Metal working – Method of mechanical manufacture – Catalytic device making
Reexamination Certificate
1998-09-17
2001-09-25
Hughes, S. Thomas (Department: 3726)
Metal working
Method of mechanical manufacture
Catalytic device making
C422S177000, C053S429000
Reexamination Certificate
active
06293009
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a method for producing a metallic carrier body. The invention also relates to a metallic carrier body, in particular a catalyst carrier body for exhaust gas systems of internal combustion engines.
Metallic carrier bodies, which are also referred to as honeycomb bodies, in particular catalyst carrier bodies for exhaust gas systems of internal combustion engines, are known, for example, from International Publication Nos. WO 92/02717 and WO 92/02716.
A feature common to all of those bodies is that they are formed of a plurality of individual sheets or layers which are at least partially structured. The sheets delimit flow channels, through which an exhaust gas can flow. The sheets are wound or coiled one around the other in order to form individual gas channels.
The activity of a catalyst carrier body, which is disposed within an exhaust gas system of an internal combustion engine, depends, inter alia, on the flow conditions in a metallic carrier body. In order to improve the flow conditions, it is proposed, according to International Publication No. WO 92/02717, that at least part of the sheets have structures running approximately parallel to the direction of flow. In at least part of those structured sheets the structures have structure heights and/or structure widths narrowing continuously or in steps in order to form channels having different cross-sectional areas. Another proposal for improving effectiveness and/or the flow conditions in a metallic carrier body is described in International Publication No. WO 92/02716, mentioned above. According to that publication, it is proposed that, as seen in the direction of flow of the channels, the carrier body be constructed in such a way that the number of channels per cross-sectional area, and consequently the cross-sectional area of individual channels, vary in different portions located one behind the other in the direction of flow.
Such carrier bodies have high effectiveness and a favorable flow behavior, which is advantageous particularly in the case of large exhaust gas volumes.
Such metallic honeycomb bodies are produced by laminating at least partially structured sheets so as to form at least one stack. The laminated stack or laminated stacks are subsequently coiled at least partially one around the other. The stacks that are coiled one around the other are thereafter introduced into a casing tube. The carrier body which is thus produced subsequently has brazing material applied to it and is subjected to a brazing operation, with the result that the individual sheets are connected to one another. In addition, a connection may be made between the sheets or layers and the casing tube. The outlay for producing such carrier bodies is relatively high.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a method for producing a metallic carrier body, and a metallic carrier body for an exhaust gas system of an internal combustion engine, which overcome the hereinafore-mentioned disadvantages of the heretofore-known methods and devices of this general type and in which the method simplifies the production of the carrier body and the carrier body has a simplified structure and high effectiveness.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for producing a metallic carrier body, in particular a catalyst carrier body for an exhaust gas system of an internal combustion engine, which comprises introducing at least one sheet into a receptacle while undergoing at least partial deformation of the at least one sheet.
The concept according to the invention of a method for producing a metallic carrier body, in particular a catalyst carrier body for an exhaust gas system of an internal combustion engine, follows an entirely novel route in order to produce metallic carrier bodies. Contrary to the known production method, in which an ordered structure of the carrier body is always formed, it is proposed, in the method according to the invention, to introduce at least one sheet into a receptacle, with that sheet at the same time undergoing at least partial deformation. The structure of the gas passages within the carrier body is produced through the use of the deformed sheet. An essentially completely unordered structure of gas passages, which communicate with one another, arises within the receptacle. This ensures that, when an exhaust gas flows through such a carrier body, it undergoes very good intermixing which leads to high effectiveness of a metallic carrier body used as a catalyst carrier body.
The method according to the invention also has the advantage of ensuring that there is no longer any need for lamination or stack formation before the actual production of the metallic carrier body.
It is possible to influence the essentially unordered structure of the carrier body by a suitable choice or variation of production parameters.
In accordance with another mode of the invention, the at least one sheet is introduced into the receptacle at a substantially constant speed during the production operation. This simplifies the production operation substantially, since there is no need for any complicated devices in order to produce the metallic carrier body. Another advantage of this procedure is that the deformation behavior of the sheet, which is introduced into the receptacle at a substantially constant speed, is always similar.
In order to increase the effectiveness of the production method, it is proposed to introduce a plurality of sheets into the receptacle simultaneously. These sheets influence one another in that they are at least partially deformed while they are being introduced into the receptacle.
In accordance with a further mode of the invention, when a plurality of sheets are introduced into the receptacle simultaneously, each sheet is introduced into the receptacle at a substantially constant speed. A method in which the speed of each sheet is substantially identical is preferred. It is thereby possible to convey all of the sheets into the receptacle through the use of a single drive.
The loading of the carrier body with at least one sheet and therefore also the size of a catalytically active surface also depend on the degree of deformation of the sheet.
In accordance with an added mode of the invention, the speed of each sheet is different in order to obtain portions which have different deformations within the carrier body and therefore to produce different portions of catalytically active surface. Preferably, the speed of at least one sheet is varied during the production operation. A method in which each sheet is introduced into the receptacle at varying speed is preferred. Varying the speed of each sheet in this way affords the possibility of producing a metallic carrier body which is adapted to a predetermined use or intended use.
In accordance with an additional mode of the invention, each sheet is introduced at substantially identically varying speeds. Alternatively, each sheet may be introduced into the receptacle at differently varying speeds.
In accordance with yet another mode of the invention, at least the direction in which at least one sheet is introduced into the receptacle is substantially constant, which also simplifies the production of a metallic carrier body. When a plurality of sheets are introduced into the receptacle, it is preferable that the direction in which each sheet is introduced into the receptacle is substantially constant.
In accordance with yet a further mode of the invention, in order to prevent zones in which there are large gas channels from occurring within the receptacle, the direction in which at least one sheet is introduced into the receptacle is varied. This may also take place correspondingly when a plurality of sheets are introduced into the receptacle. In this case, an identical variation in the direction of each sheet takes place. This measure also has the advantage of permitting the production of carrier
Emitec Gesellschaft fuer Emissions-technologie
Greenberg Laurence A.
Hong John C.
Hughes S. Thomas
Lerner Herbert L.
LandOfFree
Method for producing a metallic carrier body and metallic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing a metallic carrier body and metallic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing a metallic carrier body and metallic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2513854