DE102004058268B4 - Reinforced housing of an exhaust gas purification component - Google Patents

Abstract

Exhaust gas purification component (1) comprising at least one body (2) and at least one housing (3, 4) which at least partially surrounds the at least one body (2), characterized in that the at least one housing (3, 4) with superimposed stiffening structures (5) is provided, wherein the stiffening structures (5) are formed only radially outward and wherein the at least one body (2) and the at least one housing (3, 4) are joined together by joining technology.

Description

The invention relates to an exhaust gas purification component comprising at least one body and at least one housing which at least partially surrounds the at least one body.

In the design of such housing for emission control components a variety of different criteria are taken into account. For example, the housing must withstand the thermal and dynamic loads in the exhaust system of automobiles. In addition, more cost factors are to be considered, but such exhaust gas cleaning components are often produced in mass production. The housings serve the structural integrity of the exhaust gas purifying component as well as a mediator for fixation in superordinate exhaust systems as well as for the heat transfer from the body to the environment. Therefore, the housing is an essential component in terms of exhaust gas purification components, which has also been the subject of many technical developments.

So goes for example from the EP 0 799 369 B1 a double-walled housing, especially for exhaust catalysts of motor vehicles. The objective in the development of the housing described there was to provide a simple and inexpensive to produce, a great stability and favorable thermal insulation properties exhibiting housing. This has been achieved by a double-walled housing having an inner shell and an outer shell, wherein the shells close to each other near the end faces and at least partially spaced therefrom by inwardly directed embossments of the outer shell. The embossings are preferably formed circumferentially, so that a kind of annular channels arise between the coats, which represent a thermal insulation.

Also in the German utility model DE 89 10 107 U1 a jacket tube for a metallic honeycomb body is described. With regard to the different shapes of such housings, cylindrical, oval or the like, it has been found that undesired deformations can occur as a result of the mechanical and thermal loading of the jacket tube. To avoid this problem, the utility model proposes to provide stiffening elements in the jacket tube, which are formed as external beads. In the case of non-cylindrical shapes of the housing, they counteract unwanted distortion of the cross section.

The DE 40 01 419 C1 discloses a catalyst housing in which at least in a portion of a central portion wholly or partially internal beads and outer beads are introduced, wherein a distance of the inner beads is greater than their double radius and about equal to or smaller than four times their radius. In addition, the catalyst housing has stiffening longitudinal beads.

On this basis, it is first object of the invention to provide an exhaust gas purification component whose housing has an improved property with regard to at least one of the aforementioned requirements. In particular, the manufacture or provision of exhaust gas cleaning components of various kinds is to be made possible by cost-effective aspects by measures are taken, for example, allow a reduced use of materials at least constant stability with respect to the housing.

These objects are achieved by an exhaust gas purification component with the features of claim 1. Further advantageous embodiments of the invention are described in the dependent claims. It should be noted that the features listed individually in the claims can be combined in any meaningful way with each other, regardless of the currently considered advantageous combination of features.

The exhaust gas purification component according to the invention comprises at least one body and at least one housing which at least partially encloses the at least one body. The exhaust gas purification component is characterized in that at least one housing is provided with superimposed stiffening structures, wherein the stiffening structures are formed only radially outward and wherein the at least one body and the at least one housing are joined together by joining technology.

First, it should be made clear that the housing proposed here is advantageous for all known exhaust gas cleaning components. In particular, all exhaust gas cleaning components that are used in the exhaust gas line of an exhaust system of mobile internal combustion engines (eg gasoline engines, diesel engines or other engines) are to be subsumed under exhaust gas cleaning components. By way of example, catalyst carrier bodies, adsorbers, particle traps, soot filters, flow mixers, etc. may be mentioned here. The housing is thereby essentially directly or indirectly a contact with the exhaust pipe. The function of the exhaust gas purification component is therefore superficially determined by the body, which has a shape tailored to its function. The housing is therefore a kind of framework or framework for the Body and ensures the permanent preservation of the body or the exhaust gas cleaning component even under high thermal and dynamic loads.

The housing is now provided according to the invention with superimposed "stiffening structures. This means that at least two, preferably a plurality or plurality of stiffening structures are provided in or on the housing. However, these do not run, as in the known arrangements, substantially parallel to each other. On the contrary, at least one, preferably a plurality of stiffening structures touch each other, cross each other, merge into one another and / or pass over one another. This forms a kind of nodes, connection areas or the like. Due to the fact that such stiffening structures usually inherent in the property along their direction of extension increased resistance torque or increased stiffness, and the plurality of stiffening directions to form nodes or connecting areas in different directions (ie, not only parallel to each other) are oriented is the housing is particularly robust and dimensionally stable. This also has the consequence, for example, that the outer shape of the housing is virtually unchanged even after a large number of different thermal cycling stresses. The provision of such superimposed stiffening structures opens up a large number of creative possibilities for reducing the cost of producing such exhaust gas purification components. The exhaust gas cleaning components can be designed larger volume while maintaining the wall thickness of the housing, but it is also possible, for example, to reduce the wall thickness and thus material costs and leave the body substantially unchanged. In addition, an increased lifetime of the exhaust gas cleaning components is to be expected.

The at least one body and the at least one housing are joined together by joining technology. For this purpose, in particular the joining techniques soldering and / or welding are suitable. The material bond takes place, possibly using a filler material, close to the contact area of body and housing. In principle, it is also possible that the material connection is at least partially formed by direct diffusion connections of body and housing.

According to one embodiment of the invention, the stiffening structures at least partially intersect each other. In other words, for example, a number of stiffening structures (one or more) intersect other stiffening structures. If necessary, stiffening structures are provided which do not overlap with other stiffening structures. But it is also possible that (only) a partial section or a partial region of the stiffening structures intersect with one another. In this way, different areas of the housing can be formed, wherein in one area there is an increased rigidity in relation to other areas of the housing. The variety of variations with regard to the arrangement or orientations of the stiffening structures allows a different, tailored to the application, thermal and mechanical behavior of the housing.

It is further proposed that the stiffening structures at least partially form a regular pattern. This means, on the one hand, that the stiffening structures partly form a pattern with each other, but possibly also have areas which do not form a pattern. Likewise, this also means that a plurality of stiffening structures are part of the regular pattern over their entire length, but only a certain number of such stiffening structures form the regular pattern. By pattern is meant in particular an arrangement of the stiffening structures, in which housing areas are generated, which are enclosed by a kind of frame ", this frame" being formed by the stiffening structures and nodal points. However, the stiffening structures can also be arranged such that a single one forms such a frame, then not necessarily node points but possibly corner points are formed.

Basically, with regard to the configuration of the stiffening structures or their arrangement in the housing no specification, but is advantageous such a configuration in which the stiffening structures essentially represent the shortest connection from one node to another or the next node. If a large number of such housing areas occur, each of which is surrounded by a similar frame (for example with regard to the surface area, the shape, etc.), this is understood to mean a regular pattern. The provision of a regular pattern has advantages in terms of transporting such exhaust gas purification components as well as the formation of permanent connections later with the exhaust gas conduit. In addition, a uniform force transmission through the housing is favored.

In this context, it is particularly advantageous if the regular pattern is designed as a lattice structure or honeycomb structure. A lattice structure is understood to mean that a substantially square, diamond-like or rectangular housing area is framed by the stiffening structures. In a honeycomb structure, more than four stiffening structures are used to form the frame, in particular six or eight.

In the formation of patterns is basically still noted that different patterns may optionally overlap or that in different areas of the housing different patterns can be provided. Also, the patterns may be more complex in nature, for example by combining different honeycomb structures.

According to a further embodiment of the exhaust gas purification component, at least a part of the stiffening structures comprise inclusions. This means in particular that these deposits are connected via a material bond with the stiffening structure (eg diffusion, soldering, welding). It is not necessarily required that the stiffening structures enclose the deposits completely, but the storage can also be part of the surface of the housing. The inclusion, which may extend entirely over a stiffening structure or only a portion, allows additional, precise adjustment of the desired properties of the housing. These deposits can for example be made of a different material than the housing, so that in turn the mechanical and the thermal behavior of the housing can be influenced in this way.

Furthermore, it is also proposed that the at least one housing is made of a heat-resistant metal and has a wall thickness which is in the range of 1.0 mm to 0.3 mm, preferably in the range of 0.75 mm to 0.3 mm, and in particular in the range of 0.5 mm to 0.3 mm. Currently operating "casings for exhaust gas purification components in the exhaust system of an automobile have a wall thickness of about 2 mm. There are special designs of casing pipes, which have a wall thickness, which is also below. However, special materials and / or constructions, such as z. B. initially with reference to the EP 0 799 369 B1 were used. The providence of superimposed stiffening structures in or on the housing, however, allows a reduction of the wall thickness even with normal "metallic housings.

Especially with the particularly thin running packages, z. For example, with a wall thickness in the range of 0.5 mm to 0.3 mm, if necessary, make sure that the construction is still weldable to ensure a permanent connection with the exhaust system. For this purpose, it may be advantageous to reinforce areas of the housing. This means, for example, that the front side of the housing has a kind of flanging, fold, etc., so that a reinforcement is achieved by material doubling. It is also possible to use so-called tailored blanks, which are designed with different wall thicknesses.

According to yet another embodiment of the exhaust gas purification component, two housings are provided, wherein the housings are arranged substantially concentric to each other and at least the inner housing is provided with superimposed stiffening structures. Such a design of a double jacket "is intended in particular for applications with extreme thermal and / or dynamic stress. In addition, such an embodiment of the exhaust gas purification component may be advantageous if special heat insulation properties of the housing are required. This may be necessary in particular in connection with the configuration of the body as a catalyst carrier body or adsorber.

According to a further embodiment of the exhaust gas purification component, the at least one body is constructed of at least partially structured sheet-metal foils, so that channels through which the exhaust gas can flow are formed. Most preferably, the at least one body is designed as a metallic honeycomb body. The embodiments of such structured sheet metal foils is explained below with reference to metallic honeycomb body and can be easily transferred to other embodiments of the body.

One differentiates above all two typical designs for metallic honeycomb bodies. An early design for which the DE 29 02 779 A1 typical examples shows is the spiral design, in which substantially a smooth and a corrugated sheet metal layer or foil sheet are superimposed and spirally wound. In another design, the honeycomb body is constructed of a plurality of alternately arranged smooth and corrugated or differently corrugated sheet metal layers, wherein the sheet metal layers initially form one or more stacks, which are entwined with each other. The ends of all sheet metal layers come to lie outside and can be connected to a housing or casing tube, whereby numerous compounds that increase the durability of the honeycomb body arise. Typical examples of these designs are in EP 0 245 737 B1 or the WO 90/03 220 A1 described. It has also long been known to provide the sheet metal layers with additional structures in order to influence the flow and / or to achieve cross-mixing between the individual flow channels (cf. WO 91/01 178 A1 ). Finally, there are also honeycomb bodies in conical design, optionally also with additional additional structures for flow control. Such a honeycomb body is for example in the WO 97/49905 A1 described. All of the above documents may be used to illustrate and supplement the description of the removal of metallic honeycomb bodies.

Especially in the embodiment of the exhaust gas cleaning component with at least partially structured sheet metal foils, it is advantageous that the metal foil at least partially abut there on the housing where no stiffening structure is provided. The stiffening structures, which may face both inwardly towards the body and outwardly in opposite directions, typically result in irregularities in the surface or inner surface of the housing. These unevenness can be recognized, for example, as beading, indentation, etc. But this also means that starting from the center of the exhaust gas purification component, the housing does not have the same distance everywhere. In the embodiment of the body with sheet metal layers, which form at least partially with its two ends the peripheral surface of the body and thus the connection to the housing, it is advantageous for the formation of permanent joining technical connections of the body and housing, that these ends of the metal foils over a possible large area on the housing. If now a stiffening structure run parallel to the end of such a sheet metal foil, there is a risk that this metal foil does not have sufficient contact with the housing and thus only insufficient joining technology connections can subsequently be generated. Therefore, it is proposed here that the metal foils, or their ends, in turn superimposed on the stiffening structure to ensure that there is sufficient contact.

• – Oxidieren von Abgasbestandteilen;
• – Reduzieren von Abgasbestandteilen;
• – Adsorbieren von Abgasbestandteilen;
• – Einlagern von Abgasbestandteilen.

According to a further embodiment of the exhaust gas purification component, the at least one body at least partially has a coating which has at least one of the following functions:

• - Oxidizing exhaust components;
• - reducing exhaust components;
• - Adsorbing exhaust components;
• - Storage of exhaust components.

With regard to the exhaust gas constituents, in particular unsaturated hydrocarbons, nitrogen dioxides, particles, water and oxygen are to be emphasized. In this case, special redox systems are preferably formed so that the pollutants contained in the exhaust gas are converted with high efficiency into far less harmful or easily removable components.

In addition, an exhaust system of a mobile internal combustion engine with at least one exhaust pipe is proposed, which comprises at least one exhaust gas purification component according to the invention, as described above.

The invention and the technical environment will be explained in more detail with reference to FIGS. The figures show particularly preferred embodiments of the invention, to which the invention is not limited. Show it:

1 a detailed perspective view of a first embodiment of the exhaust gas purification component;

2 schematically two embodiments of a regular pattern of overlapping reinforcing structures;

3 schematically and in perspective an automobile with a Abgasanalge comprising a plurality of exhaust gas purification components;

4 a weitre embodiment of the emission control component according to the invention with two housings.

The 1 shows schematically and in an enlarged detail an embodiment of an inventive exhaust gas component 1 , The exhaust gas purification component 1 includes a body 2 and a housing 3 which the body 2 encloses. The housing 3 is with a variety of overlapping stiffening structures 5 Mistake. The stiffening structures 5 form nodes 26 , The housing 3 here has a uniform wall thickness 8th on, so the stiffening structures 5 are formed as protuberances, beads or the like radially outward, so from the body 2 extend away. It is also possible that the wall thickness 8th at least partially in the area of the reinforcing structure 5 varies, for example, gets bigger. This applies in particular to the area in or near the junction 26 ,

The body 2 is formed of a plurality of sheet metal foils. This is the body 2 as a honeycomb body with a plurality of channels 11 educated. The channels 11 be through smooth tin foils 9 and structured sheet metal foils 10 educated. The metal foils are covered with a coating 12 Mistake.

2 shows two possible embodiments of regular patterns 6 as with a plurality of stiffening structures 5 can be formed. Under a) a grid structure is shown on or in the housing 3 by a corresponding arrangement of several stiffening structures 5 is formed.

Sections of the stiffening structures 5 as well as the nodes 26 close to the superposition of at least two stiffening structures 5 arise, each limiting a housing area 25 enclosing, so that a kind of frame is formed. In the grid structure is this housing area 25 or their projection in a plane square or rectangular. With b) a honeycomb structure is a regular pattern 6 shown. Again, each is a housing area 25 through sections of the reinforcing structures 5 as well as the nodes 26 limited, so that here also a kind of frame is formed, which is a particularly dimensionally rigid embodiment of the housing 3 have as a consequence. A reinforcing structure 5 can in the formation of a pattern 6 basically several housing areas 25 at least partially limit.

3 shows schematically and in perspective an automobile 15 with an exhaust system 13 , Depending on the engine control 16 becomes the internal combustion engine 17 operated, so that due to the combustion processes taking place there exhaust gas through the exhaust pipe 14 passed through and finally delivered to the environment. For purifying the exhaust gas are a plurality of exhaust gas purification components 1 provided here, for example, in the flow direction sequentially first followed by a catalyst 18 , connect a particle filter 19 and finally an adsorber 20 flows through the exhaust gas. The exhaust system 13 However, it is combinable or expandable with any other known combination or component for purifying exhaust gas. Finally, the purified exhaust gas is still a muffler 21 supplied, the continuing in the exhaust system pressure surges due to the intermittent combustion in the internal combustion engine 17 attenuates.

4 shows a further embodiment of an emission control component according to the invention 1 , This emission control component 1 has a body 2 the one with an inner housing 3 in contact, which itself from an outer housing 4 is enclosed. The inner housing 3 and the outer case 4 are arranged substantially concentric with each other. The inner housing 3 is with overlapping stiffening structures 5 Mistake. Here are the stiffening structures 5 arranged so that along the flow direction 24 flowing exhaust does not affect the body 2 can flow past.

The body 2 is formed in the illustrated embodiment as a particle trap and has structured sheet metal foils 10 and at least one filter layer 22 (eg comprising metallic fibers). The at least part of the structured sheet metal foils 10 at least has a lead 23 that at least partially into a channel 11 protrudes and thus a deflection of partial exhaust gas streams of adjacent, arranged separate channels 11 through the at least one filter layer 22 provoked through. When penetrating the filter layers 22 In particular, ash and soot are deposited, which are at least partially intermittently or continuously converted into gaseous constituents.

The invention proposed here allows widespread use in the automotive industry and, especially with regard to mass production, allows significant cost-saving potentials in the production of exhaust gas purification components. At the same time, no compromises have to be made to the structural integrity of the exhaust gas purification components. Thus, relatively thin, lightweight housing can be used, while maintaining the required roundness and stability requirements are met.

LIST OF REFERENCE NUMBERS

1

emission control component

2

body

3

Inner housing

4

Outer case

5

stiffening structure

6

template

7

warehousing

8th

Wall thickness

9

Smooth sheet metal foil

10

Structured sheet metal foil

11

channel

12

coating

13

exhaust system

14

exhaust pipe

15

automobile

16

motor control

17

Internal combustion engine

18

catalyst

19

particulate Filter

20

adsorber

21

silencer

22

filter layer

23

head Start

24

flow direction

25

housing area

26

junction

Claims (12)

Exhaust gas purification component ( 1 ) comprising at least one body ( 2 ) and at least one housing ( 3 . 4 ) containing the at least one body ( 2 ) at least partially encloses, characterized in that the at least one housing ( 3 . 4 ) with overlapping stiffening structures ( 5 ), wherein the stiffening structures ( 5 ) are formed only radially outward and wherein the at least one body ( 2 ) and the at least one housing ( 3 . 4 ) are connected to one another by joining technology. Exhaust gas purification component ( 1 ) according to claim 1, characterized in that the stiffening structures ( 5 ) at least partially intersect each other. Exhaust gas purification component ( 1 ) according to claim 1 or 2, characterized in that the stiffening structures ( 5 ) at least partially a regular pattern ( 6 ) form. Exhaust gas purification component ( 1 ) according to claim 3, characterized in that the regular pattern ( 6 ) is a lattice structure or honeycomb structure. Exhaust gas purification component ( 1 ) according to claim 3, characterized in that the stiffening structures ( 5 ) and nodes ( 26 ) of the stiffening structures ( 5 ) Frame, wherein the frame housing areas ( 25 ) and wherein the housing areas ( 25 ) free of stiffening structures ( 5 ) are. Exhaust gas purification component ( 1 ) according to one of the preceding claims, characterized in that at least part of the stiffening structures ( 5 ) Storages ( 7 ). Exhaust gas purification component ( 1 ) according to one of the preceding claims, characterized in that the at least one housing ( 3 . 4 ) is made of a heat-resistant metal and a wall thickness ( 8th ), which is in the range of 1 millimeter to 0.3 millimeters, preferably in the range of 0.75 millimeters to 0.3 millimeters. Exhaust gas purification component ( 1 ) according to one of the preceding claims, characterized in that two housings ( 3 . 4 ) are provided, wherein the housing ( 3 . 4 ) are arranged substantially concentrically with each other and at least the inner housing ( 3 ) with overlapping stiffening structures ( 5 ) is provided. Exhaust gas purification component ( 1 ) according to one of the preceding claims, characterized in that the at least one body ( 2 ) of at least partially structured sheet metal foils ( 9 . 10 ) is constructed so that for the exhaust gas flow-through channels ( 11 ) are formed. Exhaust gas purification component ( 1 ) according to claim 8, characterized in that the sheet metal foils ( 9 . 10 ) at least partially there on the housing ( 3 . 4 ), where no stiffening structure ( 5 ) is provided. Exhaust gas purification component ( 1 ) according to one of the preceding claims, characterized in that the at least one body ( 2 ) at least partially a coating ( 12 ) having at least one of the following functions: - oxidizing exhaust components, - reducing exhaust components, - adsorbing exhaust components, - storing exhaust components. Exhaust system ( 13 ) a mobile internal combustion engine with at least one exhaust pipe ( 14 ) comprise at least one exhaust gas purification component ( 1 ) according to any one of the preceding claims.

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