Injection valve

Abstract

For an injection valve which can be simply produced, permits a high mass throughflow rate, ensures a high degree of tightness and has low wear, it is provided that an end face (20) facing the valve plate (3) is provided on the valve seat (2) and the at least one throughflow opening (10) leads into the end face (20), wherein the orifice (24) of the at least one throughflow opening (10) in the end face (20) is in the form of an open curve, that a sealing elevation (23) is provided on the end face (20), the sealing elevation protruding from the end face (20) in the axial direction towards the gas volume (7) and the sealing elevation (23) completely surrounding the at least one throughflow opening (10), and that at least one stop (25) is provided on the valve seat (2), the stop protruding from the end face (20) of the valve seat (2) in the axial direction by a stop height (HA) towards the gas volume (7), wherein an axial end of the sealing elevation (23) facing the gas volume (7) protrudes by a predetermined differential distance (D) of between 0.02 mm and 0.5 mm further into the gas volume (7) than an axial end of the stop (25) facing the gas volume (7) such that, when the injection valve (1) is closed, the valve plate (3) does not bear against the stop (25) because of the differential distance (D).

Description

[0001] injection valve

[0002] The present invention relates to an injection valve having a valve seat and a valve plate cooperating with the valve seat to open and close the injection valve, wherein the valve plate is connected to a magnet armature and the magnet armature cooperating with an electromagnet in the injection valve to lift the valve plate from the valve seat to open the injection valve, wherein a gas volume is provided in the injection valve which is connected to an inlet opening of the injection valve and a valve body of the valve seat at least partially delimits the gas volume in the injection valve and at least one through-flow opening is provided in the valve body of the valve seat which, when the valve plate is lifted from the valve seat, connects the gas volume to an outlet opening of the injection valve and the valve plate closes the at least one through-flow opening when the valve plate rests against the valve seat,wherein an end face facing the valve plate is provided on the valve seat and the at least one through-flow opening opens into the end face, wherein the mouth of the at least one through-flow opening is formed in the end face in the form of an open curve, and a sealing elevation is provided on the end face, which projects from the end face in the axial direction in the direction of the gas volume and the sealing elevation completely surrounds the at least one through-flow opening.

[0003] In gas engines with gaseous fuel, such as natural gas (compressed natural gas, CNG) or hydrogen, port fuel injection is often used using a port fuel valve. The gaseous fuel is injected at existing pressure into the intake manifold leading to the cylinder of the combustion engine or into the intake tract via the injection valve. The injection valve is supplied with fuel at a predetermined pressure by a fuel distribution system (fuel rail). The advantage of port fuel injection over direct injection into the cylinder is the lower injection pressure of the gaseous fuel, typically 0 to 30 bar differential pressure to the ambient air, which allows for simpler design of the fuel supply components.Further advantages of port fuel injection over direct injection are the larger available injection window and the longer mixing paths and mixing timescales, which enable better homogenization of the mixture in the cylinder. The injection, and in particular the amount of gaseous fuel, is controlled by a control unit, particularly via the opening time of the injection valve. This allows the amount to be precisely metered. The main requirements for an injection valve are a high flow rate to enable the required gas quantities to be delivered within the short possible opening times (injection window). Equally important is the wear resistance of the injection valve due to the very high switching frequency and switching rate. This presents a significant challenge, particularly with oil-free gaseous fuels such as hydrogen, which do not provide lubrication for the valve components.It is equally important that the injection valve leakage is as low as possible in order to prevent, at least as far as possible, the escape of gaseous fuel when the injection valve is closed.

[0004] Such injection valves are known from the prior art. WO 2022 / 180593 A1 shows an electromagnetically actuated injection valve. In this injection valve, a valve plate is arranged on a solenoid armature, which interacts with a valve seat. When the electromagnet is activated, the solenoid armature is attracted to the valve plate, and the valve plate lifts off the valve seat. When the solenoid armature is deactivated, the solenoid armature and valve plate are pressed against the valve seat by a spiral spring, and the injection valve is closed. The solenoid armature and valve plate are guided in the injection valve via a clamped spring plate. To achieve a high mass flow through the injection valve, two concentric, annular, radially spaced-apart sealing projections are provided on the valve seat, which interact with the valve plate. Flow openings for the gaseous fuel are provided between the concentric sealing projections and distributed around the circumference.A central, non-through recess is provided radially inward, which is connected to the circumferential surface of the valve seat via radial bores. The radial bores are provided between the flow openings. The valve seat is arranged in the injection valve in a gas volume that is connected to the fuel supply. The central recess is also connected to this gas volume via the radial bores. This allows the fuel to flow to the flow openings from both the radial outside and the radial inside when the injection valve is open, i.e. when the valve plate is lifted away from the valve seat, specifically from the sealing projections, thereby increasing the potential mass flow. However, the radial bores in the valve seat make the manufacture of the valve seat more complex because several manufacturing steps are required.

[0005] CN 113202658 B also shows an injection valve with two concentric, annular, radially spaced sealing lobes on the valve seat that interact with a valve plate. The fuel is supplied to the central area of ​​the valve seat and the radially outer area of ​​the valve seat via holes in the valve plate. This makes the valve plate more complex to construct and also weakens its strength, which means it must be built larger. The valve plate is made of plastic in the area of ​​the sealing lobes. It also describes an annular stop for the valve plate located radially on the outside of the valve seat, which is slightly lower than the sealing lobes. The stop prevents the valve plate from pressing too deeply onto the sealing lobes due to the spring force and the plastic material, which would impair the opening behavior of the injection valve.This means that the valve plate also rests against the stop when closed. However, this reduces the contact pressure between the valve plate and the sealing lobes, which in turn can impair the valve's tightness.

[0006] CN 113187901 A and US 2014 / 0231693 A1 also each show an injection valve with concentric, annular, radially spaced sealing protrusions on the valve seat that interact with a valve plate. These injection valves also feature a stop for the valve plate, with the valve plate resting against the stop when closed. However, this reduces the contact pressure between the valve plate and the sealing protrusions, which in turn can impair the valve's tightness.

[0007] US 2015 / 0014448 A1 shows an injection valve with radially aligned flow openings surrounded by sealing ridges. When closed, the valve plate rests against the sealing ridges. Due to the high closing speed of the valve plate when the injection valve is closed, high contact forces arise between the sealing ridges and the valve plate due to the impact of the valve plate on the sealing ridges. This places very high stress on the valve plate and sealing ridges, resulting in significant wear.

[0008] It is an object of the present invention to provide an injection valve with a valve seat and a valve plate which is simple to manufacture, which enables a high flow rate through the injection valve, which ensures high tightness and which has low wear.

[0009] This is achieved by providing at least one stop on the valve seat which protrudes from the end face of the valve seat in the axial direction by a stop height in the direction of the gas volume, wherein an axial end of the sealing projection facing the gas volume protrudes further into the gas volume by a predetermined differential distance of between 0.02 mm and 0.5 mm than an axial end of the stop facing the gas volume, so that the valve plate does not rest on the stop when the injection valve is closed due to the differential distance. A valve seat designed in this way is simple and can therefore be easily manufactured. Because the sealing projection protrudes from the end face, the flow opening can be approached from all sides, which increases the flow mass flow. The sealing projection reduces the contact area between the valve seat and valve plate, which increases the contact pressure and thus the tightness.By extending the axial end of the sealing lobe further into the gas volume by a differential distance than the axial end of the stop, the stop at least partially absorbs the forces generated when the valve plate impacts the valve seat, thus preventing overloading of the valve seat, particularly the sealing lobes, or the valve plate. When the injection valve is closed, the differential distance ensures that the valve plate rests axially only, or at least largely only, on the sealing lobes, thus increasing the sealing effect.

[0010] To ensure the most unhindered inflow of gaseous medium to the through-flow opening, the at least one stop is advantageously arranged at a distance from the density elevation of the at least one through-flow opening.

[0011] To increase the mass flow through the injection valve, several flow openings can open into the end face, distributed over the circumference of the valve seat, wherein each opening in the end face is designed in the form of an open curve, and a sealing projection is provided on the end face for each opening, which projects from the end face in the axial direction in the direction of the gas volume, and each sealing projection completely surrounds the opening of one of the several flow openings. To ensure the most unhindered inflow of gaseous medium to the flow opening, it is advantageous if the sealing projections are arranged spaced apart from one another in the circumferential direction, so that an inflow channel is formed between two sealing projections spaced apart in the circumferential direction.The distribution of gaseous medium for inflow to the flow opening can be further improved if a central free area is provided on the valve seat, which is connected to the inflow channel.

[0012] Likewise, for the most unhindered inflow of gaseous medium to the flow opening, it is advantageous if, in the case of several stops, each stop is arranged at a distance from the sealing elevations.

[0013] The inflow of gaseous medium to the flow opening can be further improved if a projection projecting in the direction of the gas volume is arranged on the end face in the region of an opening of at least one flow opening, preferably all flow openings, so that the opening of the at least one flow opening and the sealing elevation completely surrounding the at least one flow opening are provided at an axial end of the projection facing the gas volume. In the case of multiple projections, it is advantageous if the projections are arranged at a distance from one another to ensure the most unhindered inflow of gaseous medium to the flow opening.

[0014] The flow volume can be advantageously increased if the orifice of a flow opening has a radial leg connected to a circumferentially extending section of the orifice. This allows the available frontal area to be effectively utilized to achieve a high mass flow. This can be further improved if the orifice has two radial legs, each connected to a circumferentially extending section of the orifice.

[0015] If at least one sealing protrusion is rounded in the direction of the gas volume, the valve plate can be prevented from striking a sharp edge, thereby reducing wear on the sealing protrusion and / or the valve plate. Likewise, it is advantageous if at least one edge facing the gas volume, preferably all edges of at least one stop, preferably all stops, are rounded in the direction of the gas volume.

[0016] The present invention will be explained in more detail below with reference to Figures 1 to 6, which show exemplary, schematic and non-limiting advantageous embodiments of the invention.

[0017] Fig.1 an injection valve according to the invention,

[0018] Fig.2 possible designs of the mouth of a flow opening,

[0019] Fig.3 and 4 sections through a flow opening,

[0020] Fig.5 shows a preferred embodiment of a valve seat according to the invention and

[0021] Fig.6 a section through the valve seat.

[0022] An injection valve 1 according to the invention has a valve seat 2 and a valve plate 3 which interacts with the valve seat 2 to open and close the injection valve 1. The valve plate 3 can be moved back and forth in the injection valve 1 between a closed position in which the valve plate 3 rests against the valve seat 2 in the axial direction (shown in Fig. 1), and an open position in which the valve plate 3 is lifted away from the valve seat 2 in the axial direction. The axial direction is thus in the direction of movement of the valve plate 3. In order to move the valve plate 3, it is connected to a magnet armature 4, so that the valve plate 3 and the magnet armature 4 form an armature assembly 6. The valve plate 3 and magnet armature 4 are moved together with the armature assembly 6. During operation of the injection valve 1, the magnet armature 4 interacts with an electromagnet 5 in the injection valve 1 to move the armature assembly 6 axially by energizing the electromagnet 5.An electrical connection required for the operation of the electromagnet 5 is not shown in Fig.1 and is also not relevant to the invention.

[0023] The armature assembly 6 can optionally (as shown in Fig. 1) also have a spring plate 12, via which the armature assembly 6 is guided radially in the injection valve 1. The spring plate 12 is arranged, for example, between the valve plate 3 and the magnet armature 4. The spring plate 12 can also cause the valve plate 3 to return to the closed position when the electromagnet 5 is not energized. In the exemplary embodiment shown, the spring plate 12 is clamped on the radially outer circumference, here in the housing 11 of the injection valve 1. However, another return element, for example a spiral spring between the magnet armature 4 and the electromagnet, can also be provided for returning to and holding the closed position.

[0024] A gas volume 7 is provided in the injection valve 1 and is connected to an inlet opening 8 of the injection valve 1. During operation of the injection valve 1, a gaseous medium is fed into the gas volume 7 via the inlet opening 8. The gas volume 7 is at least partially delimited by the valve seat 2, in the exemplary embodiment shown in Fig. 1, in the axial direction. The gas volume 7 in the injection valve 1 is otherwise essentially delimited by the housing 11 of the injection valve 1 and by the electromagnet 5, and / or by other components of the injection valve 1. At least one through-flow opening 10 is provided in the valve seat 2, which, when the valve plate 3 is lifted off the valve seat 2, connects the gas volume 7 to an outflow opening 9 of the injection valve 1. Typically, a plurality of through-flow openings 10 are provided on the valve seat 2, distributed over the circumference.The valve plate 3 closes the at least one flow opening 10, or the plurality of flow openings 10, when the valve plate 3 rests against the valve seat 2. When the injection valve 1 is open, i.e., when the valve plate 3 is lifted from the valve seat 2, a flow channel is created from the inlet opening 8, through the gas volume 7 and the at least one flow opening 10, to the outlet opening 9 of the injection valve 1. When the injection valve 1 is closed, this flow channel is interrupted. When the injection valve 1 is used, the outlet opening 9 opens, for example, into an intake manifold or an intake tract of an internal combustion engine.

[0025] The individual parts and components of the injection valve 1 are arranged in a housing 11. The housing 11 is preferably designed in several parts for manufacturing and assembly reasons.

[0026] By controlling the opening time of the injection valve 1 by means of the electromagnet 5 and the predetermined known gas pressure of the supplied gaseous medium, the quantity of the gaseous medium discharged via the outlet opening 9 can be precisely controlled.

[0027] The invention relates to the design of the valve seat 2 of the injection valve 1, which is shown in Figures 2 to 4 by way of example and in various designs. The valve seat 2 according to the invention has a valve body 21 with an end face 20 facing the valve plate 3. The valve body 21 forms the boundary of the gas volume 7 in the injection valve 1. The end face 20 does not necessarily have to be a flat surface and does not have to be a continuous surface, but could also be formed by several, even non-connected, partial surfaces. The at least one flow opening 10, or the several flow openings 10, of the valve seat 2 opens into the end face 20, so that an opening 24 of the flow opening 10 is formed on the end face 20. The at least one flow opening 10 forms a channel for the gaseous medium that passes through the valve body 21.The continuous channel connects, for example, the end face 20 with an opposite end face 22 (see Fig.3) of the valve body 21, or also with a circumferential surface 27 of the valve body 21.

[0028] The orifice 24 of the at least one flow opening 10 has the shape of an open curve in the end face 20. Thus, the end face 20 has a beginning and an end of the orifice 24 of the flow opening 10, which do not coincide.

[0029] Typically, several flow openings 10, each with an orifice 24, are provided in the end face 20, wherein the orifices 24 are distributed over the circumference of the end face 20 and arranged spaced apart from one another in the circumferential direction. Typically, one to eight flow openings 10, each with an orifice

[0030] 24 is provided.

[0031] At least one density elevation 23 is provided on the end face 20, which protrudes from the end face 20 in the axial direction towards the gas volume 7. The density elevation 23 completely surrounds the mouth 24 of the at least one flow-through opening 10. The density elevation 23 therefore surrounds the mouth 24 on all sides, i.e. both in the radial direction and in the circumferential direction. The density elevation 23 can completely surround the at least one flow-through opening 10 because the mouth 24 of the flow-through opening 10 is an open curve. The mouth 24 of the at least one flow-through opening 10 in the form of an open curve in the end face 20 has the effect that the density elevation 23 forms a closed curve in the end face 20.

[0032] Furthermore, at least one stop 25 is provided on the end face 20 of the valve seat, which protrudes from the end face 20 in the direction of the gas volume by a stop height HA. The stop 25 is preferably spaced from the sealing elevation 23, i.e., both circumferentially and radially.

[0033] Because the density elevation 23 and also the stop 25 rise from the front surface 20, the gaseous medium M can flow from all sides to the density elevation 23 and, when the valve plate 3 is lifted, flow from all sides into the flow opening 10. This allows the achievable mass flow through the flow opening 10 for a specific opening time of the injection valve 1 to be increased. After the stop

[0034] 25 is preferably spaced apart from the sealing elevation 23, the stop 25 does not disturb the inflow of gaseous medium to the flow opening 10, or at least only slightly.

[0035] A stiffening web 33 can also be provided between a sealing elevation 23 and a stop 25 spaced therefrom, as shown in Fig. 5. Such a stiffening web 33 serves only to stiffen the sealing elevation 23 projecting axially from the end face 20 and the stop 25 projecting axially from the end face 20. In any case, the stiffening web 33 does not form a stop 25, but is axially deeper (seen from the end face 20) than the stop 25. The valve plate 3 therefore does not come into axial contact with the axial end of the stiffening web 33 facing away from the end face 20. Thus, the stiffening web 33 does not disrupt the inflow of gaseous medium to the flow opening 10.

[0036] A valve seat 2 can be provided with several flow openings 10 with associated orifices 24 in the end face 20, wherein the flow openings 10 are arranged in the end face 20 distributed over the circumference. The orifices 24 of the several flow openings 10 are preferably designed identically (geometry, position, orientation, etc.) because this facilitates manufacturing. However, flow openings 10 with differently designed orifices 24 can also be provided. In the case of several flow openings 10, each orifice 24 of each flow opening 10 is completely surrounded by a sealing elevation 23.

[0037] The sealing protrusions 23 are arranged at a distance from one another in the circumferential direction, and optionally also in the radial direction, in order to disrupt the inflow of the gaseous medium to the respective through-flow openings 10 as little as possible. An inflow channel 28 is thus formed in the circumferential direction between two adjacent sealing protrusions 23. Preferably, a central free region 29 is formed between the plurality of sealing protrusions 23 in the end of the valve seat 2 facing the gas volume 7, i.e. in the region of the end face 20. The central free region 29 is connected via an inflow channel 28 to the outer circumference of the valve seat 2 and thus also to the gas volume 7 in the injection valve 1. This ensures good distribution of the gaseous medium around the sealing protrusions 23 and improves the all-round inflow of the gaseous medium to the through-flow openings 10 when the valve plate 3 is lifted.The central free area 29 can also or additionally be formed as a recess in the valve seat 2.

[0038] Fig. 2 shows various exemplary embodiments of the orifice 24 of the at least one flow opening 10. In addition, a multitude of other embodiments (in terms of geometry, position, orientation, etc.) of the orifices 24 are of course also conceivable. In the embodiment top right, the orifice 24 is designed as a circular arc section and is completely surrounded by the dense elevation 23. However, the orifice 24 could also be designed as a straight line, for example as a chord section. A stop 25 is also shown in this area, which protrudes from the end face 20. The stop 25 is arranged radially inward of the dense elevation 23 and is spaced from the dense elevation 23. The stop 25 could also be arranged spaced from the dense elevation 23 in the circumferential direction.

[0039] Fig. 3 shows a section AA through the mouth 24 and the stop 25 at the top right of Fig. 2. It can be seen that the stop 25 rises from the end face 20 by the stop height HA. Likewise, it can be seen that the density elevation 23 rises from the end face 20 by a density elevation height HD. The stop height HA of the stop 25 and the density elevation height HD of the density elevation 23 are designed such that the axial ends of the density elevation 23 facing the gas volume 7 extend further into the gas volume 7 by a differential distance D than the axial ends of the stop 25 facing the gas volume 7. Preferably, if there are several stops 25, each stop 25 is designed such that the axial ends of the density elevation(s) 23 facing the gas volume 7 extend further into the gas volume 7 by a differential distance D than the axial ends of the stops 25 facing the gas volume 7.

[0040] In Fig. 2, top left, the opening 24 of the at least one flow opening 10, which in turn is completely surrounded by a sealing elevation 23, is radially further inward than in the embodiment top right. The at least one stop 25 can therefore also be arranged radially further outward than the opening 24. The stop 25 is radially spaced from the sealing elevation 23. The stop 25 could also, additionally, be radially further inward than the opening 24, as indicated by the dashed line, or could also be arranged circumferentially spaced from the sealing elevation 23.

[0041] In order to increase the length of the orifice 24 in the end face 20 and to enable more mass flow through the flow opening 10, the orifice 24 in the end face 20 can extend both radially and circumferentially. Such a design is shown in Fig. 2, bottom left. In the design shown, the orifice has two radial legs 24a, 24b, which are connected to one another in the circumferential direction by a section 24c. However, it would also be conceivable to provide an orifice 24 with only one radial leg 24a, 24b, which is connected to a section 24c in the circumferential direction. The orifice is again completely surrounded by a sealing elevation 23.

[0042] The orifice 24 of the flow opening 10 can also be multi-part within the sealing elevation 23 completely surrounding the orifice 24, as shown in the bottom right of Fig. 2. The sealing elevation 23 thus also delimits such a multi-part orifice 24 on all sides, i.e., in the circumferential and radial directions.

[0043] In Fig.2 bottom right it is further shown that the mouth 24 of the at least one flow opening 10, which is completely surrounded by the density elevation 23, can also be aligned radially.

[0044] A radially aligned mouth 24 and also the mouths in Fig.2 top right, top left and bottom left could be designed in several parts, just like the mouth in Fig.2 bottom right.

[0045] In an advantageous embodiment, a projection 26 protruding in the direction of the gas volume 7 is arranged on the end face 20 in the region of an opening 24 of the at least one flow opening 10. The opening 24 is thus arranged in the end face 20 of the projection 26. The end face 20 thus has a step in the axial direction formed by the projection 26. This is illustrated in Fig. 4, which shows a section through the design of the opening 24 in Fig. 2, top left. Due to the projection 26, the stop height HA is also greater in order to achieve the same differential distance D. The advantage of such a projection 26 for the opening 24 of the at least one flow opening 10 is that the free volume for the gaseous medium increases around the sealing elevation 23 when the injection valve is closed. This improves the inflow of the gaseous medium M when the injection valve 1 is open.

[0046] Preferably, a projection 26 is provided for each orifice 24 of a flow opening 10. The projections 26 are advantageously spaced apart from one another both circumferentially and radially in order to form inflow channels 28 between the projections 26 for the inflow of gaseous medium (see, for example, Fig. 5).

[0047] The sectional views in Figs. 3 and 4 show that the edges of the sealing protrusions 23 facing the valve plate 3 are rounded in an advantageous embodiment. This prevents contact between the valve plate 3 and a sharp edge. Such a sharp edge could press into the valve plate 3 in the event of a possible deformation of the valve plate 3 upon closing of the injection valve 1 and damage the valve plate 3. The edge of the stops 25 could also be rounded in the same way.

[0048] Figures 5 and 6 describe an advantageous embodiment of a valve seat 2 according to the invention, with Figure 6 showing an enlarged section CC. In this embodiment, the valve seat 2 has three flow openings 10, which are distributed over the circumference and spaced apart from one another. For each flow opening 10, a projection 26 is provided, which forms the end face 20 for each flow opening 10 (which could again be designed in several parts). The openings 24 of the flow openings 10 each have two radially aligned legs 24a, 24b, which are each connected by a section 24c extending in the circumferential direction. The sections 24c extending in the circumferential direction are each arranged radially inward, so that the legs 24a, 24b protrude from them from the radial inside in a radially outward direction. The openings 24 are thus V-shaped.Between the radial legs 24a, 24b of a flow-through opening 10, a stop 25 is arranged in each case, which is spaced from the projection 26 both in the circumferential direction and in the radial direction. This forms an inflow channel 28 for the gaseous medium both between two adjacent legs 24a, 24b of two adjacent flow-through openings 10, and also between the stop 25 and the projection 26 of a flow-through opening 10. The gaseous medium can also flow into a free, centrally located inner region 29 of the valve seat 2 via the inflow channel 28 between two adjacent legs 24a, 24b. In this way, on the one hand, the available flow area of ​​the flow-through openings 10 can be as large as possible, and at the same time, the inflow of the gaseous medium M to the flow-through openings 10 can be as unhindered as possible when the injection valve 1 is open.

[0049] A further significant advantage of a valve seat 2 according to the invention is that the valve seat 2 can be injection-molded in one piece and requires no post-processing. For this purpose, the valve seat 2 is preferably made of a plastic, preferably a fiber-reinforced plastic, such as a glass-fiber-reinforced or carbon-fiber-reinforced plastic, such as a glass-fiber-reinforced liquid crystal polymer. The valve seat can also be made of PEEK (polyetheretherketone) or PPS (polyphenylene sulfide). Furthermore, the valve plate 3 can also be of a simple design and need not have any openings or bores for supplying the gaseous medium M to the radially inner region of the valve seat 2.

[0050] The valve plate 3 can be made of plastic or metal. In the case of a metal valve plate 3, it is advantageous to provide the end face 31 of the valve plate 3 facing the valve seat 2 with a plastic coating 32, at least in the area of ​​the sealing protrusions 23 on the valve seat 2 (Fig. 1).

[0051] The sealing elevation 23 reduces the contact area between the valve plate 3 and the valve seat 2 and thus increases the contact pressure between the valve plate 3 and the valve seat 2 when the injection valve 1 is closed, which improves the tightness of the closed injection valve 1. When the injection valve 1 is closed, at the moment the valve plate 3 impacts the valve seat 2, stress and force peaks can occur due to the small contact area, which could overload the material of the valve seat 2 and / or the valve plate 3. The stop 25 is provided to prevent the valve plate 3 and the valve seat 2 from interacting with each other over time, which would change the opening behavior of the injection valve 1 or could damage the valve seat 2 or the valve plate 3.This ensures that the valve plate 3 is not pressed too far into the valve seat 2 during the impact moment due to slight deformation of the valve plate 3 and / or the valve seat 2 or, conversely, that the valve seat 2 is not pressed too far into the valve plate 3. For this purpose, the differential distance D between the sealing elevation 23 and the stop 25 is precisely specified. The differential distance D is in the range of 0.02 to 0.5 mm (preferably up to 0.2 mm), which also depends on the size of the injection valve 1. The stop 25 therefore has the additional advantage of at least partially absorbing the impact when the injection valve 1 closes, i.e. when the valve plate 3 impacts the valve seat 2 at high speed during closing. This can reduce the load acting on the valve seat 2 and the valve plate 3 in the area of ​​the sealing elevation 23, thereby reducing wear and extending the service life of the injection valve 1.

[0052] When the injection valve 1 is closed, the valve plate 3 does not rest against the stop 25 due to the differential distance D, which increases the sealing effect due to the higher contact pressure between the valve plate 3 and the valve seat 2. When the injection valve 1 is closed, the valve plate 3 should not rest against the stop 25 in the axial direction, for example because the valve plate 3 presses into the valve seat 2, specifically into the sealing elevations 23, or vice versa. In other words, when the injection valve 1 is closed, the valve plate 3 is spaced apart from the stop 25 in the axial direction. When the injection valve 1 is closed, the valve plate 3 is preferably spaced apart from the stop 25 by at least the differential distance D in the axial direction. If there are multiple stops 25, the valve plate 3 is spaced apart from all stops 25 in the axial direction when the injection valve 1 is closed.

[0053] Fig. 1 shows that the valve seat 2 is advantageously inserted into the housing 11 and axially abuts a projection 30. The valve seat 2 can be pressed and held against the projection 30 by the differential pressure acting between the pressure of the supplied gaseous medium and the pressure acting at the outlet opening 9.

Claims

Patent claims 1 . Injection valve with a valve seat (2) and a valve plate (3) cooperating with the valve seat (2) to open and close the injection valve (1), wherein the valve plate (3) is connected to a magnet armature (4) and the magnet armature (4) cooperating with an electromagnet (5) in the injection valve (1) to lift the valve plate (3) from the valve seat (2) to open the injection valve (1), wherein a gas volume (7) is provided in the injection valve (1), which is connected to an inflow opening (8) of the injection valve (1), and a valve body (21) of the valve seat (2) at least partially delimits the gas volume (7) in the injection valve (1), and at least one through-flow opening (10) is provided in the valve body (21) of the valve seat (2), which through-flow opening (10) connects the gas volume (7) to an outflow opening (9) of the injection valve when the valve plate (3) is lifted from the valve seat (2). (1) and the valve plate (3) closes at least one flow opening (10),when the valve plate (3) rests against the valve seat (2), wherein an end face (20) facing the valve plate (3) is provided on the valve seat (2), and the at least one through-flow opening (10) opens into the end face (20), wherein the opening (24) of the at least one through-flow opening (10) is designed in the end face (20) in the form of an open curve, wherein a sealing elevation (23) is provided on the end face (20), which projects from the end face (20) in the axial direction in the direction of the gas volume (7), and the sealing elevation (23) completely surrounds the at least one through-flow opening (10), characterized in that at least one stop (25) is provided on the valve seat (2), which projects from the end face (20) of the valve seat (2) in the axial direction by a stop height (HA) in the direction of the gas volume (7), wherein an axial end of the sealing elevation (23) facing the gas volume (7) is bent by a specified difference distance (D) between 0.02mm and 0.5mm,preferably between 0.02 mm and 0.2 mm, extends further into the gas volume (7) than an axial end of the stop (25) facing the gas volume (7), so that the valve plate (3) does not rest against the stop (25) in the axial direction due to the differential distance (D) when the injection valve (1) is closed.

2. Injection valve according to claim 1, characterized in that the at least one stop (25) is arranged at a distance from the sealing elevation (23) of the at least one flow opening (10).

3. Injection valve according to claim 1 or 2, characterized in that a plurality of through-flow openings (10) open into the end face (20) distributed over the circumference of the valve seat (2), each opening (24) in the end face (20) being designed in the form of an open curve, that on the end face (20) for each opening (24) a sealing elevation (23) which projects from the end face (20) in the axial direction in the direction of the gas volume (7) and each density elevation (23) completely surrounds the mouth (24) of one of the several flow openings (10).

4. Injection valve according to claim 3, characterized in that the sealing elevations (23) are arranged spaced apart from one another in the circumferential direction, so that an inflow channel (28) is formed between two sealing elevations (23) spaced apart in the circumferential direction.

5. Injection valve according to claim 4, characterized in that a central free area is provided on the valve seat (2) which is connected to the inflow channel (28).

6. Injection valve according to one of claims 1 to 5, characterized in that a plurality of stops (25) are provided on the end face (20), each stop (25) projecting from the end face (20) of the valve seat (2) in the axial direction by a stop height (HA) in the direction of the gas volume (7), an axial end of the sealing elevations (23) facing the gas volume (7) projecting further into the gas volume (7) by a predetermined differential distance (D) between 0.02 mm and 0.5 mm, preferably between 0.02 mm and 0.2 mm, than the axial end of the stops (25) facing the gas volume (7).

7. Injection valve according to claim 6, characterized in that the valve plate (3) does not rest against any stop (25) in the axial direction when the injection valve (1) is closed.

8. Injection valve according to claim 6, characterized in that each stop (25) is arranged at a distance from the sealing elevations (23).

9. Injection valve according to one of claims 1 to 8, characterized in that a projection (26) projecting in the direction of the gas volume (7) is arranged on the end face (20) in the region of an orifice (24) of at least one through-flow opening (10), so that the orifice (24) of the at least one through-flow opening (10) and the sealing elevation (23) completely surrounding the at least one through-flow opening (10) are provided on an axial end of the projection (26) facing the gas volume (7).

10. Injection valve according to one of claims 3 to 8, characterized in that on the end face (20) in the region of the mouths (24) of the through-flow openings (10) there is arranged in each case a projection (26) projecting in the direction of the gas volume (7), so that each mouth (24) of a through-flow opening (10) and each sealing elevation (23) completely surrounding the through-flow opening (10) is provided in each case at an axial end of one of the projections (26) facing the gas volume (7).

11. Injection valve according to claim 10, characterized in that the projections (26) are arranged at a distance from one another.

12. Injection valve according to one of claims 1 to 11, characterized in that at least one mouth (24) of a flow opening (10) is designed as a circular arc section.

13. Injection valve according to one of claims 1 to 11, characterized in that at least one mouth (24) of a flow opening (10) in the end face (20) is radially aligned.

14. Injection valve according to one of claims 1 to 11, characterized in that the mouth (24) has a radial leg (24a, 24b) which is connected to a section (24c) of the mouth (24) extending in the circumferential direction.

15. Injection valve according to one of claims 1 to 11, characterized in that the mouth (24) has two radial legs (24a, 24b), each of which is connected to a section (24c) of the mouth (24) extending in the circumferential direction.

16. Injection valve according to one of claims 1 to 15, characterized in that at least one sealing elevation (23) is rounded in the direction of the gas volume (7).

17. Injection valve according to one of claims 1 to 16, characterized in that at least one edge of at least one stop (25) facing the gas volume (7) is rounded in the direction of the gas volume (7).