Reduced wear gas injector and damping mechanism

Abstract

The present invention comprises a magnetic actuator (2) having an armature (20), an inner magnetic pole (21) and a coil (22), a closing element (3) for opening and closing a gas path (14) at a valve seat (11), the closing element (3) being connected to the closing element (3), a sealed lubricant chamber (4) filled with a lubricant and in which the armature (20) is arranged, the lubricant chamber (4) ensuring lubrication of the armature (20), flexible sealing elements (51, 52) for sealing the lubricant chamber (4) from the gas path (14), and flexible sealing elements (51, 52) arranged in the lubricant chamber (4) for sealing the lubricant chamber (4) from the gas path (14) during a restoration process of the gas injector from an open state to a closed state. and a braking mechanism (6) configured to decelerate a closing element (3), the braking mechanism (6) having a braking bolt (60), a damping chamber (62) filled with a lubricant and in fluid connection with the lubricant chamber (4), and a resilient braking element (61), the braking bolt (60) and the resilient braking element (61) being capable of operatively connecting with the closing element (3) during a restoration process, the braking bolt (60) being configured to displace lubricant from the damping chamber (62) to the lubricant chamber (4) for damping the restoration of the closing element (3) to a closed state during a restoration process of the gas injector.

Description

[Technical field]

[0001] The present invention relates to a gas injector, in particular for internal combustion engines, for injecting a gaseous fuel, in particular hydrogen or natural gas, with reduced wear and improved damping behavior. The gas injector is designed in particular for direct injection into the combustion chamber of an internal combustion engine. [Background technology]

[0002] Gas injectors are known from the prior art in various configurations. The problem with gas injectors is that, in principle, the medium to be injected is gaseous, so that lubrication by the medium is not possible, as is possible with fuel injectors for injecting, for example, gasoline or diesel fuel. This leads to excessive wear during operation compared to fuel injectors for liquid fuels. It would be desirable to provide a gas injector with improved wear behavior. Summary of the Invention

[0003] In contrast, the gas injector for injecting gaseous fuels with the features of claim 1 according to the invention has the advantage that the wear of the gas injector can be significantly reduced. This increases the service life of the gas injector and makes it substantially comparable to the service life of fuel injectors for liquid fuels. Furthermore, a closing process can be performed in which the closing element is significantly better damped when closing the gas valve, thereby reducing or preventing wear of the valve seat and of further components of the closing element. According to the invention, this is achieved in that the gas injector has a lubricant that is located in a sealed lubricant chamber, in which the moving parts of the gas injector are arranged. The gas injector comprises a magnetic actuator with an armature, an inner magnetic pole and a coil. Here, the armature is mechanically connected with a closing element that opens and closes the gas path at the valve seat and is provided for enabling the opening and / or closing movement of the injector. Thus, the armature, which is located in the lubricant chamber and is pulled against the inner pole of the magnetic actuator by the electromagnetic force when the coil is energized, is inside the lubricant chamber and is constantly supplied with lubricant and lubricated. The wear of the armature is thereby significantly reduced compared to gas injectors previously known from the prior art. To ensure the sealing of the lubricant chamber, a flexible sealing element is provided which seals the lubricant chamber in partial areas. Furthermore, the service life of the gas injector can be significantly extended by using a sealed and lubricant-filled lubricant chamber. Here, preferably, the lubricant chamber is completely filled with lubricant.

[0004] The gas injector further includes a braking mechanism arranged in the lubricant chamber, which is configured to decelerate the closure element during a restoration process of the gas injector from the open state to the closed state. The braking mechanism includes a braking bolt, a damping chamber in fluid communication with the lubricant chamber, and an elastic braking element, in particular a spring. During the restoration process, the braking bolt and the elastic braking element are in operative communication with the closure element and / or the armature, and the braking bolt is further configured to displace the lubricant from the damping chamber during the restoration process in order to damp the restoration of the braking bolt and thus the restoration of the closure element. Since part of the deceleration process is provided by the hydraulic adhesion between the braking bolt and the stopper component against which the braking bolt abuts in the open state of the gas injector, the provision of the damping chamber can prevent the vapor lock phenomenon of the liquid lubricant when the hydraulic adhesion is overcome, which can prevent wear due to cavitation in particular.

[0005] This is further supported by the acceleration of the additional mass provided by the braking mechanism. Furthermore, further deceleration is achieved by the displacement of lubricant between the armature and the braking bolt. The return speed of the closing element can be further reduced by friction of the braking bolt with the guide elements etc. All this reduces the impact force of the armature on the stop and the life of the armature can also be further extended.

[0006] The dependent claims indicate preferred developments of the invention. More preferably, the brake bolt comprises a body with, in particular, an abutment surface, which is arranged on the side of the body of the brake bolt facing the closure element, which can be operatively connected with the closure element and which serves as a stop surface. The body is preferably cylindrical. More preferably, a ring flange is arranged on the side of the body facing the closure element. This ring flange preferably serves as a stop surface.

[0007] According to a further preferred embodiment of the invention, a resilient damping element of the damping mechanism is arranged in the damping chamber, which allows a particularly compact construction to be achieved. The resilient damping element is preferably a compression spring, in particular a cylindrical spring.

[0008] More preferably, the damping chamber is in fluid communication with the lubricant chamber via the guiding play of the brake bolt. Preferably, the gas injector further comprises a throttle connecting the damping chamber and the lubricant chamber. This throttle ensures that the damping process can proceed in a defined manner, since the lubricant is transferred from the damping chamber through the throttle and then to the lubricant chamber. The throttle is preferably a small connecting hole between the damping chamber and the lubricant chamber. By selecting the geometric dimensions of the connecting hole, for example the hole diameter and / or length, the damping behavior of the damping mechanism can be adjusted.

[0009] The gas injector further preferably comprises an armature bolt abutting against the closure element, the armature bolt being connected to the armature. The end of the armature bolt not facing the sealing seat of the gas injector is arranged to come into contact with the brake bolt in the closed state of the gas injector. The closure element is preferably a valve needle. Alternatively, it is preferred that the closure element and the armature bolt are fixedly interconnected, particularly preferably via a spring bearing.

[0010] The gas injector preferably further includes an armature bolt guide for guiding the armature bolt. The armature bolt guide serves as a stop for the brake bolt in the open state of the gas injector. In the closed state, a small gap exists between the armature bolt guide and the brake bolt. In the open state, this small gap is overcome by the pressure of the spring of the brake mechanism acting on the brake bolt.

[0011] According to a further preferred embodiment of the invention, the gas injector comprises a guide body arranged in the lubricant chamber with a guide area for guiding the brake bolt, the guide body preferably having a recess, in particular at the end of the guide body guiding the brake bolt facing the sealing seat.

[0012] Preferably, in the closed state of the gas injector, a first gap between the brake bolt and the armature bolt guide has a first width B, which is smaller than a second gap having a second width C between the armature and the inner pole. Here, the axial gap B between the armature bolt guide and the brake bolt is preferably in the range of 1% to 90% of the axial gap C between the armature and the inner pole. Particularly preferably, the axial gap B between the armature bolt guide and the brake bolt is smaller than 25% of the axial gap C, and even more preferably in the range of 3% to 20% of the axial gap C. The axial gap C preferably has a size of 0.05 mm to 3 mm, in particular 0.8 mm.

[0013] Alternatively, the first and second flexible sealing elements are respectively membranes or respectively rubber elements. The membranes may be single or multi-layered and may be fixed to the respective components, for example by laser welding, to seal the lubricant chamber.

[0014] Preferably, the flexible sealing element of the lubricant chamber comprises a first and a second flexible sealing element. Both sealing elements are particularly preferably bellows. The lubricant chamber is thus sealed by two flexible sealing elements, which prevents undesirable positive or negative pressures from arising during displacement of the lubricant in the lubricant chamber, which may exert unintended forces on the closing element of the gas injector, for example via components of the lubricant reservoir. By providing two flexible sealing elements, a balance can be provided by the two flexible sealing elements, even if undesirable forces are exerted on one of the sealing elements, which may increase the pressure in the sealed lubricant chamber. This allows undesirable pressure changes inside the sealed lubricant chamber to be effectively prevented.

[0015] More preferably, the reservoir spring exerts a predetermined force from the outside on the lubricant in the sealed lubricant chamber, preferably between 0.5 and 10×10 5 Pa, particularly preferably 1 to 5 × 10 5 A positive pressure of between 0.01 Pa and 0.02 Pa is applied. This allows a prestressing of the lubricant in the lubricant chamber, which ensures that undesirable deformations that may have an effect on the stroke of the closing element are prevented.

[0016] Particularly preferably, the first flexible sealing element is a first bellows and the second flexible sealing element is a second bellows. Even more preferably, the first and second bellows are identically formed, i.e. have the same average bellows diameter and the same bellows wave number. This can reduce the manufacturing costs, in particular of the gas injector.

[0017] More preferably, the second bellows is connected to the reservoir spring via a spring seat, which allows a simple and inexpensive construction to be realized, and also allows a specific prestress to be applied to the second bellows directly by the reservoir spring, so that the second bellows is slightly more rigid than the first bellows.

[0018] According to a further preferred embodiment of the invention, the gas injector further comprises a first and a second closing element guide, where the first and the second closing element guide are preferably both arranged in the lubricant chamber. The closing element preferably only has both the first and the second closing element guide, so that all guide elements for the closing element are arranged inside the lubricant chamber filled with lubricant. This ensures that the lubrication of all important components of the gas injector is inside the lubricant chamber. This allows the service life of the gas injector to be practically equivalent to the service life of an injector for liquid fuels.

[0019] Preferably, oil, especially mineral oil, is used as the lubricant. Alternatively, liquid fuel, especially diesel fuel or gasoline, is used. As a further alternative, grease or PAO oil (polyalphaolefin) or ester oil or polyglycol oil is used as the lubricant.

[0020] More preferably, the first and second flexible sealing elements are single- or multi-layer bellows, respectively. The bellows are preferably made of metal or alternatively of plastic. The first bellows is preferably fixed at a first end directly to the closure element and at another end to a housing component of the gas injector. Fixing can be effected, for example, by a welded joint for metal bellows.

[0021] Preferably, the gas path for the gas fuel is provided in the region between the valve housing of the gas injector and the actuator housing of the gas injector, whereby the actuator can be placed in the housing and at least partially preassembled as an assembly, whereby the lubricant chamber can be placed inside the actuator housing in a relatively simple manner.

[0022] Alternatively, the gas path of the gas fuel is formed through the area of ​​the magnetic actuator, in particular through the coil chamber in which the coil of the magnetic actuator is arranged. This makes it possible to dispense with a separate actuator housing for the magnetic actuator. Particularly preferably, here, electrical contacts are extended through the gas path of the gas fuel. This can in particular reduce the complexity of the construction of the gas injector. It should be noted that electrical contacts extending through the gas space must of course be sealed from the outside.

[0023] Further preferably, a filter is arranged in the gas path for the gas fuel in order to filter out solid particles which may be present in the gas fuel or which result from production or assembly.Further preferably, a guide element is provided on the closing element, in particular if the closing element is a long valve needle.

[0024] Preferably, the gas injector is an outward opening injector. More preferably, the gas injector is pressure balanced. Thereby, the force required to open the gas injector by the magnetic actuator is independent of the gas pressure. Thus, the time to open and close the injector after the start and end of the current application, respectively, is also independent of the gas pressure. This also allows operation at various gas pressures. If a smaller blowing volume is desired, the gas pressure can be reduced, and if a larger blowing volume is desired, the gas pressure can be increased. The injector is pressure balanced when the average diameter of the bellows is equal to the diameter of the valve seat contact line between the closing element and the valve body. However, the bellows average diameter can be made smaller or larger than the valve seat diameter. If the bellows average diameter is smaller than the valve seat diameter, an increase in gas pressure reduces the total closing force on the valve needle, and the injector opens faster when energized and closes slower after energization. This increases the gas blowing volume. If the bellows average diameter is larger than the valve seat diameter, an increase in gas pressure will increase the closing force on the valve needle, which can also compensate for the increased amount of valve seat leakage caused by increased gas pressure.

[0025] The return is preferably effected by a return spring. In the case of a pressure-balanced injector, particularly in the closed state of the gas injector, no compressive force is exerted on the valve needle by the gas fuel, and thus the load on the closing element can be significantly reduced.

[0026] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic cross-sectional view of a gas injector according to a first exemplary embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic enlarged partial cross-sectional view of the gas injector of FIG. 1. [Diagram 3] FIG. 2 is a schematic enlarged partial cross-sectional view of a gas injector according to a second exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, a gas injector 1 according to a first preferred exemplary embodiment of the present invention will be described in detail with reference to FIGS. As can be seen in Figure 1, a gas injector 1 for introducing a gaseous fuel comprises a magnetic actuator 2 which moves a closure element 3, which in this exemplary embodiment is an outwardly opening valve needle, from a closed state to an open state, where Figure 1 shows the gas injector in the closed state.

[0029] The magnetic actuator 2 comprises an armature 20 which abuts against the closure element 3 by means of an armature bolt 24. The magnetic actuator 2 further comprises an inner magnetic pole 21, a coil 22 and a magnetic housing 23 which ensures the magnetic feedback of the magnetic actuator.

[0030] The gas injector 1 further comprises a body 7 with a connecting tube 70 through which the gaseous fuel is supplied. Here, a valve housing 8 is fixed to the body 7, in which the magnetic actuator 2 is arranged. A housing sleeve 19 and a valve tube 90 are connected to the valve housing 8, the free end of which is provided with a valve seat 11, at which a closing element 3 opens and closes the passage for the gaseous fuel.

[0031] FIG. 1 shows diagrammatically an electrical connection 13 which is guided through the body 7 to the magnetic actuator 2 . Reference number 10 denotes a restoring element for returning the closure element 3 to the closed state shown in FIG. 1 after the opening process.

[0032] 1 further illustrates the gas flow as gas path 14 through gas injector 1, where the gas flow begins at connecting tube 70 and is then deflected into annular space 80 between valve housing 8 and body 7. Here, gas flow 14 passes past the outer region of magnetic actuator 2 and through filter 15 before proceeding to just before valve seat 11, where corresponding openings are provided in each component, not all of which are shown in FIG.

[0033] When the gas injector 1 is open, gaseous fuel flows, as shown by arrow A in FIG. 1, around the periphery of the magnetic actuator 2 and through the open valve seat 11 into the combustion chamber of the internal combustion engine.

[0034] The closing element 3 thus opens and closes the gas path 14 at the valve seat 11. As can be seen in detail from Fig. 1, for guidance, a first guiding area 31 and a second guiding area 32 are provided between the closing element 3 and the valve body 9. The first guiding area 31 is formed directly between the closing element 3 and the valve body 9, close to the valve seat. The second guiding area 32 is formed between the spring bearing 16 and the valve body 9. The spring bearing 16 is fixedly connected to the closing element 3, and the restoring element 10 is supported between the valve body 9 and the spring bearing 16.

[0035] The gas injector 1 further comprises a sealed lubricant chamber 4. The sealed lubricant chamber 4 is completely or partially filled with a liquid lubricant, for example oil. As can be seen in Fig. 1, the lubricant chamber 4 is defined by a first flexible sealing element 51, an inner pole 21, a magnetic housing 23, a guide body 18, and a second flexible sealing element 52. The first and second flexible sealing elements 51, 52 are each formed as a bellows. Here, the first and second flexible sealing elements 51, 52 are formed identically.

[0036] It should be noted that instead of bellows the flexible sealing elements 51, 52 could also be, for example, membranes, tubes etc. 1, the second flexible sealing element 52 is fixed to the reservoir spring seat 41, for example by a welded joint. The gas injector 1 further comprises a reservoir compression spring 40, which is supported in the body 7 and prestresses the second flexible sealing element 52 via the reservoir spring seat 41. The guide body 18 is provided with a connection hole 18a, so that the lubricant present in the lubricant chamber 4 is also present in the inner region of the second flexible sealing element 52.

[0037] The first flexible sealing element 51 is fixed directly to the closure element 3 and at another end is connected to the valve body 9, whereby the valve body 9 is provided with a transverse hole 91, by means of which there is a fluid connection between the inner space of the first flexible sealing element 51 and the inner space of the valve body 9.

[0038] The lubricant chamber 4 therefore has two flexible sealing elements 51, 52 and a reservoir compression spring 40. The reservoir compression spring 40 applies a certain prestress to the lubricant present in the lubricant chamber 4, for example 1×10 5 Pa. Thus, during the opening process, positive / negative pressures that may arise inside the lubricant chamber 4 in case of a displacement of the lubricant due to the stroke of the closure element 3 or even due to thermal expansion or cooling of the lubricant, can be counterbalanced by the deflection of the second flexible sealing element 52 associated with the contraction of the reservoir compression spring 40. This allows the flexible sealing element 51 to be prevented from unintentional forces acting on the closure element 3 via the bellows working surface.

[0039] The armature bolts 24, to which the armature 20 is fixed, are arranged in the sealed lubricant chamber 4. The lubricant chamber 4 is filled with a lubricant, for example a liquid fuel such as gasoline or diesel fuel, or grease, so that the armature 20 is continuously lubricated. This compensates for the problem that occurs in the prior art with gaseous fuels, namely that the moving parts are not lubricated.

[0040] 1, a filling channel 17a is provided for filling the sealed lubricant chamber 4. The filling channel 17a is closed fluid-tight by a closing ball 17.

[0041] A braking mechanism 6 is further arranged in the sealed lubricant chamber 4. The braking mechanism 6 comprises a braking bolt 60, a damping chamber 62 filled with lubricant and a resilient damping element 61. The damping chamber 62 is in fluid communication with the lubricant chamber 4.

[0042] The brake bolt 60 and the elastic brake element 61 are in operative connection with the closure element 3 during the restoring process of the gas injector to the closed initial position, whereby further damping is achieved during the restoring process of the brake bolt 60 to the closed state of the gas injector (FIG. 1) due to the displacement of lubricant from the damping chamber 62 to the lubricant chamber 4 during the restoring process.

[0043] The brake bolt 60 is guided in the guide body 18 . As can be further seen from Fig. 1, the damping chamber 62 is formed directly on the brake bolt 60 on the side of the brake bolt 60 that does not face the valve seat 11. This can be seen in detail from Fig. 2. The damping chamber 62 is connected via a small hole, a throttle 63, to the connecting bore 18a and thus to the main area of ​​the lubricant chamber 4. The brake spring 61 is arranged in the spring chamber 67.

[0044] The brake bolt 60 has an abutment surface 60a, which is in contact with the armature bolt 24. Here, in the closed state shown in Fig. 2, there is a first gap 101 between the brake bolt 60 and the stationary armature bolt guide 25. The armature bolt guide 25 guides the armature bolt 24 during the opening and closing processes.

[0045] As can further be seen from Fig. 2, the brake spring 61 is arranged between the brake bolt 60 and the guide body 18. Here, the brake bolt 60 has a flange 60b, which is provided with play relative to the guide body 18. Furthermore, the guide body 18 is provided with a passage 65, which can be formed, for example, as a slit, at the end of the guide body 18 facing the armature bolt guide 25. A fluid connection for the lubricant can thus be provided from the spring chamber 67 via the guide play 64 and the passage 65 to the lubricant chamber 4.

[0046] In the closed state, a first gap 101 is further formed between the abutment surface 60a of the brake bolt 60 and the armature bolt guide 25. Here, the gap 101 has a first width B, which is smaller than a second width C between the armature 20 and the inner pole 21 in the second gap 102 (see Figures 1 and 2). This ensures that the stroke of the brake bolt 60, which is axially prestressed by the compression spring 61, is smaller than the stroke of the armature 20. Thus, sufficient fluid can flow from the lubricant chamber 4 through the throttle 63 to the damping chamber 62 during the blowing process.

[0047] During the closing process, the armature bolt 24 hits the abutment surface 60a of the brake bolt 60, which pushes the brake bolt 60 towards the fluid in the damping chamber 62, as shown by the arrow 66 in Figure 2. The throttle 63 allows the fluid to be pushed out of the damping chamber 62 slowly rather than immediately, providing a damping effect during the closing process. This prevents excessive wear on the valve seat 11 and the armature 20, as the closing process is damped through the return of the brake bolt 60.

[0048] The damping process is further supported by the damping spring 61 and by the hydraulic adhesion of the brake bolt 60 in the armature bolt guide 25. Here, in this area between the armature bolt guide 25 and the abutment surface 60a of the brake bolt 60, cavitation during the closing process can be prevented by the damping chamber 62. The friction of the brake bolt 60 in the guide 18 also slows down the restoring process, and moreover, across the lubricant chamber 4, the accelerating mass of the mobile component displaces the lubricant in the closed lubricant chamber, thereby resulting in a further deceleration during the closing process.

[0049] By selection of the diameter and / or length of the constriction 63 the damping behavior can be adjusted individually for each gas injector. It should be noted that the stop surface between the damping bolt 60 and the armature bolt guide 25 can preferably be formed wedge-shaped, i.e. not perpendicular to the central axis XX of the gas injector. Alternatively or additionally, the abutment surface 60a or the end face of the armature bolt guide 25 facing the damping bolt 60 can be provided with radial slits, which further reduces and prevents cavitation effects.

[0050] Here, the gas injector 1 shown in Fig. 1 is pressure balanced, i.e. the closure element 3 is connected with the valve body 9 via a first flexible sealing element 51, which is formed as a metal bellows and has an average diameter equal to the diameter at the valve seat 11, in particular the diameter with which the closure element 3 seals at the valve seat 11. Thereby, no compressive forces arise on the closure element 3 and therefore the magnetic force required to open the closure element 3 can be kept very small and is in particular independent of the pressure of the gas fuel.

[0051] Thus, according to the invention, if the closure element 3 is opened by the action of the magnetic actuator 2 (movement of the closure element 3 to the left in FIG. 1) and gas injection is performed, then during the return of the closure element 3, reliable damping can be performed immediately before the closure element is pressed against the valve seat 11. Here, the brake bolt 60 is pushed by the armature bolt 24 in the direction of the damping chamber 62 and moves only slowly, i.e. as slowly as the lubricant is pushed out of the damping chamber 62 through the throttle 63 into the lubricant chamber 4. This effectively slows down the closing speed of the closure element 3 significantly before it hits the valve seat 11. This effectively reduces the wear of the valve seat 11 and of the closure element 3, whereby the brake mechanism 6 furthermore allows a quieter operation of the gas injector. The so-called closing crash, in which the element hits the valve seat hard and crashes back, can also be effectively prevented.

[0052] 3 shows a partial cross-sectional view of a gas injector according to a second exemplary embodiment of the present invention, in which identical or functionally identical parts are numbered similarly to the first exemplary embodiment. FIG. 3 shows a brake mechanism 6 which is designed differently from the brake mechanism 6 in the first exemplary embodiment. In the second exemplary embodiment, the damping chamber 62 is no longer connected to the lubricant chamber 4 via a throttle, but via a guide play 64 between the brake bolt 60 and the guide body 18. The connection to the lubricant chamber 4 is then ensured by one or more passages 65 which are formed radially at the end face of the guide body 18. The brake spring 61 is now arranged in the damping chamber 62. This allows, on the one hand, to reduce the axial construction space of the brake mechanism 6, so that the entire gas injector 1 can be designed axially shorter. Furthermore, it is not necessary to provide a throttle, as in the first exemplary embodiment. Thus, during the restoring process, the armature bolt 24 presses against the abutment surface 60a of the brake bolt 60, which in turn is pushed in the direction of the arrow 66 towards the guide body 18. The lubricant is then pushed back from the damping chamber 62 via the guide play 64 and at least one passage 65 into the lubricant chamber 4. A further advantage of the second exemplary embodiment is that there is a smaller volume of lubricant in the damping chamber 62. This may also reduce vibrations along the brake bolt 60 that may result, in particular, from the elasticity of the lubricant.

[0053] Otherwise, the second exemplary embodiment corresponds to the first exemplary embodiment, and therefore reference may be made to the description of the first exemplary embodiment. Thus, the gas injector 1 can provide reduced wear of the moving parts, in particular the valve seat 11, the armature 20 and the armature bolts 24, as detailed in both exemplary embodiments. Furthermore, the heat dissipation from the magnetic actuator 2 can be significantly improved by the sealed lubricant chamber 4 containing the liquid lubricant. Furthermore, both flexible sealing elements 51, 52 can prevent unintended forces from acting on the closure element 3.

Claims

1. a magnetic actuator (2) having an armature (20), an inner pole (21), and a coil (22); a closure element (3) for opening and closing a gas path (14) at a valve seat (11), the armature (20) being connected to the closure element (3); a sealed lubricant chamber (4) filled with a lubricant and in which the armature (20) is placed, the lubricant ensuring lubrication of the armature (20); a flexible sealing element (51, 52) sealing the lubricant chamber (4) from the gas path (14); a braking mechanism (6) arranged in the lubricant chamber (4), configured to decelerate the closing element (3) during a restoration process of the gas injector from an open state to a closed state, the braking mechanism (6) comprises a braking bolt (60), a damping chamber (62) filled with a lubricant and in fluid connection with the lubricant chamber (4), and an elastic braking element (61), the braking bolt (60) and the elastic braking element (61) being operable to connect with the closure element (3) during a restoring process, the braking bolt (60) being configured to displace lubricant from the damping chamber (62) to the lubricant chamber (4) for damping the return of the closure element (3) to a closed state during a restoring process of the gas injector, The gas injector, wherein the brake bolt (60) has an abutment surface (60a), which is arranged on a side of the brake bolt facing the closure element (3), can be operatively connected to the closure element (3), and serves as a stop surface for the brake bolt.

2. A magnetic actuator (2) having an armature (20), an inner magnetic pole (21), and a coil (22); a closure element (3) for opening and closing a gas path (14) at a valve seat (11), the armature (20) being connected to the closure element (3); a sealed lubricant chamber (4) filled with a lubricant and in which the armature (20) is placed, the lubricant ensuring lubrication of the armature (20); a flexible sealing element (51, 52) sealing the lubricant chamber (4) from the gas path (14); a braking mechanism (6) arranged in the lubricant chamber (4), configured to decelerate the closing element (3) during a restoration process of the gas injector from an open state to a closed state, the braking mechanism (6) comprises a braking bolt (60), a damping chamber (62) filled with a lubricant and in fluid connection with the lubricant chamber (4), and an elastic braking element (61), the braking bolt (60) and the elastic braking element (61) being operable to connect with the closure element (3) during a restoring process, the braking bolt (60) being configured to displace lubricant from the damping chamber (62) to the lubricant chamber (4) for damping the return of the closure element (3) to a closed state during a restoring process of the gas injector, The gas injector further comprising a throttle (63), wherein said damping chamber (62) is in fluid communication with said lubricant chamber (4) via said throttle (63).

3. A magnetic actuator (2) having an armature (20), an inner magnetic pole (21), and a coil (22); a closure element (3) for opening and closing a gas path (14) at a valve seat (11), the armature (20) being connected to the closure element (3); a sealed lubricant chamber (4) filled with a lubricant and in which the armature (20) is placed, the lubricant ensuring lubrication of the armature (20); a flexible sealing element (51, 52) sealing the lubricant chamber (4) from the gas path (14); a braking mechanism (6) arranged in the lubricant chamber (4), configured to decelerate the closing element (3) during a restoration process of the gas injector from an open state to a closed state, the braking mechanism (6) comprises a braking bolt (60), a damping chamber (62) filled with a lubricant and in fluid connection with the lubricant chamber (4), and an elastic braking element (61), the braking bolt (60) and the elastic braking element (61) being operable to connect with the closure element (3) during a restoring process, the braking bolt (60) being configured to displace lubricant from the damping chamber (62) to the lubricant chamber (4) for damping the return of the closure element (3) to a closed state during a restoring process of the gas injector, The gas injector further includes an armature bolt (24), the armature bolt (24) abutting against the closure element (3) and fixedly connected to the armature (20), wherein an end of the armature bolt (24) that does not face the valve seat (11) of the gas injector abuts against the brake bolt (60) when the gas injector is in a closed state.

4. A magnetic actuator (2) having an armature (20), an inner pole (21), and a coil (22); a closure element (3) for opening and closing a gas path (14) at a valve seat (11), the armature (20) being connected to the closure element (3); a sealed lubricant chamber (4) filled with a lubricant and in which the armature (20) is placed, the lubricant ensuring lubrication of the armature (20); a flexible sealing element (51, 52) sealing the lubricant chamber (4) from the gas path (14); a braking mechanism (6) arranged in the lubricant chamber (4), configured to decelerate the closing element (3) during a restoration process of the gas injector from an open state to a closed state, the braking mechanism (6) comprises a braking bolt (60), a damping chamber (62) filled with a lubricant and in fluid connection with the lubricant chamber (4), and an elastic braking element (61), the braking bolt (60) and the elastic braking element (61) being operable to connect with the closure element (3) during a restoring process, the braking bolt (60) being configured to displace lubricant from the damping chamber (62) to the lubricant chamber (4) for damping the return of the closure element (3) to a closed state during a restoring process of the gas injector, The gas injector further comprises a guide body (18) arranged in the lubricant chamber (4), the guide body (18) being configured for guiding the brake bolt (60).

5. 5. A gas injector according to any one of claims 1 to 4, wherein the elastic damping element (61) is arranged in the damping chamber (62).

6. 6. A gas injector according to claim 1, wherein the damping chamber (62) is in fluid connection with the lubricant chamber (4) via a guiding play (64) of the brake bolt (60).

7. 4. The gas injector according to claim 3, further comprising an armature bolt guide (25) in which the armature bolt (24) is guided, wherein the armature bolt guide (25) serves as a stop for the brake bolt in an open state of the injector.

8. 8. The gas injector according to claim 4 or 7, wherein in a closed state of the gas injector, a first gap (101) between the brake bolt (60) and the armature bolt guide (25) has a first width (B), said first width (B) being smaller than a width (C) of a second gap (102) between the armature (20) and the inner pole (21).

9. 9. The gas injector according to claim 1, wherein a restoring element (10) for restoring the closing element (3) is arranged in the lubricant chamber (4) and / or a first guide area (31) and a second guide area (32) of the closing element (3) are arranged in the lubricant chamber (4).

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