EP0757163A1 - Catalyst housing - Google Patents

Catalyst housing Download PDF

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Publication number
EP0757163A1
EP0757163A1 EP96112584A EP96112584A EP0757163A1 EP 0757163 A1 EP0757163 A1 EP 0757163A1 EP 96112584 A EP96112584 A EP 96112584A EP 96112584 A EP96112584 A EP 96112584A EP 0757163 A1 EP0757163 A1 EP 0757163A1
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EP
European Patent Office
Prior art keywords
funnels
exhaust
tube
exhaust gas
dividing line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP96112584A
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German (de)
French (fr)
Inventor
Hermann Ermer
Apostolos Kourtidis
Walter Dr. Stoepler
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Leistritz AG and Co Abgastechnik
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Leistritz AG and Co Abgastechnik
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Publication date
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Publication of EP0757163A1 publication Critical patent/EP0757163A1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/08Other arrangements or adaptations of exhaust conduits
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/011Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more purifying devices arranged in parallel
    • F01N13/017Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more purifying devices arranged in parallel the purifying devices are arranged in a single housing
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/24Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
    • F01N3/28Construction of catalytic reactors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/24Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
    • F01N3/28Construction of catalytic reactors
    • F01N3/2839Arrangements for mounting catalyst support in housing, e.g. with means for compensating thermal expansion or vibration
    • F01N3/2853Arrangements for mounting catalyst support in housing, e.g. with means for compensating thermal expansion or vibration using mats or gaskets between catalyst body and housing
    • F01N3/2857Arrangements for mounting catalyst support in housing, e.g. with means for compensating thermal expansion or vibration using mats or gaskets between catalyst body and housing the mats or gaskets being at least partially made of intumescent material, e.g. unexpanded vermiculite
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2470/00Structure or shape of gas passages, pipes or tubes
    • F01N2470/16Plurality of inlet tubes, e.g. discharging into different chambers

Definitions

  • the invention relates to a catalyst housing for multi-flow, in particular double-flow exhaust systems.
  • a separate exhaust line from the outlet of a cylinder to the end of the exhaust system, if possible, in order to oppose the lowest possible resistance to the exhaust gas flow.
  • the exhaust gases of several cylinders are brought together in a common exhaust line. In this common exhaust line, the exhaust gases flow through the entire exhaust system with their catalysts and silencers. The exhaust gases are brought together in a pant-like tube, the two tube ends corresponding to the pant legs of which are assigned to individual cylinders.
  • the flow cross-section of the exhaust gas line changes in the transition area from the two partial lines corresponding to the trouser legs to the common exhaust line.
  • a pressure wave generated by the exhaust gas flow from one sub-branch runs back into the adjacent sub-branch. This is not a problem if the adjacent partial strand itself is not acted upon by an exhaust gas stream at the moment the returning shaft enters. Otherwise, the returning wave would at least impede the outflow of the exhaust gas flow, in extreme cases even completely prevent the decompression of the adjacent cylinder.
  • catalysts in particular pre- or starting catalysts, as close as possible to the cylinder outlet. This attachment close to the engine ensures that the catalytic converter heats up quickly due to the exhaust gases flowing through it. The warmer the exhaust gases flowing through the catalyst, the faster the catalyst heats up. The catalyst only achieves its full effect when it is heated up.
  • the use of a single catalytic converter housing has the advantage that the resulting unit is smaller than would be the case if two separate catalytic converter housings were used.
  • the use of only one catalyst housing that is to say a single sheet metal jacket for a single monolith, has the advantage that the weight of the catalyst is significantly reduced. Because of the reduced effective mass, the temperature radiation from the catalyst housing is also effectively reduced. By reducing the temperature radiation, the thermal behavior of the catalyst is improved in that it is faster starts ", so it reaches its operating temperature faster, i.e. its full performance.
  • the use of only one housing has the advantage that little material is required, which lowers the material costs.
  • a single part is easier to transport in production. Only one part has to be transported, installed and packed.
  • the invention has for its object to design an exhaust gas catalytic converter so that it is as space-saving as possible and at the same time has a high thermal load capacity.
  • the solution to the problem consists in an extension of the dividing line between the two adjacent exhaust pipes and the inevitably associated enlargement of the separating area on the one hand and the distribution of the temperature gradient over as many exhaust gas channels of the honeycomb-like structured monolith on the other.
  • the dividing line between the two exhaust gas lines has an essentially odd course.
  • This odd course of the dividing line also has the advantage that less thermal stress occurs along the dividing line.
  • an odd dividing line has the advantage that, in contrast to a straight dividing line, there is no expansion of the housing in the region of the dividing line, which results in a voltage drop in the swelling mat holding the ceramic monoliths in the housing. A voltage drop in the source mat must be prevented simply because otherwise the catalytic converter will fail completely is preprogrammed ".
  • An S-shaped or a sinusoidal course of the dividing line between the two flows of the exhaust line is particularly advantageous.
  • the exhaust lines or the exhaust gas flows of the exhaust system in the areas outside the one-piece catalytic converter block are usually cylindrical.
  • the cylindrical tubes then open into D-shaped funnels according to the prior art or into funnels with a curved dividing line according to the invention, preferably into funnels with a sinusoidal dividing line.
  • the funnels are in turn connected to the catalyst housing.
  • the exhaust gas streams flow from the individual floods into the catalytic converter housing and the monoliths arranged therein, flow through the monolith in the individual channels that form the honeycomb structure of the monolith and flow out into conventional exhaust pipes via two further funnels adapted at the catalytic converter outlet.
  • exhaust pipes with a sinusoidal dividing line also has the advantage that two planes of symmetry are present, so that two identical funnels can be rotated next to each other by 180 °. Only a single funnel tool is then required to manufacture the funnels, which advantageously reduces the tool costs.
  • the funnels 2 connect to the exhaust pipes (not shown in the drawings) in the direction of flow 1.
  • the funnels 2 have cylindrical pipe sections 3 for the cylindrical exhaust pipes. In the flow direction 1 next to the pipe sections 3, the funnels 2 expand.
  • the funnels 2 have a semi-oval outer skin 4 in those areas in which they do not touch each other.
  • the funnels 2 also form the S-shaped or sinusoidal dividing line 5 with one another.
  • FIGS. 3 and 4 it is possible to arrange an essentially cylindrical main catalytic converter in the area of the engine compartment.
  • two manifold outlets each open into a single, cylindrical exhaust pipe with a partition in the direction of flow.
  • This exhaust pipe is connected to the cylindrical pipe section 3 in FIG. 3.
  • the pipe section 3 for the exhaust pipe which is divided in two by means of a partition, is still flanked by a fixing flange 7.
  • the funnel 2 also widens in the flow direction 1 in this embodiment.
  • the flow channel is initially divided into two parts by a straight partition 6 aligned with the partition in the exhaust pipe.
  • the partition 6 is also S-shaped in the further course.
  • the partition 6 is thus deformed into a sinusoidal dividing line 5. This is clearly visible in the area of the funnel outlet 8 shown in FIG. 4. In the direction of flow 1, the sheet metal jacket 9 of the actual catalyst housing adjoins the funnel outlet 8. The monolith, which cannot be seen in the drawings, is held in the sheet metal jacket 9 by the swelling mat 10.
  • partition plates in particular tend to flutter at high temperatures around 1000 ° C., which is disadvantageous in terms of noise and in particular affects the strength of the catalyst because can destroy the divider 6 itself by fluttering. This self-destructive effect due to the flutter is effectively avoided by the sinusoidal design of the S-shaped separating plate.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The catalyser includes a housing with two funnels (2) which form a sinusoidal dividing line (5) with each other. The exhaust tubes connect to the funnels (2) in the flow direction (1). The funnels have cylinder-shaped tube sections (3) for the cylinder-shaped exhaust tubes. In the flow direction near to the tube sections the funnels widen. The funnels have a semi-oval outer skin (4) in the areas where they do not contact each other. It is possible to fit a cylindrical catalyser in the area of the engine chamber. Two bend outlets issue in a single, cylindrical exhaust gas tube with a dividing wall in the flow direction. The exhaust gas tube is connected with the cylindrical tube section (3). This tube section, for the exhaust tube, is divided into two parts by a dividing wall and is flanked by a fixation flange.

Description

Die Erfindung betrifft ein Katalysatorgehäuse für mehrflutige, insbesondere zweiflutige Abgasanlagen. Bei Verbrennungsmotoren wäre es zur optimalen Ausbeute der Leistung bzw. des Drehmoments vorteilhaft, möglichst jeweils einen separaten Abgasstrang vom Auslaß eines Zylinders bis zum Ende der Abgasanlage zu führen, um dem Abgasstrom möglichst geringe Widerstände entgegenzusetzen. Da für den Einbau der Abgasanlage jedoch nur ein begrenzter Einbauraum in der Bodengruppe des Fahrzeugs zur Verfügung steht, werden die Abgase mehrerer Zylinder in einen gemeinsamen Abgasstrang zusammengeführt. In diesem gemeinsamen Abgasstrang durchströmen die Abgase die gesamte Abgasanlage mit ihren Katalysatoren und Schalldämpfern. Die Zusammenführung der Abgase erfolgt in einem hosenartigen Rohr, dessen beide den Hosenbeinen entsprechenden Rohrenden jeweils einzelnen Zylindern zugeordnet sind. Im Übergangsbereich von den beiden den Hosenbeinen entsprechenden Teilsträngen zum gemeinsamen Abgasstrang ändert sich der Strömungsquerschnitt der Abgasleitung. Infolge dieser Querschnittsänderung läuft jeweils eine vom Abgasstrom aus dem einen Teilstrang erzeugte Druckwelle in den benachbarten Teilstrang zurück. Dies ist unproblematisch, wenn der benachbarte Teilstrang im Moment des Eintritts der rücklaufenden Welle selbst nicht von einem Abgasstrom beaufschlagt ist. Andernfalls würde die rücklaufende Welle nämlich das Abströmen des Abgasstroms zumindest behindern, im Extremfall die Dekompression des benachbarten Zylinders sogar völlig verhindern.The invention relates to a catalyst housing for multi-flow, in particular double-flow exhaust systems. For internal combustion engines, it would be advantageous for the optimum yield of the power or the torque to run a separate exhaust line from the outlet of a cylinder to the end of the exhaust system, if possible, in order to oppose the lowest possible resistance to the exhaust gas flow. However, since only a limited installation space is available in the floor assembly of the vehicle for the installation of the exhaust system, the exhaust gases of several cylinders are brought together in a common exhaust line. In this common exhaust line, the exhaust gases flow through the entire exhaust system with their catalysts and silencers. The exhaust gases are brought together in a pant-like tube, the two tube ends corresponding to the pant legs of which are assigned to individual cylinders. The flow cross-section of the exhaust gas line changes in the transition area from the two partial lines corresponding to the trouser legs to the common exhaust line. As a result of this change in cross section, a pressure wave generated by the exhaust gas flow from one sub-branch runs back into the adjacent sub-branch. This is not a problem if the adjacent partial strand itself is not acted upon by an exhaust gas stream at the moment the returning shaft enters. Otherwise, the returning wave would at least impede the outflow of the exhaust gas flow, in extreme cases even completely prevent the decompression of the adjacent cylinder.

Auch das Auftreten der rücklaufenden Welle könnte wiederum durch die Verwendung sehr langer Rohrabschnitte im Bereich der den Hosenbeinen entsprechenden Rohrenden des Hosenrohrs gelindert werden, was aufgrund des nur begrenzt zur Verfügung stehenden Einbauraums jedoch praktisch nicht möglich ist. Zur Vermeidung dieses Problems werden deshalb üblicherweise die Auslässe zweier Zylinder mittels eines hosenartigen Rohrs in einem gemeinsamen Abgasstrang miteinander gebündelt, welche aufgrund der Zündfolge des Motors weder gleichzeitig noch kurzzeitig hintereinander dekomprimieren. Auf diese Weise ist wirksam verhindert, daß die rücklaufende Welle aus dem dem einen Hosenbein entsprechenden Rohrende auf den im benachbarten Rohrende geführten Abgasstrom auftrifft.The occurrence of the returning wave could in turn be caused by the use of very long pipe sections in the area corresponding to the trouser legs Tube ends of the downpipe are alleviated, but this is practically not possible due to the limited space available. To avoid this problem, the outlets of two cylinders are therefore usually bundled together in a common exhaust line by means of a trouser-like tube, which decompress due to the ignition sequence of the engine neither simultaneously nor briefly in succession. In this way it is effectively prevented that the returning shaft from the pipe end corresponding to the one trouser leg strikes the exhaust gas flow guided in the adjacent pipe end.

Bei Abgasanlagen mit Abgaskatalysatoren ist es zusätzlich wünschenswert, Katalysatoren, insbesondere Vor- oder Startkatalysatoren, möglichst nahe am Zylinderauslaß anzubringen. Diese motornahe Anbringung gewährleistet nämlich ein schnelles Aufheizen des Katalysators durch die ihn durchströmenden Abgase. Je wärmer nämlich die den Katalysator durchströmenden Abgase sind, desto schneller heizt der Katalysator auf. Erst im aufgeheizten Zustand erzielt der Katalysator seine vollständige Wirkung.In exhaust gas systems with exhaust gas catalysts, it is additionally desirable to mount catalysts, in particular pre- or starting catalysts, as close as possible to the cylinder outlet. This attachment close to the engine ensures that the catalytic converter heats up quickly due to the exhaust gases flowing through it. The warmer the exhaust gases flowing through the catalyst, the faster the catalyst heats up. The catalyst only achieves its full effect when it is heated up.

Bei der Serienfertigung von Kraftfahrzeugen kommt das Problem hinzu, daß dieselbe Karosserievariante mit mehreren Motoren unterschiedlicher Leistung bzw. unterschiedlichen Hubvolumens bestückt wird. Bei Motoren mit kleinerer Leistung, welche üblicherweise auch wenig Bauraum beanspruchen, kann der Hauptkatalysator problemlos motornah angeordnet werden. Bei größeren, den Motorraum vollständig ausfüllenden Motoren besteht jedoch das Problem, daß im Motorraum kein Platz mehr zur Anordnung des Katalysators vorhanden ist. Diese Raumproblematik wird zusätzlich dadurch verschärft, daß das erforderliche Katalysatorvolumen das 1 bis 1,2-fache des Motorhubraums beträgt. Das erforderliche Katalysatorvolumen steigt also proportional zum Hubraum an.In the series production of motor vehicles, there is the additional problem that the same body variant is equipped with several engines of different output or different stroke volumes. The main catalytic converter can easily be arranged close to the engine for engines with lower output, which usually also take up little space. With larger engines that completely fill the engine compartment, there is the problem that there is no more space in the engine compartment for arranging the catalytic converter. This problem of space is further exacerbated by the fact that the required catalyst volume is 1 to 1.2 times the engine displacement. The required catalyst volume therefore increases in proportion to the cubic capacity.

Es ist deshalb - beispielsweise aus der DE-A-27 25 943 - bekannt, mehrere Abgasstränge in ein Katalysatorgehäuse münden zu lassen. In diesem Katalysatorgehäuse ist üblicherweise ein Katalysatormonolith mit wabenartiger Struktur angeordnet. Die wabenartige Struktur ergibt sich aus einer Vielzahl in Strömungsrichtung nebeneinander verlaufender, sehr dünner Durchlaßkanäle durch den Monolithen. Die Durchlaßkanäle sind hierbei so ausgestaltet, daß eine Querströmung zwischen ihnen nicht stattfindet.It is therefore known - for example from DE-A-27 25 943 - to have several exhaust gas lines open into a catalytic converter housing. In this catalytic converter housing a catalyst monolith with a honeycomb structure is usually arranged. The honeycomb-like structure results from a large number of very thin passage channels running side by side in the flow direction through the monolith. The passage channels are designed so that there is no cross flow between them.

Die Verwendung eines einzigen Katalysatorgehäuses hat natürlich den Vorteil, daß die so entstehende Einheit kleiner ist als dies bei der Verwendung zweier separater Katalysatorgehäuse der Fall wäre. Des weiteren hat die Verwendung nur eines Katalysatorgehäuses, also eines einzigen Blechmantels für einen einzigen Monolithen den Vorteil, daß das Eigengewicht des Katalysators entscheidend verkleinert ist. Wegen der verkleinerten wirksamen Masse ist auch die Temperaturabstrahlung aus dem Katalysatorgehäuse wirksam verringert. Durch die Verringerung der Temperaturabstrahlung ist das thermische Verhalten des Katalysators dahingehend verbessert, daß er schneller

Figure imgb0001
anspringt", also schneller seine Betriebstemperatur, also seine volle Leistungsfähigkeit erlangt.Of course, the use of a single catalytic converter housing has the advantage that the resulting unit is smaller than would be the case if two separate catalytic converter housings were used. Furthermore, the use of only one catalyst housing, that is to say a single sheet metal jacket for a single monolith, has the advantage that the weight of the catalyst is significantly reduced. Because of the reduced effective mass, the temperature radiation from the catalyst housing is also effectively reduced. By reducing the temperature radiation, the thermal behavior of the catalyst is improved in that it is faster
Figure imgb0001
starts ", so it reaches its operating temperature faster, i.e. its full performance.

Zudem hat die Verwendung nur eines Gehäuses den Vorteil, daß wenig Material benötigt wird, was die Materialkosten senkt. Zudem ist ein einziges Teil in der Fertigung leichter transportierbar. Es muß nämlich nur ein einziges Teil transportiert, verbaut und verpackt werden.In addition, the use of only one housing has the advantage that little material is required, which lowers the material costs. In addition, a single part is easier to transport in production. Only one part has to be transported, installed and packed.

Da für ein Katalysatorgehäuse auch nur ein Monolith benötigt wird, senkt dies die Kosten zusätzlich. Die Notwendigkeit der Fertigung nur eines Monolithen bringt ebenfalls die vorerwähnten Vorteile fertigungstechnischer und logistischer Natur mit sich. Darüberhinaus ist es wegen des hohen Edelmetallanteils am Katalysator kostensparend, nur ein Bauteil edelmetallisch beschichten zu müssen.Since only one monolith is required for a catalytic converter housing, this further reduces the costs. The necessity of producing only one monolith also brings with it the advantages mentioned in terms of manufacturing technology and logistics. In addition, because of the high proportion of noble metal in the catalyst, it is cost-saving to have to coat only one component with a noble metal.

Es ist weiterhin bekannt, zur Einleitung zweier Abgasstränge in ein Katalysatorgehäuse D-förmige Abgasrohre nebeneinander anzuordnen, welche um 180° zueinander verschwenkt sind. Durch die Verschwenkung um 180° kommen nämlich die D-Flachseiten der D-förmigen Rohre aneinander zu liegen. Zwischen beiden Rohren entsteht also eine gerade, im Montageendzustand senkrecht verlaufende Trennlinie. Nachteilig hierbei ist, daß infolge des Aufheizens des Katalysators genau entlang dieser geraden Trennlinie Verformungen auftreten. Insbesondere wenn eine Temperaturdifferenz zwischen beiden Abgasfluten besteht oder im Extremfall nur eine Flut beheizt ist, tritt die Temperaturdifferenz zwischen beiden Fluten ebenfalls exakt entlang dieser geraden Trennlinie auf. Dieser gerade Verlauf der Temperaturtrennlinie führt in der Regel zu einem Bruch des wabenartig aufgebauten Katalysatormonolithen. Zudem wirkt sich verschärfend aus, daß die Waben des Monolithen üblicherweise achsparallel im Katalysatorgehäuse angeordnet sind, so daß sich eine gerade Trennlinie hierbei geradezu als Sollbruchlinie für die Keramik auswirkt.It is also known to arrange D-shaped exhaust pipes next to one another for introducing two exhaust gas lines into a catalytic converter housing, said exhaust pipes being pivoted through 180 ° to one another. By pivoting through 180 ° they come D flat sides of the D-shaped tubes to lie against each other. A straight dividing line is thus created between the two pipes when the assembly is finished. The disadvantage here is that deformations occur precisely along this straight dividing line due to the heating of the catalyst. In particular if there is a temperature difference between the two exhaust gas flows or, in extreme cases, only one flow is heated, the temperature difference between the two flows also occurs exactly along this straight dividing line. This straight course of the temperature separation line usually leads to a break in the honeycomb-like catalyst monolith. In addition, the fact that the honeycombs of the monolith are usually arranged axially parallel in the catalytic converter housing has an exacerbating effect, so that a straight dividing line here acts as a predetermined breaking line for the ceramic.

Ausgehend von diesen Problemen liegt der Erfindung die Aufgabe zugrunde, einen Abgaskatalysator so zu gestalten, daß er möglichst platzsparend ist und gleichzeitig eine hohe thermische Belastbarkeit aufweist.Based on these problems, the invention has for its object to design an exhaust gas catalytic converter so that it is as space-saving as possible and at the same time has a high thermal load capacity.

Die Lösung der Aufgabe besteht in einer Verlängerung der Trennlinie zwischen den beiden einander benachbarten Abgasrohren und der damit zwangsläufig verbundenen Vergrößerung der Trennfläche einerseits und der Verteilung des Temperaturgradienten über möglichst viele Abgaskanäle des wabenartig strukturierten Monolithen andererseits. Zur Lösung der Aufgabe ist es deshalb erforderlich, daß die Trennlinie zwischen beiden Abgassträngen einen im wesentlichen ungeraden Verlauf aufweist. Dieser ungerade Verlauf der Trennlinie hat zudem den Vorteil, daß entlang der Trennlinie ein geringerer Thermostreß auftritt. Zudem hat eine ungerade Trennlinie den Vorteil, daß im Gegensatz zu einer geraden Trennlinie keine Aufweitung des Gehäuses im Bereich der Trennlinie auftritt, welche einen Spannungsabfall der den Keramikmonolithen im Gehäuse halternden Quellmatte nach sich zieht. Ein Spannungsabfall der Quellmatte ist schon deshalb zu verhindern, weil andernfalls der Totalausfall des Katalysators geradezu

Figure imgb0001
vorprogrammiert" ist.The solution to the problem consists in an extension of the dividing line between the two adjacent exhaust pipes and the inevitably associated enlargement of the separating area on the one hand and the distribution of the temperature gradient over as many exhaust gas channels of the honeycomb-like structured monolith on the other. To achieve the object, it is therefore necessary that the dividing line between the two exhaust gas lines has an essentially odd course. This odd course of the dividing line also has the advantage that less thermal stress occurs along the dividing line. In addition, an odd dividing line has the advantage that, in contrast to a straight dividing line, there is no expansion of the housing in the region of the dividing line, which results in a voltage drop in the swelling mat holding the ceramic monoliths in the housing. A voltage drop in the source mat must be prevented simply because otherwise the catalytic converter will fail completely
Figure imgb0001
is preprogrammed ".

Besonders vorteilhaft ist ein S-förmiger bzw. ein sinusförmiger Verlauf der Trennlinie zwischen beiden Fluten des Abgasstrangs.An S-shaped or a sinusoidal course of the dividing line between the two flows of the exhaust line is particularly advantageous.

In diesem Zusammenhang sei angemerkt, daß die Abgasstränge bzw. die Abgasfluten der Abgasanlage in den Bereichen außerhalb des einstückigen Katalysatorblocks üblicherweise zylinderförmig sind. Die zylinderförmigen Rohre münden dann in D-förmige Trichter nach dem Stand der Technik oder in Trichter mit einer gebogenen Trennlinie nach der Erfindung, vorzugsweise in Trichter mit einer sinusförmigen Trennlinie. Die Trichter sind mit dem Katalysatorgehäuse wiederum verbunden. Die Abgasströme strömen aus den einzelnen Fluten in das Katalysatorgehäuse und den darin angeordneten Monolithen ein, durchströmen den Monolithen in den einzelnen, die Wabenstruktur des Monolithen bildenden Kanäle und strömen über zwei weitere, am Katalysatorausgang adaptierte Trichter wiederum in übliche Abgasrohre aus.In this context, it should be noted that the exhaust lines or the exhaust gas flows of the exhaust system in the areas outside the one-piece catalytic converter block are usually cylindrical. The cylindrical tubes then open into D-shaped funnels according to the prior art or into funnels with a curved dividing line according to the invention, preferably into funnels with a sinusoidal dividing line. The funnels are in turn connected to the catalyst housing. The exhaust gas streams flow from the individual floods into the catalytic converter housing and the monoliths arranged therein, flow through the monolith in the individual channels that form the honeycomb structure of the monolith and flow out into conventional exhaust pipes via two further funnels adapted at the catalytic converter outlet.

Die Verwendung von Abgasrohren mit sinusförmiger Trennlinie hat zudem den Vorteil, daß zwei Symmetrieebenen vorhanden sind, so daß jeweils zwei identische Trichter um 180° gegeneinander verdreht nebeneinander angeordnet werden können. Zur Fertigung der Trichter ist dann auch nur ein einziges Trichterwerkzeug erforderlich, was die Werkzeugkosten vorteilhaft senkt.The use of exhaust pipes with a sinusoidal dividing line also has the advantage that two planes of symmetry are present, so that two identical funnels can be rotated next to each other by 180 °. Only a single funnel tool is then required to manufacture the funnels, which advantageously reduces the tool costs.

Es sei jedoch ausdrücklich darauf hingewiesen, daß sich die Erfindung mit jedem anderen ungeraden Trennlinienverlauf, insbesondere mit jedem zick-zack-förmigen Trennlinienverlauf realisieren läßt.However, it should be expressly pointed out that the invention can be implemented with any other odd dividing line, in particular with any zigzag dividing line.

Anhand der beiden in den Figurenzeichnungen dargestellten Ausführungsbeispiele ist die Erfindung mit weiteren Merkmalen und Vorteilen erläutert. Es zeigen:

Fig. 1
eine Draufsicht auf ein zweiflutiges Katalysatorgehäuse,
Fig. 2
eine Seitenansicht des Katalysatorgehäuses gemäß Fig. 1, gesehen in Strömungsrichtung,
Fig. 3
eine Seitenansicht analog Fig. 2 einer weiteren Ausführungsform auf den Trichtereingang,
Fig. 4
die Ausführungsform gemäß Fig. 3 mit einer Seitenansicht auf den Trichterausgang.
On the basis of the two exemplary embodiments shown in the figure drawings, the invention is explained with further features and advantages. Show it:
Fig. 1
a plan view of a double-flow catalyst housing,
Fig. 2
2 shows a side view of the catalytic converter housing according to FIG. 1, seen in the flow direction,
Fig. 3
3 shows a side view analogous to FIG. 2 of a further embodiment of the funnel entrance,
Fig. 4
the embodiment of FIG. 3 with a side view of the funnel exit.

An die in den Zeichnungen nicht dargestellten Abgasrohre schließen sich in Strömungsrichtung 1 die Trichter 2 an. Die Trichter 2 weisen zylinderförmige Rohrabschnitte 3 für die zylinderförmigen Abgasrohre auf. In Strömungsrichtung 1 neben den Rohrabschnitten 3 weiten sich die Trichter 2 auf. Die Trichter 2 haben hierbei eine halbovale Außenhaut 4 in denjenigen Bereichen, in welchen sie einander nicht berühren. Die Trichter 2 bilden des weiteren die S-förmige bzw. sinusartige Trennlinie 5 miteinander aus.The funnels 2 connect to the exhaust pipes (not shown in the drawings) in the direction of flow 1. The funnels 2 have cylindrical pipe sections 3 for the cylindrical exhaust pipes. In the flow direction 1 next to the pipe sections 3, the funnels 2 expand. The funnels 2 have a semi-oval outer skin 4 in those areas in which they do not touch each other. The funnels 2 also form the S-shaped or sinusoidal dividing line 5 with one another.

In einer zweiten Ausführungsform gemäß Fig. 3 und Fig. 4 ist es möglich, einen im wesentlichen zylinderförmigen Hauptkatalysator im Bereich des Motorraums anzuordnen. Hierbei münden jeweils zwei Krümmerausgänge in ein einziges, zylinderförmiges Abgasrohr mit einer Trennwand in Strömungsrichtung. Dieses Abgasrohr ist mit dem zylinderförmigen Rohrabschnitt 3 in Fig. 3 verbunden. Der Rohrabschnitt 3 für das mittels einer Trennwand zweigeteilte Abgasrohr ist noch von einem Fixierflansch 7 flankiert. Im Anschluß an den Rohrabschnitt 3 weitet sich auch bei dieser Ausführungsform der Trichter 2 in Strömungsrichtung 1 auf. Im Bereich des Rohrabschnitts 3 ist der Strömungskanal zunächst von einer mit der Trennwand im Abgasrohr fluchtenden geraden Trennwand 6 zweigeteilt. Die Trennwand 6 ist im weiteren Verlauf ebenfalls S-förmig ausgebildet. Die Trennwand 6 wird also zu einer sinusartigen Trennlinie 5 verformt. Dies ist im Bereich des in Fig. 4 dargestellten Trichterausgangs 8 gut sichtbar. In Strömungsrichtung 1 schließt sich an den Trichterausgang 8 der Blechmantel 9 des eigentlichen Katalysatorgehäuses an. Im Blechmantel 9 ist von der Quellmatte 10 gehalten der in den Zeichnungen nicht erkennbare Monolith angeordnet.In a second embodiment according to FIGS. 3 and 4, it is possible to arrange an essentially cylindrical main catalytic converter in the area of the engine compartment. Here, two manifold outlets each open into a single, cylindrical exhaust pipe with a partition in the direction of flow. This exhaust pipe is connected to the cylindrical pipe section 3 in FIG. 3. The pipe section 3 for the exhaust pipe, which is divided in two by means of a partition, is still flanked by a fixing flange 7. Following the pipe section 3, the funnel 2 also widens in the flow direction 1 in this embodiment. In the area of the pipe section 3, the flow channel is initially divided into two parts by a straight partition 6 aligned with the partition in the exhaust pipe. The partition 6 is also S-shaped in the further course. The partition 6 is thus deformed into a sinusoidal dividing line 5. This is clearly visible in the area of the funnel outlet 8 shown in FIG. 4. In the direction of flow 1, the sheet metal jacket 9 of the actual catalyst housing adjoins the funnel outlet 8. The monolith, which cannot be seen in the drawings, is held in the sheet metal jacket 9 by the swelling mat 10.

Bei der in den Fig. 3 und 4 dargestellten Ausführungsform mit einem S-förmigen Trennblech 6 ist zusätzlich zu berücksichtigen, daß gerade Trennbleche bei hohen Temperaturen um 1000°C zu flattern neigen, was geräuschtechnisch nachteilig ist und insbesondere die Festigkeit des Katalysators beeinträchtigt, weil sich durch das Flattern das Trennblech 6 selbst zerstören kann. Dieser Selbstzerstörungseffekt infolge des Flatterns ist durch die sinusartige Ausgestaltung des S-förmigen Trennblechs wirksam vermieden.In the embodiment shown in FIGS. 3 and 4 with an S-shaped partition 6, it must also be taken into account that partition plates in particular tend to flutter at high temperatures around 1000 ° C., which is disadvantageous in terms of noise and in particular affects the strength of the catalyst because can destroy the divider 6 itself by fluttering. This self-destructive effect due to the flutter is effectively avoided by the sinusoidal design of the S-shaped separating plate.

BezugszeichenlisteReference list

11
StrömungsrichtungFlow direction
22nd
Trichterfunnel
33rd
RohrabschnittPipe section
44th
AußenhautOuter skin
55
Trennlinieparting line
66
Trennwandpartition wall
77
FixierflanschFixing flange
88th
TrichterausgangFunnel exit
99
BlechmantelSheet metal jacket
1010th
QuellmatteSwelling mat

Claims (2)

Katalysator mit einem aus einem Blechmantel (9) bestehenden Gehäuse und einem im Gehäuse angeordneten Monolithen, wobei zwei Abgasstränge mittels zweier Anschlußtrichter (2) mit dem Monolithen leitungsmäßig verbunden sind,
   dadurch gekennzeichnet,
daß beide Trichter (2) eine ungerade Trennlinie (5) miteinander ausbilden.
Catalytic converter with a housing consisting of a sheet metal jacket (9) and a monolith arranged in the housing, two exhaust lines being connected in line with the monolith by means of two connection funnels (2),
characterized,
that both funnels (2) form an odd dividing line (5) with each other.
Katalysator nach Anspruch 1,
   dadurch gekennzeichnet,
daß die von den beiden Trichtern (2) ausgebildete Trennlinie (5) einen sinusförmigen Verlauf aufweist.
Catalyst according to claim 1,
characterized,
that the dividing line (5) formed by the two funnels (2) has a sinusoidal shape.
EP96112584A 1995-08-04 1996-08-03 Catalyst housing Withdrawn EP0757163A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE29513179 1995-08-04
DE29513179U 1995-08-04

Publications (1)

Publication Number Publication Date
EP0757163A1 true EP0757163A1 (en) 1997-02-05

Family

ID=8011852

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96112584A Withdrawn EP0757163A1 (en) 1995-08-04 1996-08-03 Catalyst housing

Country Status (1)

Country Link
EP (1) EP0757163A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1482141A1 (en) * 2003-05-28 2004-12-01 J. Eberspächer GmbH & Co. KG Exhaust system for a vehicle internal combustion engine
DE102012017178A1 (en) * 2012-03-10 2013-09-12 Volkswagen Aktiengesellschaft exhaust gas purification device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE7045505U (en) * 1971-04-08 Boysen F Pipe connection, especially for an exhaust system
DE2725943A1 (en) * 1977-06-08 1978-12-21 Daimler Benz Ag Combustion engine exhaust catalyst - has inlet and outlet connections for separate exhaust entry and exit ducts
DE2745841A1 (en) * 1977-10-12 1979-04-19 Eberspaecher J Cylindrical catalytic silencer - with springy axial and radial location
US5148597A (en) * 1990-08-27 1992-09-22 Tennessee Gas Pipeline Company Method of making a collector device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE7045505U (en) * 1971-04-08 Boysen F Pipe connection, especially for an exhaust system
DE2725943A1 (en) * 1977-06-08 1978-12-21 Daimler Benz Ag Combustion engine exhaust catalyst - has inlet and outlet connections for separate exhaust entry and exit ducts
DE2745841A1 (en) * 1977-10-12 1979-04-19 Eberspaecher J Cylindrical catalytic silencer - with springy axial and radial location
US5148597A (en) * 1990-08-27 1992-09-22 Tennessee Gas Pipeline Company Method of making a collector device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1482141A1 (en) * 2003-05-28 2004-12-01 J. Eberspächer GmbH & Co. KG Exhaust system for a vehicle internal combustion engine
DE102012017178A1 (en) * 2012-03-10 2013-09-12 Volkswagen Aktiengesellschaft exhaust gas purification device

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