CATALYTIC CONVERTER AND METHOD FOR THE PRODUCTION THEREOF

Abstract

A catalytic converter for exhaust gas aftertreatment, with a matrix and a casing, the matrix is formed from a coiled layered stack of metal sheets and is inserted into the casing and bonded thereto only in portions and a method for producing a catalytic converter.

Claims

1.-14. (canceled)

15. A catalytic converter for exhaust gas aftertreatment, comprising: a casing; and a matrix formed from a coiled layered stack of metal sheets, wherein the matrix is inserted into the casing and bonded to the casing only in portions.

16. The catalytic converter as claimed in claim 15, wherein the casing has protrusions directed radially inwardly in at least one of an axial direction and a circumferential direction, wherein radially inwardly pointing faces of the protrusions form contact points between the matrix and the casing.

17. The catalytic converter as claimed in claim 16, wherein the protrusions have an equivalent diameter of 2 mm to 20 mm.

18. The catalytic converter as claimed in claim 16, wherein the protrusions have a spacing of 0 mm to 25 mm in the one of the axial direction and the circumferential direction.

19. The catalytic converter as claimed in claim 16, wherein the protrusions have a depth of 0.1 mm to 5 mm in a radial direction of the casing.

20. The catalytic converter as claimed in claim 15, wherein the casing has beads which are spaced apart from each other in an axial direction and run at least partially round in an circumferential direction.

21. The catalytic converter as claimed in claim 20, wherein radially inwardly pointing faces of the beads form contact points to the matrix.

22. The catalytic converter as claimed in claim 15, wherein on a radially inwardly pointing face of the casing, the casing has solder points arranged at regular or irregular distances from each other in an axial direction and in a circumferential direction.

23. The catalytic converter as claimed in claim 22, wherein a surface area of a respective solder point is between 10 mm.sup.2 and 700 mm.sup.2.

24. The catalytic converter as claimed in claim 23, wherein the solder points are circular and have a diameter of at least one of between 5 mm and 30 mm and between 7 mm and 20 mm.

25. The catalytic converter as claimed in claim 22, wherein a distance between two solder points in an axial direction of the casing is at least one of between 5 mm and 40 mm and between 20 mm and 30 mm.

26. The catalytic converter as claimed in claim 22, wherein a distance between two solder points in a circumferential direction is at least one of between 5 mm and 30 mm and between 15 mm and 20 mm.

27. The catalytic converter as claimed in claim 15, wherein the matrix is formed exclusively from corrugated layers.

28. A method for production of a catalytic converter, comprising: (a) producing a matrix by stacking at least two metallic layers onto each other and coiling the at least two metallic layers; (b) applying solder to a radially inwardly pointing face of a casing; (c) inserting the matrix into the casing; (d) soldering the matrix to the casing using the applied solder; and applying an adhesive to the casing using a gluing roller, wherein the gluing roller has elevations on its radially outwardly pointing face via which the gluing roller rolls on the radially inwardly pointing face of the casing, wherein the adhesive is applied to the casing according to an arrangement of the elevations.

29. The method for production of the catalytic converter as claimed in claim 28, wherein steps (a) to (d) are performed successively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention will be explained in detail in the following text on the basis of exemplary embodiments with reference to the drawings, in which:

[0029] FIG. 1A is a perspective partial view of a matrix in a casing;

[0030] FIG. 1B is a perspective partial view of a matrix in a casing;

[0031] FIG. 2 is a diagrammatic view of a casing with beads running in the circumferential direction;

[0032] FIGS. 3A and 3B are cross-sections through casings with beads running in the circumferential direction;

[0033] FIG. 4 is a partial view of a casing which has a pattern of solder points on its inner face;

[0034] FIG. 5A is a glueing roller for producing a solder point pattern on the inside of the casing FIG. 5B is a casing with a solder point pattern produced by the glueing roller;

[0035] FIGS. 6A and 6B are sectional views through two casings with beads running round in the circumferential direction, wherein the indicated matrix is formed from only two corrugated layers;

[0036] FIG. 7 is a sectional view through a catalytic converter with a diamond-patterned structure which is embossed into the casing;

[0037] FIG. 8 is a sectional view through a catalytic converter with a diamond-patterned structure which is embossed into the casing; and

[0038] FIG. 9 is a sectional view with a honeycomb-patterned structure which is embossed into the casing.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0039] FIG. 1A shows a casing 1 in which a matrix 2 is inserted. The casing 1 has a plurality of depressions 3 that form indentations in the casing 1. These indentations 3 may for example be embossed into the casing 1. The matrix 2 is formed by coiling a layered stack formed from alternating smooth and corrugated layers. Alternatively, the matrix may also be formed exclusively from corrugated layers stacked on top of each other with an angle offset to each other. Preferably, the offset angle is between 3 and 10.

[0040] Because of the indentations 3 formed as slots in FIG. 1A, a contact between the outer layers of the matrix and the casing is only formed in regions. Accordingly, on soldering, a bonded connection is created only in these contact regions. As an alternative to the slot-like design shown, the indentations may for example also be configured with circular form or with any other geometric design.

[0041] In FIG. 1B, a casing 4 is indicated that has slot-like depressions 5. Here too, a contact between the matrix 6 and the casing 4 exists only at the depressions, so that a bonded connection is also only created in these contact regions.

[0042] FIG. 2 shows a part portion of a casing 7 comprising beads 8 that run at least partially round in the circumferential direction and are spaced apart from each other in the axial direction. The beads 8, or the radially inwardly pointing deepest points 9 of the beads 8, form the contact regions of the matrix.

[0043] FIGS. 3A and 3B show two cross-sections through different casings 10, 11, wherein the casings 10, 11 each have several beads 12, 13 running round in the circumferential direction and spaced apart from each other in the axial direction. Here again, in each case the radially inwardly pointing faces of the beads 12, 13 form the contact regions which are used for connection to the respective matrix.

[0044] FIG. 4 shows a partial view of a casing 14, wherein several solder points 16 are applied in a solder point pattern on the radially inwardly pointing face 15. The solder points here are produced by spot application of an adhesive to the casing and subsequent loading with solder.

[0045] A connection can be created between the casing 14 and the matrix during the soldering process only at the points which are loaded with the solder.

[0046] FIG. 5A shows a glueing roller 17, which has several elevations 18 distributed over its periphery. This glueing roller is preferably made of a material with a suction capacity, for example a foamed material, and serves for application of an adhesive to the inner face of a casing. The solder point pattern created in the casing can be determined by the shape and arrangement of the elevations 18. The adhesive is transferred to the casing in a fashion similar to a printing process. In a subsequent step, the solder is deposited only at the regions loaded with the adhesive, and later creates the bonded connection in the soldering process.

[0047] In FIG. 5B, a casing 19 is depicted in which a solder point pattern 20 is produced by the glueing roller 17 shown In FIG. 5A. The solder point pattern 20 is here produced by rolling of the glueing roller 17 on the inner face of the casing 19.

[0048] FIGS. 6A and 6B show sectional views through a casing 21 and 22. The casings 21, 22 each have beads 23, 24 running in the circumferential direction. In the examples of FIGS. 6A and 6B, the indicated matrix 25, 26 is in each case formed solely by corrugated layers, so that at most, the tips of the corrugations of the corrugated layers make contact over the entire extension of the casing 21, 22, whereby sufficiently great flexibility is achieved in the connection between the casing 21, 22 and the matrix. Because of the beads 23, 24, the corrugation tips of the corrugated layers bear on the casing 21, 22 only in the region of the beads 23, 24, whereby the connecting points are further reduced and an even greater flexibility is achieved.

[0049] FIG. 7 shows a sectional view through a catalytic converter 30 according to one aspect of the invention, wherein around one quarter of the catalytic converter 30 is cut away to allow a view of the matrix 32 arranged in the casing 31.

[0050] The matrix 32 is formed from several metallic layers stacked on top of each other and coiled to form the finished matrix 32.

[0051] The casing 31 has a diamond-patterned structure, which was for example embossed therein from the outside. Because of the diamond-patterned embossing, protruding structures are created on the inner face of the casing 31 which project radially inwardly from the casing 31. These protruding structures serve as contact points between the casing 31 and the matrix 32. In the subsequent soldering process, a bonded connection between the casing 31 and the matrix 32 is only created at these contact points.

[0052] The right-hand part of FIG. 7 shows an enlargement of the portion of the catalytic converter 30 designated with reference sign A. In this enlargement, the contact points of the casing 31 bearing on the matrix 32 can be seen.

[0053] FIG. 8 shows a catalytic converter 33 with an alternative diamond-patterned embossing. The individual diamonds are larger and have a different orientation from those in FIG. 7. The contact points created by the embossed structure have a larger physical extension, so that the contact area between the casing 34 and the matrix 35 is greater than in the example of FIG. 7. The number of contact points between the casing 34 and the matrix 35 is thus smaller for the same size of catalytic converter.

[0054] The right-hand part of FIG. 8 shows an enlarged depiction of the portion marked with reference sign B, showing that the contact points are formed with a larger area and consequently bear on the matrix 35 over a larger area.

[0055] FIG. 9 shows a further catalytic converter 36 with a casing 37, which has an embossed honeycomb-like structure. The individual hexagons directly adjoin each other and thus also create structures protruding radially inwardly from the casing 37, which serve as contact points to the matrix 38.

[0056] As evident in FIGS. 7 to 9, the structure embossed in the casing or created via a different forming process may have various geometric patterns. The essential factor common to all embodiments is that structures are created which protrude radially inwardly and form the contact points to the matrix. The contact area formed by the contact points is here significantly smaller than the entire inner casing surface. This ensures that despite a durable connection, there are enough unconnected regions between the casing and matrix for thermally induced stresses to be able to be absorbed without destruction.

[0057] The different features of the individual exemplary embodiments can also be combined with one another. The exemplary embodiments in FIGS. 1 to 9 are in particular not of a limiting nature and serve for illustrating the concept of the invention.

[0058] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.