Abstract:
The present invention pertains inter alia to a method for producing a component for connecting structures at crossing regions thereof, having the following steps: depositing first and second fibers on an underlay in such a way that a respective first fiber has an offset in the longitudinal direction of the first or second fiber with respect to a respective second fiber; connecting the first and second fiber along an overlap region, in which the first and second fibers overlap; and pivoting the first and second fibers with respect to one another to form the component.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Application No. 61/552,732, filed on Oct. 28, 2011, and of German patent application No. 10 2011 084 438.4, filed Oct. 13, 2011, the entire disclosures of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method for producing a component for connecting structures, a method for producing a structural arrangement and a device for producing a component. 
       FIG. 1  shows a detail from an aircraft designated  100  in general. The aircraft  100  comprises a landing flap  102 .  FIG. 1  shows the landing flap  102  counter to the flight direction of the aircraft  100 . The landing flap  102  is shown once in a dashed view, which corresponds to its unloaded state. The landing flap  102  is furthermore shown by a continuous line, which corresponds to its state shown greatly exaggerated and deformed because of air loads  104 . The landing flap  102  is connected by means of two flap carriages  106 ,  108  to a wing  110 , which is only schematically indicated. The flap carriages  106 ,  108  allow an adjustment of the landing flap  102  with respect to the wing  110  from a flight position into a take-off or landing position, the take-off and landing position serving to increase the lift. In the wingspan direction, in other words from left to right in  FIG. 1 , one flap carriage  106  is configured as a fixed bearing and the other flap carriage  108  as a loose bearing. The flap carriages  106 ,  108  are in each case connected by an eye-pin connection  112  to the landing flap  102 . 
     It is known to configure the eye of a respective eye-pin connection  112  in the form of a fitting, which is manufactured from metal and is connected, in particular riveted, to the landing flap  102 . For example, DE 10 2007 011 613 A1 shows a fitting made of metal for load introduction. 
     There is increasingly a need to also produce load introduction elements, such as, for example, the above-described eye of the eye-pin connection  112 , from fibre composite materials, for example carbon fibre plastics material (CFRP), in order to save further weight and assembly costs. US 2010/0148008 A1 describes a corresponding load introduction element made of fibre composite material, which is produced by an RTM (resin transfer moulding) method. 
     SUMMARY OF THE INVENTION 
     An idea of the present invention is to disclose a method for simple production of a component, in particular the load introduction element described above, a method for simple production of a structural arrangement and a device for simple production of the component. 
     Accordingly, a method is provided for producing a component for connecting structures at crossing regions thereof, having the following steps: depositing first and second fibres on an underlay, in such a way that a respective first fibre has an offset in the longitudinal direction of the first or second fibre with respect to a respective second fibre, connecting the first and second fibre along an overlap region, in which the first and second fibres overlap, and pivoting the first and second fibres with respect to one another to form the component. 
     Furthermore, a method is provided for producing a structural arrangement, in particular for an aircraft or spacecraft, having the following steps: providing a first structure, providing a second structure, which forms a crossing region with the first structure, producing a component by the method according to the invention and connecting the first and second structure in the crossing region by means of the component. 
     Furthermore, a device is provided for producing a component for connecting structures at crossing regions thereof, in particular for carrying out the method according to the invention, with an underlay, a depositing mechanism to deposit the first and second fibres on the underlay, in that a respective first fibre has an offset in the longitudinal direction of the first or second fibre with respect to a respective second fibre, a connecting mechanism to connect the first and second fibres along an overlap region, in which the first and second fibres overlap, and a pivoting mechanism for pivoting the first and second fibres with respect to one another to form the component. 
     The idea on which the present invention is based on the finding that a component with an approximately cruciform cross-section can easily be produced, in which the first and second fibres are pivoted relative to one another. After the pivoting, the first fibres intersect with the second fibres at a crossing point. The first fibres then extend, for example, substantially horizontally through the crossing point and the second fibres extend, for example, substantially perpendicularly. If the component thus provided is integrated in a structural arrangement, in particular in the landing flap described at the outset, the latter can provide two substantially mutually independent load paths through the crossing point: the first load path leads along the first fibres and the second load path leads along the second fibres. 
     The use of the methods and the device is not restricted to the field of air or space travel. For example, these may also be used in the area of producing bridges, multi-storey buildings, masts, roofs or other planar supporting structures. 
     “Fibre” preferably comprises both a single fibre and a fibre tow of individual fibres. 
     Advantageous configurations of the invention emerge from the subordinate claims. 
     The first and second fibres are preferably deposited parallel to one another on the underlay. If, in the present case, “parallel” is referred to, deviations from this of up to 30 degrees, preferably up to 10 degrees, still more preferably up to 2 degrees, are also meant. 
     According to a preferred configuration of the method according to the invention, it is provided that the first fibres are connected to one another in a first projection region, in which they project in the longitudinal direction over the second fibres, and/or the second fibres are connected to one another in a second projection region, in which they project in the longitudinal direction over the first fibres. This produces a stable structure of first fibres, which can be pivoted against a second structure made of second fibres. 
     According to a preferred configuration of the method according to the invention, it is provided that the first and second fibres are connected to one another in the overlap region along a centre line, which is arranged centrally in relation to a total extent of the first and second fibres in the longitudinal direction, and/or the first fibres are connected to one another in the first projection region along a first line parallel to the centre line and/or the second fibres are connected to one another along a second line parallel to the centre line and opposing the first line in relation to the centre line. This type of fastening of the fibres can be produced easily, in particular in an automated manner, because it is substantially linear. 
     According to a preferred configuration of the method according to the invention, it is provided that the first and second fibres are connected to one another in the overlap region, the first fibres are connected to one another in the first projection region and/or the second fibres are connected to one another in the second projection region by means of stitching, weaving, braiding or gluing. The stitching, weaving, braiding and gluing can easily be automated. 
     According to a preferred configuration of the method according to the invention, it is provided that at least one stitching, weaving or braiding fibre is fed through a gap in the underlay. For example, a lower fibre (“bottom thread”) can thus easily be fed. 
     According to a preferred configuration of the method according to the invention, it is provided that the gluing takes place by means of a thermoplastic strand, a fibre sheathed at least in portions with a thermoplastic material, or an adhesive strip. The thermoplastic strand, the fibre and the adhesive strip may, for example, be easily laid along the first or second line and/or the centre line in order to thereby glue them to the first and/or second fibre. 
     According to a preferred configuration of the method according to the invention, it is provided that the first and second fibres are pivoted with respect to one another in such a way that the latter have an angle of 30 to 90 degrees, preferably 60 to 90 degrees, more preferably 80 to 90 degrees, still more preferably 90 degrees, with respect to one another, and/or the pivoting of the first and second fibres with respect to one another is brought about by means of a curved guide element, past which the first and/or second fibres are guided. As a result, the component can easily be produced with a cruciform cross-section. 
     According to a preferred configuration of the method according to the invention, it is provided that the underlay is configured as a conveyor belt, on which the first and second fibres are deposited. By means of the conveyor belt, the first and second fibres can move past the connecting mechanism in an automated manner, so an efficient method is ensured. 
     According to a preferred configuration of the method according to the invention, it is provided that the first and second fibres are in each case cut to length from continuous material before the depositing. As a result, the efficiency of the method can also be increased. 
     According to a preferred configuration of the device according to the invention, it is provided that the underlay has a plurality of parts, which, between them, define at least one gap, through which at least one stitching, weaving or braiding fibre can be fed to connect the first and/or the second fibre. 
     According to a preferred configuration of the device according to the invention, it is provided that the connecting mechanism is set up to connect the first fibres to one another in a first projection region, in which they project in the longitudinal direction over the second fibres, and/or to connect the second fibres to one another in a second projection region, in which they project in the longitudinal direction over the first fibres. For this purpose, the connecting mechanism may be guided, in particular, by a robot hand. 
     According to a preferred configuration of the device according to the invention, it is provided that the connecting mechanism comprises at least one stitching needle, by means of which the first fibres, second fibres and/or the first and second fibres can be stitched to one another. 
     According to a preferred configuration of the device according to the invention, it is provided that the pivoting mechanism has a curved guide path to guide the first and/or second fibre past and to pivot them. The guide path is, in particular, configured as a guide rail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in more detail below on the basis of embodiments with reference to the accompanying figures of the drawings, in which: 
         FIG. 1  shows a detail of an aircraft; 
         FIG. 2  shows a schematic view of a structural arrangement comprising a component; 
         FIG. 3  shows a perspective view of a device for producing the component from  FIG. 2  in a first state; 
         FIG. 4  shows the view from  FIG. 3  in a second state of the device; 
         FIG. 5  shows the view from  FIG. 4  in a third state of the device; 
         FIG. 6  shows a section through a thermoplastic strand; 
         FIG. 7  shows a section through a fibre sheathed with a thermoplastic material; and 
         FIG. 8  shows a section through an adhesive strip. 
     
    
    
     Identical reference numerals in the figures denote identical or functionally identical components, unless indicated otherwise. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 2  shows a partially perspective view of a structural arrangement  200  according to an embodiment kept comparatively general. 
     The structural arrangement  200  is, for example, a component of the landing flap  102  shown in  FIG. 1  and therefore a component of the aircraft  100 . Basically, the structural arrangement  200  may, however, be a component of any flap or aerofoil wing. 
     In the present case, the three spatial directions that are orthogonal to one another are designated X, Y and Z. This serves merely for better understanding of the spatial arrangement of the various components with respect to one another. In the case of the landing flap  102 , X designates the oncoming flow direction, Y the wingspan direction and Z the vertical direction. 
     The structural arrangement  200  comprises a substantially closed box structure  202  indicated by dashed lines in  FIG. 2 . By “substantially closed” it is meant that the box structure  202  has no or only comparatively small apertures in its outer walls  204 . The front outer wall  206  is shown as transparent in  FIG. 2  to reveal the view of the interior  208  of the box structure  202 . The outer walls  204 ,  206 , according to one embodiment, form the outer skin of the landing flap  102 . 
     The structural arrangement  200  furthermore comprises a component  210 , which is composed of first and second fibres  212 ,  214 , wherein, for the sake of better understanding, only one such individual first fibre  212  and an individual second such fibre  214  are shown in the YZ-plane. The component  210  may comprise any desired number of such fibres  212  and  214  arranged next to one another in the X-direction. The first and second fibres  212 ,  214  are designated by short dashes in opposing directions to distinguish them better. A respective first fibre  212  extends, for example, in a horizontal XY-plane, while a respective second fibre  214  extends, for example, in a vertical XZ-plane. A respective first fibre  212  and a respective second fibre  214  therefore extend, according to the embodiment, perpendicular to one another. 
     A respective first fibre  212  and a respective second fibre  214  are connected to one another at a crossing point  216 . The fibres  212 ,  214  are stitched, woven, braided or glued to one another at the crossing point  216 . It is furthermore shown in  FIG. 2  that a respective first fibre  212  has a first and second portion  218 ,  220 , the portions  218 ,  220  being connected to the lower outer wall  204 , which extends in the XY-plane, of the box structure  202 . Stated more precisely, the first portion  218  of the first fibre  212  is integrated in a first portion  232  of the outer wall  204  and the second portion  220  of the first fibre  212  is integrated in a second portion  233  of the outer wall  204 , in particular glued in. For this purpose, the portions  232 ,  233  of the outer wall  204  are in each case fork-shaped. However, a different type of fastening of the portions  218 ,  220  on or in the outer wall  204  of the box structure  202  is also conceivable. 
     A respective second fibre  214  forms an inner web  222 , which projects upwardly into the interior  208  of the box structure  202 , and an outer web  224 , which extends downwardly outside the box structure  202 . The inner web  222  is connected to a support element  234  of the structural arrangement  200 . The support element  234  is, for example, configured as a rib, which is connected to the box structure  202 . The support element  234  may, for example, also be configured as a beam or transverse web. The inner web  222  is preferably integrated in the support element  234 , in particular glued in. 
     The outer web  224  has a fastening point  226  to introduce a first load  230  into the outer web  224 . The fastening point  226  is, in particular, configured as an eye, but may also be configured as a different structural load transmission device, such as, for example, a riveting or gluing. A corresponding axis of the eye  226  is designated by the reference numeral  228 . 
     The second fibre  214  guides the first load  230  introduced at the fastening point  226  from the fastening point  226  into the support element  234 . The first fibre  212  simultaneously transmits the second load  235  between the first and second portions  232 ,  233  of the box structure  202 . Therefore, two substantially mutually independent load paths are provided. For example, bending loads  235  in the outer wall  204  are guided by means of the first fibres  212  through the crossing point  216 , while—substantially unaffected thereby—the holding forces  230  introduced at the eye  226  by means of the flap carriage  106 ,  108  are guided into the support element  234 . Despite the fibre composite mode of construction, the eye  226  is therefore effectively prevented from peeling off in the coupling region  216  by the uninterrupted first and second fibres  212 ,  214 . 
     The outer wall  204 , with the rib  234 , forms a crossing region  236 , in which the component  210  is preferably glued. The gluing of the portions  218 ,  220  of the component  210  in the outer wall  204  of the box structure  202  may take place in different ways: the completely or partially cured portions  218 ,  220  can be cured with the wet outer wall  204 . Furthermore, the completely or partially cured portions  218 ,  220  can be structurally glued to the completely or partially cured outer wall  204 . Furthermore, the dry portions  218 ,  220  can be infiltrated together with the dry outer wall  204  and cured. Furthermore, the wet portions  218 ,  220  (prepregs) can be glued to the wet outer wall  204  (prepreg). 
     Furthermore, the inner web  222  of the component  210  is preferably also glued into the rib  234  (or a beam or transverse web) in one of the ways as described above for the portions  218 ,  220 . The outer web  226  can also be glued into a rib, not shown. 
     Other possibilities of connecting the component  210  to the outer wall  204  and rib  234  are conceivable, for example bolting or screwing. 
       FIG. 3 to 5  show a plurality of states when producing the component  210  from  FIG. 2  by a stitching method. Furthermore,  FIG. 3 to 5  show various components of a device  300  for carrying out the method. 
     First and second fibres  212 ,  214  are deposited parallel to one another on a conveyor belt  302 , moving in the conveying direction F, of the device  300 , see  FIG. 3 . A respective fibre  212 ,  214  is preferably configured as a “fibre tow” of individual fibres. The designations 2k to 24k are, for example, prevalent here. A respective fibre  212 ,  214  is preferably deposited dry, i.e. without a thermoplastic or thermosetting matrix, although a depositing of wet fibres  212 ,  214  is in no way ruled out. 
     The device  300  furthermore comprises a reel  301  with continuous material  303 , a cutting mechanism  305  and a depositing mechanism  304 . The fibres  212 ,  214  are cut to length from the continuous material  303  by means of the cutting mechanism  305  and thereafter deposited on the conveyor belt  302  by means of the depositing mechanism  304 , in particular a robot. 
     The fibres  212 ,  214  preferably in each case have the same length and, after depositing, extend in the direction  306  transverse to the conveying direction F. 
     The transverse direction  306  therefore corresponds to the longitudinal direction of the fibres  212 ,  214 . The deposited fibres  212 ,  214  in each case have an offset  308  in the transverse direction  306  with respect to one another. This produces a first and second projection region  310 ,  312 . The first projection region  310  only has ends of the first fibres  212  and the second projection region  312  only has ends of the second fibres  214 . 
       FIG. 4  shows how the ends of the first fibres  212  are stitched together in the projection region  310 . A corresponding connecting mechanism of the device  300  comprises a needle  400  and a stitching fibre  402 . The stitching takes place, for example, along a line  404 . Moreover, the ends of the second fibres  214  are stitched together in the second projection region  312 . A corresponding connecting mechanism of the device  300  comprises a needle  406  and a stitching fibre  408 . The stitching takes place, for example, along a line  410 . 
     Between the two projection regions  310 ,  312 , the first and second fibres  212 ,  214  form an overlap region  412 , in which they overlap in the transverse direction  306 . The first and second fibres  212 ,  214  are stitched together in the overlap region  412 , in particular along a centre line  414 . The centre line  414  is arranged centrally in relation to a total extent  416  of the fibres  212 ,  214  in the transverse direction  306 . A corresponding connecting mechanism in the form of a needle and a stitching fibre is designated by the reference numerals  418  and  420 . The lines  404 ,  410 ,  414  are preferably parallel to one another. 
     The movement of the needles  400 ,  406 ,  418  is indicated in each case by a double arrow. A respective upper stitching fibre  402 ,  408 ,  420  (“top thread”) is preferably connected to a corresponding lower stitching fibre  421 ,  423 ,  425  (“bottom thread”). For this purpose, the conveyor belt  302  is preferably formed from a plurality of parts  422 ,  424 ,  426 ,  428 , which form gaps  430 ,  432 ,  434  between them, through which a respective lower stitching thread  421 ,  423 ,  425  can easily be fed. 
     After this, the second fibres  214  are pivoted relative to the first fibres  212  about the centre line  414 , i.e. about the stitching fibre  420 , as indicated by the arrows in  FIG. 5 . A respective first fibre  212  then preferably forms, with a respective second fibre  214 , an angle  500  of 90 degrees. A component  210  is therefore formed, which thereafter is integrated in the crossing region  236  of the structural arrangement  200 , see  FIG. 2 , in particular as described above. The pivoting takes place, for example, by means of a pivoting mechanism of the device  300  in the form of a curved guide rail  501 , which gradually rotates the second fibres  214  relative to the first fibres  212 . The first fibres  212  may, for example, be moved onwards supported on horizontal guide rails  502  of the device  300 , while the second fibres  214  pivot. The guide rails  500 ,  502  are only shown partially for the sake of greater clarity. For rotation, the first and second fibres  212 ,  214  can be lifted from the conveyor belt  302 , which is why this is not shown in  FIG. 5 . 
     Instead of stitching, the first and second fibres  212 ,  214  can be woven or braided together by means of fibres  402 ,  408 ,  420 . 
     The first and second fibres  212 ,  214  can furthermore alternatively be glued to one another, in particular by means of a thermoplastic strand  600  (see  FIG. 6 ), a fibre  702  sheathed with thermoplastic material  700  (see  FIG. 7 ) or an adhesive strip  800  (see  FIG. 8 ).  FIG. 6 to 8  show a cross-sectional view, in each case. 
     In an embodiment which is not shown, a first thermoplastic strand, a first sheathed fibre or a first adhesive strip extends along the first line  404  and connects the first fibres  212 . A second thermoplastic strand, a second sheathed fibre or a second adhesive strip extends, for example, along the second line  410  and connects the second fibres  214 . A third thermoplastic strand, a third sheathed fibre or a third adhesive strip extends, for example, along the centre line  414  and connects the first and second fibres  212 ,  214  to one another. 
     Although the invention was described in the present case with the aid of preferred embodiments, it is not in any way restricted thereto, but can be modified in diverse ways. In particular, the embodiments and configurations described for the methods according to the invention can be applied accordingly to the device according to the invention, and vice versa. Furthermore, “a” does not rule out a plural in the present case.