The invention further comprises a process for producing a structural element according to the precharacterizing clause of Claim 30.

PRIOR ART The German magazine "Solarführer Ulm", issue 1995, pages 11 to 16, discloses a structural element having a covering part for cladding roof and wall surfaces of a building, having a collector device which is placed ready-mounted on a substrate, for example being on a roof surface. The covering part is produced as an individual structural element up to a maximum size of 12 m2. Larger areas are realized by joining a number of structural elements, but this produces a large marginal region at the side region. However, such a marginal region on a solar surface leads to relatively large cooling. The covering part having the integrated collector device is distinguished quite significantly from a conventional roof covering or another substrate. Using the known arrangement, appropriate integration of the structural element with its environment is not possible. The material of the covering part having an outwardly directed outer surface and having an inwardly directed inner surface comprises a thick, translucent and hardened glass pane. However, such a glass pane is rather heavy and leads to a very high loading for the substrate on which the structural element rests.

Underneath the glass pane, at a distance and essentially parallel to it, the collector device is integrated and is of very flat design distributed over one surface of the structural element. An insulating layer for the structural element is provided on a side of the collector facing away from the solar irradiation. Provided underneath this layer is the support for the structural element. The covering plate made of glass is removably arranged on the structural element. The removability of the glass plate is necessary for the installation, either for placing it on the roof or for a production process and a subsequent complete installation on the support. A complete production or assembled installation of the structural element needs a great number of complicated installation steps, which have to be carried out manually with great effort and cannot be automated by means of an automatic production process. The costs for such a structural element are significantly influenced by such installation work and production costs and are thus made more expensive.

The German brochure "Solarfuchs" from the Johann Kalkgruber company in A-4400 Steier, Austria discloses a structural element having a covering part and an integrated collector device for solar energy. The covering part comprises a weather-resistant and prestressed glass pane about 4 mm thick, below which the collector device is arranged. It differs considerably in terms of its optics and its shape from a conventional wall or roof covering.

DE-U-9208387 shows a structural element for a roof which rests on a sub-roof construction and has a roof body with a supporting construction and covering parts which are arranged on mountings and cover the entire arrangement. The covering parts comprise a multiplicity of conventional roof tiles.

In an overlap region between roof tiles that are arranged adjacent to each other and/or above one another, photovoltaic elements, by means of which solar energy can be converted into electric power, are provided on the surface of the roof tiles.

DE-A-28074487 shows a structural element for cladding a roof surface of a building. This arrangement has roof tiles that are joined to one another and rest on a roof support. Each roof tile has in its interior a cavity, in which a collector device for solar energy is arranged (roof-tile collector). These hollow roof tiles are laid on the support. Any desired roof area is covered by assembling individual roof-tile collectors. The individual roof-tile collector of the structural element thus forms a covering part which comprises a solid compact body, with the result that, over the entire roof area, a large marginal region is produced, which leads to high cooling of the overall roof surface. The thermal efficiency of the structural element is reduced thereby in comparison with large-area arrangements having a relatively small marginal region.

DE-A-3000289 describes a complete self-supporting roof, whose roof parts, including the roof covering, correspond to a conventional roof. The entire roof comprises a cast concrete body whose outer surface is profiled in such a way that it is not externally possible to distinguish it from roof areas in the environment. A collector device, which is able to convert the quantity of heat picked up by the roof into heat, is arranged cast in the concrete.

DE-A-3124992 shows a roof element having prefabricated roof bodies to which a collector arrangement for solar energy can be assigned. In this case, the roof bodies are designed as self-supporting ribbed concrete plates and come to lie with their ribs on the outside. The collector device is arranged in depressions between individual ribs. A covering device that is transparent to sunlight and removable covers the depressions. The side facing the sun is smooth and, in its surface structure, corresponds to a conventional glass pane.

US-A-4517958 shows a solar heat arrangement for a building. The roof and the side walls of the building comprise a collector device incorporated in the side walls and the roof. Each wall or the roof is covered on the outside by a covering part, underneath which the collector device is arranged. The covering part has an outwardly directed outer surface, but this is smooth and consists of a translucent glass. A specific structural element for cladding the roof or wall surfaces of the building is not revealed by the arrangement disclosed.

It is very often the case that architects or planning officers reject the cladding of roofs or wall facades because they do not conform in structural and aesthetic terms with the requirements of a local or regional covering. In the case of a subsequent installation on an existing roof or an existing wall, the installation costs of such structural elements, equipped with solar collectors, for covering roof or wall surfaces are high. In addition, such subsequently installed structural elements are very susceptible to faults.

DESCRIPTION OF THE INVENTION It is the object of the invention to provide a structural element according to the precharacterizing clause of Claim 1 which, in terms of weight, appearance and/or dimensions, does not take second place to conventional structural elements. Furthermore, it is intended to specify a production process for such a structural element which, in a manner beneficial to production, proceeds virtually such that it can be automated. According to a further aspect of the invention, it is intended for the structural element to be produced cost-effectively and also installed at the erection site without great outlay on installation.

According to the invention, this object is achieved using the characterizing features of Claim 1, in that the outer surface is dimensioned and profiled in such a way that a regular structure that can be repeated many times is provided, and in that the collector device faces away from the profiled surface and is undetachably connected to the covering part.

The production process for such a structural element is characterized in that at least one strip with raw material unwinds from an unwind device containing at least one roll, then, in a shaping production process, at least one surface of the strip is dimensioned and profiled in such a way that a regular structure that can be repeated many times is produced, the collector device is then fitted to a side facing away from the profiled surface, and a plate-like part that is joined together in this way is then cut to an envisaged length and width of the structural element.

The structural element according to the invention having the covering part for cladding roof and wall surfaces has, on its side envisaged for the outer surface, a regular structure that can be repeated many times which does not stand out visually from buildings in the environment. Such structuring is used in buildings, for example in the form of roughening, for example of wall facades, or as roof tiles or shingles. For this case, the structural element can be used as a replacement or for the repair of a damaged wall or of a roof part. Following installation, the newly used structural element stands out only insignificantly from its environment. By comparison with conventional structural elements having integrated collectors, the structural element is particularly light in weight, is simple, cost-effective and of constant quality in production and, in particular in the processing, is less sensitive and susceptible to damage. The result of this is lower costs per m2. The construction and installation effort is significantly simplified. As a result of the fact that the collector device faces away from the profiled surface and is undetachably connected to the covering part, the covering part and collector device thus form a compact, single-piece component whose production and handling is very straightforward and suitable. The entire structural element is thus a compact covering part which can be used cost-effectively for the envisaged cladding on buildings. Additional assembly or installation work at the erection site are dispensed with.

Because of the compact construction of the structural element, the production process can proceed in a virtually completely automated way. In a manner beneficial to production, a strip material that is supplied on rolls is used as the starting material and is subsequently subjected to a shaping production process in which the profiling of the outer surface that is envisaged for the later use is created. This shaping process step can be implemented in a production line that runs under automation. By means of this process, a visually striking structure can also be produced on the outwardly directed surface of the covering part, in accordance with the requirements. This can be produced, for example, by means of deliberate roughening of the surface. The roughening is carried out either in one layer on one side of the unwinding strip, using a structure that is applied, or else in two layers on both sides of the unwinding strip by turning up or deep-drawing the structure from an upper and/or lower layer of the structural element. However, the structure can also be achieved by the layer to be structured being spot-welded to the surface of the covering part only at some points, and the layer to be structured being pressed under pressure against a mould. The structuring of the surface is realized, for example, using a machine tool having a shaping tool, such as a press producing the structure and acting over the width of the strip or any other device producing such structuring. Further shaping processes considered for this production station include coating, chromatization or galvanizing processes operating cyclically in corresponding installations. In the same production station or in a further production station adjoining the shaping process step, the envisaged collector device is undetachably connected to that side of the unwinding strip that is opposite to the profiled surface. This joining operation is implemented by means of suitable connecting techniques. To this end, for example, a gantry-type welding machine that is as wide as the strip and has spot-welding cylinders that are designed to be as wide as the strip or act one after another, and laterally or transversely acting rolled-seam welding machines or adhesive bonding devices can be used. In the case of an appropriately configured and adapted collector device, this production step is incorporated as the next production station in a production line. Following this joining operation, in a further process step the plate-like part shaped in this way is then cut to the envisaged length and width of the structural element. After running through the individual production stations, it is thus possible for a complete component to be produced, in a production process that can be automated, even "cyclically". This production process quite definitely leads to lower costs in the production of the component. Complicated installation work or assembly from a plurality of individual parts, either during production or at the installation site, are dispensed with.

The multiply repeatable regular structure of the outer surface of the covering part is advantageously arranged in such a way that it has a structure like a tiled roof, slate roof or shingled roof or is arranged to correspond to an external configuration of a wall surface. In many areas, such external facades or roof surfaces are banned by local custom or law. Depending on the location of use of the structural element, a regular roof-tile structure may be adapted to correspond to the external conditions. As a result, for example, a solar roof or a solar wall that is clad with the structural element obtains the structure and the conventional appearance of a roof or of a facade, so that such a wall or such a roof surface is adapted to the other conventional types of roofs or walls without impairing the aesthetics. In order to improve the visual configuration of the structural element, the surface can be adapted in a still more advantageous manner to the environment by means of appropriate visually striking structures, by deliberate admixture of colorants during production.

The structural element can be used particularly advantageously as a large-area structural element, for example if the outer surface has an extent of at least 1 6 m2, or has an edge length of at least 4 m. Structural elements of the type described are particularly suitable for use as a complete roof covering or as cladding for entire walls of such a size. The element is thus suitable as a replacement for a complete roof covering or for cladding complete walls. In this large-area design, the structural element can be used as a roof or as a wall for a building to be erected. The wall or the roof is advantageously produced separately, transported to the location of use and assembled there over the entire area to form a complete building. The large-area design as a complete roof or wall also has the advantage that no intermediate marginal cooling occurs in the integrated collectors, that is to say such regions occur only at the margins of the roof or of the wall. A large covering area of the structural element reduces installation costs on site and does away with the costs for connecting elements.

This structural element, operating completely functionally, makes it possible to use large-area and high-capacity collector elements having a significantly higher or differentiated capacity than the conventional collectors, together with reduced costs and thus to reduce the running energy costs of a building in the same way as, in particular, the initial equipment costs in relation to comparable capacity ranges. Any slightly higher transport costs for such large solar elements, which are only of consequence in the case of large installations, however, are compensated for by the advantages that are provided by the higher power yield.

The utilization of the full area of the entire roof or of the entire wall as a solar roof or as a solar wall also further compensates for the somewhat lower efficiency over the area of this structural element by comparison with that of a conventional element.

Such large-area structural elements are advantageously produced by the strip-like raw material, as a plate-like part, being cut to the appropriate width and length of the structural element. Hence, a half-roof or a complete wall is produced completely "from the conveyor belt" in a manner which is beneficial in terms of production and cost-effective. The finished parts can then advantageously be transported to an erection site and assembled there to form a building. This thus produces a complete, solar-heated prefabricated house, which is associated with considerable financial advantages by comparison with the conventional constructional methods.

It is advantageous for the outer surface of the structure element to consist of a heat-absorbing and low-reflection material. This material is particularly advantageous in relation to the function of the structural element as a solar roof or solar wall. The material considered for the surface of the structural element is in principle all those materials which meet the requirements in relation to thermal insulation and low reflection. The reflectivity can also be reduced and influenced by applying an appropriate layer to the outer surface, for example in the form of paints on a metal. Materials made of mixtures of plastics which meet the thermal absorption requirements can also be used, as can metals, it being preferably possible to use stainless steel, copper, aluminium or an alloy of these metals. The absorption effect of a structural element which consists of this material is particularly slight by comparison with conventional collectors, is simpler, cost-effective and has constant quality in production and, in particular in the processing, is less sensitive and less susceptible to damage than, for example, a conventional covering part made of glass. It can be produced in great lengths and is very cost-effective in the processing. It is further distinguished by a low reflectance, low costs per m2, by the omission of any specific protection against hail and the like. The somewhat lower absorption capacity of a metal surface of the covering part can offer specific advantages in various applications, even in comparison with a glass surface. The metallic outer surface or a surface made of a metal alloy produces, under solar irradiation, a lower increase in temperature of a heat-dissipating medium in a collector device than a glass outer surface. If no heat-consuming load is connected to the connector device, then the so-called steady state temperature is lower in the case of metallic structural elements.

Evaporation of the contents, as in the conventional glass flat collector, is prevented.

As an alternative to the structural element made of metal described above, the design of the outer surface using a nontransparent, mineral material is also advantageous. Concrete with a glass-fibre-rein-forced outer skin can advantageously be used as a quite particularly suitable material for the outer surface of the covering part. Such a concrete outer surface is particularly light by comparison with glazed surfaces, is straightforward, cost-effective and of constant quality in production and, in particular in the processing, is less sensitive and less susceptible to damage. The strip-like starting material with its profiled outer surface in this case expediently forms shuttering for the liquid concrete which is applied by spray-casting or similar processes and forms the outer surface of the covering part. Possible production in great lengths can also be realized very cost-effectively when using this material. The structure of the outer surface of the covering part is thus produced cost-effectively and straightforwardly.

The collector device is advantageously arranged flat and extends essentially parallel to the outer surface of the covering part. Such flat collectors have been assessed positively in practice. They have the advantage that the structural element can be designed to be very flat and does not appear to be significantly thicker.

Various advantageous designs are possible for the arrangement of the collector device in the covering part.

In a first design, an interspace, in which the collector device is arranged, is provided between the outer surface and the inner surface of the covering part, and spacers keep the two surfaces at a distance. The collector device is surrounded by the inner and outer surface, at least over part of its surface, and is integrated flat in the structural element. In this way, the device is largely protected against external damage or attack. In addition, optimum heat transfer from the outer surface to the collector device is enabled. The spacers, which impart a high transverse stability to the structural element, are advantageously arranged in that interspace between the outer and inner surface of the covering part which is not filled by the collector device. The finished structural element therefore advantageously becomes very torsionally rigid both during production and during the installation on site. As a further advantageous configuration of the structural element, the spacers are fitted into the interspace such that they completely surround the collector device and thus completely fill the interspace. Such an arrangement offers the advantage that no hollow places are produced between the inner and outer surface of the covering part. The transverse stability and torsional rigidity of the overall component are thereby increased. Depending on the material used for the spacers, the insulation of the structural element with respect to a support (roof insulation, wall insulation) is advantageously increased.

Such an embodiment of the structural element according to the invention is advantageously produced by the strip-like raw material in each case unwinding from two synchronously unwinding rolls of the unwind device. On each side of a strip, by means of the production operation already described above, appropriate structuring of each side of the strip is produced, the envisaged structuring of the outer surface being applied to one side of a strip and the envisaged inner surface of the covering part being applied to the other side of the same strip. Following this production operation, in each case two different plate-like parts are produced. These two parts are then joined together to form two layers of the plate-like part such that a side of the one layer that is provided for the inner surface comes to lie on that side of the other layer that is provided for the outer surface. During the joining of the two parts to form the covering part, the structuring of one or both contacting surfaces produces, between the contacting sides, an interspace in which room is provided for the installation of a collector device, or the interspace at the point of contact of the two layers itself forms the collector device. The two layers of the strips are undetachably joined together to form a covering part after the installation of the collector device has been carried out. This is produced by spot or surface welding connections, riveted connections or adhesively bonded connections being applied in each case to the surface of the covering part and between turned-up edges of the structured surface. The covering part finally produced is thus a component forming a "sandwich" which advantageously surrounds the collector device either completely or partly. A compact, inherently stable part is produced and is cut to appropriate lengths and widths.

In a further embodiment, the structural element is advantageously configured such that the spacers have outwardly and inwardly directed surfaces which are identical to those of the outer surfaces and inner surfaces of the covering part. In this embodiment, the collector device is cast into the covering part and permanently connected to the latter. Such an arrangement is advantageously suggested when the covering part is produced from concrete. An interspace between the outer surface, collector device and inner surface, as in the embodiment described above, is no longer produced in the case of this embodiment. In the case of this embodiment, too, the strip device of the other embodiment described above and having the structured sides can advantageously be used as shuttering material. The outer surface of the covering part, which is for example produced by means of appropriately shaped shuttering, thus forms the surface provided on the outside of the structural element. The inner surface of this design corresponds to the underside of the structural element.

Such structural elements can advantageously be used as complete walls or as the roof of a prefabricated house.

The previous advantageous designs of the invention were based on the fact that the outer and possibly also the inner surface of the covering part is formed from the same material as the covering part itself, that is to say the profiling of the surfaces is carried out directly on the plate-like body. As an alternative to this arrangement of the surfaces, however, it is also advantageous for a thin covering layer to be applied to the spacers on the outwardly or inwardly directed surfaces of the spacers, or to be applied to an appropriately shaped smooth, plate-like body and to be permanently, undetachably connected to the body by way of the layer. This layer, which is structured in accordance with the requirements, forms the outer and possibly the inner surfaces of the covering part.

Both parts, the layer and the intermediately arranged body, together form the covering part.

In the design with the interposed collector device between the two surfaces of the covering part, it is also advantageous if the collector device virtually completely fills the interspace and serves as a replacement for the spacers mentioned above. This embodiment has the advantage that the interspace between the outer and inner surface is virtually completely occupied by the collector device and filled by the latter.

Such a structural element is advantageously produced by a highly expansible gas being introduced between the contact surfaces that are directed towards each other, after the two layers have been joined. In this case, before the introduction of the expansion gas, the starting material is cut to such dimensions that a processing overhang is produced at the margins of the two plate-like parts.

The two plates are permanently connected to each other at these margins. The gas under pressure is subsequently introduced between the contact surfaces. This gas presses the two surfaces, previously resting on each other, away from each other to form a cavity of a bellied shape. The collector device is installed in this cavity. Then, by means of a further shaping production process, for example a pressure or pressing process that acts on the two parts of the covering part, the collector device is integrated into the covering part and undetachably connected to the latter.

The collector device also faces away from the profiled surface if the covering part advantageously has an inner surface which has a course that is identical to the outer surface and is essentially parallel thereto, and in a cross- section thereto forms elevations and depressions, the collector device being partially surrounded, in the region of the elevation, by the inner surface and the roof and wall surfaces arranged below this surface. The inner and outer surface are arranged parallel to each other in this advantageous design. The elevations and depressions of the two parallel surfaces of the covering part thus have, in cross-section in relation to their surface, so to speak a wave-like or sinusoidal course. In the case of this embodiment, the collector device is arranged under the covering part and is partially surrounded by the part of the covering part that forms the inner surface. The said collector device is advantageously arranged in the region of the covering part which is shaped as a wave crest. The parallel inner and outer surfaces of the covering part may possibly need insulation or a support on which they are fitted to the wall or roof surfaces. Depending on the application, however, such an additional support can also be dispensed with. In this case, the covering part is fastened directly to the support. In the case of this design, a wave valley that forms the surface of the covering part is particularly advantageous as a fastening point for the connection between covering part and substrate.

The collector device advantageously comprises a channel which is connected to inlet and outlet openings, this channel having flowing through it a heat-conducting fluid which flows through the channel in the collector device in a gaseous form, for example in the form of air, or as a liquid. Furthermore, the collector device comprises known structural elements, such as a reflector device, an absorber device and similar components, to make better use of the heat produced by the solar irradiation. In addition, the channel can be inserted into the collector device in the form of appropriately cut components and produced with the latter to form a covering part. Alternatively, depending on the embodiment of the covering part, it is also possible for two structured surfaces which lie facing away from the profiled outer surface of the covering part to be joined together in such a way that their contact surfaces form spaces or interspaces which form a channel in which the fluid can flow.

The inlet and outlet openings to which the fluid is connected are advantageously connected to catching devices which are arranged at the lateral margins of the covering part. Liquids such as rain or snow penetrating from the outside onto the structural element are caught in these catching devices and advantageously provided as the liquid for the collector device. It is possible, for example, for a rain or snow catching device to be provided on the wall or for a condensation gutter or verge of a roof to be provided as the catching device. The condensation discharge used can either be a simple corrugated plate made of plastic or a depression or subconstruction that has the appropriate shape of a hollow throat, gutter, box or corrugation running longitudinally or transversely and is moisture resistant, and can also be used at the same time for the circulation of warm air. In the case of structuring the underside of the covering part, a supporting surface can also be used as a condensation discharge and back- ventilation means.

In the advantageous design of the structural element that has already been described, with the covering part having a roof-surface-structuring or wall-surface-structuring concrete or glass-fibre concrete outer layer of appropriately dimensioned thickness, a chamber and conduit system is inserted into the interior of the covering part as the collector device. This design is supplemented by an additional insulating layer, placed below it, with respect to the underneath parts of a roof or a wall, in the form of a vapour barrier, such as is known, for example from roof coverings.

The channel inside the collector device is advantageously shaped as a pipe with a circular cross- section. This arrangement is suggested when the covering part, as already described above, has a wave-like surface. In the case of this design, the pipe is virtually completely surrounded by the covering part in a region forming a wave crest of the surface.

As an alternative, a design of the channel as a rectangle in cross- sectional shape, having a preferably chamber-like volume, is also advantageous.

By comparison with a tubular channel, such a design is considerably flatter and more torsionally rigid.

If the outer surface of a single covering part extends over the whole surface of one side or of the roof of the building, then in each case only one inlet and outlet opening are required. The advantage of such a configuration of the collector device is that the channel arrangement can be arranged distributed over the whole surface in such a way that the fluid carried therein is carried in the channel for a very long time. Carrying the fluid in the covering part for a long time means that the fluid is heated very intensely by the solar irradiation. The channel arrangement along the surface of the structural element is in this case arranged in the manner which is usual in a collector arrangement, for example meandering or serpentine. The decisive factor is that the irradiation area of the structural element is completely utilized.

However, if for application reasons it is necessary for a plurality of covering parts to be connected together to form a total surface, then it is advantageous for the respective inlet and outlet openings of adjacent covering parts to be connected either in series or parallel.

A further advantageous embodiment of the invention consists in the fact that, on a surface of a large-area covering part in particular, flat openings are provided, perpendicular to the outer surface, and are provided for fitting wall or roof surface elements, such as doors, windows, balconies, dormer ventilators or similar surface-mounted parts. Such surface-mounted parts, which are normally fitted later to a wall or to a roof surface, are advantageously already fitted during the production of the structural element. This embodiment is particularly advantageous in the case of using the structural element as a complete wall or as a roof for a prefabricated house. For this reason, recesses are made on the longitudinal surfaces of the plate-like body or the finished covering part, and are perpendicular to the inner and outer surfaces. Window frames, doors, dormer ventilators or similar build-in parts are then built into these flat openings in the component. After the finishing of the covering part, the feed and discharge devices for the collector device that are necessary for the use are fitted.

Depending on the application, it is also possible for the processing margin that occurs during the production of the component to be used for fastening the structural element to the support. A complete wall or a roof part having the abovedescribed installation parts can therefore be produced in advance in a production shop. The individual parts of the building are then assembled, if appropriate in the same or an adjacent production shop, to form a complete house. The entire building is then transported to an envisaged erection site by a means of transport using a low-loader, helicopters, airship or balloon.

It is further advantageous if photovoltaic elements for the direct conversion of solar energy into electric power are arranged on the outer surfaces of the covering part. This type of design has the advantage that, in addition to obtaining heat from solar energy, its direct conversion into electric power for the building is also possible.

Further advantageous developments of the invention are to be taken from the subclaims and the following description.

The invention is explained in more detail below using exemplary embodiments, with reference to the appended drawings.

BRIEF DESCRIPTIONS OF THE DRAWINGS Fig. 1 shows a plan view of a first exemplary embodiment of the invention.

Figs. 2a) to c) show cross-sections corresponding to the lines A-B, C-D and E-F of Figure 1.

Figs. 3a) to c) show cross-sections corresponding to Fig. 1, but in a different design of the invention.

Figs. 4a) and b) show further embodiments of the invention.

Figs. 5a) to I) show plan views of further designs of the invention similar to that of Fig. 1.

Figs. 6a) to I) show, in sectional illustrations, various arrangements of details of the invention. They correspond to a sectional illustration corresponding to a line G-K of Fig. 2a).

Figs. 7a) to c) show cross-sectional illustrations corresponding to the lines L-M, N-O and P-Q of Figs. 5d), 5e) and 5j).

Fig. 8 shows, in schematic form, a sequential process for the production of a structural element according to the invention.

DECRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Fig. 1 shows, in a plan view, a first embodiment of the invention.

One surface 2 of a structural element 1 for cladding a roof is illustrated. The structural element 1 comprises a single component, with which the complete roof is covered. An outer surface 3 of a covering part 7 of the structural element, which serves as an irradiated area for the solar irradiation, extends in the plane of the drawing. This surface, forming a surface 2 of the structural element 1, has structuring that is directed out of the plane of the drawing, as can be seen from Figs. 2a) to c), Figs. 3a) to c), Figs. 4a) and b) and Figs. 7a) to c). The illustrated surface 2 of the structural element 1 has a regular structure 4 distributed over the surface, which is shaped such that it simulates the roof tiles 5 of the roof of a building, and cannot be distinguished from conventional roof tiles. The structural element 1 thus equates visually to a roof that is covered with conventional roof tiles 5. The surface 2 of the structural element 1 consists of metal, an alloy of metals, ceramic or a mineral material which is not made of glass and is thus difficult to break. The structural element 1 is a large-area element having a longitudinal side 6 of about 4 m length and an area of about 16 m2. Such large- area elements correspond to the area of a conventional gable roof of a building, so that the structural element 1 is used for cladding roof surfaces in this figure description, and as a replacement of a complete roof covering in the following figure descriptions. Also visible, distributed over the entire surface 2, are photovoltaic elements 41, with which the direct conversion of solar energy into electric power is made possible. The appropriate connecting elements for this conversion process are not illustrated, for reasons of clarity.

Figure elements which fulfil identical functions in the following drawings are provided with identical reference symbols.

Figs. 2a) to c) show cross-sections corresponding to the lines A-B, C-D and E-F from Fig. 1. From the illustrations it is possible to see the interior of the structural element 1, which comprises a covering part 7 having an outer surface 3 that can be seen from Fig. 1, an inwardly directed inner surface 8 and a collector device 9 for solar energy that is integrated between the outer and inner surfaces. The collector device 9 faces away from the outer surface 3 in all the sectional shapes of Figs. 2a to c), and undetachably connected to the covering part 7. In all the illustrations, the covering part 7 in each case comprises two plates 10, 11 that are produced from a strip-like material and are illustrated in the figures as two horizontally extending lines 10,11, the course of the upper line illustrating a plate 10 that is arranged at the top and forms the outer surface 3 of the covering part 7. The outer surface 3 has a course corresponding to the sections A-B, C-D, E-F of Fig. 1. The course of the lower line illustrates the lower plate 11. This plate forms the inner surface 8. In all the illustrations of Figs. 2a to c), it has a smooth, non-structured surface, in contrast to the upper plate 10.

Fig. 2a) shows a sectional illustration of Fig. 1 along a line A-B. The sectional illustration consists of an upper and lower line which represent an outer surface 3 and an inner surface 8 of the covering part 7, these surfaces constituting plates 1 0,11 formed from strip-like material. The upper plate 10 has upwardly directed peaks 12 at regular intervals, these peaks representing the course of the outer surface 3 of the structural element 1 in the region of the line A-B and corresponding to simulated roof tiles. Between the peaks 12 illustrated, the upper plate 10 has a flattening region 13, in which the two plates 10,11 rest on each other virtually parallel and without an interspace. The two plates 1 0,11 are fastened to each other in this region 13. Provided at the parallel connecting points 14 of the two plates are spot-welded bonding points, riveted connections, screw connections or other types of fastening. Between the connecting points 14, in the region of the peaks 12, it is possible to see cavities 15 as a result of the structuring 4 of the outer surface 3, in which cavities a collector device 9 having heat-dissipating fluids is provided. In its region illustrated at the top, this connector device is partly surrounded by the outer surface 3, and at the bottom by the inner surface 8. An interspace 15 that still remains between the upper and lower plate is filled with spacers 16. This space is either hollow or partially or completely filled with the material of the spacers 1 6.

Fig. 2b) shows a sectional illustration of Fig. 1 along a line C-D. In this illustration, the structuring 4 of the surface 2 of the upper plate 10 has a course 17 like a staircase, which simulates the course of the roof tile 5 from Fig. 1 in the selected sectional region. In a manner similar to that in Fig. 2a), the result is thus a course of the upper and lower plate 10, 11 with regions in which an interspace 15 is produced and in which the two plates run virtually parallel and in which they are connected to each other at connecting points 14. In the selected sectional region, the interspace 15 has a virtually rectangular or trapezoidal area, which results in chamber-like cavities 18 between the plates. The collector device 9 is arranged in this chamber region 18, and is either arranged in a separate channel system or the chamber arrangement 18 formed is used directly for the transmission of a fluid that has been heated by solar irradiation.

Fig. 2c) shows a further sectional illustration of Fig. 1 along a line E-F. Corresponding to the selected sectional region of Fig. 1, the figure illustrates the structure 4 of the outer surface 3 of the covering part 7 with its upper plates 10 illustrated as the upper line. In this region, the outer surface 3 simulates the central region of the roof tiles 5 of Fig. 1. Since, in this region, the course is only structured to a small extent, a relatively broad region is formed as a result, in which region the upper and lower plates 10,11 run parallel and do not form any cavity as a result of the upper plate being turned up. If the regular structure 5 of the surface 2 of Fig. 1 simulates a further roof tile, the upper plate 10 forms upwardly shaped peaks 12, similar to those of Fig. 1, which in turn form a cavity or interspace 1 5 for the accommodation of the collector device 9. The covering part 7 forming the outer surface 3 and the inner surface 8 is produced in the form of a strip by soldering on or otherwise fitting to a raw material or semifinished product or by raising or deep-drawing the structure on the upper and lower plate 10, 11 and spot-welded or adhesively bonded to the lower plate 11 or else with an identical or other structure. The application can be made in the same operation on the strip of a heat-refracting layer, for example in the case of stainless steel, copper or aluminium by means of anodizing (but only in the case of aluminium, steel dissolves in the anodizing bath), by means of appropriate admixture in the case of plastics or other materials.

Figs. 3a) to c) show cross-sections corresponding to Fig. 1, but in another design of the invention. The interfaces are selected in accordance with Fig. 1, but the structuring of the surface 2 is of a different type from that in Fig. 1.

Figs. 3a) to 3c) show a surface course of the structural element having simple turned-up edges of the structure 4. In the present exemplary embodiment, a flat- tile roof covering 19 of a building is simulated. In the appropriate sectional courses, this is illustrated by two horizontally extending upper and lower lines, which form an upper and lower plate 10,11 of the covering part 7, the upper plate 10 once more constituting the outer surface 3 and the lower plate 11 constituting the inner surface 8. As a result of the simulation of a flat tile 19, the upper plate 10 has only slight elevations 20, in comparison to the course in Figs. 2a) to 2c), for forming interspaces for a collector device 19 that is incorporated in this space. In addition to the sectional shapes of Figs 2a) to c), this embodiment of the invention has additional turned-up edges of the lower plate 11, which simulate the course of the inner surface 8.

Fig. 3a shows a sectional illustration which corresponds to that of Fig. 2a), but the course of the upper plate 10 runs virtually horizontally and without forming cavities or interspaces 15 for the installation of a collector device 9. These cavities 15 are provided in the lower plate 11, forming the inner surface 8, which has downwardly directed bulges 21 at these points. Between the bulges 21, the upper and lower plates 10,11 run parallel. In this parallel region 13, the two plates 1 0,11 are connected to each other at the connecting points 14.

Fig. 3b) shows a sectional illustration which corresponds to that of Fig. 2b) but, as already indicated above, the turning up of the edge of the outer surface 3 of the covering part 7 forming the surface 2 is smaller in comparison to the illustration of Fig. 2b). A plate 11, which forms the inner surface 8 and is illustrated at the bottom in the figure, has structuring 4 which corresponds to that of the upper plate but is directed downwards, with the result that, as in Fig. 2b), a chamber-like course 18 is formed for the interspace 15 between the two plates 10,11, in which interspace the collector device 9 is arranged. There is the opportunity to produce the two plates with the same surface course in one production process and to join them to each other back to back.

Fig. 3c) shows a further sectional illustration which corresponds to that of Fig. 2c). Since the outer surface 3 of the covering part 7 is of flat design in the exemplary embodiment of Figs. 3a) to c), as compared to that of Fig. 1, and is not so sharply profiled, this illustration corresponds to that of Fig. 3a), but rotated through 90°.

Figs. 4a) and b) show further embodiments of the invention. In the course of one surface 2 of a covering part 7, they correspond to the embodiment of Figs. 3a) and 3c), with a relatively flatly structured outer surface 3 and a somewhat more sharply profiled inner surface 8. The difference from the embodiment previously described is that the regions in which upward bulges 21 (in the upper plate) or downward bulges 21 (in the lower plate) which are distributed on the surface are not arranged one above another but are offset by a distance. A bulge 21 in an upper plate 11 is not located directly over a bulge in the lower plate 10. In addition, the downward bulges 21 in the lower plate 10 of Fig.

4a) and Fig. 4b) are of different shapes. They are triangular, rectangular or round.

The corresponding surface structure 4 of the upper and lower plates 10,11 is arranged in a manner offset by a specific region. For the production of the two plates, this means that the embodiment of the invention according to Fig. 1 and the previously described embodiments are virtually identical. It is only the type of regular structure 4 on an outer surface 3 and possibly on the inner surface 8, as is illustrated in Figs. 4a) and b), that distinguishes the embodiments. As a result of the type of joining of the upper and lower plates 1 0,11, offset as illustrated in Figs. 4a) and b), or coincidentally, as illustrated in Figs. 2 and 3, there is thus a great multiplicity of applications of the structural element 1 for different uses and requirements.

Figs. 5a) to I) show plan views of further designs of the invention, similar to a design of Fig. 1. The individual figures illustrate variously shaped roof coverings 22 having different roof tiles 5. The various illustrations of roof coverings 22 show that the structural element 1 is suitable for cladding all the possible regional roof shapes and roof coverings. Using the structural element according to the invention, it is possible to simulate any desired roof surface which is covered with roof tiles. The regular structure of the outer surface 3 of the covering part 7 of the structural element 1 is shaped to simulate the surface 2 of such conventional roof surfaces 22.

Figs. 6a) to I) show, in sectional illustration, various arrangements of details of the invention. They correspond to a longitudinal sectional illustration along a line G-K in Fig. 2a). The arrangement of the collector device 9 within the covering part 7 is illustrated. The different patterns that are illustrated in the various drawings correspond to various possible, differently arranged channel guidance systems 23 for the collector device 9 in the covering part 7. The course of the channel guide 23 can be arranged to be meandering, serpentine or otherwise, as can be seen from Figs. 6a) to 1). The collector device 9 essentially comprises a channel guide arrangement 23 on which a reflector and possibly an absorber device are arranged. For reasons of clarity, the illustration of a reflector and absorber has been omitted. The collector device 9 is illustrated in the individual figures merely as a channel device 23 that is arranged parallel to the surface of the covering part. A marginal region 25 of the covering part 7 is illustrated in a lower region of each illustration of the figures which is not surrounded by the collector device. In the region 25, the plates of the covering part that form the outer surface and the inner surface are undetachably connected to each other. The two plates are likewise connected to each other in the regions in which no structuring is carried out, between the channel guides 23 - distributed in a region on the surface 2 of the covering part 7. The marginal region 25 is produced by an appropriate processing margin being added when cutting the two plates to size.

Figs. 7a) to c) show cross-sectional illustrations corresponding to the lines L-M, N-O and P-Q of Figs. 5d), 5e) and 5j). A cross-section through a structural element 1, to which a concrete layer 24 is applied, is illustrated. This concrete layer corresponds to the outer surface 3 of the covering part 7. Arranged under this layer is an interspace 15, in which a collector device 9 is incorporated.

Arranged under the interspace 15 is a further layer that forms the inner surface 8 of the covering part 7. The interspace 15 between the inner and outer surface is completely filled by spacers 26. The material of the spacers 26 is also made of concrete, whose upper side and lower side correspond to the outer and inner surfaces of the covering part 7 which were described above. In this embodiment, the structural element is a concrete plate having a collector device 9 cast on the inside and a profiled outer surface 2. The structural element rests on a support 27 which, for example, contains a vapour barrier, a roof structural moulding or insulation.

Fig. 8 shows, in schematic form, a production process having different production stations for a structural element for cladding roof or wall surfaces of a building. The illustration shows the production of a covering part which consists of two plates (illustrated at the top and bottom) having a collector device arranged between the plates, the collector device being arranged on a surface of the covering part that faces away from the outer surface. The two production sequences A and B for the production of the two plates are illustrated from left to right as a production sequence proceeding in parallel.

The starting or raw material 28 provided for the production of the plates 1 0,11 is a strip-iike material 39 in the form of a metal sheet which in each case is wound up on a roll 29 and is provided for the production process for the structural element. In a special device 30, this strip material is unwound and fed to a first shaping production process. This is illustrated in the illustration as production station 31, in which the two strips 39 are processed in parallel and synchronously. In this station, the two strips 39 are in each case shaped to form plate-like parts 10,11 having an appropriately structured surface. However, cutting to length is not yet required at this production station.

The production station 31 is illustrated as a press acting over the width of the strip and which, on an appropriately configured mating piece 34, shapes the part 32 located at the top like a staircase 35, and shapes the part located at the bottom in a triangular shape. Other deformation techniques can be used appropriately. In addition, in this production station it is possible for the two parts to be surface-coated or chromatized (which is not illustrated), or a galvanizing layer is applied in the cyclic process. In addition, the heat or reflection behaviour of the covering part can be influenced by means of further known coating processes.

The strips with their surfaces structured in this way are then fed to a further production station 33. The configuration of the profiling of the upper and of the lower plate, respectively, forms a cavity having a channel guide that extends on the surface of the covering part. It is possible for the collector device to be incorporated in this cavity, either upstream of the connection station in the production station 33 or subsequently, after the two plates have been connected.

The collector device is provided in an assembly station and subsequently inserted into the production sequence A, B.

The two unwinding strips and the collector device arranged between these are then fed to a further production station 42. This is illustrated as a joining device in which, for example, a gantry-type welding machine which is known from practice, is as wide as the strip and has spot-welding cylinders which are designed to be as wide as the strip or act one after another connect the two plate-like parts in such a way that the collector device 9 is enclosed by the two plates 10, 11. At the connecting point 14, the two parts are riveted to each other or welded together. Alternatively, this can also be implemented as a connecting point 14 by means of a soldering device.

After the joining operation by way of the production station 42, the two plate-like parts 10,11, which previously unwound in the processing sequence as an unwinding, coherent strip 39, are cut to size to the length and width envisaged for the structural element in a further production station 37. For production reasons, however, the areas that are cut to size in this way are larger by a processing margin 25 (see the illustrations in Fig. 6) than the envisaged area of the structural element. The area of the processing margin forms the margins of the upper plate 10 and lower plate 11 of the structural element 1. These margins are permanently and undetachably connected to each other.

Following the production of the structural element 1, it is possible for further production stations (not illustrated), which can likewise be integrated into the production sequence, to be connected, for example ridge cappings, rainwater gutters or verge cover mouldings can be fitted to the ready-joined covering part 7 in such a station. It is also possible for feed and discharge functions for the collector device 9 to be moulded on, as well as their feed and discharge connecting pieces.

As can be seen from the production process described above, the entire production sequence proceeds in a virtually completely automated way. The individual production stations can be arranged in parallel or in series, in a manner corresponding to a production line that can be automated. In addition, testing stations for tightness and quality requirements, such as are conventional nowadays in a production process, can improve the production process for the structural element. In addition, the production process can further be a part of an automated production process for a building which is produced separately in a factory. A roof of such a prefabricated house is then produced in accordance with the production process described above and mounted complete on the prefabricated house.