EP0992659A2 - Exhaust pipe element and method for producing an exhaust pipe element - Google Patents

Abstract

The exhaust guide element has two or more feed pipes (15) connected to an IC engine (1). The element wall consists of two wall elements (23,24) each with two metallic shells (25,26) and an intermediate layer of heat insulating material. The wall elements have connected edge sections and together enclose interior spaces of all feed pipes. The heat insulating material is micro-porous, has a granulated structure, and is at least 3mm thick.

Description

The invention relates to an exhaust gas guide element or Exhaust device with at least two feed lines to the Connect to an internal combustion engine and a wall.

The exhaust guiding element serves as part of an exhaust system an internal combustion engine for directing and possibly for catalytic treatment and cleaning of exhaust gas. At the Internal combustion engine can be, for example Petrol engine of a passenger car or other Trade street motor vehicles.

Known exhaust manifolds have two or more with one Internal combustion engine connectable supply lines and one for these common collective output, the different lines consist of pipes with simple, metallic walls. Such walls are on during the operation of the internal combustion engine high, usually at least about 700 ° C Heated temperatures so that such exhaust manifolds and especially their supply lines give a lot of heat to their surroundings submit. The big one, through radiation, heat conduction and convection emitted heat causes undesirable heating from temperature-sensitive located near the exhaust manifold Parts and / or spaces, such as electrical, electronic and / or plastic components, the fuel tank, a spare wheel and / or the passenger compartment. In practice it is therefore often necessary in the Place heat shields near the exhaust manifold, which make the manufacture of the motor vehicle expensive, a lot of space claim and because of the vibrations generated by the engine Can cause noise problems.

It is also known the gas-carrying parts of an exhaust manifold or catalyst with a double-walled cooling jacket to enclose. The latter has a space through which water is passed during operation. However, such a cooling jacket additionally requires one Cooling system for circulating and cooling the heated in the cooling jacket Water or an enlargement of one primarily for cooling engine cooling system. This increases the space requirement and the cost.

US 3,751,920 A discloses a non-catalytic one Exhaust reactor with a housing and feed lines that run along distributed through the cylindrical housing jacket open into the interior of the housing. This So the exhaust gas reactor does not form an exhaust manifold and generates a large back pressure during operation. The Feed lines of the exhaust gas reactor apparently have metallic ones Walls and give off a lot of heat to the environment. The The coat has an outer wall that is apparently made of metal. This encloses an insulation layer, which the Mouths of the supply lines and the discharge line with holes provided and inside, outside, at the ends and at the holes is provided with coatings. On the inside of the end walls insulation layers are also arranged. This Insulation layers and their coatings have to be added to the metallic, cylindrical outer wall, the metallic, flat end walls and the supply lines manufactured and assembled. For the formation of this Housing, the supply lines and the insulation layers must so many separate parts made and assembled become. For the rest, the materials are the insulation layers and coatings not specified.

FR 2 238 585 A discloses a composite material consisting of a glass fiber fabric arranged between two sheets and in particular to form silencer housings serves. To produce such a two plates of Composite material formed into half-shells and then at edges connected with each other. FR 2 238 585 A discloses no exhaust manifolds. Furthermore, the glass fiber fabric is disclosed only fairly thin and also has only a low compressive strength. For forming a flat, composite material plate to a relatively small radius of curvature of the exhaust manifold however, large pressure forces must be exerted on the plate been exercised, which makes the glass fiber fabric very strong would be squeezed. The thickness of the fiberglass cloth would in the finished exhaust manifold according to tests carried out probably at most about 20% to 35% of the original thickness and only less than about 1 mm be. This could result in the heat emission from an exhaust manifold be reduced insufficiently.

US 4 215 093 A discloses one catalyst and two Supply lines for connecting an internal combustion engine to the Catalyst. The latter has a housing with two walls each of which is composed of two shells and between which there is an air-containing space is. However, the feed lines have only simple, metallic ones Walls that are heated to high temperatures during operation and give off a lot of heat. Also have investigations on Catalytic converters of passenger cars with a similar, double-walled housing shown that the outer wall such housing during operation despite the air containing Intermediate space is heated to high temperatures typically be about 500 ° C to 600 ° C.

Accordingly, such a catalyst also gives a lot Heat to its surroundings. The from US 4 215 093 A known exhaust device also has the disadvantages that assembled many separate parts for their manufacture need to be, thereby producing the exhaust device is more expensive, the connection of the required outer wall-forming shells with screws.

Similar problems can also arise with a separate Exhaust manifold result.

The invention is therefore based on the object Exhaust gas guide element or an exhaust device for guiding and possibly catalytic treatment of exhaust gas to create the or the disadvantages of known exhaust gas guide elements and / or Exhaust devices with an exhaust manifold and / or Fixes catalyst with at least two feed lines and one good insulation results, but still inexpensive can be manufactured and installed and takes up little space claimed.

This object is achieved according to the invention by a Exhaust gas guide element with the features of claim 1 solved.

The invention further relates to a method of manufacture an exhaust gas guide element, the method according to the Invention has the features of claim 14.

Advantageous further developments of the exhaust gas guide element and of the method emerge from the dependent claims.

According to the invention between the shells each Wall element existing layer of heat insulating material results in good thermal insulation. This ensures that the heat supplied by the exhaust gas largely in the exhaust gas and / or inside the exhaust guiding element or the exhaust device remains. The heat remaining in the exhaust gas is from this transported further and at least to a large extent discharged into the environment together with the exhaust gas. Each outer shell of the exhaust gas guide element or Exhaust device is therefore only relative to one in operation warmed to low temperature. There is also the exhaust gas guiding element little heat to its surroundings. It is accordingly also not necessary to be near the exhaust guiding element located, heat-sensitive parts or rooms with heat shields against the radiated or up from the exhaust gas guide other way to protect heat given off.

In an advantageous embodiment of the exhaust gas guide element this has a supply line Exhaust manifold and another one downstream of it arranged, together with this forming a unit Catalytic converter with catalytic means Treatment of exhaust gas on. The two wall elements of the Exhaust manifolds can then, for example, also in cross section still an interior of the catalyst and in particular the Fully enclose catalyst medium. Instead can use two additional wall elements for the catalyst are provided, each of which is two metallic shells and a layer of thermal insulation arranged between them Has material. The two additional wall elements can then together in cross section the catalyst agents completely enclose and for example directly, immediate, rigid and tight with those to the exhaust manifold belonging wall elements to be connected. Through this The formation of the exhaust gas guide element also becomes the catalytic converter and its connection to the exhaust manifold very well thermally insulated. Furthermore, such a unit particularly economical to manufacture.

The wall elements are preferably so firm and essentially rigid and essentially such rigid and at least approximately or completely tight connected that they are self-supporting and together form a self-supporting part of the wall. At least a substantial part of the wall of the Exhaust gas guide can then exclusively from the interconnected wall elements exist. The wall then, for example, at most at the entrance and / or at the exit of the flue gas guide element with connection and / or Lanyards are provided to the exhaust guiding element with the internal combustion engine and a downstream of Exhaust gas guide arranged part of the exhaust system connect. The connection and / or connection means can for example one common for all supply lines Connection flange or at least two connection flanges have assigned to different supply lines. Furthermore, the wall elements can then be at least the largest Part of the wall is the outermost boundary of the exhaust gas guiding element form.

The wall elements can be designed in this way and with one another connected that they take up little space. The shells are for example about 0.5 mm to 1 mm thick. The heat-insulating layer is in the finished exhaust gas guide element preferably generally at most 10 mm, preferably essentially at least 2 mm and for example at least about 3 mm to at most 5 mm thick. The Temperatures of the outer shells of the wall elements are then for example at most about 50% of that from 0 ° C measured temperature of the exhaust gas and / or the temperatures, which is on the outer surface of a simple metallic Wall with otherwise identical design of the exhaust gas guide element or would result in the exhaust device.

The heat insulating material is preferred inorganic, non-flammable and at least up to the operating temperature the exhaust control element and the temperature of the Exhaust gas, for example up to at least 800 ° C, heat-resistant. Each The insulation material layer consists, for example, of a coherent, reasonably solid, especially also fairly pressure-resistant, microporous plate and / or foils. By "microporous" it is meant that the layer or Plate pores with sizes of approximately 1 µm or a few, however has less than 10 µm or less than 1 µm. Any thermal insulation Layer is original, for example Particulate material formed at least for Most of the grains may still have been fibers and by pressing and thermal treatment and / or a chemical reaction has solidified. Each such layer therefore has more or more, for example less tightly adhering grains and possibly still fibers used for reinforcement. The fiber content is for example at most about 10% by weight so that the layer or plate at least in large part and for example for the most part has a granular structure. The insulation material and especially its granular components for example essentially from oxidic substances. The Insulating material contains, for example, silica and / or at least one silicate and / or oxide ceramic, namely preferably at least 50% by weight of highly disperse silica. The For example, fibers consist of a mineral and / or oxide ceramic material. Such microporous insulating materials are for example in EP 0 029 227 A and corresponding US 4,985,163 A and described for example under the brand name WACKER WDS from Wacker-Chemie GmbH, Munich, Federal Republic of Germany.

To produce the wall for each or each Wall element to form two original flat sheet metal parts reshaped and connected. The two sheet metal parts used to form a pair of shells at least for a large part of the forming process in pairs together with a layer arranged between them are formed from heat-insulating material. this makes possible an economical production of the wall.

Forming can be done, for example, by deep drawing. During the forming process, considerable pressure is exerted on the Sheet metal parts or shells and the one arranged between them Layer of thermal insulation material exercised. The heat insulating Layer is pressed together. If that Insulating material made from a pre-consolidated, microporous Plate or film is made, the thickness of the thermal insulation Layer when forming, for example, less than 50%, namely typically about 20% to 40% smaller. The The thickness of the layer therefore only has to be proportional before the forming be less than the finished exhaust gas guide.

Possibly each heat-insulating layer instead of one microporous plate or film at least for the most part from a fiber material, for example a single-ply or multilayered fabric. The fibers can for example made of oxide ceramics and / or rock wool, basalt wool, glass wool and / or any other mineral material. However, fiber material becomes essential when forming more compressed than a pre-consolidated, microporous plate or foil, so the thickness when forming for example decreases about 65% to 80%.

Fig. 1 eine schematische Schrägansicht eines Verbrennungsmotors mit einem Abgasleitelement, das einen Auspuffkrümmer und einen Katalysator aufweist,

Fig. 2 das teils im Längsschnitt und teils in Seitenansicht dargestellte Abgasleitelement,

Fig. 3 einen Querschnitt durch einen Bereich des Katalysators entlang der Linie III-III der Fig. 2 in grösserem Massstab,

Fig. 4 einen Querschnitt durch das Abgaselement entlang der Linie IV-IV der Fig. 2 in grösserem Massstab,

Fig. 5 einen Querschnitt durch zwei Blechteile, die zur Bildung der zwei sich in den Figuren 3, 4 unten befindenden Schalen des Abgasleitelements dienen, und eine schematisch dargestellte Umformvorrichtung zum Umformen der Blechteile,

Fig. 6 einen Querschnitt durch einen Bereich der beiden in Fig. 5 gezeichneten Blechteile bzw. Schalen nach der teilweisen Umformung von diesen und eine schematisch dargestellte Schneidvorrichtung,

Fig. 7 eine Schneidvorrichtung zum Wegschneiden von Bereichen von Blechteilen, die zur Bildung der sich in den Figuren 3, 4 oben befindenden Schalen bestimmt sind,

Fig. 8 einen Längsschnitt durch einen Bereich eines anderen Abgasleitelements,

Fig. 9 eine Schrägansicht von Teilen eines anderen Abgasleitelements, wobei die wärmedämmende Wandung weggelassen wurde,

Fig. 10 einen vereinfachten Längsschnitt durch das Abgasleitelement gemäss der Fig. 9 mit der wärmedämmenden Wandung und

Fig. 11 eine Schrägansicht eines Abgasleitelements, das nur einen Auspuffkrümmer aufweist.

The object of the invention is subsequently explained in more detail with reference to exemplary embodiments shown in the drawing. In the drawing shows

1 is a schematic oblique view of an internal combustion engine with an exhaust gas guide element which has an exhaust manifold and a catalytic converter,

2 shows the exhaust gas guide element, shown partly in longitudinal section and partly in side view,

3 shows a cross section through an area of the catalyst along the line III-III of FIG. 2 on a larger scale,

4 shows a cross section through the exhaust gas element along the line IV-IV of FIG. 2 on a larger scale,

5 shows a cross section through two sheet metal parts which are used to form the two shells of the exhaust gas guide element located at the bottom in FIGS. 3 and 4, and a schematically illustrated shaping device for shaping the sheet metal parts,

6 shows a cross section through a region of the two sheet metal parts or shells shown in FIG. 5 after the partial shaping thereof and a schematically illustrated cutting device,

7 shows a cutting device for cutting away areas of sheet metal parts which are intended to form the shells located at the top in FIGS. 3, 4,

8 shows a longitudinal section through a region of another exhaust gas guide element,

9 is an oblique view of parts of another exhaust gas guide element, wherein the heat-insulating wall has been omitted,

FIG. 10 shows a simplified longitudinal section through the exhaust gas guide element according to FIG. 9 with the heat-insulating wall and

11 is an oblique view of an exhaust gas guide element which has only one exhaust manifold.

The partially drawn schematically in Figures 1 and 2 Gasoline internal combustion engine 1 has a motor housing 2, several cylinders and at least two exhaust ports 3 each an opening. Each exhaust outlet 3 defines one straight Axis 4. For example, the engine has three on both sides Exhaust gas outlets 3, the axes 4 of which are parallel to one another, for example, in a common plane and from the motor housing tilted away downwards.

An exhaust system has one that can be seen in FIGS. 1 to 4 Exhaust device 11 or an exhaust gas guide element 11 on. The exhaust device or the exhaust guiding element 11 forms an exhaust manifold 12 and a catalytic converter 13. The exhaust manifold 12 has at least two, namely three in theirs Longitudinal directions at least partially and partially curved Supply lines 15 for connecting the exhaust gas outlets 3 to the catalytic converter 13. The exhaust manifold 12 has connection and / or Lanyard with a common for all leads 15 Connection flange 17 on. This has for each supply line 15 an opening.

The catalytic converter 13 has a housing 21 the flow direction of the exhaust gas in turn an input section 21a, a main section 21b, an exit section 21c and a collar 21d. The main section 21b is essentially parallel to one that he defines, straight axis 22 and generally cylindrical and in Cross-section, for example, generally approximately oval and / or elliptical. The input section 21a connects the three leads 15 with the main section 21b and expanded for example in at least one longitudinal section Main section 21b. The output section 21c is generally funnel-shaped and tapers from the central section 21b away. The collar 21d defines a circular opening. The axis 22 forms with the axes 4 parallel to one another for example an obtuse angle α.

The exhaust manifold 12 and the housing 21 of the catalyst 13 have a common wall with two along the flow path connected, heat-insulating multi-layer and / or composite wall elements 23, 24. Each wall element 23, 24 forms approximately half of the wall in cross section and has a main section that is seamlessly connected in cross-section, about half the wall of the case and a portion of the end portions connected to the housing 21 the leads 15 forms. Every wall element has further three from its main section to the connecting flange 17 extending finger-shaped sections, which in Cross section separated by free spaces and each one of the supply lines 15 are assigned. The two Wall elements enclose one in cross sections Interior completely.

Each multilayer and / or composite wall element 23, 24 has a pair of metallic, steel, one-piece shells, namely an outer shell 25 or 27 and an inner shell 26 and 28 respectively. The two at the same Shells 25, 26 and 27, 28 belonging to the wall element have through a space separated middle sections 25a, 26a, 27a, 28a and each other along the entire circumference of the shell touching edge sections. The from the entrances of the Leads 15 generally along the length the flow path of the exhaust gas to the outlet of the catalyst extending outer edge sections of the four shells 25, 26, 27, 28 are in Figures 3, 4 with 25b, 26b, 27b, 28b designated. The middle sections 25a, 26a, 27a, 28a are in Cross-section arched and curved at least in places. At the two shells located in Figures 3, 4 below 27, 28 the edge sections 27b, 28b protrude from the central sections 27a, 28a away to the outside are in cross section approximately angular and / or linear. The Edge sections 25b, 26b of the two in FIGS. 3, 4 above shells 25 and 26 are opposite Central section 25a or 26a at most slightly bent and protrude into that of the edge portions 28b of the lower, inner Shells 28 formed throats into it. The edge portions 25b the upper, outer shell 25 touch the edge portions 28b of the lower, inner shell 28. Each finger-shaped Section of a shell is shaped analogously in cross section the sections of the shells belonging to the housing. Both Inputs of the leads 15 and at the exit of the Catalyst touch the edge sections of the same Shells belonging to each other in the wall element in the in Fig. 2nd obvious ways. The edge sections of the different Shells lie against each other at the points of contact, whereby at least two edge sections each directly touch. The edge sections of the same wall element belonging shells are along the entire circumference of the Shells firm, essentially rigid, as well as insoluble and dense connected with each other and partly with other parts, namely welded. In the general in the 3, 4 shown in the longitudinal direction Edge sections 25b, 26, 27b, 28b are all four each other edge portions 25b, 26b, 27b, 28b touching in pairs creates a joint in a single welding process Welded connection 33 connected to each other. Corresponding applies to the edge sections between the finger-shaped Sections of the shells.

The space between the middle sections 25a, 26a the shells 25 and 26 contain an insulating material layer 35. The space between the middle sections 27a, 28a of the two shells 27 and 28 contains an insulating material layer 36. The insulating material layers 35, 36 fill the mentioned gaps essentially completely. The Insulation material can be made from any of the in the introduction Insulating materials described, for example one microporous plate or film.

The main portion 21b of the housing 21 contains Catalyst means 41 for catalytic treatment and Exhaust gas cleaning. The catalyst means 41 have for example an approximately oval in cross-section and / or elliptical, essentially cylindrical catalyst body 42 with an exhaust gas entry surface 42a and one Exhaust gas outlet area 42b. The surfaces 42a, 42b are flat and perpendicular to axis 22. The catalyst body has for example, a ceramic substrate with a variety of axial passages for the exhaust gas. The passages delimiting surfaces of the substrate are covered with coatings provided, which are largely made of porous aluminum oxide exist and also at least one catalytically active Have material such as platinum and iridium.

The main portion 21b of the housing 21 further includes a heat-resistant intermediate layer 43 which between the Shell surface of the catalyst body 42 and the inner surface the inner wall 32 is arranged, the catalyst body in Cross-section encloses and holds vibration-damping. The Liner 43 consists of at least one Operating temperature of the catalyst means heat-resistant, heat-insulating and, for example, elastically deformable, in particular radially compressible, layered Material. The intermediate layer 43 consists, for example, of a Mat with inorganic fibers, mineral flakes, the be bloated when heated the first time, and one Binder. The liner could, however, at least a layer of wire mesh or wire mesh and a have heat-insulating filler.

The one formed by the two wall elements 23, 24 The wall also encloses a funnel-shaped cross section Collection and / or entrance inner wall 45. This is at Transition from the exhaust manifold to the catalytic converter arranged and is mostly within the entrance section 21a of the housing, but also projects into the Exhaust manifold belonging area of the interior of the Exhaust control element. The collection and / or entrance inner wall 45 encloses a collecting interior in cross section. The downstream end portion of the exhaust manifold and the transition section from this to The catalyst thus forms a collector or collecting section of the exhaust guiding element. The collection and / or entrance inner wall 45 is located along the flow path closer to the Connecting flange 17 end having an end portion an entry opening which is particularly clearly visible in FIG. 4 45a, a widening in the flow direction Middle section and at its downstream End of a short, essentially cylindrical, in cross section approximately oval and / or elliptical end section with an outlet opening. This end section extends up to at least approximately to the exhaust gas inlet surface of the Catalyst body 42, has at least approximately with the Shell or peripheral surface of the catalyst body aligned Outside surface and is at least partially from the liner 43 enclosed. The collection and / or entrance inner wall 45 consists of two shells 46, 47 made of a metallic Material, namely steel. The shells 46, 47 are in cross section arched and curved in places and nearby their edges welded together.

Each supply line 15 has an inner line 51. This exists from a one-piece, at least partially curved Pipe made of a metallic material, namely steel. The Connection flange 17 has, for example, two planes, one against the other adjacent panels. The assigned to the supply lines Finger-shaped sections of the four shells 25 to 28 have in Openings of the connecting flange 17 protruding edge sections and are close together with the two of them Flange plates and with entry end sections the inner pipes are welded. The connecting flange 17 is with fasteners 53, for example screws have, releasably attached to the motor housing 2 and connects the inputs of the supply lines are tight with the exhaust gas outlets 3 of the internal combustion engine. The facing away from the flange 17 Exit end portions of the inner leads 51 protrude side by side with the highest small game in the Inlet opening 45a of the collecting and / or entrance inner wall 45, so that they together the inlet opening 45a Fill in the cross-section at least approximately, for example in their longitudinal direction with respect to the collecting and / or entrance inner wall 45 are displaceable and at least approximately tight connection of the inner lines 51 of the feed lines 15 result with the collecting and / or input inner wall 45.

A generally funnel-shaped exit inner wall 55 is downstream of the catalyst means 41 in the housing 27 arranged and is largely in the exit section 21c of the housing 21. The output inner wall 55 has one at its upstream end short, approximately oval and / or elliptical in cross section End section that is at least approximately close to the catalyst body 42 connects, approximately with its jacket and / or Has circumferential surface fleeing outer surface and at least to Part of the intermediate layer 43 is enclosed. On this cylindrical one End section closes a tapered middle section to which a short, approximately cylindrical End section follows, which extends approximately to the downstream arranged end of the housing 21 extends, a circular Opening limited and together with the collar 21d of the housing 21 the exhaust gas outlet common to all supply lines of the catalyst forms. The exit inner wall 55 is made from a one-piece body made of a metallic material, namely steel. One from a tube from a metallic Material, namely steel, is existing lead 57 tight and tight with the output inner wall 55 and through Edge sections of the shells 25, 26, 27, 28 formed collar 21d of the housing 21 connected, namely welded. A metallic, bush 59 made of steel has an axial, through hole with an internal thread, protrudes Holes located upstream of the catalyst means 41 the shells 25, 26 and 46 through and is tight with welded these shells. A lambda probe 60 is in that Internal thread of the bush 59 screwed in and protrudes through it through into the one enclosed by the input inner wall 45 Interior area. A socket 61 is downstream of the catalyst means 41 are welded into a hole in the line 57 and also has an axial through hole an internal thread into which one projects into the lead 57 Lambda probe 67 is screwed in. The exit of the catalyst 13 can via the lead 57 with other parts an exhaust system, in particular with at least one silencer get connected.

The collecting and / or input inner wall 45 is through the Bushing 59 rigidly connected to the composite wall 22 and for example, additionally by at least one bead or the like centered and kept limited mobility or possibly rigid with additional connecting means the composite wall elements 23, 24 connected. The inner lines 51 of the leads 15 are from the inner shells 26, 28 of the composite wall elements 23, 24 essentially and for the most part - i.e. apart from their with that End sections connected by a connecting flange contiguous space 65 separated. The gap 65 also separates most of the funnel-shaped collection and / or inner entrance wall 45 of the composite wall elements 23, 24. The funnel-shaped inner wall 55 is in essentially and for the most part through a space 67 separated from the wall elements 23, 24. The gaps 65, 67 are essentially hollow and contain air and / or at least approximately stationary exhaust gas.

In the manufacture of the exhaust device or the exhaust guiding element 11 are used to form the shells 25, 26, 27, 28, 46, 47 and the outlet inner wall 55 certain, flat, cut one-piece sheet metal parts, for example punched out. Further processing to form the two 3 and 4 shells 27, 28 located at the bottom Serving sheet metal parts will be closer with reference to Figures 5 and 6 explained. The sheet metal parts and their sections are with the the same reference numbers as the finished shells and their sections. In further processing, for example the sheet metal part used to form the outer shell 27 by pre-forming with a shallow recess provided, in which the still flat insulating material layer 36th is inserted. Then the still flat sheet metal part 28 on the Sheet metal part 27 placed and together with the latter in the Forming device 71 shown schematically in FIG. This is designed as a deep-drawing device and has, for example, a fixed one designed as a matrix Forming tool 72, a holding member 73 and an adjustable Molding tool 74, i.e. a stamp. The edge sections 27b, 28b of the two sheet metal parts 27 and 28 are used for forming between the mold 72 and held the holding member 73. If that serves as a stamp Forming tool 74 in the manner arranged by arrows is shifted downwards, the to form the shells 27, 28 serving sheet metal parts and the arranged between them Insulating material layer 36 is simultaneously deformed by deep drawing. The sheet metal parts are plastically deformed and bent. The insulating material layer 36 becomes - dependent on their training - also more or less plastic deformed, bent and also compressed.

The middle sections 27a, 28a of the two sheet metal parts or Shells 27, 28 are obtained during forming, i.e. Thermoforming that drawn in Fig. 6, desired for the finished shells To form. A cutting device shown schematically in FIG. 6 75 has two cutting tools 76, 77, one of which for example the tool 76 a fixed cutting edge and the tool 77 is designed as a movable knife 77 is. After molding the middle sections 27a, 28a the areas of the edge sections 27b that are not required, 28b cut away with the cutting device 75. After that the remaining edge sections 27b, 28b in an additional Forming step angled upwards together or bent so that they get their final shape.

The originally flat sheet metal parts to form the two shells 25, 26 located at the top in FIGS. 3, 4 are reshaped analogously, as is shown in FIG. 5 for the Shells 27, 28 has been described. Sheet metal parts for education the shells 25, 26 are in particular also to a large extent together with that arranged between them Formed insulating material layer 35. After that the one held by the die and the holding member during deep drawing Edge sections of the sheet metal parts with that arranged in FIG. 7 Cutting device 79 as close as possible to the formed Cut off areas of the sheet metal parts. The bowls 25, 26 get their finished shape, so with these No subsequent bending and / or bending of the shells Edge sections is necessary.

If the shells 25, 26, 27, 28 and between them arranged insulating material layers 35 and 36 formed , the two pairs of shells according to FIGS. 1 to 4 assembled and welded together. The welding takes place for example with the help of an electrode, whereby Welding material applied and the pairs lying against each other Edge cuts 25b, 26b, 27b, 28b of all four shells are welded together at the same time. The already mentioned welded joint 33 is formed.

The two multilayer and / or composite wall elements 23, 24 can therefore be used in the standard production with relative few forming operations from originally flat sheet metal parts and originally shaped and flat insulating material layers then connect them with a few welding processes become. Likewise, the entire exhaust device or whole exhaust guiding element 11 from relatively little originally separate Share educated and fast, easy and economical be assembled.

If the internal combustion engine 1 hot exhaust gas during operation generated, this flows through the inner lines 51 the supply lines 15 limited passages and the Entrance inner wall 45 limited in the flow direction expanding interior area and / or passage to the exhaust gas inlet area 42a of the catalyst body 42 of the catalyst means 41. The funnel-shaped collection and / or entrance inner wall 45 is used to collect the from various supply lines coming exhaust gas and for distribution from this to the exhaust gas entry surface 42a of the catalyst body 42. The collecting and / or entrance inner wall 45 conducts the exhaust gas in general and in particular central area i.e. in the vicinity of axis 22, parallel to this and approximately at right angles to the exhaust gas inlet area 42a against the latter. The exhaust gas then flows through through the passages of the catalyst body and thereby treated and cleaned catalytically. That with the exhaust gas outlet area 42b of the catalyst body 36 flowing out of this Exhaust gas then flows through in the direction of flow tapered interior of the funnel-shaped Exit inner wall 55 for derivation 57. The two lambda sensors 60 and 62 can increase the oxygen content of the exhaust gas or downstream of the catalyst means 41 measure up.

The compactly designed exhaust gas guide element 11 is claimed takes up little space and allows the catalyst 13 to be close to the Arrange internal combustion engine 1 and by relatively short leads to connect with this. The insulation material layers 35, 36 of the wall elements 23, 24, the intermediate layer 43 and the Containing air and / or more or less static exhaust gas Spaces 65, 67 result in good thermal insulation and isolate the gas-carrying parts of the exhaust manifold and the Catalyst thermally against the environment. The good thermal insulation also ensures that the exhaust gas between the Internal combustion engine and the catalyst agents cooled only a little becomes. This gives the advantage of a cold start, that originally the ambient temperature Catalyst means quickly on for effective Catalytic treatment and cleaning of the exhaust gas required Temperature to be heated.

The hot exhaust gas causes temporary different heating and expansion of the parts of the exhaust gas guide 11. The training and the way of installing the allow gas-carrying parts caused by temperature changes caused to record different dimensional changes, without generating excessive tension and damage.

The internal combustion engine 1 partially shown in FIG. 8 in turn has a motor housing 2 and exhaust gas outlets 3 with one another parallel axes 4. In Fig. 8 is also a part with an exhaust gas device or an exhaust gas guide element 111 an exhaust manifold 112 and a catalyst 113 can be seen. The housing 121 of the catalyst defines an axis 122. This in turn forms with the axes 4 parallel to one another an obtuse angle α. The exhaust manifold 112 and the catalyst 113 have two insulating multi-layer and / or composite wall elements 123, 124. These enclose in Cross section including a catalyst body 142 an exhaust gas entry surface 142a, an input inner wall 145 and inner lines 151.

The exhaust gas guide element 111 is generally of a similar design how the exhaust gas guide element 11 differs from this, however, in that the input section of the housing 121 and the collecting and / or input inner wall 145 in drawn axial section so bent and / or angled are that they are partially more or less along one straight, axis parallel to the axes 4. In the The exhaust gas flows using the exhaust gas guide element 111 accordingly in general and especially in the middle Cross-sectional area of the delimited by the inner wall 151 Interior area and / or passage more or less parallel to the axes 4 against the exhaust gas entry surface 142a. So the exhaust gas is slightly upstream of the interior area located from the exhaust gas entry surface 142a in general and to a large extent one Flow direction against the exhaust gas entry surface 142a is inclined and forms approximately the angle β with it different from 90 ° and namely 90 ° smaller than the angle α is.

Figures 9 and 10 show an exhaust device and an exhaust gas guide element 211 with an exhaust manifold 212 and a catalytic converter 213. The exhaust manifold has, for example four leads 215 and a connecting flange 217, which with Fasteners, such as screws, releasably can be attached to a motor housing. The catalyst 213 has a housing 221 that is generally rotationally symmetrical to an axis 222 and an input and an output Has.

The wall of the exhaust manifold 212 is nearby of the catalyst 213 a coherent in cross section Main section and away from this to the connection flange 217 protruding, in cross-section separated by gaps, finger-shaped sections. The main section and the are finger-shaped sections of the exhaust manifold wall by two multi-layer and / or composite wall elements 223 and 224 formed. Each of these forms approximately in cross section half of the wall and has a pair of metallic shells on. Each of these pairs has an outer shell 225 or 227 and an inner shell 226 and 228 respectively. The same pair belonging shells have middle sections between which an insulating material layer 235 or 236 is arranged. The Wall 224 of the catalyst also has two layers and / or composite wall elements 233, 234, each with a pair Shells and an insulating material layer. It should be noted that the four composite wall elements are omitted in Fig. 9 and were only drawn in FIG. 10.

The one formed from the two composite wall elements 233, 234 Wall of the catalyst housing encloses in cross section a metallic catalyst inner wall 240. This extends approximately over the entire axial dimension of the Composite wall elements 233, 234 and protrudes, for example, at the exit the catalyst even a little bit from the composite wall elements 233, 234 out. The housing 221 and the inner wall 240 have one along the exhaust flow path Collar parallel to axis 222, at least one in the longitudinal section shown in FIG. 10 widening Input section, a parallel to axis 222, cylindrical, approximately circular in cross section or main oval section, a tapered exit section and a substantially cylindrical collar or Approach. The main portion of the catalyst inner wall 240 contains catalyst agent 241 with a catalyst body 242. A deformable intermediate layer 243 is between the Inner wall 240 and the peripheral surface of the catalyst body arranged. For example, the inner wall consists of one one-piece sheet metal part or from two welded together Sheet metal parts.

A metallic one, for example made of one piece Sheet metal part existing collecting and / or entrance inner wall 245 is at least for the most part in the cross section from the composite wall elements 223, 224 of the exhaust manifold enclosed interior and is connected to the entrance of the Catalyst inner wall 240 connected, namely for example tightly welded. Each lead 215 has a different Connection flange 217 up to the collecting and / or entrance inner wall 245 extending and at least approximately dense as well as displaceable or rigidly connected to this inner line 251. The housing 221 has one at its exit between the inner shells of the composite wall elements 233, 234 and sleeve 253 protruding into the inner wall 240.

The four shells 225, 226, 227, 228 of the composite wall elements 223, 224 and the four shells of the composite wall elements 233, 234 have edge sections in cross section which are designed analogously and are welded together, like the four Shells 25 to 28 according to Figures 1 to 4. The four shells 225 to 228 are with the connection flange 217 with this, with each other and with the inner lines 251 of the supply lines 215 welded. The shells 225 to 228 are with you most downstream edge sections in pairs with each other and directly with the Entrance of the housing 221 located edge portions of the four Shells of the composite wall elements 233, 234 welded. The edge sections located at the exit of the housing 221 of the four shells of the composite wall elements 233, 234 welded together in pairs and with the sleeve 253. A metallic socket 259 is near the entrance of the Housing 221 of the catalyst in the wall of the Exhaust manifold 212 inserted and tight with a pair of shells this wall and the collecting and / or entrance inner wall 245 welded. The socket 259 has a Internal thread into which a lambda probe 260 is screwed.

The catalyst inner wall 240 is covered with it welded collecting and / or entrance inner wall 245, the Socket 259 and possibly other connections rigid with the Composite wall elements 223, 224 connected, which in turn rigid with the composite wall elements 233, 234 of the catalyst are connected. The catalyst inner wall 240 is also by at least one bead or the like in the housing 221 centered and limited axially displaceable. On free, air-containing space 265 separates the most of the inner lines 251, the entrance inner wall 245 and the catalytic converter inner wall 240 from those through the Composite wall elements 223, 224, 233, 234 formed walls.

Unless otherwise previously written, can the exhaust gas guide element 211 may be designed similarly to that Exhaust gas guide element 11. Furthermore, the composite wall elements 223, 224, 233, 234 similarly made and with each other are like the composite wall elements 23, 24.

When using the exhaust device or the exhaust guiding element 211 the hot exhaust gas flows from the openings of the connecting flange 217 through the inner lines 251 in the Interior of the inlet inner wall forming an exhaust manifold 245. The exhaust gas then flows into the interior, which from itself expanding entrance portion of the catalyst inner wall 240 is limited. The exhaust gas then flows through the passages of the catalyst body 242 and thereafter by that of Exit portion of the catalyst inner wall 240 limited Interior to the exit of the catalyst. The leading exhaust Parts are therefore practically along the entire flow path of the exhaust gas through the heat-insulating composite wall elements 223, 224, 233, 234 and through the air-containing space 265 thermally insulated from the environment. The Catalyst means 241 may also be replaced by the Liner 243 insulated. Research has shown that the outer shells 225 and 227 near the connection of the exhaust manifold with the catalytic converter only on one Temperature of about 230 ° C were heated. This Temperature is at least or about 300 ° C lower than at an exhaust gas guide element instead of the thermal insulation Composite wall elements 223, 224 only a single-layer, metallic Wall, but also an air space 265 has and otherwise approximately the same as the exhaust element 211 is trained. The free space 265 and the described arrangement of the exhaust gas-carrying parts also ensure that when operated by the Different strains caused by the heating various parts no excessive tension and damage cause.

In Fig. 11 is a part of an exhaust device or Exhaust gas guide element 311 shown in the essentially exclusively from an exhaust manifold 312 exists and has no catalyst. The exhaust manifold 312 has several, for example at least in places curved supply lines 315, one for all supply lines common connection flange 317, a collector or Collection section 318 and an output flange 319. Die Wall of the supply lines 315 and the collector or Collection section 318 consist of two multilayer and / or Composite wall elements 323, 324. Each of these has again a pair of metallic bowls and one Insulating material layer, as in the broken area of the Fig. 11 can be seen. Otherwise, the wall elements 323, 324, for example, similarly designed and with each other and be connected to the connection flange 317 as in FIG Fig. 10 shown wall elements 223, 224. The wall elements 323, 324 are at the collector or collection section 318 on their Ends facing away from the connecting flange 317 are also tight and rigidly connected to the output flange 319, namely welded.

The one enclosed by the two wall elements 323, 324 Interior contains a collection inner wall 345 and for each Lead an inner line 351. The inner lines 351 are at the input end similar to those before described embodiments with the connecting flange 317 welded. The other ends of the inner lines 351 are welded to the collecting inner wall 345 so that the Passages of the inner pipes in the from the collecting inner wall enclosed collection interior. The inner wall 345 and the inner lines 351 are analogous to those previously described embodiments for the most part free spaces from the inner shells of the wall elements 323, 324 separately. The inner wall 345 protrudes, for example through the opening of the output flange 319 a little the interior delimited by the wall elements 323, 324 out and is separated by a free space from which the Opening of the outlet flange delimiting inner surface of the the latter separately. For example, the exhaust manifold is still provided with a lambda probe 360, which in the of the Collector inner wall 345 enclosed collector interior protrudes.

The one from the output flange 319 and the one from this protruding end of the collecting inner wall 345 formed for all leads 315 common outlet of the exhaust manifold is, for example, about a derivative not shown or possibly directly connected to a catalyst.

The exhaust devices or exhaust gas guide elements and their Manufacturing can be changed in several ways. It can, for example, describe features of various Embodiments can be combined. Furthermore, at least some or all of the welded connections can possibly be made from edge sections of the shells of the various Exemplary embodiments replaced by other connections become. The edge sections can, for example, at least Part by flanging and / or brazing and / or gluing be connected to each other.

The inner lines 51 of the shown in Figures 1 to 4 Embodiment can possibly with the Shells of the collecting and / or input inner wall 45 rigid connected, for example welded. The latter should then preferably be axially displaceable with respect to the Composite wall elements 23, 24. If the exit end sections the inner lines 51, however, with respect to the Collection and / or input inner wall 45 are displaceable, such as it further ahead for the embodiment according to the Figures 1 to 4 is described, the two shells 46, 47 of the input inner wall 45 of the one in FIGS. 1 to 4 shown embodiment instead after projecting outside between the edge sections of the shells 26, 28 and have welded edge sections with them. Everyone who common connection flanges 17, 217, for all supply lines 317 could be separated by several, with one or more of the feed lines 15 or 215 or 315 connected flanges be replaced. Furthermore, the catalyst agents instead of just a single catalyst body, two or more Have catalyst body. Furthermore, the or everyone Catalyst body made of coiled or stacked, with sheet metal elements provided with coatings his.

The insulating material can be used in the manufacture of a wall element before inserting between two metallic Bowls still covered with a thin plastic cover, held together and be protected. This envelope can then decomposed by heating the two shells together and / or burned, so that the plastic Shell material is converted into gas and escapes. You can also use the edge sections to form a Sheet metal parts serving wall element after inserting the insulating material even before forming some together Spot welding or the same with each other connect to the sheet metal parts and the insulating material temporarily to fix.

Claims (16)

Exhaust gas guide element with at least two Supply lines (15, 215, 315) for connecting to a Internal combustion engine (1) and a wall, thereby characterized in that the wall has two wall elements (23, 24, 123, 124, 223, 224, 323, 324) with two each metallic shells (25, 26, 27, 28, 225, 226, 227, 228) and a layer (35, 36, 235, 236) made of heat-insulating material and that the two wall elements (23, 24, 123, 124, 223, 224, 323, 324) interconnected edge sections (25b, 26b, 27b, 28b) and together have cross-sections of interiors enclose all supply lines (15, 215, 315). Exhaust gas guide element according to claim 1, characterized characterized in that the layer (35, 36, 235, 236) thermal insulation material is microporous and at least too an essential part has a granular structure. Exhaust gas guide element according to claim 1 or 2, characterized in that the thermal insulation Material existing layer (35, 36, 235, 236) in essentially at least 2 mm and for example at least Is 3 mm thick. Exhaust gas guide element according to one of claims 1 to 3, characterized in that each shell (25, 26, 27, 28, 225, 227, 228) is in one piece that the for same wall element (23, 24, 123, 124, 223, 224, 323, 324) belonging shells (25, 26, 27, 28, 225, 226, 227, 228) essentially along their entire circumference connected and trained so firmly that they are self-supporting together, and that at least one substantial part of the wall exclusively from the Wall elements (23, 24, 123, 124, 223, 224, 323, 324) consists. Exhaust gas guide element according to one of claims 1 to 4, characterized in that all shells (25, 26, 27, 28, 225, 226, 227, 228, 325, 326) of the two at Edge sections (25b, 26b, 27b, 28b) with each other connected wall elements (23, 24, 123, 124, 223, 224, 323, 324) at the edge sections (25b, 26b, 27b, 28b) touch at least in pairs and by welding and / or brazing and / or gluing and / or flanging are connected to one another at least approximately tightly. Exhaust gas guiding elements according to one of claims 1 to 5, characterized in that the wall elements (23, 24, 123, 124, 223, 224, 323, 324) at least in the largest Part of the wall the extreme limit of the Form exhaust guiding element. Exhaust gas guide element according to one of claims 1 to 6, characterized in that each feed line (15, 215, 315) of the exhaust manifold (12, 112, 212, 312) one Exhaust gas passage limits that the exhaust gas passages of the Supply lines (15, 215, 315) with one for all supply lines (15, 215, 315) common collecting interior connected are and that the two together are interiors of the Wall elements enclosing supply lines (15, 215, 315) (23, 24, 123, 124, 223, 224, 323, 324) together in Cross section also at least a substantial part of the Enclose the collecting interior. Exhaust gas guide element according to one of claims 1 to 7, characterized in that each feed line (15, 215, 315) has an inner line (51, 151, 251) which in cross-section at least in part by a free one Gap (65, 265) of which they are in cross section enclosing wall elements (23, 24, 123, 124, 223, 224, 233, 234) is separated and an exhaust passage limited. Exhaust gas guide element according to claim 8 characterized in that there is a collecting inner wall (45, 145, 245, 345), at least for the most part through a free space (65) of which they are in Wall elements (23, 24, 123, 124, 223, 224, 323, 324) is separated and a collecting interior with which the inner lines (51, 151, 251) of all supply lines (15, 215, 315) are connected. Exhaust gas guide element according to claim 9, characterized in that the inner pipe (51, 151, 251) everyone Supply line (15, 215, 315) one rigid with the two Wall elements (23, 24, 123, 124, 223, 224, 323, 324) connected input end section and one with the Collective inner wall (45, 145, 245, 345) connected Has exit end section and that the exit section each inner pipe (51, 151, 251) with respect to the collecting inner wall (45, 145, 245, 345) and / or the latter with regard to the wall elements (23, 24, 123, 124, 223, 224, 323, 324) is displaceable. Exhaust gas guide element according to one of claims 1 to 10, characterized in that there is an additional Catalyst (13, 113, 213) with catalyst means (41, 241) for the catalytic treatment of the exhaust gas and that the two wall elements (23, 24, 123, 124, 223, 224) or two connected to them, additional wall elements (233, 234) with one pair each metallic shells and one between them existing layer of heat insulating material Enclose cross-section of catalyst medium (41, 42). Exhaust gas guide element according to claim 11, characterized characterized that the two additional wall elements (233, 234) directly and rigidly with the interiors of the Exhaust manifold leads (215) (212) enclosing wall elements (223, 224) are connected. Exhaust gas guide element according to one of claims 1 to 12, characterized in that the interiors together of the supply lines (15, 215, 315) enclosing Wall elements (23, 24, 123, 223, 224, 323, 324) one each assigned to the feed lines (15, 215, 315), finger-shaped, separated by spaces Have sections. Process for producing a Exhaust gas guiding element according to one of claims 1 to 13, characterized in that for each wall element (23, 24, 123, 124, 223, 224, 323) two sheet metal parts are provided, each of which is used to form one of the shells (25, 26, 27, 28, 225, 226, 227, 228, 325, 326) serves that one layer (35, 36, 235, 236) thermal insulation material between the two sheet metal parts is arranged and that the two sheet metal parts and the layer (35, 36, 235, 236) arranged between them then be reshaped together in such a way that the two wall elements (23, 24, 123, 124, 223, 224, 323) together in cross-section interiors of the supply lines (15, 215, 315). A method according to claim 14, characterized characterized that each layer (35, 36, 235, 236) insulating material when forming sheet metal parts and the layer (35, 36, 235, 236) is compressed such that the layer (35, 36, 235, 236) in the finished exhaust gas guide element in essentially at least 2 mm and for example at least Is 3 mm thick. A method according to claim 14 or 15, characterized characterized that two pairs of shells (25, 26, 27, 28, 225, 226, 227, 228) arranged in between Layers (35, 36, 235, 236) to form two im Cross-section together enclosing an interior Wall elements (23, 24, 123, 124, 223, 224, 324, 325) and that after molding the shells (25, 26, 27, 28, 225, 226, 227, 228) edge sections (25b, 26b, 27b, 28b) of all shells (25, 26, 27, 28, 225, 226, 227, 228) of the two wall elements (23, 24, 123, 124, 223, 224, 324, 325) simultaneously by welding and / or Brazing and / or gluing and / or flanging together get connected.

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