Honeycomb structure and method for producing a structured layer

Abstract

The invention relates to a honeycomb structure (1) comprising at least one stack (7), which is formed at least by a first layer (8) having a corrugated structure (9). The first layer (8) extends between a first end face (10) located on the fluid inlet side (2) and a second end face (11) located on the fluid outlet side (3) along a width direction (12) which is parallel to the central axis (4). The corrugated structure (9) of the first layer (8) has a plurality of wave troughs (13) and wave crests (14) running parallel to one another as a primary structure, said troughs and crests each extending, with respect to the width direction (12), at an angle of inclination (15) which is greater than zero angular degrees and at most 15 angular degrees along a running direction (16), and the corrugated structure (9) has at least one secondary structure which comprises an inversion of the primary structure in the form of intermediate wave crests (18) and intermediate wave troughs (19) that cross the wave troughs (13) and wave crests (14) of the second layer (20) in contact zones (21). The invention also relates to a method for producing a structured layer (8, 20).

Description

[0001] Honeycomb structure and method for producing a structured layer

[0002] The present invention relates to a honeycomb structure and a method for producing a structured layer.

[0003] The honeycomb structure extends in particular between a fluid inlet side and a fluid outlet side along a central axis, with channels extending between these sides so that a fluid can flow through the honeycomb structure. The honeycomb structure comprises at least one stack formed at least by a first layer having a corrugated structure. The first layer extends between a first end face arranged on the fluid inlet side and a second end face arranged on the fluid outlet side along a width direction parallel to the central axis. The corrugated structure of the first layer has a plurality of mutually parallel wave troughs and wave crests as a primary structure, each of which extends at an inclination angle relative to the width direction of greater than zero angular degrees and at most 15 angular degrees along a direction of extension.

[0004] The stack and the channels are formed by arranging another structured region of the same first layer or by arranging a structured second layer on the first layer; wherein the other region of the first layer or the second layer is structured such that the superimposed wave troughs and wave crests intersect, so that a contact zone between the wave troughs and the wave crests is delimited along the direction of extension.

[0005] The layer having a corrugated structure is used, for example (but possibly not exclusively), to form a honeycomb structure of a honeycomb body for exhaust gas aftertreatment, such as is used in particular as a catalyst carrier body in the exhaust systems of mobile internal combustion engines. Such a honeycomb structure or honeycomb body provides, in particular, a large surface area on which catalytically active material is positioned and brought into contact with the exhaust gas flowing through the honeycomb body. The invention finds particular application in exhaust gas purification in motor vehicles or in stationary or other mobile systems.

[0006] A variety of different honeycomb designs for exhaust aftertreatment have already been proposed. A basic distinction is made between ceramic and metal honeycombs (steel or non-ferrous material). However, honeycombs can also be made of plastic materials.

[0007] A honeycomb body can be constructed from smooth and / or structured layers or sheet metal foils. These layers can be layered, wound, and / or twisted, and finally placed within a housing of the honeycomb body, forming a plurality of channels through which the exhaust gas can flow. The channels can extend, for example, in a straight line, twisted, and / or oblique manner between the end faces of such a honeycomb body.

[0008] With the goal of achieving the closest possible contact between the exhaust gas and the walls of the honeycomb structure, or rather the catalytic coating placed there, measures have already been proposed to reduce laminar flow of the exhaust gas through the honeycomb structure. For example, openings can be provided in the channel walls to form communicating channels. It is also known to provide deflection structures, guide vanes, etc., as secondary structures in the channels to achieve targeted flow deflection within the channels, pressure differences between the channels, or similar.

[0009] From DE 102012 004 918 A1 a honeycomb body is known in which the structured layers have a corrugated structure, wherein layers arranged adjacent to one another have intersecting corrugated structures.

[0010] In a honeycomb structure with intersecting corrugated structures, the channels of the structured layers exhibit a defined angle of inclination relative to the width direction. Alternating stacking of the structured layers, each with opposite channel orientation, creates a three-dimensional pattern of contact zones in which adjacent corrugated structures intersect and touch, eliminating the need for (non-structured) smooth foils between the corrugated (structured) layers. To ensure thermomechanical durability during operation, the layers can be bonded to the housing or to each other in a form-fitting or material-fitting manner. In this context, one example of a solder preparation process is a glue-water mixture that is drawn axially into the honeycomb structure at the contact points between two adjacent layers by capillarity. Welding processes represent another joining technology.Contact points arranged on the front side between two layers can be connected in a material-to-material manner.

[0011] The connections between the layers in the contact zones influence the expansion or expansion behavior of the honeycomb body or honeycomb structure and therefore represent a significant factor influencing the durability of the honeycomb body.

[0012] In honeycomb structures with intersecting corrugations, the contact situation between adjacent structured layers changes continuously across the cross-section of the honeycomb structure. This creates areas where the wave crests and troughs of two adjacent structured layers contact each other at the front, and areas where the contact zone is spaced a few millimeters from the front, i.e., offset along the central axis.

[0013] A disadvantage of the current design is that, in the absence of a (non-structured) smooth layer, the methods for bonding, such as soldering or welding, are only suitable to a limited extent. The joining methods mentioned above, for example, cannot guarantee that the required number of contact zones in such honeycomb structures are bonded together or that sufficient connections are ensured in the area of ​​the end faces. A further disadvantage is the manufacturing process for the structured layers. These can be formed using a corrugated bending process using structured corrugated rollers.In forming processes, especially with inclined cell channels, the achievable embossing height, embossing geometry and rounding radii are limited due to damage (cracks or holes, or similar) of the layers, especially when additionally combined with secondary structures.

[0014] The object of the present invention is to at least partially solve the problems cited with reference to the prior art. In particular, a honeycomb structure is to be provided that is particularly suitable for the targeted formation of contact zones, so that a predictable expansion behavior and the longest possible durability of the honeycomb structure can be generated using known joining methods (soldering methods, welding methods). In addition, a method for producing a structured layer is to be proposed by which the manufacturing process of diagonally corrugated layers is to be improved with regard to design freedom (embossing height, embossing geometry and rounding radii, etc.) and cycle time. In particular, this is to enable critical geometries, such as a high embossing and corrugation height and small rounding radii.

[0015] A honeycomb structure having the features according to claim 1 and a method having the features according to claim 9 contribute to solving these problems. Advantageous further developments are the subject of the dependent claims. The features listed individually in the claims can be combined with one another in a technologically expedient manner and can be supplemented by explanatory facts from the description and / or details from the figures, whereby further embodiments of the invention are shown.

[0016] A honeycomb structure is proposed which extends between a fluid inlet side and a fluid outlet side along a central axis, with channels extending between these sides so that a fluid can flow through the honeycomb structure. The honeycomb structure comprises at least one stack which is formed at least by a first layer having a corrugated structure. The first layer extends between a first end face arranged on the fluid inlet side and a second end face arranged on the fluid outlet side along a width direction parallel to the central axis. The corrugated structure of the first layer has a multiplicity of mutually parallel wave troughs and wave crests as a primary structure, each of which extends at an inclination angle relative to the width direction of greater than zero angular degrees and at most 15 angular degrees along a direction of extension.

[0017] The corrugated structure has at least one (type of) secondary structure comprising an inversion of the primary structure, each extending over a distance of at most 20%, in particular over a distance of at most 10%, preferably over a distance of at most 5%, along the direction of travel between the end faces. The inversion forms an intermediate wave crest from a wave trough, or an intermediate wave trough from a wave crest. The stack and the channels are formed by arranging another structured region of the same first layer or by arranging a structured second layer on the first layer.The other region of the first layer or the second layer are structured in such a way that the superimposed wave troughs, wave crests, intermediate wave crests and intermediate wave troughs intersect, so that a contact zone between the wave troughs and intermediate wave troughs on the one hand and the wave crests and intermediate wave crests on the other hand is limited along the direction of travel.

[0018] In particular, the first (and / or second) layer extends between the first end face and the second end face along the width direction and transversely thereto along a longitudinal direction from a first end to a second end. In particular, the first (and / or second) layer is (substantially) rectangular. In particular, the extension of the layer along the extension direction is greater than along the width direction.

[0019] In particular, the entire first (and / or second) layer is structured, i.e. it has the corrugated structure over the entire extent in the width direction and in the extension direction (i.e. in particular no smooth / unstructured areas).

[0020] In particular, the width of the layer is between 5 and 1,000 millimeters, preferably less than 200 millimeters.

[0021] In particular, a material thickness of the first layer (in a height direction extending transversely to the width and extension direction) is between 20 pm and 2 millimeters, in particular at most 1.0 or even at most 0.5 millimeters.

[0022] In particular, the corrugated structure has an amplitude (i.e. a maximum extension of the structured layer in the height direction) between 0.5 millimeters and 10 millimeters, in particular of a maximum of 5 millimeters.

[0023] In particular, the wave troughs and wave crests each extend at an inclination angle relative to the width direction of greater than one degree, preferably greater than 2 or even 3 degrees. In particular, the first inclination angle is at most 15 degrees, preferably at most 12, at most 10, or even at most 8 degrees. If such layers are arranged on top of one another with intersecting directions, the angles between the contacting wave troughs and wave crests correspond to the sum of the inclination angles of each layer.

[0024] By arranging the layers on top of each other, the honeycomb structure is formed. For this purpose, the stack can be used with the layers stacked exclusively on top of each other, or the stack can be folded and / or wound and / or twisted. Such honeycomb structures are generally known.

[0025] A honeycomb structure produced in this way can be arranged in a housing and thus form a honeycomb body.

[0026] The honeycomb body or honeycomb structure can fundamentally have various shapes, in particular a round, oval, polygonal or similar cross-section. Such a honeycomb body is often designed with a tube-like housing. When used for exhaust gas aftertreatment, an exhaust gas / fluid regularly enters the honeycomb body via a fluid inlet side (side) and exits again via a fluid outlet side (side). The fluid inlet / outlet sides, which are preferably arranged essentially parallel or inclined to one another, regularly define the length of the honeycomb body in the direction of the central axis of the honeycomb body, which penetrates both sides of the honeycomb body and is arranged perpendicularly and centrally to at least one, preferably both sides.

[0027] In particular, with the inversion (of a limited region of the primary structure) forming the secondary structure, an intermediate wave crest is formed from a partial region of a wave trough or an intermediate wave trough is formed from a partial region of a wave crest.

[0028] Inversion particularly comprises an exclusive deformation of the primary structure. Thus, the shape of the secondary structure (with an inclined surface) gradually transitions into the shape of the primary structure, particularly along the direction of the channels. The gradual transition of the shape of the secondary structure into the shape of the primary structure provides a surface that is inclined relative to a fluid flowing through the honeycomb structure along the direction of the channel. If necessary, the inversion can be separated from the primary structure by a separating cut, which particularly runs (at least or exclusively) transversely to the direction of the channel. As a result of the separating cut, which is particularly limited to one channel along the longitudinal direction, an additional edge is created within the honeycomb structure, which can be acted upon by a fluid flowing through the honeycomb structure.

[0029] As a result of the separating cut, the formation of an inclined surface is not necessary. This can, for example, reduce the flow resistance of the honeycomb structure to a fluid flowing through it.

[0030] With each intermediate wave crest or intermediate wave trough, an additional contact zone (in addition to the contact zones of the primary structure) can be formed between the wave troughs and intermediate wave troughs on the one hand and the wave crests and intermediate wave crests on the other, which is also limited along the direction of travel (like the contact zones formed by the primary structure).

[0031] The secondary structure can be used to specifically provide additional contact zones where soldering or welding connections can be created.

[0032] In particular, the at least one secondary structure (i.e., a respective inversion) extends to one end face of the respective layer. This allows, in particular, a further contact zone to be formed or provided near the end face or directly at the end face. This allows, in particular, the creation of further (materially bonded) connections in the area of ​​the end faces, using known joining methods.

[0033] In particular, the at least one secondary structure (i.e., a respective inversion) is arranged at a distance from the end faces of the respective layer. This allows, in particular, a further contact zone to be formed or provided near (but not on) the end face. This allows, in particular, the creation of further (materially bonded) connections in the area of ​​the end faces, using known joining methods.

[0034] In particular, in a cross-section extending transversely to the direction of travel, a contact area of ​​the secondary structure suitable for forming a contact zone with an adjacent layer is larger than a contact area of ​​the primary structure.

[0035] In particular, the primary structure comprises, for example, a sinusoidal (or differently or similarly shaped) corrugation of the layer. The, for example, sinusoidal corrugation has alternating maxima and minima, particularly along the longitudinal direction, through which the amplitude is formed. In particular, the inversion can, for example, form a flattened maximum or minimum of the corrugation (i.e., not point-shaped in cross-section, but linear along the longitudinal direction), so that a contact area formed by the linear maximum or minimum is larger than the contact area formed by the point-shaped maximum or minimum.

[0036] In particular, in each wave trough and / or in each wave crest of the first (and / or second) layer, (only or at least) one secondary structure is provided.

[0037] In particular, a layer may have exclusively interwave crests or exclusively interwave troughs as secondary structures. Alternatively, a layer may have both types of secondary structures, i.e., interwave crests and interwave troughs.

[0038] In particular, the secondary structures are arranged at the same position relative to the width direction (i.e., e.g., at the same distance from an end face of the respective layer). In particular, a plurality of secondary structures spaced apart from one another along the direction of travel are provided on the first layer. In particular, at least in part, several secondary structures are provided per wave trough or wave crest, which are spaced apart from one another along the direction of travel. In particular, this allows targeted (material-bonded) connections between adjacent layers to be created or provided at specific locations of the honeycomb structure.

[0039] In particular, a plurality of alternately arranged intermediate wave crests and wave crests are provided next to one another on the first (and / or second) layer along a longitudinal direction running transversely to the width direction, wherein a plurality of alternately arranged intermediate wave troughs and wave troughs are provided next to one another along the width direction (and / or direction of extension) offset therefrom along the longitudinal direction.

[0040] In particular, the intermediate wave crests and intermediate wave troughs are provided alternately along the longitudinal direction (if necessary, offset or spaced apart from each other along the width direction and / or direction of travel).

[0041] In this case, "offset" along the width direction means, in particular, that the intermediate wave crests and troughs are not aligned next to one another along the longitudinal direction. "Spaced apart" along the width direction means, in particular, that the intermediate wave crests and troughs are not only not aligned along the longitudinal direction, but also do not overlap one another.

[0042] In particular, the intermediate wave crests and intermediate wave troughs are arranged offset from one another and / or spaced from one another along the width direction and / or direction of extension.

[0043] The proposed honeycomb structure ensures a reproducible and high number of connection points per cross-sectional area (transverse to the width direction) as a function of the cell density (of the honeycomb structure). In particular, the connection quality at the connection points can be improved (e.g., through larger contact areas or contact zones). In particular, the connection quality in the contact zones or at the contact surfaces between adjacent layers can be improved in gluing processes with a capillary effect or in welding processes. In particular, the provision of the secondary structure can create additional support points (contacts between adjacent layers), so that the honeycomb structure is improved in terms of mechanical stability and with regard to a constant prestress that is evenly distributed across the sides of the honeycomb structure (fluid inlet side, fluid outlet side).In addition, the risk of damage to the honeycomb structure during manufacturing and operation can be reduced. Furthermore, the volume-specific effectiveness of the honeycomb structure is significantly increased with regard to any exhaust gas purification or treatment. In particular, the heating behavior of the honeycomb structure can be improved by homogenizing the thermal mass and improving heat transfer between the layers. In particular, the provision of the secondary structure results in only a moderate increase in backpressure (when a fluid flows through the honeycomb body).

[0044] In particular, soldered or welded joints (hereinafter referred to as joints) are present at a maximum of 20%, preferably at a maximum of 10%, particularly preferably at a maximum of 5%, of the contact zones of the honeycomb structure. These are produced, in particular, during or after the production of the honeycomb structure. In particular, these joints are distributed substantially uniformly over a cross-section of the honeycomb structure extending transversely to the central axis. However, there may also be a deliberately created, uneven distribution or a pattern of distribution of the joints.

[0045] In particular, (at least some of the cohesive) connections of the honeycomb structure are arranged at a distance of no more than 10 millimeters from the respective nearest end face of a layer. In particular, at least 30%, and in particular at least 45%, of these connections extend to the end face.

[0046] In particular, at least 90% of all (material-bonded) connections, in particular 100%, are located at a distance of at most 20 millimetres, preferably of at most 15 millimetres, particularly preferably of at most 10 millimetres, from the (nearest) end faces.

[0047] In particular, each (material-bonded) connection extends along a direction parallel to the central axis over a maximum length of no more than 10 millimetres, in particular no more than 5 millimetres.

[0048] A method for producing a structured layer having a corrugated structure is further proposed. The layer extends between a first end face and a second end face along a width direction and transversely thereto along a longitudinal direction from a first end to a second end. The corrugated structure has a multiplicity of mutually parallel wave troughs and wave crests as a primary structure, each of which extends at an inclination angle relative to the width direction of greater than zero angular degrees and at most 15 angular degrees along a direction of extension. Furthermore, the corrugated structure has at least one secondary structure which comprises an inversion of the primary structure, each of which extends over at most 20% of a distance present along the direction of extension between the end faces.With the inversion, an intermediate wave crest is formed from a wave trough or an intermediate wave trough is formed from a wave crest.

[0049] The method comprises at least the following steps: a) providing a rolling device, at least comprising a first pair of rollers and a second pair of rollers; b) feeding the still unstructured layer to the rolling device; c) forming the layer by passing the unstructured layer through the first pair of rollers and forming an intermediate shape of the corrugated structure; d) forming the layer having the intermediate shape by passing the layer through the second pair of rollers and forming the corrugated structure.

[0050] The above (non-exhaustive) classification of process steps into a) to d) is primarily intended to serve as a distinction and does not enforce any order and / or dependency. The frequency of the process steps, e.g., during setup and / or operation of the rolling device, may also vary.

[0051] It is also possible that procedural steps overlap, at least partially. In particular, steps a) to d) are performed in the order listed.

[0052] Basically, rolling devices are known, in particular those in which the rollers of a pair of rollers mesh with each other and thus, when a layer is passed through the pair of rollers, structure the layer.

[0053] In this case, at least two, but possibly more than two, forming steps are proposed. This allows the intended structures (primary structure or secondary structure) to be reproducibly imprinted onto the corresponding layers.

[0054] Step a) of the method comprises, in particular, providing a rolling device with at least two, preferably three or even four, pairs of rollers. Each pair of rollers comprises (at least or exactly) two rollers that mesh with each other.

[0055] Step b) of the process comprises in particular feeding the still unstructured (i.e. smooth) layer to the rolling device.

[0056] Step c) particularly comprises forming the layer by passing the unstructured layer (supplied according to step b) through the first pair of rollers. The layer is formed by the intermeshing surfaces of the rollers, and the intermediate shape of the corrugated structure is imprinted on the layer. Within the scope of step c), for example, only certain parts of the corrugated structure (e.g., only the primary structure or only the secondary structure, and / or parts thereof) and / or only partially formed structures (e.g., with a lower amplitude, etc.) can be produced.

[0057] Step d) comprises, in particular, forming the layer having the intermediate shape by passing the layer through the second pair of rollers and forming the corrugated structure. In particular, the layer is in a predetermined state after step d), i.e., all primary and secondary structures are produced in a fully formed state.

[0058] In particular, several steps c) can be provided, with each subsequent step c) further forming a layer with an already created intermediate shape (created by the previous step c). Steps c) then constitute the intermediate forming stages, and step d) the final forming stage of the successive forming of the layer.

[0059] Using a multi-stage forming process, the diagonally corrugated layer can be formed step by step until it achieves the desired shape. The individual forming steps can be carried out directly one after the other in a production line (with the layer undergoing steps c) and d) at least partially simultaneously, but with different sections of the layer) or independently of one another. With an increasing number of forming steps, the shape of the layer is successively increased. In contrast to single-stage corrugation (no step c), only step d)), in each sub-step there is the possibility for the material of the layer to "flow" in the strip travel direction (i.e. conveying direction of the layer, here particularly in the longitudinal direction). This makes a higher overall degree of forming of the layer possible.

[0060] In particular, this allows for more freedom in the geometric design of the layer (degree of deformation, radius design, etc.). In particular, it also allows for a continuous forming process (i.e., in which the layer undergoes steps c) and d) at least partially simultaneously) for the proposed corrugated structure (with inclined channels), thus reducing cycle times and manufacturing costs.

[0061] In particular, the intermediate form (after the one or first step c)) has a maximum amplitude of the corrugated structure which is at most 80%, in particular at most 70%, preferably at most 50%, of the maximum amplitude of the corrugated structure of the structured layer (after step d)).

[0062] A honeycomb body is further proposed, comprising at least the described honeycomb structure and / or the layer produced by the described method with a corrugated structure. To form a honeycomb structure through which a fluid can flow from the fluid inlet side to the fluid outlet side of the honeycomb body, the first layer is arranged in a stack by folding itself or with at least one other structured layer. If necessary, the honeycomb structure is formed by additionally winding, twisting, or folding the stack. Multiple stacks can also be used for this purpose.

[0063] The described structured layers (without secondary structure) and the honeycomb body or honeycomb structure are generally known. In this regard, reference is made to the known designs of layers and honeycomb bodies or honeycomb structures.

[0064] The honeycomb structure is intended primarily for exhaust aftertreatment. Please refer to the explanations in the introduction.

[0065] The at least one layer can, for example, be arranged in a spiral manner around the central axis. In particular, two layers or a multiple thereof are used, with a pair of layers possibly having the same structure (type, size, etc.), but with a different orientation of the corrugated structure, so that the troughs and crests of the contacting layers intersect.

[0066] The corrugated structure of the layer is preferably formed over its entire length, i.e., between the first end face and the second end face. The corrugated structure is formed by elevations (wave crests) and depressions (wave troughs). Wave crests and troughs alternate regularly along the length of the layer. The wave crests and troughs can form a type of sinusoidal corrugation, zigzag shape, or similar in cross-section.

[0067] The arrangement of the structure, i.e. the wave crests and troughs in the honeycomb body, is now such that they run at an angle to the central axis. This creates channel sections for a fluid that do not run parallel to the central axis, but at an angle to it. If an exhaust gas flow or a fluid flow hits an end face of the honeycomb structure or a fluid inlet side of the honeycomb body perpendicularly, the exhaust gas / fluid is initially split because it penetrates the channel openings formed by the wave crests and troughs and is then deflected inside the honeycomb body. The design of the structure is particularly noteworthy in that the wave crests and troughs in adjacent areas (viewed in the radial direction relative to the central axis) are at different angles or have a different orientation. For example, ifIf there is a deflection to the right in one area, it is preferred that there is a deflection to the left in the area further inside, or vice versa. It is very particularly preferred that this alignment or orientation, viewed in the radial direction, always alternates. This leads in particular to the wave crests and wave troughs lying on top of one another at least partially, and preferably at no point on the honeycomb body, in a linear manner, but rather crossing one another and thus essentially only forming point-like support points or contact zones with one another. This results in a structure in which the partial flows of the exhaust gas / fluid are permanently deflected and can flow into adjacent wave crests or wave troughs, in particular in a zigzag manner. Furthermore, the use of the honeycomb body or the layer in an exhaust system is proposed, e.g. of a motor vehicle or a stationary system which has an internal combustion engine with an exhaust system.The exhaust system comprises at least one catalyst carrier or a particle separator constructed with a honeycomb structure as described herein. The catalyst carrier and / or the particle separator may have a catalytically active coating.

[0068] In particular, at least one data processing system is provided which has means which are suitably equipped, configured or programmed to carry out the method for producing the layer or which carries out the method.

[0069] In particular, the device provided for carrying out the method for producing the honeycomb structure comprises a data processing system, e.g. a control device, which has means for carrying out the steps of the method and / or which has means that are suitably equipped, configured or programmed to carry out the steps of the method or that carry out the method.

[0070] The means include, for example, a processor and a memory in which instructions to be executed by the processor are stored, as well as data lines or transmission devices that enable the transmission of instructions, measured values, data or the like between the elements mentioned.

[0071] The "means" can in particular comprise one or more of the following components: controller(s), microcontroller, data memory, data connection, display devices (such as a display), counter or timer, at least one further sensor, an energy source, etc. A computer program is further proposed, comprising instructions which, when the computer program is executed by a computer, cause the computer to carry out the described method or the steps of the described method.

[0072] Furthermore, a computer-readable storage medium is proposed, comprising instructions which, when executed by a computer, cause the computer to carry out the respective described method or the steps of the respective described method.

[0073] The statements regarding the method are particularly transferable to the honeycomb structure, the honeycomb body, the use, the data processing system and / or the computer-implemented method (i.e. the computer program and the computer-readable storage medium) and vice versa.

[0074] The use of indefinite articles ("a," "an," "one," and "another"), particularly in the patent claims and the description reproducing them, is to be understood as such and not as a numeral. Terms or components introduced accordingly are therefore to be understood as appearing at least once and, in particular, as being able to appear multiple times.

[0075] As a precaution, it should be noted that the numbers used here ("first", "second", ...) primarily serve (only) to distinguish between several similar objects, quantities or processes, and therefore in particular do not necessarily specify any dependency and / or sequence of these objects, quantities or processes. Should a dependency and / or sequence be necessary, this is explicitly stated here or it will be obvious to the person skilled in the art upon studying the specifically described embodiment. If a component can occur multiple times ("at least one"), the description of one of these components can apply equally to all or part of the majority of these components, but this is not mandatory. The invention and the technical environment are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments cited.It should be noted that the figures, and in particular the proportions depicted, are only schematic. They show:

[0076] Fig. 1 : a section of a honeycomb body formed by the layers in a perspective view, partly in section;

[0077] Fig. 2: the section according to Fig. 1 in a view along a central

[0078] axis of the honeycomb body;

[0079] Fig. 3: an example of a honeycomb body with the layers according to Fig. 1 and

[0080] Fig. 2;

[0081] Fig. 4: a first layer in perspective view;

[0082] Fig. 5: a second layer in perspective view;

[0083] Fig. 6: a design variant of a layer in perspective view;

[0084] Fig. 7: the position according to Fig. 4 to 6 in a view along the direction of travel;

[0085] Fig. 8: a section of a honeycomb structure formed by the layers according to Figs. 4 and 5 in a perspective view; and

[0086] Fig. 9: The method for producing the layer using a rolling device in a side view. Fig. 1 shows a section of a honeycomb body 34 formed by the layers 8, 20 in a perspective view, partially in section. Fig. 2 shows the section according to Fig. 1 in a view along a central axis 4 of the honeycomb body 34. Fig. 3 shows a honeycomb body 34 with the layers 8, 20 according to Fig. 1 and Fig. 2. Figures 1 to 3 are described together below.

[0087] The honeycomb body 34 has a honeycomb structure 1 that extends between a fluid inlet side 2 and a fluid outlet side 3 along a central axis 4. Channels 5 extend between these sides 2, 3, so that a fluid 6 can flow through the honeycomb structure 1. The honeycomb structure 1 comprises a stack 7 formed by a first layer 8 and additionally by a second layer 20, each having a corrugated structure 9, wherein the layers 8, 20 extend between a first end face 10 arranged on the fluid inlet side 2 and a second end face 11 arranged on the fluid outlet side 3 along a width direction 12 parallel to the central axis 4 and along a longitudinal direction 23 running transversely to the central axis 4 between a first end 24 and a second end 25 (see Fig. 6).

[0088] The corrugated structure 9 of the layers 8, 20 comprises a plurality of mutually parallel wave troughs 13 and wave crests 14 as a primary structure, each extending at an inclination angle 15 relative to the width direction 12 of greater than zero degrees and at most 15 degrees along a direction 16. If such layers 8, 20 are arranged on top of one another, angles arise between the contacting wave troughs 13 and wave crests 14 that correspond to the sum of the inclination angles 15 of each layer 8, 20.

[0089] The layers 8, 20 each have a material thickness in a height direction 31 extending transversely to the width direction 12 and the longitudinal direction 23. The stack 7 and the channels 5 are formed by arranging a different structured region of the same first layer 8 or by arranging the structured second layer 20 on the first layer 8. The other region of the first layer 8 or the second layer 20 is structured such that the superimposed wave troughs 13 and wave crests 14 intersect, so that a contact zone 21 is delimited between the mutually contacting contact surfaces 22 of the wave troughs 13 and wave crests 14 along the extension direction 15. For example, cohesive (soldered) connections 35 are formed at a plurality of contact zones 21, wherein a soldered connection 35 is formed only at a predetermined subset of the contact zones 21.

[0090] The honeycomb body 34 has at least two band-shaped layers 8, 20 with a corrugated structure 9. Fig. 3 shows that, at least partially or at least on a fluid inlet side 2 of the honeycomb body 34, a smooth layer without a corrugated structure 9 is arranged between the band-shaped layers 8, 20 with a corrugated structure 9.

[0091] To form a honeycomb structure 1 through which a fluid 6 can flow from the fluid inlet side 2 to the fluid outlet side 3 of the honeycomb body 34, the layers 8, 20 are arranged with themselves by folding or with at least one other (smooth and / or structured) layer 8, 20 to form a stack 7. In Fig. 3, the honeycomb structure 1 is formed by additionally winding the stack 7.

[0092] The honeycomb body 34 has a round cross-section. The honeycomb body 34 is formed with a tube-like housing 33. When used for exhaust gas aftertreatment, an exhaust gas / fluid 6 regularly enters the honeycomb body 34 via the fluid inlet side 2 or into the honeycomb structure 1 via one of the end faces 10, 11 during operation of the honeycomb body 34 and exits again via the fluid outlet side 3 or the other end face 11, 10. The end faces 10, 11 (of the layers 8, 20 or of the honeycomb structure 1), which are arranged parallel to one another, regularly define the length of the honeycomb structure 1 (or the width of the layers 8, 20) in the direction of a central axis 4 of the honeycomb body 34, which penetrates both end faces 10, 11 and is arranged perpendicularly and centrally to both end faces 10, 11.

[0093] The corrugated structures 9 of the primary structure of the layers 8, 20 are formed over the entire length of the honeycomb body 34 or over the entire width of the layers 8, 20, i.e. between the first end face 10 and the second end face 11. The primary structure of the corrugated structure 9 is formed by elevations (corrugation crests 14) and depressions (corrugation troughs 13). Corrugation crests 14 and corrugation troughs 13 alternate regularly in the longitudinal direction 23 of the layers 8, 20. The corrugated crests 14 and corrugation troughs 13 form a type of sinusoidal corrugation in cross-section. The arrangement of the corrugated structure 9 or the corrugation crests 14 and corrugation troughs 13 in the honeycomb body 34 is such that they run obliquely to the central axis 4. This creates channel sections for a fluid 6 that run obliquely to the central axis 4, rather than parallel to the central axis 4. So if an exhaust gas flow orIf a fluid flow onto an end face 10, 11 perpendicularly, the exhaust gas / fluid 6 is initially divided because it penetrates into the channel openings formed by the wave crests 14 and wave troughs 13 and is then deflected inside the honeycomb body 34 or the honeycomb structure 1. The corrugated structure 9 is such that the wave crests 14 and wave troughs 13 in adjacent regions (viewed in the radial direction 36 relative to the central axis 4) are inclined at different angles or have a different orientation. If, for example, a deflection to the right occurs in one region, it is preferred that a deflection to the left occurs in the region further inside, or vice versa. This alignment or orientation always changes as viewed in the radial direction 36.This means that the wave crests 14 and wave troughs 13 do not lie on top of one another in a linear manner at any point on the honeycomb body 34 of the honeycomb structure 1, but rather cross one another and thus essentially only form point-like support points or contact zones 21 with one another. This results in a structure in which the partial flows of the exhaust gas / fluid 6 are permanently deflected and can flow into adjacent wave crests 14 or wave troughs 13, in particular in a zigzag manner. The wave structure 9 of the layer 8, 20 and the crossing arrangement of the wave structures 9 in the honeycomb body 34 means that the gaps between the contacting layers 8, 20, which are always present in multiple numbers and extend over a great length when the wave troughs 13 and wave crests 14 are aligned straight, are reduced, so that with the same cell density of the honeycomb body 34 orthe honeycomb structure 1 a larger surface area can be provided and unwanted accumulation of washcoat (or other coating) in these interstices can be reduced.

[0094] Fig. 4 shows a first layer 8 in a perspective view. Fig. 5 shows a second layer 20 in a perspective view. Fig. 6 shows a design variant of a layer 8, 20 in a perspective view. Fig. 7 shows the layers 8, 20 according to Figs. 4 to 6 in a view along the direction of travel 16. Fig. 8 shows a section of a honeycomb structure 1 formed by the layers 8, 20 according to Figs. 4 and 5 in a perspective view. Figs. 4 to 8 are described together below. Reference is made to the explanations for Figs. 1 to 3.

[0095] The corrugated structure 9 of the layers 8, 20 each has a secondary structure comprising an inversion of the primary structure, each extending over a maximum of 20% of a distance 17 along the direction 16 between the end faces 10, 11. With the inversion, an intermediate wave crest 18 is formed from a wave trough 13 in the second layer 20 (Fig. 5), and an intermediate wave trough 19 is formed from a wave crest 14 in the first layer 8 (Fig. 4).

[0096] The layer 8, 20 according to Fig. 6 has both types of secondary structures, i.e. intermediate wave crests 18, which are arranged at a distance from the end faces 10, 11, and intermediate wave troughs 19, which extend up to the first end face 10.

[0097] The stack 7 and the channels 5 or the honeycomb structure 1 (Fig. 7) are formed by arranging a structured second layer 20 (Fig. 5) on the first layer 8 (Fig. 4). The second layer 20 is structured such that the superimposed wave troughs 13, wave crests 14, intermediate wave crests 18, and intermediate wave troughs 19 intersect, so that a contact zone 21 is defined between the wave troughs 13 and intermediate wave troughs 19 on the one hand and the wave crests 14 and intermediate wave crests 18 on the other hand along the direction 16.

[0098] The corrugated structure 9 of the layers 8, 20 according to Fig. 4 to 8 has an amplitude 30 (i.e. a maximum extension of the structured layer 8, 20 in the height direction 31).

[0099] With the inversion forming the secondary structure (of a limited area of ​​the primary structure), an intermediate wave crest 18 (second layer 20, see Fig. 5, 6) is formed from a partial area of ​​a wave trough 13 or an intermediate wave trough 19 (first layer 8, see Fig. 4, 6) is formed from a partial area of ​​a wave crest 14.

[0100] Inversion particularly comprises an exclusive deformation of the primary structure (i.e., without a separating cut, not shown here). Thus, the shape of the secondary structure (with an inclined surface) gradually transitions into the shape of the primary structure, particularly along the direction 16 of the channels 5. The gradual transition of the shape of the secondary structure into the shape of the primary structure provides a surface that is inclined relative to a fluid 6 flowing through the honeycomb structure 1 along the direction 16.

[0101] Alternatively, the inversion can be separated from the primary structure by a separating cut, which here runs exclusively transversely to the direction of travel 16 (see Figs. 4 to 8). As a result of the separating cut, which is limited to one channel 5 in each case along the longitudinal direction 23, an additional edge is created within the honeycomb structure 1, which edge can be acted upon by a fluid 6 flowing through the honeycomb structure 1. As a result of the separating cut, the formation of an inclined surface is in particular not required. This can, for example, reduce the flow resistance of the honeycomb structure 1 with respect to a fluid 6 flowing through the honeycomb structure 1 because the channels 5 are not at least partially closed by the inclined surface.

[0102] With each intermediate wave crest 18 or intermediate wave trough 19, an additional contact zone 21 (in addition to the contact zones 21 of the primary structure) can be formed between the wave troughs 13 and intermediate wave troughs 19 on the one hand and the wave crests 14 and intermediate wave crests 18 on the other hand, which is also limited (like the contact zones 21 formed by the primary structure) along the direction of extension 16.

[0103] The secondary structure can be used to specifically provide additional contact zones 21 at which soldered or welded connections 35 can be created.

[0104] In the layer 8, 20 according to Fig. 6, the secondary structures formed as intermediate wave troughs 19 each extend as far as the first end face 10 of the layer 8, 20. Thus, a further contact zone 21 can be formed or provided near the first end face 10 or directly at the end face 10. Thus, in particular by the known joining methods, further (materially bonded) connections 35 can be created in the region of the first end face 10.

[0105] In the layers 8, 20 according to Fig. 4, 5 and 8, the secondary structures are each arranged at a distance from the end faces 10, 11, but close to the first end face. This forms or provides additional contact zones 21 close to the first end face 10. This allows, in particular by the known joining methods, additional (materially bonded) connections 35 to be created in the region of the first end face 10. In a cross-section extending transversely to the direction of travel 16, a contact area 22 of the secondary structure suitable for forming a contact zone 21 with an adjacent layer 8, 20 is larger than a contact area 22 of the primary structure (see in particular Fig. 6).

[0106] The primary structure comprises a sinusoidal corrugation of the layer 8, 20. The, for example, sinusoidal, corrugation has alternating maxima and minima along the longitudinal direction 23, through which the amplitude 30 is formed. The secondary structure, designed as an inversion, forms a flattened maximum or minimum of the corrugation (i.e., not point-shaped in cross-section, but linear along the longitudinal direction 23), so that a contact surface 22 formed by the linear maximum or minimum is larger than the contact surface 22 of the primary structure formed by the point-shaped maximum or minimum.

[0107] In each wave trough 13 and in each wave crest 14 of the layers 8, 20 of Fig. 4 to 8, only one secondary structure is provided.

[0108] The respective secondary structures are arranged at the same position relative to the width direction 12, i.e., for example, in the case of the secondary structure designed as intermediate wave crests 18, at a respective equal distance 32 from the first end face 10 of the first layer 8.

[0109] On the layer 8, 20 according to Fig. 6, a plurality of secondary structures are provided, spaced apart from one another along the direction of travel 16 and arranged in different channels 5. This allows targeted (material-bonded) connections 35 between adjacent layers 8, 20 to be created or provided at specific locations of the honeycomb structure 1.

[0110] At the layer 8, 20 according to Fig. 6, a plurality of alternately arranged intermediate wave crests 18 and wave crests 14 are provided next to one another along a longitudinal direction 23 running transversely to the width direction 12, wherein a plurality of alternately arranged intermediate wave troughs 19 and wave troughs 13 are provided next to one another along the longitudinal direction 23, offset therefrom, along the width direction 12 (and / or direction of extension 16).

[0111] The intermediate wave crests 18 and intermediate wave troughs 19 are provided alternately along the longitudinal direction 23 and are arranged offset or spaced from one another along the width direction 12 or the direction of travel 16.

[0112] In the layers 8, 20, according to Fig. 4, 5 and 8, the secondary structures (intermediate wave crests 18 and intermediate wave troughs 19) of the honeycomb structure 1 are arranged at a small distance 32 from the respective nearest (here the first) end face 10.

[0113] In the layer 8, 20 according to Fig. 7, approximately 50% of the secondary structures (namely only the intermediate wave troughs 19) extend to the first end face 10.

[0114] Fig. 9 shows a side view of the process for producing layer 8 using a rolling device 26. Reference is made to the explanations for Figs. 1 to 8.

[0115] The layer 8 extends between a first end face 10 and a second end face 11 along a width direction 12 and transversely thereto along a longitudinal direction 23 from a first end 24 to a second end 25. The corrugated structure 9 has a plurality of mutually parallel wave troughs 13 and wave crests 14 as a primary structure, each extending at an inclination angle 15 with respect to the width direction 12 of greater than zero angular degrees and at most 15 angular degrees along a direction of extension 16. Furthermore, the corrugated structure 9 has a secondary structure which comprises an inversion of the primary structure. With the inversion, an intermediate wave crest 18 is formed from a wave trough 13 or an intermediate wave crest 19 is formed from a wave crest 14. Step a) of the method comprises providing a rolling device 26 with at least two pairs of rollers 27, 28. Each pair of rollers 27, 28 comprises two rollers that mesh with each other.

[0116] Step b) of the method comprises feeding the still unstructured (i.e. smooth) layer 8 to the rolling device 26 (i.e. from right to left in Fig. 6).

[0117] Step c) comprises the forming of the layer 8 by passing the unstructured layer 8 (supplied according to step b)) through the first pair of rollers 27. In this process, the layer 8 is formed by the meshing surfaces of the rollers and the intermediate shape 29 of the corrugated structure 9 is embossed onto the layer 8.

[0118] Within the scope of step c), for example, only certain parts of the corrugated structure 9 (e.g. only the primary structure or only the secondary structure, and / or parts thereof) and / or only partially formed structures (e.g. with a lower amplitude 30, etc.) can be produced.

[0119] Step d) comprises the forming of the layer 8 having the intermediate shape 29 by passing the layer 8 through the second pair of rollers 28 and forming the corrugated structure 9. The layer 8 is in a predetermined state after step d), ie all primary structures and secondary structures are produced in a fully formed state.

[0120] Several steps c) (i.e., several second roller pairs 28) can be provided, wherein for each subsequent step c), a layer 8 with an already created intermediate shape 29 (created by the previous step c) is further formed. Steps c) then form the intermediate forming stages, and step d) the final forming stage of the successive forming of layer 8.

[0121] Through a multi-stage forming process, the diagonally corrugated layer 8 can be formed step by step until it reaches the desired shape. The individual forming steps can be carried out directly one after the other in a production line as shown (with layer 8 undergoing steps c) and d) at least partially simultaneously, only with different sections of layer 8). With an increasing number of forming steps, the shape of layer 8 is successively increased. In contrast to single-stage corrugation (no step c), only step d)), in each partial step there is again the possibility that the material of layer 8 can "flow" in the strip travel direction (i.e. conveying direction of layer 8, here in the longitudinal direction 23). This allows a higher overall degree of forming of layer 8.

[0122] The intermediate form 29 (after the one step c)) has a largest amplitude 30 of the corrugated structure 9 which is at most 50% of the largest amplitude 30 of the corrugated structure 9 of the structured layer 8 after step d).

[0123] List of reference symbols

[0124] 1 honeycomb structure

[0125] 2 Fluid inlet side

[0126] 3 Fluid outlet side

[0127] 4 central axis

[0128] 5 channel

[0129] 6 Fluid

[0130] 7 stacks

[0131] 8 first layer

[0132] 9 well structure

[0133] 10 first front side

[0134] 11 second front side

[0135] 12 Latitude direction

[0136] 13 wave trough

[0137] 14 wave crest

[0138] 15 tilt angles

[0139] 16 Direction of travel

[0140] 17 Distance

[0141] 18 Intermediate wave crest

[0142] 19 Interwave trough

[0143] 20 second layer

[0144] 21 Contact zone

[0145] 22 Contact surface

[0146] 23 Longitudinal direction

[0147] 24 first end

[0148] 25 second end

[0149] 26 Rolling device

[0150] 27 first pair of rollers

[0151] 28 second pair of rollers

[0152] 29 Intermediate form

[0153] 30 Amplitude 31 Altitude direction

[0154] 32 distance

[0155] 33 housings

[0156] 34 Honeycomb body 35 Connection

[0157] 36 radial direction

Claims

Patent claims 1. A honeycomb structure (1) extending between a fluid inlet side (2) and a fluid outlet side (3) along a central axis (4), wherein channels (5) extend between these sides (2, 3) so that a fluid (6) can flow through the honeycomb structure (1); wherein the honeycomb structure (1) comprises at least one stack (7) formed by at least a first layer (8) having a corrugated structure (9), wherein the first layer (8) extends between a first end face (10) arranged on the fluid inlet side (2) and a second end face (11) arranged on the fluid outlet side (3) along a width direction (12) parallel to the central axis (4);wherein the corrugated structure (9) of the first layer (8) has a plurality of mutually parallel wave troughs (13) and wave crests (14) as a primary structure, each extending at an inclination angle (15) with respect to the width direction (12) of greater than zero angular degrees and at most 15 angular degrees along a direction of extension (16); wherein the corrugated structure (9) has at least one secondary structure which comprises an inversion of the primary structure, each of which extends over at most 20% of a distance (17) present along the direction of extension (16) between the end faces (10, 11), wherein with the inversion an intermediate wave crest (18) is formed from a wave trough (13) or an intermediate wave trough (19) is formed from a wave crest (14); wherein the stack (7) and the channels (5) are formed by arranging another structured region of the same first layer (8) or by arranging a structured second layer (20) on the first layer (8);wherein the other region of the first layer (8) or the second layer (20) is structured such that the superimposed wave troughs; (13), wave crests (14), intermediate wave crests (18) and intermediate wave troughs (19) intersect, so that a contact zone (21) between the wave troughs (13) and intermediate wave troughs (19) on the one hand and the wave crests (14) and intermediate wave crests (18) on the other hand along the direction of travel (16).

2. Honeycomb structure (1) according to claim 1, wherein the at least one secondary structure extends to one of the end faces (10, 11).

3. Honeycomb structure (1) according to one of the preceding claims, wherein in a cross-section extending transversely to the direction of extension (16), a contact surface (22) of the secondary structure suitable for forming the contact zone (21) with an adjacent layer (8, 20) is larger than a contact surface (22) of the primary structure.

4. Honeycomb structure (1) according to one of the preceding claims, wherein a secondary structure is provided in each wave trough (13) or in each wave crest (14) of the first layer (8).

5. Honeycomb structure (1) according to one of the preceding claims, wherein a plurality of secondary structures spaced apart from one another along the direction of extension (16) are provided on the first layer (8).

6. Honeycomb structure (1) according to one of the preceding claims, wherein on the first layer (8) a plurality of alternately arranged intermediate wave crests (18) and wave crests (14) are provided next to one another along a longitudinal direction (23) running transversely to the width direction (12), wherein a plurality of alternately arranged intermediate wave troughs (19) and wave troughs (13) are provided next to one another along the longitudinal direction (23) in a manner offset therefrom along the width direction (12).

7. Honeycomb structure (1) according to claim 6, wherein the intermediate wave crests (18) and intermediate wave troughs (19) are provided alternately along the longitudinal direction (23).

8. Honeycomb structure (1) according to one of the preceding claims 6 and 7, wherein the intermediate wave crests (18) and intermediate wave troughs (19) are arranged spaced apart from one another along the direction of extension (16).

9. A method for producing a structured layer (8, 20) having a corrugated structure (9), wherein the layer (8, 20) extends between a first end face (10) and a second end face (11) along a width direction (12) and transversely thereto along a longitudinal direction (23) from a first end (24) to a second end (25); wherein the corrugated structure (9) has a plurality of mutually parallel wave troughs (13) and wave crests (14) as a primary structure, each of which extends at an inclination angle (15) relative to the width direction (12) of greater than zero angular degrees and at most 15 angular degrees along a direction of extension (16);wherein the corrugated structure (9) has at least one secondary structure which comprises an inversion of the primary structure, which in each case extends over a maximum of 20% of a distance (17) present along the direction of extension (16) between the end faces (10, 11), wherein with the inversion an intermediate wave crest (18) is formed from a wave trough (13) or an intermediate wave trough (19) is formed from a wave crest (14); wherein the method comprises at least the following steps: a) providing a rolling device (26), at least comprising a first pair of rollers (27) and a second pair of rollers (28); b) feeding the still unstructured layer (8, 20) to the rolling device (26); c) forming the layer (8, 20) by passing the unstructured layer (8, 20) through the first pair of rollers (27) and forming an intermediate shape (29) of the corrugated structure (9);d) forming the layer (8, 20) having the intermediate shape (29) by passing the layer (8, 20) through the second pair of rollers (28) and forming the corrugated structure (9); 10. Method according to claim 9, wherein the intermediate form (29) has a largest amplitude (30) of the corrugated structure (9) which is at most 80% of the largest amplitude (30) of the corrugated structure (9) of the structured layer (8, 20).

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