Abstract
A honeycomb body includes wound and/or stacked layers having a geometric center axis, a cavity rotationally symmetrically around the center axis and an outer lateral surface. Each layer extends approximately concentrically around the axis. At least one of the layers is at least partially structured forming channels through which a fluid can flow. The channels extend from the cavity outward to the outer lateral surface at a non-right cone angle to the axis. The channels have a cross-section changing along the channels from inside to outside. At least one structured layer and at least one intermediate layer are alternatingly disposed and helically layered. The structure height of the structured sheet-metal layer forming the channels is substantially constant and channel cross-sectional areas increase from inside to outside. The intermediate layer can be made of simple wires or of specially cut or folded smooth sheet-metal layers.
Claims
1. A honeycomb body, comprising: an inside, an outside and a geometric central axis; wound layers each running concentrically around said central axis and defining an outer lateral surface and a cavity disposed rotationally symmetrically around said central axis, said layers being sheet-metal layers; at least one of said layers being at least partially structured to form a multiplicity of channels through which a fluid can flow; said channels running outwardly from said cavity to said outer lateral surface at a non-perpendicular cone angle relative to said central axis; said channels having a channel cross section varying over a course of said channels from said inside to said outside; at least one intermediate layer being disposed in alternation with said at least one structured layer; and said at least one intermediate layer and said at least one structured layer being layered on top of one other in a helical shape; said at least one at least partially structured sheet-metal layer having a structure defined by individual corrugations each having respective opposing flanks, each of said opposing flanks having a respective flank corrugation for defining an approximately constant structure height of said individual corrugations from said inside to said outside.
2. The honeycomb body according to claim 1, wherein at least said cavity or said lateral surface is cylindrical.
3. The honeycomb body according to claim 1, wherein said cone angle relative to said central axis is 25° to 85° .
4. The honeycomb body according to claim 1, wherein said channels have a constant structure height, and said channels have cross-sectional areas increasing from said inside to said outside.
5. The honeycomb body according to claim 1, wherein said cavity is axially offset relative to said lateral surface, forming a first conical side face and a second hollow conical side face.
6. The honeycomb body according to claim 1, wherein said intermediate layer has slots formed therein so as to extend inward from said outer lateral surface along a profile of said channels.
7. The honeycomb body according to claim 1, wherein said intermediate layer has triangular cutouts formed therein being dimensioned to cause said intermediate layer, after being bent into a final helical shape, to form a closed intermediate layer.
8. The honeycomb body according to claim 1, wherein said intermediate layer is folded along fold lines to generate overlaps with a threefold material thickness and to form a helical profile of said intermediate layer.
9. A honeycomb body assembly, comprising: a cylindrical honeycomb body through which a fluid can flow along a geometric central axis; and a honeycomb body according to claim 1 combined with said cylindrical honeycomb body.
10. The honeycomb body assembly according to claim 9, which further comprises a housing in which said honeycomb bodies are disposed with said geometric central axes aligned.
11. A honeycomb body, comprising: an inside, an outside and a geometric central axis; wound or stacked layers each running concentrically around said central axis and defining an outer lateral surface and a cavity disposed rotationally symmetrically around said central axis; at least one of said layers being at least partially structured to form a multiplicity of channels through which a fluid can flow; said channels running outwardly from said cavity to said outer lateral surface at a non-perpendicular cone angle relative to said central axis; said channels having a channel cross section varying over a course of said channels from said inside to said outside; at least one intermediate layer being disposed in alternation with said at least one structured layer; and said at least one intermediate layer and said at least one structured layer being layered on top of one other in a helical manner; all of said layers being structured sheet-metal layers including alternating structured sheet-metal layers with a coarse structure and intermediate layers with a fine structure, said coarse and fine structures having dimensions differing by at least a factor of 3.
12. A honeycomb body, comprising: an inside, an outside and a geometric central axis; wound or stacked layers each running concentrically around said central axis and defining an outer lateral surface and a cavity disposed rotationally symmetrically around said central axis; at least one of said layers being at least partially structured to form a multiplicity of channels through which a fluid can flow; said channels running outwardly from said cavity to said outer lateral surface at a non-perpendicular cone angle relative to said central axis; said channels having a channel cross section varying over a course of said channels from said inside to said outside; at least one intermediate layer being disposed in alternation with said at least one structured layer; and said at least one intermediate layer and said at least one structured layer being layered on top of one other in a helical manner said layers being sheet-metal layers, and said intermediate layer being at least one wire running in a helical manner between said structured sheet-metal layers.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
(1) FIG. 1 is a diagrammatic, perspective view of a honeycomb body with channels running obliquely from the inside to the outside;
(2) FIG. 2 is a longitudinal-sectional view through the geometric central axis of FIG. 1;
(3) FIG. 3 is a perspective view of a structured sheet metal layer;
(4) FIG. 4 is a perspective view of a first exemplary embodiment of channel forms of the structured sheet-metal layer;
(5) FIGS. 5, 6, 7 and 8 are perspective views illustrating further exemplary embodiments of channel forms of the structured sheet-metal layer;
(6) FIG. 9 is a perspective view of a helically structured sheet-metal layer;
(7) FIG. 10 is a perspective view of the sheet-metal layer of FIG. 9 with an intermediate layer;
(8) FIG. 11 is a perspective view of a sub-region of a honeycomb body composed of a structured sheet-metal layer and a smooth intermediate layer;
(9) FIG. 12 is a perspective and elevational view showing a process of producing a honeycomb body using wires as an intermediate layer;
(10) FIG. 13 is a perspective view showing forms of the wire, that form the intermediate layer, generated during the production process of FIG. 12;
(11) FIG. 14 is a perspective view of a smooth intermediate layer with triangular cutouts;
(12) FIG. 15 is a perspective view showing the construction of a honeycomb body with a cutout smooth intermediate layer;
(13) FIG. 16 is a plan view showing the final form of the cutout smooth intermediate layer after installation;
(14) FIG. 17 is a plan view showing a slotted smooth intermediate layer in its final form;
(15) FIG. 18 is a perspective view showing a folded smooth intermediate layer, partially in its final form; and
(16) FIG. 19 is a perspective view showing a combined configuration of a honeycomb body with a cylindrical honeycomb body.
DETAILED DESCRIPTION OF THE INVENTION
(17) Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a diagrammatic illustration of a basic construction of an exemplary embodiment of a honeycomb body 1 according to the invention with structured sheet-metal layers 2 as a major constituent part, in which the structured sheet-metal layers extend approximately concentrically around a geometric central axis 4 and each individually approximately have the shape of a funnel. A cylindrical cavity 5 is situated in the interior of the honeycomb body. The structured sheet-metal layers 2 are delimited at the outside by an outer lateral surface or jacket surface 6.
(18) FIG. 2 shows a diagrammatic longitudinal section through the geometric central axis 4 of FIG. 1. In this case, it can be seen that numerous channels 7 lead obliquely outward from the cavity 5, specifically with a cone angle a with respect to the direction of the geometric central axis 4, wherein all of the channels end at the outer lateral surface 6. In this way, a conical side face 11 and a hollow conical side face 10 are formed.
(19) FIG. 3 shows, once again in a diagrammatic illustration, a perspective view of a single structured sheet-metal layer 2, which extends in funnel-shaped form around the cavity 5. In this case, it is also possible to see the particular channel shape selected in this exemplary embodiment, which is shown in more detail in FIG. 4.
(20) FIG. 4 illustrates the general geometric problem in forming, from substantially planar sheet-metal strips, structures which have the same structure height H over the entire width of the sheet-metal strip but, despite the same amount of material being used around the perimeter, have a smaller cross section at one end than at the other end, thus rendering it possible to produce the desired funnel shape of the structured sheet-metal layer 2. The channels 7 of the structured sheet-metal layer 2 that are formed have a channel cross-sectional area 7i, 7a (see FIG. 6) that increases in the outward direction.
(21) FIGS. 5, 6, 7 and 8 show another exemplary embodiment according to the invention for structures which have varying channel cross-sectional areas over the course thereof while having a constant perimeter length of a cross section. FIGS. 5 and 6 each show the same part of a structured sheet-metal layer 2 but in different viewing directions. FIGS. 7 and 8 show, on an enlarged scale, the two ends of the structures shown in FIGS. 5 and 6. In this case, the structured sheet-metal layer 2 has channels which have a relatively small inner channel cross-sectional area 7i and a relatively large outer channel cross-sectional area 7a. This is achieved by way of a flank corrugation which, as an inner flank corrugation 2i, has corrugation peaks and corrugation troughs running relatively close together, whereas an outer flank corrugation 2a is drawn out to a great extent in such a way that the corrugation troughs and corrugation peaks run in an almost flat manner. The structure height H of the structured sheet-metal layer 2 is, however, the same at both ends of the channels.
(22) In the following figures, for simplicity, the illustrations show not funnel-shaped, conical layers but flat structures on which the details of the invention can be seen more clearly. In accordance with the present invention, however, it is the intention for the layers to also be funnel-shaped, as illustrated in FIGS. 1 and 3, in addition to the characteristics illustrated and described herein. It is, however, pointed out that the embodiments and production methods described in FIGS. 9-18 are basically also suitable for the production of honeycomb bodies with channels running purely radially, as is readily apparent from the illustrations. Such configurations can also partially achieve the stated objects, in a manner according to the invention.
(23) FIGS. 9, 10 and 11 illustrate how a structured sheet-metal layer 2 can be wound or stacked with the aid of a smooth intermediate layer 3 to form a helical structure, wherein the intermediate layer 3 prevents the structures of the structured sheet-metal layer 2 from sliding into one another during the layering process. In this case, FIG. 11 illustrates a sub-region of a honeycomb body thus formed, having a cavity 5 and an outer lateral surface 6, in which the helical configuration of the structured sheet-metal layer 2 and the intermediate layer 3 can be seen. In the illustration, only the additional funnel-shaped form has been omitted. This is, however, intended to be provided according to the invention, but has been flattened in the illustration for improved clarity.
(24) FIG. 12 shows another exemplary embodiment of the invention in which the intermediate layer is formed by two wires 8, which preferably have a thickness of 0.1 to 1 mm. As is diagrammatically indicated, a helically structured sheet-metal layer 2 is formed from a smooth sheet-metal band, normally wound in the form of a so-called coil, by way of a suitable corrugation process, wherein inlay grooves 9 may be provided in the inner and outer region during the structuring process. During the helical layering process, in each case one wire 8 from a diagrammatically indicated storage roll is laid into the inlay grooves 9, in such a way that the two wires 8 form an intermediate layer, as long as the inlay groove 9 is not deeper than the thickness of the wires 8. In this case, the wires 8, which must be thin in relation to the structure height H of the structured sheet-metal layer 2, have the effect that the structured sheet-metal layers layered one on top of the other cannot slide into one another. This configuration has the additional advantage that larger channel cross sections are formed, because the channels are not delimited by a continuous intermediate layer.
(25) FIG. 13 illustrates once again the forms of the wires 8 generated during the production process according to FIG. 12, in which the wires in turn run in a helical fashion in the completed honeycomb body.
(26) FIG. 14 illustrates another smooth intermediate layer 13, cut out in accordance with the invention, in which approximately triangular cutouts 12 are provided, in such a way that deformation to form a helical intermediate layer is easily possible. This is illustrated in FIG. 15, in which the cut-out smooth intermediate layer 13 has already partly been brought into its final form. It can be seen that the triangular cutouts 12 are specifically dimensioned in such a way that, in the finished state, a practically closed intermediate layer 13 is formed, which in turn serves to fully prevent structures of the structured sheet-metal layers 2 from sliding into one another. In the case of this production method, however, material waste is produced in the form of the triangular cutouts 12. In exchange, however, as illustrated once again in FIG. 16, a practically closed helical, cut-out, smooth intermediate layer 13 is formed, the individual segments of which are coherent at the outside and, at the inside, leave the cavity 5 free.
(27) An alternative embodiment is shown in FIG. 17, which illustrates a slotted smooth intermediate layer 23. In this case, slots run outward from a coherent region surrounding the cavity 5, in such a way that no waste material is produced, but triangular slots that open from the inside outward are provided. It is nevertheless possible for a slotted smooth intermediate layer 23 of this type to substantially prevent structures of adjacent structured sheet-metal layers from sliding into one another.
(28) A further form of a folded smooth intermediate layer 33 is illustrated in FIG. 18. Since sheet-metal layers with a thickness of 20 μm to 120 μm are typically used in honeycomb bodies, it is not of great significance for the final form if sheet-metal layers overlap in individual regions. This fact is utilized in the embodiment according to FIG. 18, in which the intermediate layer 33 is folded along fold lines 32, so that approximately triangular shapes are generated in an overlap region 31. In this way, depending on the number of fold lines 32, it is possible to produce the desired form of an intermediate layer from a smooth sheet-metal strip in helical form or in helical and funnel-shaped form in a highly effective manner.
(29) It is thus possible for honeycomb bodies according to the invention to be mass-produced from sheet-metal strips by helically layering structured sheet-metal layers 2 and intermediate layers 3.
(30) FIG. 19 illustrates how a honeycomb body 1 according to the invention can be disposed with a conventional cylindrical honeycomb body 16 in a common housing 20. A fluid to be purified, in particular exhaust gas of an internal combustion engine, can flow from an inlet 14 into the cavity 5 of the conical honeycomb body 1 according to the invention, wherein a part of the fluid passes through channels 7 to the outer lateral surface 6. This part of the fluid is collected in a collecting chamber 17, is conducted around the outside of the cylindrical honeycomb body 16, and then passes into a mixing chamber 18 and to an outlet 19. Another part of the fluid flows from the cavity 5 into the cylindrical honeycomb body 16 which includes partially illustrated axial channels, in such a way that this part of the fluid also passes into the mixing chamber 18 and to the outlet 19. It is particularly advantageous for the conical honeycomb body 1 and the cylindrical honeycomb body 16 to be disposed in alignment along a common geometric central axis 4. This embodiment is an example for possible uses of conical honeycomb bodies for the expedient utilization of existing structural space and for the reduction of pressure losses while providing a predefined surface area for catalytic conversion or for separating off particles.
(31) Altogether, the invention permits flexible use, in a manner adapted to different installation situations, of conical honeycomb bodies on their own or in conjunction with other honeycomb bodies for the treatment of fluids, in particular for the purification of exhaust gases of internal combustion engines, in particular in motor vehicles.
