Gas injection valve for internal combustion engines

Abstract

The invention relates to a gas injection valve (10) for injecting gaseous fuel into the combustion chamber of an internal combustion engine, said gas injection valve comprising: a housing (11) which has a fuel inlet (24) and an injection valve seat (26) with an outwardly opening valve sealing surface (131); a gas chamber (25) which extends from the fuel inlet to the injection valve seat; an injection valve member (31) which is mounted so as to be displaceable along a longitudinal axis and which is designed to co-operate with the injection valve seat; a compression spring (51) which applies a closing force to the injection valve member on the valve sealing surface; an electromagnetically operable actuator assembly (41) for adjusting the injection valve member along the longitudinal axis; a spring disc (52) attached to the injection valve member in an end region of the injection valve member facing away from the injection valve seat, wherein the compression spring is supported at a first end relative to the housing so as to be stationary on the housing and at a second end on the spring disc, wherein the housing has a stop shoulder (124) which forms a stroke stop for a stop surface (524) of the spring disc facing the injection valve seat.

Description

[0001] GAS INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES

[0002] Field of the invention

[0003] The present invention relates to a gas injection valve for injecting gaseous fuel, in particular hydrogen or natural gas, into the combustion chamber of an internal combustion engine.

[0004] Background of the invention

[0005] In a gas combustion engine, an internal combustion engine is powered by a gaseous fuel, such as natural gas or hydrogen. When operated with high-quality fuel gases such as methane, high efficiencies with clean combustion and a good carbon dioxide (CCt) balance are possible. In terms of carbon dioxide (CCt) emissions, hydrogen is also considered a promising energy carrier, as the energy conversion of hydrogen in the combustion engine can be largely CCt-free and without carbon-containing pollutants such as carbon monoxide and hydrocarbons.

[0006] A gas injector is described, for example, in WO2022135800 A1. The gas injector for injecting a gaseous fuel comprises a magnetic actuator with an armature, an inner pole and a coil, a closing element which opens and closes a gas path at a valve seat, the armature being connected to the closing element, a sealed lubricant chamber which is filled with a lubricant and in which the armature is arranged, the lubricant ensuring lubrication of the armature and a first flexible sealing element and a second flexible sealing element which seal the lubricant chamber from the gas path. The armature, which is mechanically connected to the closing element, is provided to enable a movement to open and / or close the injector.The armature, which is located in the lubricant chamber and is pulled against the inner pole of the magnetic actuator due to electromagnetic forces when the coil is energized, is therefore located inside the lubricant chamber and is constantly supplied with lubricant and lubricated. This reduces wear on the armature. The armature, which is surrounded by lubricant, is dampened in its movement when it hits the inner pole, so that the impulse transferred from the armature to the inner pole is lower than without lubricant. To ensure that the lubricant chamber is sealed, the first and second flexible sealing elements are provided which seal off parts of the lubricant chamber. One challenge with gas injectors is that, due to the gaseous medium to be injected, lubrication by the medium is not possible, as is the case, for example, with fuel injectors that inject gasoline or diesel.This can result in excessive wear during operation compared to fuel injectors for liquid fuels.

[0007] Description of the invention

[0008] Compared to fuel injectors that inject gasoline or diesel, a sufficiently large injection cross-section or flow cross-section and the stroke of the gas injector needle are of greater importance for a gas injector. Furthermore, compared to fuel injectors where the fuel itself, such as diesel, can be used as a lubricant, solutions for the unfavorable lubricating properties of the gas used, such as hydrogen, are desirable.

[0009] It is therefore an object of the invention to provide a gas injection valve which at least partially improves the prior art.

[0010] This object is achieved with a gas injection valve having the features of the independent claim. Advantageous embodiments of the invention are given in the dependent claims and in the present description and figures.

[0011] The invention relates to a gas injection valve for injecting gaseous fuel into the combustion chamber of an internal combustion engine, comprising a housing extending along a longitudinal axis, which has a fuel inlet and an injection valve seat with an outwardly opening valve sealing surface, a gas chamber arranged in the housing, which runs from the fuel inlet to the injection valve seat, an injection valve member arranged so as to be adjustable along the longitudinal axis, which is designed to cooperate with the injection valve seat, a compression spring which applies a closing force to the valve sealing surface of the injection valve member, an electromagnetically actuated actuator arrangement for adjusting the injection valve member along the longitudinal axis, a spring plate attached to the injection valve member in an end region of the injection valve member facing away from the injection valve seat,wherein the compression spring is supported at a first end relative to the housing in a fixed position on the housing and at a second end on the spring plate, wherein the housing has a stop shoulder which forms a stroke stop for a stop surface of the injection valve seat facing the,

[0012] spring plate forms.

[0013] By activating the electromagnetic actuator arrangement, the injection valve member can be moved toward the injection valve seat against the spring force of the compression spring to open the gas injection valve. By deactivating the electromagnetic actuator arrangement, the injection valve member can be moved in the direction away from the injection valve seat due to the spring force of the compression spring until the injection valve member comes into contact with the valve sealing surface with a valve member sealing surface to close the gas injection valve.

[0014] The spring plate can provide a reliable seat for the second end of the compression spring. This can be particularly advantageous for a gas injection valve, since the compression spring is generally larger than that of diesel or gasoline injection valves. The compression spring can, in particular via the spring plate, apply a closing force to the valve sealing surface of the injection valve member. The spring plate can also be used to define or set the maximum stroke of the injection valve member via the stroke stop. The spring plate is therefore preferably adjustable along the longitudinal axis together with the injection valve member.

[0015] In one embodiment, the spring plate has a central recess through which the injection valve member is passed.

[0016] Preferably, the injection valve member is passed through the central recess of the spring plate with a sliding fit. The spring plate can therefore be attached through the central recess to the end region of the injection valve member facing away from the injection valve seat. Furthermore, because the injection valve member is passed through the central recess with a sliding fit, the axial position of the spring plate relative to the injection valve member can be adjusted, thus allowing the maximum stroke of the injection valve member to be changed or adjusted.

[0017] In one embodiment, the injection valve member has a chamfered, circular cross-section with at least one valve member chamfer in the region of the spring plate.

[0018] The valve member chamfer offers the advantage that an axial torque can be applied to the injection valve member. This can be particularly advantageous in conjunction with a threaded cap, as described below.

[0019] In one embodiment, the central recess has a spring plate chamfer arranged parallel to the valve member chamfer. The spring plate chamfer offers the advantage that a torque to be applied to the injection valve member can be applied via the spring plate.

[0020] In one embodiment, the spring plate has at least two blind holes on a side facing away from the injection valve seat. The spring plate can be held with a suitable tool via the blind holes in order to apply torque to the spring plate or the injection valve member. In one variant, through holes can be formed instead of the blind holes.

[0021] In one embodiment, the gas injection valve has a threaded cap which can be screwed onto the injection valve member via a thread formed on the injection valve member in the end region of the injection valve member facing away from the injection valve seat in such a way that the compression spring presses the spring plate against a contact surface of the threaded cap facing the injection valve seat.

[0022] The axial position of the spring plate relative to the injection valve element can therefore be set or fixed via the threaded cap. The compression spring can therefore press with its second end onto the spring plate in the axial position of the spring plate determined by the threaded cap and apply a closing force to the valve sealing surface of the injection valve element. The axial position of the spring plate relative to the injection valve element, which is set via the threaded cap, also makes it possible to set the maximum stroke of the spring plate or of the injection valve element between closing and opening of the gas injection valve.

[0023] When screwing on the threaded cap, as mentioned above, a valve member chamfer and / or a spring plate chamfer may be particularly advantageous in order to hold the injection valve member and / or the spring plate or to be able to apply a torque.

[0024] In one embodiment, a stroke adjusting disc is arranged between a bottom surface of the threaded cap facing the injection valve seat and an end surface of the injection valve member facing away from the injection valve seat.

[0025] The stroke adjusting disc can be used to adjust the screw-in depth or screw depth of the threaded cap onto the thread of the injection valve element. The maximum stroke of the spring plate or of the injection valve element can be set using the adjustable screw-in depth. The maximum stroke of the spring plate or of the injection valve element can therefore be easily adjusted using the stroke adjusting disc. Advantageously, the maximum stroke of the injection valve element can be adjusted using a suitable stroke adjusting disc after testing the injection quantities.

[0026] The stroke adjustment disc is preferably made of a metal, preferably of a hardened metal.

[0027] In one embodiment, the gas injection valve has a tappet which is adjustable along the longitudinal axis by the electromagnetically actuated actuator arrangement and which is connected with an end surface facing the injection valve seat to a bottom surface of the

[0028] threaded cap hits .

[0029] The actuator arrangement can therefore adjust the injection valve element along its longitudinal axis via the tappet. By activating the electromagnetic actuator arrangement, the tappet can be adjusted in the direction of the injection valve seat. By deactivating the electromagnetic actuator arrangement, the tappet can be adjusted in the direction away from the injection valve seat.

[0030] In one embodiment, the stop shoulder has an annular stop surface.

[0031] Preferably, the annular stop surface of the stop shoulder is horizontal. Due to the annular stop surface of the stop shoulder, a stroke stop force upon impact of the spring plate can be absorbed radially symmetrically by the housing.

[0032] In one embodiment, the spring plate has a cup-like shape with a base and a circumferential side wall, wherein the side wall extends from the base in the direction of the injection valve seat in such a way that the second end and a part of the compression spring adjoining the second end can be received in the spring plate.

[0033] The part of the compression spring adjoining the second end can comprise one, two, three, or more coils of the compression spring. The cup-shaped shape can provide improved support for the compression spring in the region of the second end of the compression spring, particularly in the radial direction. In one embodiment, the stop surface of the spring plate is formed by an end of the side wall of the spring plate facing the injection valve seat.

[0034] In particular, the end of the circumferential side wall of the spring plate facing the injection valve seat can interact with the annular stop surface of the stop shoulder.

[0035] In one embodiment, the housing has a cup-shaped compression spring seat which is designed to receive the first end and a part of the compression spring adjoining the first end.

[0036] The part of the compression spring adjoining the first end can comprise one, two, three, or more coils of the compression spring. The compression spring seat can provide improved support for the compression spring in the region of the first end of the compression spring, particularly in the radial direction.

[0037] In one embodiment, the fuel inlet is arranged in a side wall of the housing at a height between the compression spring and the injection valve seat.

[0038] The housing may have a constriction below the first end of the compression spring through which the injection valve member is passed.

[0039] The constriction can be formed by a shoulder of the housing. A compression spring seat can be arranged on the shoulder of the housing, or, in an embodiment without a compression spring seat, the first end of the compression spring can be fixedly supported relative to the housing. A spring chamber in which the compression spring is arranged can be arranged above the shoulder.

[0040] In one embodiment, the constriction can be formed by a bore in a transverse wall of the housing. The injection valve member can be guided through the bore with a sliding fit. In one embodiment, a guide sleeve can be arranged in the bore, through which the injection valve member is guided with a sliding fit. In an embodiment without a guide sleeve, the bore can have a coating to minimize friction.

[0041] Below the transverse wall, the gas chamber can be arranged with a larger diameter than the constriction. Above the transverse wall, a spring chamber can be arranged, in which the compression spring is located. The spring chamber can be connected to the gas chamber by at least one through-bore in the transverse wall.

[0042] The transverse wall with at least one through-bore can reduce, minimize, or prevent the propagation of pressure oscillations from the gas chamber into the spring chamber. This allows the spring chamber to be decoupled from the gas chamber with respect to pressure oscillations, and disturbances to the movement of the spring plate can be dampened, minimized, or prevented.

[0043] Furthermore, the at least one through-bore can compensate for a reduction in the volume of the spring chamber caused by a movement of the spring plate toward the injection valve seat and an associated pressure buildup in the spring chamber. In one variant, a clearance between the guide sleeve of the transverse wall and the injection valve member can assume one or more functions of the at least one through-bore in the transverse wall, in particular the function of pressure equalization.

[0044] In an embodiment without a guide sleeve in the transverse wall, a play between the bore of the transverse wall and the injection valve member guided through the bore can take over one or more functions of the at least one passage bore in the transverse wall, in particular the function of pressure compensation.

[0045] In one variant, the transverse wall has at least one through-bore and the injection valve member is guided with a clearance through the bore of the transverse wall or the guide sleeve of the transverse wall.

[0046] The terms "above", "below", "top", "bottom" etc. are to be understood in the context of the present disclosure with respect to the flow direction of the fuel from the fuel inlet to the injector seat, i.e. according to the orientation as shown in the figures.

[0047] By arranging the fuel inlet at a height between the compression spring and the injection valve seat, e.g., below the transverse wall, the fuel inlet can lead directly into the gas chamber with a large cross-section. This can be particularly advantageous for a gas injection valve, since a large flow cross-section is generally desired for a gaseous fuel. The fuel inlet is preferably formed in a side wall of the housing. The fuel inlet can therefore open laterally into the gas chamber.

[0048] In an alternative embodiment, the fuel inlet can be formed above the gas space. In such an embodiment, the fuel inlet can open into the gas space from above.

[0049] In one embodiment, the gas injection valve has a, preferably electrical, control which is designed to electromagnetically activate the actuator arrangement when the gas injection valve is closed during a braking period.

[0050] By activating the electromagnetic actuator arrangement during the braking period, the closing movement of the injection valve member can be braked.

[0051] Braking the closing movement of the injection valve member offers the advantage that vibrations of the injection valve member can be reduced, minimized or avoided.

[0052] In one embodiment, the gas injection valve has a mechanical damping device which is designed to dampen the movement of the injection valve member during opening and / or closing during a braking period. The mechanical damping device can comprise the spring plate and a damping chamber arranged above the spring plate. The mechanical damping device can further comprise a throttle passage, e.g. in the form of a gap or passage between a side wall of the spring plate and the

[0053] Housing or in the form of a hole in the spring plate.

[0054] The braking range can extend over part of the stroke or over the entire stroke.

[0055] Preferably, the deceleration period is shorter than the duration of the closing process of the injection valve member. In particular, the deceleration period can take place towards the end of the closing process of the injection valve member, preferably before or until the injection valve member impacts the valve sealing surface.

[0056] Braking can occur during a closing process or closing stroke and / or an opening process or opening stroke. The braking range for the braking can be shorter than the duration of the closing process or closing stroke and / or the opening process or opening stroke. Braking can occur at the beginning or at the end of the closing process or closing stroke and / or the opening process or opening stroke.

[0057] Braking can be achieved electromagnetically by a control and / or mechanically by the structure of the gas injection valve.

[0058] In one embodiment, a damping chamber is arranged on a side of the spring plate facing away from the injection valve seat, which damping chamber is designed in such a way that when the gas injection valve closes during a braking period, an overpressure occurs in the damping chamber and / or when the gas injection valve opens during a braking period, a negative pressure occurs. In particular, the overpressure can be set by a reduction in the volume of the damping chamber when the gas injection valve or the injection valve member closes. The overpressure can dampen the closing movement of the injection valve member. This can advantageously reduce, minimize or avoid vibrations of the injection valve member.

[0059] In one embodiment, a spring chamber is arranged on the side of the spring plate facing the injection valve seat, which spring chamber is connected to the fuel inlet, wherein the damping chamber can be connected to the spring chamber via a throttle passage.

[0060] As described above, the spring chamber can be connected to the fuel inlet and / or the gas chamber through at least one through-hole in a transverse wall of the housing. The throttle passage can provide pressure equalization, thus preventing excessive overpressure in the damping chamber.

[0061] In one embodiment, the gas injection valve has a plate guide sleeve for the spring plate, in which the spring plate is guided and which is arranged between the spring plate and a side wall of the housing.

[0062] In one embodiment, the spring plate is guided in the housing with a sliding fit.

[0063] In one embodiment, the spring plate has a coating on a radial side surface. The coating can provide an improved sliding fit with a suitable sealing of the damping chamber. In one embodiment, the throttle passage comprises a bore in the spring plate.

[0064] In one embodiment, the throttle passage comprises several holes in the spring plate.

[0065] If the spring plate has a cup-like shape, the hole can be formed in the bottom of the spring plate.

[0066] In one embodiment, the throttle passage comprises a gap between the spring plate and the housing.

[0067] This offers the advantage that a separately manufactured additional bore for the throttle passage is not required.

[0068] In one embodiment, a check valve is arranged in the housing, preferably at a height in the region of the spring plate, via which the damping chamber can be connected to the fuel inlet and / or the gas chamber when the gas injection valve is opened.

[0069] The check valve can compensate for any negative pressure that occurs in the damping chamber when the gas injection valve or the injection valve element opens. When the gas injection valve closes, the check valve can close, creating excess pressure in the damping chamber and dampening or slowing down the closing movement of the injection valve element.

[0070] In one embodiment, the gas injection valve has a guide sleeve which is preferably received in the gas space with a press fit and has a central guide bore through which the injection valve member is guided with a sliding fit, wherein the guide sleeve has at least one flow-through recess which is arranged at a radial distance from the central guide bore.

[0071] The guide sleeve offers the advantage that it is not necessary for the injection valve element to be guided directly over an outer surface in the housing, thus allowing the flow cross-section between the injection valve element and the housing to be increased. The at least one flow recess allows the fuel to flow through the guide sleeve, so that the flow path between the fuel inlet and the injection valve seat is maintained.

[0072] In one embodiment, the guide sleeve has a plurality of, preferably between two and ten, particularly preferably four, five, six or eight, flow-through recesses, which are preferably arranged uniformly in the horizontal circumferential direction of the guide sleeve.

[0073] With the plurality of flow recesses arranged evenly in the horizontal direction of rotation, a sufficiently large flow cross-section with reliable guidance of the injection valve member can be provided.

[0074] In one embodiment, the at least one flow-through recess is formed by a recess extending from a radial outer surface of the guide sleeve.

[0075] This offers the advantage that the flow cross-section can be increased. Alternatively, the at least one flow recess can be formed by a bore arranged in the guide sleeve.

[0076] This offers the advantage that the stability of the guide sleeve and therefore the guidance of the injection valve member can be improved.

[0077] In one embodiment, the guide sleeve has a guide bearing which is arranged between an inner surface of the central guide bore and the injection valve member.

[0078] The guide bearing takes into account the fact that gaseous fuels have inferior lubricating properties compared to diesel or gasoline. The guide bearing is preferably made of a low-friction material.

[0079] The guide bearing can be designed, for example, as a sliding coating or as a sliding sleeve.

[0080] In one embodiment, the guide bearing is made of polytetrafluoroethylene. In another variant, the guide bearing can be made of brass.

[0081] The guide bearing made of polytetrafluoroethylene (PTFE) can provide a low-friction guide for the injection valve member.

[0082] In one embodiment, the guide sleeve is made of a plastic, preferably polytetrafluoroethylene. In a variant, the guide sleeve can be made of brass. By manufacturing the guide sleeve from PTFE, a low-friction guide for the injection valve member can be provided. In particular, in such an embodiment, a separate guide bearing can be dispensed with.

[0083] In one embodiment, the injection valve member has a bulge in the region of the guide sleeve, which is guided in the central guide bore.

[0084] The bulge offers the advantage that the injection valve member can be designed with a smaller diameter in the area which is not guided in the guide sleeve, whereby the flow cross-section can be increased.

[0085] In one embodiment, the injection valve member has a bulge which has a radial outer surface which is partially interrupted in the horizontal direction of rotation and over which the bulge is guided in the housing.

[0086] This can be particularly advantageous for a configuration in which the injection valve member is guided in the housing without a guide sleeve. This can be particularly the case with small gas injection valves. The partially interrupted radial outer surface of the bulge can provide a flow cross-section between the injection valve member and the housing.

[0087] In one embodiment, the bulge has at least one flow-through recess, each of which extends from the radial outer surface of the bulge. A flow cross-section can be provided between the injection valve member and the housing by means of the at least one flow-through recess.

[0088] In one embodiment, the housing comprises a gas chamber body, an intermediate body adjoining the gas chamber body upstream of the gas chamber body, and an actuator receiving body adjoining the intermediate body upstream of the intermediate body.

[0089] List of characters

[0090] Embodiments of the invention are explained in more detail with reference to the following figures and the associated description. They show schematically:

[0091] Fig. l shows a longitudinal section through an embodiment of a gas injection valve;

[0092] Fig . 2 an enlarged view of the

[0093] Gas injection valve from Fig. l in the area of ​​the spring plate;

[0094] Fig. 2a is an enlarged view of an embodiment of a gas injection valve in the region of the spring plate in longitudinal section;

[0095] Fig. 3 is a plan view of an embodiment of a

[0096] spring plate;

[0097] Fig. 4 is an enlarged view of an embodiment of a gas injection valve in the region of the spring plate in longitudinal section; Fig. 4a is an enlarged view of an embodiment of a gas injection valve in the region of the side wall of the spring plate;

[0098] Fig. 5 is an enlarged view of an embodiment of a gas injection valve in the region of the spring plate in longitudinal section;

[0099] Fig . 6 an enlarged view of the

[0100] Gas injection valve from Fig . l in the area of ​​the guide sleeve ;

[0101] Fig. 7 is a plan view of an embodiment of a guide sleeve;

[0102] Fig. 8 is a cross-sectional view of an embodiment of a guide sleeve with an injection valve member, which is received in a central guide bore;

[0103] Fig. 9 shows a longitudinal section through an embodiment of a gas injection valve without a guide sleeve;

[0104] Fig. 10 is a cross-sectional view of an embodiment of an injection valve member;

[0105] Description of exemplary embodiments

[0106] In the description of the figures, corresponding

[0107] The same reference numerals are used for parts of the embodiments. Figure 1 shows a longitudinal section through an embodiment of a gas injection valve 10 for injecting or blowing in gaseous fuel into the combustion chamber of an internal combustion engine. The gas injection valve 10 or gas injection valve has a housing 11 extending along a longitudinal axis L, which housing has a laterally arranged fuel inlet 24 and an injection valve seat 26 with a valve sealing surface 131 opening outwards, i.e. towards the combustion chamber of the internal combustion engine. The valve sealing surface 131 opening outwards can provide a sufficient flow cross-section for the gaseous fuel into the combustion chamber. A gas chamber 25 runs from the fuel inlet 24 to the injection valve seat 26. The housing 11 comprises an actuator receiving body 14, an intermediate body 12 and a gas space body 13.The outwardly opening valve sealing surface 131 is formed at a lower, downstream end of the gas chamber body 13.

[0108] In a variant not shown in the figures, a cap is arranged at the downstream end of the gas chamber body 13 and is fastened to the gas chamber body 13 and has a blind hole and at least one injection bore aligned into the combustion chamber of the internal combustion engine. The gaseous fuel can thus reach the blind hole of the cap after the outwardly opening valve sealing surface 131 and from there into the combustion chamber of the internal combustion engine in a direction dependent on the alignment of the at least one injection bore of the cap.

[0109] Internal combustion engine flow. The gas injection valve 10 has an injection valve member 31 arranged so as to be adjustable or movable along the longitudinal axis L. The injection valve member 31 has a conical end piece 311 at a lower, downstream end, which is designed to interact with the injection valve seat 26. The conical end piece 311 has, in particular, a conical valve member sealing surface, which is designed to interact in a sealing manner with the valve sealing surface 131.

[0110] A compression spring 51 is arranged in the intermediate body 12, which is supported at a first, downstream end relative to the housing 11 in a fixed position on the housing 11 and at a second, upstream end on a spring plate 52 and applies a closing force to the valve sealing surface 131 of the injection valve member 31. The spring plate 52 is attached to the injection valve member 31 at an upper end region of the injection valve member 31 facing away from the injection valve seat 26 and is adjustable together with the injection valve member 31 along the longitudinal axis L.

[0111] The fuel inlet 24 is in a side wall of the housing

[0112] 11 is arranged at a height between the compression spring 51 and the injection valve seat 26.

[0113] In the actuator receiving body 14 and partly in the intermediate body

[0114] 12, an electromagnetically actuated actuator arrangement 41 with an electromagnet 411 is arranged, which is designed to adjust the injection valve member 31 along the longitudinal axis L. By activating the actuator arrangement 41, i.e. by energizing the electromagnet 411, the injection valve member 31 can be moved downwards, in the direction of the injection valve seat 26, so that the gas injection valve 10 or the injection valve member 31 opens and the gaseous fuel can flow from the gas chamber 25 into the combustion chamber. By deactivating the actuator arrangement 41, i.e. by interrupting the energization of the electromagnet 411, the injection valve member 31 can be adjusted upwards, in the direction away from the injection valve seat 26, so that the gas injection valve 10 or the injection valve member 31 opens. the injection valve member 31 closes in that the conical end piece 311 with its valve member sealing surface lies sealingly against the valve sealing surface 131.

[0115] Figure 2 shows an enlarged view of the gas injection valve 10 from Figure 1 in the area of ​​the spring plate 52. A central recess 521 is formed in the spring plate 52, through which recess the injection valve member 31 is passed with a sliding fit. The spring plate 52 has a cup-like shape with a base 522 and a circumferential side wall 523 which extends from the base 522 in the direction of the injection valve seat. The upstream, second end and a part of the compression spring 51 adjoining the second end are accommodated in the spring plate 52, the compression spring 51 pressing with the second end against the base 522 of the spring plate 52 and thus applying a closing force to the injection valve member 31 on the injection valve seat. The housing or. the intermediate body 12 has a cup-shaped compression spring seat 123, via which the downstream, first end of the compression spring 51 is fixedly positioned on the housing or intermediate body 12 relative to the housing.Intermediate body 12 is supported and in which the first end and a part of the compression spring 51 adjoining the first end are received. The compression spring seat 123 has a central recess through which the injection valve member 31 projects. In one variant, the gas injection valve 10 can be designed without a compression spring seat 123. The compression spring 51 can then be supported at the first end, e.g. on a shoulder 1211 of the intermediate body 12, in a fixed position relative to the housing.

[0116] The compression spring 51 is arranged in a spring chamber 121 formed in the intermediate body 12, which is connected to the fuel inlet 24 and the gas chamber 25. Above the spring plate 52, a chamber 126 is formed, which is connected to the spring chamber 121 via a circumferential gap between the side wall 523 of the spring plate 52 and an inner surface of the intermediate body 12. The gap therefore forms a passage which connects the spring chamber 121 to the chamber 126 and provides immediate pressure equalization both when the injection valve member 31 opens and closes.

[0117] The housing or intermediate body 12 has a stop shoulder 124 with an annular stop surface 1241, which forms a stroke stop for the flat stop surface 524 of the spring plate 52. The annular stop surface 524 of the spring plate 52 is formed by the end of the side wall 523 of the spring plate 52 facing the injection valve seat.

[0118] A threaded cap 53 is screwed onto the upper end region 312 of the injection valve member 31, facing away from the injection valve seat. The compression spring 51 presses the spring plate 52 against a contact surface 531 of the threaded cap 53, which faces the injection valve seat. The threaded cap 53 can be used to adjust the axial position of the spring plate 52 relative to the injection valve member 31, so that the maximum stroke of the spring plate 52 or of the injection valve member 31 between closing the gas injection valve 10 and fully opening the gas injection valve 10 can be adjusted via the axial position of the spring plate 52 relative to the injection valve member 31, which position is adjusted by the threaded cap 53.

[0119] A stroke adjusting disc 54 made of metal is arranged between the bottom surface of the threaded cap 53 facing the injection valve seat and the end surface of the injection valve member 31 facing away from the injection valve seat. The stroke adjusting disc 54 can be made of hardened steel, for example. The stroke adjusting disc 54 adjusts the screw-in depth or screw depth of the threaded cap 53 onto the injection valve member 31, so that the maximum stroke of the spring plate 52 or of the injection valve member 31 is adjusted via the adjustable screw-in depth.

[0120] Above the threaded cap 53, a tappet 412 of the electromagnetic actuator arrangement, which tappet is adjustable along the longitudinal axis, abuts the threaded cap 53. The threaded cap 53 and the injection valve member 31 can be adjusted along the longitudinal axis via the tappet 412. By activating the electromagnetic actuator arrangement, the tappet 412 can be adjusted in the direction of the injection valve seat. By deactivating the electromagnetic actuator arrangement, the tappet 412 can be moved in the direction facing away from the injection valve seat.

[0121] Direction can be adjusted. Figure 2a shows an enlarged view of an embodiment of a gas injection valve 10 in the region of the spring plate 52. The intermediate body 12 has a transverse wall 122 with a central bore through which the injection valve member 31 is passed. A guide sleeve 1222 is arranged in the bore, through which the injection valve member 31 is passed with a sliding fit. The transverse wall 122 has a through-bore 1221 through which the spring chamber 121 is connected to the gas chamber 25. Pressure oscillations occurring in the gas chamber 25 are dampened as they pass through the through-bore 1221, so that their propagation into the spring chamber 121 is reduced, minimized or prevented.

[0122] In a variant not shown, the injection valve member 31 can be guided in a larger guide sleeve 1222 with a clearance, so that the passage bore

[0123] 1221 can be dispensed with. In another variant not shown, the transverse wall 122 can not be provided with a guide sleeve

[0124] 1222, so that the injection valve member 31 is guided directly through the central bore. The injection valve member 31 can then be guided through the central bore with a sliding fit, wherein the transverse wall has a through-bore 1221, or can be guided through the central bore with a clearance, wherein the transverse wall has no through-bore. In a further variant, the injection valve member 31 can be guided through the guide sleeve 1222 or the central bore of the transverse wall 122 with a clearance, and the transverse wall 122 can have a

[0125] Have a through hole 1221. Figure 3 shows a plan view of an embodiment of a spring plate 52 of an embodiment of a gas injection valve. The central recess 521 of the spring plate 52 has two parallel spring plate chamfers 5211. The injection valve member, not shown in Figure 3, in this embodiment has two valve member chamfers which are arranged parallel to the spring plate chamfers 5211. Due to the spring plate chamfers 5211 and the valve member chamfers, a torque can be applied to the injection valve member via the spring plate 52. On the top side of the spring plate 52, three blind holes 526 are formed, via which the spring plate 52 can be held with a tool so that the threaded cap can be screwed on tightly. In one variant, through holes can be formed instead of the blind holes.

[0126] Figure 4 shows an enlarged view of a further embodiment of a gas injection valve 10 in the region of the spring plate 52. A damping chamber 126 is formed above the spring plate 52, which dampens the opening movement and / or the closing movement of the injection valve member 31. The spring plate 52 is guided with a sliding fit in the housing or intermediate body 12. A bore 525 is formed in the base 522 of the spring plate 52. The bore 525 forms a throttle passage which connects the spring chamber 121 to the damping chamber 126. Any overpressure or underpressure building up in the damping chamber 126 can therefore be gradually reduced via the bore 525.

[0127] In one variant, the spring plate 52 can have a coating on the radial outer surface of the side wall 523 to minimize friction. In another variant, a plate guide sleeve can be arranged between the side wall 523 and the

[0128] Intermediate body 12 may be arranged in which the spring plate 52 is guided.

[0129] In a further variant, a gap 125 can be formed between the side wall 523 of the spring plate 52 and an inner surface of the intermediate body 12, alternatively or in addition to the bore 525, which forms a throttle passage via which the damping chamber 126 is connected to the spring chamber 121.

[0130] In Figure 4, the cross wall 122 with the through-bore 1221 is shown as a variant in dashed lines. The variant with the cross wall and one or more through-bores in the cross wall as well as the guide sleeve is also conceivable in the embodiments shown in Figures 1, 2 or 5.

[0131] Figure 4a shows an enlarged view of an embodiment of a gas injection valve in the region of the side wall 523 of the spring plate 52 and its stop surface 524 as well as the stop shoulder 124 of the intermediate body 12. For the purpose of a simplified representation, the compression spring, which is arranged below the spring plate 52 in the spring chamber 121, is not shown in Figure 4a. The side wall 523 of the spring plate 52 has a profile with a first recess 5231 and a second, smaller recess 5232. Through the gap between the side wall 523 of the spring plate 52 and the inner surface 1212 of the intermediate body 12 or. A throttle passage 125 is formed in the passage formed by the second recess 5232, with which a gradual pressure equalization between the damping chamber 126 and the spring chamber 121 can be provided during an opening movement and / or a closing movement of the injection valve member.

[0132] Figure 5 shows an enlarged view of a further embodiment of a gas injection valve 10 in the region of the spring plate 52. A check valve 127 is arranged in the intermediate body 12 at a height in the region of the spring plate 52. Via the check valve 127, the damping chamber 126 can be connected to the fuel inlet 24 and the gas chamber 25 when the gas injection valve is opened when a negative pressure builds up in the damping chamber 126, so that the negative pressure in the damping chamber 126 can be reduced through the passage 128, whereby the opening movement of the injection valve member 31 can take place faster than its closing movement.

[0133] Figure 6 shows an enlarged view of the gas injection valve 10 from Fig. 1 in the area of ​​the guide sleeve 61. The guide sleeve 61 is received in the gas chamber 25 with a press fit and has a central guide bore through which the injection valve member 31 is guided with a sliding fit. The injection valve member 31 has a bulge 313 in the area of ​​the guide sleeve 61, which is received in the guide sleeve 61 with a sliding fit. The guide sleeve 61 has a plurality of flow bores 611 which are arranged radially spaced from the central guide bore. The guide sleeve 61 has a guide bearing 612 which is arranged between an inner surface of the central guide bore and the injection valve member 31 or the bulge 313. The guide bearing 612 is designed as a sliding sleeve and is made, for example, from PTFE. In one variant, the sliding sleeve can be made of brass.

[0134] Figure 7 shows a plan view of an embodiment of a guide sleeve 61. A guide bearing is not shown in Figure 7, but could be arranged in the form of a sliding sleeve or a sliding coating on the central guide bore 613. The guide sleeve has eight flow-through recesses 611 in the form of flow-through bores, which are arranged evenly in the horizontal circumferential direction of the guide sleeve 61.

[0135] Figure 8 shows an illustration of an embodiment of a guide sleeve 61 with an injection valve member 31 in a horizontal cross-section. The injection valve member 31 is received in the central guide bore 613. A guide bearing in the form of a sliding sleeve or a sliding coating can be arranged between the injection valve member 31 and an inner surface of the central guide bore 613 (not shown). The guide sleeve 61 has four flow-through recesses 611 arranged evenly in the horizontal circumferential direction of the guide sleeve 61. The flow-through recesses 611 are each formed by a recess 611 extending from a radial outer surface 614 of the guide sleeve 61. The continuation of the radial outer surface 614 of the guide sleeve 61 in the region of the flow-through recesses 611 is indicated by the dashed line K1.

[0136] Figure 9 shows a representation of an embodiment of a

[0137] Gas injection valve 10 without guide sleeve. The gas chamber 25 has a first gas chamber section 251 and a second gas chamber section 252, the first gas chamber section 251 having a larger horizontal diameter than the second gas chamber section 252. The first gas chamber section 251 and the second gas chamber section 252 are connected to one another via a conical section which is formed by a conical inner surface 132 of the gas chamber body 13. The injection valve member 31 is guided via a bulge 313 in the second gas chamber section 252 on an inner surface 133 of the gas chamber body 13. The bulge 313 has a radial outer surface which is partially interrupted in the horizontal circumferential direction and is partially interrupted due to recesses 314 in the bulge 313. Due to the partially interrupted radial outer surface or .The recesses 314 allow the fuel to flow through the second gas chamber section 252 to the injection valve seat 26. This becomes more clearly apparent in connection with the embodiment of an injection valve member shown in Figure 10. In Figure 9, the housing has a transverse wall between the gas chamber and the spring chamber, as shown in Figure 2a. It is also conceivable to dispense with the transverse wall in an embodiment of the fuel injection valve 10 according to Figure 9, as is shown, for example, in Figure 1.

[0138] Figure 10 shows an embodiment of an injection valve member 31 in a horizontal cross section. The injection valve member 31 could, for example, be used in the embodiment of the gas injection valve shown in Figure 9. The injection valve member 31 has three flow-through recesses 314 in the region of the bulge 313, each of which extends from the radial outer surface 3131 of the bulge 313, which is partially interrupted in the circumferential direction. The continuation of the radial outer surface 3131 of the bulge 313 in the region of the flow-through recesses 314 is indicated by the dashed line K2. The injection valve member 31 can be connected via the outer surface 3131 to an inner surface of a second gas space section of a gas space body, such as, for example, a shown in Figure 9, wherein the fuel can flow through the flow-through recesses 314.

Claims

Patent claims 1. Gas injection valve (10) for injecting gaseous fuel into the combustion chamber of a Internal combustion engine, comprising a housing (11) extending along a longitudinal axis (L), which has a fuel inlet (24) and an injection valve seat (26) with an outwardly opening valve sealing surface (131), a gas chamber (25) arranged in the housing, which runs from the fuel inlet to the injection valve seat, an injection valve member (31) arranged so as to be adjustable along the longitudinal axis, which is designed to cooperate with the injection valve seat, a compression spring (51) which applies a closing force to the valve sealing surface of the injection valve member, an electromagnetically actuated actuator arrangement (41) for adjusting the injection valve member along the longitudinal axis, an end region of the injection valve member facing away from the injection valve seat on the Injection valve member mounted spring plate (52), wherein the compression spring is supported at a first end relative to the housing in a fixed position on the housing and at a second end on the spring plate, wherein the housing has a stop shoulder (124) which forms a stroke stop for a stop surface (524) of the spring plate facing the injection valve seat.

2. Gas injection valve (10) according to claim 1, characterized in that the spring plate (52) has a central recess (521) through which the injection valve member (31) is passed.

3. Gas injection valve (10) according to claim 2, characterized in that the injection valve member (31) in the region of the spring plate (52) has a chamfered, circular cross-section with at least one valve member chamfer.

4. Gas injection valve (10) according to claim 3, characterized in that the central recess (521) has a spring plate chamfer (5211) which is arranged parallel to the valve member chamfer.

5. Gas injection valve (10) according to one of the preceding claims, characterized in that the gas injection valve has a threaded cap (53) which can be screwed onto the injection valve member via a thread formed on the injection valve member in the end region (312) of the injection valve member (31) facing away from the injection valve seat (26) in such a way that the compression spring (51) presses the spring plate (52) against a contact surface (531) of the threaded cap facing the injection valve seat.

6. Gas injection valve (10) according to claim 5, characterized in that a stroke adjusting disc (54) is arranged between a bottom surface of the threaded cap (53) facing the injection valve seat (26) and an end surface of the injection valve member facing away from the injection valve seat.

7. Gas injection valve (10) according to one of claims 5 to 6, characterized in that the gas injection valve has a tappet (412) which is adjustable along the longitudinal axis (L) by the electromagnetically actuated actuator arrangement (41), which tappet abuts with an end surface facing the injection valve seat (26) against a bottom surface of the threaded cap (53) facing away from the injection valve seat.

8. Gas injection valve (10) according to one of the preceding claims, characterized in that the stop shoulder (124) has an annular stop surface (1241).

9. Gas injection valve (10) according to one of the preceding claims, characterized in that the spring plate (52) has a cup-like shape with a bottom (522) and a circumferential side wall (523), wherein the side wall extends from the bottom in the direction of the injection valve seat (26) in such a way that the second end and a part of the compression spring (51) adjoining the second end can be received in the spring plate.

10. Gas injection valve (10) according to claim 9, characterized in that the stop surface (524) of the spring plate (52) is formed by a facing end (524) of the side wall (523) of the spring plate is formed.

11. Gas injection valve (10) according to one of the preceding claims, characterized in that the housing (11) has a cup-shaped compression spring seat (123) which is designed to receive the first end and a part of the compression spring (51) adjoining the first end.

12. Gas injection valve (10) according to one of the preceding claims, characterized in that the fuel inlet (24) is arranged in a side wall of the housing (11) at a height between the compression spring (51) and the injection valve seat (26).

13. Gas injection valve (10) according to one of the preceding claims, characterized in that the gas injection valve has a control which is designed to electromagnetically activate the actuator arrangement (41) when closing the gas injection valve during a braking period.

14. Gas injection valve (10) according to one of the preceding claims, characterized in that the gas injection valve has a mechanical damping device (125, 126, 52, 5232, 127) which is designed to dampen the movement of the injection valve member (31) during opening and / or closing during a braking period.

15. Gas injection valve (10) according to one of the preceding claims, characterized in that on a On the side of the spring plate (52) facing away from the injection valve seat (26), a damping chamber (126) is arranged, which is designed such that when the gas injection valve is closed during a braking period, an overpressure occurs in the damping chamber and / or when the gas injection valve is opened during a braking period, a negative pressure occurs.

16. Gas injection valve (10) according to claim 15, characterized in that on the side of the spring plate (52) facing the injection valve seat (26) there is arranged a spring chamber (121) which is connected to the fuel inlet (24), wherein the damping chamber (126) is connectable to the spring chamber via a throttle passage (525, 125, 5232).

17. Gas injection valve (10) according to claim 16, characterized in that the throttle passage comprises a bore (525) in the spring plate.

18. Gas injection valve (10) according to claim 16 or 17, characterized in that the throttle passage comprises a gap (125, 5232) between the spring plate and the housing.

19. Gas injection valve (10) according to one of claims 15 to 18, characterized in that a check valve (127) is arranged in the housing (11), preferably at a height in the region of the spring plate (52), via which check valve the damping chamber (126) can be connected to the fuel inlet (24) and / or the gas chamber (25) when the gas injection valve is opened.

20. Gas injection valve (10) according to one of the preceding claims, characterized in that the gas injection valve has a guide sleeve (61) which is preferably received in a press fit in the gas space (25) and has a central guide bore (613) through which the injection valve member (31) is guided in a sliding fit, wherein the guide sleeve has at least one flow-through recess (611) which is arranged radially spaced from the central guide bore.

21. Gas injection valve (10) according to claim 20, characterized in that the guide sleeve (61) has a plurality of, preferably between two and ten, particularly preferably four, five, six or eight, flow-through recesses (611), which are preferably arranged uniformly in the horizontal circumferential direction of the guide sleeve.

22. Gas injection valve (10) according to claim 20 or 21, characterized in that the at least one flow-through recess (611) is formed by a recess extending from a radial outer surface (614) of the guide sleeve (61).

23. Gas injection valve (10) according to claim 20 or 21, characterized in that the at least one flow-through recess (611) is formed by a bore arranged in the guide sleeve (61).

24. Gas injection valve (10) according to one of claims 20 to 23, characterized in that the guide sleeve (61) has a guide bearing (612) which is arranged between a inner surface of the central guide bore (613) and the injection valve member (31).

25. Gas injection valve (10) according to claim 24, characterized in that the guide bearing (612) is designed as Sliding coating is formed.

26. Gas injection valve (10) according to claim 24, characterized in that the guide bearing (612) is designed as sliding sleeve is formed.

27. Gas injection valve (10) according to one of claims 24 to 26, characterized in that the guide bearing (612) is made of polytetrafluoroethylene or brass.

28. Gas injection valve (10) according to one of claims 20 to 27, characterized in that the guide sleeve (61) is made of a plastic, preferably of polytetrafluoroethylene or brass.

29. Gas injection valve (10) according to one of claims 20 to 28, characterized in that the injection valve member (31) has a bulge (313) in the region of the guide sleeve (61) which is guided in the central guide bore (613).

30. Gas injection valve (10) according to one of the preceding claims, characterized in that the injection valve member (31) has a bulge (313) which has a radial outer surface (3131) which is partially interrupted in the horizontal circumferential direction and over which the bulge is guided in the housing (11).

31. Gas injection valve (10) according to claim 30, characterized in that the bulge (313) has at least one flow-through recess (314) which in each case extends from the radial outer surface (3131) of the bulge.

32. Gas injection valve (10) according to one of the preceding Claims, characterized in that the housing (11) comprises a gas chamber body (13), an upstream of the Gas chamber body adjoining the gas chamber body intermediate body (12) and an upstream of the Intermediate body adjoining the intermediate body Actuator receiving body (14).

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