Device for an exhaust system of an internal combustion engine and internal combustion engine with at least one such device

Abstract

The invention relates to a device (18) for an exhaust tract (10) through which exhaust gas from an internal combustion engine flows, with at least one component (20) which has at least one flow opening (28) through which a fluid can flow, wherein a closing device (34) is provided which has an actuator (36), at least one spring element (38) and a closing element (40) associated with the component (20), which can be rotated by means of the actuator (36) about a rotation axis (42) relative to the component (20) between a closed position (V) and a release position (F).

Description

The invention relates to a device for an exhaust tract of the internal combustion engine through which exhaust gas of an internal combustion engine can flow, according to the preamble of patent claim 1.Motor vehicles with internal combustion engines are known from the general state of the art and in particular from series vehicle construction. The respective internal combustion engine, also referred to as an internal combustion engine or an internal combustion engine, has a respective exhaust tract, which is also referred to as an exhaust system. Exhaust gas of the respective internal combustion engine can flow through the respective exhaust tract. Usually, at least one component is arranged in the respective exhaust tract, which component has at least one throughflow opening. The exhaust gas can flow through the flow opening, which may be undesirable at least in an operating state of the internal combustion engine. In other words, for example, the exhaust gas flowing through the exhaust tract can flow through the flow opening and thus flow into the component via the flow opening, which can be undesirable at least in the aforementioned operating state. This is because the exhaust gas may contain particles such as soot particles, which, because the exhaust gas can flow through the flow opening, can contaminate at least a portion of the component in an undesirable manner. As a result, a function of the component can be impaired in an undesirable manner.DE 10 2020 126 773 B3, DE 693 05 139 T2 and DE 10 2022 002 118 B3 each show, considered per se, a device for an exhaust tract through which exhaust gas of an internal combustion engine can flow, having at least one component which has at least one flow opening through which a fluid can flow.It is therefore an object of the present invention to provide a device for an exhaust tract of an internal combustion engine and an internal combustion engine for a motor vehicle, so that an undesirable impairment of function can be avoided.This object is achieved by a device having the features of patent claim 1 and by an internal combustion engine having the features of patent claim 9. Advantageous embodiments with expedient developments of the invention are specified in the other claims.A first aspect of the invention relates to a device for an exhaust tract of the internal combustion engine, also referred to as an internal combustion engine or an internal combustion engine, through which exhaust gas of an internal combustion engine, also referred to as an internal combustion engine and for example a reciprocating piston engine, and therefore an internal combustion engine designed as a reciprocating piston engine, can flow. This means that the internal combustion engine in its completely produced state has the exhaust tract through which the exhaust gas of the internal combustion engine can flow. In addition, the internal combustion engine in its completely manufactured state has the device which is arranged in the exhaust tract. The device has at least one component. Thus, the internal combustion engine in its completely produced state has the at least one component which is arranged at least partially in the exhaust tract in the completely produced state of the internal combustion engine. The component has at least one flow opening through which a fluid, in particular a gas, can flow, which is formed, for example, in a wall of the component, which wall is formed in particular as a solid body. The flow opening is thus a through opening which penetrates the wall, for example.For example, it is possible that, in particular when the fluid is the exhaust gas, in a first operating state of the internal combustion engine the exhaust gas, which flows through the exhaust tract, for example, in the first operating state, flows through the flow opening in the first operating state. In this regard, it may be desirable that in a second operating state of the internal combustion engine, in particular when the fluid is the exhaust gas, it is prevented, that is to say it is prevented, that in the second operating state the exhaust gas, which in the second operating state flows through the exhaust tract, flows through the flow opening. It is furthermore conceivable, in particular when the fluid is a fluid different from the exhaust gas of the internal combustion engine, in the first operating state of the internal combustion engine, in a first operating state of the internal combustion engine the exhaust gas flows through the exhaust tract, the fluid flows through the throughflow opening and in the process for example the fluid flows out of the component via the throughflow opening, whereby for example in the first operating state it is avoided that in the first operating state the exhaust gas of the internal combustion engine flows through the throughflow opening and the exhaust gas of the internal combustion engine flows into the component via the throughflow opening. For this purpose, it is provided, for example, that the component is activated, i.e., operated, in the first operating state of the internal combustion engine. For example, it is conceivable that in the second operating state of the internal combustion engine the component is deactivated, in particular continuously and thus without interruption, so that the fluid does not flow through the flow opening, in particular when it is a fluid different from the exhaust gas, wherein, for example, in the second operating state of the internal combustion engine the exhaust gas flows through the exhaust tract. If no corresponding countermeasure is taken, in the second operating state of the internal combustion engine, in the second operating state of the internal combustion engine, the exhaust gas flows through the exhaust tract, but the fluid does not flow through the throughflow opening, the exhaust gas can flow through the throughflow opening, which can be undesirable, however. In particular, it may therefore be undesirable in the second operating state for the exhaust gas to flow through the throughflow opening, since undesirable adverse effects on a desired function of the component may then occur, for example. This may be due to the fact that particles, in particular soot particles, may optionally be present in the exhaust gas. Because, for example, in the second operating state of the internal combustion engine, the exhaust gas can flow through or flows through the throughflow opening if no corresponding countermeasure is taken, the particles contained in the exhaust gas can impair the function of the component.In order to be able to reliably prevent an undesired impairment of the function of the component, it is provided according to the invention that the device has a closure device. The closure device has an actuator which is provided in particular in addition to the component and which can be operated electrically and / or hydraulically and / or pneumatically and / or electromechanically, for example. In particular, the actuator can be designed as an electric motor. Furthermore, the closure device has at least one spring element. The spring element is preferably designed as a solid body and thus as a mechanical spring. In particular, the spring element is provided in addition to the actuator. The closure device also has a closure element which is assigned to the component and is preferably designed as a solid body and which is rotatable by means of the actuator about an axis of rotation relative to the component between a closure position and a release position. In the closed position, a projection of the closure element engages in the throughflow opening of the component, so that in the closed position the projection is arranged at least partially in the throughflow opening, for example in such a way that the projection penetrates the throughflow opening, in particular completely. In addition, the spring element provides a spring force at least in the closed position, which spring force acts in particular along the axis of rotation. In the closed position, the closure element is tensioned, in particular directly, against the component by means of the spring force, whereby the projection is held in engagement with the throughflow opening. As a result, the flow opening is closed, that is to say is fluidically blocked, such that the exhaust gas cannot flow through the flow opening, in particular even when the internal combustion engine generates or provides the exhaust gas and therefore the exhaust gas flows through the exhaust tract. In addition, in the closed position, the fluid cannot flow through the flow opening, so that, for example, the closure element is in the closed position, while the component is deactivated. With regard to the aforementioned, second operating state of the internal combustion engine, it can be provided, for example, that in the second operating state of the internal combustion engine the component is deactivated, in particular continuously and thus without interruption, so that, for example, the component does not provide the fluid, in particular when the fluid is a fluid different from the exhaust gas, when the component is deactivated. Thus, for example, in the second operating state of the internal combustion engine, the closure element can be rotated into the closure position or the closure element can be in the closure position in the second operating state of the internal combustion engine, in particular continuously and thus without interruption, so that in the second operating state it is prevented that the exhaust gas flows through the flow opening, in particular both when the fluid is the exhaust gas and when the fluid is a fluid different from the exhaust gas.It can be provided that in the first operating state of the internal combustion engine the component is activated, in particular continuously and thus without interruption, and is thus operated, wherein for example in the first operating state the exhaust gas can flow through the flow opening. It is furthermore conceivable that when the component is activated, the component provides the fluid, which is different from the exhaust gas in particular, so that when the component is activated, the fluid flows through the flow opening and thus prevents the exhaust gas from flowing through the flow opening. Thus, for example, in the first operating state of the internal combustion engine, the closure element is or is rotated into the release position. In the release position, the projection is arranged at least partially, in particular completely, offset with respect to the throughflow opening in the circumferential direction of the component and of the closure element running about the axis of rotation, and in the release position, a passage opening of the closure element arranged next to the projection in the circumferential direction is arranged in at least partial, in particular complete, overlap with the throughflow opening, as a result of which the throughflow opening is released. Thus, in the release position, the fluid can flow through the flow opening and also through the flow opening, so that, for example, in the first operating state, the component can be operated advantageously and as desired. The flow opening is a first through opening or is also referred to as a first through opening. If, for example, it is provided that the flow opening is formed in the aforementioned wall of the component, the wall of the component, which wall is preferably formed as a solid body, is also referred to as a first wall. For example, it is provided that the through-opening of the closure element, also referred to as a second through-opening, is formed in a second wall of the closure element, preferably formed as a solid body, so that the second through-opening preferably penetrates completely through the second wall. If the through opening is mentioned above and below, this is to be understood as meaning the through opening of the closure element, unless otherwise stated. By means of the closure device, it is possible to avoid in a manner which is as required and reliable, that an excessive introduction of dirt, in particular introduction of soot, on and / or into the component occurs, since the throughflow opening can be closed in a manner which is as required and reliable, that is to say can be fluidically blocked and in particular sealed, by means of the closure device, in particular in such a way that, in the closed position, the exhaust gas cannot flow through the throughflow opening. If an operation of the component is provided or desired, that is to say if the component is operated, for example, the closure element is or is rotated into the release position and is therefore moved, such that the fluid can flow through the throughflow opening and the passage opening. If the fluid is, for example, a fluid different from the exhaust gas, it is conceivable, for example, for the component to provide the fluid during its operation, wherein the fluid flows through the flow opening and thereby flows, for example, into an exhaust gas duct of the exhaust gas tract, in particular while the exhaust gas flows through the exhaust gas duct. Thus, the fluid can be mixed with the exhaust gas of the internal combustion engine. In or through the closed position, however, it is avoided that the exhaust gas flows through the flow opening, so that an undesired functional impairment of the component can be reliably avoided. Due to the fact that the spring element provides the spring force at least in the closed position, by means of which the closure element is tensioned, in particular directly, against the component and is thus held in, in particular direct, support contact with the component, a secure closing, in particular sealing of the flow opening, can be ensured. It is thus possible to prevent an excessive amount of the exhaust gas from flowing through the flow opening, in particular even when the exhaust gas flows through the exhaust tract or the exhaust gas duct. Because the projection engages in the flow opening in the closed position and because the closure element is tensioned against the component by means of the spring force in the closed position, the closure element is a spring-mounted rotary closure which, in the closed position, closes the flow opening, which is configured as an inlet opening or outlet opening, for example, in a force-fit and form-fit manner. As a result, the component can be protected from an excessive introduction of dirt, in particular introduction of soot. It can be seen that the closure element is an efficient closure against an excessive introduction of dirt, wherein the device can be used particularly advantageously in high-temperature zones within the exhaust tract. A simple and thus robust construction of the closure device can be realized, wherein at the same time an efficient and effective closure of the flow opening can be achieved.In order to be able to realize an advantageous functionality of the device even over a long service life and thus to be able to open or close the throughflow opening as required and thus optionally, it is provided in an embodiment of the invention that in the open position the projection bears along the axis of rotation, in particular directly, against a partial region of the component, in particular the first wall of the component, which partial region adjoins the throughflow opening in the circumferential direction, as a result of which respective further partial regions of the component and of the closure element, which partial region adjoins the projection and the throughflow opening in the circumferential direction and lies opposite one another along the axis of rotation, are held at a distance from one another, in particular running along the axis of rotation, in particular in such a way that air is arranged, in particular exclusively, between the further partial regions. Thus, in the release position, the projection functions as a spacer element, so that an excessively large, planar contact between the component and the closure element can be avoided. In particular, in this way, in the release position, an, in particular direct, contact between the component and the closure element is limited to a point, line and / or circular contact between the projection and the component. This makes it possible to prevent the component and the closure element from forming a difficultly detachable or non-detachable connection, for example by oxidation, freezing, clamping jaws, etc., and the closure element from being able to be rotated relative to the component.It has been found to be particularly advantageous if the spring element provides a spring force in the release position, by means of which the closure element is tensioned, in particular directly, along the axis of rotation against the component, in particular via the projection. As a result, a secure and defined support contact of the closure element on the component can be realized, in particular via the projection, so that a desired function of the closure element can also be ensured over a long service life.A further embodiment is distinguished in that the projection is designed as a spherical segment and is thus spherical. On the one hand, the flow opening can thereby be safely blocked in the closed position. On the other hand, the closure element can thereby be held in the release position at an advantageous and defined distance from the component by means of the projection, and an excessively large, planar contact between the closure element and the component in the release position can be avoided.It has proven particularly advantageous here if the throughflow opening is circular. As a result, the throughflow opening can be reliably fluidically blocked, in particular sealed, by means of the projection in the closed position. A further embodiment is characterized in that the largest diameter of the ball segment is greater than the largest diameter of the circular flow opening. As a result, the throughflow opening can be closed reliably and in a defined manner, and an excessively large, planar contact between the closure element and the component in the release position can be avoided, with the result that a high functional integrity reliability of the device can be represented. For example, the protrusion is produced by embossing. Furthermore, it is conceivable that the flow opening is produced by drilling and is thus formed as a bore.In a further, particularly advantageous embodiment of the invention, the component is a first component of the device. In other words, the component is also referred to as a first component. The closure element is a second component of the device or is also referred to as a second component of the device. One of the structural elements has a first stop and a second stop, which is spaced apart from the first stop and faces the first stop in the circumferential direction running about the axis of rotation. In particular, the first stop and the second stop are formed by respective wall regions of the one component, which wall regions are in particular formed as solid bodies. The first stop and the second stop each directly delimit in the circumferential direction a recess of the structural element arranged in the circumferential direction between the stops and also referred to as a pocket. The other component has a stop projection which engages into the recess and is provided in particular in addition to the projection. The stop protrusion includes a third stop facing the first stop in the circumferential direction and a fourth stop facing the second stop in the circumferential direction. In addition, the fourth stop faces away from the third stop in the circumferential direction. The release position is a first position of the closure element or is also referred to as the first position of the closure element. The closure position is a second position of the closure element or is also referred to as a second position of the closure element. In one of the positions, the first stop abuts directly against the third stop in the circumferential direction, and in the one position, the second stop is spaced apart from the fourth stop in the circumferential direction. In the other position, the second stop abuts the fourth stop directly in the circumferential direction, and in the other position, the first stop is spaced apart from the third stop in the circumferential direction. Thus, the closure element can be moved by means of the actuator in a simple and robust manner, for example about the axis of rotation in a first rotational direction relative to the component, and in particular only until the first stop comes into direct support contact with the third stop, for example. Furthermore, for example, by means of the actuator, the closure element can be rotated about the axis of rotation relative to the component in a second direction of rotation opposite the first direction of rotation, and in particular only until the second stop comes into direct support contact with the fourth stop. As a result, the closure element can be rotated about the axis of rotation relative to the component easily, quickly and robust into the positions and thus moved, so that a fast, robust and demand-based rotation and thus movement of the closure element can be produced. A particularly advantageous functionality of the device can thus be ensured.In order to realize a particularly robust functionality of the device, it has proven to be particularly advantageous if the stop projection protrudes from regions of the other component adjoining the stop projection in the circumferential direction in the radial direction of the components running perpendicular to the axis of rotation.In a further, particularly advantageous embodiment of the invention, it is provided that the component is a burner which has a combustion chamber in which a mixture comprising air and a fuel is to be ignited and thereby burned. As a result, for example, when the burner is activated and is thus operated, the burner provides a fluid, also referred to as burner exhaust gas, and in particular, in addition to the exhaust gas, also referred to as engine exhaust gas, provided for the internal combustion engine. For example, the burner is activated in the first operating state of the internal combustion engine, so that the burner is operated in the first operating state of the internal combustion engine. For example, in the first operating state, the internal combustion engine provides the exhaust gas (engine exhaust gas) for the purpose, so that in the first operating state and thus while the burner is being operated, the engine exhaust gas flows through the exhaust tract and thus in particular through the exhaust gas duct. In the first operating state, the burner provides the burner exhaust gas, which in the first operating state can flow through the flow opening and also the flow opening in the first operating state, in particular continuously, by virtue of the fact that the closure element is in the release position in the first operating state. The burner exhaust gas can thus flow out of the combustion chamber via the flow opening and via the through opening and flow into the exhaust gas duct, as a result of which, for example, the engine exhaust gas can be heated or kept warm. As a result, at least one exhaust gas aftertreatment component arranged in the exhaust tract can be heated or kept warm by means of the burner exhaust gas, with the result that particularly low-emission operation of the internal combustion engine can be ensured in a particularly simple manner.For example, the burner is deactivated in the second operating state of the internal combustion engine, so that the burner does not provide the burner exhaust gas in the second operating state of the internal combustion engine. In this case, it is provided in particular that, in the second operating state of the internal combustion engine, the closure element is in the closure position, which is advantageous in particular when, in the second operating state of the internal combustion engine, the engine exhaust gas flows through the exhaust tract and thus through the exhaust duct. Thus, in the second operating state, i.e. while the burner is deactivated, it is possible to prevent the exhaust gas from the exhaust gas passage from flowing through the flow opening and thus flowing into the combustion chamber, so that it is possible to prevent the burner from being excessively exposed to dirt, such as particles originating from the exhaust gas, for example soot particles.Components in the interior of the burner can thus advantageously be protected from the introduction of soot. At least one injector and a spark plug or glow plug and an air supply for forming and igniting a combustible mixture project into the combustion chamber of the burner. Furthermore, a closure element for the air supply or sensors can be provided. Soot particles attached to the components of the burner can impair the function of the components.A second aspect of the invention relates to an internal combustion engine, also referred to as an internal combustion engine or internal combustion engine, for a motor vehicle, also referred to simply as a vehicle, which has the internal combustion engine at least in its completely produced state and can be driven by means of the internal combustion engine. The motor vehicle is preferably designed as a motor vehicle, in particular a passenger car, or as a commercial vehicle. The internal combustion engine has an exhaust tract through which the exhaust gas of the internal combustion engine can flow and which is also referred to as an exhaust system, and a device according to the first aspect of the invention. The device is arranged in the exhaust tract. The component is arranged at least partially in an exhaust gas duct of the exhaust tract through which the exhaust gas can flow, such that the flow opening is arranged in the exhaust gas duct. Thus, in the release position of the closure element, the fluid can advantageously flow through the flow opening and thus, for example, flow from the exhaust gas channel into the component or, conversely, flow from the component into the exhaust gas channel. In the closed position, however, it can be avoided that the exhaust gas flowing through the exhaust gas duct flows through the flow opening. Advantages and advantageous configurations of the first aspect of the invention are to be regarded as advantages and advantageous configurations of the second aspect of the invention and vice versa.Further advantages, features and details of the invention will become apparent from the following description of a preferred exemplary embodiment and with reference to the drawing. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination but also in other combinations or alone without departing from the scope of the invention.The drawing shows in: FIG. 1 shows a schematic and sectional perspective view of a section of an exhaust tract of an internal combustion engine of a motor vehicle; FIG. 2 shows a schematic perspective view of a detail of a closure element of a device arranged in the exhaust tract; FIG. 3 shows a detail of a further schematic and sectional perspective view of the exhaust tract; FIG. 4 shows a schematic and partially cut perspective view of the device; FIG. 5 shows a detail of a further schematic and partially cut perspective view of the device; FIG. 6 shows a schematic longitudinal sectional view of the device in a detail; FIG. 7 shows a schematic perspective view of a portion of the device; FIG. 8 shows a detail of a further schematic perspective view of the device; FIG. 9 shows a detail of a further schematic and partially cut perspective view of the exhaust tract; and FIG. 10 shows a schematic perspective view of a spring element of the device.In the figures, identical or functionally identical elements are provided with identical reference symbols.FIG. 1 shows a detail in a schematic and partially cut perspective view of an exhaust tract 10 of an internal combustion engine, also referred to as an internal combustion engine or an internal combustion engine, and for example, as a reciprocating piston engine, and therefore as a reciprocating piston engine, of a motor vehicle, also referred to simply as a vehicle. This means that the motor vehicle has the internal combustion engine and can be driven by means of the internal combustion engine. The internal combustion engine has the exhaust tract 10 and, in its fired operation, provides an exhaust gas, also referred to as engine exhaust gas, through which the exhaust tract 10 can be flown. In FIG. 1, an arrow 12 illustrates a flow of the engine exhaust gas through the exhaust tract 10. The exhaust tract 10 has an exhaust line 16 which is in particular embodied as a solid body and is also referred to as an exhaust pipe and delimits the exhaust gas duct 14, in particular directly. A device 18 is arranged in the exhaust tract 10. The device 18 has a component 20 partially illustrated in FIG. 1. The component in the present exemplary embodiment according to FIGS. 1 to 10 is provided as a burner 20, which can be supplied with air and an in particular liquid fuel. The burner 20 has a combustion chamber 22, in which a mixture comprising the air and the fuel can be ignited and thereby burned. In other words, if the burner 20 is activated so that the burner 20 is operated, the mixture is burned in the combustion chamber 22. As a result, the burner 20 provides an exhaust gas, also referred to as burner exhaust gas. The burner exhaust gas is a fluid or is also referred to as a fluid. It can be seen from FIG. 1 that the burner 20 has a chamber element 24 which is in particular embodied as a solid body, wherein the combustion chamber 22 is delimited, in particular directly, by the chamber element 24, in particular by an inner-circumferential lateral surface 26 of the chamber element 24. It can be seen particularly well in conjunction with FIGS. 5, 6 and 7 that the chamber element 24 and thus the burner 20 (component) have a plurality of components.The exhaust gas from the combustion chamber 22 can flow through flow openings 28, which can be flowed through in particular basically or when the flow openings 28 are opened. It can be seen in particular that the respective flow opening 28 is a respective first passage opening which is formed in a first wall 30 of the chamber element 24, which wall is formed in particular as a solid body and completely penetrates the first wall 30. The combustion chamber 22 is directly and partially delimited by the wall 30. In FIG. 1, it is illustrated by an arrow 13 that the air and fuel are supplied to the combustion chamber 22, and are therefore introduced into the combustion chamber 22, so that the combustible mixture can be formed in the combustion chamber 22 and can be ignited in the combustion chamber by means of an ignition device, not shown in detail, in the form of a spark plug or a glow plug.If the burner 20 provides the burner exhaust gas and the burner exhaust gas flows through the flow openings 28 and thus out of the combustion chamber 22 and thereby into the exhaust gas duct 14, while the engine exhaust gas flows through the exhaust gas duct 14, the burner exhaust gas is mixed with the engine exhaust gas, whereby an exhaust gas mixture is produced. The engine exhaust gas can be heated by means of the burner exhaust gas, so that the exhaust gas mixture has a higher temperature than the engine exhaust gas considered alone. In FIG. 1, an arrow 32 illustrates a flow of the exhaust gas mixture, wherein the exhaust gas mixture can flow, for example, to an exhaust gas aftertreatment elements arranged downstream of the burner 20 and arranged in the exhaust tract 10 and can flow through the exhaust gas aftertreatment elements, as a result of which the exhaust gas aftertreatment component 33 is heated, that is to say heated. In the exemplary embodiment shown, the exhaust gas aftertreatment component 33 is formed, for example, in the form of a diesel oxidation catalyst downstream of the burner 20. As a result, the exhaust gas aftertreatment component designed as a catalyst or comprising at least one catalyst can be brought quickly, effectively and efficiently to its light-off temperature, also referred to as light-off temperature, or above the light-off temperature, wherein, starting from the light-off temperature, the engine exhaust gas, in the present case the exhaust gas mixture, can be effectively and efficiently post-treated by means of the exhaust gas aftertreatment component.However, if the burner is deactivated, for example, at least in an operating state of the internal combustion engine, so that the burner 20 is not activated, at least in the operating state of the internal combustion engine, and is therefore not operated and thus does not provide the burner exhaust gas, and if, however, the engine exhaust gas flows through the exhaust gas duct 14 in the at least one operating state, it may be desirable to prevent the engine exhaust gas flowing through the exhaust gas duct 14 from being able to flow through the flow openings 28. For this purpose, the device 18 has a closure device 34, which has an actuator 36, which is illustrated particularly schematically in FIG. 1 and is provided in particular in addition to the burner 20. Furthermore, the closure device 34 has a spring element 38 which can be seen from FIGS. 9 and 10 and which is designed in the present case as a solid body and thus as a mechanical spring. The closure device 34 also has a closure element 40 which can be seen particularly well from FIG. 2 and is assigned to the burner 20 (component) and which can be rotated by means of the actuator 36 about an axis of rotation 42 relative to the burner 20 and in this case in particular relative to the chamber element 24 between a closure position shown in FIGS. 1 and 3 and also designated as closed position and a release position shown in FIGS. 4 to 7 and also designated as open position. It can be seen particularly well from FIGS. 1 to 3 that both a respective projection 44 of the closure element 40 and a respective second through-opening 46 of the closure element 40 embodied in the present case as a solid body are assigned to the respective through-flow opening 28.The chamber element 24, the burner 20 as a whole and the closure element 40 are collectively also referred to as structural elements. The flow openings 28 are arranged in succession and thus next to one another in the circumferential direction of the components running about the axis of rotation 42, in particular in such a way that the flow openings 28 are arranged uniformly distributed in the circumferential direction. The circumferential direction runs around the axis of rotation 42 and is illustrated in FIG. 2 by a double arrow 48. In particular, the flow openings 28, in particular their center points, are arranged on a first circle, wherein their first center point lies on the axis of rotation 42. In particular, the first circle has a first diameter. In the exemplary embodiment shown in the figures, the respective flow opening 28 is circular. The projections 44 and the through-openings 46 of the closure element 40 are arranged alternately in succession in the circumferential direction of the components running about the axis of rotation 42, in particular in such a way that the projections 44 and the through-openings 46, in particular their respective centers, are arranged on a second circle, the second center of which lies on the axis of rotation 42. The second circle has a second diameter. Preferably, it is provided that the second diameter corresponds to the first diameter or vice versa. The respective through-opening 46 is circular in the present case. The respective projection 44 is designed in the present case as a respective ball segment. For example, the respective flow opening 28 has a respective first inner circumference, in particular a first respective inner diameter. For example, the respective through-opening 46 has a respective second inner circumference, in particular a respective second inner diameter. Preferably, the respective first inner circumference, in particular the respective first inner diameter, corresponds to the respective second inner circumference, in particular the respective second inner diameter. Furthermore, it is preferably provided that the largest diameter of the respective ball segment 44 is larger than the largest diameter of the respective flow opening 28.In the closed position of the closure element 40 denoted by V, the respective projection 44 engages in the respective throughflow opening 28 to which the respective projection 44 is assigned. In addition, in the closed position V, the spring element 38 provides a spring force illustrated in FIG. 3 by a force arrow PF, by means of which the closure element 40 is tensioned against the chamber element 24 along the axis of rotation 42, whereby the respective projection 44 is held in engagement with the respective throughflow opening 28 to which the respective projection 44 is assigned. As a result, in the closed position V, the, in particular all, flow openings 28 of the chamber element 24 are closed, and are therefore fluidically blocked, with the result that, for example, when the burner 20 is not operated while the engine exhaust gas flows through the exhaust gas duct 14, the engine exhaust gas from the exhaust gas duct 14 cannot flow through the flow openings 28 and therefore cannot flow into the combustion chamber 22. In the release position of the closure element 40 shown in FIG. 4 and designated F, the respective projection 44 is arranged at least partially offset in the circumferential direction of the components extending about the axis of rotation 42 with respect to the respective throughflow opening 28 to which the respective projection 44 is assigned, and in the release position F the respective throughflow opening 46 of the closure element 40 arranged in the circumferential direction with respect to the respective projection 44 is arranged in at least partial overlap with the respective throughflow opening 28 to which the respective throughflow opening 46 is assigned, as a result of which the throughflow openings 28 are released in the release position F. If the burner 20 is thus operated, so that the burner 20 provides the burner exhaust gas, and if the closure element 40 is meanwhile located in the release position F, the burner exhaust gas can flow through the flow openings 28 from the combustion chamber 22 and thus flow out of the combustion chamber 22 and flow into the exhaust gas duct 14. Because the burner 20 provides the burner exhaust gas, and because the burner exhaust gas flows through the enabled flow openings 28, while the burner 20 is being operated, the exhaust gas from the exhaust passage 14 cannot flow through the flow openings 28. Thus, excessive impingement of soot contained in the engine exhaust gas on the burner 20 and, in particular, on the combustion chamber 22 of the burner 20 can be avoided.In FIG. 4, for example, an arrow 50 illustrates a first direction of rotation extending about the axis of rotation 42, in which direction, for example, the closure element 40 is rotated by means of the actuator 36 in order to rotate the closure element 40 from the release position F into the closure position V relative to the burner 20 and thus to move it. For example, an arrow 52 in FIG. 5 illustrates a second rotational direction which extends about the rotational axis 42 and is opposite the first rotational direction and in which, for example, the closure element 40 is rotated by means of the actuator 36 relative to the burner 20 and thus relative to the chamber element 24 in order to rotate the closure element 40 from the closure position V into the release position F and thus to move it.It can be seen particularly well from FIGS. 2, 4, 5 and 6 that the respective through-opening 46 is formed in a second wall 54 of the closure element 40 formed as a solid body and penetrates the wall 54 completely, in particular viewed along the axis of rotation 42. This can also be transferred to the respective flow opening 28 and the first wall 30 of the chamber element 24 of the burner 20. It can be seen particularly well from FIG. 6 that in the release position F the respective projection 44 bears along the axis of rotation 42 directly against a respective subregion TB of the chamber element 24, in particular the wall 30, adjoining the respective throughflow opening 28 in the circumferential direction, as a result of which respective further subregions TB 2 of the components, therefore of the closure element 40 and of the burner 20 and very in particular of the closure element 40 and of the chamber element 24, adjoining the respective throughflow opening 28 in the circumferential direction and lying opposite one another along the axis of rotation 42 are held at a distance D from one another, in particular running along the axis of rotation 42. In addition, it is provided in the present case that, in the closed position V, the respective projection 44 touches the chamber element 24 along a line or a circle, so that, in the closed position V, between the closure element 40 and the chamber element 24, there is at most one line or circle touch per projection 44. This makes it possible to prevent the components from baking on one another and / or otherwise sticking to one another, so that a secure and need-based rotation of the closure element 40 relative to the burner 20 can be ensured even over a long service life of the device 10. The respective projection 44 which is embodied in the present case as a spherical segment and is thus spherical is produced, for example, by stamping and thus an stamped element. For example, the respective flow opening 28 and / or the respective flow opening 46 is designed as a respective bore.It can be seen particularly well from FIG. 6 that the closure element 40 has a first closure part 56 and a second closure part 58, which are connected to one another in a rotationally fixed manner, in particular in such a way that the closure parts 56 and 58 are formed separately from one another and are connected to one another or in such a way that the closure parts 56 and 58 are formed integrally with one another, and are therefore formed from a single piece. For example, the closure part 58 is a shaft or axis, wherein the closure part 58 is rotatable, for example, about the axis of rotation 42 relative to the burner 20. A sheath element 60 is assigned to the closure part 58, which can be a component of the closure element 40. For example, the casing element 60 with the closure parts 56 and 58 is rotatable about the axis of rotation 42 relative to the burner 20. It is furthermore conceivable for the closure parts 56 and 58 and thus the closure element 40 to be rotatable about the axis of rotation 42 relative to the burner 20 and relative to the casing element 60. It can be seen that the casing element 60 completely surrounds at least one length region L of the closure part 58 in the circumferential direction and is spaced apart from the closure part 58 in the radial direction of the components which runs perpendicular to the axis of rotation 42 and is illustrated by a double arrow 62, with the result that a gap S which is designed as an air gap is arranged in the radial direction of the components between the closure part 58 and the casing element 60 and is bounded in the radial direction outwards, in particular directly, by the casing element 60, in particular by an inner circumferential lateral surface of the casing element 60, and in the radial direction inwards, in particular directly, by the closure part 68, in particular by an outer circumferential lateral surface of the closure part 58. In this case, the gap S surrounds at least the length region L of the closure part 58 completely circumferentially in the circumferential direction. As a result, the closure part 58 is insulated by means of the gap S, and is therefore insulated from an air gap and is thus protected from excessive heating, and is therefore protected from overheating. Thus, the sleeve element 60 is, for example, a sleeve which completely surrounds at least the length region L of the closure part 58 in the circumferential direction, specifically forming the gap S.The closure element 40, in particular the closure part 56, has a, for example, turned-over edge 64, which is explained in more detail below.It can be seen particularly well from FIGS. 7 and 8 that the closure element 40, in the present case the edge 64 of the closure element 40, has a first stop 66 and a second stop 68, which is spaced apart from the first stop 66 in the circumferential direction and faces the first stop 66. As a result, the stops 66 and 68 delimit in the circumferential direction a recess, which is arranged in the circumferential direction between the stops 66 and 68 and is referred to as pocket 70, of the closure element 40, in particular of the edge 64. The chamber element 24 and thus the burner 20 have a stop projection 72, which engages in the pocket 70 and is provided in addition to the projections 44 and has a third stop 74, which faces the first stop 66 in the circumferential direction, and a fourth stop 76, which faces the second stop 68 in the circumferential direction and faces away from the third stop 74 in the circumferential direction. In the release position F shown in FIG. 7, the stops 66 and 74 bear directly against one another in the circumferential direction, and the stops 68 and 76 are spaced apart from one another along the circumferential direction. In the closed position V shown in FIG. 8, the stops 68 and 76 bear directly against one another in the circumferential direction, and the stops 66 and 74 are spaced apart from one another along the circumferential direction. It can also be seen from FIGS. 7 and 8 that the stop projection 72 projects outwards in the radial direction of the structural elements from regions B 2 of the chamber element 24 which adjoin the stop projection 72, in particular directly, in the circumferential direction and thus away from the combustion chamber 22.It is preferably provided that the spring element 38 also provides a spring force in the release position F, by means of which the closure element 40 is tensioned via the projections 44 against the chamber element 24, in particular against the first wall 30. This spring force, which is provided by the spring element 38 in the release position F, is illustrated in FIG. 4 by a force arrow PF 2.In order, for example, to rotate the closure element 40 from the closure position V into the release position F relative to the chamber element 24, the closure element 40 is rotated about the axis of rotation 42 relative to the chamber element 24, for example, by a distance or a distance which is half the distance between two adjacent flow openings 28 running in the circumferential direction and also referred to as the hole spacing. If, for example, six flow-through openings 28 are provided, the flow-through openings 28 are arranged uniformly distributed in the circumferential direction, the aforementioned path amounts, for example, to 360° / 6 / 2=330 angular degrees. During the rotation of the closure element 40 from the closure position V into the release position F, the projections 44 designed as ball segments gradually leave the associated flow openings 28 and slide off at the chamber element 24, in particular at the wall 30, wherein the projections 44 act or function as ramps. As a result, the closure element 40 is moved translationally along the axis of rotation 42 and counter to the spring force of the spring element 38 a distance away from the chamber element 24 or the wall 30, also referred to as the base, i.e. displaced away. The distance D increases continuously in this case until the projections 44 have completely left the corresponding throughflow openings 28 and then in the release position F bear with a point contact on the wall 30, in particular on a surface of the wall 30 facing away from the combustion chamber 22, and in this case press in particular against the surface. If, in particular as a result of the closure element 40 being rotated from the release position F into the closure position V about the axis of rotation 42 relative to the chamber element 24, while the spring force of the spring element 38 illustrated by the force arrow PF presses the closure element 40 along the axis of rotation 42 against the chamber element 24, the projections 44 are moved further and further into the corresponding or associated flow openings 28, wherein the closure element 40 is again moved translationally a certain distance in the direction of the wall 30, that is to say is displaced, along the axis of rotation 42. Because the stop projection 72 engages in the corresponding pocket 70, the closure position V and the release position F are end positions of the closure element 40, which can be rotated into the respective end position about the axis of rotation 42 relative to the chamber element 24, but cannot be rotated beyond the respective end position. This embodiment makes it possible to clearly define the rotational movements of the closure element 40, the rotational movement of which is to be effected by means of the actuator 36, in the desired target position in each case. The actuator 36 can thus be switched off when the respective target position, and therefore the respective end position, is reached with a suitable measure which comprises, for example, monitoring a current consumption of the actuator 36. The configuration with a stop geometry in each of the closure position V and / or the release position F furthermore enables a spring return into the respective other position, which enables a very rapid change between the positions. In a further embodiment, it is conceivable to supplement the projections 44 penetrating into the flow openings 28 by additional segments, for example segments formed as ball segments, at another location in order to support the respective rotation of the closure element 40 into the closure position V or into the release position F.Preferably, a floating, flying or movable mounting of the closure element 40 is provided, in particular as viewed in the circumferential direction, so that, for example, the closure element 40 can oscillate, i.e. move back and forth, relative to the chamber element 24 about the axis of rotation 42 in particular via a spring suspension comprising, for example, the spring element 38, whereby, for example, tolerances and thermomechanical influences can be compensated.A bearing 78, which can be, for example, the aforementioned spring suspension and / or can comprise the spring element 38 and, for example, as illustrated in FIG. 9 by a double arrow 80, which allows the closure element 40 to be rotated back and forth about the axis of rotation 42 and relative to the chamber element 24. At least the following advantages can be realized by the device 18: all components located in geometries closed by the closure element 40 in the closure position V are simultaneously protected from excessive introduction of soot. The projections 44 allow centering of the closure element 40 relative to the chamber element 24, as a result of which large tolerances and a large play can also be permitted. Only a very small rotational movement is required to move the closure element 40 between the closure position V and the release position F, whereby excessive wear can be avoided. Respective contact surfaces between the wall 30 and the closure element 40 are limited to a minimum both in the closure position V and in the release position F and, in the process, for example, to spherical segments at edges of the throughflow openings 28 and to a respective crest of the respective projection 44 on or on the wall 30. In addition, automatic readjustment of elements that are tight with respect to one another can be realized in the event of wear. If, for example, the burner 20 is designed as a removable burner unit and / or if a service flap is used, replacement, repair and / or repair of the closure element 40 are possible at any time. Excessive disturbing influences in a flow guidance within the closed geometry, such as the combustion chamber 22, can be avoided.List of reference characters10 Exhaust tract 12 Arrow 13 Arrow 14 Exhaust gas duct 16 Exhaust gas duct 18 Device 20 Burner 22 Combustion chamber 24 Chamber element 26 Inner-circumferential-side lateral surface 28 Throughflow opening 30 First wall 32 Arrow 33 Exhaust gas aftertreatment component 34 Closure device 36 Actuator 38 Spring element 40 Closure element 42 Axis of rotation 44 Projection 46 Passage opening 48 Double arrow 50 Arrow 52 Arrow 54 Second wall 56 First closure part 58 Second closure part 60 Casing element 62 Double arrow 64 Edge 66 First stop 68 Second stop 70 Pocket 72 Stop projection 74 Third stop 76 Fourth stop 78 Bearing 80 Double arrow B 2 Regions D Distance F Release position PF Force arrow PF 2 Force arrow S Gap TB Partial region TB 2 Partial region V Closure position

Claims

Device (18) for an exhaust tract (10) through which exhaust gas from an internal combustion engine can flow, having at least one component (20) which has at least one flow opening (28) through which a fluid can flow, characterized bya closure device (34) which has: - an actuator (36); - at least one spring element (38); a closure element (40) which is assigned to the component (20) and can be rotated relative to the component (20) by means of the actuator (36) about an axis of rotation (42) between: o a closure position (V) in which a projection (44) of the closure element (40) engages in the throughflow opening (28) and the spring element (38) provides a spring force (PF) by means of which the closure element (40) is tensioned against the component (20) and the projection (44) is thereby held in engagement with the throughflow opening (28), as a result of which the throughflow opening (28) is closed; and; o a release position (F) in which the projection (44) is arranged at least partially offset with respect to the throughflow opening (28) in the circumferential direction (48) of the component (20) and of the closure element (40) running about the axis of rotation (42), and a throughflow opening (46) of the closure element (40) arranged next to the projection (44) in the circumferential direction (48) is arranged in at least partial overlap with the throughflow opening (28), as a result of which the throughflow opening (28) is released.Device (18) according to Claim 1, characterized in that, in the release position (F), the projection (44) bears along the axis of rotation 42) against a subregion (TB) of the component (20) adjoining the throughflow opening (28) in the circumferential direction (48), as a result of which respective further subregions (TB2) of the component (20) and of the closure element (40) adjoining the projection (44) and the throughflow opening (28) in the circumferential direction (48) and lying opposite one another along the axis of rotation (42) are held at a distance (D) from one another.Device (18) according to Claim 1 or 2, characterized in that the projection (44) is designed as a spherical segment.Device (18) according to Claim 3, characterized in that the throughflow opening (46) is of circular configuration.Device (18) according to claims 3 and 4, characterised in that the largest diameter of the ball segment is larger than the largest diameter of the flow opening (28).Device (18) according to one of the preceding claims, characterized in that: - the component (20) is a first structural element and the closure element (40) is a second structural element of the device (18); - one of the structural elements has a first stop (66) and a second stop (68), which stop is spaced apart from the first stop (66) in the circumferential direction (48) and faces the first stop (66), whereby the first stop (66) and the second stop (68) each directly delimit a recess (70) of the one structural element arranged between the first stop (66) and the second stop (68) in the circumferential direction (48); the other component has a stop projection (72) engaging in the recess (70), having a third stop (74) facing the first stop (66) in the circumferential direction (48) and a fourth stop (76) facing the second stop (68) in the circumferential direction (48) and facing away from the third stop (74) in the circumferential direction (48); the release position (F) is a first position and the closure position (V) is a second position of the closure element (40); the first stop (66) in the circumferential direction (48) abuts directly on the third stop (74) in one of the positions and the second stop (68) is spaced apart from the fourth stop (76) in the circumferential direction (48); and - in the other position, the second stop (68) bears directly against the fourth stop (76) in the circumferential direction (48), and the first stop (66) is spaced apart from the third (74) stop in the circumferential direction (48).Device (18) according to Claim 6, characterized in that the stop projection (72) projects in the radial direction (62) of the structural elements running perpendicularly to the axis of rotation (42) from regions (B2) of the other structural element adjoining the stop projection (72) in the circumferential direction (48).Device (18) according to one of the preceding claims, characterized in that the component (20) is a burner (20) which has a combustion chamber (22) in which a mixture comprising air and a fuel is to be ignited and thereby burned, as a result of which a burner exhaust gas for heating at least one exhaust gas aftertreatment component (33) arranged in the exhaust tract (10) is able to be provided.Internal combustion engine for a motor vehicle, having an exhaust tract (10) through which exhaust gas of the internal combustion engine can flow, and having a device (18) according to one of the preceding claims, which device is arranged in the exhaust tract (10), wherein the component (20) is arranged at least partially in an exhaust gas duct (14) of the exhaust tract (10) through which the exhaust gas can flow, in such a way that the throughflow opening (20) is arranged in the exhaust gas duct.

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