DE102006015657B4 - Method for producing exhaust gas-conducting devices, in particular exhaust gas purification devices - Google Patents

Abstract

Method for producing exhaust-gas-conducting devices, in particular exhaust-gas cleaning devices, each having an outer housing (14) with an insert clamped therein, the insert comprising a substrate (10) through which the exhaust gas flows and an elastic compensation element (12) surrounding the substrate (10), characterized by the following steps: a) each compensating element (12) is individually deformed in a predetermined manner by exerting a pressure, wherein only a partial region (26) of the compensating element (12) is loaded, b) from the values determined thereby the desired deformation of the compensating element (12 c) the compensating element (12) is placed around the substrate (10); and d) the insert thus obtained is mounted in an outer housing (14) whose internal dimensions accomodate the outer dimensions of the insert correspond to the determined nominal deformation.

Description

The invention relates to a method for producing exhaust gas-carrying devices, in particular exhaust gas cleaning devices, each having an outer housing and an insert clamped in the outer housing, wherein the insert comprises an exhaust gas-flowed substrate and an elastic compensation element surrounding the substrate.

The exhaust gas-carrying devices which are involved in the invention are, for example, mufflers, but in particular exhaust gas purification devices, such as catalysts and particle filters.

In such devices very sensitive inserts are accommodated against radial pressure, so far it is predominantly to axially flowed through ceramic substrates, which are wrapped with an elastic compensation element (for example in the form of a mat). These inserts are, if possible, held only by radial clamping in the outer housing in the axial and radial directions. The clamping must be large enough so that in driving operation by the gas pressure or vibration no displacement of the insert relative to the outer housing in the axial direction is established. On the other hand, of course, the radial pressure must not be so great that it will destroy the insert, especially for destroying the pressure-sensitive catalyst substrate or particulate filter substrate. There are now efforts to install depositors with lower mass, which heat up faster when driving. Such substrates consist for example of a corrugated cardboard-like support structure, which is coated with catalyst material.

The insertion and clamping of the insert in the outer housing is usually done either by winding a sheet metal jacket around the insert, by inserting the insert into a tube with or without subsequent calibration or closing of trays. If the applied force is too large, it can lead to the destruction of the inserter, that is to say in the case of catalysts or particle filters of the substrate.

The DE 603 05 764 T2 discloses a method of making a catalyst in which first a set pressure is applied to the compensating element wound around the substrate to determine a set radius of the insert and compensating element insert corresponding to the desired set pressure. Subsequently, the insert is pushed into a housing with a larger diameter and the housing diameter reduced so far that its inner radius corresponds to the desired radius.

From the EP 1 445 443 A1 For example, a method for the production of a catalyst is known in which the outer dimensions of the substrate and the density of the bearing mat are determined. Subsequently, the mat is wound around the substrate and provided in its dimensions adapted to the determined values housing in which the insert of substrate and mat is mounted.

A great difficulty in manufacturing exhaust gas purification devices is that between the substrate and the outer housing, the elastic compensation element, typically the bearing mat, is provided, which ensures a pressure equalization and a constant bias. The disadvantage of this bearing mat, however, is that, after it is compressed, it is subjected to a certain setting process, one speaks of relaxation, so that the pressure passed through it to the substrate decreases. The springback of the outer housing after insertion and clamping also causes the initially applied pressure on the substrate and thus the applied clamping force to decrease. Furthermore, the holding pressure of the bearing mat decreases during operation (for example, due to aging). As a result, with regard to the subsequent secure clamping of the substrate in the outer housing, the outer housing can exercise even more initial pressure on the inserter, which is why the limits of stability are at hand for individual substrates.

The object of the invention is to provide a method which ensures a sufficiently secure clamping in the outer housing at minimal reject rates even with very pressure-sensitive inserts.

This is achieved by the following method steps: First, each compensating element is individually deformed in a predetermined manner by exerting a pressure, wherein only a portion of the compensating element is loaded. From the values determined thereby, the desired deformation of the compensating element, which is necessary to achieve a setpoint pressure, is determined. Subsequently, the compensation element is placed around the substrate and the insert thus obtained is mounted in an outer housing, the inner dimensions of which correspond to the outer dimensions of the insert in the determined nominal deformation.

In the previously known method, the outer housing is plastically deformed by a predetermined path with a constant, predetermined force, regardless of the load capacity of the currently installed insert. The invention takes a different approach by first determining the actual necessary compression of the bearing mat to then tune the outer housing to the clamping force necessary to achieve the desired Compression is necessary. Therefore, in the uninstalled state, that is to say before the winding around the assigned substrate, a force and thus a corresponding pressure are exerted on each bearing mat, for example by means of a punch. Since in this case the bearing mat is affected, both by breaking and by aligning fibers, which reduces the pressure exerted by the mat, it is provided according to the invention to burden only a portion of the mat. In this way, the "damage" of the elastic compensation element is kept as low as possible. Another advantage of an only proportionate measurement of the pressure-deformation characteristic is that, compared to a very large measuring surface, angular errors of the measuring device (for example due to a non-full-surface support of the measuring ram) are of less importance.

According to a first embodiment of the invention, it is provided that a predetermined pressure is exerted on each compensating element and the desired deformation is determined by measuring the elastic deformation of the compensating element at least when the predetermined pressure is reached. Thus, an increasing pressure is applied and at least meanwhile measured how much the compensating element elastically deforms during the pressure being exerted. Since the elastic deformation is mat specific, slightly different deformation values will be determined for each compensation element. The desired deformation at which the compensation element exerts the desired pressure can then be determined in two different ways. In this case, the target pressure is a predetermined pressure, which, depending on the required holding pressure, more or less just below the pressure value, from which the depositors are plastically deformed and thus destroyed.

A first variant for determining the set deformation provides for each compensating element to be acted upon by the setpoint pressure in order to determine therefrom the setpoint deformation and thus the outer dimensions of the insert for reaching the setpoint pressure.

After the desired deformation has been determined for the special compensation element, the corresponding inner dimensions of the applied to the insert outer housing can be determined without any special effort.

In the final method step, the outer housing with those inner dimensions is then applied to the prefabricated unit of substrate and compensating element, which correspond to the outer dimensions of the insert when the nominal deformation is determined. In other words, with the measuring device by means of which the pressure is applied to the compensating element, the subsequent pressure of the outer casing is simulated, and subsequently the outer casing is first produced or selected according to the measured values.

According to a second, particularly preferred variant for determining the nominal deformation, it is provided that the predetermined applied pressure is below the target pressure to be achieved. The desired deformation, which is necessary to achieve this target pressure, is then determined in a controller. This is done by extrapolating the deformation of the compensating element measured during the application of the pressure in order to arrive at the desired deformation. The deformation can be measured continuously with increasing pressure. Alternatively, it can of course only be measured at some specific pressure values, and then extrapolated.

This variant, in which the applied pressure is preferably well below the target pressure, offers the advantage over the former method (compensating element is already subjected to the target pressure) that a pressure loss due to multiple compression of the compensating element is avoided or at least limited. In this regard, it has been found, as already mentioned, that the usually provided mat is subject to a certain setting process, ie a plastic deformation, with each compression, as a result of which the holding pressure exerted by the mat also decreases. Now, if the bearing mat in a corresponding measuring device (possibly even several times) applied to the target pressure and determines the desired deformation, then a subsequent secure clamping of the insert in the outer housing, which is designed for just this nominal deformation, may no longer be guaranteed, because the holding pressure of the mat has decreased due to the multiple compression. Incidentally, a similar pressure loss also occurs when the mat is "over-compressed" to compensate for possible springback of the outer housing, that is, beyond the setpoint pressure. However, if only one lying below the target pressure pressure exerted on the compensating element, which is just sufficient to extrapolate the (further) course of the pressure-deformation curve with sufficient accuracy, the effect described can be avoided or at least greatly reduced.

Alternatively to the exercise of a predetermined pressure on the compensating element and measurement of the deformation caused thereby, it is also possible to cause the compensating element by pressurization a predetermined deformation and to determine the desired deformation in that at least the Reaching the predetermined deformation necessary pressure is measured on the compensating element. This predetermined deformation may be a deformation by a certain amount (ie the variable thickness of each compensating element within certain limits is reduced by a constant, predetermined value) or a deformation to a predetermined value, namely a predetermined thickness, act. Under a measurement of the pressure in this context, of course, a measurement of the required force, for example by means of a load cell to understand, from which then (taking into account the surface of the load cell) can be directly closed to the pressure.

A particularly preferred embodiment of the invention also provides here that the predetermined deformation is below the desired deformation and the target deformation is extrapolated due to the pressure exerted at the predetermined deformation. The predetermined deformation is to be chosen as low as possible; Advantageously, it is just large enough to allow a sufficiently accurate extrapolation of the pressure-deformation behavior of the special compensating element. Thus, the already described in connection with the pressure-controlled method pressure loss is avoided by multiple compression of the compensating element or at least limited.

In order to further optimize the subsequent clamping of the insert in the outer housing, additional parameters can be taken into account during the extrapolation. In particular, here are the e.g. occurring in wound casings spring back of the outer housing after the closing process or occurring after assembly expansion of the housing (in the case of a prefabricated cylindrical outer housing into which the insert is inserted) to call. Furthermore, it is advantageous to take into account the change in shape of the outer housing which occurs during temperature changes which are unavoidable during operation of the exhaust gas purification device; straight casings with non-round cross-section tend to "round". If this tendency is taken into account in the determination of the individually tailored outer housing for the respective depositor, for example by making an oval housing somewhat longer, local pressure peaks in the areas of smaller radius can be avoided. In this way results in a lower substrate load, which has less waste and a better durability.

According to the preferred embodiment, in addition to determining the nominal deformation of the compensating element, the individual outer geometry of the substrate is determined, which is also included in the calculation of the housing geometry.

For this, the substrate is e.g. measured, which can be done with the help of a camera, by laser measurement or by mechanical means.

In particular, the portion of the compensating element deformed by the application of pressure is a continuous area. Alternatively, it is also possible to carry out the compressibility measurement using a plurality of small measuring surfaces.

In order to minimize measurement-related damage to the compensating element, the area of the portion should be less than half, preferably between 15 and 25%, of the surface of the compensating element. In the case of a catalyst whose bearing mat is about 400 mm long and 100 mm wide, offers a measuring area of about 100 mm * 100 mm (or a comparable non-square area) at. In the case of a particle filter whose bearing mat has the dimensions 300 mm * 400 mm, a measuring area of (150 mm) ² provides a sufficient accuracy.

In order to avoid measurement errors due to edge or cutting effects, the subregion in which the pressure measurement takes place should be a region of the compensating element which is remote from the edge, in particular the middle region.

As already mentioned, the device produced by the method according to the invention is, according to the preferred embodiment, an exhaust gas catalyst or a particle filter, both of which are provided with a labile substrate as the core of the insert. A combination of catalyst and particle filter is possible.

The housing is designed in particular as a sheet-metal housing, and the compensation element is in particular a bearing mat.

The method according to the invention can be applied to all hitherto known methods for producing exhaust gas-conducting devices.

A first method is the so-called winding, in which a plate-shaped sheet metal section is wound around the insert and then fastened and closed at its edges after reaching the predetermined internal dimensions.

A second method is the calibration, is pressed against the outside of the circumference of the prefabricated tube against this to plastically deform and press against the insert.

A third method involves a shell made up of several shells that bear against the depositor pressed and then attached to each other.

A fourth embodiment provides a so-called stuffing method. Here, several cylindrical housing with different internal dimensions are prefabricated. By the method according to the invention, the inner dimensions of the housing are determined so that provide the desired pressure. Then then the housing can be used with the appropriate dimensions to insert the end face of the insert into the housing. Alternatively, the housing can be custom-made with the optimum diameter determined in the pressure or displacement measurement and calculation.

• - 1 eine Längsschnittansicht durch eine durch die Erfindung hergestellte Vorrichtung in Form einer Abgasreinigungsvorrichtung,
• - 2 schematische Ansichten von beim erfindungsgemäßen Verfahren verwendeten Meßvorrichtungen und Werkzeugen;
• - 3 ein Druck-Verfahrweg-Diagramm, das für das erfindungsgemäße Verfahren charakteristisch ist;
• - 4 in Draufsicht verschiedene elastische Ausgleichselemente, bei denen der Teilbereich für die Druckbelastung markiert ist;
• - 5 eine stirnseitige Ansicht einer durch das erfindungsgemäße Verfahren hergestellten Vorrichtung, wobei das Außengehäuse gewickelt ist;
• - 6 eine perspektivische Ansicht eines beim erfindungsgemäßen Verfahren eingesetzten Kalibrier-Werkzeugs, teilweise im Schnitt ;
• - 7 eine stirnseitige Ansicht einer durch das erfindungsgemäße Verfahren hergestellten Vorrichtung mit einem aus Schalen hergestellten Außengehäuse; und
• - 8 eine Prinzipskizze, die das beim erfindungsgemäßen Verfahren alternativ angewandte Stopfen zeigt.

Further features and advantages of the invention will become apparent from the following description and from the following drawings, to which reference is made. In the drawings show:

• - 1 a longitudinal sectional view through an apparatus produced by the invention in the form of an exhaust gas purification device,
• - 2 schematic views of measuring devices and tools used in the method according to the invention;
• - 3 a pressure-travel diagram that is characteristic of the method according to the invention;
• - 4 in plan view different elastic compensation elements, in which the portion is marked for the pressure load;
• - 5 an end view of a device produced by the inventive method, wherein the outer housing is wound;
• - 6 a perspective view of a calibration tool used in the method according to the invention, partly in section;
• - 7 an end view of a device produced by the method according to the invention with an outer casing made of shells; and
• - 8th a schematic diagram showing the alternatively used in the inventive method plug.

In 1 is shown housed in a motor vehicle exhaust-carrying device in the form of an exhaust gas purification device. The exhaust gas purification device is either an exhaust gas catalyst or a particulate filter or a combination of both.

The core of the exhaust gas purification device is an elongate, cylindrical substrate 10 , which consists for example of a ceramic substrate or a type of wound corrugated cardboard or other catalytic carrier or filter material with or without coating. The substrate 10 may have a circular cylindrical cross section or a non-circular cross section. For the sake of simplicity, a circular-cylindrical cross-section is shown in the figures. The substrate is from a storage mat 12 surrounded, as an elastic compensation element between the substrate 10 and an outer casing 14 acts. The outer housing 14 is very thin-walled and in particular made of sheet metal. Upstream and downstream are with the outer casing 14 an inflow funnel 16 or a discharge funnel 18 connected.

The substrate 10 forms together with the storage mat 12 a unit, hereinafter referred to as inserter.

During operation, exhaust gas flows over the inlet funnel 16 frontally into the substrate 10 Finally, leaving the substrate with fewer pollutants leaves 10 on the opposite front side, over the discharge funnel 18 leave the cleaning device.

The preparation of the exhaust gas purification device will be described below with reference to 2 to 5 explained.

In 2 Different measuring stations are shown with which properties of each individual substrate 10 and every storage mat 12 with regard to an individually matched outer housing for achieving an optimized clamping force of the insert in the outer housing 14 be determined. The measuring stations are via a controller 20 with tools for the production of the outer housing 14 or for mounting and clamping the insert in the outer housing 14 coupled. The stations explained below are described in the preferred order of the manufacturing process.

In a first measuring device 22 becomes the outer geometry (shape and outer dimensions, in particular circumference) of the substrate 10 determined by means of preferably non-contact measuring sensors. The measuring device 22 is with the controller 20 connected, in which the obtained measured values for the substrate are stored. Alternatively, to determine the outer geometry and a CCD camera 22 ' or a laser measuring device 22 " Find application.

In a train-pressure testing machine 24 becomes the storage mat 12 by a stamp 25 increasingly under pressure in one subarea.

This is the on the storage mat 12 applied force steadily increased until reaching a predetermined pressure. During the procedure of the stamp 25 is the point of time or continuously recorded the distance parallel to the pressure. From the contacting of the bearing mat 12 until the position of the stamp 25 when reaching the predetermined pressure, for example, a travel X is determined. In this case, the predetermined pressure may be the desired pressure corresponding to the setpoint deformation, with which later the insert in the outer housing 14 should be clamped.

However, it is preferably, as previously explained, significantly below the target pressure p _s terminate the measuring process and up to the predetermined, lower predetermined pressure po the punch 25 on the storage mat 12 to move over the previously determined measurement parameters on the travel (and thus the required target deformation) to achieve the desired pressure ps up-calculate. This is the train-pressure testing machine 24 also with the controller 20 coupled.

3 schematically shows the course of the on the bearing mat 12 applied pressure p as a function of (actual or calculated) travel X. As already mentioned, is applied to the bearing mat 12 through the stamp 25 only the pressure po exercised, the one traversing X ₀ of the stamp 25 equivalent. The value po is previously determined depending on the materials used for the inserter and is constant for all components of a series. During the movement of the stamp 25 be several measurements for the pressure p as a function of the travel X to the controller 20 to hand over. From these for every storage mat 12 Specific measured values become the further course of the pressure-travel characteristic for the respective bearing mat 12 extrapolated. This will also the subsequent springback of the outer housing 14 and possibly other parameters considered, why the target pressure p _s (arithmetically) is increased by an amount Δp. In this way you get to the through the outer housing 14 applied pressure p _A that a travel path X _A of the stamp 25 equivalent. This travel path X _A sets the nominal deformation of the bearing mat 12 firmly.

For extrapolation of the pressure-displacement characteristic curve, instead of the pressure po, the travel path Xo of the punch 25 for the respective series to be set to a constant value, again when moving the stamp 25 the pressure p is measured as a function of travel X and to the controller 20 is transmitted.

4 shows various examples of bearing mats 12 , where by the stamp 25 charged partial areas 26 hatched are shown. In the subarea 26 it can be a contiguous area ( 4a, b . d ) or several individual areas ( 4c ) act. All examples have in common that the loaded portion of a spaced-edge, central region of the bearing mat 12 is. In particular, it is therefore not in the area of the bearing mat 12 arranged in the assembled state of the bearing mat 12 whose front edges abut (cf. 4d ). The proportion of the loaded partial area on the total area of the storage mat 12 is about 15 to 25%.

With the determined data on the insert to be installed (consisting of substrate 10 and storage mat 12 ) is in control 20 one on at least the compressibility of the bearing mat 12 coordinated geometry of the outer housing 14 determines what by calculating or comparing with one in the controller 20 filed allocation matrix can be done. The individual geometry is designed to achieve the required, individually tailored to the depositor and exercising clamping force.

In a next step, this determined outer housing 14 with tuned geometry, for example by incremental forming (see position 27 in 2 ). This can be done by mandrel or roll bending, but the bending roll must be very small dimensions in order to produce the necessary small transformations can.

Subsequently, the compensation element in the form of the bearing mat 12 around the substrate 10 placed, and the deposit thus obtained is in its tailor-made outer casing 14 installed in the so-called winding process (see position 28 ). This is the prefabricated outer housing 14 slightly spread and the insert laterally in the outer housing 14 inserted. The outer housing 14 is pressure and / or path controlled closed by the overlapping edges 30 . 32 so far pushed over each other that the dimensions of the resulting outer housing 14 correspond to the previously determined values. The closing process takes place on the basis of suitable, previously in the control 20 determined and on the individual substrate 10 or the storage mat 12 matched parameter. Subsequently, the overlapping edges are joined, eg welded, folded, soldered or glued. The finished product is in 5 shown.

In addition to the winding of the outer housing 14 the assembly can also be done by a so-called calibration. A corresponding calibration device is in 6 shown. This includes numerous circular segment-shaped, radially movable jaws 34 that can close to a ring. Into the inside through the cheeks 34 circumscribed workspace is the circular cylindrical tubular outer housing 14 placed in which the insert is inserted axially. The cheeks 34 are then moved radially inward, in particular those previously in the control 20 stored values with regard to the travel path X _A can be used. That means that through the controller 20 previously determined desired outer dimensions of the insert are controlled by a path-controlled movement of the jaws 34 with simultaneous plastic deformation of the outer housing 14 reached. The prerequisite is, of course, that the insert before deformation almost free of play in the outer housing 14 was positioned or the game was taken into account in the deformation. The through the plastically deformed outer housing 14 The pressure applied to the inserter thus corresponds (after springback) to the target pressure p _s ,

Instead of in 6 shown baking 34 the calibration can also be carried out by means of rollers, which laterally around the predetermined travel path against the outer housing with insert provided therein X _A be pressed and turned. Also a so-called pressing is possible in this context, in which the outer housing 14 with insert disposed therein relative to the predetermined travel path X _A is moved against a single roller and then a relative rotation between the roller and the outer housing together with insert, so that the roller presses circumferentially in the outer housing and this plastically to the travel X _A deformed to the inside.

In the 7 embodiment shown operates with two or more shells 35 . 36 which are pushed together. Again, the shells 35 . 36 moved away as far as pushed together until the inner dimensions correspond to the specific outer dimensions of the insert. The bowls 35 . 36 then z. B. welded together, folded or soldered. Again, a springback or expansion compensation is to be included.

8th shows schematically the so-called plug. In the measuring device, the desired outer dimensions of the insert are determined. Subsequently, a cylindrical, tubular outer housing 14 manufactured with the desired diameter. This calibration can be done in one or more work cycles or in a continuous process (eg rolling). Subsequently, the insert is axially in the selected outer housing 14 stuffed. Of course, corresponding funnel-shaped aids or aids for radial precompression are provided. The expansion of the outer housing during the stuffing process 14 is compensated analogously to the procedure described for the springback when determining the nominal deformation.

The method according to the invention offers numerous advantages. So z. As an applicability is also given in non-circular cross-section substrates, such as oval or so-called tri-oval substrate diameters. In the pressure load of the flat mat is (in contrast to a pressure load of the entire insert) no twisting or tilting possible. In addition, a quality inspection of the mat is performed simultaneously. By determining the substrate geometry, a geometric examination of the substrate is also included in the process. Thus, the additional testing effort can be reduced. The inventive method can control the functional parameter pressure and achieve improved process accuracy and repeatability. There is achieved an improved quality of the produced exhaust gas purification device; in particular, the method is suitable for so-called ultrathin wall substrates.

It should be emphasized that the illustrated method is not intended for experimental purposes where a single catalyst or particulate filter is made. Rather, the method is just meant for mass production, in which each individual bearing mat is previously loaded and measured for pressure.

LIST OF REFERENCE NUMBERS

10

substratum

12

bearing mat

14

outer casing

16

inflow funnel

18

outflow funnel

20

control

22

measuring device

22 '

CCD camera

22 "

laser measuring device

24

Train-pressure testing machine

25

stamp

26

subregion

27

forming tool

28

winder

30, 32

margins

34

to bake

35, 36

Peel

Claims (18)

Method for producing exhaust gas-conducting devices, in particular Exhaust gas purification devices, each having an outer casing (14) with an insert clamped therein, the insert comprising a substrate (10) through which exhaust gas flows and an elastic compensating element (12) surrounding the substrate (10), characterized by the following steps: a) each compensating element ( 12) is individually deformed in a predetermined manner by exerting a pressure, wherein only a portion (26) of the compensating element (12) is loaded, b) from the values determined thereby, the desired deformation of the compensating element (12), which is necessary to achieve a desired pressure is determined, c) the compensation element (12) is placed around the substrate (10), and d) the insert thus obtained is mounted in an outer housing (14) whose internal dimensions correspond to the outer dimensions of the insert at the determined set deformation. Method according to Claim 1 characterized in that a predetermined pressure is exerted on each compensating element (12) and the desired deformation is determined by measuring the elastic deformation of the compensating element (12) at least when the predetermined pressure is reached. Method according to Claim 2 , characterized in that the predetermined, applied pressure is the pressure at which the insert is subjected to the setpoint pressure. Method according to Claim 2 , characterized in that the predetermined, applied pressure is below the target pressure and the target deformation is extrapolated due to the deformation in the application of the predetermined pressure. Method according to Claim 1 , characterized in that in the compensating element (12) caused by pressurization a predetermined deformation and the desired deformation is determined by that at least the pressure necessary to achieve the predetermined deformation pressure on the compensating element (12) is measured. Method according to Claim 5 , characterized in that the predetermined deformation is below the target deformation and the target deformation is extrapolated due to the pressure exerted at the predetermined deformation. Method according to Claim 4 or Claim 6 , characterized in that in the extrapolation at least one of the following parameters is taken into account: springback of the outer housing (14), widening of the outer housing (14), change in shape of the outer housing (14) with temperature changes. Method according to one of the preceding claims, characterized in that in addition to determining the nominal deformation of the compensating element (12), the individual outer geometry of the substrate (10) is determined. Method according to Claim 8 , characterized in that the substrate (10) for determining the individual outer geometry is measured. Method according to one of the preceding claims, characterized in that the part region (26) of the compensating element (12) which is deformed by exertion of a pressure is a contiguous region. Method according to one of the preceding claims, characterized in that the area of the partial region (26) is less than half the area of the compensating element (12). Method according to one of the preceding claims, characterized in that the partial region (26) is a region of the compensating element (12) remote from the edge. Method according to one of the preceding claims, characterized in that the device is an exhaust gas catalyst or a particulate filter or a combination of both. Method according to one of the preceding claims, characterized in that a sheet-metal housing is used as outer housing (14). Method according to one of the preceding claims, characterized in that the outer housing (14) is produced by winding around the insert. Method according to one of Claims 1 to 14 , characterized in that the outer housing (14) is pressed by calibrating against the insert. Method according to one of Claims 1 to 14 , characterized in that the outer housing (14) consists of a plurality of shells (35, 36) which are pressed against the insert and secured together. Method according to one of Claims 1 to 14 , characterized in that the insert in a prefabricated cylindrical outer housing (14) is stuffed, the inner dimensions of which correspond to the determined outer dimensions of the insert.

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