Gas injector with highly satisfactory damping properties in operation

Abstract

The present invention relates to a gas injector for injecting gaseous fuel, comprising a solenoid actuator (2) with an armature (20), an internal pole (21) and a coil (22), a closing element (3) with a valve needle (30), wherein the closing element (3) releases and closes a gas path (14) at a sealing seat (11) arranged at a first end of the gas injector, wherein the armature (20) is connected to the closing element (3); a closed lubricant chamber (4) which is filled with a lubricant and in which the armature (20) is arranged, wherein the lubricant ensures lubrication of the armature (20), and a restoring element (10) which restores the closing element (3) into a closed starting position, wherein the lubricant chamber (4) has a first flexible sealing element (51) and a second flexible sealing element (52), an opening brake device (5) which reduces a load of the first flexible sealing element (51) and the second flexible sealing element (52) during the opening operation, and a closing brake device (6) which reduces a load of the first flexible sealing element (51), the second flexible sealing element (52) and the sealing seat (11) during the closing operation.

Description

[0001] Description

[0002] title

[0003] Gas injector with very good damping properties during operation

[0004] State of the art

[0005] The present invention relates to a gas injector for injecting a gaseous fuel, in particular hydrogen or natural gas or the like, with a compact design and very good damping properties during both an opening and closing process of a closing element of the gas injector. The gas injector is designed in particular for direct injection into the combustion chamber of an internal combustion engine.

[0006] Gas injectors are known in various designs from the prior art. One problem with gas injectors is that, due to the gaseous medium being injected, lubrication by the medium is not possible, as is the case with fuel injectors that inject gasoline or diesel, for example. To enable the mobility of the closing element, in particular a valve needle, it is known to use flexible sealing elements, such as bellows. During operation, this can lead to vibration excitations, also due to the gaseous fuel, which can negatively impact the actuation of the closing element during opening and closing.

[0007] Disclosure of the invention

[0008] The gas injector according to the invention for injecting a gaseous fuel with the features of claim 1, however, has the advantage that vibration excitation of components of the gas injector can be suppressed during both the opening and closing processes. This results in very precise adherence to specified injection quantities, opening times, and closing times during operation of the gas injector. In particular, excitation of longitudinal vibrations of a closing element can be prevented. This avoids damage to flexible elements, such as metal bellows, in the gas injector, which ensure the mobility of the closing element in the axial direction of the gas injector. This is achieved according to the invention in that the gas injector comprises a magnetic actuator with an armature, an inner pole, and a coil.The gas injector further comprises a closing element with a valve needle, which opens and closes a gas path for the gaseous fuel at a sealing seat. The sealing seat is arranged at a first end of the gas injector, and the gas injector is preferably an outward-opening injector. The armature is connected to the closing element. Furthermore, a closed lubricant chamber is provided, which is filled with lubricant and in which the movable armature is arranged. The lubricant ensures lubrication of the armature so that no wear occurs on the armature during operation. The lubricant chamber comprises at least a first flexible sealing element, in particular a bellows, which seals the lubricant chamber from the gas path and thus ensures the axial mobility of the closing element, and a second flexible sealing element which provides a compensation chamber for the lubricant chamber.The gas injector further comprises a return element, in particular a closing spring in the form of a cylindrical spring, wherein the return element returns the closing element to a closed initial position. The gas injector further comprises an opening brake device, which reduces the load on the first flexible sealing element and the second flexible sealing element during the opening process, and a closing brake device, which reduces the load on the first flexible sealing element and the second flexible sealing element, as well as on the sealing seat, during the closing process.

[0009] The opening brake device reduces stress on the valve assembly, and in particular on the first flexible element arranged on the closing element. The opening brake device also compensates for the fact that the stroke of the closing element in gas injectors is very large compared to gasoline or diesel fuel injectors, which tends to increase the susceptibility of gas injector components to vibration and leads to high stress and wear on the opening stop surfaces between the armature and the inner pole. The invention can significantly counteract this.

[0010] The closing brake device also ensures during the closing process that the load on the flexible sealing elements remains low and that the closing element does not hit the sealing seat with excessive force, which on the one hand can lead to damage to the components and on the other hand can cause so-called "bouncing" to occur, in which the closing element briefly lifts off the sealing seat again after closing due to the force of the closing process, so that additional gas is briefly introduced into the combustion chamber which cannot be used.

[0011] The subclaims show preferred developments of the invention.

[0012] The gas injector further preferably comprises an anchor bolt, which is arranged in the lubricant chamber and / or connected to the closing element. The opening brake device and / or the closing brake device are arranged on the anchor bolt. This ensures a particularly compact design of the gas injector. Furthermore, by positioning the opening brake device and / or the closing brake device inside the lubricant chamber, hydraulic damping can be achieved during both the opening and closing processes.

[0013] The opening brake device preferably comprises a first piston, a first damping spring, and a first damping chamber. The closing brake device further preferably comprises a second piston, a second damping spring, and a second damping chamber. The opening brake device further preferably also comprises a stop ring, which is preferably arranged on the anchor bolt and only enables damping during the opening process with a delay. This ensures that the damping during the opening process only begins towards the end of the opening stroke.

[0014] To achieve a particularly compact design, the second piston is preferably arranged at least partially, preferably completely, within the first piston. To enable a further compact design of the arrangement, the anchor bolt is preferably passed through the first and second pistons. Thus, the first and second pistons of the two braking devices are annular.

[0015] Further preferably, the first piston has a shoulder on an inner circumference that serves as a stop for the second piston. This further enhances the integration of the first and second pistons into one another, allowing the installation space and structure of the gas injector to be further reduced.

[0016] More preferably, the second piston is arranged with clearance on the anchor bolt. This ensures rapid onset of the damping effect, particularly during the closing process.

[0017] Preferably, the spring force of the first damping spring of the opening brake device is greater than the spring force of the second damping spring of the closing brake device. The spring force of the first damping spring is preferably at least twice as large as the spring force of the second damping spring. This additionally ensures that the damping during the opening process only begins towards the end of the full opening stroke.

[0018] Further preferably, the armature bolt has a shoulder on which the second piston of the closing brake device is arranged. In order to provide the smallest possible diameter for the lubricant chamber, the armature preferably has passage openings for the lubricant.

[0019] Further preferably, the anchor bolt is guided in a guide disc. The guide disc preferably also serves to support the first damping spring of the opening brake device.

[0020] The guide disc further preferably has an axially projecting annular shoulder, which preferably projects at least partially into the armature, which has a corresponding recess.

[0021] The first damping spring is preferably arranged between the guide disc and the first piston. The second damping spring is preferably arranged between a reservoir, which is arranged in the lubricant chamber, and the second piston.

[0022] The first and second flexible elements are preferably bellows, in particular metal bellows. A first diameter of the first flexible element is preferably smaller than a second diameter of the second flexible element.

[0023] The gas injector further preferably comprises first, second, and third needle guides, which guide the valve needle during the opening and closing processes. The first and second needle guides are arranged in the gas path, and the third needle guide is arranged in the lubricant chamber. The reset element is also arranged in the lubricant chamber. Thus, movements of the reset element and the third needle guide, which are lubricated by the lubricant in the lubricant chamber, generate no wear, or at most minimal, negligible wear. The first and second needle guides, which are arranged in the gas path, are thus located outside the lubricant chamber. If, during operation, a tilting moment is exerted on the valve needle by the reset element, this tilting moment can be reliably absorbed by the two first and second needle guides arranged in the gas path.This prevents the valve needle from bending, which could be caused by a tilting moment, thanks to the two first and second needle guides. This ensures that the sealing seat remains closed in all operating situations, preventing the valve needle from tilting at the sealing seat and thus preventing an insufficient closing process. The valve needle is thus securely guided by a double guide outside the lubricant chamber and a guide inside the lubricant chamber.

[0024] Preferably, a first distance A1 between the first and second needle guides in the axial direction XX of the gas injector is smaller than a second distance A2 between the second and third needle guides in the axial direction XX. This ensures particularly good absorption of any tilting moments that may occur by the first and second needle guides. The second distance A2 is preferably at least twice as large, more preferably at least three times as large as the first distance A1. More preferably, the first and / or second and / or third needle guides each have an annular guide region which is connected to the valve needle of the closing element via webs, such that openings for fluid passage are present between the webs.This is particularly advantageous for the first and second needle guides, which are arranged in the gas guide region of the gas injector, in order to allow the largest possible quantities of gas to flow through the first and second guide regions when the gas injector is open. The annular guide region is preferably closed along its entire circumference. In order to keep friction as low as possible during the opening and closing process of the closing element, the width of the annular guide region is selected to be as small as possible. Particularly preferably, three webs are provided which connect the valve needle to the annular guide region. The webs are preferably arranged at equal distances along the circumference.

[0025] According to a particularly preferred embodiment of the invention, the webs between the valve needle and the annular guide regions are arranged at an acute angle to the annular guide region. This makes it possible to increase the flow cross-section in the region of the guides, which is particularly advantageous for the first and second needle guides, which are located in the gas guide region. The webs are preferably arranged downstream of the guide region in the flow direction through the openings. Alternatively, the webs between the valve needle and the annular guide region of the needle guides are arranged at a right angle to the valve needle.

[0026] According to a particularly preferred embodiment of the invention, a plate to which the first flexible sealing element is fixed is also arranged on the valve needle. This allows for a simple connection between the closing element and the first flexible sealing element, which seals the lubricant chamber.

[0027] Preferably, the first and second needle guides are guided on the same component. This component is preferably a cylindrical valve body, on which the sealing seat is also located. This makes it possible to manufacture the guide surfaces for the first and second needle guides in a single setup, which offers significant manufacturing advantages and further reduces manufacturing costs.

[0028] To further reduce the number of components, the third needle guide is preferably also designed to support the return element, which is arranged in the lubricant chamber. The third needle guide can preferably be designed as a plate with openings for the lubricant during the opening and closing process of the closing element.

[0029] Preferably, the closure element with the three needle guides is designed as a single-piece component. This eliminates weld seams or similar components, which are often a source of contamination during operation of the gas injector and can then lead to leaks at the sealing seat or similar problems. A multi-piece closure element constructed from individual welded elements is also preferred to reduce machining volume and save manufacturing costs.

[0030] The first and / or second flexible sealing element is preferably a metal bellows. The metal bellows provides excellent mobility, enabling the axial movements of the closure element, and also allows the metal bellows to be positioned as close as possible to the hot combustion chamber of the internal combustion engine. This allows the axial length of the gas injector to be further reduced. Alternatively, the first flexible sealing element is a plastic bellows, a diaphragm, or a rubber element.

[0031] In order to further reduce the axial length of the gas injector, an electrical connection of the gas injector and / or a gas inlet of the gas injector are preferably arranged on the side of the gas injector.

[0032] The gas injector further preferably has a conical sealing seat. Preferably, the closing element comprises a sealing disc at an end facing the combustion chamber, which opens one or more through openings at a sealing seat. The gas injector is preferably designed as an outward-opening injector. This provides a sealing seat that blows the fuel gas into the combustion chamber in a hollow conical shape.

[0033] Preferably, an oil, especially a synthetic oil or mineral oil, is used as the lubricant. Alternatively, a liquid fuel, especially diesel or gasoline, is used. Further alternatively, a grease is used as the lubricant.

[0034] Short description of the drawing

[0035] An embodiment of the invention will be described in detail below with reference to the accompanying drawings. In the drawing:

[0036] Figure 1 is a schematic sectional view of a gas injector according to a first embodiment of the invention, and

[0037] Figure 2 is a schematic partial sectional view of the gas injector of

[0038] Figure 1.

[0039] Preferred embodiment of the invention

[0040] A gas injector 1 according to a first preferred embodiment of the invention will be described in detail below with reference to Figures 1 and 2.

[0041] As can be seen from Figure 1, the gas injector 1 for introducing a gaseous fuel comprises a magnetic actuator 2, which moves an outwardly opening closure element 3 from a closed state to an open state. Figure 1 shows the closed state of the gas injector.

[0042] The magnetic actuator 2 comprises an armature 20, which is connected to the closing element 3 by means of an armature bolt 24. Furthermore, the magnetic actuator 2 comprises an inner pole 21, a coil 22, and a magnet housing 23, which ensures a magnetic return path of the magnetic actuator. Furthermore, the gas injector 1 comprises a main body 7 with a gas inlet 70 through which the gaseous fuel is supplied. The gas inlet 70 is arranged in the axial direction XX on the main body 7. The main body 7 is connected to a valve housing 8, in which the magnetic actuator 2 is arranged.

[0043] The valve housing 8 is followed by a housing sleeve 19, at the free end of which a sealing seat 11 is provided on a valve seat component 93, at which the closing element 3 opens and closes a passage for the gaseous fuel.

[0044] Figure 1 schematically shows an electrical connection 13, which extends through the main body 7 to the magnetic actuator 2. The electrical connection 13 is arranged on the side of the main body 7.

[0045] The reference numeral 10 denotes a return element for the closing element 3 in order to return it to the closed state shown in Figure 1 after an opening process.

[0046] Figure 1 also shows a gas flow as a gas path 14 through the gas injector 1. The gas flow begins at the gas inlet 70 and is then redirected and leads through the main body 7. The gas flow 14 continues past an outer region of the magnetic actuator 2 through a filter 15 up to the sealing seat 11. Corresponding openings are provided in the respective components, not all of which are shown in Figure 1.

[0047] When the gas injector 1 is opened, the gaseous fuel flows past the outer circumference of the magnetic actuator 2 and the opened sealing seat 11 into a combustion chamber 100 of an internal combustion engine, which is indicated in Figure 1 by the arrows A.

[0048] The closing element 3 comprises a valve needle 30 with a seat plate 30a, which is arranged at the end of the closing element facing the combustion chamber. The sealing seat 11 is formed between the seat plate 30a and the valve seat component 93, which is essentially a cylindrical tube. The closing element 3 further comprises a first needle guide 31, a second needle guide 32, and a third needle guide 33. The two needle guides 31, 32 are preferably formed integrally with the valve needle 30.

[0049] Furthermore, the gas injector 1 comprises a closed lubricant chamber 4. The closed lubricant chamber 4 is completely or partially filled with a liquid lubricant, e.g. oil.

[0050] As can be seen from Figure 1, the lubricant chamber 4 is defined by a first flexible sealing element 51, the inner pole 21, a sleeve 18, a storage body 17, and a second flexible sealing element 52. The first and second flexible sealing elements 51, 52 are each designed as metal bellows.

[0051] The closing element 3 also comprises a plate 34 on which the first flexible sealing element 51 is supported.

[0052] A plurality of connecting bores 77 are formed in the reservoir body 17, connecting the inner region of the second flexible sealing element 52 with the other regions of the lubricant chamber 4. As can be seen from Figure 1, the second flexible sealing element 52 has a relatively large diameter, which is larger than the diameter of the first flexible sealing element 51. Furthermore, a reservoir compression spring 40 is provided, which is supported on the main body 7.

[0053] The second flexible sealing element 52 serves as a compensation chamber for the lubricant contained in the lubricant chamber 4. This allows pressure fluctuations in the lubricant chamber 4 to be compensated.

[0054] The first flexible sealing element 51 is also fixed directly to the closing element 3 at the plate 34 and is connected at the other end to a guide sleeve 35. The third needle guide 33 is guided within the guide sleeve 35.

[0055] Thus, the lubricant chamber 4 has two flexible sealing elements 51, 52 and the accumulator pressure spring 40. The accumulator pressure spring 40 exerts a certain preload, for example 1 x 10 5 Pa, onto the lubricant located in the lubricant chamber 4. If, during an opening process, the lubricant is displaced by the stroke of the closing element 3 or by thermal expansion or cooling of the lubricant, any overpressure / underpressure that may arise inside the lubricant chamber 4 can be compensated for by deflection of the second flexible sealing element 52 in conjunction with a contraction of the accumulator compression spring 40. Thus, the first flexible sealing element 51 cannot exert any unwanted force acting on the closing element 3 via the bellows effective surface.

[0056] The armature bolt 24 with the armature 20 fixed to it is also arranged in the enclosed lubricant chamber 4. Since the lubricant chamber 4 is filled with a lubricant, for example, a liquid fuel such as gasoline or diesel, or a grease or the like, continuous lubrication of the armature 20 is ensured. This compensates for the problem that occurs in the prior art with gaseous fuels, namely the lack of lubrication of the moving parts.

[0057] The gas injector 1 further comprises an opening brake device 5, which reduces a load on the first and second flexible sealing elements 51, 52 and the armature stop during the opening process, and a closing brake device 6, which reduces a load on the first and second flexible sealing elements 51, 52 and the sealing seat 11 during the closing process.

[0058] More precisely, the opening brake device 5 comprises a first piston 53, a damping spring 54, a first damping chamber 55 and a stop ring 56, which is arranged on the anchor bolt 24 at its free end facing away from the sealing seat 11.

[0059] The closing brake device 6 comprises a second piston 63, a second damping spring 64 and a second damping chamber 65.

[0060] As can be seen in particular from Figure 2, the opening brake device 5 and the closing brake device 6 are arranged within a central recess in the accumulator body 17. The opening brake device 5 and the closing brake device 6 are thus arranged on a side of the armature 20 facing away from the sealing seat 11 in the lubricant chamber 4. As can be seen from Figure 2, the first damping spring 54 is supported between a stationary guide disk 9, which is housed in a sleeve 18 that connects the inner pole 21 and the accumulator body 17, and the first piston 53. The first damping spring 54 is arranged in the first damping chamber 55. Lubricant is also present in the first damping chamber 55 because, as can be seen from Figure 2, the armature bolt 24 is guided in the guide disk 9 and lubricant enters the damping chamber 55 via this guide gap.

[0061] The guide disc 9 has a shoulder 91, which protrudes axially toward the sealing seat 11. A correspondingly shaped recess 20a is provided in the armature 20, so that the volume of lubricant in this area of ​​the gas injector is reduced.

[0062] The closing brake device 6 is arranged at the end of the anchor bolt 24 facing away from the sealing seat 11. The second damping spring 64 is arranged in the second damping chamber 65. The second damping spring 64 is arranged between the accumulator body 17 and the second piston 63.

[0063] As can also be seen from Figure 2, the second piston 63 is partially arranged within the first piston 64. A shoulder 25 is provided on the armature bolt 24, which serves as a stop for the second piston 63. In Figure 2, the maximum stroke of the armature 20, which is equal to the maximum opening travel of the closing element 3, is indicated as the first gap H1 by reference symbol H1. A second gap H2 is provided between the stop ring 56 and the second piston 63. A third gap H3 is provided between the second piston 63 and the first piston 53 in the closed position.

[0064] The function of the gas injector 1 is as follows. Starting from the closed position shown in Figures 1 and 2, the coil 22 is energized, pulling the armature 20 in the direction of arrow B (see Figure 2) toward the inner pole 21. Since the armature 20 is firmly connected to the armature bolt, the armature bolt 24 is also moved in the direction of arrow B, causing the closing element 3 to lift from the sealing seat 11 and initiating injection.

[0065] As can be seen from Figure 2, after the second gap H2 has been closed, contact is established between the stop ring 56 and the second piston 63, so that the second piston 63 is also moved in the direction of arrow B upon further energization. This movement of the second piston 63 is also supported by the second damping spring 64. With further energization, the second piston 63 moves in the direction of arrow B, so that the third gap H3, which was present between the second piston 63 and the first piston 53, is overcome. The opening brake device 5 is then activated. The first piston 53 is moved further in the direction of arrow B, against the spring force of the first damping spring 54. This also requires lubricant to be displaced from the first damping chamber 55, thereby slowing down and dampening the opening process.

[0066] The lubricant from the first damping chamber 55 flows via gaps between the first piston 53 and the armature bolt 24 and the second piston 63 and the armature bolt 24 into the second damping chamber 65 and via gaps between the first damping piston 53 and the accumulator body 17 and the first damping piston 53 and the second damping piston 63 into the second damping chamber 65. There is also a flow via gaps between the armature bolt 24 and the guide disk 9. It should be noted that the first piston 53 and the second piston 63 are each arranged with play on the armature bolt 24.

[0067] As soon as the injection is to be ended, the current supply to the magnetic actuator is stopped, so that the return element 10 returns the closing element 2 and thus also the armature bolt 24 towards the starting position shown in Figures 1 and 2. Since the second piston 63 rests against the shoulder 25 on the armature bolt 24, the second piston 63 is also moved in the direction of arrow C during the return. In this case, the second piston 63 must be moved against the spring force of the second damping spring 64 and lubricant must flow back from the second damping chamber via the gap between the first and second pistons and the armature bolt 24 to the first damping chamber 53. This dampens the closing process.

[0068] It should be noted that during the closing process, a damping effect only occurs when the first piston 53 rests against a shoulder 17a of the accumulator body 17. The second piston 63 of the closing brake device 6 then lifts off the shoulder 25 on the anchor bolt 24 and increases the pressure in the second damping chamber 65 to effect damping during the closing process.

[0069] The clearance between the two pistons and the armature pin 24 increases the return speed of the two pistons. It should be noted that instead of the clearance between the pistons and the armature pin 24, corresponding bores can also be formed in the first and second pistons, although this is more complex in terms of manufacturing technology than providing clearance to the armature pin 24.

[0070] The spring force for returning the first piston 53 is preferably twice as high as the spring force for returning the second piston 63. Thus, the gas injector according to the invention can prevent, in particular, the excitation of longitudinal vibrations of the first flexible sealing element 51 (first bellows) and the second flexible sealing element 52 (second bellows) during both the opening and closing processes. Since such longitudinal vibration would increase the number of bellows deflections, the service life of the flexible sealing elements can be significantly increased by the invention. The closing brake device 6 also prevents the closing element 3 from striking the sealing seat 11 excessively during the closing process. This reduces wear on the closing element and / or the sealing seat when closing the gas injector.

[0071] The gas injector 1 shown in Figure 1 is pressure-compensated. This means that the closing element 3 is connected to the guide sleeve 35 via the first flexible sealing element 51. The first flexible sealing element 51, designed as a metal bellows, has an average diameter that is equal to the diameter of the sealing seat 11 against which the closing element 3 seals. This results in no pressure force acting on the closing element 3, so that the magnetic force required to open the closing element 3 can be kept very small and, in particular, is independent of the pressure of the gaseous fuel.

Claims

Claims 1. Gas injector for injecting a gaseous fuel, comprising: - a magnetic actuator (2) with an armature (20), an inner pole (21) and a coil (22), - a closing element (3) with a valve needle (30), wherein the closing element (3) releases and closes a gas path (14) at a sealing seat (11) arranged at a first end of the gas injector, wherein the anchor (20) is connected to the closing element (3), - a closed lubricant chamber (4) which is filled with a lubricant and in which the armature (20) is arranged, wherein the lubricant ensures lubrication of the armature (20), and - a reset element (10) which returns the closing element (3) to a closed initial position, - wherein the lubricant chamber (4) has a first flexible sealing element (51) and a second flexible sealing element (52), wherein the first flexible sealing element (51) is arranged on the closing element (3) and seals the lubricant chamber (4) against the gas path (14), and the second flexible sealing element (52) is arranged on a region of the gas injector opposite the sealing seat (11), - an opening brake device (5) which reduces the load on the first flexible sealing element (51) and the second flexible sealing element (52) during the opening process, and - a closing brake device (6) which reduces the load on the first flexible sealing element (51) and the second flexible sealing element (52) and the sealing seat (11) during the closing process.

2. Gas injector according to claim 1, further comprising an anchor bolt (24) which is arranged in the lubricant chamber (4) and is connected to the closing element (3), wherein the opening brake device (5) and / or the closing brake device (6) are arranged on the anchor bolt (24). Gas injector according to claim 2, - wherein the opening brake device comprises a first piston (53), a first damping spring (54) and a first damping chamber (55) and a stop ring (56) on the anchor bolt (24) and - wherein the closing brake device (6) comprises a second piston (63), a second damping spring (64), and a second damping chamber (65). Gas injector according to claim 3, wherein the second piston (63) is at least partially arranged in the first piston (53). Gas injector according to claim 3 or 4, wherein the anchor bolt (24) passes through the first piston (53) and the second piston (63). Gas injector according to claim 4 or 5, wherein the first piston (53) has a shoulder on an inner circumference as a stop for the second piston (63). Gas injector according to any one of claims 3 to 6, wherein the first piston (53) and / or the second piston (63) is arranged with clearance on the anchor bolt (24). Gas injector according to any one of claims 3 to 7, wherein a spring force of the first damping spring (54) is greater than a spring force of the second damping spring (64).A gas injector according to any one of claims 3 to 8, wherein the anchor bolt (24) has a shoulder (25) as a stop for the opening brake device (5). A gas injector according to any one of claims 3 to 9 further comprising a guide disc (9) wherein the anchor bolt (24) is guided in the guide disc (9). A gas injector according to claim 10, wherein the first damping spring (54) is arranged between the guide disc (9) and the first piston (53). a gas injector according to any of the preceding claims, further comprising: a first needle guide (31), a second needle guide (32), and a third needle guide (33), which are configured to guide the valve needle (30), wherein the first needle guide (31) and the second needle guide (32) are arranged in the gas path (14), and the third needle guide (33) is arranged in the lubricant chamber (4). A gas injector according to claim 12, wherein a first distance (A1) between the first needle guide (31) and the second needle guide (32) in the axial direction (XX) is smaller than a second distance (A2) between the second needle guide (32) and the third needle guide (33) in the axial direction (XX).Gas injector according to claims 12 or 13, wherein the first needle guide (31) and / or the second needle guide (32) and / or the third needle guide (33) each have an annular guide area which is connected to the valve needle (30) via webs such that openings for fluid passage are provided between the webs.

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