Burner for a motor vehicle and motor vehicle with at least one such burner

Abstract

A burner (12) has an inner swirl chamber (20) through which a first part of the air flows, which has a first swirl generating device (50) by means of which a swirl flow can be effected, and a first outlet opening (22) through which the first part of the air flowing through the inner swirl chamber (20) can be discharged, and through which the first part of the air can be discharged from the inner swirl chamber (20).The burner (12) has an outer swirl chamber (30) surrounding at least a length region of the inner swirl chamber (20) in the circumferential direction of the inner swirl chamber (20), through which a second part of the air can flow, which has a second swirl generating device (54) by means of which a swirl flow can be effected, and a second outlet opening (34) through which the second part of the air flowing through the outer swirl chamber (30) and the first part of the air flowing through the inner swirl chamber (20) and the first outlet opening (22) can flow, and through which the parts of the air can be introduced into a combustion chamber (16).The swirl generation devices (50, 54) are formed in one piece and the swirl channels (60) of the second swirl generation device (54), through which the second part of the air flows, are partially directly bounded by the second swirl generation elements (56) and partially by a first chamber element (36), which directly bounds at least a part of the combustion chamber (16).

Description

The invention relates to a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle can flow, according to the preamble of patent claim 1.DE 10 2021 001 584 A1 discloses a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle can flow. It is the object of the present invention to provide a burner for a motor vehicle and a motor vehicle having at least one such burner, so that particularly simple production of the burner can be realized.This object is achieved by a burner having the features of patent claim 1 and by a motor vehicle having the features of patent claim 10. Advantageous embodiments with expedient developments of the invention are specified in the other claims.A first aspect of the invention relates to a burner for an exhaust tract through which exhaust gas from an exhaust tract, which is also referred to as an internal combustion engine or internal combustion engine and is preferably designed as a reciprocating piston engine, that is to say as a reciprocating piston engine of a motor vehicle which is also referred to simply as a vehicle, can flow. This means that the motor vehicle, which can preferably be designed as a motor vehicle and very preferably as a passenger vehicle, has the internal combustion engine and the exhaust tract in its completely produced state and can be driven by means of the internal combustion engine. During a fired operation of the internal combustion engine, combustion processes take place in the internal combustion engine, in particular in at least one or more combustion chambers of the internal combustion engine, resulting in the exhaust gas of the internal combustion engine.The exhaust gas can flow out of the respective combustion chamber and into the exhaust tract and subsequently flow through the exhaust tract, which is also referred to as exhaust system. At least one component, such as an exhaust gas aftertreatment element for aftertreating the exhaust gas, may be arranged in the exhaust tract. The exhaust gas aftertreatment element is, for example, a catalyst, in particular an SCR catalyst, wherein, for example, a selective catalytic reduction (SCR) can be catalytically supported and / or effected by means of the SCR catalyst, such that, for example, the SCR catalyst is catalytically active for the SCR. In the selective catalytic reduction, any nitrogen oxides present in the exhaust gas are at least partially removed from the exhaust gas by the nitrogen oxides reacting with ammonia to form nitrogen and water in the selective catalytic reduction. The ammonia is provided, for example, by an in particular liquid reducing agent, which can be an aqueous urea solution. Furthermore, the exhaust gas aftertreatment element can be a particle filter, in particular a diesel particle filter, or can comprise a particle filter, in particular a diesel particle filter (DPF), it being possible for any particles contained in the exhaust gas, in particular soot particles, to be filtered out of the exhaust gas by means of the particle filter.The burner has a combustion chamber in which a mixture comprising air and a preferably liquid fuel can be ignited and thereby burned. As a result of the combustion of the mixture taking place in particular in the combustion chamber, a burner exhaust gas of the burner is generated, in particular in the combustion chamber. The burner exhaust gas can flow out of the combustion chamber, for example, and into the exhaust tract, i.e., for example, into an exhaust gas channel of the exhaust tract through which the exhaust gas of the internal combustion engine can flow, in particular at an introduction point which is arranged upstream of the aforementioned component, for example, in the flow direction of the exhaust gas of the internal combustion engine flowing through the exhaust tract or the exhaust gas channel. For example, the burner exhaust gas mixes with the exhaust gas of the internal combustion engine, the exhaust gas of which is also referred to as engine exhaust gas. As a result, the burner exhaust gas, in particular the burner exhaust gas mixed with the engine exhaust gas, can flow through the component, for example, as a result of which the component can be heated, that is to say heated. In particular, it is conceivable that the burner exhaust gas can flow out of the combustion chamber and into the exhaust tract or into the aforementioned exhaust tract and is thereby mixed with the exhaust gas of the internal combustion engine flowing through the exhaust tract and also referred to as engine exhaust gas and / or with a gas flowing through the exhaust tract, whereby the exhaust gas of the internal combustion engine or the gas is heated. In other words, this makes it possible to realize a particularly high temperature, also referred to as the exhaust gas temperature, of the exhaust gas of the internal combustion engine or of the gas. It is also conceivable for the gas to be, for example, air which flows through the exhaust tract or the exhaust gas channel, for example, in particular while the internal combustion engine is being dragged, that is to say while a fired operation of the internal combustion engine is not being carried out, with the internal combustion engine not providing any engine exhaust gas, with the gas, in particular the air, then being conveyed by the internal combustion engine into the exhaust tract and being conveyed through the exhaust tract, for example. The component can be heated by the high exhaust gas temperature, since the burner exhaust gas and, for example, engine exhaust gas or the gas flows through the component. Thus, for example, the burner exhaust gas is introduced from the combustion chamber at the aforementioned introduction point into the exhaust tract, in particular into the exhaust tract, and thus into the engine exhaust gas or gas flowing through the exhaust tract or the exhaust tract. For example, an ignition device, in particular an electrically operable ignition device, is provided, wherein the burner can comprise the ignition device. In particular, it is conceivable for the ignition device to be arranged at least partially in the combustion chamber. By means of the ignition device, in particular in the combustion chamber and / or using electrical energy, at least one ignition spark can be provided, i.e. generated, for igniting the mixture, so that in particular by means of the ignition spark the mixture can be ignited in the combustion chamber of the burner. The ignition device can be designed, for example, as a spark plug or as a glow plug.The burner has an inner swirl chamber through which a first part of the air forming the mixture, in particular in the combustion chamber, can flow and which brings about a swirling flow of the first part of the air, which swirl chamber is thus preferably arranged upstream of the combustion chamber in the flow direction of the first part of the air flowing through the inner swirl chamber. In the following, when the term air is used, unless otherwise stated, this is to be understood as meaning the air forming the mixture, in particular in the combustion chamber, that is to say the air from which the mixture is formed in particular together with the fuel. The inner swirl chamber has, in particular precisely, a first outflow opening through which the first part of the air flowing through the inner swirl chamber can flow, via which the first part of the air flowing through the first outflow opening can be discharged from the inner swirl chamber and introduced, for example, into the combustion chamber. Thus, in particular, the combustion chamber is arranged downstream of the inner swirl chamber in the flow direction of the first part of the air flowing through the inner swirl chamber. The feature that the inner swirl chamber brings about or can bring about a swirling flow of the first part of the air flowing through the inner swirl chamber is to be understood in particular as meaning that the first part of the air flows through the inner swirl chamber in a swirling manner, and therefore flows through at least a first partial region of the inner swirl chamber in a swirling manner, and / or the first part of the air only has its swirling flow at least in a first flow region which is arranged downstream of the inner swirl chamber and outside the inner swirl chamber and is arranged, for example, in the combustion chamber. In particular, it is conceivable for the first part of the air to flow out of the inner swirl chamber in a swirling manner via the first outflow opening and / or to flow into the combustion chamber in a swirling manner, so that it is very preferably provided that the first part of the air has its swirling flow at least in the combustion chamber. In particular, it is conceivable that the first part of the air already has its swirling flow in the inner swirl chamber, namely at least in the aforementioned at least one first partial region of the inner swirl chamber.For example, the burner can have an introduction element, in particular an injection element, which has at least or exactly one outlet opening through which the preferably liquid fuel can flow. In particular, it is conceivable for the introduction element to have a plurality of, in particular more than two, outlet openings through which the preferably liquid fuel can flow. By means of the introduction element, the fuel can be introduced, in particular injected, for example into the inner swirl chamber, in particular directly, such that the fuel, which is preferably liquid, can also be flown through by, in particular injected, the first outflow opening, for example, by the preferably liquid fuel which has emerged, in particular injected, from the introduction element via the outlet opening and is thereby introduced, in particular injected, directly into the inner swirl chamber. This means in particular that the first part of the air and, for example, also the fuel can flow through the first outflow opening along a first flow direction, in particular in the first flow direction, which is common to the first part of the air and the fuel, and can thereby flow out of the inner swirl chamber.Furthermore, the burner comprises an outer swirl chamber which surrounds at least one length region of the inner swirl chamber and in this case also preferably the first outflow opening in the circumferential direction of the inner swirl chamber, in particular in a completely circumferential manner. The circumferential direction of the inner swirl chamber extends, for example, around the aforementioned first flow direction, which extends, for example, in the axial direction of the inner swirl chamber and thus of the first outflow opening, and therefore coincides with the axial direction of the inner swirl chamber, the radial direction of which extends perpendicular to the axial direction of the inner swirl chamber, and thus the outflow opening. It is preferably provided that the inner swirl chamber ends at the first outflow opening or at its end in the flow direction of the first part flowing through the first outflow opening and thus for example in the flow direction of the fuel flowing through the first outflow opening, thus in the axial direction of the inner swirl chamber and thus of the first outflow opening. A second part of the air can flow through the outer swirl chamber, the axial direction of which coincides with the axial direction of the inner swirl chamber, and is designed to bring about a swirling flow of the second part of the air. This is to be understood in particular as meaning that the second part of the air flows in the outer swirl chamber in a swirling manner, and therefore flows through at least a second partial region of the outer swirl chamber in a swirling manner, and / or the second part of the air has its swirling flow in a second flow region arranged downstream of the outer swirl chamber in the flow direction of the second part of the air flowing through the outer swirl chamber, said second flow region coinciding, for example, with the aforementioned first flow region, wherein the second flow region can be arranged, for example, outside the outer swirl chamber and, for example, inside the combustion chamber. It is furthermore conceivable for the aforementioned first flow region to be arranged outside the outer swirl chamber. In other words, it is conceivable that the second part of the air flows out of the outer swirl chamber in a swirling manner and / or flows into the combustion chamber in a swirling manner, so that it is preferably provided that the second part of the air has its swirling flow at least in the combustion chamber.The outer swirl chamber has, in particular precisely, a second outflow opening through which the second part of the air flowing through the outer swirl chamber and the first part of the air flowing through the inner swirl chamber and the first outflow opening, and preferably also the fuel flowing through the first outflow opening, and for example arranged downstream of the first outflow opening in the direction of flow of the parts of the air and in particular of the fuel, via which the second part of the air can be discharged from the outer swirl chamber and the parts of the air and in particular also of the fuel can be introduced into the combustion chamber.In particular, it can thus be provided that the combustion chamber is arranged downstream of the inner swirl chamber and / or downstream of the outer swirl chamber in the flow direction of the respective part of the air flowing through the respective swirl chamber. In particular, the parts of the air and in particular also of the fuel can flow along a second flow direction, in particular in the second flow direction, through the second outflow opening and thus flow into the combustion chamber via the second outflow opening, wherein for example the second flow direction runs parallel to the first flow direction and preferably coincides with the first flow direction. Furthermore, it is preferably provided that the second flow direction runs in the axial direction of the outer swirl chamber, thus coincides with the axial direction of the outer swirl chamber, the radial direction of which runs perpendicular to the axial direction of the outer swirl chamber, so that, for example, the radial direction of the outer swirl chamber coincides with the radial direction of the inner swirl chamber. Thus, it is quite preferably provided that the axial direction of the inner swirl chamber corresponds to the axial direction of the outer swirl chamber or vice versa. The respective axial direction of the respective swirl chamber runs perpendicular to the respective radial direction of the respective swirl chamber, wherein the radial direction of the inner swirl chamber preferably coincides with the radial direction of the outer swirl chamber or vice versa. Since, for example, the second outflow opening is arranged along the respective flow direction, that is to say in the flow direction of the respective part of the air and, for example, downstream of the first outflow opening in the flow direction of the fuel, and since the outer swirl chamber preferably surrounds the first outflow opening, the first outflow opening is arranged, for example, in the outer swirl chamber. In particular, it is conceivable for the outer swirl chamber to end at the second outflow opening, in particular at the end thereof, in particular in the flow direction of the second part of the air flowing through the second outflow opening.In order to generate the swirling flow of the first part of the air, the inner swirl chamber has a first swirl generating device which has first swirl generating elements. By means of the first swirl-generating elements and thus by means of the first swirl-generating device, the first, swirling flow of the first part of the air can be effected. The first swirl-generating elements are assigned in particular to the inner swirl chamber. Furthermore, the outer swirl chamber has a second swirl-generating device which has second swirl-generating elements. The first swirl generating device is also referred to as an inner swirl generating device, and the second swirl generating device is also referred to as an outer swirl generating device. By means of the second swirl-generating elements and thus by means of the second swirl-generating device, the second, swirling flow of the second part of the air can be effected. The second swirl-generating elements are assigned to the outer swirl chamber. In particular, the respective swirl-generating element can be a guide blade, by means of which, for example, the respective part, that is to say the respective air forming the respective part, can be deflected or is deflected at least or exactly once, in particular by at least or exactly 70 degrees, in particular by at least substantially 90 degrees, and very particularly, for example, by 70 degrees to 90 degrees. In particular, the respective swirling flow is understood to mean a flow which extends in a swirling manner, that is to say at least substantially helically or helically, about the respective axial direction of the respective swirl chamber or of the respective outflow opening. In particular, the respective axial direction of the respective outflow opening runs perpendicular to a plane in which the respective outflow opening runs. In this case, for example, the respective axial direction of the respective outflow opening coincides with the respective axial direction of the respective swirl chamber. The respective outflow opening is also referred to as a respective nozzle, for example, whose cross section through which the respective part of the air can flow narrows along the respective flow direction. Thus, for example, the second outflow opening is also referred to as an outer nozzle or second nozzle, wherein, for example, the first outflow opening is also referred to as an inner nozzle or first nozzle.By effecting the respective swirling flow, the air can be mixed with the preferably liquid fuel particularly advantageously, in particular via an even only small mixing path, in particular in the combustion chamber, so that a particularly advantageous mixture treatment can be realized, that is to say the mixture can be formed particularly advantageously. In particular, the fuel, in particular in the inner swirl chamber, can first be mixed particularly well with the first part of the air, in particular on account of the swirling flow of the first part of the air, in particular in the inner swirl chamber. In addition, the fuel and, for example, also the first part of the air already mixed with the fuel can be mixed particularly advantageously with the second part of the air, in particular in the outer swirl chamber and / or in the combustion chamber, since the second part of the air also has an advantageous swirling flow. Overall, due to the swirling flows, the parts of the air and the fuel can be mixed with one another in a particularly advantageous manner, so that a particularly advantageous mixture preparation can be produced.In order to be able to realize a particularly simple and thus time- and cost-effectively performable production of the burner, i.e. in particular in order to be able to assemble the burner particularly simply and thus particularly time- and cost-effectively, it is provided according to the invention that the swirl generating devices are formed integrally with one another, i.e. are formed from a single piece. In other words, the swirl generating devices are formed by a one-piece and thus one-piece swirl generator, thus formed by a single piece and thus integrally produced, which is thus formed as a one-piece, that is to say one-piece and thus formed by a single piece and thus integrally produced monoblock.The second swirl-generating elements directly and partially delimit swirl channels of the second swirl-generating device through which the second part of the air can flow, also referred to as second swirl channels. This means that the second swirl channels are partially and directly delimited by the second swirl generating elements. If the swirl channels are mentioned above and below, this should be understood to mean the second swirl channels of the second swirl generating device, unless otherwise stated. In particular, it is provided that the first swirl-generating device has first swirl channels through which the first part of the air can flow, wherein the first swirl channels are at least partially and in the process directly delimited by the first swirl-generating elements of the first swirl-generating device. Thus, the first swirling flow of the first part of the air can be effected by means of the first swirl channels and by means of the first swirl-generating elements, and the second swirling flow of the second part of the air can be effected by means of the second swirl-generating elements and by means of the second swirl channels. In particular, it is possible for the first swirl channels and the first swirl generating elements to be arranged in succession and in particular spaced apart from one another in the circumferential direction of the inner swirl chamber running around the axial direction of the inner swirl chamber. It is furthermore conceivable for the second swirl-generating elements and the second swirl channels to be arranged in succession and in particular spaced apart from one another in the circumferential direction of the outer swirl chamber running around the axial direction of the outer swirl chamber. In particular, it is provided that the first swirl generating elements and the first swirl channels are arranged alternately in succession in the circumferential direction of the inner swirl chamber. It is furthermore conceivable that in the circumferential direction of the outer swirl chamber the second swirl generating elements and the second swirl channels alternately on one another. In particular, it is provided that the first swirl channels and the first swirl generating elements are arranged uniformly distributed in the circumferential direction of the inner swirl chamber.By means of the first swirl-generating elements, the air or the first part of the air can advantageously be guided, deflected or deflected in such a way that the first swirling flow of the first part of the air can be effected, that is to say is effected. It is furthermore conceivable that the air or the second part of the air can be guided or deflected or deflected by means of the second swirl-generating elements in such a way that the second swirling flow of the second part of the air can be effected, that is to say is effected. It is preferably provided that the swirl generating elements of the respective swirl generating device and the swirl channels of the respective swirl generating device are arranged in succession and / or spaced apart from one another in the circumferential direction of the respective swirl chamber running around the respective axial direction of the respective swirl chamber. For example, the at least one first partial region of the inner swirl chamber is arranged downstream of the first swirl generating device in the flow direction of the first part of the air flowing through the inner swirl chamber. It is furthermore conceivable for the at least one second subregion of the outer swirl chamber to be arranged downstream of the second swirl generating device in the flow direction of the second part of the air flowing through the outer swirl chamber.In order to be able to produce, in particular assemble, the burner particularly easily and thus in a time- and cost-effective manner, it is additionally provided in the invention that the second swirl channels of the second swirl generating device, through which the second part of the air can flow, are also partially and at the same time directly delimited by a first chamber element, which is designed as a solid body and is preferably intrinsically rigid, that is to say dimensionally stable and directly delimits at least one subregion of the combustion chamber, which is also referred to as chamber region. In particular, the first chamber element has a lateral surface on the inner circumference, by which at least the first chamber region of the combustion chamber is directly delimited. If the term "subregion" is used below, this is to be understood as meaning, unless otherwise stated, the first chamber region of the combustion chamber. In particular, it is provided that the inner circumferential lateral surface of the first chamber element is concavely arched.The invention is based in particular on the following findings and considerations: in principle, it would be conceivable to form the swirl-generating devices separately from one another, such that the first swirl-generating device is formed by a first part and the second swirl-generating device is formed by a second part formed separately from the first part. However, in a method for producing the burner, these parts would then have to be positioned exactly relative to one another and relative to the burner, in particular to the first chamber element, in particular in order to ensure advantageous mixture preparation. In other words, for example, the first chamber element is at least one component of the burner. It would be conceivable to connect the first swirl generating device and the second swirl generating device to one another by means of two pins and to position them relative to one another. An exact positioning of the parts in the direction of rotation, i.e. in the circumferential direction of the respective swirl chamber, may not be necessary, in particular because, for example, the respective part or the respective swirl chamber may be configured rotationally symmetrically, in particular with respect to the respective axial direction of the respective swirl chamber. After the parts have been connected to one another and positioned relative to one another, for example, the parts or a structural unit formed by the parts connected to one another and positioned relative to one another are inserted into a receiving opening of the first chamber element and fixed, for example, from above by a housing of the introduction element also referred to as an injector housing. However, this process is very expensive. Dowel holes for the dowel pins result in a double fit, which can only be managed by very precise machining. Assembly of the dowel pins and the parts is thus time-consuming and expensive.The aforementioned problems and disadvantages can now be avoided by the invention. The number of parts of the burner can be kept particularly small and excessively complex machining can be avoided. Since the swirl generating devices are formed integrally with one another and are thus formed by the aforementioned swirl generator, it is not necessary to mount the aforementioned parts, but only the swirl generator can be produced. For example, the swirl generator is produced by an in particular exact primary molding process such as precision casting or cold extrusion. The use of dowel pins can be completely dispensed with. Particularly accurate machining of the burner housing, in particular for receiving the swirl generator, can be advantageous, but in the invention produces not only a fit for the swirl generator but also simultaneously an advantageous shape of an inner surface which, for example in the completely produced state of the burner, can at least partially and at the same time directly surround the outer swirl chamber and thus limit it.In one embodiment of the invention, the second outflow opening is continuous in a passage direction and the parts of the air and preferably also the fuel can flow through it in the passage direction. Thus, for example, the direction of passage coincides with the aforementioned, second flow direction, in which the parts of the air and preferably also the fuel flow through the second outflow opening and can thus flow into the combustion chamber via the second outflow opening.In order to realize a particularly simple and thus time-efficient and cost-effective production of the burner, it has proven particularly advantageous if the second swirl channels of the second swirl generating device are directly delimited in the direction of passage by the first chamber element. The direction of passage thus extends in the axial direction of the outer swirl chamber and thus of the inner swirl chamber, so that it is preferably provided that the second swirl channels are directly delimited by the first chamber element in the axial direction of the respective swirl chamber. In this way, in particular the swirl generator forming the swirl generating devices can be assembled in a time- and cost-effective manner.A further embodiment is distinguished in that the first chamber element at least partially circumferentially delimits at least the partial region of the combustion chamber, that is to say at least the chamber region, in the circumferential direction of the combustion chamber running around the passage direction, and thereby directly delimits it. In particular, it is provided that the aforementioned inner-circumferential surface of the first chamber element at least partially circumferentially delimits at least the partial region of the combustion chamber in the circumferential direction of the combustion chamber extending around the passage direction and thereby directly delimits it. Thus, for example, the circumferential direction of the combustion chamber coincides with the circumferential direction of the respective swirl chamber. This allows a particularly simple production of the burner to be realized.In order to keep the number of parts of the burner particularly small and thus to be able to produce a particularly time-efficient and cost-effective production of the burner, it is provided in a further embodiment of the invention that the first chamber element, in particular the inner-circumferential surface of the first chamber element, completely circumferentially delimits at least the partial region of the combustion chamber, that is to say the chamber region, in the circumferential direction of the combustion chamber running around the passage direction and thereby directly delimits it.In order to keep the number of parts of the burner within a particularly small scope and thus to be able to realize a particularly simple production of the burner, it is provided in a further embodiment of the invention that the first chamber element, in particular the inner-circumferential surface of the first chamber element, at least partially circumferentially delimits and thereby directly delimits at least one length region of the outer swirl chamber in the circumferential direction of the outer swirl chamber running around the passage direction.A further embodiment is distinguished in that the first chamber element has a collar which extends, for example, in the circumferential direction of the combustion chamber running around the passage direction, completely circumferentially and thus completely closed. The collar protrudes in a direction opposite to the direction of passage from a wall region of the first chamber element. The wall region of the first chamber element runs, for example, in a plane which runs perpendicular to the passage direction and thus preferably perpendicular to the respective axial direction of the respective swirl chamber. It is provided here that the second swirl-generating elements engage around the collar. This is to be understood in particular as meaning that the second swirl-generating elements are arranged in such a way that the second swirl-generating elements surround the collar in the circumferential direction of the outer swirl chamber, and are therefore arranged so as to be surrounded. As a result, the collar and the second swirl-generating elements can be used as positioning elements, by means of which the swirl generator and thus the swirl-generating devices can be positioned easily and exactly relative to the first chamber element. Additional, separate positioning elements can thus be avoided, so that the number of parts can be kept particularly small and a particularly simple, time-effective and cost-effective production of the burner can be realized.In order to be able to position the swirl generator, which forms the swirl generating device and is formed from a single piece, relative to the first chamber element in a particularly simple, time-effective and cost-effective manner, it is provided in a further embodiment of the invention that at least one of the second swirl generating elements is supported directly on the collar in a support direction running perpendicular to the passage direction and in particular pointing towards the inner swirl chamber.Finally, it has been shown to be particularly advantageous if the swirl channels are directly delimited in the direction of passage by the mentioned wall region of the first chamber element. As a result, for example, the swirl generator can be positioned particularly easily and thus in a time- and cost-effective manner, for example by the swirl generator being moved relative to the first chamber element in the axial direction of the respective swirl chamber, in particular until the second swirl generating elements come into direct support insert with the wall region as viewed in the axial direction of the respective swirl chamber and thus, as viewed along the passage direction. This makes it possible to ensure simple positioning of the swirl generator relative to the first chamber element.In order to keep the number of parts particularly small and thus to be able to realize a particularly simple production of the burner, it is provided in a further embodiment of the invention that the second outflow opening is completely circumferential along its circumferential direction running around the passage direction and is in this case directly delimited by the first chamber element and in particular by the collar.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 sectional view of a section of an exhaust tract of an internal combustion engine of a motor vehicle having a burner; FIG. 2 is a schematic side view of a one-piece swirl generator of the burner forming a first swirl generating device and a second swirl generating device; FIG. 3 is a schematic longitudinal sectional view of the swirl generator; FIG. 4 is a schematic perspective view of the swirl generator; FIG. 5 shows a schematic and sectional perspective view of a first chamber element of the burner in detail; FIG. 6 shows a schematic sectional view of the burner in detail; and FIG. 7 shows a detail of a further schematic sectional view of the burner.In the figures, identical or functionally identical elements are provided with identical reference symbols.FIG. 1 shows a schematic sectional view of a portion of an exhaust tract 10, also referred to as an exhaust system, of a motor vehicle preferably embodied as a motor vehicle, in particular as a passenger car, which is also referred to simply as a vehicle. The motor vehicle has a drive device, not shown in detail in the figures, by means of which the motor vehicle can be driven. In addition, the motor vehicle has the exhaust tract 10. The drive device has an internal combustion engine, also referred to as an internal combustion engine or internal combustion engine, which has an engine block, also referred to as an engine housing. Furthermore, the internal combustion engine has at least one or more cylinders which are formed or bounded by the engine block, in particular directly. During a fired operation of the internal combustion engine, respective combustion processes take place in the cylinders, resulting in an exhaust gas of the internal combustion engine. For this purpose, within a respective working cycle of the internal combustion engine, an in particular liquid fuel is introduced into the respective cylinder, in particular directly injected. The internal combustion engine, the exhaust gas of which is also referred to as engine exhaust gas, can be designed as a diesel engine, so that the fuel is preferably a diesel fuel. In this case, a tank referred to as a fuel tank is also provided, in which the fuel can be received or is received. A respective injector is assigned to the respective cylinder, for example, by means of which the fuel can be introduced, in particular directly injected, into the respective cylinder. For example, the fuel is conveyed from the tank by means of a low-pressure pump to a high-pressure pump, by means of which the fuel is conveyed to the injectors or to a fuel distribution element common to the injectors and also referred to as a rail or common rail. The injectors can be supplied with the fuel from the fuel distribution element common to the injectors by means of the fuel distribution element and can introduce, in particular directly inject, the fuel from the fuel distribution element into the respective cylinder.The drive device comprises, for example, an intake tract through which fresh air can flow, by means of which the fresh air flowing through the intake tract is guided to and into the cylinders. The fresh air forms with the fuel a fuel-air mixture, which comprises the fresh air and the fuel and is ignited within the respective working cycle in the respective cylinder and is thereby burned. Specifically, the air-fuel mixture is ignited by self-ignition. The ignition and combustion of the fuel-air mixture results in the exhaust gas of the internal combustion engine, the exhaust gas of which is also referred to as engine exhaust gas or engine exhaust gas.The drive device has, for example, the exhaust tract 10 through which the exhaust gas can flow from the cylinder. The internal combustion engine or the drive device also comprises, for example, an exhaust gas turbocharger which has a compressor arranged in the exhaust tract and a turbine arranged in the exhaust tract. The exhaust gas can flow out of the cylinders, flow into the turbine and then flow through the exhaust tract 10. The turbine can be driven by the exhaust gas flowing through the exhaust tract 10. The compressor can be driven by the turbine, in particular via a shaft of the exhaust gas turbocharger. By driving the compressor, the fresh air flowing through the intake tract can be compressed by means of the compressor.For example, a plurality of components are arranged in the exhaust tract 10, which components are designed as respective exhaust gas aftertreatment devices or exhaust gas aftertreatment elements, that is to say as exhaust gas aftertreatment components for aftertreatment of the exhaust gas. In the flow direction of the exhaust gas of the internal combustion engine flowing through the exhaust tract 10, the components are arranged in succession and are thus connected in series or in series with one another. A first of the components is, for example, an oxidation catalyst, in particular a diesel oxidation catalyst (DOC). Furthermore, the first component may be a nitrogen oxide storage catalyst (SOC), or the first component may comprise such a nitrogen oxide storage catalyst. A second of the components may be an SCR catalyst, which is also referred to simply as SCR. A third of the components can be a particle filter, in particular a diesel particle filter (DPF). A fourth of the components can be, for example, a second SCR catalyst and / or an ammonia barrier catalyst (ASC). In other words, for example, the fourth component can have a second SCR catalyst and / or an ammonia trap catalyst.The drive device can comprise a metering device, by means of which an in particular liquid reducing agent can be introduced into the exhaust tract 10 and, in the process, for example into the exhaust gas flowing through the exhaust tract 10 at a first introduction point. The reducing agent is preferably an aqueous urea solution which can provide ammonia which, in the case of a selective catalytic reduction, can react with nitrogen oxides possibly present in the exhaust gas to form water and nitrogen. This selective catalytic reduction can be catalytically effected and / or supported by the SCR catalyst. In the flow direction of the exhaust gas flowing through the exhaust tract 10, the first introduction point is arranged, for example, upstream of the second component and downstream of the first component, wherein the second component is arranged downstream of the first component. For example, the fourth component is arranged downstream of the third component, wherein the third component is arranged downstream of the second component and upstream of the fourth component. For example, the exhaust tract has a mixing chamber in which the reducing agent introduced into the exhaust gas at the first introduction point can advantageously be mixed with the exhaust gas, wherein for example the mixing chamber can be arranged upstream of the second component and for example downstream of the first component.The exhaust tract 10 and thus the drive device and the motor vehicle also comprise a burner 12, by means of which, as will be explained in more detail below, at least one of the components, for example the second component and / or the third component and / or the fourth component, can be heated and / or kept warm quickly and efficiently, wherein the at least one component is arranged in particular downstream of the burner in the exhaust tract 10. The burner 12 can combust a mixture, in particular forming a flame, resulting in a burner exhaust gas of the burner 12, which provides the burner exhaust gas. For example, the burner exhaust gas or the flame can be introduced into the exhaust tract 10, i.e. into an exhaust gas duct 14 of the exhaust tract 10 through which the exhaust gas can flow, at a second introduction point E 2. This means that the burner 12 is arranged at the second introduction point E 2. For example, the second introduction point E 2 is arranged upstream of the second component, upstream of the third component and upstream of the fourth component and downstream of the first component. Alternatively, it is conceivable for the burner 12 or the second introduction point E 2 to be arranged upstream of the first component and in particular downstream of the turbine. The aforementioned mixture to be burned in the burner 12 or by means of the burner 12 comprises air and a preferably liquid fuel. For example, in the embodiment shown in the figures, the fuel mentioned above is used as the fuel. Alternatively or additionally, at least a portion of the air that is supplied to the burner 12 and used to form the mixture may originate from the intake tract, for example. For example, a fuel supply path is provided, which is or can be connected fluidically to the burner 12 on the one hand and fluidically to a fuel line on the other hand. The fuel line can be flown through by the fuel from the tank to the injectors or to the fuel distribution element. In particular, the fuel supply path is fluidically connected to the fuel line at a first connection point, wherein the first connection point is arranged downstream of the low-pressure pump and upstream of the high-pressure pump in the flow direction of the fuel flowing from the tank to the fuel distribution element or to the respective injector. At the first connection point, at least a portion of the fuel, in particular liquid fuel, flowing through the fuel line can be branched off from the fuel line and introduced into the fuel supply path. The fuel introduced into the fuel supply path may flow through the fuel supply path and is conducted as the fuel by means of the fuel supply path to and in particular into the burner 12. In this case, for example, a first valve element is arranged in the fuel supply path, by means of which valve element an amount of the fuel flowing through the fuel supply path and thus to be supplied to the burner 12 can be adjusted. In this case, for example, an electronic computing device, also referred to as a control unit, is provided, by means of which the first valve element can be actuated, so that the quantity of fuel flowing through the fuel supply path and to be supplied to the burner 12 can be adjusted, in particular regulated, by means of the control unit via the first valve element.Furthermore, for example, an air supply path is provided, via which or by means of which the burner 12 can be supplied or is supplied with the air for forming the mixture, which is also referred to as burner mixture. This means that the air from which the mixture is formed can flow through the air supply path. In this case, an electrically driven pump, also referred to as an air pump, is arranged, for example, in the air supply path, by means of which pump the air can be conveyed through the air supply path and thus conveyed to the burner 12.For example, the low-pressure pump, also referred to as a low-pressure fuel pump, is used as a fuel pump, by means of which the fuel is conveyed through the fuel supply path and is thus conveyed toward the burner 12. The air supply path is, for example, fluidically connected to the intake tract at a second connection point. Thus, for example, at the second connection point, at least a portion of the fresh air flowing through the intake tract can be branched off from the intake tract and introduced into the air supply path. The fresh air introduced into the air supply path can flow through the air supply path as the air for forming the mixture and is conducted by means of the air supply path to and in particular into the burner 12. In this case, for example, a second valve element is arranged in the air supply path, by means of which valve element an amount of the air, which is used to form the mixture and flows through the air supply path and thus through the burner 12, can be adjusted. In this case, for example, the control unit is designed to actuate the second valve element, with the result that, for example, the quantity of air which is used to form the mixture and which flows through the air supply path and is thus to be supplied to the burner 12 can be adjusted, in particular regulated, by means of the control unit via the second valve element.As can be seen from FIG. 1, the burner 12 has a combustion chamber 16 in which the air, which is supplied to the burner 12 and is also referred to as burner air and from which the mixture is formed, and the mixture comprising liquid fuel supplied to the burner 12 are to be ignited and thereby burnt, that is to say is ignited and thereby burnt during operation of the burner 12. For this purpose, for example, an ignition device 18, which is in particular electrically operable and is in particular embodied as a spark plug or glow plug or glow pin and is, for example, a component of the burner 12, is provided. By means of the ignition device 18, at least one ignition spark can be generated, in particular using electrical energy or electrical current in the combustion chamber 16. The mixture in the combustion chamber 16 is ignited by means of the ignition spark and is subsequently burned, in particular with provision of the burner exhaust gas and / or with provision of the mentioned flame. By means of the burner exhaust gas or by means of the flame, for example, the exhaust gas flowing through the exhaust tract 10, that is to say the exhaust gas flowing through the exhaust gas duct 14, can be heated and / or kept warm quickly and efficiently, with the result that, by means of the heated and / or kept warm exhaust gas (engine exhaust gas) which flows through, for example, the second component, the third component and the fourth component, for example, at least the second component can be heated and / or kept warm quickly and efficiently.The burner 12 has a first, inner swirl chamber 20, through which a first part of the air, also referred to as burner air, which is supplied to the burner 12 and used for forming the mixture, can flow or is flowed and brings about a first swirling flow of the first part of the air, and is therefore designed for bringing about a first swirling flow of the first part of the air. This is to be understood in particular as meaning that the first part of the air flows through at least a first partial region of the inner swirl chamber 20 in a swirl-like manner and / or flows out of the inner swirl chamber 20 in a swirl-like manner and / or flows into and thus in the combustion chamber 16 in a swirl-like manner. The inner swirl chamber 20 has, in particular precisely, a first outflow opening 22, through which the first part of the air can flow in a first passage direction of the outflow opening 22 and thus in a first flow direction coinciding with the first passage direction, or through which the air can flow during the aforementioned operation. The first direction of passage and thus the first direction of flow are illustrated by an arrow 23 in particular in FIGS. 1 and 3. The first part of the air can be discharged from the inner swirl chamber 20 via the first outflow opening 22. This means that the first part of the air can flow out of the inner swirl chamber 20 via the first outflow opening 22.Furthermore, the burner 12 comprises an introduction element 24, in the present case in the form of an injection element, through which the liquid fuel which is supplied to the burner 12 can flow. The introduction element 24 preferably has an outlet opening, in particular at least two outlet openings, also referred to as injection openings, through which the fuel supplied to the introduction element 24 can flow, wherein the fuel flowing through the respective outlet opening flows out of the introduction element 24, in particular as a whole. The fuel can flow through the respective outlet opening, for example, along a passage direction, so that the fuel flowing through the introduction element 24 can be injected or can emerge from the introduction element 24 via the respective outlet opening and can be injected, in particular directly, into the inner swirl chamber 20 and can thereby be introduced. Preferably, the respective outlet openings can be provided slightly inclined to the axial direction of the combustion chamber 16, the axial direction of which coincides with the aforementioned first passage direction 23, for example. Furthermore, for example, the axial direction of swirl chamber 20, the radial direction of which runs perpendicular to the axial direction of inner swirl chamber 20, coincides with a burner longitudinal axis of burner 12, which extends, for example, along its burner longitudinal axis in an elongate manner. In particular, for example, the inner swirl chamber 20 and / or the combustion chamber 16 can be configured rotationally symmetrically with respect to the burner longitudinal axis. The introduction element 24 is designed in particular to eject the fuel from the outlet openings in a clocked manner and thus to inject it in a clocked manner into the inner swirl chamber 20, in particular directly, in particular to eject it onto a first surface 26, which is designed as an inner-circumferential lateral surface and directly delimits the inner swirl chamber 20, in particular in the radial direction of the inner swirl chamber 20 on the outside. In other words, the inner swirl chamber 20 is directly delimited at least partially, in particular at least predominantly and thus at least to an extent of more than half or else completely, by the first surface 26, which in the present case is an inner-circumferential-side lateral surface.The respective further direction of passage of the respective outlet opening coincides with a respective further direction of flow along which or into which the fuel can flow through the respective outlet opening and thus can flow out of the introduction element 24. The fuel can be injected from the introduction element 24 via the respective outlet opening, in particular forming a respective fuel jet, and can thereby be injected in particular directly into the inner swirl chamber 20. In addition, for example, the introduction element 24 has a longitudinal direction or longitudinal extent or longitudinal extent direction which runs parallel to the first passage direction 23 and thus parallel to the first flow direction and parallel to the axial direction of the inner swirl chamber 20, in particular coincides with the first passage direction 23 and thus with the first flow direction and thus in particular coincides with the axial direction of the inner swirl chamber 20. For example, the respective further passage direction runs perpendicular or, in the present case, obliquely to the first passage direction 23 and thus to the first flow direction and to the axial direction of the inner swirl chamber 20 and the first outflow opening 22.The inner swirl chamber 20 is formed or bounded at least partially, in particular at least predominantly and thus at least to a greater extent than half or else completely, by a swirl generator 28 of the burner 12, such that, for example, the swirl generator 28 also forms or bounds the first outflow opening 22, in particular directly. Thus, for example, the swirl generator 28 forms the first surface 26. The inner swirl chamber 20 is also referred to as a prefilmer.The burner 12 furthermore has an outer swirl chamber 30, which surrounds at least one length region L 1 and in the present case also the first outflow opening 22 in the circumferential direction of the inner swirl chamber 20, in particular in a completely encircling manner, running around the axial direction of the inner swirl chamber 20. In this case, the swirl generator 28 has, for example, a separating wall 32 which is arranged between the swirl chambers 20 and 30 in the radial direction of the inner swirl chamber 20 and therefore in the radial direction of the outer swirl chamber 30, the radial direction of which coincides with the radial direction of the inner swirl chamber 20. Thereby, the swirl chambers 20 and 30, whose axial directions are coincident with each other, are separated from each other in the radial direction of the swirl chambers 20 and 30 by the partition wall 32. The axial direction of the inner swirl chamber 20 coincides with the axial direction of the inner swirl chamber 20 whose radial direction is perpendicular to the axial direction of the outer swirl chamber 30, and the radial direction of the inner swirl chamber 20 coincides with the radial direction of the outer swirl chamber 30. A second part of the burner air, which is supplied to the burner 12 and used for forming the mixture, can flow through the outer, second swirl chamber 30 and is designed to bring about a second swirling flow of the second part of the air. This means that the second part of the air flows through the outer swirl chamber 30 in a swirling manner and / or flows out of the swirl chamber 30 in a swirling manner and / or flows into and thus in the combustion chamber 16 in a swirling manner. In particular, it is preferably provided that the second part of the air flows through at least one second partial region of the outer swirl chamber 30 in a swirl-like manner and / or flows out of the outer swirl chamber 30 in a swirl-like manner and / or flows into and thus in the combustion chamber 16 in a swirl-like manner. The air is supplied to the burner 12 from, for example, the above-mentioned air pump via a port 33.The outer, second swirl chamber 30 has, in particular precisely, a second outflow opening 34, through which the second part of the air flowing through the outer swirl chamber 30 can flow, in particular in a second flow direction, the second flow direction of which, coinciding with the second flow direction, through which the second part of the air flowing through the outer swirl chamber 30 can flow, the outflow opening 34 in the present case coincides with the axial direction of the outer swirl chamber 30 and thus with the axial direction of the inner swirl chamber 20. The second direction of passage coincides with the third direction of flow, along which or into which the second part of the air flowing through the outer swirl chamber 30 flows through or can flow through the outflow opening 34. This means in particular that the first passage direction 23 coincides with the second passage direction and the first flow direction coincides with the second flow direction, so that in the present case the first flow direction, the second flow direction, the first passage direction 23 and the second passage direction coincide with the axial direction of the inner swirl chamber 20 and with the axial direction of the outer swirl chamber 30. Thus, the first direction of passage, the first direction of flow, the second direction of passage, and the second direction of flow are illustrated by arrow 23. In the flow direction of the air flowing through the swirl chambers 20 and 30, in particular the outflow openings 22 and 34, the second outflow opening 34 is arranged downstream of the first outflow opening 22 and in this case is arranged or connected in particular in series or in series with the first outflow opening 22, such that the second outflow opening 34 can be flowed through by the second part of the air, by the first part of the air and by the fuel. In particular, the first part of the air is already mixed with the fuel in the inner swirl chamber 20, in particular due to the swirling first flow, in particular with the formation of a submixture. The partial mixture can flow through the outflow opening 22 and thus flow out of the inner swirl chamber 20 and then flow through the second outflow opening 34 and is mixed with the second part of the air, in particular on account of the advantageous, second swirling flow, as a result of which the mixture is processed particularly advantageously, and therefore the partial mixture is mixed particularly advantageously with the second part of the air, as a result of which the mixture is formed.It can be seen that the outer swirl chamber 30 is bounded at least partially, in particular at least predominantly and thus at least to more than half or even completely, inward in the radial direction of the respective swirl chamber 20, 30 by the swirl generator 28, in particular by the partition 32. In this case, in particular the inner swirl chamber 20 is bounded towards the outside in the radial direction of the respective swirl chamber 20, 30, at least partially, in particular at least predominantly or completely, by the swirl generator 28, in particular by the partition 32. In the radial direction of the respective swirl chamber 20, 30 toward the outside, the outer swirl chamber 30 is at least partially, in particular at least predominantly and thus at least to more than half or even completely, delimited by a first chamber element 36 of the burner 12, which is explained in more detail below. In particular, the inner swirl chamber 20 is bounded towards the outside in the radial direction of the swirl chamber 20, 30 at least partially by the first surface 26, in particular directly. The outer swirl chamber 30 is bounded towards the outside in the radial direction of the respective swirl chamber 20, 30 at least partially by a second surface 38 which is embodied in the present case as an inner circumferential lateral surface, in particular directly, wherein the second surface 38 is formed in particular by the first chamber element 36.In the exemplary embodiment shown in the figures, it is provided that the first chamber element 36 and the swirl generator 28 are components which are formed separately from one another and are connected to one another at least indirectly. In this case, the swirl generator 28 is arranged at least partially, in particular at least predominantly and thus at least to an extent of more than half or else completely, in the first chamber element 36. The second outflow opening 34 is bounded or formed in a completely encircling manner by the first chamber element 36 along its circumferential direction running around the axial direction of the respective swirl chamber 20, 30, in particular towards the outside in the radial direction of the respective swirl chamber 20, 30.It can be seen from FIG. 1 that the combustion chamber 16 is bounded at least partially, in particular at least predominantly and thus at least to an extent of more than half or completely, by a second chamber element 40 of the burner 12, which is designed as a solid body and is self-rigid and therefore dimensionally stable, in particular directly. In particular, the second chamber element 40 has a third surface 42 which is formed as an inner circumferential surface and by which the combustion chamber 16 is at least partially directly delimited, in particular in the radial direction of the respective swirl chamber 20, 30 towards the outside. In other words, for example, the combustion chamber 16 is at least partially, in particular at least predominantly or else completely, outwardly in the radial direction of the respective swirl chamber 20, 30, and is in this case preferably directly delimited by the third surface 42.The second chamber element 40 has a wall 44 which is spaced apart from the outflow openings 22 and 34 in the axial direction of the respective swirl chamber 20, 30 and thus in the first or second flow direction, wherein the combustion chamber 16 is bounded, in particular directly bounded, by the wall 44, in particular by a fourth surface 46 of the wall 44 and thus of the second chamber element 40, in the axial direction of the respective swirl chamber 20, 30 and thereby in the first or second flow direction, thus in a boundary direction running parallel to the axial direction of the respective swirl chamber 20, 30 and pointing away from the swirl chambers 20 and 30. It is conceivable that the surfaces 42 and 46 are components of an inner circumferential-side overall surface of the second chamber element 40. The wall 44 is penetrated, for example, by a plurality of through-openings 48 which completely penetrate the wall 44. In the exemplary embodiment shown in the figures, the through-openings 48 are arranged in succession and at a distance from one another in the circumferential direction running around the respective axial direction of the respective swirl chamber 20, 30 and are arranged in particular uniformly distributed. Furthermore, the through openings 48 are circular and thus are formed as circles, for example, whose centers lie on a further circle whose center lies on the axial direction of the respective swirl chamber 20, 30. In particular, the outer swirl chamber 30 is configured rotationally symmetrically with respect to its axial direction and thus in particular with respect to the burner longitudinal axis. The burner exhaust gas from the combustion chamber 16 can flow through the passage openings 48 and thus flow out of the combustion chamber 16 via the passage openings 48 and in particular flow into the exhaust tract 10, that is to say into the exhaust gas duct 14, at the second introduction point E 2.It can be seen particularly well from FIGS. 2 and 4 that the first inner swirl chamber 20 has a first swirl generating device 50, by means of which the first swirling flow of the first part of the air can be effected or is effected. The first swirl-generating device 50 has first swirl-generating elements 52. For example, the first swirl-generating elements 52 are designed as first guide vanes. It can be seen from FIG. 7, for example, that the swirl generator 28 is inserted into the first chamber element 36, in particular in the axial direction of the respective swirl chamber 20, 30. The first swirl-generating elements 52 are assigned to the first inner swirl chamber 20. By means of the first swirl-generating elements 52, the first swirling flow of the first part of the air can be effected. The second outer swirl chamber 30 has a second swirl generating device 54, by means of which the second swirling flow of the second part of the air can be effected. For this purpose, the second swirl-generating device 54 has second swirl-generating elements 56. For example, the second swirl-generating elements 56 are designed as second guide vanes. The second swirl-generating elements 56 are assigned to the outer swirl chamber 30. The first swirling flow of the first part of the air can be or is generated by means of the first swirl-generating elements 52, and the second swirling flow of the second part of the air can be or is generated by means of the second swirl-generating elements 56. The swirl-generating elements 52, 56 are arranged in succession and in particular at a distance from one another in the circumferential direction of the respective swirl chamber 20, 30 running around the axial direction of the respective swirl chamber 20, 30, in such a way that respective swirl channels 58, 60 of the respective swirl-generating device 50, 54 are arranged between the respective swirl-generating elements 52, 56 in the circumferential direction of the respective swirl chamber 20, 30. The swirl channels 58 are also referred to as first swirl channels and are first swirl channels of the first swirl generating device 50, and the swirl channels 60 are also referred to as second swirl channels and are swirl channels of the second swirl generating device 54 It can be seen that the swirl generating elements 52 and the swirl channels 58 are arranged alternately one after the other in the circumferential direction of the respective swirl chamber 20, 30, wherein the swirl generating elements 56 and the swirl channels 60 are arranged alternately one after the other in the circumferential direction of the respective swirl chamber 20, 30. The swirl channels 58, 60 are thus arranged successively and spaced apart from one another in the circumferential direction of the respective swirl chamber 20, 30 and in the present case separated from one another in such a way that a respective one of the swirl generating elements 52, 56 of the respective swirl generating device 50, 54 is arranged in the circumferential direction of the respective swirl chamber 20, 30 between in each case two adjacent swirl channels 58, 60, in particular exactly. It can be seen that the respective swirl channel 58, 60 is directly bounded on both sides in the circumferential direction of the respective swirl chamber 20, 30 by two adjacent swirl generating elements 52, 56. In other words, for example, the respective swirl channel 58 is directly delimited on both sides in the circumferential direction of the respective swirl chamber 20, 30 by respective fifth surfaces 62, in particular of the component 28. Accordingly, the respective swirl channel 60 is directly bounded on both sides in the circumferential direction of the respective swirl chambers 20, 30 by respective sixth surfaces 64, in particular of the structural element 28. The respective fifth surface 62 is a respective surface of one of the swirl generating elements 52, and the respective sixth surface 64 is a respective surface of a respective one of the swirl generating elements 56.In order to be able to realize a particularly simple and thus time- and cost-effective production of the burner 12, the swirl generating devices 50 and 54 and thus the swirl generating elements 52 and the swirl generating elements 56 are formed integrally with one another, that is to say are formed from a single piece. In the exemplary embodiment shown in the figures, it is provided that the swirl generator 28 forms the partition wall 32 and the swirl generating devices 50 and 54 and thus the swirl generating elements 52 and 56, wherein the swirl generator 28 is formed integrally, that is to say is formed from a single piece. Furthermore, it is provided that the second swirl channels 60 of the second swirl generating device 54 through which the second part of the air can flow are partially delimited by the swirl generator 28, in particular directly in each case, in the circumferential direction of the respective swirl chamber 20, 30 and in a delimiting direction opposite the first flow direction and thus the second flow direction and illustrated by an arrow 66. The delimiting direction coincides with the axial direction of the respective swirl chamber 20, 30 or runs parallel to the respective axial direction of the respective swirl chamber 20, 30. the swirl channels 60 of the second swirl generating device 54 are partially delimited, and in the process, in the first flow direction and thus in the second flow direction by the first chamber element 36 formed separately from the swirl generator 28, as can be seen particularly well from FIG. 6. The first chamber element 36 directly delimits at least a partial region of the combustion chamber 16. The first chamber element 36 directly delimits at least the named partial region of the combustion chamber 16, and the first chamber element 36 partially and directly delimits the swirl channels 60 in such a way that the swirl channels 60 are partially and directly delimited by the first chamber element 36 in the first flow direction and thus in the second flow direction and thus in the axial direction of the respective swirl chamber 20, 30. For example, it is provided that the first chamber element 36 bounds or thereby directly bounds at least the partial region of the combustion chamber 16 in a circumferential direction of the combustion chamber 16, in particular completely, circumferentially in the direction extending around the axial direction of the respective swirl chamber 20, 30 and thus around the second passage direction.It can be seen particularly well from FIG. 7 that the first chamber element 36 at least partially, in particular completely, circumferentially delimits and thereby directly delimits at least the length region L 1 of the outer swirl chamber 30 in the circumferential direction of the outer swirl chamber 30 running around the axial direction of the respective swirl chamber 20, 30 and thus also of the inner swirl chamber 20, in particular in such a way that the second surface 38 of the first chamber element 36, which is embodied in the present case as an inner circumferential surface, at least partially, in particular at least predominantly or completely delimits and thereby directly delimits at least the length region L 1 of the outer swirl chamber 30 in the circumferential direction of the respective swirl chamber 20, 30.It can be seen particularly well from FIGS. 5 and 6 that the first chamber element 36 has a collar 68, which projects from a wall region W of the first chamber element 36 into an air chamber 69 in a direction which is opposite the second passage direction and thus the first passage direction 23 and is illustrated by an arrow 70, which is for example the delimiting direction 66. The air chamber 69 is communicated with the port 33 and is supplied with air from the air pump through the port 33. From the air chamber 69, the air enters the swirl generator 28 via the first swirl generating device 50 and the second swirl generating device 54. The collar 68 has, perpendicular to the second passage direction, a first step S 1 encircling the collar 68 and a second step S 2 encircling the collar 68. The first step S 1 forms a first ring surface R 1 arranged perpendicular to the second passage direction, wherein the first ring surface R 1 is followed by the second step S 2. The second step S 2 forms a second annular surface R 2. The first, planar annular surface R 1 and the second, planar annular surface R 2 are arranged perpendicular to the second passage direction, wherein the first annular surface R 1 has a larger diameter than the second annular surface R 2.In the exemplary embodiment shown in the figures, it is provided that the second swirl-generating elements 56 bear directly against the second annular surface R 2 of the collar 68 in the first passage direction 23 and thus in the second passage direction 70 and are thus supported. In this case, for example, a respective first part T 1 of the respective second swirl-generating element 56 bears directly against the second annular surface R 2 in the first passage direction 23, and for example a respective second part T 2 of the respective second swirl-generating element 56 comprises the second step S 2 in the direction of the first annular surface R 1 in the first passage direction 23. The second part T 2 of the respective second swirl-generating element 56 protrudes from the first part T 1 at the outer edge of the respective second swirl-generating element 56, as viewed in the radial direction. In other words, the respective second part T 2 projects beyond the respective first part T 1 in the first passage direction 23, and therefore, for example, the respective swirl channel 60 is directly delimited in the second passage direction 70 by the second annular surface R 2, respectively. It can be seen particularly well from a combination of FIGS. 4 to 6 that the second swirl-generating elements 56 engage around the collar 68, in particular in such a way that the second parts T 2 engage around the collar 68 at the second step S 2. In this case, at least one of the second swirl-generating elements 56 is preferably supported directly on the collar 68, in particular on the second stage S 2, in a support direction which runs perpendicular to the second passage direction 70 and in particular points from the at least one of the second swirl-generating elements 56 toward the first inner swirl chamber 20, and which coincides with the respective radial direction of the respective swirl chamber 20, 30 or runs parallel to the respective radial direction of the respective swirl chamber 20, 30. As a result, the swirl generator 28 can be positioned easily and precisely relative to the first chamber element 36.It can be seen that the second annular surface R 2 and the second surface 38 delimit a receiving opening 72, into which, for example, the swirl generator 28 with its dividing wall 32 is at least partially inserted, in such a way that the swirl generator 28 is moved in the second passage direction relative to the first chamber element 36. In the completely produced state of the burner 12, the second surface 38 directly delimits the second outer swirl chamber 30 in the radial direction of the respective swirl chamber 20, 30 toward the outside.In the direction illustrated by the arrow 70, as can be seen from FIG. 6, the first swirl channels 58 are each directly bounded by a further component 74 of the burner 12. The further structural element 74 is preferably formed separately from the swirl generator 28 and separately from the first chamber element 36. The further component 74 can be, for example, a housing for the introduction element 24. In the direction illustrated by the arrow 70, the first swirl channels are directly delimited by the structural element 74, wherein, for example, the swirl generator 28, in particular the first swirl generating elements 52, is or are supported at least indirectly, in the present case directly, on the structural element 74 in the direction illustrated by the arrow 70. Thus, for example, the swirl generator 28 is clamped between the structural element 74 and the first chamber element 36 in the axial direction of the respective swirl chamber 20, 30.FIG. 7 shows a variant in which the swirl generator 28 is supported indirectly on the structural element 74 in the direction illustrated by the arrow 70 and in this case via a spring device 76, wherein the spring device 76 is formed separately from the structural element 74, separately from the swirl generator 28 and separately from the first chamber element 36. It is conceivable that the first swirl channels 58 are directly delimited by the spring device 76 at least partially, in particular at least predominantly and thus at least to an extent of more than half or even completely, in the direction illustrated by the arrow 70. The spring device 76 is or comprises, for example, at least or exactly one spring element 78, which is designed as a solid body and thus as a mechanical spring. In the present case, the spring element 78 is designed as a disk spring. Furthermore, for example, the spring device 76 can have an intermediate element 80 which is embodied in the present case as a disk and is embodied separately from the spring element 78 and also separately from the swirl generator 28 and separately from the first chamber element 36. The intermediate element 80 is arranged along the respective axial direction of the respective swirl chamber 20, 30 between the first swirl-generating device 50 and the spring element 78, so that in the present case the swirl generator 28, in particular the first swirl-generating elements 52, is supported on the spring element 78 via the intermediate element 80 in the direction illustrated by the arrow 70. By means of the spring device 76, the swirl generator 28 can be pressed or pressed against the first chamber element 36 in the second passage direction and thus pressed or pressed against a seat. For this purpose, the spring device 76, in particular the spring element 78, is elastically deformed, as a result of which the spring device 76, in particular the spring element 78, provides a spring force by means of which the swirl generator 28 is held in a particularly direct supporting insert with the first chamber element 36, in particular with the wall region W and / or the second annular surface R 2. This makes it possible to ensure a secure fit and thus a secure positioning of the component 28, even if, for example, the introduction element 24, in particular its housing (component 74), in particular viewed along the axial direction of the respective swirl chamber 20, 30, was not moved completely as far as a stop and, in the process, was pressed, for example, into a burner housing of the burner 12 and / or if, for example, if the spring device 76 were not provided, some play for the swirl generator 28, which would result, in particular in the axial direction of the respective swirl chamber 20, 30, between the swirl generator 28 and the component 74 and / or the first chamber element 36, would result due to different thermal expansions. Consequently, relative movements between the components 74 and 36, which are in particular thermally induced, can be compensated for by means of the spring device 76, wherein such relative movements occur as a result of different expansions of the components 74 and 36, which are thermally induced.List of reference characters10 Exhaust tract 12 Burner 14 Exhaust gas duct 16 Combustion chamber 18 Ignition device 20 Inner swirl chamber 22 First outflow opening 23 First passage direction 24 Introduction element 26 First surface 28 Swirl generator 30 Outer swirl chamber 32 Partition wall 33 Connection 34 Second outflow opening 36 First chamber element 38 Second surface 40 Second chamber element 42 Third surface 44 Wall 46 Fourth surface 48 Passage opening 50 First swirl generation device 52 First swirl generation element 54 Second swirl generation device 56 Second swirl generation element 58 First swirl channel 60 Second swirl channel 62 Fifth surface 64 Sixth surface 66 Boundary direction 68 Collar 69 Air chamber 70 Second passage direction 72 Receiving opening 74 Further component 76 Spring device 78 Spring element 80 Intermediate element E 2 Second introduction point L 1 Length region R 1 First annular surface R 2 Second annular surface S 1 First stage S 2 second stage T1 first part T2 second part W wall region

Claims

Burner (12) for an exhaust tract (10) through which exhaust gas from an internal combustion engine of a motor vehicle can flow, having: - a combustion chamber (16) in which a mixture comprising air and a fuel can be ignited and thereby burned; - an inner swirl chamber (20) through which a first part of the air can flow, which has a first swirl-generating device (50) with first swirl-generating elements (52), by means of which a swirling flow of the first part of the air can be effected, and a first outflow opening (22) through which the first part of the air flowing through the inner swirl chamber (20) can flow, via which the first part of the air can be discharged from the inner swirl chamber (20), and - a second part of the air can flow, which surrounds at least one longitudinal region of the inner swirl chamber (20) in the circumferential direction of the inner swirl chamber (20), Outer swirl chamber (30) which has a second swirl-generating device (54) having second swirl-generating elements (56), by means of which a swirling flow of the second part of the air can be effected, and a second outflow opening (34), through which the second part of the air flowing through the outer swirl chamber (30) can flow, and through which the first part of the air flowing through the inner swirl chamber (20) and the first outflow opening (22) can flow, via which the parts of the air can be introduced into the combustion chamber (16); characterized in that: - the swirl-generating devices (50, 54) are formed integrally with one another; - swirl channels (60) of the second swirl-generating device (54), through which the second part of the air can flow, are in each case directly delimited in part by the second swirl-generating elements (56) and in part by a first chamber element (36), which directly delimits at least a partial region of the combustion chamber (16).Burner (12) according to Claim 1, characterized in that the second outflow opening (34) can be flowed through continuously in a passage direction (23) and by the parts of the air can flow through.Burner (12) according to Claim 2, characterized in that the swirl ducts (60) are directly delimited in the direction of passage (23) by the first chamber element (36).Burner (12) according to Claim 2 or 3, characterized in that the first chamber element (36) at least partially bounds and thereby directly bounds the partial region of the combustion chamber (16) in a circumferential direction of the combustion chamber (16) running around the passage direction (23).Burner (12) according to Claim 4, characterized in that the first chamber element (36) completely bounds and thereby directly bounds at least the subregion of the combustion chamber (16) in a circumferential direction of the combustion chamber (16) running around the passage direction (23).Burner (12) according to one of Claims 3 to 5, characterized in that the first chamber element (36) at least partially circumferentially delimits at least one longitudinal region (L1) of the outer swirl chamber (30) in the circumferential direction of the outer swirl chamber (30) running around the passage direction (23), and thereby directly delimits it.Burner (12) according to one of Claims 3 to 6, characterized in that the first chamber element (36) has a collar (68) which projects from a wall region (W) of the first chamber element (36) in a direction (70) opposite the direction of passage (23), the second swirl-generating elements (56) enclosing the collar (68).Burner (12) according to Claim 7, characterized in that at least one of the second swirl-generating elements (56) is supported directly on the collar (68) in a supporting direction running perpendicular to the passage direction (23).Burner (12) according to claim 7 or 8 in its reference back to claim 3 or in its reference back to at least one of claims 4 to 6 in claim 3, characterised in that the swirl channels (60) are at least partially directly delimited by the wall region (W) of the first chamber element (36) in the direction of passage (23).Motor vehicle, having an internal combustion engine, by means of which the motor vehicle can be driven, and having an exhaust tract (10) through which exhaust gas from the internal combustion engine can flow, which exhaust tract has at least one burner (12) according to one of the preceding claims.

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