Exhaust aftertreatment device

Abstract

Exhaust gas aftertreatment device (12) for aftertreating an exhaust gas of an internal combustion engine (6), comprising a first aftertreatment component (1) and a second aftertreatment component (2), wherein the first aftertreatment component (1) and the second aftertreatment component (2) are arranged together in a housing (13), wherein the two aftertreatment components (1, 2) are firmly connected to one another at the end faces, characterized in that the first component (1) against which the exhaust gas flows first has a greater cell density than the second component (2) located behind it.

Description

The present invention relates to an exhaust gas aftertreatment device for aftertreatment of an exhaust gas of an internal combustion engine, having a first aftertreatment component and a second aftertreatment component. The first and the second aftertreatment component are arranged together in a housing. The invention further relates to a motor vehicle which is driven by an internal combustion engine and is equipped with an exhaust gas aftertreatment device according to the invention.In the prior art, various measures are known for improving the conversion of exhaust gases after a cold start, which measures provide, for example, the targeted designs of substrates and coatings, the use of heating catalysts, burners or motor heating measures.Furthermore, for improving the exhaust gas after-treatment after a cold start, the arrangement of an SCR catalyst (selective catalytic reaction) upstream of an SCR diesel particulate filter (SDPF) is fundamentally known. As a rule, however, an SDPF has a lower amount of washcoat and at the same time a higher thermal mass than an SCR catalyst because of its lower cell density. This leads, for example, to a significantly poorer light-off behavior in the case of a cold start. This means that the desired exhaust gas after-treatment only begins significantly later than is the case with an SCR catalyst. In order to compensate for this disadvantage, the approach is followed, for example, to arrange an SCR catalytic converter upstream of the SDPF.The solutions known up to now have, however, different disadvantages. Thus, in the design, various conflicts arise with regard to, for example, the cold starting behavior, the NOx conversion, the filtering capacity and also the installation space required for the exhaust gas aftertreatment.When an SCR catalytic converter is arranged upstream of the SDPF, another conflict of goals occurs with regard to functionality on the one hand and the tendency to achieve as low a fuel consumption as possible. Thus, the NOx conversion should be as high as possible and should take place as quickly as possible, while at the same time the additional fuel consumption should be as low as possible and should not increase. As a rule, however, the fuel consumption increases, since an additional heating of the SCR catalytic converter by means of fuel is required during the regeneration of the SDPF. A second conflict of goals arises against the background of the generally only very small available installation space close to the engine. On the one hand, it is desirable to provide a large volume of the SCR catalyst in order to achieve a high NOx conversion. On the other hand, a large SDPF volume is desirable in order to be able to absorb deposits of ash and soot over as long a time as possible between the regeneration processes, as a result of which the regeneration is less frequently required and fuel can be saved.DE 10 2014 207 530 A1 discloses a catalytic converter assembly and a device containing the assembly for purifying exhaust gases of an internal combustion engine.DE 601 12 463 T2 is directed to a particle filter with a honeycomb structure.It is therefore the object of the present invention to at least partially solve the problems resulting from the prior art. In particular, a particularly compact and durable exhaust gas aftertreatment device is to be provided, which enables the most complete exhaust gas aftertreatment possible.To achieve these objects, an exhaust gas aftertreatment device according to the features of patent claim 1 and a motor vehicle according to patent claim 9 contribute.Advantageous refinements are the subject matter of the claims that are formulated as a function. The features individually listed in the patent claims can be combined with one another in a technically expedient manner and can be supplemented by explanatory facts from the description and / or details from the figures, wherein further embodiment variants of the invention are shown.The proposed exhaust gas aftertreatment device for aftertreatment of an exhaust gas of an internal combustion engine has a first aftertreatment component and a second aftertreatment component, wherein the first and the second aftertreatment component are arranged jointly in a housing. It is characterized in that the two aftertreatment components are firmly connected to one another.Aftertreatment components are components of an exhaust gas aftertreatment device that are suitable for causing a conversion / conversion of components of the exhaust gas, filtering substances from the exhaust gas or introducing substances into the exhaust gas.The cell density is understood here to mean the number of cells per unit area through which flow takes place in the cross section of the aftertreatment component through which flow takes place. This means that the greater the cell density of an aftertreatment component, the more cells through which flow can pass are arranged in their cross section per unit area.The washcoat is the constituent arranged on the surface of the aftertreatment components, which component provides the cracked surface for a catalytically active material and thus brings about the desired reactive aftertreatment of the exhaust gas.The present invention has recognized that it is advantageous to use two aftertreatment components in an exhaust gas aftertreatment device and thereby to firmly connect the two aftertreatment components to one another on the end face. The fixed connection can in particular not be via a common housing but also without a housing. In particular, it is possible for the fixed connection to be realized (only) via the end faces of the aftertreatment components lying opposite one another. It is possible that the mutually opposite end faces of the post-treatment components are arranged substantially planar and / or parallel to one another and are formed with the ends of the walls forming the cells. It is possible for the end faces to form a cracked contour, wherein the mutually opposite end faces of the aftertreatment components form converging or matching elevations and depths in the end faces. The fixed connection can be formed via the ends of the walls and / or via separate components, wherein these cooperate (preferably exclusively) with the opposite end faces, walls and / or cells. The separate components may perform an auxiliary function for at least one of the two aftertreatment components, such as a flow blocker for one or more cells. A separate component may be a filter plug or the like. The fixed connection can comprise a cohesive connection medium, e.g. an adhesive. A "fixed" connection in this sense is in particular one which withstands the ambient conditions in a (mobile) exhaust system.For example, the first aftertreatment component may be formed as a disk-shaped flow-through substrate and the second aftertreatment component may be formed as a large volume filter substrate. Thus, in particular, a combined flow-through filter substrate is proposed. Since as a rule only a very limited installation space is available for the exhaust gas aftertreatment device and this installation space can be particularly expensive, in particular close to the engine, the present invention helps to save this installation space. The present invention has recognized that in practice it is often already sufficient to use an SCR catalyst that has only a small catalyst volume. This is particularly useful when only a greatly restricted installation space is available for the exhaust gas aftertreatment.The invention now makes it possible for the first aftertreatment component to be designed to be disk-shaped and thus particularly narrow. This makes it possible to save the costable installation space and instead to use it for a diesel particulate filter which is arranged directly downstream, for example. In this case, the larger the volume of a diesel particulate filter, the less frequently regeneration is required. At the same time, the quantity of fuel required for the regeneration is also reduced with the number of regeneration processes required. In particular, the cross section of the first aftertreatment component available for the exhaust gas flowing through is designed in terms of shape and size exactly as the cross section of the second aftertreatment component. This makes it possible, for example, to avoid transition funnels which would otherwise be required to connect different cross sections to one another. By eliminating such transition funnels, the installation space required for this purpose can ultimately also be saved.The invention is thus able to arrange two aftertreatment components directly one behind the other in a particularly compact manner and to treat or clean the exhaust gas flowing through in two successive treatment steps. Furthermore, the assembly of an exhaust gas aftertreatment device configured in this way is also simplified, since both aftertreatment components can be arranged together in the housing. In particular, the difficulty of fastening the post-treatment component in the housing is thereby dispensed with if one of these post-treatment components is formed particularly narrow or disc-shaped. By now firmly connecting both aftertreatment components together, they can be positioned much better within the housing and permanently, securely and reliably secured therein.Both the first and the second post-treatment component can be designed as ceramic honeycomb bodies which are manufactured, for example, from a material such as cordierite, silicon carbide, aluminum titanate or the like. The honeycomb bodies can have the same or different cell densities as required.In particular, for the purpose of further developing the invention, it can be provided that the first component, which has first flowed against it in a flow direction of the exhaust gas, has a greater cell density than the second component situated behind it. For this purpose, for example, the substrate of the first post-treatment component and the substrate of the second post-treatment component can be manufactured in separate extrusion processes.Thus, the cell density of the substrate of the first aftertreatment component, such as an SCR catalyst, can be increased by a factor of 4 compared to the cell density of the subsequent second aftertreatment component, such as a filter substrate of a diesel particulate filter. For this purpose, the SCR catalyst can be designed, for example, with a cell density of 1200 cpsi (cells per square inch) and the diesel particle filter (SDPF) with a cell density of 300 cpsi. Furthermore, filter plugs can be provided in the filter substrate, which alternately close the opposite channels of the particle filter, so that a closed filter system is produced. Furthermore, in one embodiment, filter plugs can likewise be provided in a part of the channels at least on the side of the first aftertreatment component which is directly adjacent to the second aftertreatment component. If the first aftertreatment component has, for example, the previously mentioned four times the cell density compared to the second aftertreatment component, then four adjacent channels can be closed there by a filter plug. The post-treatment components prepared in this way can then be permanently and integrally connected to one another at the respectively opposite filter plugs. In this case, a sufficient connection between the two aftertreatment components can be produced at the plurality of plugs.The finished substrates are then preferably coated with an active coating, the so-called washcoat. For this purpose, coatings can be applied, for example, to the first aftertreatment component designed as a flow-through substrate, which act as an SCR catalyst, as a passive NOx adsorber, as an NOx storage catalyst, as an oxycate or as a three-way catalyst. Coatings can be applied to the second aftertreatment component, which is configured as a filter substrate, and which act as an SDPF coating, as an NOx storage cat, as an oxycate or as a three-way cat.In principle, however, the greater cell density of the first aftertreatment component offers the possibility of applying more washcoat to the substrate and thus improving the catalytically active surface area and / or effectiveness of the exhaust aftertreatment in this step.Alternatively, however, other ratios of the cell densities of the first and second aftertreatment components can also be used. This makes it possible, for example, to provide embodiments which are designed to be optimized with respect to counterpressure and in which the filter plugs of the first aftertreatment component have a smaller cross section than the filter plugs of the second aftertreatment component adjoining the latter. However, it is always to be noted here that sufficient strength can be produced in the connection of the aftertreatment component via the opposite filter plugs. If necessary, it is also possible to have the filter plugs of one aftertreatment component project into the opposite free cells or filter channels and thereby increase the strength of the connection of the two aftertreatment components.In particular, it can be provided that the first aftertreatment component has a ratio of its length in the flow direction of the exhaust gas to its diameter of less than 0.7, preferably of less than 0.5 and in particular of less than 0.3. While individual disk-shaped aftertreatment components generally had to have a minimum length that was greater than their 0.7 times diameter, with the present invention and the associated connection of the two aftertreatment components, it is now also possible to realize narrower components with ratios of significantly less than 0.7 and to accommodate them in a stable manner in the housing. This step of the manufacturing process is also called canning. A disk-shaped aftertreatment component of such a particularly slender design has a small installation space requirement and, owing to the reduced mass, simultaneously exhibits a particularly rapid response behavior, for example after a cold start of the internal combustion engine.It is also advantageous if the first aftertreatment component is formed by means of a flow-through substrate. Such a flow-through substrate has open cells through which the exhaust gas can flow freely. This type of substrate is suitable in particular for SCR catalysts.Another advantageous refinement provides that the second aftertreatment component is formed by means of a filter substrate. The cells of a filter substrate are in this case alternately closed with plugs at the opposite ends, with the result that the exhaust gas has to flow through a cell wall from one cell to an adjacent cell in the path from an inlet side to an outlet side before it can flow out again from the closed-cell aftertreatment component configured in this way. This design is suitable in particular for diesel particulate filters, such as DPF or SDPF.It is also particularly advantageous if the first aftertreatment component and the second aftertreatment component are firmly connected to one another by a (separate) connecting means.A connecting means may be at least one connecting element, which penetrates at least partially into a cell or a channel of the first and / or second aftertreatment component, for example. The connecting element can be designed as a filter plug. It is possible for the connecting element to be designed positively with at least one channel or cell of an aftertreatment component. This can also apply to different sizes and / or shapes of the cells or channels of both aftertreatment components and or to a different number in one aftertreatment component each.At least one connecting element can have a different shape at its two ends, which cooperate with the respective other aftertreatment component, in particular a cross section that differs from one another.A slender disc-shaped first component can then be securely mounted together with the second component and permanently and securely fastened in the housing. This can be effected, for example, by means of a ceramic adhesive, with which, for example, the SCR catalyst and the SDPF can be permanently bonded together at the sealed and mutually opposite channels. The adhesive may cooperate with a connector and / or directly with the aftertreatment components.In this case, the plurality of filter plugs connected to one another can produce an adequate adhesive surface and thus adhesive force. This adhesion force can be increased even further if the filter plugs of one aftertreatment component are designed such that they project into the free cells of the adjacent aftertreatment component and are connected in this state by means of the connecting means.It is particularly favorable if the post-treatment components have markings and / or guide means which facilitate or ensure the correct joining and the correct orientation of the post-treatment components with respect to one another.This makes it possible to prevent the aftertreatment components from being connected to one another in a manner rotated with respect to one another. In particular, the substrates of the aftertreatment components to be connected can be shaped complementarily to one another in such a way that they can be joined together only in a specific position.It is very particularly advantageously provided that the first and the second aftertreatment component are produced by means of an additive production method and are formed in one piece. In particular, the production by means of a 3D printing method enables a much greater freedom of design in the design of the substrates of the aftertreatment components. Thus, for example, with additive manufacturing methods, undercuts can also be manufactured which cannot be produced with the previously customary manufacturing methods. In particular, the design of the filter plugs can be produced particularly easily using this production method. A further advantage when using additive manufacturing methods is that the first and second aftertreatment components can be manufactured in one piece. Subsequent connection of the two post-treatment components can thus be omitted.In particular, it can also be provided that the first post-treatment component has a cell density of at least cells 500 cpsi and the second post-treatment component has a cell density of at most 900 cpsi. Ideally, the cell density of the first aftertreatment component is above the cell density of the second aftertreatment component in order to be able to present the largest possible surface area on the disk-shaped first aftertreatment component for applying a washcoat and at the same time to achieve a low counterpressure of the exhaust gas flowing through above the second aftertreatment component.It has proven to be particularly suitable materials for the production of the substrates of the post-treatment components if these are produced from at least one of the following substances cordierite, silicon carbide or aluminum titanium oxide.In particular, a motor vehicle, such as a passenger car or a commercial vehicle, with an internal combustion engine, will further benefit from the present invention if the latter is equipped with an exhaust gas aftertreatment device according to the present invention, since the available installation space is utilized in an improved manner for the exhaust gas aftertreatment. Thus, for example, the exhaust gas after-treatment can be carried out by means of two after-treatment components and a large storage volume of the SDPF can be obtained at the same time. The improved exhaust gas aftertreatment can thus be achieved without additional fuel consumption. In addition, the service life of the exhaust gas aftertreatment device is improved by arranging both aftertreatment components jointly and securely in the housing.In particular, the invention proposes the use of a "fixed connection" disclosed herein for two aftertreatment components for space-saving, efficient and / or flow-matched integration into an exhaust system. This applies in particular to the combination of catalyst carrier and filter body.As a precautionary measure, it should be noted that the numerical words used here ("first", "second",... ) are primarily (only) used for distinguishing a plurality of articles, sizes or processes of the same type, that is to say in particular do not necessarily specify a dependence and / or sequence of these articles, sizes or processes with respect to one another. If a dependence and / or sequence is required, this is explicitly stated here or it is obvious to the person skilled in the art when studying the specifically described configuration.The invention and the technical field are explained in more detail below with reference to the attached figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments listed. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other constituent parts and findings from the present description. In particular, it should be pointed out that the figures and in particular the size relationships illustrated are only schematic. The following are shown: FIG. 1 : a front view with a lateral sectional view of a first exhaust gas aftertreatment device according to the invention; FIG. 2 : front view of a plug image with a cell density ratio of 2.25; FIG. 3 : front view of an irregular plug pattern; FIG. 4 : a front view with a lateral sectional view of a second exhaust gas aftertreatment device according to the invention; FIG. 5 : a front view with a lateral sectional view of a third exhaust gas aftertreatment device according to the invention, and FIG. 6 : shows a motor vehicle with an exhaust gas aftertreatment device according to the present invention.In FIG. 1, a first aftertreatment component 1 and a second aftertreatment component 2 are shown in a front view and a lateral sectional illustration. The left-hand front view shows a plurality of vertical partitions 3 and horizontal partitions 4 extending within the first aftertreatment component 1 and the second aftertreatment component 2. The partitions 3 and 4 each enclose cells 5 through which the exhaust gas to be treated of an internal combustion engine 6, not shown, flows. The cells 5 have a square cross-sectional area. Deviations from this basic shape occur only in the edge region, where the rectangular cross-sectional area is bounded by a circular outer surface 7 of the aftertreatment components 1 and 2. In the manufacturing process, it is helpful to apply a mark on the periphery of the substrates to enable the substrates to be later joined together with the correct alignment.For this purpose, two markings 8 are applied to the outer surface 7 on an upper side of the aftertreatment components 1, 2. The markings 8 serve to facilitate and ensure the correct assembly of the aftertreatment component 1, 2. In the present example, the markings 8 are each applied in the region of those end faces of the aftertreatment components 1, 2 which are to be brought into contact with one another. Furthermore, the markings 8 are arranged in such a way that, when they are aligned one behind the other, the vertical separating walls 3 and horizontal separating walls 4 of the two aftertreatment components 1, 2 are each arranged exactly one behind the other. The marking 8 thus serves to simplify the alignment of the post-treatment component in 1, 2 with respect to one another. On the right side of FIG. 1, the sectional view along the line A-A is shown. In the side view, it can be clearly seen that the first post-treatment component 1 arranged on the left is designed as a flow-through substrate. That is, in principle, the exhaust gas to be treated can flow freely through the cells 5. In the embodiment shown here, half of the cells 5 are closed by filter plugs 9. These filter plugs 9 are also shown again in the left front view. On the right side of the sectional view, the second aftertreatment component 2 is furthermore shown, which is constructed by means of a filter substrate. This means that the cells 5 are alternately closed on the left-hand inlet side or the right-hand outlet side with a filter plug 9. This has the result that, for example, an exhaust gas entering from the first aftertreatment component 1 on the left into the second aftertreatment component 2 can initially only enter cells 5 which are open on the left, i.e. are not closed by a filter plug. During the further course of the flow, however, the exhaust gas that has entered is then prevented from exiting again on the right side of the second aftertreatment component 2 by the filter plugs 9 of these cells 5 arranged on the right side. In order to be able to emerge on the right-hand side, the exhaust gas must first pass through a vertical partition 3 or a horizontal partition 4 into one of those adjacent cells 5, the right-hand side of which is not closed by a filter plug 9. During this transition through one of the partitions 3, 4, the filtering of diesel particles takes place. This is thus a diesel particle filter. In addition to the pure mechanical filter effect, reactive surfaces can also be provided on the partition walls, which are designed, for example, to act as an oxidation catalyst, as an SCR catalyst or in another known manner. The coating of the substrates with a washcoat and catalytic coating can be carried out before or after the bonding together. Even in the bonded state, different catalyst coatings and coating amounts can be applied, since the combined component can be coated from both sides. For example, the two post-treatment components can be coated by vacuum or dip methods over the entire length or over a proportional length. If only partial lengths are coated, this results in different coating sequences and / or coating amounts in the flow direction.An SCR coating can be applied to the flow-through substrate and an SDPF coating can be applied to the filter substrate. Alternatively, the following coatings can be applied on the flow substrate alone or in combination with one another: passive NOx adsorber, NOx storage cat, oxycate, three-way cat. The following alternative coatings can be applied to the filter substrate alone or in combination with one another: NOx storage cat, oxycate, three-way cat.Both the disk-shaped flow-through substrate of the first post-treatment component 1 and the filter substrate of the second post-treatment component 2 can be manufactured separately by means of an extrusion method. In the embodiment shown, the cell density of the first aftertreatment component 1 is four times as high as the cell density of the second aftertreatment component 2.While the cell densities shown in the figures are to be understood schematically, in practice, for example, cell densities of 300 cpsi (cells per square inch) for the SDPF of the second aftertreatment component 2 and 1200 cpsi for the SCR catalyst of the first aftertreatment component 1 can be used. In the embodiment shown, the filter plugs 9 on both aftertreatment components 1, 2 are of identical size. That is, a filter plug 9 of the first post-treatment component 1 closes 4 cells 5, while an equally sized filter plug 9 of the second post-treatment component 2 closes only one cell 5. The two aftertreatment components 1, 2 are joined together by connecting the filter plugs 9 of the same size and positioned opposite one another.In addition to the above-described ratio of the cell density with a value of 4, however, other ratios, such as with a value of 2.25, can also be used.FIG. 2 shows a possible plug pattern for such a ratio of the cell density of flow substrate to filter substrate of 2.25. Here, for example, the cell density of the flow substrate is 675 cpsi and that of the filter substrate is 300 cpsi or, in the case of high-cell substrates, a cell density of the flow substrate is 1350 cpsi and of the filter substrate is 600 cpsi.In this embodiment, the filter plugs 9 of the flow-through substrate have a smaller area than the plugs of the filter substrate. More filter plugs 9 can be used on the flow-through substrate. The filter plugs 9 of the flow-through substrate are preferably arranged in such a way that they only close those cells of the filter substrate which are already already already closed on the contacting side. This then results in embodiments optimized for counterpressure. In practice, however, it may also be necessary to seal the flow-through substrate in cells which then adjoin sealed cells of the filter substrate. However, as a result, proportionally free channels of the filter substrate are then closed, as a result of which the exhaust gas back pressure is increased in this case.Since in the embodiment according to FIG. 2 the filter plugs 9 of the first aftertreatment component have a different size than the filter plugs 9 of the second aftertreatment component, it is to be ensured that contact occurs between the filter plugs 9 of the aftertreatment component in 1, 2 on a sufficiently large area. This contact surface is required in order to then be able to connect the aftertreatment components to one another by means of a connecting means with sufficient strength. If there is not a sufficient adhesive surface between the filter plugs 9, the plugs 9 of one of the aftertreatment components 1, 2 can alternatively project into the free cells 5 of the respectively adjacent aftertreatment component 1, 2 in order to achieve an increase in the strength of the connection between the two aftertreatment components 1, 2 when connecting by means of an adhesive.Figure 3 shows another possible plug pattern in which the design can be made without a common reference surface.In this case, too, the filter plugs 9 of the flow substrate are to be set in such a way that they generate the lowest possible exhaust gas back pressure. As illustrated, this can lead to an uneven plug pattern in the flow substrate, wherein the filter plugs 9 of the two aftertreatment components 1, 2 have cross sections of different sizes as seen in the flow direction. During the design, care must merely be taken to ensure an adhesive surface sufficiently large for secure connection of the aftertreatment components 1, 2. Overall, however, it is also possible with this uneven plug pattern to keep the exhaust gas back pressure relatively low.FIG. 4 shows another embodiment in which a substrate has been produced by means of an additive production method, such as, for example, a 3-D printing, which substrate is formed integrally and simultaneously comprises the first aftertreatment component 1 and the second aftertreatment component 2. In the sectional illustration A-A, the cells 5 arranged on the left side are again formed with a cell density which is greater by a factor of 4 than the cell density of the cells 5 shown on the right side of the sectional illustration. In this embodiment, only the larger cells 5 are alternately closed on the left side and in good time by means of filter plugs 9, in order in this way to form a filter substrate. Since this substrate is formed in one piece and no subsequent connection of the first aftertreatment component 1 to the second aftertreatment component 2 is required any more, additional filter plugs 9 are no longer required in the left-hand section, which is formed as a flow-through substrate. The one-piece substrate thus produced can then be coated with different washcoats as described above and as required.FIG. 5 shows yet another variant of a substrate which can be produced by means of 3-D printing. On the right-hand side of FIG. 5, it can be easily seen in the sectional illustration A-A that the larger cells 5 of the filter substrate, which cells are alternately closed by means of the filter plugs 9, are arranged in an interlaced manner with the open cells 5 of the flow-through substrate. The open cells 5 of the flow-through substrate and the closed cells 5 of the filter substrate overlap each other in the flow direction and in turn each have a rectangular cross section. The leg length of the cross section of the open cells 5 is half as long as the leg length of the cross section of the closed cells 5. In this embodiment too, subsequent joining of the flow and filter substrates is no longer necessary because of the one-piece nature.In summary, it can be stated that the substrate shown can be produced by means of a 3-D printing in a particularly simple and efficient manner in order subsequently to be provided with a suitable washcoat in a known manner.All previously described and shown embodiments of the post-treatment components and thus of the combined flow-through filter substrate can also be implemented with other cross-sectional shapes instead of the rectangular cross-sections shown. Due to the optimum use of space, the use of cells with a hexagonal or honeycomb cross section is also particularly appropriate for this purpose.FIG. 6 finally shows a motor vehicle 10 with an internal combustion engine 6, the exhaust gases of which are discharged via an exhaust system 11. An exhaust gas aftertreatment device 12 having a housing 13 is a component of the exhaust system 11, said housing being arranged close to the internal combustion engine 6 by the engine. The aftertreatment components 1, 2 described above are arranged in the housing 13, wherein the two aftertreatment components 1, 2 are optionally formed in one piece by a subsequent connection or by an additive manufacturing method. Additional aftertreatment components may be present in the exhaust system 11 in additional housings.List of reference characters1 First aftertreatment component 2 Second aftertreatment component 3 Vertical partition 4 Horizontal partition 5 Cell 6 Internal combustion engine 7 Outer surface 8 Mark 9 Filter plug 10 Motor vehicle 11 Exhaust system 12 Exhaust aftertreatment device 13 Housing

Claims

Exhaust gas aftertreatment device (12) for aftertreatment of an exhaust gas of an internal combustion engine (6), having a first aftertreatment component (1) and a second aftertreatment component (2), wherein the first aftertreatment component (1) and the second aftertreatment component (2) are arranged jointly in a housing (13), wherein the two aftertreatment components (1, 2) are fixedly connected to one another at the end face, characterized in thatthe first component (1) which has flowed on first in a flow direction of the exhaust gas has a greater cell density than the second component (2) which lies behind it.The exhaust gas aftertreatment device (12) according to claim 1, characterized in that the first aftertreatment component (1) has a length to diameter ratio of less than 0.7, preferably less than 0.5, and in particular less than 0.3.Exhaust gas aftertreatment device (12) according to one of the preceding claims, characterized in that the first component (1) is formed by means of a flow substrate.Exhaust gas aftertreatment device (12) according to one of the preceding claims, characterized in that the second component (2) is formed by means of a filter substrate.Exhaust gas aftertreatment device (12) according to one of the preceding claims, characterized in that the first aftertreatment component (1) and the second aftertreatment component (2) are fixedly connected to one another by a separate connecting means.The exhaust gas after-treatment device (12) according to the preceding claim, characterized in that the separate connecting means comprises a plurality of filter plugs (9).Exhaust gas aftertreatment device (12) according to one of the preceding claims, characterized in that the first and the second aftertreatment component (1, 2) are produced by means of an additive production method and are formed in one piece.Exhaust gas aftertreatment device (12) according to one of the preceding claims, characterized in that the substrate for the aftertreatment component (1, 2) is produced from at least one of the following substances cordierite, silicon carbide or aluminium titanium oxide.Motor vehicle having an internal combustion engine (6) and an exhaust gas aftertreatment device (12) according to one of the preceding claims.

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