention further relates to an internal combustion engine with fuel injection, in particular with direct gas injection, and especially with direct hydrogen injection, comprising an injector according to one of the aspects discussed above.

[0037] Further features, details, and advantages of the invention will become apparent from the following description of the figures. These show:

[0038] Fig. 1 : a schematic sectional view of an injector according to the invention in a closed state,

[0039] Fig. 2: an enlarged view of a specific part of Fig. 1, showing the area of ​​the stop surface of the pole piece sleeve and the armature sleeve,

[0040] Fig. 3: an enlarged view of a specific part of Fig. 1, showing the layer structure of the bearing bushing,

[0041] Fig. 4: an enlarged view of a specific part of Fig. 1, showing the placement of the armature element on the throttle,

[0042] Fig. 5: a cross-sectional view of the injector along section B -- B from Fig. 1 ,

[0043] Fig. 6: a schematic sectional view of an injector according to the invention in an open state,

[0044] Fig. 7: an enlarged view of a specific part of Fig. 6, showing the layer structure of the bearing bushing,

[0045] Fig. 8: an enlarged view of a specific part of Fig. 6, showing the area of ​​the stop surface of the pole piece sleeve and armature sleeve in the lifted state, and Fig. 9: an enlarged view of a specific part of Fig. 6, showing the lifting of the armature element from the choke.

[0046] The following detailed description of the figures is explained using an injector for injecting a gaseous fuel, but it is clear to those skilled in the art that the invention also includes an injector for injecting another fuel, e.g. liquid fuel.

[0047] Fig. 1 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 in which various components of the injector 1 are located. On the connection side, a connection element 11 is provided for a fuel supply line for introducing fuel into the injector 1. First, the fuel or another combustible fluid (for example hydrogen) is guided through a fuel passage running approximately centrally in the injector housing 2 to the end of the armature element 3, 4 furthest from the connection side. The armature element 3, 4 can comprise a valve element 4 and an armature 3, whereby it is known to those skilled in the art that the armature element 3, 4 can be designed as a single piece or in multiple parts.

[0048] 4 and anchor 3 are preferably firmly connected to each other, e.g. by frictional connection.

[0049] Depending on the position of the armature 3 or the valve element 4 relative to the throttle 5, the at least one throttle 5 penetrating the throttle plate 26 is either closed or opened. In the state shown in Fig. 1, the throttles 5 are closed by the pressure of the valve needle 4 against the valve plate 26, since the end face of the valve element 4 defines the opening contours of the throttles.

[0050] covers 5.

[0051] If the throttles 5 are closed by the front face of the valve element 4, the fluid flow of the fuel at this point of the injector 1 is stopped and there is no downward flow of fuel beyond the throttle plate 26.

[0052] If, however, the throttles 5 are released, which is achieved by the armature 3 lifting away from the throttle plate 26 and the resulting lifting of the valve element 4, the fuel introduced into the injector 1 at a certain pressure flows out and exits via the multiple throttles 5 on the side of the throttle plate 26 spaced away from the armature 3. Consequently, the pressurized fuel flows out of the injector 1. After the fuel has been dispensed, it is typically located outside the injector 1 in a combustion chamber. Furthermore, the fuel is typically compressed in this combustion chamber, where it then ignites.

[0053] The armature 3 (together with the valve element 4) is movable back and forth in the longitudinal direction of the injector 1. The movement of the armature 3, which can be formed integrally with or rigidly connected to the valve element 4, is controlled by a solenoid coil 6. The armature element 3, 4 is designed to react to the magnetic force generated by the solenoid coil 6. The solenoid coil 6 can optionally be energized such that the resulting magnetic force moves the armature element 3, 4 towards the fuel inlet. This causes the armature element 3, 4 to move away from the throttle plate 26, which has at least one throttle 5, in the opposite direction to the force exerted on the armature element 3, 4 by the spring element 8. The resulting lifting of the valve element 4 releases the at least one throttle 5 in the throttle plate 26, allowing fuel to flow through the throttle plate 26.

[0054] For precise guidance of the armature element 3, 4 in the axial direction of the injector 1, a bearing bushing 17 can be provided, which is arranged on the injector housing 2 and circumferentially surrounds an outer surface of the valve needle 4 or the armature 3. An air gap 24 is provided between the armature element 3, 4 and the pole core 7, which is reduced when the solenoid coil 6 is energized. Preferably, the residual air gap is never completely closed due to the armature sleeve and the pole core sleeve.

[0055] To improve the magnetic flux 23, the pole core 7 can be made of a magnetizable material. It can therefore be advantageous if the pole core 7 is made of iron or another ferromagnetic material.

[0056] A visual representation of the magnetic field lines 23 is illustrated by the dotted, closed line that runs through the magnetic coil 6. The magnetic force pulls the armature 3 (together with the valve element 4) towards the pole piece 7 and thus lifts it away from the throttle plate 26 or from the throttles 5 that penetrate the throttle plate 26, causing fuel to flow out of the injector 1.

[0057] To prevent the armature 3 from colliding with the pole piece 7 with high kinetic energy during the opening process of the injector 1, resulting in a bouncing action, a damping element 13 is provided.

[0058] The pole core sleeve 10 is surrounded radially outwards by the pole core 7, and the anchor sleeve 9 is surrounded radially outwards by the anchor element 3, 4. The pole core sleeve 10 and the anchor sleeve 9 are the components that contact each other when the anchor element 3, 4 is fully extended. The anchor element 3, 4 and the pole core 7 remain spaced apart and do not directly touch each other.

[0059] Both the armature sleeve 9 and the pole piece sleeve 10 can have an inwardly directed projection at their respective ends spaced apart from the other sleeve 9, 10. This projection serves to attach the spring element, e.g., in the form of a coil spring. This ensures that the armature element 3, 4, which interacts with the armature sleeve 9, is forced by the pole piece 7 towards the throttle plate 26 by the spring force of the spring element 8.

[0060] Fig. 2 shows an enlarged section of Fig. 1 in the area of ​​the stop surface of the pole piece sleeve 9 and anchor sleeve 10.

[0061] The damping element 13 can be seen, which can be inserted into the pole core 7 and projects axially beyond the pole core sleeve 10 towards the armature 3. The pole core sleeve 10 projects axially beyond the pole core 7 by half a residual air gap 15. The same applies to the armature sleeve 9, which also projects axially beyond the armature 3 by half a residual air gap 15. In a closed state of the injector 1, the distance between the armature sleeve 9 and the pole core sleeve 10 is the maximum stroke 14 that the armature element 3, 4 can execute.

[0062] Fig. 3 shows an enlarged section of Fig. 1 in the area of ​​the layer structure of the bearing bushing 17.

[0063] Reference numeral 16 designates the guide surface of the armature 3, which is in frictional contact with the inner surface of the bearing bushing 17 facing the armature 3. It can be seen that the bearing bushing 17 can, for example, have a three-layer structure, whereby the first layer, facing the armature 3, is not directly connected to the third layer, which is connected to the injector housing 2, but rather an intermediate layer exists that connects the two outer layers of the bearing bushing 17.

[0064] Fig. 4 shows an enlarged view from Fig. 1 in the area of ​​the throttle 5 of the throttle plate 26.

[0065] A sealing element 19 can be provided on the side of the valve member 4 facing the throttle plate 26, sealing the opening contour of the throttle 5 of the throttle plate 26. To enhance the sealing function, a sealing lip 20 can be provided, which covers the opening contour of the throttle 5. Fig. 5 is a cross-section of the injector 1 along section B -- B from Fig. 1. It can be seen that the line for conveying the fuel through the injector 1 is arranged approximately centrally, and the other injector components are arranged around it. The spring element 8, which is supported by the inwardly projecting extension of the pole piece sleeve 10, is visible. Furthermore, the injector housing 2 and the annular solenoid coil 6, arranged externally opposite the injector housing 2, are also visible.

[0066] Fig. 6 shows a schematic sectional view of an injector 1 according to the invention in an open state.

[0067] The fuel mass flow 25 flowing through injector 1 is schematically represented by dashed arrows. This flow passes from the connection element 11 through the hollow pole piece 7, the hollow armature element 3, 4, the throttle 5 and then exits injector 1.

[0068] Fig. 7 shows an enlarged view of Fig. 6, which illustrates the layer structure of the bearing bushing. The layer structure is identical to that shown in Fig. 3.

[0069] Fig. 8 shows the area of ​​the contact surface of the pole core sleeve 10 and the armature sleeve 9 in the extended state of the armature element 3, 4, so that it is immediately apparent how the pole core sleeve 10 and the armature sleeve 9 contact each other. Further extension of the armature element 3, 4 away from the throttle plate 26 is therefore not possible. To prevent rebound when the two contact surfaces strike each other, the damping element 13 is provided, which is deformed when the armature 3 is moved towards the pole core 7 (the deformation of the damping element 13 is not shown in Figure 8).

[0070] Fig. 9 shows an enlarged view from Fig. 6, illustrating the lifting of the armature element 3, 4 from the throttle plate 26. Since the armature sleeve 9 abuts the pole core sleeve 10, the armature element 3, 4 is lifted maximally from the throttle plate 26, so that the gap between the throttle plate 26 and the valve element 4 exhibits the maximum stroke 14. The lifting of the sealing element 19 from the throttle 5 causes fuel to flow out of the injector 1.

[0071]

[0072] 1 injector

[0073] 2 injector housings

[0074] 3 anchors; part of the anchor element

[0075] 4 Valve element, part of the anchor element

[0076] 5 Throttle

[0077] 6 magnetic coil

[0078] 7 pole core

[0079] 8 spring element

[0080] 9 Anchor sleeve

[0081] 10 Pole piece sleeve

[0082] 11 Connection element

[0083] 12 Stop surface of the pole piece sleeve

[0084] 13 Damping element

[0085] 14 maximum stroke

[0086] 15 half residual air gap

[0087] 16 Guide surface of the anchor

[0088] 17 storage box

[0089] 18 Layer structure of the bearing bushing

[0090] 19 Sealing element

[0091] 20 sealing lip

[0092] 21 Sealing cross-section

[0093] 22 Stop surface of the throttle

[0094] 23 Magnetic field line

[0095] 24 total residual air gap

[0096] 25 Fuel mass flow

[0097] 26 Throttle plate A / valve plate

Claims

Injector for injecting fuel Claims 1. Injector (1) for injecting fuel, preferably for injecting a gaseous fuel, in particular hydrogen, comprising: an injector housing (2) for receiving and arranging injector components, an armature element (3, 4) which is movably arranged in the injector housing (2) along an axial direction of the injector (1) and is designed to close or release a throttle (5) by means of an axial movement along the injector housing (2) in order to enable or prevent a fuel flow (25) through this throttle (5), a magnetic coil (6) which is designed to transfer the armature element (3, 4) from a closing to a releasing state of the throttle (5), a pole piece (7) which is fixedly arranged opposite the injector housing (2) on the side of the armature element (3, 4) opposite the throttle (5) and serves to guide magnetic field lines (23) generated by the magnetic coil (6), a spring element (8),which is arranged between the armature element (3, 4) and the pole core (7) and is designed to push the armature element (3, 4) towards the throttle (5), an armature sleeve (9) and a pole core sleeve (10) which, when the armature element (3, 4) is maximally lifted from the throttle (5), are designed to form mutual stop surfaces and to define a residual air gap (24) between the armature element (3, 4) and the pole core (7), and, at least one damping element (13) on the pole core (7) which extends axially beyond the pole core sleeve (10), and / or at least one damping element (13) on the anchor element (3) which extends axially beyond the anchor sleeve (9) in order to dampen impacts between the anchor sleeve (9) and the pole core sleeve (10).

2. Injector (1) according to the preceding claim, wherein the magnetic coil (6) is designed in an annular shape and surrounds the armature element (3, 4) circumferentially, preferably wherein the annularly designed magnetic coil (6) also surrounds the pole core (7) circumferentially.

3. Injector (1) according to one of the preceding claims, wherein the anchor element (3, 4) is designed to be hollow for conveying fuel (25), preferably being designed to be hollow over its entire length in the axial direction.

4. Injector (1) according to any of the preceding claims, wherein the damping element (13) comprises or consists of a synthetic carbon-based polymer, preferably including at least one additive to improve the damping properties or the abrasion resistance.

5. Injector (1) according to any one of the preceding claims 1-3, wherein the damping element (13) comprises or is made of a metal foam.

6. Injector (1 ) according to one of the preceding claims, wherein the at least one damping element (13) is arranged on an end face of the pole core (7) and / or the anchor element (3, 4).

7. Injector (1) according to the preceding claim 6, wherein the at least one damping element (13) is arranged on a plane of the pole core (7) and / or on a plane of the anchor element (3, 4).

8. Injector (1 ) according to one of the preceding claims 6 or 7, wherein several damping elements (13) are arranged on a circular surface, which are preferably arranged at equal angles to each other.

9. Injector (1) according to one of the preceding claims, wherein a hard material layer, in particular a titanium-based layer, a hard chrome layer or a DLC layer, is provided on the inside of the injector housing (2) and / or on the outside of the anchor element (3, 4) to guide the anchor element (3, 4) relative to the injector housing (2) in order to enable a low-friction sliding contact.

10. Injector (1 ) according to one of the preceding claims, wherein the anchor element (3, 4) is guided relative to the injector housing (2) in a bearing bushing (17) which is connected to the injector housing (2) by friction or form locking.

11. Injector (1 ) according to the preceding claim 10, wherein the bearing bushing (17) has a multi-layered structure (18) to provide, on the one hand, a specific material pairing for connection with the injector housing (2) and, on the other hand, a specific material pairing for tribiological contact with the anchor element (3, 4).

12. Injector (1) according to one of the preceding claims 10 or 11, wherein the bearing bushing (17) comprises or consists of a synthetic carbon-based polymer, preferably wherein at least one PTFE-based, PEEK-based or polyimide-based additive is added.

13. Injector (1 ) according to the preceding claim 12, wherein the bearing bushing (17) is filled with glass fibers.

14. Injector (1) according to one of the preceding claims 10-13, wherein a guide surface of the anchor element (3, 4) facing the bearing bushing (17) is provided A hard coating, in particular a titanium-based coating, a hard chrome coating, or a DLC coating, is provided, which is in contact with the surface of the bearing bushing (17) facing the anchor element (3, 4).

15. Internal combustion engine with fuel injection, in particular with a Gas direct injection, in particular with hydrogen direct injection, comprising an injector (1) according to one of the preceding claims.

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