WO2023095022A1

WO2023095022A1 - Aircraft component and aircraft

Info

Publication number: WO2023095022A1
Application number: PCT/IB2022/061337
Authority: WO
Inventors: Urs THOMANN
Original assignee: Pilatus Flugzeugwerke Ag
Priority date: 2021-11-23
Filing date: 2022-11-23
Publication date: 2023-06-01
Also published as: DE202021106391U1; EP4436877A1; CH719164B1; CH719164A2

Abstract

In an aircraft component where the aircraft component comprises a metal sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1.6), the metal sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) comprises a normal region (5.1, 5.2, 5.3, 5.4) and a first surface milling region (6.1, 6.2, 6.3, 6.4), wherein a thickness (b.1, b.4) of the metal sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) in the normal region (5.1, 5.2, 5.3, 5.4) is greater than a thickness (c.1, c.4) of the metal sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) in the first surface milling region (6.1, 6.2, 6.3, 6.4).

Description

Title: "Aircraft Component and Aircraft"

technical field

The invention relates to an aircraft component according to the preamble of claim 1. The invention also relates to an aircraft according to claim 10, a method according to claim 12, an aircraft component according to claim 18 and an aircraft according to claim 19.

State of the art

The aviation industry is an area in continuous evolution, in which technical challenges have to be mastered again and again. For example, very different requirements are placed on aircraft, which are not always easily compatible. Aircraft should typically be safe, but at the same time energy-efficient.

A typical disadvantage of airplanes compared to other means of transport is often that airplanes are not very energy-efficient compared to other means of transport. Description of the invention

The aim of the invention is to eliminate or at least to reduce the above disadvantages.

This problem is solved by an aircraft component, the aircraft component comprising a sheet metal, the sheet metal comprising a normal area and a first surface milling area, a sheet metal thickness of the sheet metal in the normal area being greater than a sheet metal thickness of the sheet metal in the first surface milling area.

A surface milling area in the sense of this description is a flat area in which material of a sheet metal has been removed in such a way, in particular by means of milling and/or by means of a milling tool, that the thickness of the sheet metal in this surface milling area is less than in a normal area of the sheet metal , in which there is no surface milling.

The invention solves the problem in that the reduction in the sheet metal thickness in the first surface milling area results in a weight reduction compared to a comparable aircraft component in which the sheet metal has a constant sheet metal thickness and no surface milling area with a reduced sheet metal thickness.

The inventors have surprisingly found that such an aircraft component is comparatively easy to manufacture when sheet metal for such aircraft components is cut using high-speed milling machines. In such cases, the contours of such metal sheets are cut out, for example, from rectangular sheets of aluminum (also referred to as blanks) using high-speed milling (also referred to as high-speed cutting). The inventors have recognized that the described surface milling areas can also be produced on the machines which are used for this high-speed milling, namely by removing sheet metal in certain areas of the blanks. This surface milling can, for example, be carried out in a first work step before the contours are milled out. After creating the surface milling area (or multiple surface milling areas) the circuit board can then simply remain in the high-speed milling machine, and the contours can then be milled out using high-speed milling or holes or the like can be produced in the circuit boards (the holes can either be produced first and then the contours milled out or vice versa). In principle, it is also conceivable to first mill out the contours and/or drill holes or the like, and then in a subsequent work step to produce the surface milling areas according to the invention in the cut sheets, namely by removing sheet metal in certain areas of the blanks previously cut out of the aluminum sheets. Surface milling reduces the volume of the sheet metal, which leads to a reduction in the weight of the aircraft component. If such aircraft components are then installed in aircraft, a considerable weight reduction can be achieved, which improves the energy efficiency of the aircraft.

In principle, it is also possible to produce the surface milling area not by mechanical milling but by chemical milling (also referred to as chemical etching) in the metal sheet. Such chemical milling can be accomplished, for example, with concentrated caustic soda. It is also conceivable that the surface milling area (or even several surface milling areas) is produced in the sheet metal by a combination of mechanical milling and chemical milling.

In advantageous embodiments, the aircraft component is an aircraft component. A considerable weight reduction can be achieved, particularly in aircraft in which large quantities of sheet metal are installed. As an alternative to this, however, it is also possible for the aircraft component not to be an aircraft component, but for example a helicopter component, a drone component or a component of a spacecraft. It is also possible that the vehicle component is not an aircraft component, but quite generally a vehicle component that is used in another vehicle, for example in a train, a car, a truck, a bus or a ship. In other words, it is not absolutely essential for the invention that the vehicle component is an aircraft component. In typical embodiments, a distance between a sheet metal edge and the first surface milling area is at least 10 cm, preferably at least 5 cm, particularly preferably at least 3 cm. The inventors have found that such distances lead to an advantageous relationship between sheet metal stability on the one hand and weight reduction on the other. Alternatively, however, it is also conceivable for the first surface milling area to come closer to an edge of the sheet metal, for example up to 2 cm, 1 cm or all the way to the edge of the sheet metal, at least in certain sections of the aircraft component. In typical embodiments, the distance between the sheet metal edge and the first surface milling area is at least approximately 10 cm, preferably at least approximately 5 cm, particularly preferably at least approximately 3 cm, advantageously at least approximately 2 cm.

In typical embodiments, a distance between a bending edge and the first surface milling area is at least 3 cm, preferably at least 2 cm, particularly preferably at least 1 cm. A “bend edge” is to be understood in particular as an edge at which a sheet metal blank is bent or can be bent by approximately 90 degrees, for example. The inventors have found that such distances between bending edges and the first surface milling area lead to an advantageous balance between stability in the bending area of the metal sheet on the one hand and weight reduction of the aircraft component on the other. As an alternative to the minimum distances mentioned, however, other minimum distances are also possible, for example minimum distances of at least 5 cm or approximately 0.5 cm. It is also possible for the first surface milling area to extend at least in places up to and/or beyond a bending edge. In this description, the term “approximately” is typically to be understood in such a way that it designates a possible tolerance of +/-15%, preferably +/-10%, advantageously +/-5%. In typical embodiments, the distance between the bending edge and the first surface milling area is at least approximately 3 cm, preferably at least approximately 2 cm, particularly preferably at least approximately 1 cm.

In typical embodiments, the sheet metal includes a recess, with a distance between the recess and the first surface milling area at least 3 cm, preferably at least 2 cm, particularly preferably at least 1 cm. The inventors have found that such distances lead to a particularly good balance between stability in the area of recesses on the one hand and weight reduction of the aircraft components on the other. As an alternative to the minimum distances mentioned, however, other minimum distances, for example 5 cm or approximately 0.5 cm, are also conceivable. It is also possible for the first surface milling area to reach up to the recess at least in places. In typical embodiments, a “recess” means a hole or penetration in the metal sheet. In typical embodiments, the distance between the recess and the first surface milling area is at least approximately 3 cm, preferably at least approximately 2 cm, particularly preferably at least approximately 1 cm.

In typical embodiments, the aircraft component is a wing element or an outer skin element or a frame element or a stringer element or a rib element or a cover element or another element. The inventors have recognized that a weight reduction can be achieved particularly well with such elements by means of the surface milling area described.

In typical embodiments, the metal sheet is a light metal sheet, the light metal sheet preferably consisting of aluminum or an aluminum alloy.

In advantageous embodiments, the sheet metal includes a second surface milling area, with a sheet metal thickness of the sheet metal in the second surface milling area being smaller than the sheet metal thickness of the sheet metal in the first surface milling area. Such a configuration of the aircraft component with two surface milling areas is advantageous because it allows more precise control of the balance between stability on the one hand and weight reduction on the other. For example, it is possible to retain the original thickness of the sheet metal in particularly stressed areas, to choose a thinner sheet thickness in less stressed areas, for example the first surface milling area, and to select an even thinner sheet thickness in sheet metal areas that are even less stressed, for example the second surface milling area . In advantageous embodiments, the sheet metal includes a further surface milling area, with a sheet metal thickness of the sheet metal in the further surface milling area being smaller than the sheet metal thickness of the sheet metal in the second surface milling area. This achieves even more precise control of the balance between stability and weight reduction. In advantageous embodiments, there are a total of three, four, five, six or more surface milling areas, in which case the sheet metal can then have a different sheet metal thickness in each of these sheet metal areas. Alternatively, however, it is also possible for several surface milling areas to have the same sheet thickness. By providing such a plurality of surface milling areas, a particularly good control of the balance between stability on the one hand and weight reduction of the aircraft component on the other hand is made possible.

In typical embodiments, the sheet metal thickness in the normal range is approximately 1.27 mm. In typical embodiments, the sheet metal thickness in the first surface milling area and/or in the second surface milling area and/or in the or a further surface milling area is approximately 1 mm. In typical embodiments, the sheet metal thickness in the first surface milling area and/or in the second surface milling area and/or in the or a further surface milling area is approximately 0.8 mm. In typical embodiments, the sheet metal thickness in the first surface milling area and/or in the second surface milling area and/or in the or a further surface milling area is approximately 0.6 mm.

In typical embodiments, the surface milling areas make up at least 40%, preferably at least 60%, advantageously at least 80% of a total area of the sheet metal.

What was said above in relation to the distances between the first surface milling area and the sheet metal edge, the bending edge and the recess can also be applied to the second surface milling area and all other surface milling areas: all these surface milling areas can, like the first surface milling area, have these distances from a bending edge and / or have a recess and / or a sheet metal edge of the sheet. The problem is also solved by an aircraft, comprising an aircraft component according to one of the exemplary embodiments described above, the aircraft preferably being an airplane.

In typical embodiments, the aircraft comprises a plurality of aircraft components corresponding to at least one of the exemplary embodiments described above, the plurality of aircraft components preferably having at least one wing element and/or an outer skin element and/or a frame element and/or a stringer element and/or a rib element and/or a covering element and/or another element.

A method according to the invention for manufacturing an aircraft component includes a surface milling process, in the course of which material is removed from a sheet metal blank in such a way that the sheet metal with the normal area and the first surface milling area is formed.

The sheet metal blank can be, for example, one of the rectangular aluminum sheets or blanks mentioned at the outset. Alternatively, the sheet metal blank can also be a workpiece that has already been contour-milled, ie a sheet metal which is no longer a rectangular sheet of aluminum but typically already has a special, more complex contour. The phrase "constant thickness" means that the thickness of the sheet metal blank does not vary, in other words that the sheet metal blank has the same thickness everywhere. As part of the surface milling process, material, ie sheet metal, is typically removed at certain points of the sheet metal blank, typically in a flat area, and not at other points. "Remove material or sheet metal" is to be understood in such a way that e.g. B. sheet metal is milled away, so that the thickness of the sheet metal blank is reduced where material is milled away. Material is thus typically removed by milling away. In other words, sheet metal particles are removed so that the sheet metal thickness is reduced in this surface milling area. The milling can be, for example, mechanical milling, e.g. B. by means of a mechanical milling machine, in particular a high-speed milling machine. However, typical embodiments may also involve chemical milling or other types of material removal, such as laser material removal or electron beam cutting. The surface milling area is typically where sheet metal has been removed; where no material has been removed is typically the normal range. The term “first surface milling area” is used because, as described above, there can also be a second surface milling area and even at least one further surface milling area in the sheet metal. In order to produce the second surface milling area and possibly further surface milling areas, the second surface milling area and optionally at least one further surface milling area are typically produced in the sheet metal, for example within the first surface milling area. A milling head (also referred to as a milling tool) with a milling head diameter of between 7 mm and 20 mm, preferably between 11 mm and 16 mm, preferably of approximately 13.5 mm, is typically used in the surface milling process.

After the surface milling process, a contour milling process is typically performed. The inventors have found that in certain embodiments it can be advantageous to carry out the contour milling process after the surface milling process, because in this way a suction force with which the sheet metal blank is typically held on a machine table of the milling machine during milling can be maximized during the surface milling process. In contrast, this suction force is smaller for sheet metal blanks that have already been contour-milled because their area is already reduced compared to the rectangular aluminum sheets. The inventors have found that strong forces can occur during a surface milling process, as is carried out within the scope of the invention, and that it is therefore advantageous if the suction force during surface milling is as large as possible, so that the sheet metal blank in which the surface milling is carried out is held as well as possible on the machine table of the milling machine. In advantageous embodiments, the method includes a forming process during which the metal sheet is formed, preferably by means of fluid pressing, with the forming process being carried out after the surface milling process. In typical embodiments, the forming includes, for example, bending at the aforementioned bending edges and/or the production of essentially conical bends at recesses or the like.

In advantageous embodiments, the forming process includes a table assembly step, a covering step and a pressing step.

In typical embodiments, the table-equipment step includes a mold-positioning sub-step, in the context of which a mold is positioned on a machine table of a metalworking machine, preferably a fluid cell press. In typical embodiments, a plurality of molds are positioned on the machine table. In typical embodiments, the molds are not mounted on the machine table. The die or dies typically include positives of the shapes to be formed in the sheet metal. The table assembly step also includes a sheet metal positioning substep, during which the sheet metal is positioned on the forming tool. In advantageous embodiments, the table-equipment step preferably includes a fixing sub-step, during which the metal sheet is fixed on the mold, preferably with the aid of a fixing part and/or with the aid of at least one fixing pin. In typical embodiments, the fixing part is, for example, a sheet metal cover or a steel cover or a sheet metal cover or a steel cover. In typical embodiments, the fixing part includes at least one positive of a mold that is to be molded into the metal sheet and/or molded onto the metal sheet. In typical embodiments, the fixing part is curved. In typical embodiments, the fixing part is curved and includes a plurality of cone shapes. These cone shapes are typically suitable for deforming round recesses in the metal sheet in such a way that conically bent edges on the round recesses are produced in the metal sheet. The inventors have found that a curvature of the fixing part, in particular a concave or convex curvature, can be advantageous in certain cases because such a Press-on pressure of the fixing part can be homogenized on the sheet metal as part of the forming process.

In typical embodiments, the masking step includes a first full masking sub-step of placing a first masking mat over all of the molds and the sheets positioned thereon such that the first masking patch covers all of the molds and the sheets positioned thereon. We are talking about "all molds" here. Of course, this also includes the case that only a single forming tool with sheet metal positioned on it is positioned on the machine table. The covering step preferably further comprises a second complete covering partial step, in the course of which a second covering mat is placed on the first covering mat, so that the second covering mat covers the first covering mat. The second cover mat is typically rolled successively onto the first cover mat before the machine table moves into a pressing area of a fluid cell press. The covering step also preferably includes a partial covering sub-step, during which a partial covering mat is placed on at least one combination of mold and sheet metal positioned on the molding tool (and possibly on the fixing part and fixing pins, if present), so that the partial covering mat covers the combination of mold and metal sheet positioned on the forming tool (and if applicable fixing part and if necessary fixing pins, if present), wherein the partial covering sub-step is preferably carried out before the first complete covering sub-step. In typical embodiments, several combinations of the forming tool and sheet metal positioned on the forming tool are positioned on the machine table and several of these combinations, for example two, three, four or five combinations, are each covered with a partial covering mat. The inventors have found in experiments that better forming results can sometimes be achieved with the aid of such cover mats and/or partial cover mats.

In typical embodiments, the pressing step includes a retraction sub-step, during which the loaded machine table is moved into a press area, and a fluid press sub-step, during which the loaded machine table is subjected to oil pressure in the pressing area, so that the sheet metal is formed. Typically, the oil pressure is applied to the first cover mat or the second cover mat, which means that the metal sheets are indirectly acted upon by the oil pressure. A pressing area membrane is preferably arranged in the pressing area, behind which the oil for generating the oil pressure is arranged, so that the oil of the fluid cell press, in which the pressing area is typically located, does not come into contact with the first and/or the second cover mat and thus leading to contamination.

After the fluid press sub-step, the machine table is typically moved out of the press area and the formed metal sheets are removed.

In typical embodiments of the method, the described forming process is followed by further forming processes, at least for some metal sheets, in particular comprising one or more of the steps and/or partial steps described. In typical embodiments, there is at least one, advantageously at least two, in certain cases at least three further forming processes, each comprising one or more of the steps and/or sub-steps mentioned. The inventors have found in tests that, with the help of a plurality of successive forming processes as described above, more precise forming can be achieved on the sheets in some cases, which can reduce the need for subsequent reshaping of the formed sheets.

In principle, it is also possible to carry out the forming process as a separate process, i.e. with workpieces that have not previously gone through the surface milling process described. In other words, the forming process can also be carried out as an independent method, detached from the surface milling process. In this case, for example, sheet metal for aircraft made of aluminum or aluminum alloys are formed, which have a constant thickness, i.e. do not include a surface milling area. The details described above and below for the forming process also apply analogously to cases in which such sheets are formed without surface milling areas. An aircraft component in an exemplary embodiment of the invention is generated using one of the methods described.

An aircraft in one embodiment of the invention comprises an aircraft component that was created using one of the methods described above.

In typical embodiments, the aircraft component is a direct product of one of the described methods for manufacturing an aircraft component and the aircraft comprises such an aircraft component which is a direct product of one of the described methods for manufacturing an aircraft component.

Brief description of the drawings

In the following, the invention is described in detail by means of drawings, showing:

FIG. 1: schematic representation of a metal sheet of an aircraft component in a first embodiment (top view);

FIG. 2: Sheet metal from FIG. 1 in sectional view;

FIG. 3: schematic representation of a metal sheet of an aircraft component in a second embodiment (top view);

FIG. 4: schematic representation of a metal sheet of an aircraft component in a third embodiment (top view);

FIG. 5: schematic representation of a metal sheet of an aircraft component in a fourth embodiment (top view);

FIG. 6: sheet metal from FIG. 5 in a sectional view; FIG. 7: schematic representation of an aircraft according to the invention in an embodiment of the invention (bottom view);

FIG. 8: schematic representation of an aircraft according to the invention in a further embodiment of the invention (bottom view);

FIG. 9: schematic representation of a first exemplary embodiment of a method according to the invention as a block diagram;

FIG. 10: schematic representation of a second exemplary embodiment of a method according to the invention as a block diagram; and

FIG. 11: schematic representation of a partial aspect of a method according to the invention in a side view.

Description of preferred embodiments

Figure 1 shows a schematic representation of a sheet metal 1.1 of an aircraft component in a first embodiment in plan view. The sheet metal 1.1 comprises a normal area 5.1 and a first surface milling area 6.1. The sheet metal 1.1 also includes a sheet metal edge 8. The first surface milling area 6.1 does not quite reach the sheet metal edge 8. Rather, the first surface milling area 6.1 maintains a distance a from the edge 8 of the sheet metal. A sheet thickness of the sheet 1.1 in the normal area 5.1 is greater than a sheet thickness of the sheet 1.1 in the first surface milling area 6.1. However, this cannot be seen in FIG. 1, since the metal sheet 1.1 is shown in FIG. 1 in a plan view, as already mentioned. A section line A - A' defines a vertical section through the sheet metal 1.1 shown in FIG. 1 in plan view.

Figure 2 shows the section AA 'through the sheet metal 1.1, which is shown in Figure 1 in plan view. FIG. 2 now clearly shows that the sheet metal 1.1 has a sheet thickness b.1 in the normal area 5.1, and that the sheet metal 1.1 is in the first surface milling area 6.1 has a sheet thickness c.1, the sheet thickness b.1 of the sheet 1 .1 in the normal range

5.1 is greater than the sheet thickness c.1 of the sheet 1 .1 in the first surface milling area 6.1.

FIG. 3 shows a schematic representation of a metal sheet 1.2 of an aircraft component in a second embodiment in plan view. The sheet metal 1.2 also includes a normal area 5.2 and a first area milling area 6.2. The sheet thickness of the sheet 1.2 in the first surface milling area 6.2 is smaller than the sheet thickness of the sheet 1.2 in the normal area 5.2. However, the different sheet metal thicknesses cannot be seen in FIG. 3 due to the top view representation. The metal sheet 1.2 in FIG. 3 also includes a bending edge 9, which is shown in dashed lines. In a further processing step, the metal sheet 1.2 can be bent by approximately 90 degrees at this bending edge, for example. The first surface milling area 6.2 maintains a distance d from the bending edge 9. In the embodiment shown in FIG. 3, material is saved in the first surface milling area 6.1, which leads to a weight saving, while at the same time the sheet metal 1.2 is kept sufficiently thick in the area of the bending edge 9 in order to have sufficiently high stability at the bending edge 9.

FIG. 4 shows a schematic representation of a sheet metal 1.3 of an aircraft component in a third embodiment in plan view. The sheet metal 1 .3 also includes a normal area 5.3 and a first area milling area 6.3. The metal sheet 1.3 is thicker in the normal area 5.3 than in the first surface milling area 6.3 (this is again not visible in FIG. 4, since FIG. 4 shows the metal sheet 1.3 in a plan view). The metal sheet 1.3 in FIG. 4 also includes a recess 10 in the form of a circular hole in the metal sheet 1.3. The first surface milling area 6.3 maintains a distance e from the recess 10. This saves material in the first surface milling area 6.3, which leads to a reduction in the weight of the metal sheet 1.3, while the greatest possible stability of the metal sheet 1.3 is maintained in the area of the recess 10.

FIG. 5 shows a schematic representation of a sheet metal 1.4 of an aircraft component in a fourth embodiment in plan view. In this embodiment, too, the sheet metal 1.4 comprises a normal area 5.4 and a first surface milling area 6.4. A sheet thickness of the sheet 1.4 in the normal range 5.4 is greater than a sheet thickness of the sheet 1 .4 in the first surface milling area 6.4. In other words, the metal sheet 1.4 is thinner in the first surface milling area 6.4 than in the normal area 5.4. In the embodiment shown in Figure 5, the sheet metal 1 .4 also includes a second surface milling area 7. In contrast to the first surface milling area 6.4, the second surface milling area 7 is not rectangular but elliptical. The sheet metal thickness of sheet metal 1.4 in the second surface milling area 7 is less than the sheet metal thickness of sheet metal 1.4 in the first surface milling area 6.4. FIG. 5 also shows a section line B-B′, which runs vertically through the metal sheet 1.4 and intersects the normal area 5.4, the first surface milling area 6.4 and the second surface milling area 7.

FIG. 6 now shows the metal sheet 1.4, which was already shown in a plan view in FIG. 5, in a sectional view BB'. FIG. 6 shows a sheet thickness b.4 in the normal area 5.4 of the sheet 1.4. Furthermore, there is a sheet thickness c.4 in the first surface milling area

6.4 of the sheet 1 .4 drawn. In addition, FIG. 6 is also a sheet thickness f of the sheet

1.4 drawn in the second surface milling area 7. It can be seen that the sheet thickness c.4 of the first surface milling area 6.4 is smaller than the sheet thickness b.4 in the normal area 5.4. It can also be seen that the sheet metal thickness f in the second surface milling area 7 is smaller than the sheet metal thickness c.4 in the first surface milling area 6.4. The sheet thickness f in the second surface milling area 7 is therefore also smaller than the sheet thickness b.4 in the normal area 5.4. In other words, the metal sheet 1.4 is thickest in the normal area 5.4 and thinnest in the second surface milling area 7. In the first surface milling area 6.4, the sheet thickness c.4 lies between the sheet thickness b.4 of the normal area 5.4 and the sheet thickness f of the second surface milling area 7.

FIG. 7 shows a schematic representation of an aircraft according to the invention in an embodiment of the invention in a view from below. In particular, FIG. 7 shows an aircraft 2.1, in particular a turboprop aircraft. The aircraft 2.1 includes a single propeller, which is located at the nose of the aircraft 2.1. The aircraft 2.1 includes a wing 3, which includes a sheet metal 1.5 of an aircraft component according to the invention. The metal sheet 1.5 can, for example, correspond to one of the metal sheets 1.1 to 1.4 of the previous embodiments or have a different shape or configuration. In Figure 7, the aircraft component thus has the form of a sheet 1.5, the sheet 1.5 a Includes normal area and a first surface milling area, wherein a sheet metal thickness of sheet metal 1.5 in the normal area is greater than a sheet metal thickness of sheet metal 1.5 in the first surface milling area. However, these different thicknesses of the metal sheet 1.5 are not shown in FIG. 7 for the sake of simplicity. The aircraft component, which is formed by sheet metal 1.5 in FIG. 7, is a wing element and is arranged in wing 3 of aircraft 2.1.

FIG. 8 shows a schematic representation of an aircraft according to the invention in a further embodiment of the invention in a view from below. In particular, FIG. 8 shows an aircraft 2.2 which includes a fuselage 4. The aircraft 2.2 is a jet aircraft with two jet engines, which are arranged in the area of a tail of the aircraft 2.2. An aircraft component according to the invention comprising a sheet metal 1.6 is shown in the fuselage 4 . The aircraft component in FIG. 8 is an outer skin element of the aircraft 2.2, in particular an outer skin element on an underside of the fuselage 4 of the aircraft 2.2. The metal sheet 1.6 is shown only schematically in FIG. 8, which means that different thicknesses of the metal sheet 1.6 are not shown in FIG. However, sheet metal 1.6 in any case comprises a normal area and a first surface milling area, with a sheet metal thickness of sheet metal 1.6 in the normal area being greater than a sheet metal thickness of sheet metal 1.6 in the first surface milling area. It is possible, for example, that the metal sheet 1.6 is one of the metal sheets 1.1 to 1.4 shown in FIGS.

In a further, not explicitly illustrated embodiment, a sheet metal is described as above, i.e. in particular a sheet metal with a normal area and a first surface milling area, wherein a sheet metal thickness of the sheet metal in the normal area is greater than a sheet metal thickness of the sheet metal in the first surface milling area, not in one aircraft, but used in another vehicle. Such another vehicle can be, for example, a train, a ship, a bus, a truck, a car or the like.

FIG. 9 shows a schematic representation of a first exemplary embodiment of a method according to the invention as a block diagram. In particular, in FIG Surface milling process P1 and a forming process P2 shown. As part of the surface milling process P1, material is removed in places from a sheet metal blank, resulting in a sheet metal with a normal area and a first surface milling area. In the surface milling area of the resulting sheet metal, a sheet thickness is then less than a sheet thickness in the normal area. The forming process P2 includes a table loading step S1, a covering step S2 and a pressing step S3.

The table loading step S1 includes a mold positioning sub-step S1.1 and a sheet metal positioning sub-step S1.2. As part of the mold positioning sub-step S1.1, at least one mold, typically made of steel, is positioned on a machine table of a fluid cell press. The mold is not fixed on the machine table, but simply placed on the machine table. In some embodiments, several molds are positioned on the machine table as part of the mold positioning sub-step S1.1. The sheet metal positioning sub-step S1.2 follows the mold positioning sub-step S1.1. As part of this sheet metal positioning sub-step S1.2, a sheet metal that has previously been treated as part of the surface milling process P1 is positioned on the forming tool. In a case where there are several forming tools, it is also possible that further sheets are positioned on the other forming tools. In some embodiments, other workpieces, in particular sheet metal, which have not previously been surface-milled, are also positioned on corresponding molds. The forming tools typically include male molds that correspond to the geometric shapes that are to be formed in the sheet or sheets or other workpieces.

The subsequent covering step S2 comprises a first complete covering partial step S2.1 and a second complete covering partial step S2.2. As part of the first complete covering step S2.1, all molds located on the machine table are covered with a plastic covering mat. The cover mat typically has a thickness between 3 mm and 3 cm, preferably between 5 mm and 2.5 cm, advantageously between 1 cm and 2 cm. In the subsequent second full coverage sub-step S2.2, the first cover mat is still from covered by a second cover mat, so that the molds on the machine table and the metal sheets placed on the molds are covered by the first cover mat and the second cover mat.

The covering step S2 is followed by the pressing step S3, which includes a running-in sub-step S3.1 and a fluid-pressing sub-step S3.2. As part of the insertion sub-step S3.1, the loaded machine table, including the first cover mat and the second cover mat, is moved into a pressing area of the fluid cell press. In the subsequent fluid press step S3.2, an oil pressure of approximately 1000 bar is applied to the second cover mat and thus also to the first cover mat and the metal sheets located on the forming tools and possibly other workpieces in the pressing area. This oil pressure causes the sheets to deform according to the shapes of the forming tools, in particular by flow deformation. The cover mats ensure a suitable pressure distribution over the entire machine table.

In advantageous embodiments, the second cover mat is successively unrolled onto the first cover mat during the retraction sub-step S3.1. In other words, the covering step S2 and the pressing step S3, in particular the running-in partial step S3.1, overlap in advantageous embodiments.

FIG. 10 shows a schematic representation of a second exemplary embodiment of a method according to the invention as a block diagram. Like the exemplary embodiment in FIG. 9, the exemplary embodiment in FIG. 10 also includes a surface milling process P1 and a forming process P2. The surface milling process P1 corresponds exactly to the surface milling process P1, which is shown in FIG. The forming process P2 also includes a table assembly step S1, a covering step S2 and a pressing step S3. The pressing step S3 corresponds exactly to the pressing step S3 shown in FIG.

In addition to the mold positioning sub-step S1.1 already described above in relation to FIG. 9 and the sheet metal positioning sub-step S1.2 also already described above in relation to FIG .3. As part of this fixing sub-step S1.3 on the Sheets or other workpieces, which are on the or the mold (s), applied fixing parts to z. B. to fix the sheets on the molds. These fixing parts can, for example, be fixed on the molds with the aid of fixing pins, which reach through the metal sheets and engage in the molds. In advantageous embodiments, a fixing part is applied to at least one metal sheet. In typical embodiments, some of these fixing parts comprise positive molds which are intended to be molded into the metal sheets.

The covering step S2 also includes a partial step which was not yet shown in the exemplary embodiment shown in FIG. 9, namely the partial covering partial step S2.3. This partial coverage sub-step S2.3 is performed in the coverage step S2 before the first complete coverage sub-step S2.1. As part of the partial covering step S2.3, in typical embodiments, a partial covering mat is arranged at least on a combination of a forming tool, a metal sheet positioned thereon and a fixing part positioned on the metal sheet. In typical embodiments, as part of the partial covering sub-step S2.3, a partial covering mat is arranged on a combination of mold and sheet metal. In typical embodiments, the partial covering mat has a thickness of between 3 mm and 3 cm, preferably between 5 mm and 2.5 cm, advantageously between 1 cm and 2 cm. In typical embodiments, the partial cover mat consists of plastic, preferably the same plastic as the first cover mat. The inventors have found that the use of such partial covering mats can lead to more precise forming results for some metal sheets. With regard to the first complete coverage sub-step S3.1 and the second complete coverage sub-step S3.2, which are shown in FIG. 10, the explanations given above in relation to FIG. 9 otherwise apply.

FIG. 11 shows a schematic representation of a partial aspect of a method according to the invention in a side view. In particular, FIG. 11 shows a machine table 11 after the covering step S2 shown in FIG. Three forming tools 12.1, 12.2, 12.3 are positioned on the machine table 11. On the mold 12.1 is a metal sheet 1.7. Sheet metal 1.7 includes a surface milling area, which was previously created as part of a surface milling process became. However, this surface milling area cannot be seen in FIG. 11 because FIG. 11 is a side view and not a sectional view. A fixing part 14.1 is positioned on the sheet metal 1.7. Another workpiece 13 is positioned on the forming tool 12.2, ie a workpiece, e.g. B. an aluminum sheet, in which previously no surface milling area was milled, so which has not gone through the surface milling process P1, which is shown in Figures 9 and 10. A fixing part 14.2 is positioned on the other workpiece 13. A metal sheet 1.8 is placed on the forming tool 12.3. Sheet metal 1.8 includes a surface milling area, which was previously created as part of a surface milling process. However, this surface milling area cannot be seen in FIG. 11 because FIG. 11 is a side view and not a sectional view. On the sheet 1.8 is a fixing part 14.3. positioned. The combination of mold 12.3, sheet metal 1.8 and fixing part 14.3 is covered with a partial covering mat 17. As can be seen in FIG. 11, however, no such partial covering mat is arranged above the other fixing parts 14.1 and 14.2. The entire machine table is also covered by the first cover mat 15, which is thus located above the partial cover mat 17, the fixing part 14.2 and the fixing part 14.1. The first cover mat 15 is additionally covered by a second cover mat 16 . In typical embodiments, the representation shown in FIG. 11 is the arrangement that is present in the pressing area of the fluid cell press after the running-in partial step S3.1 has been carried out.

After the pressing step S3 shown in FIGS. 9 and 10, the machine table is typically moved out of the pressing area again and the formed metal sheets and, if present, other workpieces are removed from the machine table. The forming tools, partial covering mats, covering mats, fixing parts and/or fixing pins, if present, are also removed from the machine table.

In advantageous embodiments, at least one metal sheet is subjected to one, two, three or more further forming processes P2 as described with reference to FIGS. 9 and/or 10. Each of these further forming processes P2 can include a table assembly step S1 and/or a covering step S2 and/or a pressing step S3 and/or a mold positioning sub-step S1.1 and/or a sheet metal positioning sub-step S1.2 and /or a fixing sub-step S1.3 and/or a first complete covering sub-step S2.1 and/or a second Complete covering sub-step S2.2 and/or a partial covering sub-step S2.3 and/or a running-in sub-step S3.1 and/or a fluid-pressing sub-step S3.2. In advantageous embodiments, a plurality of metal sheets is subjected to one, two, three or more further forming processes P2 as described with reference to FIGS. 9 and/or 10. Each of these further forming processes P2 can include a table assembly step S1 and/or a covering step S2 and/or a pressing step S3 and/or a mold positioning sub-step S1.1 and/or a sheet metal positioning sub-step S1 .2 and/or or a fixing sub-step S1.3 and/or a first complete covering sub-step S2.1 and/or a second complete covering sub-step S2.2 and/or a partial covering sub-step S2.3 and/or a running-in sub-step S3.1 and/or a fluid press sub-step S3.2.

The invention is not limited to the exemplary embodiments shown here.

Rather, the scope of protection is defined by the patent claims.

Reference character list

1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 sheet metal

2.1, 2.2 airplane

3 wings

4 hull

5.1 , 5.2, 5.3, 5.4 normal range

6.1, 6.2, 6.3, 6.4 first surface milling area

7 second surface milling area

8 sheet edge

9 bending edge

10 recess

11 machine table

12.1, 12.2, 12.3 mold

13 other workpiece

14.1, 14.2, 14.3 fixing part

15 first cover mat

16 second cover mat

17 partial cover mat

A - A’ Section through sheet metal 1.1

B - B' Section through sheet metal 1.4 a Distance sheet edge - first surface milling area b.1 sheet thickness in the normal area of sheet metal 1.1 b.4 sheet thickness in the normal area of sheet metal 1.4 c.1 sheet thickness in the first surface milling area of sheet metal 1.1 c.4 sheet thickness in the first surface milling area of Sheet metal 1 .4 d distance bending edge - first surface milling area e distance recess - first surface milling area f sheet thickness in the second surface milling area of sheet metal 1.4

P1 surface milling process

P2 forming process

51 table assembly step

52 capping step

53 pressing step

51 .1 Mold Positioning Sub-Step

51 .2 Sheet metal positioning substep

51.3 fixation substep

52.1 first full coverage substep

52.2 second full coverage sub-step

52.3 Partial coverage substep

53.1 break-in sub-step

53.2 Fluidpress substep

Claims

patent claims

1 . Aircraft component, wherein the aircraft component comprises a panel (1.1, 1.2, 1.3, 1.4, 1.5, 1.6), characterized in that the panel (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) has a normal area (5.1, 5.2, 5.3, 5.4) and a first surface milling area (6.1, 6.2, 6.3, 6.4), wherein a sheet metal thickness (b.1, b.4) of the sheet metal (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) in the normal area (5.1, 5.2, 5.3, 5.4) is greater than a sheet thickness (c.1, c.4) of the sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1 .6) in the first surface milling area (6.1, 6.2, 6.3, 6.4).

2. Aircraft component according to claim 1, characterized in that the aircraft component is an aircraft component.

3. Aircraft component according to one of the preceding claims, characterized in that a distance (a) between a sheet metal edge (8) and the first surface milling area (6.1, 6.2, 6.3, 6.4) is at least 10 cm, preferably at least 5 cm, particularly preferably at least 3 cm.

4. Aircraft component according to one of the preceding claims, characterized in that a distance (d) between a bending edge (9) and the first surface milling area (6.1, 6.2, 6.3, 6.4) is at least 3 cm, preferably at least 2 cm, particularly preferably at least 1 cm.

5. Aircraft component according to one of the preceding claims, characterized in that the metal sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) comprises a recess (10), with a distance (e) between the recess (10) and

24 the first surface milling area (6.1, 6.2, 6.3, 6.4) is at least 3 cm, preferably at least 2 cm, particularly preferably at least 1 cm.

6. Aircraft component according to one of claims 2 to 5, characterized in that the aircraft component is a wing element or an outer skin element or a frame element or a stringer element or a rib element or a cover element or another element.

7. Aircraft component according to one of the preceding claims, characterized in that the metal sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) is a light metal sheet, the light metal sheet preferably consisting of aluminum or an aluminum alloy.

8. Aircraft component according to one of the preceding claims, characterized in that the sheet metal (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) comprises a second surface milling area (7), wherein a sheet metal thickness (f) of the sheet metal (1.1, 1.2, 1.3 , 1 .4, 1 .5, 1 .6) in the second surface milling area (7) is smaller than the sheet thickness (c.1, c.4) of the sheet (1.1, 1.2, 1 .3, 1 .4, 1 .5, 1.6) in the first surface milling area (6.1, 6.2, 6.3, 6.4).

9. Aircraft component according to claim 8, characterized in that the sheet metal (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) comprises a further surface milling area, with a sheet metal thickness of the sheet metal (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) in the further surface milling area is smaller than the sheet metal thickness (f) of the sheet metal (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) in the second surface milling area (7).

10. Aircraft comprising an aircraft component according to one of the preceding claims, wherein the aircraft is preferably an airplane (2.1, 2.2).

11. Aircraft according to claim 10, comprising a plurality of aircraft components according to one of the preceding claims, the plurality of aircraft components preferably having at least one wing element and/or an outer skin element and/or a frame element and/or a stringer element and/or a rib element and/or a covering element and/or another element.

12. Method for producing an aircraft component according to one of claims 1 to 9, characterized in that the method comprises a surface milling process (P1), in the context of which material is removed from a sheet metal blank in such a way that the sheet metal (1.1, 1.2, 1.3, 1.4 , 1.5, 1.6, 1.7, 1.8) with the normal area (5.1, 5.2, 5.3, 5.4) and the first surface milling area (6.1, 6.2, 6.3, 6.4).

13. The method according to claim 12, characterized in that the method comprises a forming process (P2), during which the sheet metal (1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8) is formed, preferably by means of fluid pressing, wherein the forming process (P2) is carried out after the surface milling process (P1).

14. The method according to claim 13, characterized in that the forming process (P2) comprises a table assembly step (S1), a covering step (S2) and a pressing step (S3).

15. The method according to claim 14, characterized in that the table assembly step (S1) comprises the following:

- A mold positioning sub-step (S1.1), in the context of which on a machine table (11) of a metalworking machine, preferably one

Fluid cell press, a mold (12.1, 12.2, 12.3) is positioned, and - A sheet metal positioning step (S1 .2) in which the sheet metal (1.1, 1.2, 1 .3, 1.4, 1.5, 1.6, 1.7, 1.8) is positioned on the forming tool (12.1, 12.2, 12.3), and

- Preferably a fixing sub-step (S1.3), during which the metal sheet (1.1, 1.2,

1.3, 1.4, 1.5, 1.6, 1.7, 1.8) is fixed on the mold (12.1, 12.2, 12.3), preferably with the aid of a fixing part (14.1, 14.2, 14.3) and/or with the aid of at least one fixing pin.

16. The method according to claim 15, characterized in that the covering step (S2) comprises:

- A first complete covering partial step (S2.1), in the context of which a first covering mat (15) is placed on all molds (12.1, 12.2, 12.3) and the metal sheets (1.1, 1.2, 1.3, 1.4, 1.5, 1.6) positioned on them 1.7, 1.8) is placed so that the first covering mat (15) covers all the forming tools (12.1, 12.2, 12.3) and the metal sheets (1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8) positioned on them, and

- preferably a second complete covering partial step (S2.2), during which a second covering mat (16) is placed on the first covering mat (15), so that the second covering mat (16) covers the first covering mat (15), and

- preferably a partial covering partial step (S2.3), in the context of which a partial covering mat (17) is positioned on at least one combination of mold (12.1, 12.2, 12.3) and sheet metal (1.1, 1.2 , 1.3,

1.4, 1.5, 1.6, 1.7, 1.8) is placed so that the partial covering mat (17) is the combination of the mold (12.1, 12.2, 12.3) and the metal sheet (1.1, 1.2, 1.3) positioned on the mold (12.1, 12.2, 12.3). , 1.4, 1.5, 1.6, 1.7, 1.8), the partial coverage sub-step (S2.3) preferably being carried out before the first complete coverage sub-step (S2.1).

17. The method according to any one of claims 15 to 16, characterized in that the pressing step (S3) comprises:

27 - A retraction sub-step (S3.1), in the context of which the machine table is equipped

(11) is moved into a pressing area, and

- A fluid press sub-step (S3.2), during which the equipped machine table (11) is subjected to an oil pressure in the pressing area, so that the metal sheet (1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8) is transformed.

18. Aircraft component according to one of claims 1 to 9, characterized in that the aircraft component is generated using a method according to one of claims 12 to 17.

19. Aircraft comprising an aircraft component according to claim 18, wherein the aircraft is preferably an airplane (2.1, 2.2).

28