DE102010054933A1 - Device, useful for producing complex three-dimensionally shaped fiber reinforced preform from two-dimensional planar fiber assembly, comprises molding tool with mold contour which maps the complex-dimensional shape of preform - Google Patents

Abstract

Device for producing a complex three-dimensionally shaped fiber reinforced preform from a two-dimensional planar fiber assembly (1) comprises: a molding tool (2) with a mold contour which maps the complex-dimensional shape of the preform; a feasible automated handling device (3) for the fiber assembly, where the two-dimensional planar fiber assembly is positionable by the handling device above the mold contour of the molding tool; an upper tool (4) with a counter-mold contour, which is complementary to the mold contour, where the upper tool is arranged on the handling device. Device for producing a complex three-dimensionally shaped fiber reinforced preform from a two-dimensional planar fiber assembly (1) comprises: a molding tool (2) with a mold contour which maps the complex-dimensional shape of the preform; a feasible automated handling device (3) for the fiber assembly, where the two-dimensional planar fiber assembly is positionable by the handling device above the mold contour of the molding tool; an upper tool (4) with a counter-mold contour, which is complementary to the mold contour, where the upper tool is arranged on the handling device; where the handling device comprises biasing device for clamping the fiber assembly against the counter-mold contour of the upper tool and the device comprises bulk material (5) and a bulk material supply device comprising at least one outlet opening in the upper tool, which is openable by the supply device, controlling actuation device through the two-dimensional planar fiber assembly to its filling, where the fiber assembly arranged in the molding tool starting with the bulk material is continuously rising filled from a lowest point of the mold contour. An independent claim is also included for a method for producing a complex three-dimensionally shaped fiber reinforced preform from a two-dimensional planar fiber assembly comprising: taking up the fiber assembly through the handling device and clamping of the fiber assembly against the counter-mold contour of the upper tool by the biasing device and preforming the fiber assembly; positioning the preformed fiber assembly over the mold contour of the molding tool by the handling device; supplying a first portion of the bulk material by the bulk material supply device through at least one outlet port in the counter-contour of the upper tool to the fiber assembly arranged at the molding tool through the mold contour at a lowest point of the mold contour; and starting from the lowest point of the mold contour supplying further portions of bulk material further continuously rises points of the mold contour on the fiber assembly, where progressively molding of the two-dimensional planar fiber assembly to the mold contour takes place and obtaining the complex-shaped three-dimensional preform.

Description

The invention relates to an apparatus and a method for producing fiber-reinforced preforms, which are provided for the representation of fiber-reinforced fiber composite plastic components.

The draping of two-dimensional fabrics into complex three-dimensional shapes has heretofore been largely done by hand. An automated concept is offered by the vacuum process: Here, the fiber mats are placed on the shape to be imaged and on the fiber mats a rubber mat. The space between the mold and rubber mat is evacuated and the fiber mats are thus applied to the mold. With the help of such vacuum methods, only three-dimensional shapes with simple geometries can be mapped so far.

Also the EP 0 577 505 A1 uses pressure differences for deformation layers to form a multi-layered composite material. This is made by means of a plant by bringing together pre-cut unit layers. The system consists of a forming die and a tool for gripping, forming and compacting. This tool has a support element and a counter-shape, which is complementary to the forming die and is attached to the support element. Further, the tool comprises a flexible membrane secured with its outer edge opposite the counter-mold on an edge of the support member and means for generating a negative pressure between the counter-mold and the flexible membrane, and means for pressing the membrane against the mold-die. The membrane is attached to a flat edge of the support element, so that it does not come into contact with the counter-mold. Furthermore, the membrane is equipped on its side remote from the counter-mold side with vacuum suction pads. This system makes it possible to grasp the cut and possibly resin-impregnated unit layers as well as their shaping and compaction completely automatically.

Based on this prior art, the object is to provide an optimized, easily formed device for the fully automatic production of a complex three-dimensionally shaped fiber-reinforced preform with high contour accuracy from a two-dimensional planar fiber arrangement.

This object is achieved by a device having the features of claim 1.

The object of the creation of a fully automatic method, with which fiber-reinforced preforms can be produced reproducibly and contour-true, is achieved by a method having the features of claim 7.

Further developments of the device and the method are carried out in the respective subclaims.

In a first embodiment of the device of the present invention, a complex three-dimensionally shaped, fiber-reinforced preform is produced from a two-dimensional planar fiber arrangement by means of a device which has a molding tool which displays a molding contour which images the complex three-dimensional shape of the preform. Furthermore, the device has an automated, feasible handling device for the fiber arrangement, wherein the two-dimensional planar fiber arrangement can be positioned by means of the handling device over the mold contour in the molding tool. Furthermore, the device comprises an upper tool, which has a Gegenformkontur, which is complementary to the shape contour of the mold. The upper tool is arranged on the handling device.

According to the invention, the handling device now has pretensioning means with which the fiber arrangement can be stretched and preformed against the counterform contour of the upper tool, wherein the apparatus additionally comprises bulk material and a bulk material feed device which comprises one or more outlet openings in the upper tool. When the fiber assembly is positioned over the mold contour of the mold, the outlet opening or openings in the upper tool can be opened by means of an actuator controlling the feeder to fill the fiber assembly with the bulk material for molding according to the mold contour. As a result of the controlled actuation of the outlet openings, the fiber arrangement arranged in the molding tool is filled with the bulk material in a steadily increasing manner starting from a lowest point of the mold contour.

Advantageously, the feed device for the bulk material has a plurality of outlet openings in the upper tool, which are distributed over the mating contour, and which can be actuated and actuated individually by the actuating device in order to allow a guided molding of the fiber arrangement to the mold contour.

For this purpose, the individual outlet openings are controlled as a function of a supplied bulk material quantity and as a function of their position on the mating contour in order to fill the fiber arrangement starting from a lowest point of the mold contour in a steadily increasing manner. For this purpose, first a first opening at a lowest point of Opposite contour of the upper tool are opened to allow the bulk material to emerge there, and further outlet openings are opened at other, higher places of the mating contour of the upper tool in the further course of the filling to completely fill the fiber assembly with bulk material and so the molding of the mold contour of the mold.

Due to the fact that the tensioning means of the handling device hold the fiber mat under tension, wrinkling during filling with the bulk material is prevented, it is further provided that the handling device has means for tracking the fiber arrangement, which is coupled to the actuating device and thus in dependence on a supplied bulk material quantity can be actuated so that the held under tension fiber assembly can adapt to the contour during further filling.

The bulk material may be approximately spherical bodies. Preferably, balls are used which allow uniform coverage of the fiber assembly surface corresponding to the mold contour and provide in close-packed packing a total weight that fixes the fiber assembly in the mold. Size and / or weight of the bulk material particles, in particular of the balls, can be selected according to the complexity of the shape contour. The smaller the balls, the higher the dimensional accuracy and the more complex structures are possible. The weight of the balls is selectable, for example, depending on the type of fiber arrangement which is to be molded in the mold to be fixed. The stiffer and heavier the fiber arrangement, the greater the required weight of the bulk material.

In one embodiment, the upper tool may comprise not only the bulk material supply means but also a bulk material storage means.

Furthermore, the device according to the invention may comprise emptying means, with the aid of which the bulk material can be removed from the preform after completion of the molding process. The emptying means may, for example, be a tilting device provided on the mold with which the mold is simply tilted in order to empty the bulk material, but the emptying means may also be an axle suction pump coupled to the feed device, so that the bulk material aspirated directly after completion of the molding process and can advantageously be transferred back into a storage device. Furthermore, it is conceivable that the device comprises a bulk material collecting cloth as emptying means, which can be deposited by means of a depositing device on the side of the fiber arrangement facing away from the forming tool prior to filling with the bulk material. After completion of the molding process, the bulk material collecting cloth can then be removed together with the bulk material.

An inventive embodiment of the method for producing the complex three-dimensionally shaped continuous fiber reinforced preform from two-dimensional planar fiber assemblies comprises first receiving the fiber assembly by the handling device, wherein the fiber assembly are stretched by the biasing means of the handling device against the Gegenformkontur of the upper tool and thus preformed. Then, the preformed fiber assembly is positioned over the mold contour of the mold by the handling device, and a first portion of the bulk material is conveyed by the bulk material feed device through the at least one outlet opening in the mating contour of the upper tool to the fiber arrangement disposed above the mold contour in the mold at a lowest point of the mold contour drained. Starting from the lowest point of the mold contour, further bulk material portions are discharged onto the fiber arrangement via further steadily rising points of the mold contour so that the two-dimensional planar fiber arrangement is formed stepwise onto the mold contour and thus the complex three-dimensionally shaped preform is obtained.

The fiber arrangement can be tracked controlled in dependence on a supplied bulk material and kept under tension.

The removal of the bulk material after preforming of the preform is then carried out either by tilting the mold or by activating a coupled with the feeder suction. Another alternative is the removal of the bulk material together with a bulk material collecting cloth, which was placed on the side facing away from the mold side of the fiber assembly prior to the supply of the bulk material.

The molding process is guided, reproducible and fully automatic, whereby the bulk material ensures a high contour accuracy. There is no special tool such as vacuum pump or pressure pump and required to sealing means on the tool needed. By using the upper tool by which the fiber assembly is preformed, the Einformzeiten be reduced and it requires only a minimum amount of bulk material to complete the fiber assembly to complete.

These and other advantages are set forth by the following description with reference to the accompanying figures.

The reference to the figures in the description is to aid in the description and understanding of the subject matter. The figures are merely a schematic representation of an embodiment of the invention.

Showing:

1 FIG. 2 a schematic side sectional view of the device according to the invention during a first method phase, FIG.

2 a schematic side sectional view corresponding 1 during a second process phase.

The device according to the invention and the method according to the invention relate to the production of fiber-reinforced preforms, which are provided for the representation of fiber composite plastic components, from a two-dimensional planar fiber arrangement. A two-dimensional planar fiber arrangement is understood as meaning, for example, a woven fabric, scrim, multiaxial scrim, braid, mat or fleece, wherein the reinforcing fibers need not exclusively be glass fibers, carbon fibers and aramid fibers, but may also be other fibers.

The two-dimensional sheet fiber assembly may be dry or soaked with matrix material such as a resin, but may also be infiltrated with the matrix material, for example, with a thermoplastic melt after it has been reshaped. It is also possible to use fiber-reinforced non-consolidated or only partially consolidated semi-finished products, such as an organic sheet (fiber-reinforced thermoplastic sheet) or a hybrid fabric with reinforcing fiber and matrix fiber fraction.

The device according to the invention represents a simple and cost-effective solution for the automatic draping of two-dimensional fabric mats into a complex, three-dimensional mold. Several superimposed fabric layers of the mold can be adjusted, wherein the fabric mats are inserted in a guided process and ensure high insertion quality and process reliability , Advantageously, the device of the invention does not work with pressure variations and therefore also requires no consuming suction pads with passages to vacuum sources or pressure sources or vacuum circuits. Therefore, a corresponding seal is not necessary.

2 shows sketched the device according to the invention, in which the handling device 3 the fiber arrangement 1 already taken up and against the Gegenformkontur 4a of the upper tool 4 attached to the handling device 3 is arranged, biased, so that the fiber mat 1 even before introduction to the mold 2 through the upper tool 4 is approximately aligned.

To the fiber mat 1 against the counter-contour of the upper tool 4 to tension, the handling device 3 corresponding biasing means 3a on. For the further molding process, the device according to the invention comprises bulk material 5 , this one in the upper tool 4 is stored, but also outside the upper tool 4 can be stored and could only be supplied by a suitable bulk material feeder.

To now the fiber mat 1 by means of the bulk material in the mold contour 2a of the mold 2 mold, has the upper tool 4 at least one outlet opening 4b on, through which the bulk material on the fiber mat 1 passes and according to the shape contour 2a can map.

In one embodiment, it is conceivable that the upper tool relative to the handling device 3 is movable and can be moved vertically upwards, leaving a single outlet opening 4b at the lowest point of the upper tool 4 sufficient for the fiber mat 1 in the shape contour 2a completely filled. However, it is also possible for there to be a plurality of outlet openings distributed over the mating contour on the upper tool, which can be opened successively one after the other to the fiber arrangement 1 with the bulk material 5 to fill and thereby according to the shape contour 2a to mold.

The opening of the respective outlet openings can take place via an actuating device controlling the supply device, so that the opening of the individual outlet openings can be controlled as a function of the quantity of bulk material supplied. So that the prestressed fiber mat 1 to the shape contour 2a can adjust by supplying bulk material, the handling device 3 medium 3a for tracking the fiber arrangement, which are operated in response to the amount of bulk material supplied. In one embodiment, they can only yield to the increasing weight with the increasing quantity of bulk material, so that the fiber mat is kept under tension in a controlled manner. The tracking and tensioning means can also be coupled to the actuating device which controls the feed device and is actuated as a function of the quantity of bulk material supplied.

The so with the help of the handling device 3 preformed and approximately in the mold 2 inserted fiber mat 1 is starting from the lowest point of the mold 2 by the supply of the balls 5 on the fiber assembly 1 formed.

This is done by the use of the bulk material correctly and contour. Thus, starting from the lowest point of the mold, a guided molding process is shown, whereby the high laying quality and process reliability can be achieved.

After the molding process, the bulk material can be distributed by a tiltable designed mold or sucked directly by a suction pump, which is coupled to the feeder.

Or it can be used a bulk bag, which in advance on the of the mold 2 opposite side of the fiber assembly 1 was arranged so that the bulk material does not rest directly on the fiber mat but on the bulk-collecting towel. After completion of the molding process, the bulk material collection cloth can then be removed together with the bulk material.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The 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

• EP 0577505 A1 [0003]

Claims (9)

Device for producing a complex three-dimensionally shaped fiber-reinforced preform from a two-dimensional flat fiber arrangement ( 1 ), wherein the device - a mold ( 2 ) with a shape contour ( 2a ), which depicts the complex three-dimensional shape of the preform, - an automated handling device ( 3 ) for the fiber arrangement ( 1 ), wherein the two-dimensional planar fiber arrangement ( 1 ) by means of the handling device ( 3 ) over the mold contour ( 2a ) of the molding tool ( 2 ), and - an upper tool ( 4 ) with a counterform contour ( 4a ), which are complementary to the shape contour ( 2a ) is formed, wherein the upper tool ( 4 ) on the handling device ( 3 ), characterized in that the handling device ( 3 ) Biasing means ( 3a ) for tensioning the fiber assembly ( 1 ) against the counterform contour ( 4a ) of the upper tool ( 4 ), and that the device bulk material ( 5 ) and a bulk material supply device with at least one outlet opening ( 4b ) in the upper tool ( 4 ), which is controlled by means of an actuating device controlling the feed device above the two-dimensional flat fiber arrangement ( 1 ) is openable to the filling, wherein in the mold ( 2 ) arranged fiber arrangement ( 1 ) with the bulk material ( 5 ) starting from a lowest point of the shape contour ( 2a ) is steadily increasing fillable. Apparatus according to claim 1, characterized in that the supply device ( 4 ) a plurality of outlet openings ( 4b ) in the upper tool ( 4 ), which via the mating contour ( 4b ), wherein the outlet openings ( 4b ) can be actuated and actuated individually by the actuating device controlling the feed device, an actuation of the individual outlet openings ( 4b ) is provided controlled in response to a supplied bulk amount. Apparatus according to claim 1 or 2, characterized in that the handling device ( 3 ) Medium ( 3a ) for tracking the fiber arrangement ( 1 ), which are coupled to the actuating device controlling the feeding device and can be actuated in dependence on a supplied bulk material quantity. Device according to at least one of claims 1 to 3, characterized in that the bulk material ( 5 ) of approximately spherical bodies, preferably of spheres ( 5 ) whose size and / or weight of the shape contour ( 2a ) and / or a type of fiber arrangement ( 1 ) is adjusted. Device according to at least one of claims 1 to 4, characterized in that the upper tool ( 4 ) a storage device for the bulk material ( 5 ). Device according to at least one of claims 1 to 5, characterized in that the device emptying means for removing the bulk material ( 5 ), wherein the emptying means in particular - one on the mold ( 2 ) tipping device or - a suction pump coupled to the supply device or - a bulk material collecting cloth, which by means of a depositing device of the device on the of the mold ( 2 ) facing away from the fiber assembly ( 1 ) before filling with the bulk material ( 5 ) can be stored. Method for producing a complex three-dimensionally shaped continuous fiber reinforced preform from a two-dimensional flat fiber arrangement ( 1 ) using a device according to at least one of claims 1 to 6, comprising the steps: - picking up the fiber arrangement ( 1 ) by the handling device ( 3 ) and tensioning the fiber assembly ( 1 ) against the counterform contour ( 4a ) of the upper tool ( 4 ) by means of the biasing means ( 3a ) and thus preforms the fiber arrangement ( 1 ), - positioning the preformed fiber assembly ( 1 ) over the mold contour ( 2a ) of the molding tool ( 2 ) by the handling device ( 3 ), - feeding a first portion of the bulk material ( 5 ) by means of the bulk material supply device through the at least one outlet opening ( 4b ) in the counter contour ( 4a ) of the upper tool ( 4 ) to the above the shape contour ( 2a ) in the mold ( 2 ) arranged fiber arrangement ( 1 ) at a lowest point of the shape contour ( 2a ) - starting from the lowest point of the shape contour ( 2a ) Supplying further bulk material portions via further steadily rising points of the shape contour ( 2a ) on the fiber arrangement ( 1 ), thereby gradually forming the two-dimensional planar fiber arrangement ( 1 ) to the shape contour ( 2a ) and obtaining the complex three-dimensional shaped preform. Method according to claim 7, comprising the step of: - controlled in dependence of a supplied quantity of bulk material tracking and keeping the fiber arrangement under tension ( 1 ). Method according to claim 7 or 8, comprising the step of: after obtaining the preform taking out the bulk material ( 5 ) by - tilting the mold ( 2 ) or - activation of the suction pump coupled to the supply device or - removal of a bulk material collecting bag together with the bulk material ( 5 ), wherein the bulk material collecting cloth before the supply of bulk material ( 5 ) to that of the mold ( 2 ) facing away from the fiber assembly ( 1 ) was laid.

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