Doctor's stamp

Abstract

A laying die 10 for the automated positioning of a fiber mat piece 12 on a curved target surface 14 comprises: a connecting element 16 for connecting the laying die 10 to a robot arm 13, a rigid base 18 attached to the connecting element 16, an elastically deformable carrier body 20 provided on a distal side 18d of the base 18, an elastically deformable receiving structure 22 fastened to a distal side 20d of the carrier body 20 for receiving and holding the fiber mat piece 12 on a contact surface 23, and a device 23 for generating an adjustable volume flow at the contact surface 23, wherein the receiving structure 22 comprises a network 26 constructed from filaments 24 or filament bundles, which forms the contact surface 23.

Description

[0001] The present invention relates to a laying die having the features of the preamble of claim 1 for the automated positioning of a fiber mat piece on a curved target surface.

[0002] Such a generic laying die, as known for example from the documents EP 2796263 A2 or WO 2018162637 A1, comprises a connecting element for connecting the laying die to a robot arm, a rigid base attached to the connecting element, preferably in the form of a base plate, an elastically deformable carrier body provided on a distal side of the base, an elastically deformable receiving structure fastened on a distal side of the carrier body for receiving and holding the fiber mat piece on a contact surface of the receiving structure, and a device for generating an adjustable volume flow at the contact surface.

[0003] The fiber mat pieces are material cuts for the construction of a component with polymer components, cut e.g. from fiber-reinforced fabrics, adhesive films or similar.

[0004] Such laying dies are used to produce complex-shaped three-dimensional components made of fiber-reinforced composite materials, whereby previously cut pieces of fiber mat are automatically sucked in with the help of the laying die and moved to a desired position on the surface of a mold.

[0005] Due to the elastic deformability of the carrier body and the receiving structure, the piece of fiber mat held on the contact surface of the receiving structure can be positioned at a desired location on a curved target surface with high precision and pressed onto the target surface.

[0006] In the case of state-of-the-art laying stamps, the contact surface is formed, for example, by elastically deformable foils, e.g. made of silicone, which are provided with holes for distributing the volume flow or negative pressure.

[0007] In practice, it has been shown that when positioning with the known laying stamps, it can still happen that the piece of fiber mat does not lie flat on the target surface everywhere, but that small folds form in the piece of fiber mat positioned on the target surface, especially in places of particularly strong convex curvature.

[0008] Against this background, the object of the present invention is to improve the known laying die in such a way that the surface quality of the components that can be produced with the aid of the laying die is improved.

[0009] This object is achieved by a laying stamp having the features of claim 1. Specific embodiments of the invention are described in the dependent claims.

[0010] According to the invention, it is proposed that the receiving structure comprises a network constructed from filaments or filament bundles, which forms the contact surface.

[0011] It is assumed that the contact surface of the receiving structure in the state-of-the-art stamps itself wrinkles heavily when adapting to strongly convex curved areas of the target surface and that the fiber mat piece forms the observed surface defects due to its adhesion to the contact surface.

[0012] By using a network constructed from filaments or filament bundles to form the contact surface, the flexural rigidity of the receiving structure can be increased compared to the film used for this purpose in the prior art, which reduces the formation of wrinkles on the contact surface.

[0013] On the other hand, the reduced surface contact between the piece of fiber mat and the contact surface formed by a net according to the invention due to the mesh compared to a film makes it possible for the piece of fiber mat to specifically deflect or slide in a specific direction, namely perpendicular to the curvature or bending axis, at points of strong convex curvature of the target surface and thus strong bending of the net relative to the contact surface, which also reduces the risk of wrinkling of the piece of fiber mat.

[0014] In this sense, the mesh provided according to the invention forms a contact surface with non-stick properties for areas of strong curvature.

[0015] The network can be constructed from individual filaments and / or filament bundles, whereby the filaments of a bundle can run parallel to each other or be twisted together.

[0016] Depending on the application, the filaments or filament bundles may comprise or be formed from a plastic with or without fiber reinforcement, preferably a thermoplastic, which is particularly preferably selected from polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyoxymethylene (POM) or a mixture thereof.

[0017] To modify the adhesion properties, the filaments can be coated individually or as a whole with an additional material to reduce adhesion.

[0018] A thickness of the filaments or filament bundles of the mesh may be in the range between 0.1 mm and 3 mm, preferably between 0.2 mm and 1.5 mm and particularly preferably between 0.5 mm and 1 mm, wherein the boundary values ​​of the specified intervals are included in each case.

[0019] The mesh can be formed by any technique, for example by weaving, braiding, knitting or knitting, or by directly joining the filaments or filament bundles at the contact or crossing points, for example by gluing or welding.

[0020] For better adaptability to the target surface, the net may not be fixed to the carrier body over its entire surface. For example, the laying die may comprise a frame, e.g., made of an elastomeric material, which is attached to the carrier body and holds the frame at its outer periphery, with the net being attached to the carrier body at most at specific points and / or along predetermined lines within the frame. Preferably, the net is not attached to the carrier body at all within the frame.

[0021] Particularly in the case of larger laying stamps, it can be provided that the net is divided into several net sections, each of which is fastened or held on its outer circumference to a net section frame, wherein the individual net section frames are fastened to the carrier body and the net within the net section frames is fastened to the carrier body at most at certain points and / or along individual lines and is preferably not fastened to the carrier body at all.

[0022] Depending on the application, a heating device can be provided between the net and the carrier body.

[0023] In practice, the target surface is often curved only or primarily around a single principal curvature axis. Since the robot arm allows the placement die to be aligned to a predetermined placement position on the target surface according to the principal curvature axis, it is therefore advisable to design the die for a deformation that corresponds to a curvature of the carrier body and the receiving structure only or primarily around a single axis.

[0024] For this purpose, it can be provided, for example, that only those filaments or filament bundles of the mesh that extend essentially perpendicular to a first predetermined direction contribute to the contact surface. The laying die is then to be aligned so that the first predetermined direction runs parallel to the main axis of curvature of the target surface at the location where the fiber mat piece is to be deposited. Such texturing of the mesh surface allows it to act like a guide rail, along which the fiber mat piece can slide perpendicular to the predetermined first direction while adapting to the target surface, thus reducing the risk of wrinkling.

[0025] Structurally, such texturing can be achieved through a suitable manufacturing technique, such as weaving. An alternative manufacturing technique involves positioning two layers of parallel linear filaments on top of each other to form a mesh, and connecting the filaments of the two layers at their intersection points, e.g., by gluing or welding.

[0026] In practice, it is often desirable to place elongated pieces of fiber mat in such a way that their longitudinal direction is perpendicular to the main axis of curvature of the target surface at the deposition point.

[0027] The direction referred to in this application as the "first predetermined direction" therefore always preferably corresponds to the transverse direction of a laying die whose contact surface is longer in the longitudinal direction than in the transverse direction. Preferably, a dimension of the contact surface in the longitudinal direction is at least twice as large as a dimension of the contact surface in the transverse direction.

[0028] In order to reduce the risk of uncontrolled wrinkling of the contact surface when adapting to the target surface, it can further be provided that a flexural rigidity of the net for a bend about a first axis parallel to a first predetermined direction (i.e. in particular for a bend about a bending axis running in the transverse direction of the laying die) is greater than for a bend about a second axis perpendicular to the first predetermined direction (i.e. in particular for a bend about an axis running in the longitudinal direction of the laying die), wherein the flexural rigidity for a bend about the first axis can preferably be two to five times the flexural rigidity for a bend about the second axis.

[0029] In other words, the network can consist of longitudinal filaments and transverse filaments, with the transverse filaments being less stiff than the longitudinal filaments.

[0030] Again, when depositing the fiber mat piece, the first direction preferably runs parallel to the main axis of curvature of the target surface at the location where the fiber mat piece is to be deposited.

[0031] This different bending stiffness of the mesh in two directions can be achieved in different ways.

[0032] For example, the filaments or filament bundles that extend substantially perpendicular to the first direction and thus in particular along the longitudinal direction of the stamp can be thicker than all other filaments or filament bundles. In particular, the diameter of the filaments or filament bundles that extend perpendicular to the first direction can be at least twice as large as the diameter of the filaments or filament bundles that extend not perpendicularly, but in particular parallel to the first predetermined direction.

[0033] Alternatively or additionally, for the same purpose, it may be provided that the net comprises more filaments or filament bundles extending substantially perpendicular to the first direction than filaments or filament bundles extending not perpendicular to the first direction and in particular parallel to the first direction, for example twice as many.

[0034] The material of the filaments extending parallel and perpendicular to the first direction can also be selected accordingly. In particular, it can be provided that only those filaments extending substantially perpendicular to the first direction, i.e., in particular, only the longitudinal filaments, have fiber reinforcement.

[0035] In principle, however, for better draping properties of the net, it can also be provided that the net is formed from two groups of filaments or filament bundles, wherein the filaments or filament bundles of the first group extend at an angle of approximately + 45° to a longitudinal direction of the contact surface or the laying die, and the filaments or filament bundles of the second group extend at an angle of approximately - 45° to the longitudinal direction, i.e. the net is cut in the oblique thread path.

[0036] Two methods have emerged in the state of the art for positioning a piece of fiber mat on a convexly curved target surface using a placement die. Firstly, the placement die can be positioned preferably symmetrically to and above a vertex of the curvature and pressed onto it in a straight line, a process known as "direct push-in." This process is quite fast but only suitable for relatively simple target surface geometries.

[0037] It can also happen with strongly curved surfaces that the deformability of the laying die is exceeded, so that the pressing of the fiber mat piece does not take place over the entire length of the die, but only locally, whereby areas of the fiber mat piece are then not pressed at all and therefore not laid down in a defined manner.

[0038] In this case, in an alternative method, the laying die can initially be positioned only on one side of the apex and the piece of fiber mat can be pressed on this side, after which the laying die is rotated around the apex in a kind of rolling movement in order to also press the piece of fiber mat on the other side of the apex.

[0039] However, this process is relatively time-consuming and requires a robot arm with 6 degrees of freedom and, under certain circumstances, a targeted control of the volume flow in different areas of the contact surface.

[0040] Therefore, according to a preferred development of the invention, it is proposed that the laying die further comprises an articulated plate with at least one plate pair consisting of two rigid plate sections coupled to one another so as to be rotatable about a pivot axis, and at least one actuator assigned to the plate pair, wherein the actuator is fastened to the base and is designed to change a pivot angle between the two rigid plate sections of the plate pair, and wherein the carrier body is fastened to a distal side of the articulated plate in such a way that the carrier body and the receiving structure are elastically deformable by changing the pivot angle.

[0041] By adjusting the swivel angle, for example, a pre-deformation can be achieved before the pre-deformed laying stamp with the piece of fiber mat adhering to the contact surface is pressed onto the target surface.

[0042] Preferably, the pivot axis runs in the transverse direction of the laying die.

[0043] With the foils known from the prior art as a receiving structure for the piece of fiber mat, such a construction would result in significant creases at the location of the receiving structure opposite the pivot axis, which can, however, be avoided or at least significantly reduced by the net structure provided according to the invention.

[0044] It is noted that terms such as proximal and distal, unless otherwise stated, refer in this application to the robot arm, i.e., a proximal side or surface of a component is the one facing the robot arm, while the distal side or surface of the component is facing away from the robot arm.

[0045] Preferably, the articulated plate comprises a plurality of plate pairs, each consisting of two rigid plate sections rotatably coupled to one another about a pivot axis, wherein the pivot axes of the plurality of plate pairs all run parallel to one another, and wherein the laying die for each plate pair comprises at least one actuator associated with the plate pair, which actuator is attached to the base plate and is configured to change a pivot angle between the two rigid plate sections of the respective plate pair. In particular, the pivot angles of the different plate pairs can be adjusted independently of one another to enable adaptation to target surfaces with more complex geometries.

[0046] For example, the joint plate may comprise three plate sections arranged in a row, of which the middle one is immovably attached to the base and is pivotally connected to each of the two outer plate sections by a hinge, wherein two actuators are provided to pivot the two outer plate sections relative to the middle plate section about the respectively associated pivot axis.

[0047] Preferably, the pivot axis or the pivot axes of the laying die run parallel to the first predetermined direction explained above or in the transverse direction of the laying die.

[0048] Based on the present disclosure, the applicant reserves the right to protect an actively deformable laying die with the features of the preamble of original claim 1 of the present application and the additional features of original claim 12, even without the features of the characterizing part of original claim 1, i.e., regardless of the specific design of the receiving structure. Preferably, such a laying die can also have the additional features of original claim 13 and / or any other of the above-described additional features of the possible developments of a laying die with an articulated plate.

[0049] The present invention will be explained in more detail below using selected embodiments, which are illustrated in the accompanying figures. Fig. 1 shows a simplified representation of a laying die according to a first embodiment of the invention, wherein the partial figures a) to c) each illustrate different stages of a method for positioning a piece of fiber mat on a curved target surface with this laying die, Fig. 2 a simplified representation of a laying stamp according to a second embodiment of the invention, Fig. 3 a photograph of a prototype of the laying die according to the second embodiment, with a view of the contact surface of the laying die, Fig. 4 a photograph of the subject of Fig. 3 in use and viewed from the side, Fig. 5 a photograph of a prototype of a laying stamp according to a third embodiment, with a view of the contact surface, Fig. 6 an enlarged detail of a photograph of the laying stamp from the Fig. 3 and Fig. 4 network used, Fig. 7 a photograph of a piece of fiber mat deposited on a curved target surface using a laying die with a conventional receiving structure, u Fig. 8 a photograph of a piece of fiber mat laid on a curved target surface using a laying die according to the invention, and Fig. 9 in the partial figures a) and b) highly simplified different stages of the production of a net for the contact surface of a laying stamp according to an embodiment of the invention.

[0050] Identical or corresponding features of different embodiments are each provided with the same reference numerals, and subsequent embodiments are each described essentially only to the extent that they differ from the first embodiment, to the following description of which reference is otherwise made.

[0051] Both Fig. 1 and Fig. 2 are highly simplified and schematic representations which are essentially intended to illustrate the principle of the present invention in various embodiments and are in particular not to be understood to scale.

[0052] Fig. Figure 1 shows a laying die 10 according to a first embodiment of the present invention. This comprises a connecting element 16 for connecting the laying die 10 to a robot arm 13, only indicated here, which in turn is designed to automatically adjust and change the position and orientation of the laying die 10 in space.

[0053] A rigid base 18 is attached to the connecting element 16, here in the form of a planar base plate 19.

[0054] On a distal side 18d of the base 18, an elastically deformable support body 20 is arranged, which can preferably be made of an elastomer foam. With respect to a firmly connected to the laying die and in Fig. In the coordinate system illustrated in Figure 1, the support body has the shape of a cuboid elongated in the direction of the x-axis.

[0055] The x-direction is therefore also referred to as the longitudinal direction of the laying die, the y-direction as the transverse direction and the z-direction as the height direction.

[0056] On the underside or distal side 20d of the carrier body, a receiving structure 22 is provided, on the distal side of which, at the contact surface 23, an adjustable volume flow or negative pressure is generated by means of a device 25 (only indicated in the figures), in order to be able to suck in a fiber mat piece 12, pick it up, and hold it at the contact surface 23, as illustrated in partial figure a), in which the laying die 10 positions the fiber mat piece 12 directly above a convexly curved target surface 14, e.g., a molding tool. The device 25 can comprise a vacuum pump or a source of positively pressurized gas, wherein a volume flow suitable for sucking in the fiber mat piece 12 is generated at the contact surface, for example, as described in WO 2018162637A1.

[0057] In order to be able to specifically suction and hold the fiber mat piece 12 only at the contact surface 23, the components of the laying die 10 are designed to be airtight on the outer circumferential walls running parallel to the z-direction. Air passages from the contact surface 23 to the device 25 for generating the volume flow are provided in a known manner, but are not shown or described in detail here. Reference is also made to the corresponding disclosure in, for example, EP 2796263 A2 or WO 2018162637A1.

[0058] From the position shown in partial figure a), the laying die 10 is moved straight downwards or along the z-axis in order to place the fiber mat piece 12 on the target surface 14 and to press it down, whereby both the receiving structure 22 and the carrier body are elastically deformed, as is shown in a highly simplified manner in partial figure b).

[0059] After the volume flow has been stopped or reversed in its direction so that the fiber mat piece 12 can be released from the contact surface 23, the laying die 10 is raised again, whereby the fiber mat piece 12 remains in the desired position on the target surface 14 and lies smoothly against it, as shown in partial figure c) of Fig. 1 is illustrated. The Fig. The process shown in Figure 1 is also called “direct push-in”.

[0060] According to the invention, the receiving structure 22 comprises a network 26 constructed from filaments 24 or filament bundles, which forms the contact surface 23 of the laying die 10, to which the fiber mat piece 12 adheres due to the volume flow, wherein possible embodiments of this network 26 are shown in the photographs of the Fig. 3 to 6 are easier to see.

[0061] In these examples, the net 26 is woven, but other manufacturing processes are also possible, such as weaving, knitting, braiding or knotting.

[0062] The filaments can be made of a thermoplastic material, for example PP, PE, PET, PTFE, POM, or a mixture thereof, and in the example shown, they each have a thickness of 0.1 mm to 3 mm, preferably 0.2 mm to 1.5 mm, particularly preferably 0.5 mm to 1 mm. If desired, the filaments can be fiber reinforced. Selected or all filaments or filament bundles can also have a non-stick coating.

[0063] In the example of Fig. 1, the deformation of the carrier body 20 and the receiving structure 22 of the laying die 10 takes place purely passively by pressing against the target surface 14.

[0064] At the laying stamp 10 of the Fig. In contrast, in the second embodiment shown in simplified form in Figure 2, active deformability of the carrier body 20 and the receiving structure 22 is provided. For this purpose, the laying die 10 has a hinge plate 30 with, in this case, three rigid but hingedly coupled plate sections 32.

[0065] In the illustrated example, the central plate section 32 can be immovably attached to the base 18 by means of spacers 33 such that it is arranged at a suitable distance below the base 18 and runs parallel to it. Of course, in this example, suitable passages or lines for the volume flow must also be present between the device 25 and the contact surface 23, but these are not shown.

[0066] The right and left plate section 32 in Fig. 2 is connected to the central plate section 32 by a suitable hinge so as to be rotatable about a pivot axis S running in the transverse direction y and forms a plate pair 31 with it.

[0067] The pivot angle α, which the plates 32 of a plate pair 31 enclose with each other, can be changed and adjusted by an actuator 34 assigned to the plate pair 31. As a result, the shape of the contact surface 23 and the adhering material (in Fig. 2 not shown) piece of fiber mat must already be roughly adapted to the course of the target surface 14 at the desired location before the laying stamp 10 is pressed onto the target surface 14.

[0068] In the example shown, the two actuators 34 are each spindle drives, each supported at one end on the base 18 and connected at the other end by a ball joint to the respective plate section 32 of the joint plate 30. However, any other type of actuator is also possible, such as hydraulic or pneumatic actuators, and the type of support on the base and the coupling to the rigid plate sections 32 can also be varied according to the requirements of the individual case.

[0069] The joint plate 30 is firmly connected to the support body 20 on its distal side 30d, so that an adjustment of the pivot angle causes a deformation of the support body 20 and the receiving structure 22. The strongest deformation occurs in the areas V below the pivot axes S, as can be seen in the photograph of a prototype of the second embodiment in Fig. 4. In area V, the contact surface 23 folds significantly upwards.

[0070] Fig. However, Figure 4 also demonstrates that in the laying die 10 according to the invention, the fiber mat piece 12 held on the contact surface 23 does not follow the deformation of the contact surface 23, especially in the region V, which leads to a significant reduction in undesirable wrinkling when the fiber mat piece 12 is laid down on a target surface.

[0071] According to the inventors’ findings, the special design of the receiving structure as a network 26 made up of filaments is responsible for this.

[0072] This is net 26 in the view of the Fig. 3 and the detail enlargement in Fig. 6 to recognize more clearly.

[0073] This is a woven net with rectangular meshes, consisting of filaments 24.2 in the longitudinal direction x and filaments 24.1 (cf. Fig. 6) in the transverse direction y of the laying die 10. In another embodiment variant not shown here, the mesh 26 could also be oriented at a 45° angle to the longitudinal or transverse direction of the die, which can positively influence the deformability or elasticity of the mesh 26.

[0074] It can be provided that the filaments 24.2 in the longitudinal direction x and the filaments 24.1 in the transverse direction are designed differently with regard to diameter and / or material and / or number in order to ensure that the net 26 is adapted to bend about an axis B1 (cf. Fig. 3) parallel to the transverse direction y and for the second embodiment parallel to the pivot axes S of the joint plate 30 of the laying die 10 has a higher flexural rigidity than when bent about an axis B2 parallel to the longitudinal direction x, since this results in a more controlled deformation of the contact surface 23 of the laying die 10 when it is placed in such a way that the axis B1 or y or S runs parallel to the main axis of curvature of the target surface 14.

[0075] In the example of Fig. 3 and Fig. 4, the net 26 is attached or held at its outer periphery 26e to a frame 28, which may be made of an elastomeric material such as silicone, and which is fixed to the support body 20. The net 26 may be laid in a "floating" manner in the sense that it is attached to the support body 20 at most at certain points within the frame 28 and / or along individual lines, and preferably is not attached to the support body at all within the frame 28.

[0076] As in Fig. 5, the net 26 can be modularly constructed, particularly for larger laying dies 10, i.e., divided into several net sections 26, each of which is attached or held at its outer periphery 27e to a net section frame 29. Within the individual net section frames 29, the net 26 is again attached to the support body 20 at most at certain points and / or along individual lines, or not at all.

[0077] In particular, it can be provided that only those filaments 24.2 (cf. Fig. 6) of the net 26, which extend perpendicular to a predetermined direction R1, wherein the direction R1 preferably coincides with the transverse direction y of the bending punch in Fig. 1, so that the filaments 24.2 contributing to the contact surface all extend in the longitudinal direction x of the bending punch.

[0078] In example the Fig. 6, this is achieved in that the filaments 24.1 form the warp threads of the weaving structure shown there, which essentially run parallel to one another in a plane, while the filaments 24.2, which run perpendicular to the direction R1, form the weft threads which are alternately guided over and under the warp threads and thus lie in sections above the plane of the warp threads.

[0079] When positioning the fiber mat piece, the laying die 10 is then expediently aligned so that the predetermined direction R1 or transverse direction y coincides with the direction of the bending axis around which the net 26 is (mainly) bent when adapting to the target surface 14, as shown in Fig. 1 and Fig. 2 is the case

[0080] In this case, the filaments 24.2 which are in contact with the fibre mat piece 12 alone (cf. Fig. 6), due to their common orientation in the longitudinal direction x or R2 as guides, which promote the sliding of the fiber mat piece 12 on the net 26 in the longitudinal direction x. In this way, it is possible that the fiber mat piece 12 held on the contact surface 23 practically does not form any wrinkles, even in the region V of the greatest deformation of the carrier body 20 and the receiving structure 22, as in Fig. 4 is occupied.

[0081] Alternatively, to achieve this guiding effect, it would also be possible to arrange a layer of parallel, linear filaments 24.2 in the direction R2 on top of a layer of parallel, linear filaments 24.1 in the direction R1 (cf. Fig. 9a), so that a regular network is formed, and to connect the filaments, which preferably run perpendicular to each other, at their crossing points, e.g. by gluing or welding (cf. Fig. 9b), as simplified in Fig. 9, in which one of the bonding or welding points is provided with the reference number 21.

[0082] The material and geometric design of the net 26 result in the contact surface 23 of the receiving structure 22 being deformed by the laying die, which corresponds to a bending of the contact surface around the y-axis (transverse axis), as in Fig. 1b) illustrated adaptation to the target surface 14, wrinkles less than is the case with the laying dies known from the prior art, and in addition, the fiber mat piece 12 adhering to the laying die 10 can slide better in the longitudinal direction x relative to the contact surface 22d, which significantly reduces wrinkles in the fiber mat piece 12 deposited on the target surface 14.

[0083] The Fig. 7 and Fig. 8 finally show, in comparison, a piece of fiber mat 12 placed on the same spot of a similarly shaped target surface 14, wherein in Fig. 8 for depositing the inventive laying stamp according to Fig. 4 was used in Fig. 7 an almost identical laying die, but which has a conventional receiving structure instead of the filament net according to the invention.

[0084] In Fig. 7 shows clear bulges or folds of the fiber mat piece 12 at the points highlighted with light gray circles, while Fig. 8 demonstrates that these undesirable wrinkles can be virtually completely eliminated by using the laying stamp according to the invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2796263 A2 [0002, 0057] WO 2018162637 A1 [0002, 0056, 0057]

Claims

[1] Placement die (10) for automated positioning of a fiber mat piece (12) on a curved target surface (14), wherein the placement die (10) comprises: a connecting element (16) for connecting the laying die (10) to a robot arm (13), a rigid base (18) attached to the connecting element (16), preferably in the form of a base plate (19), an elastically deformable support body (20) provided on a distal side (18d) of the base (18), an elastically deformable receiving structure (22) attached to a distal side (20d) of the carrier body (20) for receiving and holding the fiber mat piece (12) on a contact surface (23) of the receiving structure, a device (25) for generating an adjustable volume flow at the contact surface (23), characterized by, that the receiving structure (22) comprises a network (26) made up of filaments (24) or filament bundles, which forms the contact surface (23). [2] Laying die (10) according to claim 1, wherein the filaments (24) or filament bundles comprise or are formed from a plastic with or without fiber reinforcement, wherein the plastic is preferably a thermoplastic plastic, which is particularly preferably selected from polypropylene, polyethylene, polyethylene terephthalate, polytetrafluoroethylene, polyoxymethylene or a mixture thereof. [3] Laying die (10) according to a preceding claim, wherein the filaments (24) or filament bundles have a thickness of 0.1 mm to 3 mm, preferably 0.2 mm to 1.5 mm, particularly preferably 0.5 mm to 1 mm. [4] Laying die (10) according to a preceding claim, wherein the net (26) is formed by weaving, braiding, knitting or crocheting or by direct joining at intersection points of the filaments or filament bundles. [5] Laying die (10) according to any of the preceding claims, wherein the net (26) is attached or held at its outer circumference (26e) to a frame (28), wherein the frame (28) is attached to the support body (20), and the net is attached to the support body within the frame at most at points and / or along individual lines, or wherein the net (26) is divided into several net sections (27) which are each attached or held at their outer perimeter (27e) to a net section frame (29), wherein the net section frames (29) are each attached to the support body (20) and the net (26) is attached to the support body (20) within the net section frames (29) at most at points and / or along individual lines. [6] Laying die (10) according to one of the preceding claims, wherein only those filaments (24) or filament bundles of the network (26) contribute to the contact surface (23) which extend substantially perpendicular to a first predetermined direction (R1), wherein preferably the contact surface in a longitudinal direction (x) of the laying die (10) is longer than in a transverse direction (y) and the first predetermined direction (R1) coincides with the transverse direction (y). [7] Laying die (10) according to one of the preceding claims, wherein a bending stiffness of the mesh (26) for a bend about a first axis (B1) parallel to a first predetermined direction (R1) is greater than for a bend about a second axis (B2) perpendicular to the first predetermined direction (R1), wherein preferably the bending stiffness for a bend about the first axis (B1) is two to five times the bending stiffness for a bend about the second axis (B2). [8] Laying die (10) according to claim 7, wherein the diameter of those filaments (24) or filament bundles which extend substantially perpendicular to the first predetermined direction (R1) is larger than the diameter of all other filaments (24) or filament bundles of the net (26), in particular at least twice as large. [9] Laying die (10) according to any one of claims 6 to 8, wherein the net (26) comprises more filaments (24) or filament bundles extending substantially perpendicular to the first direction (R1) than filaments (24) or filament bundles extending not perpendicular to the first direction (R1) and in particular parallel to the first direction. [10] Laying die (10) according to one of claims 6 to 9 wherein the filaments (24) of the net (26) which extend substantially perpendicular to the first direction (R1) have fiber reinforcement, while the filaments (24) of the net (26) which do not extend perpendicular to the first direction (R1) and in particular parallel to the first direction do not have fiber reinforcement. [11] Laying die (10) according to any one of claims 1 to 5, wherein the network (26) is formed from two groups of filaments (24) or filament bundles, wherein the filaments (24) or filament bundles of the first group extend at an angle of approximately + 45° to a longitudinal direction (x) of the contact surface (2§), and the filaments (24) or filament bundles of the second group extend at an angle of approximately - 45° to the longitudinal direction (x). [12] Laying die (10) according to any one of the preceding claims, wherein the laying die (10) further comprises a hinge plate (30) with at least one pair of plates (31) consisting of two rigid plate sections (32) rotatably coupled to each other about a pivot axis (S) and at least one actuator (34) associated with the plate pair (31), wherein the actuator (34) is attached to the base (18) and is designed to change a pivot angle (α) between the two rigid plate sections (32) of the plate pair (31), and wherein the support body (20) is attached to a distal side (30d) of the joint plate (30) such that the support body (20) and the receiving structure (22) are elastically deformable by a change in the swivel angle (α). [13] Laying die (10) according to claim 12, wherein the joint plate (30) comprises several pairs of plates (31) each consisting of two rigid plate sections (32) rotatably coupled to one another about a pivot axis (S), wherein the pivot axes (S) of the several pairs of plates (31) are parallel to each other, and wherein the laying die (10) comprises for each pair of plates (31) at least one actuator (34) associated with the pair of plates (31), which is supported at the base (18) and is configured to change a pivot angle (α) between the two rigid plate sections (32) of the respective pair of plates (31). [14] Laying die (10) according to claim 12 or 13, each in combination with one of claims 6 to 10, wherein the pivot axis (S) or pivot axes (S1) run parallel to the first direction (R1).

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