Injector for feeding gaseous fuel into, in particular direct injection into, the combustion chamber of an internal combustion engine and gas engine

Abstract

The invention relates to an injector (24) for feeding gaseous fuel into a combustion chamber (22), the injector having a housing (26) through which fuel can flow, the housing having a flow outlet (28) through which fuel can be fed out of the housing (26) for feeding the fuel into the combustion chamber (22), the injector further having a valve seat (30) and a valve element (38) which is movable between a closed position and an open position. In the closed position, the valve element (38) rests on the valve seat (30) such that a first housing region (42) through which fuel can flow is separated from a second housing region (44) through which fuel can flow. In the open position, the housing regions (42, 44) are in flow communication with one another such that fuel flowing through the housing regions (42, 44) can be fed out of the housing (26) via the flow outlet (28). The valve element (38) opens outwards and comprises a raised and / or constricted valve body portion (50) which is arranged in the second housing region (44).

Description

Technical Field

[0001] This invention relates to an injector for delivering gaseous fuel, particularly by direct injection, into the combustion chamber of an internal combustion engine, according to the preamble of claim 1. The invention also relates to a gas engine having at least one such injector. Background Technology

[0002] DE 10 2017 213 737 A1 discloses an injector for injecting gaseous fuel into the combustion chamber of an internal combustion engine, having a nozzle body in which a pressure chamber is formed, which can be filled with gaseous fuel under injection pressure, and from which the nozzle extends, through which the gaseous fuel can flow out. Additionally, EP 1 195 203 A2 discloses a device for atomizing a liquid medium. Summary of the Invention

[0003] The object of the present invention is to provide an injector for an internal combustion engine and a gas engine having at least one such injector, so that gaseous fuel can be advantageously delivered into the combustion chamber of the internal combustion engine or gas engine by means of the injector.

[0004] This task is accomplished by an injector having the features of claim 1 and a gas engine having the features of claim 10. Advantageous designs with suitable inventive improvements are described in the dependent claims.

[0005] The first aspect of the invention relates to an injector for delivering gaseous fuel, particularly hydrogen, into the combustion chamber of an internal combustion engine, particularly a motor vehicle, particularly by direct injection. Thus, the internal combustion engine can operate with the aid of gaseous fuel in its ignition mode, and is therefore a gas engine, particularly according to the principle of an externally ignited engine, or also referred to as a gas engine. During the ignition operation of the internal combustion engine, for example in each working cycle of the internal combustion engine, gaseous fuel is delivered into, particularly by direct injection, the combustion chamber by means of the injector. For this purpose, the injector includes a housing through which the gaseous fuel can flow. This specifically means that the gaseous fuel is delivered into or can be delivered into the housing and thus into the injector, particularly from outside the housing or generally from outside the injector, and subsequently delivered or can be delivered out of the housing and particularly generally from the injector. For example, the gaseous fuel is delivered into the injector, particularly the housing, through at least one inlet. "Delivering gaseous fuel from the housing or generally from the injector" is also referred to as "exhausting gaseous fuel from the housing or generally from the injector." For this purpose, the casing has at least one or more outlets through which gaseous fuel flowing through the casing can pass, through which the gaseous fuel can be delivered from the casing, and more generally from the injector, and thus, for example, delivered into the environment of the casing, and more generally the injector, to deliver the gaseous fuel into the combustion chamber. In other words, in order to deliver the gaseous fuel into the combustion chamber, and more particularly, to directly inject the gaseous fuel into the combustion chamber, the gaseous fuel initially introduced into the casing or the injector is drawn out or delivered from the casing, and more generally from the injector, via the outlet, also called the outlet, and thus delivered into, i.e., injected into, the environment, and more particularly directly into the combustion chamber. In other words, the gaseous fuel flowing through the outlet flows out from the casing, and more generally from the injector, so that the injector itself sprays or blows out the gaseous fuel flowing through the outlet and thus, for example, directly injects it into the combustion chamber.

[0006] The injector, particularly the housing, also has a valve seat, which is formed, for example, particularly directly from the housing, particularly housing components. Furthermore, the injector has a valve element, also simply referred to as a valve, which is movable relative to the housing and relative to the valve seat in the direction of movement, at least or only translationally, between a closed position and at least one open position. The closed position is a first position of the valve element. In other words, the closed position is also referred to as the first position. The open position is a second position of the valve element. In other words, the open position is also referred to as the second position. This direction of movement preferably extends parallel to the longitudinal extension direction of the valve element and / or the housing. The feature that "the valve element is movable relative to the housing and relative to the valve seat in the direction of movement between the positions" specifically refers to the fact that the valve element can move back and forth between the positions relative to the housing and relative to the valve seat in the direction of movement.

[0007] In the closed position, the valve rests on the valve seat. In other words, the valve rests against the valve seat in the closed position, thereby separating, by means of the valve rest, a first housing region through which gaseous fuel can flow from the housing and a second housing region downstream of the first housing region, which is also through which gaseous fuel can flow in the direction of gaseous fuel flow through the housing. Here, the second housing region includes an outlet. This means that gaseous fuel first flows through the first housing region in its path through the housing and thus, for example, from the inlet to the outlet and through the outlet, and then through the second housing region and the outlet, which, for example, opens into the second housing region at one end and into or to the environment of the housing, and especially the entire injector, at the other end. In the fully manufactured state of the internal combustion engine, for example, this outlet opens directly into the combustion chamber at the other end, so that the gaseous fuel flowing through the outlet and thus out of the injector is directly injected into the combustion chamber.

[0008] For example, the valve seat extends particularly around the overflow port circumferentially, especially in the direction of movement of the housing or respective housing regions, which is closed and thus locked by means of the valve in the closed position. Thus, in the closed position, the valve isolates the flow in the housing region, preventing gaseous fuel from flowing from the first housing region into the second housing region. Therefore, no gaseous fuel flows through the outlet in the closed position, meaning the injector does not supply gaseous fuel, i.e., does not eject gaseous fuel. In other words, because the valve isolates the flow in the housing region in the closed position, gaseous fuel is prevented from flowing out of the housing via the outlet, and especially from flowing out of the injector in general. Because these housing regions are isolated by means of the valve in the closed position, the outlet is isolated from the first housing region, especially by means of the valve. Therefore, gaseous fuel cannot flow from the first housing region to the outlet and cannot flow through the outlet.

[0009] In the open position, the valve is spaced apart from or raised from the valve seat, thereby allowing gaseous fuel flowing through and connected to the housing area, particularly via the flow port, to be discharged from the housing, and especially from the injector in general, via the outlet. In other words, to deliver gaseous fuel into the combustion chamber, particularly into the direct injection combustion chamber, the valve is moved from the closed position to the open position. Thus, gaseous fuel can flow from the first housing area into the second housing area, through the second housing area, and therefore, particularly through the outlet, so that the injector sprays or is able to spray gaseous fuel in the open position.

[0010] In order to advantageously, and particularly advantageously, to flowably supply, i.e., inject gaseous fuel and deliver it into the combustion chamber using an injector, the present invention specifies that the valve member is at least partially movable into the second housing region when it moves from the closed position to the open position. In other words, it is specified that the valve member moves at least partially into the second housing region when it moves from the closed position to the open position. Furthermore, for the valve member to move from the closed position to the open position, the valve member moves relative to the housing and therefore relative to the valve seat at least or only translationally along an opening direction extending parallel to the direction of movement, specifically from the first housing region to the second housing region. Because at least a portion of the valve member moves into the second housing region when it moves from the closed position to the open position, at least said portion of the valve member moves out of the second housing region when it moves from the open position to the closed position. Because the valve member moves into the second housing region when it moves from the closed position to the open position, the valve member is also referred to as an outwardly opening valve member, and thus the injector is referred to as an outwardly opening injector or A-nozzle or A-injector.

[0011] Furthermore, the present invention specifies that the valve has a valve body portion that is located in and thus protrudes into the second housing region in both positions, namely the closed and open positions. This valve body portion narrows, at least in a localized area, in a direction away from the valve seat, particularly in the aforementioned opening direction, in a conical or truncated conical shape. Alternatively or additionally, the valve body portion is raised / arched at least in a localized area. The valve body portion is therefore a flow guide or flow-guiding geometry, thereby advantageously, particularly advantageously, guiding the flow of gaseous fuel in the open position through the housing region and the outlet. For example, in its path from the first housing region to the second housing region and through the outlet, the gaseous fuel flowing through the housing region and thus through the outlet in the open position flows at least toward and / or at least around and / or at least along the localized area of ​​the valve body portion, thereby influencing the flow of gaseous fuel in terms of its flow. Because the valve body is now designed, at least in that local area, to be narrowed and / or raised in that local area, the valve body advantageously influences the flow of gaseous fuel, i.e., its flow.

[0012] For example, the second housing region is at least partially, and especially at least primarily or entirely, directly defined or formed by, for example, an integral housing region of the housing, wherein the housing member is, for example, a so-called vent cap or vent cap area of ​​the housing. Therefore, the valve member moves at least partially into the vent cap or vent cap area when it moves from the closed position to the open position. When vent cap is mentioned below, it also refers to the vent cap area (unless otherwise stated), and vice versa. Here, the invention is based particularly on the following understanding and considerations:

[0013] Hydrogen, as a gaseous fuel, has a lower density than air and therefore mixes poorly within the combustion chamber. To achieve a favorable mixture formation, especially when hydrogen is directly injected into the combustion chamber, it is generally desirable or advantageous to intentionally generate a tumbling flow and / or turbulence of the gaseous fuel, such as in the form of hydrogen, flowing into the combustion chamber, particularly when using injection pulses and combining the so-called jet stream with the interaction of the internal combustion engine combustion chamber walls, which directly define the combustion chamber. The aforementioned jet stream specifically means that, in the open position of the valve, the injector sprays gaseous fuel in a manner that forms at least one fuel jet, which is the aforementioned jet stream. Especially in the open position of the valve, particularly when multiple outlets are provided, the injector sprays gaseous fuel in the form of multiple fuel jets, also called jet streams. It is also advantageous to increase the pulse when a perforated cap is centrally located in the combustion chamber. In other words, the gaseous fuel flowing through the outlets and thus exiting from the casing, and especially from the injector in general, via the outlets forms the aforementioned jet stream, also called a jet or fuel jet. The first combustion chamber wall mentioned above is, for example, a cylinder wall that directly defines the cylinder of an internal combustion engine. The cylinder wall is, for example, formed by the cylinder block of the internal combustion engine, particularly designed as a cylinder crankshaft housing. The second combustion chamber wall is, for example, formed by a piston, which is movably disposed within the cylinder. For example, the second combustion chamber wall is the piston recess of the piston.

[0014] Furthermore, advantageous mixture formation can be achieved by using multiple outlets, also known as blowholes, and thus uniform air intake. It is advantageous here to maximize the single jet pulse to obtain a sufficiently large jet penetration depth. This is particularly ensured by the valve body design according to the invention due to reduced flow losses.

[0015] The air cap is a flow zone arranged below a valve, also known as an injection valve, with respect to its opening direction, and particularly through the outlet, allows the gaseous fuel flowing through the outlet to exhibit a favorable flow, such as a favorable tumbling flow and / or turbulence. Typically, outwardly opening valves are designed as simple lift valves / mushroom valves, with their valve bodies designed as simple valve discs. In contrast, the present invention specifies a particularly advantageous structural configuration for the valve, and especially the valve body, in which the so-called air cap volume can be kept very small through the valve body design of the present invention. The air cap volume refers to, for example, the entire volume or internal volume of the second housing region, especially excluding the outlet. Because the air cap volume can be kept very small in the present invention, undesirable loss volumes can be reduced compared to conventional solutions, flow losses can be mitigated, and undesirable self-ignition in the air cap, i.e., the second housing region, can be prevented. Furthermore, the present invention allows for the adjustment of a very favorable jet direction of the injection flow.

[0016] In principle, it is conceivable, especially in injectors used for direct hydrogen injection, to design the valve as an inwardly opening valve, and thus an inwardly opening needle valve. Here, the valve moves away from the second housing region and thus at least partially into the first housing region as it moves from the closed position to the open position. The valve seat would then be located at one end of the air cap. However, this could lead to sealing problems due to the thermal boundary conditions within the combustion chamber, especially during internal combustion engine ignition operation, which can be avoided by designing the valve as an outwardly opening valve according to the invention. If the valve is designed as a simple outwardly opening lift valve, omitting the second housing region so that the combustion chamber side end of the lift valve is directly placed within the combustion chamber and not surrounded by the air cap, the injector produces a jet flow in the form of an umbrella jet, which is unsuitable for generating favorable tumbling and / or turbulence of the gaseous fuel constituting the jet flow. Furthermore, a simple lift valve introduces flow losses in the air cap, thus failing to guarantee the directional constancy of the jet.

[0017] The aforementioned problems and disadvantages can now be avoided by the present invention, because at least a local area of ​​the valve body acts as an advantageous flow-guiding geometry, which advantageously and facilitatingly guides the flow of gaseous fuel through the housing area and thus through the outlet, or advantageously influences the flow of the gaseous fuel.

[0018] With the valve body design according to the invention, the valve body or valve element can occupy a large portion of the internal volume of the wind cap or second housing area, especially in its open position, thereby reducing the wind cap volume compared to conventional solutions. This reduces the risk of self-ignition and minimizes loss volume.

[0019] By means of the valve body, the gaseous fuel flowing through the second local region, i.e., its flow, can be advantageously guided, especially in the second housing region. In other words, at least a local region of the valve body has a very advantageous shape, also known as a valve shape, thereby advantageously guiding the gaseous fuel or its flow in the second housing region. In particular, excessive dead space and excessive vortex formation can be prevented. This can maintain very small flow losses in the air cap (i.e., in the second housing region) and avoid the influence when using multiple overflow ports or overflow orifices. As a result, a particularly high fuel jet pulse can be achieved, thereby exhibiting a very favorable mixture formation. Overflow ports or overflow orifices refer in particular to the aforementioned outlet. Furthermore, the invention allows for a prescribed flow at the overflow ports or overflow orifices, which results in a very advantageous and prescribed jet direction of the gaseous fuel flowing from the housing, especially generally from the injector. Thus, a favorable tumbling flow and / or turbulence of the gaseous fuel flowing from the housing or generally from the injector toward the combustion chamber can be achieved. This can thereby achieve improved mixture homogenization compared to conventional solutions, thereby achieving a particularly high specific power of the internal combustion engine. In addition, it can enable the operation of internal combustion engines with very low emissions.

[0020] In a particularly advantageous embodiment of the invention, the valve body portion, in the closed position of the valve, occupies at least one-third, and especially at least half, of the aforementioned and described internal volume of the second housing region, and in the closed position of the valve, it occupies an internal volume through which gaseous fuel can flow. Thus, the volume of the wind cap that does not receive the valve in the open position can be kept very small, thereby keeping the loss volume within a very small range.

[0021] Another embodiment is characterized by the valve body being configured with rotational symmetry about a central axis extending parallel to the direction of movement. This allows gaseous fuel flowing through the housing region to be guided in a particularly favorable flow manner via the valve body.

[0022] In other particularly advantageous designs of the invention, the valve body portion is convex, at least in that local area and particularly at least primarily, and thus protrudes into the second housing region. This ensures particularly favorable flow guidance of gaseous fuel.

[0023] In order to particularly advantageously guide gaseous fuel and thus deliver it into, and especially inject it into, the combustion chamber, other designs of the invention specify that the valve body is designed, at least in that local area, and particularly at least primarily or entirely, in a truncated spherical shape. In another particularly advantageous embodiment of the invention, the valve body is at least in that local area concave and arched. This ensures particularly favorable flow guidance of the gaseous fuel, so that the gaseous fuel can be well delivered into the combustion chamber.

[0024] Another embodiment is characterized in that the narrowed local area of ​​the valve body ends at a wall formed, particularly on the end side of the valve body facing the combustion chamber, which extends in a plane perpendicular to the direction of movement. This allows the gaseous fuel to be guided particularly purposefully and precisely, thus enabling it to be advantageously delivered into the combustion chamber.

[0025] In other particularly advantageous designs of the invention, the valve body is at least partially, and especially at least primarily or completely, hollow. This allows the valve to remain sufficiently light, enabling it to move dynamically, i.e., very quickly, between the closed and open positions. This allows the gaseous fuel to be efficiently delivered into the combustion chamber.

[0026] Ultimately, it proved particularly advantageous that the valve seat was circular. This ensured that the gaseous fuel was guided in a flow particularly well along its path through the housing.

[0027] It is also particularly advantageous that the injector has an electrically operated actuator, i.e., an electro-actuator, whereby the valve can be moved from at least one position to the other using electrical energy or current. In other words, the actuator is supplied with electrical energy or current in order to move the valve from one position to the other by means of the actuator. Thus, gaseous fuel can be delivered into the combustion chamber, particularly as needed. Preferably, one position is the closed position, and therefore the other position is preferably the open position.

[0028] A second aspect of the invention relates to an internal combustion engine designed as a gas engine, having at least one injector according to a first aspect of the invention. The advantages and advantageous designs of the first aspect of the invention should be regarded as advantages and advantageous designs of the second aspect of the invention, and vice versa. Attached Figure Description

[0029] Other advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and in conjunction with the accompanying drawings. The features and combinations of features mentioned above in the specification, as well as those mentioned below in the description of the drawings and / or individually shown in the drawings, may be used not only in their respective specified combinations, but also in other combinations or individually, without departing from the scope of the invention. In the drawings:

[0030] Figure 1 A partial schematic cross-sectional view of an internal combustion engine designed as a gas engine, having an injector of the present invention according to a first embodiment;

[0031] Figure 2 A partial schematic cross-sectional view of the injector according to the second embodiment is shown;

[0032] Figure 3 A partial schematic cross-sectional view of the injector according to the third embodiment is shown;

[0033] Figure 4 A partial schematic cross-sectional view of the injector according to the fourth embodiment is shown.

[0034] In the figure, identical or functionally identical parts are labeled with the same reference numerals. Detailed Implementation

[0035] Figure 1A portion of an internal combustion engine 10, designed as a gas-fired engine, is shown in schematic cross-section. This internal combustion engine 10 is a component of a motor vehicle. This means that a motor vehicle, preferably designed as an automobile, especially a passenger car or commercial vehicle, has this internal combustion engine in its fully manufactured state and can be driven by means of the internal combustion engine 10. The internal combustion engine 10 includes a cylinder block 12, preferably designed as a cylinder crankshaft housing, having at least one cylinder 14, i.e., forming or defining at least one cylinder. For this purpose, the cylinder block 12 has a cylinder wall 16 serving as a first combustion chamber wall, wherein the cylinder 14 is directly defined and thus constituted by the cylinder wall 16. The internal combustion engine 10 includes a housing member 17, separately formed from the cylinder block 12, which is designed, for example, as a cylinder head. The housing member 17 is connected to the cylinder block 12. The housing member 17 includes or forms a combustion chamber top 18, which is associated with the cylinder 14. The internal combustion engine 10 also includes a piston 20, which is movably housed within the cylinder 14. Piston 20, cylinder 14, and combustion chamber top 18 each partially define the combustion chamber 22 of the internal combustion engine 10, wherein piston 20, especially its... Figure 1 The piston recess, not shown, has or forms a second combustion chamber wall that partially defines the combustion chamber.

[0036] During the ignition operation of the internal combustion engine 10, the combustion process takes place in the combustion chamber 22. This combustion process, also simply referred to as the combustion of the fuel-air mixture, involves the gaseous fuel that is fed into the combustion chamber 22. The internal combustion engine 10 operates in its ignition-operated mode using this gaseous fuel. Figure 1 In the illustrated embodiment, gaseous fuel is directly injected into combustion chamber 22 during each working cycle of the internal combustion engine, thereby being delivered into combustion chamber 22. Furthermore, the mixture includes air, also referred to as fresh air, which is introduced into combustion chamber 22. A spark plug is preferably used to ignite the mixture. It is also preferred that the internal combustion engine operates according to the principle of an externally ignited engine, i.e., by means of one or more externally ignited combustion methods.

[0037] Furthermore, the internal combustion engine 10 includes an injector 24 associated with the combustion chamber 22, through which gaseous fuel can be directly injected and thus delivered into the combustion chamber 22. This means that in each working cycle of the internal combustion engine 10, gaseous fuel is directly injected into the combustion chamber 22 by means of the injector 24, especially in the case of forming at least one or exactly one fuel jet, also known as a jet stream, consisting of gaseous fuel generally flowing out of the injector 24 and thus into the combustion chamber 22.

[0038] exist Figure 1 In the illustrated embodiment, the internal combustion engine 10 is a hydrogen engine, and the gaseous fuel is hydrogen. Here, the injector 24 has a housing 26 through which the gaseous fuel (hydrogen) can flow. Figure 1The illustrated embodiment has an outlet 28, also known as an overflow orifice, through which gaseous fuel can flow. Through outlet 28, gaseous fuel can be fed or discharged from housing 26 to deliver gaseous fuel, particularly for direct injection into combustion chamber 22. For example, outlet 28 is designed as an orifice, and therefore is also referred to as an outlet or overflow orifice. It can be seen that gaseous fuel flowing through housing 26 can be delivered from housing 26 and generally from injector 24 via outlet 28 and thus directly injected into combustion chamber 22. Injector 24, and especially housing 26, also has a valve seat 30. Figure 1 In the illustrated embodiment, the valve seat 30 is formed by a housing 26. Specifically, the valve seat 30 is formed by a first housing member 32 of the housing 26. It is conceivable that the housing 26 has a second housing member 34, which is formed separately from and connected to the housing member 32, for example. In particular, the housing members 32 and 34 are connected to each other in such a way that they are fixed together, thus preventing relative movement between the housing members 32 and 34. The housing 26, and especially the housing member 32, has a flow port 36, also known as a through hole, around which the valve seat 30 extends circumferentially in the housing 26 and therefore circumferentially in the flow port 36. Figure 1 In the embodiment shown, the valve seat 30 and the flow port 36 are circular.

[0039] The injector 24 also has a valve 38, which can be used along the... Figure 1 The direction of movement, indicated by the double arrow 40, is relative to the housing 26 and therefore relative to the housing members 32, 34 and the valve seat 30 in the closed position with at least one or exactly one of them. Figure 1 The open position shown represents at least one or only translational movement. The closed position is also referred to as the first position, and the open position is referred to as the second position.

[0040] It can be seen that housing 26 has a first housing region 42 and a second housing region 44, through which gaseous fuel flowing through housing 26 can pass. With respect to the direction of movement and viewed from combustion chamber 22, housing region 42 is located on the other side of valve seat 30 or flow port 36, while housing region 44 is located on this side. In the closed position, valve element 38, especially valve body 46, rests on valve seat 30, thereby blocking flow port 36 by means of valve element 38, especially valve body 46, thus fluidly isolating housing regions 42 and 44 from each other. It can be seen that housing region 44 has an outlet 28. This specifically means that outlet 28 opens into or to the entire periphery of injector 24 and thus into combustion chamber 22 on one side or at one end. On the other side or at the other end, outlet 28 opens into housing 26 and thus into housing region 44. Outlet 28 is thus fluidly separated from housing region 42 by means of valve 38 in the closed position, wherein housing region 44 is arranged downstream of housing region 42 in the flow direction of gaseous fuel flowing through housing 26 and, consequently, housing regions 42, 44. Therefore, in the closed position of valve 38, gaseous fuel cannot flow from housing region 42 into housing region 44 and thus cannot flow through outlet 28, thereby preventing gaseous fuel from flowing out of housing 26, and in particular from the injector 24 in general, in the closed position of valve 38. This prevents gaseous fuel from being injected into, and in particular, into combustion chamber 22 by the injector 24, in the closed position.

[0041] However, in the open position, valve 38 opens the flow port 36, thereby connecting housing regions 42 and 44 via the flow port 36. Gaseous fuel can thus flow through housing regions 42 and 44 and the outlet 28 in the open position of valve 38, allowing the injector 24 to spray or be able to spray gaseous fuel. Thus, the gaseous fuel is directly injected into the combustion chamber 22 via the injector 24. In other words, in the open position of valve 38, the gaseous fuel flowing through housing regions 42 and 44 can be discharged from the housing 26 via the outlet 48 and therefore generally from the injector 24.

[0042] Figure 1 A first embodiment of the injector 24 is shown. In order to facilitate the flow of gaseous fuel, particularly in the open position of the valve 38, and thus advantageously deliver it into the combustion chamber 22, in the first embodiment, the valve 38 is provided to move at least partially into the second housing region 44 as it moves from the closed position to the open position. In other words, in order for the valve 38 to move from the closed position to the open position, the valve 38 extends at least or only translationally relative to the housing 26 and, consequently, relative to the valve seat 30 in a direction parallel to the direction of movement. Figure 1Arrow 48 indicates movement in the opening direction, which is specifically from housing region 42 to housing region 44. Therefore, valve 38 is an outwardly opening valve, but here, valve 38, especially its combustion chamber side end E formed particularly by valve body 46, is located within housing 26 and thus in the second housing region 44 at both locations. Furthermore, in the first embodiment, valve 38 has a valve body portion 50 formed by valve body 46, located in both locations within the second housing region 44, which in the second embodiment is at least, in a localized area, at least primarily and therefore at least more than half or completely raised. In the first embodiment, valve body portion 50 is outwardly arched and thus protrudes into the second housing region 44, wherein valve body portion 50 is designed as a truncated spherical shape.

[0043] In the closed position of valve 38, the second housing region 44 has an internal volume through which gaseous fuel can flow, wherein the valve body portion 50 occupies at least one-third, and particularly at least half, of the internal volume of the second housing region 44 in the closed position. Thus, the loss volume can be kept very small.

[0044] Injector concepts with inwardly or outwardly opening nozzle needle valves are known. However, in both injector concepts, a large closing force is applied by a hydraulic system to minimize leakage. Electrically controlled or electrically operated injectors cannot achieve such a large closing force, therefore the valve seat 30 should be particularly protected against roughness and thermal deformation. This is possible when the valve seat 30 is housed within the housing 26. The housing region 44 is at least partially, especially at least primarily and therefore more than half, more preferably entirely, defined or constituted, by the hood region 52 of the housing 26, also known as the hood. For example, the hood region 52 is constituted or defined by a housing member 34 that can be designed as a single unit. The hood, and therefore the hood region 52, is used for jet shaping, and thus for forming the aforementioned fuel jet (ejection stream). For this purpose, the hood has exactly one outlet 28, which can shape the gaseous fuel or fuel jet composed of gaseous fuel flowing through the outlet 28. It is conceivable that the injector 24, especially the hood, has multiple outlets 28, for example designed as orifices. Because the valve body 50 is located in both positions within the housing region 44, the valve body 50 or valve element 38 retracts relative to the outlet 28 and therefore toward the housing 26. This avoids excessive load on the valve seat 30, especially thermal load.

[0045] The injector 24 is preferably an electrically controlled electric injector. This means that it is preferably equipped with an electric actuator, which can move the valve 38 from at least one position to another using electrical energy or current.

[0046] Typically, the structure dictates a relatively large hood space, which refers to the aforementioned internal volume of the shell region 44. The hood space is a volume that, apart from or defined by the actual combustion chamber 22, except for one or more outlets 28. Typically, especially when the outlets 28 are designed to be large, there is a possibility that flames could arguably “escape” from the combustion chamber 22 into the hood space (shell region 44). Furthermore, since the hood walls are exposed within the combustion chamber 22, the temperature within the hood space may be higher relative to the combustion chamber 22. This creates a risk of self-ignition within the hood space. During gaseous fuel injection, a large velocity gradient occurs in the hood space, which may partially create parasitic vortex structures.

[0047] To avoid the aforementioned disadvantages and problems, in the first embodiment, the valve body portion 50 is configured as a particularly convex arched structure. The valve body portion 50 thus functions as a jet-forming cap, thereby advantageously guiding gaseous fuel in a flow-facilitating manner. In the open position, gaseous fuel flows through housing regions 42, 44, whereby the gaseous fuel flows toward and around the valve body portion 50. In this case, the valve body portion 50 can be designed accordingly to particularly facilitate the flow of gaseous fuel. The valve element 38 is therefore not designed as a simple lift valve with a simple valve disc as the valve body 46; instead, the valve body 46 or its valve body portion 50 in the first embodiment is designed as a truncated spherical shape and thus a raised structure. Compared to conventional solutions, the valve body 46 or valve body portion 50 is therefore a jet-forming cap with optimized flow shape, which significantly reduces the idle volume within the cap space and causes the gaseous fuel to flow advantageously and directionally through the remaining cap space. Due to the significantly increased surface-to-volume ratio of the valve body 50 compared to conventional solutions, hot spots, known as hotspots, within the hood space are avoided, thereby reducing the risk of spontaneous combustion within the hood space compared to conventional solutions. Compared to conventional solutions, the valve member 38 extends below the conventionally positioned valve disc in a flow-optimized manner into the hood and subsequently the housing region 44, thereby confining the flow of gaseous fuel or its contents within the hood and thus reducing, in particular, the idle hood volume. The idle hood volume specifically refers to the volume within which the valve member 38 is not positioned in the open position.

[0048] Directional flow through the air cap space also allows for the design of the jet direction in the combustion chamber 22, particularly regarding the constancy of the jet direction. When using multiple outlets, the interaction between the outlets caused by vortices is reduced or avoided, thereby obtaining a more uniform jet pattern.

[0049] To maintain a sufficiently small weight for the valve element 38, also known as the injection valve, and thus ensure sufficiently high valve element 38 dynamics, the valve body 50 or valve body 46 may be designed to be hollow. Therefore, in the first embodiment, the valve body 46 has a cavity 54 within it. The valve element 38 includes the valve body 46 and the rod 56. The rod 56 and the valve body 46 can be integrally formed. It may be particularly advantageous when the valve body 46 is designed to be hollow, that the rod 56 and the valve body 46 are designed as independently constructed yet interconnected components. For example, the valve body 46 and consequently the valve body 50 may be connected to the rod 56 or to the injection valve blank by welding, especially laser welding.

[0050] Figure 2 A second embodiment of the injector 24 is shown. In the second embodiment, the valve body portion 50 is convex and protrudes from the housing region 44, wherein the valve body portion 50 may also be designed as a truncated spherical shape.

[0051] Figure 3 A third embodiment of the injector 24 is shown. In this third embodiment, the valve body 50 is designed in a conical or truncated cone shape, meaning that the valve body 50 narrows continuously or intermittently in the direction away from the valve seat 30 and therefore in the opening direction indicated by arrow 48. Here, a local region T of the valve body 50 narrows in the opening direction, wherein the local region T of the valve body 50 that narrows in the opening direction ends at the wall 58 of the valve body 50, which extends in a plane perpendicular to the direction of movement. The wall 58 is flat when viewed outward or in the opening direction. In all three embodiments, it is also specified that the valve body 50 is designed to be rotationally symmetrical about a longitudinal central axis L that extends parallel to or coincides with the direction of movement. This is particularly advantageous for the fluid guidance of gaseous fuel.

[0052] Figure 4 The injector 24 according to the fourth embodiment is shown in a schematic cross-sectional view. The injector 24 here has a plurality of, for example, at least or exactly 10 or other numbers of outlets 28. This means that the following and previous embodiments are applicable and advantageous not only to wind caps having exactly one outlet 28, also called an overflow, but also to wind caps having multiple overflows. Optimization of the dead space within the wind cap space can be achieved here.

[0053] List of reference numerals

[0054] 10 Internal Combustion Engine

[0055] 12-cylinder block

[0056] 14 cylinders

[0057] 16 Cylinder wall

[0058] 17 Housing components

[0059] 18. Combustion chamber top wall

[0060] 20 Pistons

[0061] 22 Combustion Chamber

[0062] 24 Injectors

[0063] 26. Shell

[0064] 28 Outlet

[0065] 30 Valve seat

[0066] 32 Housing components

[0067] 34 Housing components

[0068] 36 distribution outlets

[0069] 38 valve components

[0070] 40 Double Arrows

[0071] 42 First shell region

[0072] 44 Second shell region

[0073] 46 Valve body

[0074] 48 arrows

[0075] 50 Valve body section

[0076] 52 Hood Area

[0077] 54 Cavity

[0078] 56 strokes

[0079] 58 wall

[0080] E end

[0081] L longitudinal center axis

[0082] T local region

Claims

1. An injector (24) for delivering gaseous fuel into a combustion chamber (22) of an internal combustion engine (10), the injector having a housing (26) through which gaseous fuel can flow, the housing having at least one outlet (28) through which gaseous fuel can be delivered from the housing (26) via the outlet to deliver gaseous fuel into the combustion chamber (22), the injector further having a valve seat (30) and a valve member (38), the valve member being at least translationally movable in a direction of motion (40) relative to the housing (26) and relative to the valve seat (30) between the following positions: - In the closed position, the valve (38) rests on the valve seat (30) and thereby separates the first housing region (42) of the housing (26) through which gaseous fuel can flow from the second housing region (44) of the housing (26) through which gaseous fuel can flow, located downstream of the first housing region (42) in the flow direction of gaseous fuel flowing through the housing (26) and having the outlet (28) from each other, thereby preventing gaseous fuel from flowing out of the housing (26) via the outlet (28); and - As at least one open position of the second position, in which the valve member (38) and the valve seat (30) are spaced apart from each other, such that the housing regions (42, 44) are in circulation connected and gaseous fuel flowing through the housing regions (42, 44) can be discharged from the housing (26) via the outlet (28). Its features are, The valve (38) is at least partially movable into the second housing region (44) when it moves from the closed position to the open position and has a valve body portion (50) disposed in the second housing region (44) in both positions, the valve body portion being raised in at least a local area (T) of the valve body portion (50) and / or narrowed in a direction away from the valve seat (30), the second housing region (44) being at least partially defined by a vent region (52) of the housing (26) having one or more of the said outlets (28).

2. The injector (24) according to claim 1, characterized in that, In the closed position of the valve (38), the second housing region (44) has an internal volume through which gaseous fuel can flow, wherein the valve body (50) occupies at least one-third of the internal volume of the second housing region (44) in the closed position.

3. The injector (24) according to claim 1 or 2, characterized in that, The valve body (50) is configured to be rotationally symmetrical about the central axis (L) extending parallel to the direction of motion (40) of the valve body (50).

4. The injector (24) according to claim 1 or 2, characterized in that, The valve body portion (50) is at least primarily convex in the local region (T) and thus protrudes into the second housing region (44).

5. The injector (24) according to claim 1 or 2, characterized in that, The valve body (50) is at least primarily shaped as a truncated sphere in the local region (T).

6. The injector (24) according to claim 1 or 2, characterized in that, The valve body (50) is concave and arched at least in the local area (T).

7. The injector (24) according to claim 1 or 2, characterized in that, The narrowed local area (T) of the valve body (50) ends at the wall (56) of the valve body (50), which extends in a plane perpendicular to the direction of movement (40).

8. The injector (24) according to claim 1 or 2, characterized in that, The valve body (50) is at least partially hollow.

9. The injector (24) according to claim 8, characterized in that, The valve body (50) is mainly or completely hollow.

10. The injector (24) according to claim 1 or 2, characterized in that, The valve seat (30) is circular.

11. A gas engine (10) having at least one injector (24) according to any one of claims 1 to 10.

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