EP1760216A2 - Structured material web made from a web material and method of making - Google Patents

Abstract

The web (2) has a wave shaped and three dimensionally formed structure, which is designed with coils (6, 7) and a roof (8) that is enclosed by the coils. The coils are continuously arranged, and exhibit a curve that opposes the roof curvature. The roof exhibits a spherical shell shape in a middle roof region. The coils are formed based on geometric basic shape from a group consisting of triangle, square, tetragon, rectangle, rhombus or parallelogram, pentagon, hexagon and octagon. A web material is formed in a sandwich design, in which a temporary web is arranged between two outer webs. Independent claims are also included for the following: (1) an article with an application of a structured web (2) a method for manufacturing a structured material web.

Description

The invention relates to a structured material web of a web material, in particular sheet material web, and method for manufacturing.

Background of the invention

For effective lightweight construction, in particular in the automotive, aerospace, interior design, construction and design sectors, or in household appliances and apparatus, as well as in apparatus for molten glass at very high temperatures or for evacuated channels at extremely low temperatures and in the Packaging and lighting industry increasingly complex requirements are placed on the design and the material. Examples include, in particular, low transport and assembly weight, large deformation reserves of the material, low structure-borne noise, high long-term fatigue strength, uniform energy absorption in the event of a crash and, finally, high stability under thermal cycling (thermal expansion inhibition). For economic and ecological reasons, all this should be achieved in a way that conserves resources (materials, coating materials, energy) with the simplest possible machines. These desired features lead to very different and often even contradictory requirements (on the materials used and on the lightweight construction to be stiffened). In this case, the multidimensionally stiffening structures of thin material webs play a very special role, because they give the component a high multidimensional rigidity and further advantageous synergistic properties despite the reduced wall thickness.

Numerous methods are known for providing a thin material web, such as sheet metal or plastic film, with stiffening structures. In order to improve the bending and buckling stiffness of components, mechanically structured materials, such as dimpled sheets, are known. However, these purely mechanically structured materials require high Plastifizierungsreserven of the starting material, since when structuring using mechanical forming and embossing tools a large plasticization of the material occurs. Furthermore, the stiffening known by a bead, which gives the component but only in one direction increased rigidity. Perpendicular to the component remains bending and pushing soft.

From the document EP 0 693 008 B1 Beulstrukturierte material webs are known, which are made on the basis of a self-organized structuring process out of a curved shape out. Thus, thin-walled sheets and foils can be structured in a materially and multi-dimensionally gentle manner in comparison to purely mechanical embossing methods (cf. DE 198 56 236 A1 ). The beulstrukturierten material webs are then converted in a special straightening process, in which the structures are completely preserved, in the planar shape. The multi-dimensional buckling structures produced in this way are also called "vault structures". They have a regular structuring with wrinkles and traps enclosed between the folds.

In the known buckling / vault structuring method, in the curved and internally partially supported material web at a low external pressure load initially, ie at the beginning in the elastic material behavior of the material web, sinusoidally revolving structural waves, which have only a very small amplitude. If the external pressure load against the curved material web is then increased, an unstable state is created, which triggers a dynamic breakdown (spontaneous denting) in the elastic-plastic material behavior of the material web. This complex process can be described by the non-linear laws of mechanics (nonlinear geometrical deformation of shells), thermodynamics and material (non-linear, elastic-plastic flow curve), far away from the equilibrium state. These, self-organizing, Beulstrukturen can the so-called "dissipative structures" (see. I. Prigogine et al .: "Dialogue with Nature", Piper Series, SP1181; P. 21, p. 152 ; F. Mirtsch et al.: "Corrugated Sheet Metal on the Basis of Self-organization", First International Industrial Convenience Bionic 2004, Hannover Messe, Germany in: Fortschritt - Berichte VDI Series 15, p. 299 - 313 ) be assigned.

In this case, it should be noted in the case of Beulstrukturierens that the kinetic energy in the dynamic breakdown of the curved material web in their countercurve / bulge largely in plasticizing energy (heat) of the forming Bealtenalten is converted. This is due in particular to the fact that the resounding buckle shell acts as a kind of "lever" on the resulting fold and thereby forms a Beulfalte with very small radius with significant plasticization of the material. Through this dynamic breakdown of the spontaneous buckling of the originally sinusoidal rotating wave with very small amplitudes creates a kind of "garland wave", which is composed of juxtaposed cosinus half-waves corresponding to juxtaposed buckets. In each case, an upper half-wave of the original sine wave has contracted after the dynamic breakdown, so that each results in a single Beulfalte. In this way, the wavelength of the resulting lower cosine half wave (Beulmulde) becomes larger, and thus receives twice the length of the previous lower sine wave before the breakdown.

However, the known bulge / vault structured material webs have disadvantages if the above-mentioned complex, often contradictory requirements are to be met. The existing disadvantages will be explained in more detail below. The folds of the bulge / vault structured materials have small bending radii, as they occur when a material is folded. There, the material of the structured material web is much more reshaped, and therefore the material is comparatively highly plasticized in the area of the folds. Because the folds are always narrow and therefore occupy only a very small area and yet contribute significantly to the dimensional stability of the structured material, the material in the region of the folds in the load case of the structured component is subjected to relatively high stress. In this way, small visible or even invisible to the naked eye cracks, such as microcracks occur in the folds, in which dirt or bacteria can accumulate.

The traps enclosed by the folds occupy by far the largest part of the surface of the material web and are only slightly deformed in the load case, because the depression as a three-dimensional shell is very particularly dimensionally stable. This relationship can be understood in a somewhat simplified way so that the narrow folds are regarded as flexible "hinges" and the trough as very rigid elements. It follows immediately that the folds the Danger of a "predetermined breaking point" with high static load, with fatigue load, with thermal cycling and in the event of a crash.

Another disadvantage of the known bulge / vault structured material webs is that they behave very torsionally soft and at the same time unstable especially at low Beulfalten. They "flip" easily with small torsional loads back and forth.

Another disadvantage is that the wells, which are also referred to as bulges, especially in large structural wells, have no uniform and no spherical surface-like curvature. Instead, for example, the wells of the known bulge / bulge structures in the adjacent region of their folds have very irregular curvatures, because the geometric transition from the narrow folds of a hexagon to the enclosed well causes unavoidable, disturbing transitions. This leads in particular to larger hexagonal structures to disturbing geometric inhomogeneities and to a flattening of the curvature in the middle of the trough. This is undesirable, particularly in lighting technology, because this means that it is not possible to realize a uniform, namely direction-independent, glare-free light reflection on the reflectors of luminaires.

Furthermore, a major disadvantage of the known buckling / bulge structures is that, despite the large plasticizing reserves in the region of their wells, a large structural depth of the bulge / bulge structure can not be achieved for optimum shape rigidity, without risking the material in the area the considerably plasticized fold breaks during the structuring itself or during the subsequent component loading. This means that the large plasticizing reserves that were still in the hollows can not yet be used to produce large structural depths and high component rigidities. This is not possible with the help of the known support structures, which has an involute on its supporting flanks (cf. EP 0 888 208 ), because here too structural folds arise that still have disturbing geometric transitions from the narrow folds to the trapped hollows. Until now, it has not been possible to state concretely how such an involute should be optimally geometrically designed.

In the known bulge / vault structured material, a further disadvantage is that the beulstrukturierte material web must be directed after structuring from its curved shape in the planar shape and in particular the wrinkles in the direction of the web, which were disproportionately plasticized during Beulstrukturieren , be further plasticized by judging. In particular, the following causes exist for this purpose. Since during buckling the folds of the curved material web are arranged on the outside (i.e., larger radius) and the troughs on the inside (i.e., smaller radius), the folds in the direction of travel of the material web are compressed during straightening and the troughs are stretched. However, since the wrinkles occupy only a very small area of the beulstrukturierten material web in comparison to the trough, the wrinkles are strained in disproportionate straightening and thereby highly plasticized. Because of the elongation of the troughs, the folds are stretched transversely to the direction of travel of the material web at the same time and thereby drawn slightly flatter. In summary, by straightening the bulge / vault-structured material web, the pleats are compressed in the direction of the material web, whereby the pleat height is increased, while the pleats are stretched transversely to the material web, so that the pleat height is reduced. In the known bulge / vault structured material webs, the pleat height in the direction of the material web is approximately twice as great as the pleat height transversely to the direction of travel of the material web. This results in a strong unwanted anisotropy in the bending, shear and torsional stiffness of the directed structured material web.

Finally, there is a significant disadvantage in that the known bulge / vault structured material webs can not or only very difficult bend or edge, when the bending radius is considerably smaller than the radius of the support roller used for producing the bulge / bulge structures. Practice has shown that the known method for the secondary deformation bulge / wölbstrukturierter material webs (see, in particular DE 198 47 902 B4 ) quickly reaches its limits when the folds and troughs have to be bent much closer together in order to achieve a small radius of curvature of the material web. The troughs and possibly also the folds buckle during tight bending, because they are unstable by high voltage spikes in the material. The disadvantage here is that then for the entire material web to select considerably smaller structure sizes and depths to the kicking to avoid bending, which in turn give the flat or slightly curved wall sections of the workpiece only a low stiffness.

Summary of the invention

The object of the invention is to provide an improved structured material web and a method for producing in which the disadvantages of the prior art are overcome, in particular the disadvantages due to the fold structure. Furthermore, a material-friendly straightening of the structured material web should be made possible. Furthermore, the improved structured material web should allow tight bending.

This object is achieved by a structured material web according to independent claim 1 and a method for producing a structured material web according to independent claim 20. Advantageous embodiments of the invention are the subject of dependent subclaims.

According to one aspect of the invention, a structured material web of a web material, in particular sheet material web, having a wavy and three-dimensional structure is formed, which is formed with beads and of the beads enclosed domes, wherein the beads are made continuous and have a curvature, the opposite to the curvature of the calotte is.

According to a further aspect of the invention, a method for producing a structured material web, in particular a structured sheet material web, is provided, in which a material web of a web material is provided by means of beads and beads enclosed by the beads with a wavy and three-dimensional structuring, wherein the beads be formed contiguous and with a curvature which is opposite to the curvature of the calotte.

It has surprisingly been found that, instead of the known narrow folds which are formed in the prior art by means of a dynamic buckling process of a curved material web, multi-dimensional wavy structures are produced in a material-saving manner when forming beads which include calottes. Because the calotte has an opposite curvature as the beads, a multidimensional wave train results in different directions in the so-structured material web. Therefore, this type of structuring is called multi-dimensional wavy structuring.

The beads in the structured material web are comparatively less plasticized, substantially free of cracks and can absorb significantly greater loads and deformations than the known narrow Beulfalten. In contrast to the wrinkles in the structuring known from the prior art, the beads behave much less sensitive and more stable against thermal expansion obstacles in thermal cycling and vibration loads. Finally, due to the greater elastic deformation capacity of the bead relative to the known fold of the failure case under external load, especially at impact load shifted considerably further towards greater loads.

The beads differ from the known beul- / wölbstrukturierten wrinkles in terms of their radius' in relation to the thickness of the web. These relationships are influenced in particular by the nature of the material used for the material web, the shape of the supporting elements used in the production in the structuring process and the thickness and the Shore hardness of elastic interlayer for three-dimensional wavy structuring. These relationships arise from the manufacturing process, which is explained in more detail below. The following two statements quantify these relations by way of example. In a first case, a sheet of aluminum sheet of thickness 0.3mm is provided with a crest-like structure, ie hexagonal structures with slightly curved beads / calottes, the key width 33mm. The ratio of bending / radius of curvature of the bead to the material thickness (of the three-dimensional wave-structured material web) is about 13. The ratio of bending / bending radius of the known in the prior art fold to the material thickness (buckling / vault structure), however, is about 5. In in a second case is stainless steel sheet (1.4301) of thickness 0.25mm provided with a crest-shaped structure of key width 33mm. In the case of the three-dimensionally wave-shaped structured material web, the ratio of the bending radius of the bead to the material thickness is about 16. The ratio of the bending radius of the known fold to the material thickness is 7. In both cases, an elastic intermediate layer of thickness 4 mm and Shore hardness was used to produce the bead 60 used. In the case of the three-dimensionally wave-shaped structured material web, the ratio of the value for the bending / bending radius in the region of the calottes to the value of the material thickness is therefore preferably at least about 8, preferably at least about 10 and more preferably at least about 15.

At the same time this reduces the likelihood of cracking due to the gentle curves of the beads. The curves result from the material thickness and the material properties (yield strength, ductility) of the starting material used. This results in hygienic structured walls and apparatus in food technology, which are also easier to clean because of the gentler curves.

A preferred embodiment of the invention provides that the calottes in a central Kalottenbereich have a shape which is at least approximated to a spherical shell shape.

In an advantageous embodiment of the invention can be provided that the beads are formed contiguously according to one or more basic geometrical shapes of the following group of geometric shapes: triangle, square, in particular square, rectangle, rhombus or parallelogram, pentagon, hexagon and Octagon.

In an expedient development of the invention, it is provided that the beads are formed according to a uniform geometric basic shape.

In a preferred embodiment of the invention can be provided that the beads and / or the calotte are each formed with a substantially uniform bead / dome height. In the known bulge / vault structured folds the heights are very different. The pleats in the production direction are almost twice as high as the folds across the production direction, because when judging in the planar shape, the first wrinkles are compressed and thus increased, and the second wrinkles are stretched and thereby flattened. This results in an undesirable anisotropic bending stiffness of the structured material webs, which is now prevented in the invention.

An advantageous embodiment of the invention can provide that the web material is selected from a material from the following group of materials: metal such as aluminum, steel, stainless steel, magnesium, titanium, platinum alloys, plastic, fibrous materials, in particular paper and cardboard, fiber fabrics and mesh fabrics , Sheet metal materials are preferably used. Preferably, it is provided in a further development of the invention that the web material is formed in a sandwich construction, in which at least one intermediate web is arranged between two outer webs.

A preferred embodiment of the invention provides that for at least a portion of the calotte a Kalottenoberfläche is broadly diffuse reflective, wherein at least the part of the calotte is formed with the broadly diffusely reflecting Kalottenoberfläche as deep calotte. In an advantageous embodiment of the invention can be provided that a Kalottenoberfläche is directionally reflective for at least a portion of the calotte, wherein at least the part of the calotte is formed with the directionally reflective Kalottenoberfläche as a flat dome. Preferably, the structured material webs on uniform, large and deep and approximately spherical domes, at the convex side of the light almost uniformly, d. H. essentially independent of the angle of incidence, and at the same time broadly diffused. Thus, in particular, the principle desired by the lighting industry of the so-called light point decomposition can be realized for glare-free or at least very low-glare light reflection even for the broad light scattering of large luminaires and indirect ceiling spotlights. Even with a reflection of the light on the concave side an improvement over the known bulge / vault structured material web is achieved.

In an expedient development of the invention it is provided that the sheet material is anodized aluminum sheet.

In a preferred embodiment of the invention it can be provided that the undulating and three-dimensional structuring is formed as a self-organizing structuring.

A further advantageous embodiment of the invention may provide a curved portion, which is optionally designed as a bent portion and in which a curvature is formed with a narrow radius of curvature, wherein the beads and dome in the region of curvature are executed kink free. The bent version is made by bending. In one embodiment, it is preferably provided that the curvature is formed in the direction of a curvature on an outwardly directed side of the calotte. While the known folds and their trapped hollows of buckling / buckling structures behave rigidly and buckle in bending or entanglement, surprisingly behave the beads quite different due to their gentle curves and their enclosed calottes. When tightly bending the three-dimensionally wave-shaped structured material web, the beads can distribute bending, pushing and torsion-like quasi the high local bending loads on adjacent areas, by themselves, d. H. "entangle" without mechanical molds and thus "dodge" the danger of high voltages and instability.

When bending in the running direction of the material web, the zigzag beads of the material web are steplessly adjusted in their running direction in a hexagonal structure, so that they gradually align more and more in the direction transverse to the running direction of the material web, so to speak, "interlace" and thereby have a curved shape accept. As a result, the beads are shortened transversely to the direction of the web until they disappear completely. Thus, with increasing bending, ie decreasing radius of curvature, the material web from the zig-zag shape of the beads in the running direction of the material web finally becomes a serpentine bead which runs through transversely to the running direction of the material web. The special feature of the three-dimensional wave-like structure is therefore that it contains these "entanglements", namely Forming without mechanical tools, in the first place. Behind this "entanglement" is a general principle: Although the beads and the calottes represent a resistance to deformation due to their area moment of inertia ("third dimension"). However, they can avoid the high stresses and instabilities during forming, for example bending if the beads were already aligned somewhat obliquely to the direction of the material web before bending and then the beads during bending more and more oblique, ie transverse to the direction of the web, set. In summary, the structured material deforms by this type of entanglement by itself so that it avoids an external load without buckling. Here, the geometric and material-technical non-linear laws play a crucial role. Similar phenomena can also be found in the living and inanimate nature.

The above-described properties of the three-dimensionally wave-shaped structured material web enable the advantageous use of the material web for articles in different fields of application. These include non-circular tubes, for example, have an oval or elliptical cross-section, or curved channels, which consist of curved and flat circumferential wall sections that can be equipped with larger and deeper structures than when using the known buckling / Völbstrukturen the case is. The maximum structure size and thus the rigidity is limited in the known buckling / arch structures downwards by the small radius of curvature of the oval or the ellipse. Larger bulge / bulge structures with greater rigidity can not be placed on the oval or elliptical section with the small radius of curvature, because they would buckle and thus lose their high rigidity. In this way, since the regions of oval or ellipse having the large radius of curvature for high rigidity can not be provided with the mating larger and deeper structures, high overall rigidity of the oval shaped tube has not been attained so far. With the help of the new three-dimensional wave-shaped structures, the regions with the large radius of curvature receive large and stiff structures, for example, corresponding to the radius of curvature of the self-organizing structuring process. These big and stiff three-dimensional wavy Structures can also be used on the oval or elliptical section with the small radius of curvature without loss of stiffness due to buckling.

Oval or elliptical components with high overall stiffness are preferably used in the two following applications, with additional synergistic properties occur. First of all, glass production is to be mentioned here by way of example, for example as thin-walled oval or elliptical outgassing tubes made of platinum alloys, so-called "refining chambers". Components for the molten glass, in particular for refining chambers, are subject to complex requirements. These include the compensation of thermal expansion disability, a uniform temperature distribution and the most uniform residence time of the molten glass in the components and the fastest possible escape of the gases from the molten glass. These requirements are explained in more detail below.

As a result of the heating, the tubes, channels, crucibles and agitators made of platinum alloys expand considerably from room temperature to the melting temperature of the glass (about 1600 ° C.) (magnitude above 1%). This results in high stresses in the thin platinum walls, because these are usually fixed by surrounding ceramic brick walls and axial flanges / fasteners and so their thermal expansion is hindered. According to the prior art in the document DE 100 51 946 A1 Corrugated pipe walls are known which allow compensation of the thermal expansion impairment. While the unidirectionally corrugated known tube walls permit only axial compensation and can buckle in the event of radial expansion interference, the multi-dimensional, wave-shaped structured walls allow thermal expansion compensation to be compensated in both the axial and the radial (circumferential) direction. The three-dimensionally wave-shaped structured tube walls are superior to the known bulge / vault-structured tube walls, because they have opposite the narrow folds (in the bulge / bulge structures) beads, which are wide and gently rounded and occurring in the thermal expansion disability local stress peaks better and more uniform distribute adjacent areas of the pipe wall.

The tube walls of the three-dimensional wave-shaped structured material webs are the known pipe walls (see. DE 100 51 946 A1 ) in terms of a uniform temperature distribution in the electrical heating of the pipe walls and a homogeneous residence time of the molten glass in the tubes and channels superior, because in the known pipes, the flow is alternately constricted and then widened again. This results in the low flow velocities of the molten glass, ie very small Reynolds numbers in the laminar range, to comparatively large "dead water areas". This is not the case with the three-dimensional wave-shaped structured pipe walls because their structures are arranged exactly offset in the flow direction and therefore the average hydraulic flow cross section of the pipe is constant everywhere.

According to the state of the art in DE 102 49 682 A1 have known oval or elliptical refining compared to the circular refining chambers on the advantage that they have a significantly larger phase interface liquid / gaseous (aligned with their horizontal cross-sectional area in the direction of the long axis of the oval / ellipse) and thus additionally a much smaller vertical distance from the lower tube wall to the horizontal phase interface liquid / gaseous. These two effects cause the degassing process of the molten glass in oval / elliptical tubes / channels to proceed faster than in circular tubes / channels. With the help of preferably oval or elliptical shaped pipe walls, which are equipped with three-dimensional wave-shaped structures, the accelerated degassing can also be realized and in addition the aforementioned disadvantages of the known pipe walls such as high local stresses caused by thermal expansion obstructions and occurring dead water areas can be avoided. The three-dimensional wavy structured walls of the expensive platinum alloys also have the significant economic advantage that, for example, with the same (usable) length of the refining chamber quite considerably less precious metal (platinum, rhodium or the like) is needed because the known tubes (see. DE 100 51 946 A1 ) when structuring compared to the originally smooth tubes greatly shorten on the order of at least 10%, while the three-dimensional wave-shaped tubes are structuring only very little (order of magnitude 1%) are gathered.

Another example of use for oval-shaped or elliptical thin-walled tubes with a three-dimensional wavy structured wall relates to evacuated synchrotron tubes / channels, for example for brain tumor control using heavy ions. Prior to their medical use, the fast heavy ions are preferably "parked" in oval or elliptical, thin, for example, stainless steel tubes of a storage ring. In order to keep the electrical energy for the circular guide (storage ring) of the heavy ions by means of magnets low, the latter are operated near the absolute zero at about 4 K in superconductivity. In order to keep a heating of the tubes as small as possible because of unavoidable electromagnetic eddy current losses, which are preferably oval or elliptical tubes must be carried out of the storage ring as thin as possible while the external atmospheric pressure (in the tubes is high vacuum) withstand (see. " Design and study of a superferric model dipole and quadrupole magnets for the GSI fast-pulsed synchrotron SIS 100 ", A. Kovalenco et al., Proceedings of EPAC 2004, Lucerne, Switzerland, pages 1735-1737 ). At the same time, the thin-walled pipes must withstand the thermal stresses during start-up, in particular a temperature reduction of about 290 ° C, and shutdown of the plant, namely a temperature increase of about 290 ° C, certainly. This results from the embedding of the thin-walled tubes and possibly by, for example, welded cooling tubes unavoidable thermal expansion impediments. With the help of the three-dimensional wave-shaped, thin-walled tubes / channels, these complex requirements, such as bending into the oval-shaped or elliptical tube shape, the high overall stiffness by comparatively large and deep structures and further low stress compensation (thermal expansion) even at extreme thermal cycling fulfill.

Similar applications arise in space travel, for example, when a space probe from the sun enters the Earth's shadow.

In the method, an advantageous embodiment of the invention provide that the beads and the dome are formed by the material web curved and then by an external pressurization on its inner side first against an elastic intermediate layer, which is arranged on rigid support elements, and then against the rigid support elements is pressed. In an expedient development of the invention it is provided that an intermediate layer of a material or a combination of materials of the following group of materials is used as the elastic intermediate layer: elastomer, flexible material and fibrous material.

It has surprisingly been found that the beads form with their gentle transition to the calotte particularly gentle on the material with the help of a quasi-free deformation of the web that between a curved material web and the support elements in addition an elastic intermediate layer is arranged and then this material web from the outside is pressurized. This elastic intermediate layer, which is preferably considerably thicker than the material web thickness, preferably about a factor of 4 to 10, and has a Shore hardness of about 50 to 70, fulfills a different purpose than is the case with intermediate layers in the prior art. The material is deformed more uniformly and gently, whereby preferably deeper structures in the material web can be produced without the material breaking during the Shore hardness deformation.

The rigid support elements are preferably made of rigid materials. But they can also consist of elastic materials.

Experiments have shown that the disadvantages of the spontaneous, dynamic breakdown can be eliminated with the aid of the additional, comparatively thick, elastic intermediate layer which is arranged between the inside of the curved material web and the support elements. Due to the elastic intermediate layer, the dynamic breakdown during structuring of the material web is drastically reduced. Here, the elastic intermediate layer deforms in the region of the support elements almost by itself in such a way that the material of the intermediate layer by the quasi free-deforming and pressing material web in each case in the region of the support elements is so pressed / squeezed that the immediately adjacent to the support element depressed material of the intermediate layer with this support element quasi a new, "common" and therefore considerably wider support element than before. This "common" support element has adapted itself virtually to the freely deforming web individually. The width of the "common" support element can be variably adjusted by means of the wall thickness and the hardness of the material of the intermediate layer in connection with the web width and rounding of the rigid support elements.

The elastic intermediate layer leads to the further important advantage that the multi-dimensional wavy structured material web has only a very small curvature in the direction of the material web immediately after structuring and therefore the subsequent straightening effort in the planar shape is low. The reason for this is that the material web is no longer bent so much around the support element core by a preferably thicker elastic intermediate layer and is therefore rather in a slightly curved shape during structuring and therefore the subsequent straightening process is much easier. This also improves the flatness of the material web.

There is another advantage. Since due to the elastic intermediate layer of the radius of curvature of the three-dimensionally wave-structured material web is greater than the radius of the support roller element, the beads are less strongly compressed in the direction of the web by the subsequent straightening in the planar shape and therefore only slightly increased. In the known bulge / vault structured material web, however, the wrinkles are greatly compressed in the direction of the web by straightening and thereby greatly stretched the troughs and wrinkles transverse to the direction of travel of the web and thus pulled much flatter. Therefore, three-dimensionally wavy structured material webs can be easier to direct in the planar shape and advantageously obtained comparatively in all directions about the same or only slightly different bead heights.

Exemplary experimental investigations show the difference between a three-dimensional wave-structured material web and a known bulge / vault structured Material web using the example of a steel sheet (DC 06) of thickness 0.8 mm and a hexagonal structure with the key widths of 50 mm. In the three-dimensional wave-shaped structures, which are produced with a 6 mm thick elastomeric interlayer of Shore hardness 60, results in a ratio of 1.2 compared to the ratio of 1.7 in the known between the bead heights in and across the direction of travel of the web bulge / vault structured structures. Another example shows the results for a 0.5 mm thick stainless steel sheet with the hexagonal wrench size 50 mm and when using the same elastomeric intermediate layer (6 mm, Shore hardness 60): The result is between the bead heights in and across the direction of travel of the material web Ratio of about 2.0 compared to the ratio of about 3.0 in the known bulge / vault structured structures. A third example with aluminum sheet (6061 T6) of thickness 0.6 mm and hexagonal wrench size 33 mm and using the same elastomeric intermediate layer (6 mm, Shore hardness 60) gives the following results: It results between the bead heights in and across the direction of the web Ratio of about 1.3 compared to the ratio of about 1.9 in the known bulge or vault structured structures. As a result of the homogeneous heights of the beads, more uniform, ie improved, direction-independent, bending, shear and torsional stiffnesses of the three-dimensionally wave-shaped structured material web compared to the known bulge / vault-structured material web are obtained. The advantages of more uniform bead heights are the resulting more uniform shape stiffnesses in different wall directions than can be achieved with the use of the known buckling or buckling structure.

Since the method avoids a strong curvature during patterning, even with higher-strength materials, such as high-strength sheet metal and even fiber-reinforced plastics, improved directionality of the three-dimensionally wave-shaped structured materials results.

An advantage of an elastomeric intermediate layer is in particular that the elastomer of the intermediate layer during pressing of the material web "flows" not only perpendicular but also parallel to the material web and thereby shear forces between the elastomer and the wall surface of the material web arise. These additional shear forces work together with the "common" broad support element that forms a broad and at the same time evenly curved bead (in contrast to the narrow Beulfalte the buckling / Völbstrukturieren) in the material web.

The beads also facilitate the straightening of the three-dimensional wave-shaped structured material web in the planar shape. This can be explained by comparing the behavior of the folds of the known bulge / bulge structures with the bulges of the three-dimensional undulating structures. Both structures have in common that they are formed by hexagonal support elements from the curved smooth starting material web out. The hexagonal structures form on a cylinder circumference. In each case, three folds / bulges converge at the corner points of the hexagon to form a star point and, as a result of the cylindrical material web, each result in a small spatial triangular pyramid. As long as this triangle pyramid has a spatial extent (large area moment of inertia), it behaves dimensionally stable and stable to external loads, because the external forces acting on the pyramid are low and low-voltage derived and distributed. The folds / bulges behave more or less like rods and the trapped depression sections almost like small shear fields. When directing the curved structured material web in the planar shape of the Pyramidenspitze is disproportionately (geometrically non-linear) by compressing the folds / beads loaded on pressure until a plastic deformation of the material occurs and the risk of unstable "flip" (dynamic breakdown) from the convex to the concave curvature of the pyramid and thus the entire material web occurs. In the known folds with their narrow bending radii of the bulge / vault-structured material web, this undesired folding-over process actually occurs and has been repeatedly observed on the basis of optically visible very irregular small undulations in the region of the star points. In the three-dimensional wave-shaped structured material webs, this unwanted "folding over" does not occur or only very weakly, because the beads are much wider than the narrow folds. In the case of the wide beads, the high tensions in the pyramid tips are derived more uniformly in accordance with the star points of three converging beads than in the narrow folds of the known bulge / crown structures.

In a preferred development of the invention it can be provided that a pressure component made of an elastomer or an active medium is used for the external pressurization.

In a further advantageous embodiment of the invention can be provided that instead of a separate elastic intermediate layer of the elastomeric material is fixed directly on the core on which the rigid support members are mounted. As a result, the entrained elastic intermediate layer can be omitted.

An advantageous embodiment of the invention can provide that the rigid support elements are arranged on a core or in a tool, which / has a contour adapted to a desired bead structure of the beads. Thus, in one embodiment, the additional elastic intermediate layer can be dispensed with. The contour of the rigid support elements is already formed according to the "common" support elements described above. The "common" support element results, as described above, from the originally narrow support element and the self-adjusting contour of the elastomer of the additional intermediate layer in the three-dimensional wave-like structuring. Preferably, the diameter of the rigid support member roll may be selected to be similar to the radius of curvature of the web formed by the self-leveling elastic structuring process (which is greater than the radius of curvature of the original support roll). Based on the above-described experimental comparison on the basis of material DC 06, a wall thickness of 0.8 mm and a wrench size 50 mm results in a ratio of the diameter of the new support element roller without elastomeric intermediate layer to the diameter of the support element roller with elastomeric intermediate layer of about 1.5.

A further expedient embodiment of the method for producing three-dimensionally wave-shaped structured material webs with the aid of an elastic intermediate layer is that a smaller number of support elements is arranged on the uniform support element roll circumference, so that larger structures are formed. As a result of the elastic liner The structured material web leaves the structure roller with a curvature corresponding to that of a correspondingly larger structuring roller without the use of the elastic intermediate layer. The advantage here is that the three-dimensional wave-shaped structures can be equipped in this way with deeper troughs. The structures are in this case more pronounced because a smaller number of structures on the same cylinder circumference has a larger angle section of a structure on the circumference of the cylinder result.

In a further development of the invention, it is preferably provided that the undulating and three-dimensional structuring is formed with a low curvature ("coil set") . In contrast, the curvature of the known bulge / vault structured material web is very large, because the structured material web closely adheres to the support element roll during structuring.

A further embodiment of the invention provides that the three-dimensionally wave-shaped structured material webs is produced by means of a complete mechanical forming die (instead of a support element roll) into which the contours of an already three-dimensional wave-shaped structured material web are integrated by means of a mechanical production. In this way can be dispensed with the additional elastic intermediate layer. Thus, the web to be structured is pressed with the aid of an active medium, for example an elastic or pneumatic / hydraulic pad or an elastic pressure roller, directly against the mechanical forming die and in this case three-dimensionally wave-shaped. The advantage is that no wear of an elastic intermediate layer occurs and no additional device for transporting and guiding the elastic intermediate layer is needed. Instead of the active medium, it is also possible to use a mechanical stamp, into which the corresponding contours are likewise incorporated, which are modeled on the three-dimensionally wavy structured material web.

A material web formed and produced in the manner described above can be used according to one of the illustrated embodiments, optionally after suitable further processing, in various applications by utilizing the described advantageous properties be, in particular as a structured material web for parts in vehicles, for example, a stiffening and impact energy absorbing reinforcing shell for a hood, a tailgate, a side part, a partition, a bottom part. Depending on the field of application, the material is suitably used: steel, aluminum, titanium, magnesium or alloys thereof.

In contrast to the fold in the known from the prior art structuring, the bead behaves much less sensitive to thermal expansion obstacles in thermal cycling and vibration loads. Finally, due to the greater deformability of the bead relative to the known fold of the failure case under external load, especially at impact load shifted considerably further to greater loads. Therefore, three-dimensionally stiffened thin walls or foils or sandwiches are particularly well in the field of automotive engineering, such as for walls, roofs and body panels, aerospace for panels, awnings, enclosures, encapsulation, insulation and apparatus walls and in the cryotechnology (at low temperatures) and in thermal engineering (at high temperatures) suitable. In all of these exemplified applications, the synergistic benefits of three-dimensional wavy structured materials are demonstrated in terms of high stiffness, low weight, and safety at different dynamic loads.

If two or more three-dimensionally wavy structured material webs are joined together by thermal joining, mechanical joining and / or gluing when superimposing the uniformly spherical domes of the three-dimensionally wave-structured material web, further advantages of the simple construction result. These include, for example, a flow channel with an advantageous turbulence or deflection of a flow boundary layer for improved heat and mass transfer. This also includes a sandwich construction for a defined heat conduction or thermal insulation of thin, punctiform connected structured and dimensionally stable thin walls or foils, which can be used, for example, in space technology.

When used as an inner reinforcing shell, which is connected to an outer hood shell to protect the pedestrian during head impact, the wave-shaped and three-dimensionally structured material web has the significant advantage that even very deep structures can be produced, which for a uniform and at the same time impact energy absorbing effect in body-compatible head impact are better suited than the known hood shells (reinforcing shells) with the buckling / bulge structures, which in the documents DE 102 59591 A1 and in DE 10 2004 044 550 A1 are disclosed. These known hood shells still have the disadvantages that the maximum achievable structure depths are still unsatisfactory, and further the fatigue strength is still low in the dynamic load occurring due to the tight fold radii. The significant improvement with the help of the three-dimensional wave-shaped material web for the hood shell. can be explained as follows: The second moment of inertia in connection with the outer bonnet shell and thus the impact energy absorption per deformation path becomes larger. In the case of head impact or in the event of a crash, the area of the beads deforms considerably more than the area of the cap, which is a consequence of very great stiffness of the calottes. In the deformation in the bead significantly lower local material stresses arise as in the folds of the known buckling / vault structure, since the folds have a very narrow curvature and occupy a very small area proportion of the structured material web. These significantly lower material tensions in the beads have a very favorable effect on the fatigue strength (crash performance and fatigue strength / Wöhler curve) not only during deformation during impact but also during long-term, dynamic driving.

When using the structured material web for cans, in particular cans, the structuring with beads and calottes has the advantage that larger structure depths can be applied. Another advantage results from the fact that in comparison to the known tight fold of the bulge / bulge structures, the wider beads considerably less sensitive to local buckling in lateral striking the cans against each other (during their production or later during transport) or when gripping the filled Canned by the consumer behavior.

When using the three-dimensional wave-shaped structured material web in the lighting industry, especially for reflectors with diffuse, low-glare light scattering, the uniform spherical domes provide the advantage that even with large structures an exact point-like reflection is achieved according to the principle of light point separation.

Description of preferred embodiments of the invention

Fig. 1

schematisch eine Vorrichtung zum Herstellen einer herkömmlichen beul- / wölbstrukturierten Materialbahn nach dem Stand der Technik;

Fig. 2

schematisch eine Vorrichtung zum Herstellen einer wellenförmigen und dreidimensional gebildeten Strukturierung einer Materialbahn mit Hilfe einer transportierten elastischen Zwischenlage nach der Erfindung;

Fig. 3

im oberen Bild den Querschnitt durch einen dünnwandigen runden Zylinder (gestrichelter Kreis) und eine sinusförmige, elastische Welle (durchgezogene Linie), die sich bei geringer äußerer, allseitiger hydraulischer Druckbelastung (vor dem dynamischen Durchschlag) einstellt, und im unteren Bild eine "girlandenförmige" Welle nach dem dynamischen Durchschlag (bei erhöhter äußerer, allseitiger hydraulischer Druckbelastung);

Fig. 4

im oberen Bild den Querschnitt einer dreidimensional wellenförmig strukturierten Materialbahn im Schnitt entlang einer Linie A - A und im Schnitt entlang einer Linie B-B und im unteren Bild die entsprechende Draufsicht mit der Positionierung dieser beiden Schnitte;

Fig. 5

schematisch eine Vorrichtung zum Herstellen einer dreidimensional wellenförmig strukturierten Materialbahn mit Hilfe eines Kerns mit breiten Stützelementen (oberer Teil) und eine Draufsicht auf einen Ausschnitt der dreidimensional wellenförmig strukturierten Materialbahn (unterer Teil);

Fig. 6

den Querschnitt durch eine dreidimensional wellenförmig strukturierte Materialbahn mit einfallenden und reflektierten Lichtstrahlen;

Fig. 7

einen Abschnitt einer Motorhaube im Querschnitt und eine Verstärkungsschale in Aufsicht;

Fig. 8

im Querschnitt einen Abschnitt einer Motorhaube für den Fußgängerschutz mit einer inneren Verstärkungsschale aus einer dreidimensional wellenförmig strukturierten Materialbahn;

Fig. 9

einen Abschnitt eines dünnwandigen Rohres im Querschnitt aus einem dreidimensionalen wellenförmig strukturierten dünnwandigen Material;

Fig. 10

im oberen Bild den Querschnitt durch eine strukturierte, dünne und zugleich formsteife Wand aus einer dreidimensional wellenförmig strukturierten Materialbahn und im unteren Bild den Querschnitt durch ein Sandwich aus einem oberen und unteren Gurt aus einer dreidimensional wellenförmig strukturierten Materialbahn;

Fig. 11

eine schematische Darstellung zur Erläuterung eines Verfahrens zum Herstellen eines ovalförmigen Rohrabschnittes aus einem kreisrunden Rohrabschnitt unter Verwendung einer dreidimensional wellenförmig strukturierten Materialbahn vor dem Verformen zum ovalförmigen Rohrabschnitt;

Fig. 12

eine weitere schematische Darstellung zur Erläuterung des Verfahrens zum Herstellen des ovalförmigen Rohrabschnittes aus dem kreisrunden Rohrabschnitt unter Verwendung der dreidimensional wellenförmig strukturierten Materialbahn nach dem Verformen zum ovalförmigen Rohrabschnitt;

Fig. 13

eine schematische Darstellung einer in ihrer Laufrichtung gebogenen, dreidimensional wellenförmig strukturierten Materialbahn im Querschnitt mit zwei Strukturen in einer Krümmung im oberen Bild und mit einer einzigen Struktur in der Krümmung im mittleren Bild sowie eine dreidimensional wellenförmig strukturierte Materialbahn vor der Verformung (Bild unten links) und nach der Verformung (Bild unten rechts) in Draufsicht;

Fig. 14

eine schematische Darstellung eines Abschnitts einer geschwungenen Motorhaube für den Fußgängerschutz mit einer inneren Verstärkungsschale aus einer dreidimensional wellenförmig strukturierten Materialbahn und einer äußeren glatten Motorhaubenschale; und

Fig. 15

eine schematische Darstellung zum Erläutern des Herstellens einer bekannten beul- / wölbstrukturierten Materialbahn (oberes Bild links), einer dreidimensional wellenförmig strukturierten Materialbahn mit elastischer Zwischenlage (unteres Bild links), einer dreidimensional wellenförmig strukturierten Materialbahn bei einer größeren Stützelementwalze mit breiteren, starren Stützelementen ohne elastische Zwischenlage (oberes Bild rechts) und einer dreidimensional wellenförmig strukturierten Materialbahn mit einer Stützelementwalze mit einer reduzierten Anzahl von Strukturen auf dem Umfang sowie mit einer elastischen Zwischenlage.

The invention is explained below with reference to embodiments with reference to figures of a drawing. Hereby show:

Fig. 1

schematically an apparatus for producing a conventional bulge / vault structured material web according to the prior art;

Fig. 2

schematically an apparatus for producing a wavy and three-dimensionally formed structuring of a material web by means of a transported elastic intermediate layer according to the invention;

Fig. 3

in the upper picture, the cross-section through a thin-walled round cylinder (dashed circle) and a sinusoidal, elastic wave (solid line), which occurs at low external, all-round hydraulic pressure load (before the dynamic breakdown), and in the lower picture a "garland-shaped" Shaft after dynamic breakdown (with increased external, all-round hydraulic pressure load);

Fig. 4

in the upper picture the cross-section of a three-dimensionally wavy structured material web in section along a line A - A and in section along a line BB and in the lower picture the corresponding plan view with the positioning of these two sections;

Fig. 5

schematically an apparatus for producing a three-dimensional wavy structured material web by means of a core with wide support elements (upper part) and a plan view of a section of the three-dimensional wave-shaped structured material web (lower part);

Fig. 6

the cross section through a three-dimensional wave-shaped structured material web with incident and reflected light rays;

Fig. 7

a section of a hood in cross-section and a reinforcing shell in plan view;

Fig. 8

in cross section a portion of a hood for pedestrian protection with an inner reinforcing shell of a three-dimensional wave-shaped structured material web;

Fig. 9

a section of a thin-walled tube in cross-section of a three-dimensional wavy-structured thin-walled material;

Fig. 10

in the upper picture, the cross section through a structured, thin and dimensionally stable wall of a three-dimensionally wave-shaped structured material web and in the lower picture the cross section through a sandwich of an upper and lower belt of a three-dimensional wavy structured material web;

Fig. 11

a schematic representation for explaining a method for producing an oval-shaped pipe section of a circular pipe section using a three-dimensionally wave-shaped structured material web before forming the oval-shaped pipe section;

Fig. 12

a further schematic representation for explaining the method for producing the oval-shaped pipe section from the circular pipe section using the three-dimensional wave-shaped structured material web after deformation to the oval-shaped pipe section;

Fig. 13

a schematic representation of a curved in their direction, three-dimensional wave-structured material web in cross-section with two structures in a curve in the upper image and a single structure in the curvature in the middle image and a three-dimensional wave-shaped structured material web before deformation (bottom left) and after deformation (bottom right picture) in plan view;

Fig. 14

a schematic representation of a portion of a curved hood for pedestrian protection with an inner reinforcing shell of a three-dimensional wave-shaped structured material web and an outer smooth hood shell; and

Fig. 15

a schematic representation for explaining the production of a known bulge / wölbstrukturierten material web (upper image left), a three-dimensional wavy structured material web with elastic intermediate layer (lower image left), a three-dimensional wavy structured material web at a larger support element roller with wider, rigid support elements without elastic Intermediate layer (top right picture) and a three-dimensional wavy structured material web with a support roller with a reduced number of structures on the circumference and with an elastic intermediate layer.

In the following, the production of a material web from a web material having a wave-shaped and three-dimensionally formed structuring will first be described with reference to FIGS. 1 to 14. For the same features, the same reference numerals are used in Figs.

1 shows schematically an apparatus for producing a conventional bulge / vault structured material web 9 according to the prior art with a support element core 3 and an elastic pressure roller 4. The disadvantage is that the bulge / vault structured material web 9, which consists of folds 10 (FIG. considerably more plasticized) and troughs 11 (comparatively flatter and more flattened), closely nestles during structuring of the support element core 3 and therefore leaves the structuring system with a very strong curvature. Therefore, the folds 10 and the troughs 11 are additionally deformed during subsequent straightening in the planar shape and thereby significantly plasticized.

Fig. 2 shows schematically an apparatus for producing a wavy and three-dimensionally formed structuring of a material web 2, wherein a resilient pressure roller 4 presses a smooth material web 1 against an elastic intermediate layer 5 and the intermediate layer 5 against a support element core 3. By impressing the elastomer of the intermediate layer 5 in the region of the effective support element, a "common" adapted, wider support element arises, consisting of the rigid support element 3 and the pressed-on elastomer 5, which produces comparatively wide beads 6 in the material web 2.

The zig-zag-shaped beads can be seen in Fig. 2 only as line 7. In this way, and further by the frictional engagement between the "flow" of the elastomer of the intermediate layer 5 (crushed elastomer immediately at the flanks of the support member) and the material web, the material web is uniformly deformed in the region of the beads 6 and comparatively only very little plasticized. Therefore, the contact pressure of the elastic pressure roller 4 can be further increased to produce even deep dome 8 in the structured material web 2 without the material tearing. The calottes 8 are preferably given an approximately spherical dome shape in hexagonal support elements. The three-dimensionally wave-shaped structured material web 2 exits from the structuring plant with a smaller curvature (so-called coil set) than is the case in FIG. 1. The structured material web 2 in FIG. 2 is somewhat prepared. The downstream alignment unit is not explicitly shown.

Fig. 3 shows in the upper part of the cross section through a thin-walled round cylinder (dashed circle) and the sinusoidal, elastic shaft 12 (solid line), which adjusts at low external, all-round hydraulic pressure load (before the dynamic breakdown). The lower image shows after the dynamic breakdown with increased external, all-round hydraulic pressure load comparable to the known Beulstrukturieren, "garland-shaped" wave, which consists of the Beulfalten 10 and the bulge 11. When penetrating the outer sine half-waves 12 (upper part in Fig. 3) pull together for Beulfalte 10 (lower part in Fig. 3). In this way, the bulge 11 is in the form of an inner cosine half-wave, wherein the wavelength of this cosine half-wave is twice as large as that of the original sine half-wave. Due to the dynamic, not yet damped breakdown in the known buckling / vault structuring, the known Beulfalten 10 form with their very tight bending radii.

4 shows in the upper picture the cross section of a three-dimensional wave-shaped structured material web 2 in section A - A and in section B - B and in the lower picture the corresponding plan view with the positioning of these two sections. By directing the curved, structured material web into the planar shape, the zig-zag-shaped beads 7 in FIG Direction of the web 2 (see arrow in the production direction in the lower picture) slightly compressed and the beads 6 transversely to the direction of the web 2 slightly stretched. Therefore, the structural height of the beads and the dome in section A - A is greater than in section B - B.

Fig. 5 shows in the upper part schematically an apparatus for producing a three-dimensionally wave-shaped structured material web 2 with wide support elements 13 on the support element core 3 and an elastic pressure roller 4. The width and the rounding of the support elements 13 preferably correspond to the width of the "common" adapted support element from the rigid support member and the pressed-on elastomer, whereby the comparatively wide beads 14 (modeled from the beads 6 in the material web 2 of FIG. 2) were produced.

So that the rounded contour of the adapted wide support elements 13 is actually transmitted to the contour of the beads 6 of the web by pressing the pressure roller 4, the elastomer of the pressure roller 4 in Fig. 5 without elastic intermediate layer 5 preferably receives a slightly higher Shore hardness than that For example, while the elastomer of the pressure roller 4 has a Shore hardness 60 in FIGS. 1 and 2, the elastomer of the pressure roller 4 in FIG. 5 having a Shore hardness 65 to be equipped to 70.

Since the self-adjusting beads 6 are much larger than the narrow folds 10 in the known buckling / vaulting patterning process in FIG Fig. 2 and 5, the contact pressure of the pressure roller 4 are still significantly increased against the web to be structured, without the material of the web breaks. Thus, comparatively deep structures can be produced, for example, for the crash energy absorption of a hood or for sandwich structures with large wall stiffening due to a large moment of inertia at comparatively low weight or for example for a flow channel or a heat exchanger of two or more layered and interconnected structured material webs with a comparatively large flow cross-section, for example for gas-gas heat exchangers, are produced. For example, can with the help of a hexagonal structure of the wrench size 50mm a 0.6mm thick sheet of sheet steel according to the method in Fig. 5 a structure depth of more than 6mm can be achieved, while realized by the known buckling / Völbstrukturierungsverfahren in Fig. 1 only a structural depth of about 4mm can be. 5, the structured material web 2 is shown in a partially preformed shape (downstream alignment unit is not explicitly shown).

6 shows the cross section through a three-dimensionally wave-shaped structured material web 2 with deep, approximately spherical domes 8 for a broad, diffused light scattering. The three images show the reflection of the light in a uniform and broadly diffuse light scattering, which results from the fact that the incident light rays are reflected point-like and at the same time broadly diffuse at the uniformly curved and at the same time deep domes 8. This results in a glare-free or at least a very low-glare reflected light. If a less widely scattered light reflection is desired, flatter domes 8 are produced in that preferably the material web 1 is subjected to a lower pressure by the pressure roller 4 during structuring. Again, this results in a uniformly curved dome 8 in the material web, which ensures a punctiform light reflection. The upper image and the middle image show that due to the approximately spherical cap shape even with different angle of incidence of the light, a point-like, diffuse light reflection is achieved. The lower picture shows an example of a directed, diffused light scattering.

Fig. 7 shows schematically in the upper picture the cross section through a hood for pedestrian protection with an inner, slightly curved reinforcing shell of a three-dimensional wavy structured material web 2. This structured material web is at their beads 6, 7 with the outer smooth bonnet shell 15 preferably by linear Splices 16 connected. The three-dimensionally wave-shaped structured material web 2 can be adapted to the contour of the only slightly curved, outer hood shell 15 with the aid of simple embossing or calibration tools, which consist of rigid or elastic materials, because the three-dimensionally wave-shaped structured material web 2, in particular even in deep structures large multi-dimensional bending and yield reserves, without the Structures (dome and ridges) are leveled again or locally buckling. The particularly large forming reserves of this structured material web 2 even allow complex, geometric adjustments to individually designed outer hood shells. The same applies to other reinforcing shells in the vehicle area, such as doors, roofs, fenders, tailgates, parcel shelves and lower and side partitions.

8 shows the cross section through a hood for pedestrian protection with an inner reinforcing shell made of a three-dimensionally wave-shaped material web 2. The structured reinforcing shell is preferably connected by splices 17 to the dome 8 of the structured material web 2 with the outer, smooth hood shell 15. For further applications, the examples given for FIG. 7 apply.

9 shows the cross section through a thin-walled pipe section 18 made of a material web 2 structured in a three-dimensionally wave-shaped manner. This simplified illustration shows only the visible edge of the cut thin-walled pipe section 18 with the beads 6 and the domes 8. On the representation of the structures in the center of the thin-walled pipe section 18 was omitted.

When cans are produced or cans are transported, the beads 6 and 7, which are considerably wider than the known folds, are less susceptible to lateral and punctiform impacts. The same applies to plastic bottles, in particular for PET bottles.

When using thin-walled pipe sections from the three-dimensional wave-structured material webs as Läuterkammerrohr, crucible or stirrer shaft of platinum alloys for the molten glass and the outgassing of the molten glass, considerable advantages arise because in the thermal expansion obstruction due to the extreme thermal cycling during startup and shutdown of the system wide beads 6 can distribute the occurring stresses much more evenly and therefore more gentle on the material.

In the abovementioned applications of the three-dimensionally wave-shaped structured material webs, independent advantages in each of the various technical fields result in addition to the explained general advantages of the three-dimensionally wave-shaped structured material webs.

10 shows in the upper picture the cross section through a structured, thin and at the same time dimensionally stable wall of a three-dimensional wave-structured material web 2. The lower picture shows the cross section through a sandwich of an upper and lower belt made of a three-dimensional wave-structured material web 2 and a inner plastic or plastic foam core 20.

11 and 12 show a schematic representation for explaining a method for producing an oval-shaped pipe section 25 (see FIG. 12) from a circular pipe section 22 (see FIG. 11) using a three-dimensionally wave-shaped structured material web.

Fig. 11 shows the state before deformation, and Fig. 12 shows the state after deformation. 11 shows a cross section through a circular three-dimensional wave-shaped structured tube 22 with circumferential beads along the line 7 and axial beads 6 and calottes 8 and two rigid or elastomeric pressure rollers 24. The lower image in FIG. 11 shows the plan view on the unwound material web 23 (viewing direction from the projection of the pipe section 22) in the projection of the pipe section 22.

Fig. 12 shows in the upper picture the oval shaped tube section 25 which has been converted by the pressing of the pressure rollers 24 and optionally the additional rigid or elastic pressure rollers 27 in the desired oval shape. Instead of the pressure rollers 24 and 27 and elastic or rigid molded cushion or pressure elements can be used. Experimental studies have shown that it is not necessary to form the three-dimensionally wave-shaped pressure rollers 24 and 27, mold pads or printing elements with a negative mold equip structured material web. In the simplest case, even simple finger or hand movements are sufficient to complete the transformation into the oval shape.

Another method design provides that when tight bending with a small bending radius of the circular three-dimensional wavy structured material web 22 in the oval-shaped of the tube section 25, the beads 6 and 7 independently "deform" claim stressful and thereby of the hexagonal arrangement of the beads 6 and 7 with increasing curvature (corresponding to decreasing radius of curvature) of the oval continuously (ie without kinks in the troughs and ridges) merges into a common, approximately serpentine bead transverse to the direction of the web.

In the lower image of FIG. 12, the plan view of the developed lateral surface of the oval-shaped pipe section 25 is shown. The circumferential beads 7 (in the running direction of the material web, arrow direction in FIGS. 11 and 12) rotate / interlace to form beads 29 and 31. The axial beads 6 transversely to the running direction of the material web are shortened continuously to form beads 28 and 30. As a result The beads 32 and 34 at the location of the smallest curvature of the oval assume the shape of a common, approximately serpentine bead. All of this happens almost all by itself, ie without the intervention of molds, which have the serpentine negative contour, according to the principle of energy minimization and succeeds with the help of the three-dimensional wavy structured material web with their gently rounded beads and calotte. At the same time, the clear distance between the axial beads 6 (corresponding to the key width of the not yet deformed hexagon) is somewhat reduced, so that the clear distance between the serrated beads 32 is slightly lower, for example, about 10%, than the key width of the original hexagon. These effects explain why the three-dimensional wave-shaped material web can bend tightly into an oval. Therefore, comparatively large and deep structures can be used for the purpose of high overall rigidity of the oval-shaped tube / channel. This is not possible with the buckling / buckling structures known in the prior art because, when the large structures are tightly bent, their depressions and folds buckle, as a result of which the overall rigidity is greatly reduced.

13 shows schematically in the upper and middle picture the cross section through a narrowly curved in its running direction, three-dimensionally wave-shaped structured material web 35. In the upper image, two structural capsules 36 are arranged at the location of the curvature of the material web 35. In the middle image, only a single structural cap 37 is arranged at the location of the curvature. This staggered arrangement of the structural dome at the location of the curvature results from the geometry of the serpentine beads (not visible in cross-section in FIG. 13) in the transverse direction to the running direction (see top view of the unwound material web in the lower image of FIG. 12). However, if the three-dimensionally wave-shaped structured material web (in the bottom left of FIG. 13) is bent alternatively transversely to its running direction, the shortened zigzag beads 7a and, correspondingly, the elongated ones are formed, as shown in FIG Explode 6a at the place of curvature.

Fig. 14 shows schematically, and perspectively only indicated, the cross section through a hood 38 for a vehicle using a three-dimensional wave-shaped reinforcing shell with the beads 6 and 7 and the cap 8. The caps 8 are on their outside, for example by means of adhesive dots 17 with the outer smooth hood shell 15, which is equipped left and right with a curved shape 39, connected. Alternatively, however, the beads 6 and 7 of the three-dimensionally wave-shaped structured material web can be connected to the outer hood shell 15 (not explicitly shown in FIG. 14) by, for example, splices 16 (analogous to FIG. 7). The three-dimensional wave-structured material web / reinforcing shell can be equipped with tight bending radii, such as in the area 40, and at the same time with deep and large structures.

15 shows schematic representations in four images for explaining the production of a multi-dimensionally structured material web with support element core. For simplicity, the illustration of the pressure roller 4 has been omitted. The first image (top left) shows the bulge / vault-structured material web 9, which tightly conforms to the support element core 3 with the radius R1, on whose circumference 8 structures are arranged, during structuring (analogous to FIG. 1).

The second image (bottom left) shows the three-dimensionally wavy structured material web 2 on the support element core 3 with the elastic intermediate layer 5. The three-dimensionally wavy structured material web 2 leaves by itself (ie without influence of a downstream straightening unit) the structuring device with a natural curvature corresponding to the radius of curvature R2 = 1.5 * R1, wherein the size (wrench size of the hexagon) of the structure remains approximately the same (in FIGS. 2 and 5, a material curvature with a larger radius of curvature results because the structured material web 2 in FIG. 2 and FIG 5 has already been "pulled" somewhat flat by a downstream straightening unit).

The third image (top right) shows a three-dimensionally wave-shaped structured material web 2, which closely adheres to the support element core 3 with wider support elements 13 (analogous to FIG. 5) during structuring (without additional elastic intermediate layer 5). The radius R2 of the support element core 3 in the third image (without elastic intermediate layer 5) is equal to the radius R2 of the "naturally" curved material web 2 from the second image (FIG. 15, bottom left). In this way, twelve structures on the circumference of the support element core 3. In this way, the mechanical forming process in three-dimensional wave-like structuring (instead of a narrow rigid support member plus crushed rubber as a "common" support member, a wide rigid support member is used) is modeled.

The fourth image (bottom right) shows a three-dimensionally wave-shaped structured material web 2 on a support element core 3 with an elastic intermediate layer 5. On the support element core 3 are six structures (instead of eight structures in the two images in Fig. 15 with the support element cores 3 and Radius R1), wherein the radius R1 is the same in each case. Thus, the structures of the three-dimensionally wave-shaped structured material web 2 in the image at the bottom right in FIG. 15 obtain a larger key width and at the same time greater structure depth than in the two other structural devices with the support element core radii R1.

The features of the invention disclosed in the foregoing description, in the claims and in the drawing may be of importance both individually and in any combination for the realization of the invention in its various embodiments.

Claims (28)

Structured material web of a web material, in particular sheet material web, having a wavy and three-dimensional structure formed with beads and beads enclosed by the beads, wherein the beads are made continuous and have a curvature opposite to the curvature of the calotte. Material web according to claim 1, characterized in that the calottes in a central Kalottenbereich have a shape which is at least approximated to a spherical shell shape. Material web according to claim 1 or 2, characterized in that the beads are formed contiguously according to one or more basic geometrical forms of the following group of basic geometric shapes: triangle, quadrangle, in particular square, rectangle, rhombus or parallelogram, pentagon, hexagon and Octagon. Material web according to at least one of the preceding claims, characterized in that the beads are formed according to a uniform geometric basic shape. Material web according to at least one of the preceding claims, characterized in that the beads and / or the calotte are each formed with a substantially uniform Wülst- / Kalottenhöhe. Material web according to at least one of the preceding claims, characterized in that the web material is selected from the following group of material: metal, plastic, fibrous materials, in particular paper and cardboard, fiber fabric and mesh fabric. Material web according to at least one of the preceding claims, characterized in that the web material is formed in a sandwich construction, in which at least one intermediate web is arranged between two outer webs. Material web according to at least one of the preceding claims, characterized in that for at least a portion of the calotte a Kalottenoberfläche is broadly diffuse reflective, wherein at least the part of the calotte is formed with the broadly diffusely reflecting Kalottenoberfläche as deep calotte. Material web according to at least one of the preceding claims, characterized in that for at least part of the calotte a Kalottenoberfläche is directionally reflective, wherein at least the part of the calotte is formed with the directionally reflective Kalottenoberfläche as a flat calotte. Material web according to at least one of the preceding claims, characterized in that the web material is anodized aluminum sheet. Material web according to at least one of the preceding claims, characterized in that the wavy and three-dimensional structuring formed as a self-organizing structuring. Material web according to at least one of the preceding claims, characterized by a curved portion which is optionally designed as a bent portion and in which a curvature is formed with a narrow radius of curvature, wherein the beads and calottes are executed buckling in the region of curvature. Material web according to claim 12, characterized in that the curvature is formed in the direction of a curvature on an outwardly directed side of the calotte. Material web according to claim 12 or 13, characterized in that the curvature is at least partially formed in a running direction. Material web according to at least one of the preceding claims, characterized in that the height of the beads in and transverse to the running direction in a ratio of at most about 1: 1.5 (bead height in the direction: bead height transverse to the direction), preferably of at most about 1: 1.3 and further preferably at most about 1: 1.1 stand. Material web according to at least one of the preceding claims, characterized in that a ratio (radius of curvature / material thickness) of a value for the radius of curvature in the region of the calotte to the value of the material thickness of a material web used is at least about 8, preferably at least about 10 and more preferably at least about 15 , Article in which at least one article section is formed using a material web according to one of claims 1 to 16. Article according to claim 17, characterized in that formed with the article section is a pipe section which has an optionally oval or round cross-section. Article according to claim 17 or 18, embodied as articles selected from the following group of articles: light reflector component, crash component for a vehicle, in particular engine hood component, can and pipe component such as ion beam ring pipe or outgassing pipe. Method for producing a structured material web, in particular a structured sheet material web, in which a material web of a web material is provided with a wave-shaped and three-dimensional structuring by means of beads and beads enclosed by the beads, the beads being continuous and are formed with a curvature opposite to the curvature of the calotte. A method according to claim 20, characterized in that the undulating and three-dimensional structuring formed by utilizing a self-organizing structuring process of the web material is formed. A method according to claim 20 or 21, characterized in that the beads and the dome are formed by the material web curved and then by an external pressure on an inner side first against an elastic intermediate layer, which is arranged on rigid support members, and then against the rigid Support elements is pressed. A method according to claim 22, characterized in that an intermediate layer of a material or a combination of materials of the following group of materials is used as the elastic intermediate layer: elastomer, flexible material and fibrous material. A method according to claim 22 or 23, characterized in that a pressure component made of an elastomer or an active medium is used for external pressure pressure. Method according to at least one of claims 22 to 24, characterized in that the rigid support elements are arranged on a core or in a tool, which / has a contour adapted to a desired bead structure of the beads. Method according to at least one of claims 20 to 23, characterized in that the wave-shaped and three-dimensional structure formed with a small curvature ( "coil set ") is formed. Method according to at least one of claims 20 to 26, characterized in that the beads in and transverse to the running direction with a bead height in a ratio of at most about 1: 1.5 (bead height in the direction: bead height transverse to the running direction), preferably of at most about 1: 1.3 and more preferably at most about 1: 1.1 are formed. Method according to at least one of claims 20 to 27, characterized in that the calottes are formed with a radius of curvature which corresponds to a value of the material thickness of a used material web in a ratio (radius of curvature / material thickness) of at least about 8, preferably of at least about 10 and more preferably at least about 15.

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