DE4338327A1 - Catalytic converter and method for the production of the same for a motor vehicle - Google Patents

Abstract

In a method for the production of a catalytic converter, first of all a backing film and a separating film are each coated on both sides with a catalyst material, for example platinum, and then preferably wound together on a spike (18) to form a winding body (20). The spike (18) preferably has at both ends radially outwardly protruding supporting elements (22) which enclose both ends of the winding body (20) thus securing it against axial displacement. In addition, a layer (24) of insulating material can be applied to the winding body (20), which layer preferably protrudes at least partially outwards over the radial supporting elements (22) and the thus formed catalyst body (16) is then inserted into an exhaust pipe and fixed thereto by, for example, the exhaust pipe being cold-formed at both ends of the catalyst body (16) to form a tapered portion, with the result that the catalyst body (16) is retained in a form fitting manner in the exhaust pipe (Fig. 2). <IMAGE>

Description

The invention relates to an exhaust gas catalytic converter for a motor vehicle stuff with a catalyst body held in an exhaust pipe is, wherein the catalyst body is a winding body from a Large number of layers with several adjacent layers has, wherein a layer of a corrugated carrier film  is provided and wherein at least a second layer of a Separating film is provided, the adjacent layers of the carrier film separates from each other in the winding body.

The invention further relates to a method of manufacture an exhaust gas catalytic converter for a motor vehicle, in which a first layer of a corrugated carrier film on a second Layer of a release film is placed and the two from the carrier film and the separating film layers formed Production of a multi-layer package, and the winding body thus produced after coating device with a layer of a catalyst material in one Exhaust pipe is introduced and against axial displacement in the Exhaust pipe is secured.

According to a conventional method of manufacturing a Exhaust gas catalytic converter for a motor vehicle is first a composite formed from three layers in which a corrugated carrier film on a solder foil and this in turn on a smooth release foil is placed. This three-layer composite now becomes one circular cylindrical or oval in cross-section wound up. Here, the release film is provided to prevent waves and bellies from adjacent layers of the beams slide into each other, the gas through the catalyst body form gears.

The finished bobbin is then subjected to heat soldered by placing the inserted solder foil along the The bellies of the foil have a solder seam between the carrier foil and Release film results. This self-supporting wrap after soldering The body is then steamed with platinum and placed in an exhaust pipe soldered.  

In this known method, it has proven to be problematic proved the winding body after their manufacture with platinum to vaporize. Since the self-supporting winding body is not one have insignificant length, which is quite the size order of 20 or 30 cm is one possible complete vaporization in the narrow gas passages between Carrier film and release film difficult to reach and demented speaking complex and expensive.

Furthermore, the winding is formed from three layers Composite and the subsequent soldering quite cumbersome. Furthermore, the is additionally introduced into the winding body Solder foil unnecessarily increases the total weight of the catalyst and when soldering, the fine gas passages can partially ver be closed.

The invention is therefore based on the object of an exhaust gas catalyst and a method for producing an exhaust gas to create a catalyst, with the disadvantages of the prior art Technology can be avoided and a high effectiveness of the catalytic converter tors is achieved with the simplest possible manufacture.

With regard to the method, this object is achieved according to the invention solved in that first a first layer of a corrugated carrier film on a second layer of a release film is placed that then from at least two layers formed composite is wound around a multi-layer winding produce body that the winding body against popping ge is secured and in at least one end with support elements in an exhaust pipe is inserted and secured against axial displacement becomes.  

The necessary coating with catalyst material can be used either by coating the corrugated carrier film the winding or by a later coating of the Coils passing through in the axial direction, for example through Steaming.

Unless the coating with catalyst material, as a rule Platinum, already before the winding body was manufactured, it is made possible that the catalyst material in simpler Be applied flat to the corrugated carrier film can. A complicated coating of thin gas passages after the manufacture of a winding body is avoided.

According to the invention, the use of a solder foil is dispensed with and the winding body is against the relatively large in operation Axial forces ge by support elements at at least one end backs up.

According to the invention, a safeguard against axial displacement the individual layers or wraps were supported by support elements achieved, which are preferably arranged radially. Since the The soldering process is omitted and thus the individual layers and layers of the winding former not subsequently with a layer of one Solder material can be coated, the coating before Wind up if desired.

After the manufacture of the winding body is expedient the top layer on the winding body, for example by soldering or spot welding fixed before the bobbin in one Exhaust pipe is inserted and against axial displacement within the exhaust pipe is secured.  

In a preferred development of the invention, the two layers formed from the carrier film on a mandrel which protruding radially outwards at at least one end Support elements is provided, wound up.

On the one hand, this makes the manufacture of the winding body relieved, on the other hand, is already in the manufacture of the A simple and reliable securing of the same reached against axial displacement.

In an advantageous development, both the Carrier film as well as the release film before the production of the Winding body with a layer of the catalyst material Mistake.

This measure has the advantage that a the highest possible surface area of the catalyst with the catalyst material is coated so that the available active catalyst area is maximized and thus a possible high efficiency of the catalyst is achieved.

According to a further feature of the invention, the coating the carrier film and optionally the release film galvanically carried out.

This measure has the advantage of being a controlled layer thickness of the catalyst material on particularly simple and inexpensive way on the carrier film and the release film can be applied.

In a further preferred embodiment of the invention, the mandrel, which carries the winding body, at both ends with radial Provide support elements.  

Although it would be sufficient in principle, radial support elements at the rear end of the exhaust gas seen in the direction of flow Provide winding body, since axial forces essentially will only occur in the direction of flow of the exhaust gases in this way a safe inclusion of the winding body achieved its two ends between the radial support elements, so that after fixing the outermost layer on the winding body a self-supporting winding body is created at both ends is enclosed between the radial support elements.

The radial support elements can in a further embodiment of the method according to the invention welded to the mandrel or to be soldered.

In this way, an easy to manufacture and permanent connection of the radial support elements to the mandrel to reach.

In a further advantageous embodiment of the invention the first layer is made from the two from the selected carrier film and the separating film layers formed on a slot of the Fixed thorn.

This can be done in an advantageous manner, for example, in that the first layer through a radial through the mandrel inserting slot is inserted in a similar manner, like the end of a film on a film reel in Radialrich device penetrating slot is fixed.

This is a quick and easy way to attach the ensured the first position of the winding body on the mandrel.  

In an additional development of the method according to the invention is provided, the exhaust pipe after inserting the winding body to deform pers at both ends of the winding body in such a way that at both ends of the winding body tapered sections of the Exhaust pipe arise between which the winding body closed and thus secured against displacement in the axial direction is. The deformation can expediently by Cold forming can be achieved.

This measure has the advantage that a weld or Soldering the winding body or the radial support elements can be dispensed with with the exhaust pipe and that a permanent and reliable securing of the winding body through the form conclusive backup is achieved.

In an advantageous development of the invention, that on the winding body a layer of an insulating material is applied before the winding body into the exhaust pipe is introduced.

While in a conventional way the catalyst is based on a the exhaust pipe insulated from the outside insulating layer is, the insulating material can advantageously in introduced the exhaust pipe surrounding the catalyst body and so on the one hand good thermal insulation of the catalytic converter gate body reached against the exhaust pipe surrounding it and at the same time without additional measures protection of the insulating material against mechanical damage can be reached from the outside.  

In an additional development of this method, that the insulating layer is applied to the winding body in this way is that this is at both ends between the radial support elements is at least partially held.

In this case, the insulating layer is preferably in the radial direction compared to the radial support elements, so that a direct contact of the radial support elements on the Exhaust pipe and thus a thermal bridge between the radial Support elements and the exhaust pipe is avoided.

In an additional development of the invention Winding body from the outside a plurality of circumferentially running beads introduced before a layer of insulation material is applied to the winding body.

Through these beads running in the axial direction, a Securing the insulating material against displacement in the axial direction tion achieved without the insulating material at least partially must be kept between the radial support elements.

Thus, the winding body itself can have a larger diameter or have a greater strength, since a larger overall Number of layers can be applied to the mandrel since the Number of layers due to the radial expansion of the support elements is limited. Thus, with the same volume of catalyst somewhat larger active catalyst area provided become, which leads to a better effectiveness of the catalyst.

The insulating material can from the outside with around the radial support elements are wrapped around, which additionally increases the heat Isolation of the catalyst is improved.  

With regard to the catalytic converter, the task is performed by a Solved catalyst body, which is held in an exhaust pipe, wherein the catalyst body is a winding body from a plurality of layers with several adjacent layers has, wherein a first layer of a corrugated carrier film and at least a second layer of a release film is provided, the adjacent layers of the carrier film in Separates winding body from each other, and at least the corrugated Carrier film is coated with a catalyst material, and wherein the winding body through at least one axial end Support elements is secured against axial displacement.

In an exhaust gas catalyst according to the invention, the Use a solder foil between the individual layers of the Dispensing body. Rather, it is the winding body Stability conferred that the individual layers at least on one axial end by supporting elements against axial displacement as a result the forces exerted by the exhaust gases are secured. Since the Coating the carrier film and the release film before the manufacture of the winding body can take place, such particularly even coating of the thin gas passages with a layer of catalyst material, preferably made of Platinum can be guaranteed, so that the catalyst as a result the uniform coating is particularly effective having. In addition, due to the uniform coating tion of the carrier film and the release film with catalyst material the total thickness of the coating can be reduced overall, which saves catalyst material, usually platinum becomes.

In an advantageous development of the invention, the supports elements arranged radially.  

This provides a reliable safeguard against axial displacement reached.

In a further advantageous embodiment, the winding body wound on a mandrel, preferably with the radial Support elements is connected.

This simplifies production and stability of the winding body enlarged.

In an expedient development of the invention, the winding body at both axial ends enclosed by radial support elements which are connected to the mandrel.

This measure has the advantage that the winding body on both Ends are equally secured against axial displacement, so that installation in the exhaust pipe regardless of the flow direction tion of the exhaust gases can take place.

The radial support elements are in a preferred development of the invention designed as wing-like elements that taper radially outwards from the mandrel and try one have a small cross-section.

This measure has the advantage that the flow resistance of the radial support elements is minimized, so that the dynamic pressure is reduced on the catalyst.

In an additional development of the invention, the mandrel of penetrated a longitudinal slot in the radial direction.  

The first layer of the winding body can thus be fastened to be inserted through the slot, resulting in a particularly easy fixation on the mandrel results.

According to a further feature of the invention, the winding body enclosed by an insulating layer, which is insulating and preferably also has sound-absorbing properties.

Compared to conventional designs in which the catalyst body through one from the outside onto the catalyst body closing exhaust pipe is applied, will be better Thermal insulation achieved while protecting the insulation layer against mechanical damage from the outside.

In a first embodiment, the insulating layer can be on their axial ends at least from the radial support elements be partially enclosed.

Thus, on the one hand, the insulating layer is secured against Axial displacement reached on the winding body and on the other hand a contact of the radial support elements with the catalyst body-surrounding exhaust pipe avoided, so that the heat isolation is improved.

In an alternative embodiment, the winding body has beads running in the circumferential direction to secure the insulation layer against axial displacement.

Since the insulation layer is thus against axial displacement when inserted into the exhaust pipe is secured, the winding body itself can have a larger cross section overall have and the insulating layer, the radial support elements include completely from the outside.  

It is understood that the above and the following standing features to be explained not only in each specified combination but also in other combinations and can be used alone, without the scope of the Leaving invention.

Further features and advantages of the invention result from the following description of a preferred embodiment example with reference to the drawing. In it show:

Figure 1 shows an exhaust gas catalyst according to the invention in Längsan;

Fig. 2 is a front view of a catalyst body according to the invention with external insulation before installation in the exhaust pipe according to Figure 1 in an enlarged view.

Figure 3 shows a mandrel according to the invention for receiving the winding body and with radial support elements at both ends.

Fig. 4, the mandrel of FIG. 3 after applying the Wickelkör pers and introducing beads in the circumferential direction of the winding body and

Fig. 5 shows a detail of the bobbin shown in FIG. 2 in an enlarged view, wherein only two adjacent layers are shown in schematic representation.

An exhaust gas catalytic converter according to the invention is shown schematically in FIG. 1 and is designated overall by the number 10 .

The catalytic converter 10 is received by an expanded section 13 of an exhaust pipe 12 , which has a circular cross section. At both axial ends of the catalytic converter body, which will be described in more detail in the following figures, the exhaust pipe 12 has tapered sections 14 , through which the catalytic converter body is positively secured in the axial direction within the exhaust pipe 12 .

It goes without saying that the exhaust pipe and in particular the expanded section 13 for receiving the catalyst body can also have a different cross-sectional shape, in particular an oval cross-sectional shape.

The catalyst body accommodated within the enlarged section 13 is designated overall by the number 16 in FIG. 2.

The catalyst body 16 has a winding body 20 which is wound onto a central mandrel 18 and, as can be seen from FIGS. 3 and 4, is enclosed by radial support elements 22 at both axial ends. At each end of the mandrel 18 , four radial support elements 22 are arranged at regular angular intervals of approximately 90 ° and permanently attached to the mandrel 18 by welds 26 according to FIG. 3, which is designed as a thin tube. The tube is closed at at least one end to avoid gas passage through the tube.

As can be seen from FIGS . 2 and 3, the radial support elements 22 have a very small cross section when viewed in the axial direction of the catalytic converter and taper radially outward from the mandrel 18 like wing-like elements. In this way, the radial support elements 22 result in a very low flow resistance for the exhaust gases flowing through the catalyst body 16 in the axial direction.

The winding body 20 consists of a plurality of layers which are wound onto the mandrel 18 . Each layer consists of two adjacent layers, each of which is formed by a film, as is shown schematically in FIG. 5.

Fig. 5 shows two adjacent layers 32 and 34, each comprising a first layer of a corrugated support film 36 and a second layer of a substantially smooth release film 40 to have.

Both the corrugated carrier film 36 and the release film 40 are coated on both sides with a layer of a catalyst material 38 , 39 , which is platinum in the present case. Before the winding body 20 is produced, the coating is applied galvanically to the corrugated carrier film 36 and to the separating film 40 and has a very uniform but low thickness on both sides of the respective films.

As can be seen from FIG. 5, each layer has an adjacent layer of carrier film 36 and separating film 40 , so that in adjacent layers 32 , 34 of carrier film 36 are separated from one another by a layer of separating film 40 . In this way it is achieved that adjacent layers 32 , 34 of the carrier film 36 cannot slide into one another, so that a reduction in the active area of the catalyst is avoided.

As seen from Fig. 3, the mandrel 18 in longitudinal direction is penetrated radially within the free space between the end radial support members 22 of a longitudinal slot 28.

When winding the winding body 20 , a first layer 32 , which consists of carrier film 36 and adjacent release film 40, is inserted through the longitudinal slot 28 of the mandrel 18 and then wound on the mandrel 18 until a multi-layer winding body 20 according to FIGS. 2 and 4 is formed . When the first layer 32 is inserted through the longitudinal slot 28 , the first layer is secured in the manner known for winding films onto film spools which have a longitudinal slot.

The uppermost layer of the winding body 20 is fixed to the underlying layer after the winding process has ended, for example soldered to it.

A plurality of beads 30 which run in the circumferential direction of the winding body 20 are then pressed onto the winding body 20 .

Finally, a layer 24 made of an insulating material is applied to the winding body ( FIG. 2), which may consist of mineral wool, for example, and has both heat-insulating and sound-insulating properties. The thickness of this insulating layer 24 is such that it protrudes slightly beyond the radial support elements 22 .

In this way, the insulating layer 24 is enclosed on the one hand between the radial support elements 22 at both ends and, on the other hand, protrudes outwards in such a way that when the catalyst body 16 is subsequently introduced into the exhaust pipe 12, contact of the radial support elements 22 with the exhaust pipe 12 is avoided. which results in improved heat and sound insulation.

Through the beads 30 on the circumference of the winding body 20 , an additional securing of the insulating layer 24 against displacement in the axial direction is achieved.

In an alternative embodiment, the winding body 20 can therefore also have a somewhat larger diameter than the embodiment shown in FIG. 4, that is to say it can be provided with further layers, such that the outermost layer of the winding body 20 is still securely between the radial support elements 22 at both ends is included.

The insulating layer 24 can then be applied by wrapping it with an appropriate insulating material, the radial supporting elements 22 being able to be wrapped around from the outside, since the insulating layer 24 is adequately secured against axial displacement by the beads 30 when the catalytic converter body 16 is inserted into the exhaust pipe 12 .

The catalyst body 16 is in the examples shown here Ausfüh approximately in any case provided with an outer insulating layer 24 , which is secured either by the peripheral beads 30 additionally or exclusively by the radial support elements 22 against axial displacement.

After inserting the catalyst body 16 into the exhaust pipe 12 , this is tapered at both ends of the catalyst body 16 by cold working, so that the catalyst body 16 is located within the enlarged section 13 of the exhaust pipe 12 , which has the outer diameter D₂ and at both ends between tapered sections 14 of the exhaust pipe 12 , which have the outer diameter D₁, is included, so that a positive locking of the catalyst body 16 against axial displacement is achieved.

The diameter D 1 is only reduced by a few percent compared to the diameter D 2, since even a slight taper is sufficient to achieve the necessary securing of the catalyst body 16 against axial displacement as a result of the flowing exhaust gases in a reliable and permanent manner.

In principle, it would also be possible to provide a multi-layer winding body, which is formed from three layers as is conventional with an additional solder foil for soldering the winding body, with beads 30 according to FIG. 4 and together with the applied insulating layer 24 into the exhaust pipe 12 to be inserted and then positively secured by cold forming at both ends.

However, it is preferred according to the invention to manufacture the winding body 20 as described above only from two layers with a carrier film and an adjacent separating film, with the winding body 20 itself being secured against axial displacement by the radial support elements 22 . This version can be manufactured much more easily than the previously mentioned alternative and, owing to the improved, more uniform coating of the films before the manufacture of the winding former, has an improved efficiency and also leads to savings in catalyst material.

Claims (23)

1. A method for producing an exhaust gas catalytic converter for a motor vehicle, which comprises at least the following steps:

• Coating a corrugated carrier film ( 36 ) with a layer of a catalyst material,
• - placing a first layer of the corrugated carrier film ( 36 ) on a second layer of a carrier film ( 40 ),
• - winding up the two layers formed from the carrier film ( 36 ) and the separating film ( 40 ) until a multi-layer winding body ( 20 ) is formed,
• Securing the outermost position of the winding body ( 20 ) against popping open,
• Attaching support elements ( 22 ) to at least one end of the winding body ( 20 ),
• - Introducing the winding body ( 20 ) into an exhaust pipe ( 12 )
• - Secure the winding body ( 20 ) against axial displacement in the exhaust pipe ( 12 ).

2. A method for producing an exhaust gas catalytic converter for a motor vehicle, which comprises at least the following steps:

• - placing a first layer of a corrugated carrier film ( 36 ) on a second layer of a separating film ( 40 ),
• - winding up the two layers formed from the carrier film ( 36 ) and the separating film ( 40 ) until a multi-layer winding body ( 20 ) is formed,
• Securing the outermost position of the winding body ( 20 ) against popping open,
• Applying a layer of a catalyst material to the channels passing through the winding body ( 20 ) in the axial direction,
• Attaching support elements ( 22 ) to at least one end of the winding body ( 20 ),
• - Introducing the winding body ( 20 ) into an exhaust pipe ( 12 ),
• - Secure the winding body ( 20 ) against axial displacement in the exhaust pipe ( 12 ).

3. The method of claim 2, wherein the coating is carried out galvanically.   4. The method according to one or more of the preceding claims, wherein the two layers formed from the carrier film ( 36 ) and the separating film ( 40 ) on a mandrel ( 18 ) which has at least one end with radially outwardly projecting support elements ( 22 ) is provided, be wound up. 5. The method according to claim 4, wherein the mandrel ( 18 ) is provided at both ends with radial support elements ( 22 ). 6. The method according to claim 4 or 5, wherein the radial support elements ( 22 ) with the mandrel ( 18 ) are welded or soldered. 7. The method according to one or more of claims 4, 5 or 6, in which the first layer ( 32 ) of the two layers formed from the corrugated carrier film ( 36 ) and the separating film ( 40 ) on a longitudinal slot ( 28 ) of the mandrel ( 18 ) is fixed. 8. The method according to claim 7, wherein the first layer ( 32 ) is inserted through the longitudinal slot ( 28 ) which penetrates the mandrel ( 18 ) in the radial direction. 9. The method according to one or more of the preceding claims, wherein the exhaust pipe ( 12 ) is deformed at both ends of the winding body ( 20 ) such that tapered sections ( 14 ) of the exhaust pipe ( 20 ) are formed at both ends of the winding body ( 20 ) , between which the winding body ( 20 ) is fixed in the axial direction. 10. The method according to one or more of the preceding claims, a layer (24) is applied from an insulating material in which the winding body (20) before the winding body (20) is introduced into the exhaust pipe (12). 11. The method according to claim 10, wherein the layer ( 24 ) of the insulating material is at least partially held at both ends between the radial support elements ( 22 ). 12. The method according to one or more of the preceding claims, a plurality introduced from extending in the circumferential direction of corrugations (30) in which the winding body (20) before a layer (24) is applied of insulating material onto the winding body (20). 13. Catalytic converter for exhaust gas purification for a motor vehicle, with a catalytic converter body ( 16 ) which is held in an exhaust pipe ( 12 ), the catalytic converter body ( 16 ) being a winding body ( 20 ) composed of a plurality of layers ( 32 , 34 ) with a plurality of one another has adjacent layers, a first layer of a corrugated carrier film ( 36 ) and at least a second layer of a separating film ( 40 ) which separates adjacent layers ( 32 , 34 ) of the carrier film ( 36 ) in the winding body ( 20 ), wherein at least the corrugated carrier film ( 36 ) is coated with a layer ( 38 ) of a catalyst material, and wherein the winding body ( 20 ) is secured against axial displacement at least at one axial end by supporting elements. 14. The catalytic converter according to claim 13, wherein the support elements ( 22 ) are arranged radially. 15. Exhaust gas catalyst according to claim 13 or 14, wherein the winding body ( 20 ) is wound on a mandrel ( 18 ). 16. The catalytic converter according to claim 15, wherein the radial support elements ( 22 ) are connected to the mandrel ( 18 ). 17. The catalytic converter according to one or more of claims 14 to 16, wherein the winding body ( 20 ) is enclosed at both axial ends by radial support elements ( 22 ) which are connected to the mandrel ( 18 ). 18. Exhaust gas catalytic converter according to one or more of claims 14 to 17, in which the radial support elements ( 22 ) are designed as wing-like elements which taper radially outward from the mandrel ( 18 ) and have the smallest possible cross section. 19. The catalytic converter according to one or more of claims 15 to 18, wherein the mandrel ( 18 ) has a longitudinal slot ( 28 ) for fastening a first layer ( 32 ) of the winding body ( 20 ). 20. The catalytic converter according to one or more of claims 13 to 19, wherein the winding body ( 20 ) is enclosed by a layer ( 24 ) made of an insulating material. 21. The catalytic converter according to claim 20, wherein the layer ( 24 ) of insulating material is at least partially enclosed at its axial ends by the radial support elements ( 22 ). 22. An exhaust gas catalytic converter according to claim 20 or 21, wherein the winding body ( 20 ) has beads ( 30 ) extending in the circumferential direction to secure the layer ( 24 ) of insulating material against axial displacement. 23. Exhaust gas catalytic converter according to one or more of claims 13 to 22, wherein the exhaust pipe ( 12 ) for receiving the catalyst body ( 16 ) has an enlarged section ( 13 ) which at both ends of the catalyst body ( 16 ) in each case in a tapered section ( 14 ) passes.