Fiber placement and production method

Abstract

A fiber application tool for a fiber placement and production method has a fiber contact surface area, which has a fiber contact surface for applying and/or pressing the fibers onto a work surface. The tool further includes an activation device for activating an adhesive, matrix, resin, or binder material provided at the fibers by means of an activation radiation so that the fibers are tacked onto the work surface. The fiber contact surface area for the activation radiation may be transparent and that the activation device may be designed so to guide and/or deliver the activation radiation through the transparent fiber contact surface area to the fibers to be pressed by the fiber contact surface.

Claims

1. A fiber placement method for automatic placement of fibers onto a work surface by a fiber application and/or compaction roller having a fiber contact surface formed at a circumference of the fiber application and/or compaction roller, the method comprising: a) applying and pressing fibers provided with adhesive, binder, matrix, or resin material by the transparent circumferential fiber contact surface; and b) guiding activation radiation starting from an interior of the fiber application and/or compaction roller through the transparent circumferential fiber contact surface for activating the adhesive, binder, matrix, or resin material.

2. The fiber placement method according to claim 1, wherein step b) occurs before step a).

3. The fiber placement method according to claim 1, further comprising delivering the fibers to the fiber application and/or compaction roller and redirecting the fibers to a redirection area until a contact with the work surface is established, wherein the activation radiation is guided in a focusing manner through the redirection area just prior to contacting the work surface onto the fibers.

4. A production method for producing matrix composite work pieces comprising: producing a preform by carrying out an automatic fiber placement method according to claim 1; and producing the work piece from the preform.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) In the following, exemplary embodiments of the present invention are described in more detail on the basis of the appended drawings.

(2) FIG. 1 shows a schematic illustration of a fiber placement device for the automatic placement of fibers;

(3) FIG. 2 shows a schematic side view for illustrating the principle of the automatic fiber placement and a plurality of devices at the placement head of the fiber placement device including a fiber application tool;

(4) FIG. 3 shows a sectional view of a first embodiment of a fiber application tool;

(5) FIG. 4 shows a sectional view through a fiber application tool according to a second embodiment;

(6) FIG. 5 shows a schematic perspective view of a further embodiment of the fiber application tool; and

(7) FIG. 6 shows a schematic perspective view of a further embodiment of the fiber application tool.

DETAILED DESCRIPTION

(8) FIGS. 1 and 2 schematically illustrate a fiber placement device 10 when carrying out an automatic fiber placement method, in particular, an AFP method or fiber placement method. For this purpose, FIG. 1 shows an overview of the fiber placement device 10, while FIG. 2 schematically shows in greater detail a detail view of a placement head 12 having a fiber application tool 14.

(9) Fiber placement device 10 is designed for the automatic placement of fibers 16 onto a work surface 18. In particular, the fiber placement device is designed for placing fibers 16 onto a surface of a form tool 20. For this purpose, fiber placement device 10 has a control 22, in which a respective lay-down plan for laying-down fibers 16 onto respective work surface 18 known from the form is filed. Fibers 16 are placed in predefined paths and have a predefined quantity.

(10) Fibers 16 may appear in varying forms, for example, different fiber material, for example, fiber bands, spread fiber bundles, fiber filament or the like may be used, and the fiber material when processed in placement head 12 is already provided with an adhesive material, a matrix material, or resin material. For example, a prepreg fiber filament band or a binder-impregnated fiber band may be delivered.

(11) For this purpose, fiber placement device 10 has a motion apparatus 24, by which placement head 12 having fiber application tool 14 may be moved along specified paths of work surface 18. Motion apparatus 24 has, for example, a robotic arm 26. In this way, placement head 12 is movable in direction X, direction Z, and direction Y; furthermore, said placement head 12 is rotatable in a desired orientation. In FIG. 2, placement head 12 is corresponding to its movement indicated by a velocity vector v.

(12) At placement head 12, a fiber delivery device 30 is provided for delivering fibers 16 still in continuous form and a cutting device 32 for cutting fibers 16 to a desired length.

(13) Furthermore, fiber application tool 14 has a fiber contact surface 34, which contacts to-be-placed fibers 16 to redirect them, apply them to work surface 18, and to press and compact them under pressure.

(14) As already mentioned above, fibers 16 are delivered having an activatable adhesive material, matrix material, resin material, or binder material, which may be activated by heat and, in particular, by means of an activation radiation 36. Activation radiation 36 is preferably designed in the form of a light radiation or infrared radiation.

(15) For this purpose, fiber application tool 14 has an activation device 38 for delivering activation radiation 36.

(16) Fiber contact surface 34 is formed at a fiber contact surface area 40 of fiber application tool 14, and fiber contact surface area 40 is transparent for activation radiation 36.

(17) Activation device 38 is designed in such a manner that activation radiation 36 radiates from behind, starting from the side opposite of fiber contact surface 34 of fiber contact surface area 40 through fiber contact surface area 40 to fiber contact surface 34 to irradiate fibers 16 engaging at fiber contact surface 34 and, thus, to activate the respective adhesive material or binder material.

(18) Fiber application tool 14 has, in particular, a fiber application and/or compaction roller 42. Fiber contact surface 34 is formed at a circumferential area of fiber application and/or compaction roller 42. In other words, a circumferential areafor example, a circumferential partitionof fiber application and/or compaction roller 42 forms fiber contact surface area 40 and is, at least partially, made up of the transparent material for activation radiation 36. Fiber application and/or compaction roller 42 is mounted in a rotating manner at placement head 12 and may roll, by moving placement head 12 along work surface 18, onto work surface 18. In this instance, said fiber application and/or compaction roller 42 redirects, as shown in FIG. 2, fibers 16 coming from fiber delivery device 30 and presses said fibers onto work surface 18.

(19) Activation device 38 has, in particular, a light source 44, preferably in the form of at least one LED 46. The refinements illustrated in FIGS. 3 through 5 are, however, designed in such a manner that light source 44 or LED 46 is situated internally of fiber application and/or compaction roller 42. In the embodiment illustrated in FIG. 6, activation device 38 has a guiding device 72, such as, in particular, a glass fiber 74 or a light conductor, by which, in an external radiation source 76, for example, an external LED, produced activation radiation may be guided into the interior area of fiber application and/or compaction roller 42.

(20) In particular, fiber application and/or compaction roller 42 and activation device 38 form a very compact unit in this manner. Fiber application tool 14 thus may limit its exterior dimensions to the exterior dimensions of fiber application and/or compaction roller 42. For example, the largest dimensionfor example, formed by the diameter of roller 42is less than 10 cm, in particular, less than 5 cm and, in particular, more than approximately 2 cm (+/0.5 cm).

(21) FIGS. 3, 4, and 6 show possible refinements of fiber application tool 14.

(22) Accordingly, fiber application and/or compaction roller 42 has a roller body or tubular body 48 having a cylinder barrel (example for a circumferential partition) made up of transparent plastic or glass or miscellaneous transparent, resistant, and compactable material for activation radiation 36. In the interior of tubular body 48 or roller body, LED 46 or the outlet of light conducting device 72 is provided. Furthermore, a focusing device 50 for focusing activation radiation 36 onto the exterior surface of tubular body 48 may be provided. Tubular body 48 forms fiber contact surface area 40 and the outer circumferential surface of tubular body 48 forms fiber contact surface 34. Focusing device 50 delivers in particular a focus point immediately at this exterior surface and, for this reason, at fiber contact surface 34. It is also possible, depending on the thickness of to-be-delivered fibers 16, to situate the focus point in close distance just outside of the outer circumferential surface and, thus, to situate it in the interior of fibers 16 thereon engaged.

(23) Focusing device 50 may have one or a plurality of focusing lenses 52.

(24) According to a further refinement and as indicated in FIG. 4, a collimator device 54 having at least one collimator lens 56 may be provided. The focusing device may, however, also be completely omitted, as indicated in FIG. 6. Even though the last option not having a focusing device is illustrated by the example of the external radiation production and guiding device, it is also possible in refinements producing radiation internally, when the radiation is sufficiently high.

(25) As shown in FIG. 2, activation device 38 is preferably devised in such a manner that it irradiates activation radiation 36 into redirection area 58, where fibers 16 are redirected, and which is in rotational direction located just in front of contact point 60, where fibers 16 are pressed onto work surface 18 by fiber application and/or compaction roller 42. Using tubular body 48, placement head 12 presses fibers 16 with force F onto work surface 18, while it is moved across work surface 18 by velocity v.

(26) A possible, specific construction of fiber application tool 14 is illustrated in FIG. 5.

(27) Here, outer tubular body 48 is mounted in a rotating manner by ball bearings 62 at a bearing segment 64, which may be, by means of a fixing unit 66, fixed in a stationary manner to a positioning device at placement head 12. At bearing section 64, activation device 38 having LED 46 and focusing device 50 is provided in the interior of transparent tubular body 48.

(28) The position and radiation direction of activation device 38 may be adjusted by respectively positioning fixing unit 66. The application of the fibers and compaction are carried out by rolling tubular body 48 by means of fiber contact surface 34 formed at the outer circumference of tubular body 48.

(29) Respective fiber placement device 10 is able to carry out an extremely advantageous automatic fiber placement method. Activation device 38 is located in the interior of fiber application and/or compaction roller 42; for this reason, placement head 12 is embodied in an extremely compact manner and activation device 38 is safely situated.

(30) Activation radiation 36 may be specifically metered and carried out with a low radiation intensity. Respectively, less energy input is required.

(31) As illustrated in FIG. 1, in particular a preform of a work piece made up of fiber-reinforced composite material may be produced in this instance. Form tool 20 having the preform subsequently produced by laying down fibers 16 may then be produced in further processes known in principle by respective soaking using resin-matrix material and the like.

(32) Although fiber application tool 14 and the thereby provided fiber placement device 10 is described by the example of AFP methods having a roller for pressing fibers, the present invention is not limited to the tools or devices or methods respectively designed for carrying out an AFP method. For example, the idea of an activation by an activation radiation guided through a transparent fiber contact surface area could be also realized in other placement devices, for example, a laying die, having other forms of fiber contact surfaces, in particular, in so-called fiber patch preforming methods, as shown and described in WO2008/110614.

(33) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

LIST OF REFERENCE CHARACTERS

(34) 10 Fiber placement device 12 Placement head 14 Fiber application tool 16 Fiber 18 Work surface 20 Form tool 22 Control 24 Motion apparatus 28 Robotic arm 30 Fiber delivery device 32 Cutting device 34 Fiber contact surface 36 Activation radiation 38 Activation device 40 Fiber contact surface area 42 Fiber application and/or compaction roller 44 Light source 46 LED 48 Tubular body 50 Focusing device 52 Focusing lens 54 Collimator device 56 Collimator lens 58 Redirection area 60 Contact surface 62 Ball bearing 64 Bearing section 66 Fixing unit 68 Preform 70 Focus point 72 Guiding device 74 Glass fiber 76 External radiation source, for example external light generator, such as LED