Honeycomb body, particularly a catalyst carrier, provided with opposedly folded metal sheet layers, and its manufacturing process

Honeycomb body, in particular a catalyst carrier body, with counter-entangled sheet metal layers and method for its manufacture.

The present invention relates to a honeycomb body, in particular a catalyst carrier body, according to the preamble of claim 1, as it is preferably applied to motor vehicles.

Such honeycomb body, for. Example, as a catalyst support body and the problems associated with this construction ref. Strain and thermal stress are described for example in EP-A-0121174 and DE-A-33 12 944th For spiral wound and soldered to each other sheet metal layers different products to control the expansion problems are described.

Object of the present invention is that problems bez. to control strain and temperature distribution by a suitable structure, in particular the life of such a catalyst carrier body to increase even under extreme loads.

To achieve this object, a honeycomb body is proposed according to claim 1, which consists of a stack of counter-tangled sheets. This structure performs the intricate shape of the plates and in that these can be connected by joining techniques at their ends to the casing tube, to a very stable, but at elongations also very elastic structure.

As is clear from claim 2, the stack is which devoured at the later honeycomb body has, in cross-section the same area as the later have honeycomb body. This always results depending on the selected height of the stack of circular cross-sectional shapes a certain length. To obtain particularly elastic forms, the stack should preferably have a height of one third to one fifth or even one-ninth of the diameter of the honeycomb body. However, other height ratios are possible. As stated in claim 3, it is also possible according to the inventive idea, to fill elongated round or angular cross-sections of honeycomb bodies in a similar way with structured sheets. The difference in the preparation and the subsequent appearance is mainly in the arrangement of the fixed points and, if necessary, in the form of the stack, as will be explained in more detail with reference to the drawing.

For certain applications, it is possible according to claim 4, in addition to solder the end side honeycomb body according to the invention entirely or at least in partial areas with one another. Since it can not be ensured in all cases that each individual layer contacts the casing pipe at both ends, it may be helpful to the structured metal sheets to be soldered in a narrow edge zone area in addition to each other in order to ensure a secure mount.

according to claim 5 alternating layers of smooth and corrugated metal sheets are also preferred in the present invention. However, this is only one of many possible embodiments, as well as other known structures, z. B. Double wave structures or sheet metal layers are used with omega-shaped corrugations. When using smooth and corrugated sheets, however, it is advantageous according to claim 6, the smooth sheets are slightly longer to manufacture than the corrugated sheets, so that the smooth plates protrude on both sides over the corrugated metal sheets by a short length. The layering of a stack of such sheets of course requires more effort than with plates of the same length, but can be easily accomplished.

There succeed much more easily in such an arrangement, to connect the ends of all corrugated and smooth sheet metal layers to the tubular casing by a joining technique, since no longer ends can slide of smooth sheet metal layers of corrugated sheet metal layers between the casing and ends.

A similar effect can according to claim 7 also be achieved in that the corrugated sheets have straight portions at their ends, which extend approximately in the center between the adjacent smooth metal sheets. In this configuration the ends of all the sheet metal layers touching uniformly the casing, and although they nestle preferably at this on, whereby a solid connection is facilitated.

Another embodiment of the invention it is proposed in claim eighth Such an arrangement is known in principle to filter from the EP-A-0025584. By the use of alternately arranged corrugated metal sheets whose corrugations with each other forms a small angle, various advantages can be achieved, for example, a certain cross-mixing between the individual exhaust gas passages and a slightly irregular front face, which distributes the pressure loss occurring therein over a short length. The application of such a structure was far to realize for spirally wound catalyst carrier body hardly as an oblique undulation is extremely difficult to manufacture. Interlocking toothed rollers with an oblique toothing deform namely generally a metal strip very strong, so that longer distances with a fine uniform oblique curl can hardly be manufactured. In the present invention, however, only relatively short pieces are needed, which can even be produced from a single tooth roller pair. This only need sheets of predetermined length alternately with slight skew to one side or the other to be introduced in a sufficiently wide toothed roller pair, wherein behind the tooth roller pair these plates are brought together again to form a stack. Incidentally arise virtually no changes in the manufacturing process compared to other structured sheets, since the very small angle between the corrugations the handling otherwise hardly affected.

In claim 9 is further proposed that the sheets are to be joined by approximately circumferentially duri Fende welds at their ends to the tubular casing. The shelf life of these compounds may be enhanced by the fact that the weld root sinks slightly by a suitable choice of the welding parameters to the inside, so that in addition creates a form-locking connection between the jacket tube and the ends of the plates.

Possibly cross-sectional shapes are required for certain applications, which s I can not be completely filled with a counter-entangled sheet pile according to the system described previously. Irregular cross-sectional shapes, but especially oval cross-sectional shapes, which have a more favorable stability behavior at relatively high internal pressure, can be prepared according to the invention, however, when fillers are used, which fill out the excess cross-sectional area and in turn may be wound or layered from structured metal sheets.

according to claim 11 a quasi-round-conical (or barrel-shaped, or hemispherical) end face shape can be achieved with the honeycomb bodies according to the invention. Such a shape of the end faces is aerodynamically more favorable than a planar end surface for some applications. Although can not be exactly the same shape reach, as is formed by telescopic pulling apart when spirally wound catalyst carrier bodies, but a similar effect can be achieved, and the more easily, the smaller the height of the stack of sheets used in the manufacture of such a honeycomb body ,

In claims 12, 13, 14, 15 and 16 some production method for producing the honeycomb body of the invention are described by way of example. Claim 12 describes the production of a honeycomb body with a round cross-section, while in claim 13 indicating the modified preparation for elongated cross-sections. In claim 14 additionally provides a method for the production of honeycomb bodies is provided with an oval or irregular cross-sectional area. Except for the engagement of suitably shaped filler pieces in the serving as the starting material sheet stack, the process is no different from those already described. Basically, it would also be possible to make the filling by means of a suitable insertion device after opposing entangling the sheet metal stack.

A further manufacturing variant is described in claim 15th First, a honeycomb body is produced with a round cross section, as described in the features a, b and c of claim 12. The ends of the structured metal sheets can then joining techniques and / or positively be fixed only approximately at the center of the tubular casing in the circumferential direction, preferably, if the already existing friction forces of the steps are not sufficient by around the tubular casing extending circumferentially welded seam. the central region of the honeycomb body so formed is then pushed out to an end face with a punch or the like. The individual plates rotate thereby possibly the only fastening seam at its center, but not break free, so that significant forces can be spent on the deformation. The result is a roughly round-conical, hemispherical or barrel-shaped front side, where the individual channels not extend very accurately in the axial direction of the catalyst carrier body, but this brings no disadvantages. The thus deformed honeycomb body is secured by (further) technical joining and / or positive connections of the sheets to the jacket pipe.

It is also essential that all catalyst carrier bodies according to the invention both ends of each sheet metal layer touching the casing, in principle, whereby a bilateral technical joining each sheet metal layer to the casing tube is possible. Among themselves need the sheet metal layers thereby no longer be necessarily linked, because they can hardly be put out of position because of their opposing entanglement anyway if they are connected by joining techniques laid over the entire length or at several points of its sheath contact line. A technical joining the ends only with the jacket tube according to claim 16 brings additional advantages in the production with them. For example, only needs the inside of the tubular casing to be provided with solder, z. B. in the form of solder powder, paste, or foil, and during the soldering operation only a warm-up of the jacket pipe to the soldering temperature is required. While honeycomb structures can heat a whole very poor, the casing can be brought only much easier to soldering temperature, for example by induction coils or heat radiation from the outside. This is, apart from the greater elasticity of the honeycomb body of the invention, a further substantial advantage for manufacturing.

Embodiments of the invention will become apparent from the invention of schematic cross sections and front views of honeycombs. Show it<ul><li>1 shows a sheet stack at the beginning of the manufacturing process,</li><li>2 shows a prepared therefrom by opposite entanglement catalyst carrier body,</li><li>3 schematically shows the structure of a catalyst carrier body with elongate cross section,</li><li>Figure 4 also a catalyst carrier body with an elongated cross-section but with diagonal, tangled metal layers,</li><li>5 shows the detail V from the edge region of Figure 4,</li><li>6 shows the cutout VI of the edge region of Figure 1,</li><li>Figure 7 shows two layers of sheet metal whose corrugation forms a small angle with each other,</li><li>8 shows the structure of a catalyst carrier body with an oval cross section,</li><li>Figure 9 shows the construction of the filling 81 of Figure 8,</li><li>Figures 10, 11, 12, alternative embodiments of the filler piece and</li><li>13 shows the structure of a catalyst carrier body with a rectangular cross-section.</li></ul>

1 shows a layered made of alternating layers of smooth 1 and corrugated two sheets stack with the height H and length L. Depending on the manufacturing method and the desired, product to be produced cross-section of the stack does not need to start the manufacturing process is not necessarily laminated to a parallelepiped with plane side surfaces 4 to be. Other forms, for. Example, parallelogram or the like, may be more advantageous in manufacturing. Such a stack 3 is grasped by a fork or similar fixing device acting at the fixed points 5, 6 and engulfed in opposite directions by rotating the fork or bending the staple ends. In this way, a shape as it is shown schematically in FIG. 2 So tangled sheets can be fixed by a joining technique in a tubular casing 7, which is an elastic, but stable catalyst support body is formed. Basically, the casing can also be made for example of several segments. To improve the stability of the single sheets 1, 2 may be the front side, preferably in an annular rim portion 8 with each other., Be erlötet. In this way, a stable structure is formed even if individual layers should not touch because of length deviations the jacket pipe.

3 shows a correspondingly produced Kataiysator carrier body is shown with elongated cross-sectional area, this can be produced from a correspondingly longer stack of metal sheets 1, the second Only the fixed points 35, 36 must be selected staggered, which directly yields the desired cross-sectional shape, which fits into a corresponding tubular casing 37th Again, the end faces of all or part of, in particular, be soldered in the edge domain 38th

Another, under resilience and stability considerations more favorable arrangements of the sheet metal layers 1, 2 in an elongated cross-section is shown in FIG. 4 This arrangement can be similar to that previously described processes from a sheet stack by engaging staggered fixed points 45, produced 46th The stack may optionally thereby however also have an approximately parallelogram-shaped cross-section. Also in the embodiment shown in Figure 4, the individual layers need to be technical joining only at their ends to the tubular casing 47th However, a frontal soldering, especially in the border zone area 48 is possible.

It should be noted that the main stack are folded against each other in the embodiments of Figures 2, 3 and 4 generally smooth outer sheet metal layers 9, 39 and 49, so that this layer consists of a double smooth sheet metal layer. This of course can be avoided in principle, by the top or bottom sheet metal layer of the stack is cut next to the fixed points. Of great importance, however, such a measure is not, because the sheets are very thin anyway.

5 shows the detail V from the edge region of Figure 4 is shown enlarged. According to this embodiment, the corrugated sheets 2 at their ends straight sections 52 which extend approximately in the center between the adjacent smooth sheet. 1 Through this embodiment, the ends of all sheets have the same scope for contact with the casing tube so that they nestle on this and a firm connection to the casing pipe can be easily accomplished with different contact angles.

The same result can be achieved by an embodiment according to Figure 6, which shows the detail VI from the edge of the figure 1,. By shortening the corrugated sheet metal layers 2 with the smooth sheet layers 1 by a distance d is also achieved that all the ends of the foil layers touching the casing and can cling to it. In order to produce a uniform stack of longer smooth sheets 1 and shorter corrugated sheets 2, it may be advantageous to provide the smooth sheets at their ends with the grooves of the depth d, are in what used when stacking crossbars between which the corrugated sheets 2 can take their exact position.

Figure 7 shows an alternative structure for the sheet metal layers of the catalyst carrier body according to the invention. Thereafter both metal layers 71, 72 have corrugations which form between them a small angle a. This embodiment has the advantage that no smooth sheet-metal layers are required as intermediate layers, and that in addition the channels formed by the corrugations cross one another and communicate with one another, which results in a swirling of the gases and thus a better contact of the surfaces.

In Figure 8, another embodiment of the invention is shown, which makes it clear that even oval or complicated cross-sections can be filled by the inventive process with sheet metal layers. Again there is the catalyst support structure in principle of a stack oppositely intertwined smooth 1 and 2 corrugated sheets. The entanglement is carried out analogously to the exemplary embodiment, the fixed points 85, 86. However, in order to be able to fill the entire cross-section shown in Figure 4, in addition, a filler 81 is required, which is used before or after the entanglement of the stack therein. Such a filler 81 must be preformed according to the cross-sectional area and yet be replenished may in turn consist of structured metal sheets. In this way, almost any cross-section within a casing tube 87 can be filled.

In Figures 9, 1'0, 11 and 12 suitable filler pieces are presented. The filling shown in Figure 9 piece 81 consists of layered, different long straight 1 and 2 corrugated metal strip. In Figure 10, the filling of spirally convoluted smooth 1 and 2 corrugated metal strip is produced. Figures 11 and 12 show more than filler suitable variants.

In Figure 13 is exemplary of the large number of fillable according to the present invention, cross sections of an end view of a rectangular cross-sectional honeycomb body shown. The fixed points 135, 136 are in turn added to the stack and have both their respective narrow side as to both sides at the same distance h. To prepare such a cross-section formed in several stages of the lamination stack will be prior to insertion into the casing 137 but necessary. According to the invention constructed catalyst carrier body are resistant to thermal alternating loads and can therefore be used with extended life in the close range.