Stock material or miscellaneous articles – All metal or with adjacent metals – Honeycomb – or with grain orientation or elongated elements...
Reexamination Certificate
2000-12-05
2002-04-09
Zimmerman, John J. (Department: 1775)
Stock material or miscellaneous articles
All metal or with adjacent metals
Honeycomb, or with grain orientation or elongated elements...
C428S603000, C228S181000, C029S890000, C422S180000, C502S439000, C502S527220
Reexamination Certificate
active
06368726
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a honeycomb body configuration including a honeycomb body having a fluid inlet side and a fluid outlet side, in particular a catalyst support structure for motor vehicles, formed of at least partially structured layers of sheet metal which, after being stacked and/or wound, form channels through which a fluid can flow. The honeycomb body is surrounded by an inner tubular jacket and an outer tubular jacket provided concentrically thereto. At least an axial subregion of the inner tubular jacket is configured as a corrugated tube.
Honeycomb body configurations of this type are known per se. Published, Non-Prosecuted German Patent Application No. DE 2 300 704 describes, for example, ceramic honeycomb bodies having a metallic layer on their surface. Connected to this layer are elastic elements which, for their part, are mounted in turn in the outer tubular jacket. The elastic holding elements are, in particular, sections of corrugated tube which are intended to absorb the thermally induced relative movements between the honeycomb body and the outer tubular jacket. The elastic elements are provided either in two parts, in each case on the fluid inlet side and fluid outlet side, or in one part, over the overall length of the honeycomb body, and each have a flange for connection to a pipeline.
Also for metallic honeycomb bodies which are constructed of layers of sheet metal it is known, for example from Published, Non-Prosecuted German Patent Application DE 39 41 642 A1, for the purpose of preventing stresses due to thermal expansion, to surround layers of sheet metal with an outer metal tubular jacket having short corrugations at a short distance apart, with the result that a honeycomb body having an outer tubular jacket of this type is able to expand and shrink.
In the case of honeycomb body configurations having an inner and an outer tubular jacket which, at least in subregions, are intended to be displaceable relative to each other, there are also a large number of problems involving the manufacture because particularly when brazing or welding connections it has to be ensured in each case that undesirable additional connections between the two tubular jackets do not obstruct the mutual displaceability.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a honeycomb body configuration which overcomes the above-mentioned disadvantages of the heretofore-known configurations of this general type and which can be produced in a reproducible manner with uniform quality and ensures, by providing a good equalization of mechanical and thermal loads, a permanent and secure mounting of a honeycomb body constructed from layers of sheet metal in a metallic housing, even under special operating loads. It is a further object of the invention to achieve a good cold-starting performance of a catalytic exhaust gas cleaning device having the honeycomb body configuration according to the invention.
With the foregoing and other objects in view there is provided, in accordance with the invention, a honeycomb body configuration, including:
a honeycomb body formed of at least partially structured sheet metal layers, the at least partially structured sheet metal layers being stacked sheet metal layers and/or wound sheet metal layers and defining channels for a fluid to flow
therethrough, the honeycomb body having a fluid inlet side and a fluid outlet side;
an inner tubular jacket surrounding the honeycomb body;
an outer tubular jacket provided concentrically with respect to the inner tubular jacket and surrounding the honeycomb body;
the inner tubular jacket having a first longitudinal subregion and at least a second longitudinal subregion, the first longitudinal subregion having a first length including a first partial length, the second longitudinal subregion having a second length including a second partial length;
the inner tubular jacket being configured, in the first longitudinal subregion, as a corrugated tube having tubular corrugations such that the first longitudinal subregion is a corrugated subregion;
the second longitudinal subregion being a smooth subregion bearing flat against the honeycomb body;
the smooth subregion and the honeycomb body being joined at least at the second partial length; and
several of the tubular corrugations provided next to one another and the outer tubular jacket being joined at the first partial length, the first partial length being dimensioned for a conventional joining connection.
In other words, the honeycomb body configuration according to the invention includes a honeycomb body having a fluid inlet side and a fluid outlet side, in particular a catalyst support structure for motor vehicles, formed of at least partially structured layers of sheet metal which, after being laminated and/or wound, form channels through which a fluid can flow, the honeycomb body being surrounded by an inner tubular jacket and an outer tubular jacket provided concentrically thereto, and at least an axial subregion of the inner tubular jacket being configured as a flexible corrugated tube, having tubular corrugations, the inner tubular jacket having at least one further axial subregion which bears smoothly against the honeycomb body, and the smooth subregion and the honeycomb body being at least partially connected axially to each other by a join, a plurality of tubular corrugations provided next to one another of the corrugated subregion and the outer tubular jacket are partially connected axially to one another by a join, each corrugated subregion provided for connection to the outer tubular jacket by a join being dimensioned in its partial length such that conventional connecting methods, in particular soldering and/or welding processes, can be used.
Mechanical and thermal loads can be equally well equalized and a permanent and secure mounting configuration of the honeycomb body in the housing ensured in an advantageous manner by the inner tubular jacket of the honeycomb body having, in addition to an axial or longitudinal subregion configured as a flexible corrugated tube, having tubular corrugations, at least one further axial or longitudinal subregion which bears smoothly (flat) against the honeycomb body, and by a plurality of tubular corrugations provided next to one another of the corrugated subregion and the outer tubular jacket being partially connected to each other axially by a join, and by the smooth subregion and the honeycomb body being at least partially connected to each other axially by a join. According to the invention, each corrugated subregion provided for connection to the outer tubular jacket by a join is dimensioned in its partial length in such a manner that conventional connecting methods, in particular brazing and/or welding processes, can easily be used.
According to the invention, the honeycomb body configuration is preferably distinguished in that first of all a smooth subregion is provided on the fluid inlet side, followed by at least one corrugated subregion and at least one further smooth subregion, thereby resulting in a total of n corrugated subregions and n+1 smooth subregions, n being an integer and being greater than or equal to 1. By providing, on the fluid inlet side, a smooth subregion acting as an air-gap insulation, rapid starting of the catalytic reaction when beginning to be subjected to exhaust gas to be cleaned is ensured in an advantageous manner. As an alternative to the air-gap insulation, the thermal insulation can also be improved through the use of an insulating mat, for example made of ceramic material, which has very low heat-conducting and heat-convection properties.
In one particular embodiment, where n=1, the one corrugated subregion is predominantly provided on the fluid inlet side. As a result, the smooth section of the inner tubular jacket on the inlet side is only short, for example 5 to 25 mm, and in particular the mechanical loads on the fluid inlet side which are caused by exhaust gas strongly pulsating
Holpp Helmut
Siepmann Uwe
Emitec Gesellschaft für Emissionionstechnologie MBH
Greenberg Laurence A.
Lerner Herbert L.
Stemer Werner H.
Zimmerman John J.
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