DE102004055869A1 - Storage device for a ceramic catalyst of an internal combustion engine in a housing - Google Patents

Abstract

The ceramic catalyst is held in the housing via high temperature resistant elastic adhesive elements. Furthermore, a combination between a high temperature resistant adhesive ring and a wire knit ring is possible. Furthermore, it is also proposed to provide the mounting of two metallic spring elements, which are soldered to the housing and the ceramic catalyst.

Description

The The invention relates to a storage device for a Ceramic catalyst of an internal combustion engine according to the preamble of claim 1.

From the DE 22 43 251 a storage device for a monolith for exhaust gas purification is known, which is held at front side edges by means of rings of a wire mesh in a surrounding housing with an air gap. Furthermore, it is known to store ceramic catalysts in fiber mats and / or in fiber-containing swelling mats.

task The invention is an improved storage device for a Ceramic catalyst of an internal combustion engine to create in easy way without damage the catalyst is to be mounted, beyond a durable elastic Warehousing ensured wherein the storage device does not comprise releasable fibrous substances, is environmentally friendly and can be sorted separately.

These The object is solved by the features of claim 1. Further advantageous features include the subclaims.

The with the invention mainly The advantages achieved are that the bearings are made of high temperature resistant adhesives a temperature resistant, mechanically durable and gas-tight as well as permanently elastic connection between a ceramic catalyst and a surrounding housing. This is essentially achieved by the upstream and downstream of an exhaust gas stream of the internal combustion engine arranged two Bearings of the ceramic catalyst in the housing or in the housing jacket made of high temperature resistant elastic adhesive elements or of an elastic adhesive element and a wire knit ring over which the ceramic catalyst the air gap and tolerances bridged is storable. Furthermore, those made of high-temperature resistant existing two bearings of the ceramic catalyst in the housing in each case at least consisting of a ring element, which is arranged around the catalyst and on the case supportively are adjacent, wherein the one downstream or upstream arranged ring element the storage against exhaust gases is made gas-tight. This will be in Advantageous according to the invention, a storage of the sensitive ceramic carrier without soluble achieved fibrous substances and it is also a flow around the catalyst prevented by unpurified exhaust gas.

The mechanically durable adhesive element reaches even with special Demands, as in an off-road operation of the vehicle before everything in the subsoil area by rockfall and Aufsetzer or for vibrations caused by off-road excitation on rough roads takes place and general micro-movements, in particular by charge exchange the internal combustion engine the required life. Also compensate These permanently elastic adhesive elements have different thermal expansions of the ceramic carrier and the housing stainless steel within the width of the adhesive elements. Furthermore the adhesive element is temperature resistant and acts permanently as a fixed bearing of the catalyst storage. Even with special demands, like in a terrain operation especially in the underbody area when wading through penetrating water as well as by temperature shock from outside.

Further is provided according to the invention that the upstream or downstream arranged consisting of a high temperature resistant adhesive element Storage from storage carried out at least as three-point storage exists and the individual bearing elements each at an angle of about 120 ° to each other are arranged between the catalyst and the housing. By this arrangement is advantageously achieved according to the invention, that an easy-to-use catalyst achieved in the housing because there are only three points of contact to the housing consist.

In order to the catalyst or the housing itself under heat load can expand accordingly, a floating bearing can be provided which at least upstream of the exhaust stream but also downstream of the Exhaust stream can be arranged and which by the other gas-tight bearings added becomes.

by virtue of the elastic storage by the elastic adhesive rings or through the elastic adhesive elements of the ceramic catalyst after an execution the invention in cross-section oval-shaped or irregular shaped accomplished be. The adhesive elements can because of the elasticity create this oval shape in a simple manner. This is a easy adaptation of the storage to the outline of the catalyst possible.

The adhesive element has a composition that absorbs a maximum temperature of 1700 ° C and consists of felted glass fibers and Keramikikanteilen. Also, the bearings may consist of a high temperature resistant adhesive element and / or a wire knit ring, wherein this is then soldered to the ceramic catalyst and / or the housing. This also low assembly forces during production are required.

In Advantageously, according to the invention, the floating bearing for centering either by two high temperature resistant elastic adhesive elements or by a Drahtgestrickring- or pillow with sliding seat consist.

By the storage of the ceramic catalyst in the housing via high temperature resistant elastic Adhesive elements deleted a prior measurement of each ceramic carrier or housing, because the adhesive bridges tolerances. A carrier-related Calibration of the housing shell is eliminated the same reason. Functional impairments by e.g. missing Preload forces are eliminated also, as damage when stuffing the ceramic carrier is excluded with folded fiber mat in the housing jacket. Even during assembly, operation and recycling no need further environmental protection or occupational health and safety precautions because the materials used are environmentally friendly.

One Annular gap between the catalyst and the housing, as well as between fixed and Floating bearing acts as air gap insulation. The housing protects against mechanical damage Outside. The heat transfer outward is for a rapid onset of the catalyst and for a lower vehicle or engine compartment heating minimized. A thermal shock from the outside will not initiated directly on the sensitive catalyst.

To another embodiment of the invention instead of ring-shaped Adhesive elements as bearing elements also so-called. Moldings are used. These form bearings for the ceramic catalyst and are both on the housing and on the ceramic catalyst soldered. They are elastic and annular arranged circumferentially around the catalyst. These moldings are U-shaped or Z-shaped profile or in other profile shapes, such as V-, C-, S-shaped and form a gas-tight connection for the Exhaust gas flow. As a result, in an advantageous manner according to the invention achieved that an elastic buffer element in terms of tolerances is formed. Also, by the profile shape of the molded parts Voltage compensation takes place with heat, so that no more sliding seat is required. The centering of the catalyst in the housing becomes guaranteed. Furthermore, by the soldering the molded parts between the housing and achieved a gas-tight seal the catalyst.

embodiments The invention are illustrated in the drawings and are in Following closer described.

It demonstrate

1 a first embodiment of bearings for a catalyst with adhesive elements or with adhesive elements and Drahtgestrickringen and

2 a further embodiment of bearings for a ceramic catalyst via elastically formed annular shaped parts made of metal.

A ceramic catalyst 1 is in a housing 2 or within a housing shell in bearings 3 . 4 ; 12 . 13 held upstream and downstream of an exhaust stream 5 . 5a an exhaust system on front side edges 6 and 7 of the catalyst 1 this overarching in the housing 2 are arranged.

The bearings 3 . 4 consist of high-temperature-resistant permanently elastic adhesive elements, which are made of a catalyst all around 1 existing closed ring exist. At least one of these bearings 3 . 4 can also consist of so-called partial bearing elements A, B, C, which are arranged at circular cross sections in each case at an angle of about 120 ° to each other and form a so-called three-point bearing. This is in 1 rotated 90 ° to the catalyst 1 Shown on a dash-dotted circle K, the outline of the catalyst 1 represents. In other cross-sectional shapes then a corresponding number of bearings is provided.

One of the bearings 3 or 4 is in each case as so-called floating bearing and the other bearing is then designed as a so-called fixed bearing. In any case, the fixed bearing is made of a gas-tight adhesive element, so that no unpurified exhaust gas is the catalyst 1 between the ceramic carrier and the housing 2 can handle. The floating bearing is the bearing element in the case shown 3 , This may also consist of two elastic adhesive elements, wherein the one adhesive element in a closed ring shape then substantially for centering the catalyst 1 in the case 2 serves.

The storage of the ceramic catalyst 1 in the case 2 may also consist in combination of an annular adhesive member and a wire mesh ring, which then forms the floating bearing. The wire mesh ring is not shown. The housings can be designed longitudinally as profile tubes or in half shell construction.

The Adhesive elements have such a composition of felted Glass fibers and ceramic parts on that a temperature up to maximum 1700 ° C can be included.

As in the sectional drawing 1 shown in more detail, is the upstream storage 3 on the one hand in a corner E of a transition of the housing 2 to a funnel-shaped connecting pipe 8th . 8a to the exhaust pipe R and on the other hand, a corner edge 9 of the ceramic catalyst 1 arranged around. The camp 4 is also on the one hand in a corner E1 of a funnel-shaped connecting pipe 10 to the exhaust pipe R1 and on the other hand, a corner edge 11 of the ceramic catalyst 1 arranged around. These bearings arranged in this way 3 . 4 cause in addition to a stable and solid and a vibration-insulated storage of the catalyst 1 ,

According to one embodiment, the ceramic catalyst 1 instead of a circular cross-section also have an oval-shaped cross-section or irregularly shaped cross-sections and the elastic bearing elements 3 . 4 settle easily in the corner area E, E1 and support the catalyst 1 in the case 2 from.

When using a Drahtgestrickring used in combination with the adhesive element as a storage this can be a ceramic-metal soldering with the catalyst 1 and / or the housing 2 get connected.

According to another embodiment of the invention gem. 2 can the bearings 12 . 13 for the ceramic catalyst 1 in the case 2 also made of elastic molded parts 14 . 15 consist, the ring-shaped running and all around the catalyst 1 are arranged. These moldings 14 . 15 are U, V, C, S or Z-shaped profiled and made of metal and are with the housing 2 and the catalyst 1 soldered. The local arrangement can be both on the corner as well as in a peripheral region of the catalyst, such as 2 shows.

Depending on the requirements, there are therefore various combinations of the bearings for the catalyst 1 in the case 2 possible, so instead of an elastic metallic molding 14 or 15 also an adhesive element 3 or 4 in combination with a molded part 14 or 15 be used.

Claims (10)

Storage device for a ceramic catalyst of an internal combustion engine in a surrounding housing having elastic bearings, which are supported in the housing and keep the catalyst with an air gap between the bearings, characterized in that the upstream and downstream of an exhaust gas flow ( 5 . 5a ) arranged at least two bearings ( 3 . 4 ; 12 . 13 ) of the ceramic catalyst ( 1 ) in the housing ( 2 ) made of high temperature resistant elastic adhesive elements ( 3 or 4 ) or molded parts ( 12 . 13 ), over which the ceramic catalyst ( 1 ) with the air gap (L) in the housing ( 2 ) is stored. Storage device according to claim 1, characterized in that the bearings ( 3 . 4 ) of the ceramic catalyst ( 1 ) in the housing ( 2 ) each consist of at least one ring element which surrounds the catalyst ( 1 ) and on the housing ( 2 ) are abutting supporting and that at least one of the downstream or upstream ring elements of the storage ( 3 . 4 ) is designed gas-tight against exhaust gases. Storage device according to claims 1 or 2, characterized in that a consisting of the high temperature resistant adhesive elements storage ( 3a ) consists of at least one three-point bearing with bearing elements (A, B and C) and these bearing elements (A, B and C) at a circular cross section in each case at an angle of about 120 ° to each other between the catalyst ( 1 ) and the housing ( 2 ) are arranged. Storage device according to claims 1, 2 or 3, characterized in that the upstream storage ( 3 ) as a loose or fixed bearing and the further downstream storage ( 4 ) is designed as a fixed or floating bearing. Storage device according to one of the preceding claims, characterized in that the catalyst ( 1 ) consists of any cross-section and about the bearings ( 3 . 4 ; 12 . 13 ) upstream and downstream of the exhaust stream ( 5 . 5a ) in the housing ( 2 ) are held. Storage device according to one of the preceding claims, characterized in that the bearings ( 3 . 4 ) consist of a high temperature resistant adhesive element and / or a wire knit ring, wherein this with the ceramic catalyst ( 1 ) and / or the housing is soldered. Storage device according to one of the preceding claims, characterized in that the floating bearing (storage 3 ) for centering either by two high temperature resistant elastic adhesive elements or by a wire knit ring or cushion with sliding seat. Storage device according to one of the preceding claims, characterized that the adhesive element ( 3 . 4 ) has a composition that absorbs a temperature up to a maximum of 1700 ° C. Storage device according to one of the preceding claims, characterized in that the bearings ( 12 . 13 ) of the ceramic catalyst ( 1 ) on the housing ( 2 ) and on the ceramic catalyst ( 1 ) soldered elastic molded parts ( 14 . 15 ), which are arranged circumferentially annular around. Storage device according to claim 9, characterized in that the molded parts ( 14 . 15 ) of the bearings ( 12 . 13 ) in cross-section consist of a profile, and at least one of them gas-tight sealing between the housing ( 2 ) and the catalyst ( 1 ) are arranged.