Support structure for an exhaust gas aftertreatment unit and device having a honeycomb body and a support structure

Abstract

A support structure (1) for an exhaust gas aftertreatment unit, at least comprising an at least partially encircling frame (2) which predefines a plane (3), a plurality of spoke elements (4) at least partially connected to the frame (2) and having a course in the plane (3), wherein at least one spoke element (4) is configured with a plurality of elevations (6) transverse to the plane (3), and at least one stiffening element (5) which at least partially follows the course of the spoke element (4) and is connected to the spoke element (4) in the region of at least one elevation (6) of the plurality of elevations (6).

Description

[0001] Support structure for an exhaust aftertreatment unit and device with a honeycomb body and a support structure

[0002] The invention relates to a support structure for an exhaust gas aftertreatment unit. A support structure can be used in an exhaust gas aftertreatment unit to support a honeycomb body. Support pins can be used to connect the honeycomb body to the support structure. A honeycomb body can be used to heat exhaust gas flowing through the exhaust gas aftertreatment unit. The exhaust gas flows through the support structure and the honeycomb body.

[0003] To ensure the most unhindered flow of exhaust gas through the support structure, the support structure can have spoke elements mounted in a frame. This creates a high degree of openness for the exhaust gas to flow through. To minimize disruption of the exhaust gas as it flows through the support structure, the spoke elements are as thin as possible.

[0004] With particularly thin spoke elements, the support structure can be excited to vibrate by the exhaust gas flowing through it. These vibrations can generate excitations in the exhaust aftertreatment unit, potentially extending into its natural vibration range. However, such excitations in the exhaust aftertreatment unit must be prevented to avoid vibrations, noise, and / or damage.

[0005] Proceeding from this, it is the object of the invention to at least partially solve the problems described with reference to the prior art. In particular, a possibility is to be created with which vibrations in the support structure, which can lead to an excitation of a natural frequency of the exhaust gas aftertreatment unit, can be prevented. This object is achieved by the features of the independent claims. Further advantageous embodiments of the invention are specified in the dependent claims. It should be noted that features listed individually in the claims can be combined with one another in any technologically expedient manner and define further embodiments of the invention. Furthermore, the features listed in the claims are specified and explained in more detail in the description, wherein further preferred embodiments of the invention are presented.

[0006] A support structure for an exhaust gas aftertreatment unit contributes to solving this problem. The support structure has at least one at least partially circumferential frame that defines a plane. The support structure also has a plurality of spoke elements that are at least partially connected to the frame and extend in the plane, with at least one spoke element being designed with a plurality of elevations transverse to the plane. The support structure also has at least one stiffening element that at least partially follows the path of the spoke element and is connected to the spoke element in the region of at least one elevation of the plurality of elevations.

[0007] The exhaust gas aftertreatment unit can, for example, be arranged close to or even in a manifold of an internal combustion engine. Exhaust gases can flow from the internal combustion engine through the manifold into the exhaust gas aftertreatment unit. In the exhaust gas aftertreatment unit, the exhaust gases can be (thermally) pretreated, conditioned, and / or cleaned. In particular, the temperature, composition, and / or concentration of pollutants in the exhaust gas can be (specifically) influenced using different methods. A catalyst (carrier body) can be assigned to the exhaust gas aftertreatment unit, i.e., it can be located, for example, in the exhaust gas aftertreatment unit itself or connected to it. The support structure can hold or support objects in the exhaust gas aftertreatment unit.In particular, the support structure can serve to hold at least one catalyst carrier body, at least one honeycomb body and / or at least one sensor, which are assigned to the exhaust gas aftertreatment unit and are to be fixed in a predetermined position relative to it.

[0008] The frame of the support structure is at least partially circumferential. In most applications, it is advisable for the frame to encompass at least 70% of the circumference of the support structure, possibly even at least 85%. In many applications, a closed circumferential frame is also required. The frame defines an outer circumference of the support structure and can hold the support structure, for example, in a housing / shell of an exhaust gas aftertreatment unit. For this purpose, a circumferential shoulder can be provided on the housing / shell, against which the frame rests (axially supported).

[0009] The frame can define a plane. The plane, in particular, spans the associated exhaust aftertreatment unit or its casing. The exhaust gases are guided through the plane before or after flowing through the exhaust aftertreatment unit. The frame can, in particular, define an at least partially oval or circular area of ​​the plane. At points where the frame is not closed, the plane is defined as if the frame were continued at this point. Thus, the support structure is essentially plate-like.

[0010] A plurality of spoke elements of the support structure adjoin an inner side of the frame opposite the outer periphery. The spoke elements can extend along the plane. In particular, all spoke elements run in or along the plane. Nevertheless, the frame and the plurality of spoke elements can at least partially project beyond the plane. At least one spoke element of the plurality of spoke elements can project from one part to another (adjacent and / or opposite) part of an inner side of the frame. It is also possible to provide spoke elements that also connect other spoke elements to one another, possibly even without a (direct) connection to the (outer) frame.

[0011] At least one spoke element can have an at least partially bent or curved, possibly even S-shaped and / or meandering profile. At least one spoke element can extend from one part of the inside to another part of the inside of the frame, thus spanning the entire plane. It is also possible for the at least one spoke element to extend from one part of the inside of the frame to at least one other spoke element of the plurality of spoke elements.

[0012] At least one spoke element, preferably the majority of the spoke elements or even all spoke elements, has or have a plurality of elevations that protrude transversely, in particular (approximately) vertically, from the plane. The plurality of elevations can be at least an (integral) part of the at least one spoke element and, for example, can be punched or pressed into it. The plurality of elevations can comprise the same material as the at least one spoke element and can be manufactured or connected (in one piece) to it. The at least one spoke element can, on the one hand, have an indentation that forms an elevation opposite it. The indentation is therefore arranged opposite the elevation in the at least one spoke element and, in particular, defines the shape of the elevation. The spoke element can thus have a substantially uniform thickness (viewed perpendicular to the plane).

[0013] The support structure has at least one stiffening element. The at least one stiffening element can serve to stiffen the support structure and prevent vibrations in the support structure. The at least one stiffening element at least partially follows the course of at least one spoke element. It is possible for the at least one stiffening element to follow the course of the plurality of spoke elements and possibly also the frame of the support structure. It is possible for the at least one stiffening element to at least partially follow the course of at least one spoke element of the plurality of spoke elements and / or to at least partially follow the course of the frame. The geometry of the stiffening element can be designed depending on stiffness requirements and / or economical use of material.

[0014] The at least one stiffening element is connected to the spoke element in the region of at least one elevation of the plurality of elevations. One possibility is for the stiffening element to be placed directly on the elevation(s) and thus only to touch these. At least one elevation of the plurality of elevations can have a head surface that is aligned approximately parallel to the plane. Thus, the head surface of at least one elevation of the plurality of elevations can form an elevation plane. It is also possible for the plurality of elevations to have head surfaces arranged at different heights so that multiple elevation planes can be formed. The at least one stiffening element can rest on the plurality of elevations and / or on at least one of the plurality of elevations in at least one elevation plane and be connected thereto.

[0015] The at least one stiffening element can rest in the area of ​​at least one elevation of the plurality of elevations and be connected thereto. One (alternative or cumulative) possibility is for the stiffening element to immediately adjacently surround the elevation(s) and thus only touch their edge or the immediate surrounding area of ​​the spoke element. When the at least one stiffening element rests in the (surrounding) area of ​​at least one elevation, the stiffening element rests at least partially on at least one spoke element and can extend (also or partially) transversely and / or parallel to the plane. It is possible for an outer surface of the at least one stiffening element extending transversely to the plane to at least partially touch an outer surface of an adjacent elevation of the plurality of elevations, which also extends transversely to the plane, i.e. in particular to rest against a circumference of the elevation.

[0016] It is possible that the majority of the spoke elements and the frame opaquely cover at least one stiffening element or vice versa.

[0017] The at least one stiffening element can be integrally connected to the at least one spoke element. A material-to-material connection can be implemented as a weld seam or soldered connection, in particular produced by a resistance welding or soldering process. It is possible for the material-to-material connection of the at least one stiffening element to be produced with the at least one elevation or in the (adjacent) area of ​​the at least one elevation. At least the material of one stiffening element can be the same as the material of the majority of spoke elements and / or elevations to ensure a good material-to-material connection.

[0018] The at least one stiffening element preferably comprises or consists of a sheet metal. The frame, including the spoke elements, can also comprise a sheet metal or be provided with a (punched) sheet metal. The sheet metal of a stiffening element can have the same properties (thickness, width, material) as the sheet metal of the spoke elements or the frame. The thickness of the sheet metal can be selected such that, with a materially bonded connection of the at least one stiffening element to the plurality of spoke elements and / or elevations, unwanted vibrations of the support structure can be reduced or even prevented.

[0019] The at least one stiffening element, in particular designed as a sheet metal, can form a rib oriented perpendicular to the plane. A rib can also be designed such that its geometry or shape further stiffens the spoke elements. For example, waves in the rib can make it stiffer than a rib with an unbent structure. The number and / or size of the material connections in a rib can also be selected or adapted. It is possible for a (possibly self-stiffened) rib to be connected at just a few (1, 2, 3 or 4) points / elevations of a spoke element, thus already achieving a sufficiently stiffening function that can prevent undesirable vibrations in the support structure.

[0020] The sheet metal can comprise a perforated sheet with holes and webs arranged parallel to the plane. Such a perforated sheet can follow the path of the plurality of spoke elements and have holes and / or webs on at least one elevation of the plurality of elevations. The perforated sheet can be a stamped sheet. It is possible for the perforated sheet to comprise two different types of holes: (large) flow holes formed between the webs, and (small) holes provided in the webs for (flush) accommodation of elevations.

[0021] It can be provided that at least one of the plurality of elevations penetrates at least one hole in the perforated sheet. It is possible for the holes to correspond to the elevations and for the elevations to be adjacent to a circumferential inner surface of the holes. It is also possible for the inner surface of the holes to have a minimum distance in the range of 0.5 mm (millimeters) to 2.0 mm from the elevations.

[0022] Preferably, at least one elevation of a spoke element can rest against at least one web of the perforated sheet.

[0023] It is possible that at least one (further) footbridge bridges at least one (further) elevation, i.e. does not touch it and / or only partially touches it.

[0024] The perforated sheet can at least partially cover the frame and the plurality of spoke elements. The perforated sheet can completely cover the plurality of spoke elements and / or only leave the raised areas uncovered.

[0025] The support element can be designed in the form of a (congruent) sandwich sheet composite.

[0026] At least one bridging element can be provided in the support structure. The at least one bridging element can extend between the plurality of spoke elements without being (directly) connected to an outer frame. It is also possible for the at least one bridging element to extend from at least one spoke element to at least one other spoke element of the plurality of spoke elements. The bridging element can form an (internal) hub at which several or even all spoke elements terminate (centrally).

[0027] The openness of the support structure can be between 50% and 95%, and particularly preferably at least 65%, of the (framed) area of ​​the plane. The openness of the support structure describes the part of the plane that is neither covered by the frame nor by the majority of spoke elements of the support structure. The openness determines, in particular, the cross-section of the support structure through which the exhaust gas can flow.

[0028] For at least one spoke element of the plurality of spoke elements and / or at least one bridging element, a free spoke length of between 30 mm [millimeters] and 170 mm can be provided. Particularly preferably, the free spoke length is between 40 mm and 150 mm. The free spoke length is considered to be the length of a spoke element and / or a bridging element that lies between adjacent connections to another spoke element, to another bridging element and / or to the frame. For at least one spoke element of the plurality of spoke elements and / or at least one bridging element, an average spoke width of between 2 mm [millimeters] and 9 mm can be provided. Particularly preferably, the average spoke width is between 3 mm and 7 mm.The average spoke width is considered to be the average width of a spoke element and / or a bridging element over the free spoke length, particularly in areas without a raised area, even if this also requires a widening of the spoke element.

[0029] The object is further achieved by a device comprising at least one casing, a honeycomb body arranged in the casing, and at least one support structure proposed here. The casing can be designed as a (tubular) section of an exhaust line and / or as part of a manifold. The support structure can be mounted on the casing or connected to it (positively and / or non-positively and / or materially). The honeycomb body is supported on the support structure by support pins.

[0030] The honeycomb body can form an exhaust aftertreatment unit and be flowed through by exhaust gas. The support structure can be arranged upstream and / or downstream of the honeycomb body. The support structure can be arranged approximately parallel to an end face of the honeycomb body through which the exhaust gas flows in or out.

[0031] The frame of the support structure can be adapted to the shell section in which the support structure is arranged. An outer periphery of the frame can be at least partially mounted flush with an inner side of the shell and formed integrally with it. The frame is at least partially circumferential. It can run along the entire inner side of the shell. However, it is also possible for the frame to only partially circumferentially and for parts of the inner side of the shell not to connect to the outer periphery of the frame. The honeycomb body can be supported on the support structure (axially and / or spaced apart) with support pins. The support pins are supported on the plurality of spoke elements and connected to them. The shell thus holds the frame of the support structure, which in turn holds the honeycomb body in position with the support pins on the plurality of spoke elements.

[0032] The honeycomb body can be designed to be electrically heated. This makes it possible to direct an exhaust gas flowing through the casing through the support structure and through the honeycomb body, where it is heated.

[0033] The honeycomb body can have an axial length and a maximum extension parallel to the plane, and the ratio of length to extension can be between 2% and 15%, and particularly preferably at least 3.5%. This ratio results, for example, from the following honeycomb body configurations: an axial length (matrix length) of 9 mm to 11 mm and a maximum extension (diameter of the honeycomb body) of 80 mm to 300 mm. Such a ratio is advantageous for providing a space-saving heating output sufficient to heat the exhaust gas flow to a desired level.

[0034] The invention and the technical environment are explained in more detail below with reference to seven figures. The representations are schematic and not intended to illustrate proportions. The explanations given with reference to individual details of the figure are extractable and can be freely combined with facts from the above description, unless something else necessarily follows for a person skilled in the art or such a combination is explicitly excluded. They show schematically:

[0035] Fig. 1 : a support structure,

[0036] Fig. 2: a detailed view of the support structure with stiffening element as

[0037] sheet metal,

[0038] Fig. 3: a detailed view of the support structure with stiffening element as

[0039] Rib, Fig. 4: a detailed view of the support structure with stiffening element as

[0040] Perforated sheet and hole,

[0041] Fig. 5: a detailed view of the support structure with stiffening element as

[0042] Perforated sheet and web,

[0043] Fig. 6: a support structure with rib, and

[0044] Fig. 7: a device with shell, honeycomb body and support structure.

[0045] Fig. 1 shows a support structure 1, which is punched out of sheet metal, for example. The support structure 1 comprises a frame 2 that defines a plane 3. The frame 2 is not completely circumferential and has an open end 19. Spoke elements 4 and bridging elements 18 extend in plane 3. The spoke elements 4 partially or only partially fill the plane 3 and connect parts of the frame 2 to one another. The bridging elements 18 partially or also only partially fill the plane 3 and connect spoke elements 4 to one another.

[0046] In addition, Fig. 1 shows a stiffening element 5 that is connected to the support structure 1. In Fig. 1, the stiffening element 5 is attached to elevations 6 on the spoke elements 4 on an underside of the support structure 1. The stiffening element 5 follows the course of the support structure 1, in particular the course of the frame 2 and the spoke elements 4. The stiffening element 5, which is also punched from a sheet metal and made of the same material as the support structure 1, is integrally connected to the support structure 1. The stiffening element 5 is thus connected to the spoke elements 4 of the support structure 1 at several points and stiffens the support structure 1.

[0047] Fig. 2 shows a detailed view of the support structure 1 with the stiffening element 5 as a sheet metal part 8. The sheet metal part 8 can at least partially follow the course of the spoke elements 4 and the frame 2. The spoke element 4 of the support structure 1 can be seen, which has a raised portion 6 that protrudes transversely from the plane 3. The raised portion 6 forms a head surface 7 that lies parallel to the plane 3. The sheet metal part 8 rests on the head surface 7 of the raised portion 6 and is integrally connected to it by resistance welding. The sheet metal part 8 covers the head surface 7 (almost) completely.

[0048] Opposite the elevation 6, an indentation 16 can be seen in Fig. 2 in the spoke element 4. A support pin 15 is mounted in the indentation 16, which, like the elevation 6, protrudes from the plane 3. However, the support pin 15 protrudes from the plane 3 in the opposite direction to the elevation 6. The support pin 15 is integrally connected to the spoke element 4 in the indentation 16 by a soldered joint.

[0049] Fig. 3 shows a detailed view of the support structure 1 with a stiffening element 5 as rib 9. The rib 9 can at least partially follow the course of the spoke elements 4 and the frame 2. The rib 9 has a surface that rests on the head surface 7 of the elevation 6 and is integrally connected thereto by resistance welding. The rib 9 partially covers the head surface 7.

[0050] Fig. 4 shows a detailed view of the support structure 1 with a stiffening element 5 as a perforated plate 10 with a hole 11. The perforated plate 10 can at least partially follow the course of the spoke elements 4 and the frame 2. The perforated plate 10 rests on the spoke element 4 outside the elevation 6 and is integrally connected thereto by soldering or resistance welding. The hole 11 of the perforated plate 10 omits the elevation 6 and does not touch it. The perforated plate 10 has an outer surface that is not connected to the spoke element 4 and runs parallel to the head surface 7 of the plane 6.

[0051] Fig. 5 shows a detailed view of the support structure 1 with a stiffening element 5 as a perforated plate 10 with a web 17. The perforated plate 10 can at least partially follow the course of the spoke elements 4 and the frame 2. The perforated plate 10 rests on the spoke element 4 and is integrally connected to it by soldering or resistance welding. The web 17 protrudes beyond the elevation 6 and runs parallel to the head surface 7. The web 17 and the perforated plate 10 do not touch the elevation 6.

[0052] Fig. 6 shows a support structure 1 with ribs 9. The ribs 9 each follow one of the spoke elements 4. The ribs 9 completely touch the elevations 6 and are connected thereto.

[0053] Fig. 7 shows a device 14 with a casing 12, an (electrically heatable) honeycomb body 13, and the support structure 1 from Fig. 1. The support structure 1 is arranged in the casing 12. The honeycomb body 13 is arranged behind the support structure 1 in an axial direction of the casing 12. The honeycomb body 13 is held to the support structure by support pins 15 (not shown) and can be supplied with electrical current via the electrodes shown, which protrude beyond the casing 12. The honeycomb body 13 is formed from corrugated and smooth metal foils that are joined to form packages and arranged in a meandering shape.

[0054] Reference symbol

[0055] 1 support structure

[0056] 2 frames

[0057] 3 levels

[0058] 4 spoke element

[0059] 5 stiffening element

[0060] 6 Survey

[0061] 7 Head area

[0062] 8 sheet metal

[0063] 9 rib

[0064] 10 perforated sheets

[0065] 11 holes

[0066] 12 coats

[0067] 13 honeycomb bodies

[0068] 14 Device

[0069] 15 Support pin

[0070] 16 Imprint

[0071] 17 jetty

[0072] 18 Bridging element

[0073] 19 open ending

Claims

Claims 1. Support structure (1) for an exhaust gas aftertreatment unit, at least comprising an at least partially circumferential frame (2) which defines a plane (3), a plurality of spoke elements (4) which are at least partially connected to the frame (2) and have a course in the plane (3), wherein at least one spoke element (4) is designed with a plurality of elevations (6) transverse to the plane (3), and at least one stiffening element (5) which at least partially follows the course of the spoke element (4) and is connected to the spoke element (4) in the region of at least one elevation (6) of the plurality of elevations (6).

2. Support structure (1) according to the preceding claim, wherein the at least one stiffening element (5) is integrally connected to the at least one spoke element (4).

3. Support structure (1) according to one of the preceding claims, wherein the at least one stiffening element (5) comprises a sheet metal (8).

4. Support structure (1) according to claim 3, wherein the sheet (8) forms a rib (9) oriented perpendicular to the plane (3).

5. Support structure (1) according to one of claims 3 or 4, wherein the sheet (8) comprises a perforated sheet (10) with holes (11) and webs (17) arranged parallel to the plane (3).

6. Support structure (1) according to claim 5, wherein the at least one elevation (6) penetrates the holes (11).

7. Support structure (1) according to claim 5 or 6, wherein the at least one elevation (6) bears against the webs (17).

8. Support structure (1) according to one of claims 5 to 7, wherein the perforated sheet (10) covers the frame (2) and the plurality of spoke elements (4).

9. Support structure (1) according to one of the preceding claims, wherein at least one bridging element (18) is provided in the support structure (1) which extends between the plurality of spoke elements (4).

10. Support structure (1) according to one of the preceding claims, wherein an openness of the support structure (1) is at least 65% of an area of the plane (3).

11. Support structure (1) according to one of the preceding claims, wherein at least one spoke element (4) and / or at least one bridging element (18) has a free spoke length in the range of 30 mm to 170 mm.

12. Support structure (1) according to one of the preceding claims, wherein at least one spoke element (4) and / or at least one bridging element (18) has an average spoke width in the range of 2 mm to 9 mm.

13. Device (14) comprising at least one casing (12), a honeycomb body (13) arranged in the casing (12), and at least one support structure (1) according to one of the preceding claims, which is mounted on the casing (12) and on which the honeycomb body (13) is supported by support pins (15).

14. Device (14) according to claim 12, wherein the honeycomb body (13) is designed to be electrically heated.

15. Device (14) according to claim 12 or 14, wherein the honeycomb body (13) has an axial length and a maximum extension parallel to the level (3) and the ratio of length to extent is at least 2% to 15%.

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