EP1628789B1 - Production of a structured sheet metal for devices for treating exhaust gas - Google Patents

Description

The present invention relates to a method and an apparatus for producing a structure in a smooth sheet-metal strip, which is used in particular for the production of exhaust gas treatment devices of mobile internal combustion engines.

In the exhaust treatment of mobile internal combustion engines, such. As gasoline and diesel engines, it is known to arrange components or structures in the exhaust pipe, which provide a relatively large surface area. These components are usually provided with an adsorbing, catalytically active or other coating, wherein due to the large surface area of the components an intimate contact with the passing exhaust gas is realized. Such components are, for example, filter elements for filtering out particles contained in the exhaust gas, adsorbers for at least temporary storage of pollutants contained in the exhaust gas (for example NO _x ), catalytic converters (for example three-way catalyst, oxidation catalytic converter, reduction catalytic converter, etc.), diffusers for influencing the flow or turbulence of the exhaust gas flowing through, or also heating elements which heat the exhaust gas to a desired temperature just after the cold start of the internal combustion engine. With regard to the conditions of use in the exhaust system of an automobile, the following carrier substrates have proven successful in principle: ceramic honeycomb bodies, extruded honeycomb bodies and honeycomb bodies made of metal foils. Due to the fact that these carrier substrates are always to adapt to their functions, high-temperature-resistant and corrosion-resistant metal sheets are particularly well suited starting materials for the production.

It is known to produce honeycomb bodies with a plurality of at least partially structured sheets, which are subsequently introduced into a housing and thus form a carrier body which can be provided with one or more of the above-mentioned coatings. The at least partially structured sheets are arranged so that substantially parallel to each other arranged channels are formed. To ensure this, for example, a part of the sheets is provided with a primary structure, which is characterized inter alia by a regular, repetitive structure, in particular a kind of sine wave structure, a sawtooth structure, a rectangular structure, a triangular structure, an omega structure od. Like. These sheets provided with the structure are then stacked (possibly alternately with smooth liners), wound together and inserted into a housing. Thus, a honeycomb body is formed, which has substantially parallel channels.

Further, it is known to introduce a second structure in such sheet metal foils, which are intended in particular to prevent a laminar flow forms immediately after the entry of the exhaust gas into the honeycomb body, wherein a gas exchange of lying in the center of such a channel areas of the partial exhaust gas stream with the z. B. catalytically active channel wall areas does not take place. This secondary structure or microstructure provides inflow surfaces, which entail a turbulence of the partial exhaust gas streams in the interior of such a channel. This leads to an intensive mixing of the partial exhaust gas streams themselves, so that an intimate contact of the pollutants contained in the exhaust gas is ensured with the channel wall. Furthermore, it is possible to form through these secondary structures flow passages across the channel, which allow gas exchange of partial exhaust gas streams in adjacent channels. For this reason, secondary structures are known, which include, for example, guide surfaces, microstructures, nubs, protrusions, wings, tabs, holes or the like. In this respect, there is a significantly increased variety of variations in the production of such metallic honeycomb body compared to those made of ceramic material, because such complex channel walls can not be realized or only with very high technical complexity.

Furthermore, it is of particular interest in the exhaust gas treatment that an implementation of the pollutants contained in the exhaust gas takes place almost immediately after the start of the engine. This should take place in accordance with the statutory provisions or guidelines with a particularly high level of effectiveness. For this reason, ever thinner metal foils or sheets have been used in the past. Very thin sheets represent a very low surface specific heat capacity, i. h., That the passing exhaust gas relatively little heat is removed or the sheets themselves relatively quickly experience a temperature increase. This is important because the catalytically active coatings currently used in the exhaust system begin only at a certain light-off temperature with the implementation of the pollutants, which is approximately at 230 ° C to 270 ° C. With the aim of implementing these pollutants after only a few seconds with an at least 98% effectiveness, sheets are used which have a film thickness, for example, less than 50 microns (0.05 mm), in particular even less than 30 microns (0.03 mm).

For the above objectives, however, result in a number of manufacturing and application problems. The production of such filigree structures, in particular the secondary structures or microstructures, requires particularly precise working tools, which are usually very expensive and should therefore realize long service lives. It should be noted that on the one hand reshaping and on the other hand, if necessary, separating manufacturing steps must be accomplished. In order to save tooling costs, as many processing steps as possible have been integrated into a tool, whereby due to the shape of the secondary structure, an increasing wear on the tool is observed. Furthermore, there is the problem that the relatively thin sheet metal foils must be fed at a suitable speed, if possible to be exposed without undesirable cold deformation. The strain hardening can adversely affect the forming behavior of the sheets.

Due to the use of relatively thin sheets there is also the risk that the metal foils tend to wrinkle during manufacture, for rolling up and / or tearing. These undesirable deformations can occur or even increase in the production, as well as during transport or during use in an exhaust system of an automobile. For example, the wrinkles result in u. Ducts are clogged or cracks are formed, which propagate because of the high thermal and dynamic loads in the exhaust system of an automobile and jeopardize the structural integrity of the honeycomb body. Furthermore, it should be taken into account that such crumpled or deformed primary and / or secondary structures oppose the exhaust gas in an undesired manner, so that an increased back pressure upstream of the honeycomb body is to be feared, which may possibly lead to a reduction in engine performance.

From the US 5,599,509 a honeycomb body or a catalyst is known, wherein a smooth sheet metal strip is processed by a punching tool and a corrugated tool and subsequently wound. Holes and corrugated structure are arranged independently of each other, so that a coordination of the tools to each other is not necessary.

Furthermore, a device in DE 41 30 673 A1 discloses, which structures a sheet metal strip by means of a punching tool and a corrugated tool, wherein between the two tools, a further feed is arranged, which engages in the introduced holes and feeds the sheet metal strip to the corrugated tool.

US 1,495,637 describes a metal strip forming machine which first introduces structures and subsequently holes in a sheet metal strip, wherein drive rollers in front of and behind the tools to produce the feed.

On this basis, it is an object of the present invention to provide a method and an apparatus for producing structured sheets, which ultimately can withstand the high thermal and dynamic loads in the exhaust system of an automobile permanently. In particular, the technical problems mentioned at the outset are to be overcome by producing a very uniform configuration of the primary structure or secondary structure, so that errors during production can be minimized. At the same time the possibility should be created to reduce the influence of inhomogeneities of the sheet metal strip used as a half tool in the production of such sheets in series production. In addition, a particularly space-saving device should be specified.

These objects are achieved by a method for producing a structure in a smooth sheet-metal strip according to the features of patent claim 1 or by an apparatus for producing a structure in a smooth sheet-metal strip with the features of claim 7. Further advantageous embodiments of the method and the device are described in the respective dependent claims. In addition, it should be noted that the features mentioned in the claims can be combined with each other in any meaningful way and possibly supplemented by facts of the description.

1. a) Zuführen eines ersten Abschnittes eines glatten Blechbandes zu einem ersten Werkzeug und eines zweiten Abschnittes des Blechbandes zu einem zweiten Werkzeug in einer Vorschubrichtung;
2. b) Anhalten des Blechbandes;
3. c) Durchführen einer Blechbearbeitung des ersten Abschnittes des Blechbandes mit dem ersten Werkzeug;
4. d) Durchführen einer Blechbearbeitung des zweiten Abschnittes des Blechbandes mit dem zweiten Werkzeug, wobei gleichzeitig Schritt a) ausgeführt wird.

The inventive method for producing a structure in a smooth sheet-metal strip comprises at least the following steps:

1. a) feeding a first portion of a smooth sheet metal strip to a first tool and a second portion of the sheet metal strip to a second tool in a feed direction;
2. b) stopping the sheet metal strip;
3. c) performing a sheet metal working of the first portion of the sheet metal strip with the first tool;
4. d) carrying out a sheet metal working of the second portion of the sheet metal strip with the second tool, wherein at the same time step a) is performed.

In this case, step c) comprises the introduction of at least one hole in the first section and step d) generates a structure in the second section of the sheet-metal strip, wherein the second section is already provided with at least one hole.

In addition, the second tool engages during the step d) in the at least one hole.

In addition, the sheet metal strip is clamped by means of the second tool and a, the first tool prefixed, holding device.

Usually, the sheets, which are ultimately used in exhaust gas treatment plants of automobiles, made of a metal strip, the sheets are finally separated according to the desired length of the metal strip. The sheet metal strip consists of a high-temperature-resistant and corrosion-resistant material. The material is based on iron and has at least one of the components aluminum, chromium and nickel. While the sheet metal strip has a length of many meters, the width of the sheet metal strip substantially already corresponds to the desired width, as required for the exhaust system. Usually, the width is in the range of less than 15 cm. The sheet metal strip is usually rolled into a coil and is fed via conveyors.

Due to the fact that two processing steps take place in succession, different sections of the sheet metal strip are processed in each case. The first section of the smooth sheet-metal strip is first processed by the first tool and finally fed to the second tool. Hereby, a step is described in which due to the spatial separation of the first tool and the second tool (edited by the first tool) first section is not directly supplied to the second tool, but this second tool processed another (second) section of the sheet metal strip. The second section may have already been processed by the first tool, but it is also possible that the second section still includes a smooth area of the sheet metal strip. The sections preferably extend over the entire width of the sheet metal strip and have a section length which is essentially oriented to the structure to be produced. Preferably, the section length of the first section and the second section is the same. The section on the smooth sheet-metal strip essentially corresponds to the working area of at least one tool. Tool is a generic term for various devices, apparatus, etc. specified for sheet metal forming.

Due to the fact that the sheet-metal strip is continuously integrally formed, according to step a), the first section is transported to the first tool and a second section to the second tool in the desired feed direction at the same time. After step a) is thus in each case a portion of the sheet metal strip near the respective tool, which has not been processed by the first or second tool. Preferably, this first section or second section directly adjoins the section of the sheet metal strip that has just been processed in the feed direction.

If this supply of the sheet metal strip was made in the desired position, the sheet metal strip according to step b) is stopped. Thus is ensures that no relative movement of the sheet metal strip takes place to the tools, while the following step c) is performed.

Now, a sheet metal processing of the first portion of the sheet metal strip is performed with the first tool (step c)). The "sheet metal processing" includes in particular sheet metal forming and separating manufacturing processes. Sheet metal transformations are characterized in particular in that the sheet metal strip is formed into planar hollow parts or structures, wherein after the processing step a substantially uniform material thickness is present, as it has been present before the processing step. This applies, for example, to the production processes of drawing, pressing, bending, etc. Other forming manufacturing processes can be hydroforming, superplastic forming, magnetic forming, etc. Under a sheet metal processing are also subsumed here methods for sheet separation, such as cutting or fine cutting, laser beam cutting, the water-abrasive jet cutting, etc.

After the sheet metal working of the first section is substantially completed, step d) is carried out, in which a sheet metal processing of the second section takes place with the second tool. Simultaneously with the sheet metal working of the second section, step a) is carried out again, that is to say a (new) first section is fed to the first tool and a (new) second section is fed to the second tool. In other words, in this two-stage machining, the first machining step is carried out with the sheet metal strip resting, while the second machining step takes place simultaneously with a relative movement of the sheet metal strip to the tools. Ie. also that step d) and step a) are superimposed in time. This has the consequence that a precise and precise for the sheet metal processing with the second tool precise feeding of the sheet metal strip is made possible. In particular, the sheet metal processing with the second tool is such that it automatically generates a relative movement of the sheet metal strip to the second tool.

In addition to the particularly precise feeding of the first section or of the second section to the respective tool, the combination of steps d) and a) simultaneously opens up a particularly rapid processing, so that very high feed rates of the sheet-metal strip can be realized. For a series production of such structured metal bands, for example, feed speeds above 10 m / min (meters per minute) can be realized, in particular also over 12 m / min or even 15 m / min. Especially with less complex structures even feed speeds above 25 m / min or even over 50 m / min can be achieved.

In the method according to the invention, step c) comprises the introduction of at least one hole in the first section and step d) creates a structure in the second section of the sheet metal strip, the second section is already provided with at least one hole. In other words, that means here Overlay the two sheet metal forming steps takes place. The second section, which is here provided with a structure, was thus previously processed by a sheet-metal separating process. In this context, it should be pointed out that here the term "hole" is again as a generic term for a introduced into the metal strip separating edge of any shape, in particular a slot, an opening, a slot, a rectangle, etc .. In that If, for example, a plurality or multiplicity of such holes is already in the second section, the forming behavior of the sheet-metal strip is locally considerably influenced. Therefore, step d) is adapted accordingly. This can be ensured, for example, via the type of introduction of the structure or a special configuration of the second tool. Due to the fact that the at least one hole is very small compared to the entire second section, a very precise alignment of the hole is required to the second tool, which is made possible in particular by the combination of steps a) and d).

In addition, the second tool engages during the step d) in the at least one hole. The intervention of the second tool is to be understood in particular as meaning that sheet metal forming takes place in the immediate vicinity of the hole, so that the area of the sheet metal strip adjacent to the hole is deformed. The second tool can thus rest on the hole after forming and / or penetrate it at least partially. This also means, inter alia, that the second tool and the section previously processed by step c) form a form fit when performing step d). Precisely with such a method or, in the case of the types of primary and / or secondary structures of very small extent described here, the precise feeding of the sections to the tools is therefore also guaranteed in the context of mass production.

According to a further embodiment of the method, a structure in the second section of the sheet-metal strip is produced in step d), which has a primary structure and a secondary structure. The primary structure is preferably formed over the entire length of the sheet metal strip in a repetitive manner and advantageously also continuously in succession. The secondary structure overlays the primary structure or only extends over a spatially limited subarea of the primary structure. The secondary structure can, as already explained, include nubs, wings, edges or similar structures. The secondary structure is used u. a influencing a flow of fluid guided along the surface of the sheet-metal strip so that turbulence or calming zones arise in which, on the one hand, a type of turbulent flow or a reduced flow velocity with respect to the fluid can be produced. Concerning the implementation or design of such secondary structures is to be exemplified in WO 01/80978 A1 referenced, the content of which is fully made the subject of the disclosure

According to the method of the invention, the sheet metal strip is clamped by means of the second tool and a, the first tool prefixed, holding device. The holding device has the function, first of all, to relieve the upstream coil. In addition, the holding device ensures that the metal strip is stretched between it and the second tool as the last forming work station, so sags, compressions or the like can be avoided. This supports a particularly precise feeding of sections of the sheet metal strip to the tools. As a holding device, for example, brakes, friction linings or the like can be used.

According to a preferred embodiment of the method, step c) comprises punching a plurality of holes. The production method stamping is assigned to the sheet metal separating production method, wherein a part or a knife of a piece of the material of the sheet metal strip is separated from other parts with a cutting edge or a knife. In this case, material can be removed from the sheet-metal strip (formation of a recess, an opening, etc.) or even material only be pushed aside (as in the case of a slot, for example). It is also possible that in the first section openings and slots are introduced side by side. The formation of the plurality of holes preferably takes place in rows and in particular over the entire width of the sheet-metal strip. For this purpose, several rows of holes at the same time or offset in time can be introduced to each other.

It is also proposed that step d) comprises the corrugating of the sheet metal strip. During corrugating, the sheet metal strip is passed through two rotating, intermeshing, intermeshing profile roller. In the embodiment of the method explicitly proposed here, the corrugating rolls not only serve to produce a structure in the sheet-metal strip, but at the same time constitute the transport element with which the sheet-metal strip is conveyed or fed in a defined manner. This requires in particular that the rollers realize a feed of the sheet metal strip, in particular by generating a force in the feed direction on the sheet metal strip.

According to a development of the method, the steps a) to d) are repeated, the repetition rate being at least 5 hertz [ ¹ / second]. In particular, repetition rates above 10 Hertz or even above 20 Hertz are preferred for mass production. The repetition rate is a measure of the time intervals at which step a) is restarted. A repetition rate of 5 Hertz means that the method steps a) to d) are repeated five (5) times in one second. The one described here Method allows for the first time a very fast and accurate production of structured metal strips, even if they have very complex structures that require an alignment of a plurality of processing stations to each other, at the same time can be dispensed with additional monitoring and feeding units or Zuführantriebe.

Moreover, it is also advantageous to bring the metal strip at least before step c) in contact with a fuel. Under operating materials in this sense fall in particular oils, lubricants, coolants, etc. The supplies are intended to support the processing or transformation of the metal strip or prevent jamming, jamming of the tools.

According to a further aspect of the invention, an apparatus for producing a structure in a smooth sheet-metal strip is proposed. The device comprises at least a first tool for sheet metal processing and a second tool for sheet metal processing and is characterized in that the first tool and the second tool are arranged directly behind one another and the second tool comprises means for simultaneously carrying out a sheet metal forming and a sheet metal band feed The device in particular suitable for carrying out the method according to the invention described above.

Known devices for producing a structure in a smooth sheet-metal strip, which comprise at least two processing steps, each had a separate 'drive or a separate feed device for the processing station. The respective drives were u. U. coupled with each other via a complex electronic control to allow precise delivery to the respective workstation

Here it is now proposed that the first tool and the second tool are arranged directly one behind the other, so is dispensed with a separate feed to the tools. The second tool represents by the machining process a Blechbandvortrieb both for itself, as well as for the upstream first tool. Accordingly, the second tool pulls the metal strip into the first tool. For this purpose, the second tool on a clocked drive, each of which allows a feed in such a way that always the desired first portion is supplied to the first tool. Thus, a particularly precise supply of the sheet metal strip is created because the retraction of the sheet metal strip by the second tool (regardless of other feeders), the relative distance of the first section and the second section is always kept constant. The sheet metal forming preferably takes place simultaneously over the entire width of the sheet metal strip.

It is provided that the first tool and the second tool form a distance in a feed direction of the sheet metal strip, which is smaller than 1000 mm [millimeters]. Preferably, this distance is even less than 500 mm or even less than 200 mm. The omission of separate drives for the supply of the sheet metal strip allows a spatially very close to each other positioned first and second processing station (or tool). Ie. also, that the first sheet metal working and the second sheet metal working substantially be performed in a region of the sheet metal strip, which has only very slightly different material properties. This ensures that the sheet metal work carried out with the first tool is finally formed very precisely and precisely to the final position in the second tool. Thus, a very space-saving and precise working device is specified.

In the apparatus according to the invention further serves the first tool at least the production of at least one hole, in which engages the second tool, wherein the sheet metal strip by means of the second tool and a, the first tool verangestellten, holding device is tensioned.

It is further proposed that the first tool is a punching tool. This is used in particular for the introduction of holes, etc. in the sheet-metal strip, which subsequently allow the formation of complex structures with the second tool.

It is particularly advantageous that the punching tool has a stroke drive, which produces a working and an idle cycle This means in particular that practically a continuous drive of the punch is applied, the movement of the punching tool, however, is performed only in part of this drive cycle , For this example, eccentrics, camshafts or similar devices may be used, which temporarily cause a movement of the punching knife, on the other hand, however, have a stoppage of the punching result. The drives can be mechanical, hydraulic and / or electromagnetic type. This realizes the separation of steps c) and d) according to the method described above in a technically simple manner.

According to a further embodiment of the device, the second tool comprises meshing profile rollers. In particular, the manufacturing process corrugating is performed. The meshing profile rollers have a surface contour, which roll during the rotation substantially to each other. They preferably do not touch each other, but have a gap to each other, which is essentially the Sheet thickness of the metal strip corresponds. As a result, a particularly gentle Umformuilg the sheet metal strip is effected.

In such a device, it is particularly advantageous that the second tool has a rotary drive, which provides a rotation clock frequency of at least 5 Hertz [ ¹ / _second ]. Due to the fact that the second tool at the same time determines the feed of the sheet metal strip, that acts as a kind of transport member, the rotational clock frequency of the rotary drive substantially corresponds to the repetition rate of the machining process. The rotary drive advantageously allows even rotation clock frequencies above 10 hertz, in particular even above 20 hertz. For example, revolutions above 3,000 rpm and more may be present.

Advantageously, the device is to be designed so that at least the first tool or the second tool has a working zone that corresponds to a multiple of a width of the structure. Preferred is the embodiment that both the first tool and the second tool have the same work zone, which corresponds to a multiple of the width of the structure. Very particularly preferred is the design of a working zone that corresponds substantially exactly to the simplicity of a width of the structure. This means that, for example, in the provision of meshing profile rollers, the working zone of a tooth of the profile roller, which ultimately determines the width of the structure, is created as the second tool

Finally, there is proposed the use of a structured sheet produced by a method as described above, this structured sheet for producing an exhaust gas treatment apparatus for mobile internal combustion engines. Basically, it should be noted that with sheet here meant a cut to a certain length range of the sheet metal strip. When In particular, catalyst carrier bodies, adsorbers, particle filters, flow influencers, etc. are suitable for the exhaust gas treatment apparatus. With regard to internal combustion engines, diesel or gasoline engines of automobiles are particularly meant.

Fig. 1

schematisch den Aufbau einer Vorrichtung zur Herstellung eines strukturierten Blechs gemäß der Erfindung;

Fig. 2

eine Darstellung zur Veranschaulichung einer Ausführungsform des erfindungsgemäßen Verfahrens;

Fig. 3

schematisch und perspektivisch eine Detailansicht eines Blechbandes mit einer Struktur;

Fig. 4.1, 4.2, 4.3

jeweils eine Detailansicht einer Ausgestaltung des in Fig. 3 gekennzeichneten Figurenausschnittes;

Fig. 5

ein Ausführungsbeispiel des Blechbandes nach einer ersten Blechbearbeitung mit dem ersten Werkzeug;

Fig. 6

ein Ausführungsbeispiel eines Bleches nach der Herstellung mit der erfindungsgemäßen Vorrichtung bzw. Verfahren.

The invention and the technical environment are explained below, with reference to the figures. The figures show particularly preferred embodiments of the inventions, but the invention is not limited to these. Show it:

Fig. 1

schematically the structure of an apparatus for producing a structured sheet according to the invention;

Fig. 2

a representation for illustrating an embodiment of the method according to the invention;

Fig. 3

schematically and in perspective a detailed view of a sheet metal strip with a structure;

Fig. 4.1, 4.2, 4.3

in each case a detailed view of an embodiment of the in Fig. 3 marked figure detail;

Fig. 5

an embodiment of the sheet metal strip after a first sheet metal processing with the first tool;

Fig. 6

an embodiment of a sheet after production with the device or method according to the invention.

Fig. 1 shows schematically and simplifies the structure of a device for producing a structure 1 in a smooth sheet-metal strip 2. The smooth sheet-metal strip 2 is supplied from a supply 20, which is shown here as a coil, the device. The device, which is mounted here in a common housing 22, comprises a first tool 4 for sheet metal processing and a second tool 6 for sheet metal processing. The first tool 4 and the second tool 6 are arranged directly one behind the other. At the same time (with the forming of a second section 5 of the sheet-metal strip 2 with the second tool 6), a first section 3 the first tool 4 and a new second section 5 the second tool 6 supplied. The second tool 6, which is formed here with meshing profile rollers 14, has a rotary drive 16, which thus implements the sole feed of the sheet-metal strip 2 in the device. The first tool 4 is designed as a punching device and has a lifting drive 14. The first tool 4 and the second tool 6 have a very small distance 13 to each other.

The sheet-metal strip is clamped by means of the second tool 6 and one, the first tool 4 prefixed, holding device 11, which is designed here as a brake or frictional resistance. Between the holding device 11 and the first tool 4, a roller 21 is also provided, with which a fuel 12 is applied to the surface of the sheet-metal strip 2.

Fig. 2 represents the movements of the tools during a work cycle. In the row shown above, the movement of the first tool 4 comprising a (punching) knife 23 and a camshaft 24 is shown. Below this, the movement of the second tool 6 is shown greatly simplified, wherein the movement of the meshing profile rollers 15 is characterized. Below these sketches there is a diagram of the path (s) covered by the respective tool over time (t). The two graphs shown are labeled "A" for the movement of the first Tool 4 and "B" for the movements of the second tool 6.

At the time (I), the step c) of the method according to the invention, in which sheet metal working of the first section of the sheet metal strip with the first tool 4 is started, is just beginning. The camshaft 24 sets the knife 23 of the figure downwards in motion, so that the knife 23 penetrates into the sheet metal strip. At the time (II), the knife 23 has reached its lowest point, the metal strip 2 thus completely penetrated. This is followed by an upward movement of the blade 23, until it has its original position, as already at the time (I), taken at the time (III). During the entire punching process from time (I) to (III), the position of the profile wheels 15 has not changed to each other. Only now, at the time (III) to move the profile wheels 15 to each other and form a new structure and move the sheet metal strip in the feed direction. Although the camshaft continues to rotate at this time, the blade 23 does not perform a working stroke. When the camshaft 24 is again in the position that the knife 23 starts to move immediately (see time (IV)), the profiled rollers 15 have stopped again, which is equivalent to step b) of the method according to the invention. Now, this process for producing a structure in a metal strip repeats itself again. In this case, a repetition rate of at least 5 hertz is realized, where between (I) and (I '), ie a fifth of a second has passed.

Fig. 3 shows schematically and in perspective a part of a metal strip 2 with a primary structure 9 and a secondary structure 10. The sheet metal strip 2 comprises in the partial section shown a secondary structure 10, which is partially bounded by two holes 8, which are designed here as slots, wherein these Slits extend only in an inner region of the sheet-metal strip 2. The secondary structure 10 projects out of the primary structure 9 of the sheet-metal strip 1. The primary structure 9 is designed with wave crests 25 and troughs 26. The Edge regions 27 of the slots are, as indicated, enlarged in the following Fig. 4.1, 4.2 and 4.3 shown. The sheet-metal strip 2 is shown in a section which substantially corresponds to the working zone 17 of the first tool and the second tool.

Fig. 4.1, 4.2 and 4.3 show detailed views of a secondary structure 10, which is bounded by a hole 8. The hole 8 allows the secondary structure 10 to be formed from the sheet metal strip 2 so that it emerges from the primary structure 9. In Fig. 4.1 is the edge region 27 shown as a simple slot. In the Fig. 4.2 and 4.3 are provided in the edge region 27 of the hole 8 recesses 31. The recesses 31 in Fig. 4.2 forms a circular arc 30 with a radius of curvature 32, which is preferably in the range of 0.2 mm to 0.4 mm. In Fig. 4.3 the recess 31 is shown as an undercut. Other, for example, the notch effect reducing, forms of the recesses 31 can also be used.

Fig. 5 schematically shows a metal strip 2, as it may be designed after processing by the first tool. The sheet-metal strip 2 has a plurality of holes 8, which are arranged in rows 35 and in lines 34 to each other. The openings 8 are made in the edge regions 27 with recesses 31, wherein the two recesses 31 are connected to each other via a slot 28. All holes 8 are arranged in an inner region 33 of the sheet-metal strip 2. The holes 8 must now be aligned exactly to the second tool, since they at least partially define a secondary structure 10.

Fig. 6 shows a finished sheet 19 with a structure 1, which was produced by the method according to the invention or the device according to the invention. The sheet 19 thus has a structure 1 (or primary structure), which is superimposed by a secondary structure 10. The secondary structure 10 is formed here with guide surfaces 29, which limit the respective hole 8 in part. The guide surfaces 29 are in both the Wellentälern 26 and arranged in the wave crests 25 and are each oriented opposite. The structure 1 can be described by a height 36 and a width 18, where by height 36 is meant the distance from wave peak 25 to wave valley 26 and with width 18 the distance between two neighboring wave peaks 25 and wave troughs 26. The ratio of width 18 to height 36 is preferably in a range of 2.0 to 1.3. In this way, channel densities of exhaust treatment devices can be formed ranging from 100 to 1000 cpsi ("cells per square inch", 6.45 channels / square inch equivalent to one channel / cm ² ).

The method described here or the device proposed here allow a particularly precise guidance of the sheet metal strip during the production of very complex structures. At the same time, a particularly space-saving arrangement of the tools can accomplish and realize a high processing speed.

LIST OF REFERENCE NUMBERS

1

structure

2

metal strip

3

first section

4

First tool

5

second part

6

Second tool

7

feed direction

8th

hole

9

primary structure

10

secondary structure

11

holder

12

fuel

13

distance

14

Hub Drive

15

corrugated roll

16

Rotation drive

17

work zone

18

width

19

sheet

20

stock

21

role

22

casing

23

knife

24

camshaft

25

Wellenberg

26

trough

27

border area

28

slot

29

baffle

30

arc

31

expansion

32

radius of curvature

33

interior

34

line

35

line

36

height

Claims (12)

1. A process for producing a structure (1) in a smooth sheet-metal strip (2), comprising at least the following steps:

   a) feeding a first section (3) of a smooth sheet-metal strip (2) to a first tool (4) and feeding a second section (5) of the sheet-metal strip (2) to a second tool (6) in a feed direction (7);

   b) stopping the sheet-metal strip (2);

   c) performing a sheet-metal machining of the first section (3) of the sheet-metal strip (2) with a first tool (4) in which at least one hole (8) is produced in the first section (3);

   d) performing a sheet-metal machining of the second section (5) of the sheet-metal strip (2) with a second tool (6) simultaneously with step a), wherein a structure (1) is produced in the second section (5) of the sheet-metal strip (2) wherein the second section (5) has already at least one hole (8) and the second tool (6) engages in the at least one hole (8);

   and the sheet-metal strip (2) is tensioned by means of the second tool (6) and a holding apparatus (11) mounted in front of the first tool (4).
2. The process as claimed in claim 1, in which step d) produces a structure (1) in the second section (5) of the sheet-metal strip (2) which has a primary structure (9) and a secondary structure (10).
3. The process as claimed in one of the preceding claims, in which step c) comprises stamping a plurality of holes (8).
4. The process as claimed in one of the preceding claims, in which step d) comprises the corrugation rolling of the sheet-metal strip (2).
5. The process as claimed in one of the preceding claims, in which steps a) to d) are carried out repeatedly, the repetition rate amounting to at least 5 hertz [¹/second].
6. The process as claimed in one of the preceding claims, in which the sheet-metal strip (2) is brought into contact with an operating substance (12) at least before step c).
7. An apparatus for producing a structure (1) in a smooth sheet-metal strip (2), comprising at least a first tool (4) for sheet-metal machining and a second tool (6) for sheet-metal machining, characterized in that the first tool (4) and the second tool (6) are arranged in direct succession with a distance (13) of less than 1000 millimeters [mm] to each other and the second tool (6) has means for simultaneously carrying out sheet-metal forming and sheet-metal strip feeding and further the first tool (4) serves for the production of at least one hole (8), in that the second tool (6) engages, wherein the sheet-metal strip (2) is tensioned by means of the second tool (6) and a holding apparatus (11) being mounted in front of the first tool (4).
8. The apparatus as claimed in claim 7, characterized in that the first tool (4) is a stamping tool.
9. The apparatus as claimed in claim 8, characterized in that the stamping tool has a lifting drive (14) which produces a working cycle and an idling cycle.
10. The apparatus as claimed in one of claims 7 to 9, characterized in that the second tool (6) comprises profiled rolls (15) which mesh with one another.
11. The apparatus as claimed in claim 10, characterized in that the second tool (6) has a rotary drive (16) which provides a rotation cycle frequency of at least 5 hertz [¹/second].
12. The apparatus as claimed in one of claims 7 to 11, characterized in that at least the first tool (4) or the second tool (6) has a working zone (17) which corresponds to a multiple of a width (18) of the structure (1).

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