SEMI-FINISHED FIBER PRODUCT LAY-UP HEAD

Abstract

The invention relates to a semi-finished fiber product lay-up head (1) for laying flat semi-finished fiber products (2), the semi-finished fiber product lay-up head having an electrically conductive electrode (6) which is contacted with the semi-finished fiber products to be layed, so that a current flow from a corresponding counter-electrode (7) in the fiber semi-finished product is effected in order to heat the same.

Claims

1. A semi-finished fiber product lay-up head for laying semi-finished fiber products in or on a molding tool or a combination of the semi-finished fiber product lay-up head and the molding tool, wherein the semi-finished fiber product lay-up head is configured for infeeding the semi-finished fiber products by way of a material supply installation, comprising: at least one electrode for applying a voltage that is connectable to an electrical energy source, wherein the at least one electrode electrically contacts the semi-finished fiber products that are infed to the semi-finished fiber product lay-up head; at least one counter electrode that electrically contacts the semi-finished fiber products that are infed to the semi-finished fiber product lay-up head, wherein the at least one electrode interacts with the at least one counter electrode in such a manner that a current flow is effected in a portion of the semi-finished fiber products that is defined by the contact with the at least one electrode and the contact with the at least one counter electrode.

2. The semi-finished fiber product lay-up head or combination as claimed in claim 1, further comprising: at least one lay-up unit which is configured for laying up the semi-finished fiber products that are infed to the semi-finished fiber product lay-up head in or on the molding tool, wherein the at least one electrode is at least partially disposed on the at least one lay-up unit; is formed by the at least one lay-up unit; or is disposed ahead of or behind the lay-up unit in relation to an infeeding direction (D.sub.infeed) of the infed semi-finished fiber products.

3. The semi-finished fiber product lay-up head or combination as claimed in claim 1, wherein the at least one counter electrode is physically associated with the semi-finished fiber product lay-up head.

4. The semi-finished fiber product lay-up head or combination as claimed in claim 3, wherein the at least one counter electrode, in relation to an infeeding direction (D.sub.infeed) of the infed semi-finished fiber products, is disposed ahead of or behind the at least one electrode so as to be spaced apart from the latter.

5. The semi-finished fiber product lay-up head or combination as claimed in claim 1, further comprising: at least one lay-up unit which is configured for laying up the semi-finished fiber products that are infed to the semi-finished fiber product lay-up head in or on the molding tool, wherein the at least one counter electrode in relation to an infeeding direction (D.sub.infeed) of the infed semi-finished fiber products is disposed ahead of or behind the lay-up unit so as to be spaced apart from the latter.

6. The semi-finished fiber product lay-up head or combination as claimed in claim 1, comprising: at least one first lay-up unit; at least one second lay-up unit that is disposed spaced apart from the first lay-up unit, wherein said first and second lay-up units are each configured for laying up the semi-finished fiber products that are infed to the semi-finished fiber product lay-up head in or on the molding tool, wherein the at least one electrode for electrically contacting the infed semi-finished fiber products is disposed on the first lay-up unit or is formed by the first lay-up unit; and the at least one counter electrode for electrically contacting the infed semi-finished fiber products is disposed on the second lay-up unit or is formed by the second lay-up unit.

7. The semi-finished fiber product lay-up head or combination as claimed in claim 3, wherein the at least one electrode is disposed such that the infed semi-finished fiber products electrically contact the electrode on a first side, and the at least one counter electrode is disposed such that the infed semi-finished fiber products electrically contact the counter electrode on a second side that is opposite the first side.

8. The semi-finished fiber product lay-up head or combination as claimed in claim 7 wherein at least one of the first and second lay-up units is configured as a lay-up roller.

9. The semi-finished fiber product lay-up head or combination as claimed in claim 1, further comprising: at least one roller which across a circumferential face of the at least one roller contacts the infed semi-finished fiber products and which in the circumferential face of the at least one roller has one or more of the at least one electrode and the at least one counter electrode for electrically contacting the semi-finished fiber products.

10. The semi-finished fiber product lay-up head or combination as claimed in claim 1 further comprising at least one lay up unit, and wherein one or more of the at least one electrode, the at least one counter electrode, the at least one lay-up unit, and the semi-finished fiber product lay-up head is configured for exerting a force in the direction of the infed semi-finished fiber products for compacting the fibers of the semi-finished fiber products.

11. The semi-finished fiber product lay-up head or combination as claimed in claim 1, further comprising: an output regulator unit adapted for regulating electrical output of current flow that is effected in the semi-finished fiber product so as to depend on a velocity of the semi-finished fiber product lay-up head.

12. The semi-finished fiber product lay-up head or combination as claimed in claim 1 wherein the at least one electrode includes a plurality of electrical electrodes, and the at least one counter electrode includes a plurality of counter electrodes, and further comprising an electrode controller unit adapted for applying an electrical voltage in each case sequentially to one of the plurality of electrodes and to switch remaining electrodes of the plurality of electrodes and a portion of the plurality of counter electrodes in such a manner that a current flow is effected between the one of the plurality of electrodes and a predefined counter electrode of the plurality of counter electrodes.

13. A fiber laying device for producing a fiber scrim of a fiber-composite component, comprising: a molding tool for laying semi-finished fiber products; and a semi-finished fiber product lay-up head as claimed in claim 1.

14. The fiber laying device as claimed in claim 13 wherein the molding tool functions as the counter electrode and has an at least partially electrically conducting and shape-imparting tool surface.

15. A method for laying semi-finished fiber products in or on a molding tool, comprising: a) providing a semi-finished fiber product lay-up head which lays up semi-finished fiber products that are infed thereto in or on the molding tool, wherein the semi-finished fiber product lay-up head has at least one electrode for electrically contacting the infed semi-finished fiber products; b) providing at least one counter electrode for electrically contacting the semi-finished fiber products; and c) applying a voltage to the at least one electrode and the at least one counter electrode so as to generate a current flow in a portion of the semi-finished fiber products that is defined by contact with the at least one electrode of the semi-finished fiber product lay-up head and contact with the at least one counter electrode when the semi-finished fiber products are being laid up in or on the molding tool.

16. The method as claimed in claim 15, wherein the a molding tool has an at least partially electrically conducting and shape-imparting tool surface for forming the at least one counter electrode, and comprising the step of laying up the semi-finished fiber products on the tool surface by the semi-finished fiber product lay-up head.

17. The method as claimed in claim 15 further comprising the step of compacting the fibers of the semi-finished fiber products using a contact pressure force in a direction of the semi-finished fiber products is-exerted by way of one or more of the at least one electrode, the at least one counter electrode, and the semi-finished fiber product lay-up head.

Description

[0048] The invention will be explained in an exemplary manner by means of the appended figures in which:

[0049] FIG. 1 shows a schematic illustration of a lay-up head having an electrode;

[0050] FIG. 2 shows a schematic illustration of a lay-up head having an upstream electrode roller pair;

[0051] FIG. 3 shows a schematic illustration of a lay-up head having two lay-up units;

[0052] FIG. 4 shows a schematic illustration of a lay-up head having an upstream electrode and counter electrode;

[0053] FIG. 5 shows a schematic illustration of a lay-up head having an electrode and a counter electrode in a mutually opposite manner;

[0054] FIG. 6 shows a schematic illustration of a contact roller in a particular embodiment.

[0055] The invention will be explained hereunder by means of a plurality of exemplary embodiments. The same reference signs are in each case used for the same features in the various figures.

[0056] FIG. 1 schematically shows a lay-up head 1 by way of which semi-finished fiber products 2 can be laid up on a molding tool 3. The semi-finished fiber products 2 herein can be laid up directly onto the tool surface 3a of the molding tool or, when a multi-tiered construction of the fiber scrim is to be produced, also onto semi-finished fiber products that have already been laid up.

[0057] The lay-up head 1 has a fiber material infeed 4 by way of which the semi-finished fiber products 2 are infed to the lay-up head 1. The semi-finished fiber products 2 herein are infed by way of the fiber material infeed 4 from a material supply installation (not illustrated). A plurality of fiber material infeeds and material supply installations are also conceivable.

[0058] The semi-finished fiber products 2 that are infed by way of the fiber material infeed 4 are then guided by way of one or a plurality of deflection rollers across at least one lay-up unit 5 which in the exemplary embodiments of the figures is configured as a roll or lay-up roller, respectively. By guiding the semi-finished fiber products 2 on the lower side, the lay-up head 1 by way of the lay-up roller 5 continuously presses the fiber materials onto the tool 3, on account of which the semi-finished fiber products 2 are laid up on or in the molding tool 3.

[0059] In the exemplary embodiment illustrated in FIG. 1, the lay-up roll 5 is configured to be electrically conducting such that said lay-up roll 5 forms the electrode 6 of the lay-up head 1. To this end, the lay-up roll 5 can be composed of an electrically conductive material, or be sheathed by the latter. It is also conceivable that the lay-up roll 5 is equipped with an electrically conductive material only partially on the circumference, so as to form the electrode 6 of the lay-up head 1.

[0060] An electrically conductive molding tool 3 serves as the counter electrode 7 in the exemplary embodiment of FIG. 1, such that a current flow is effected in the semi-finished fiber products between the electrode 6 of the lay-up roll 5 and the electrically conductive tool 3 having its counter electrode 7, said semi-finished fiber products being located between the lay-up roll 5 and the molding tool 3. To this end, the electrode 6 and the counter electrode 7 are connected to an energy source 8 (a voltage source, for example), so as to apply a corresponding voltage to the electrode and/or the counter electrode, in order for the current flow to be effected.

[0061] Moreover, a force F in the direction of the molding tool 3 is applied by the lay-up head 1 and the lay-up roll 5 to the semi-finished fiber products 2 that are laid up or to be laid up during the lay-up process, such that compacting of the electrically conductive fiber material takes place in the region of the lay-up roll 5. On account of the defined compacting in the region of the lay-up roll 5, the semi-finished fiber products, or the fiber material, respectively, that are/is located in this region have/has a lower resistance than the surrounding regions, on account of which the main current flow is correspondingly established. In the exemplary embodiment of FIG. 1, said main current flow is almost perpendicular from the electrode 6 in the direction of the molding tool 3 as the counter electrode 7, this moreover improving the contact between the electrode 6 and the semi-finished fiber product 2.

[0062] In the case of lay-up heads in which the lay-up roll or the lay-up unit 5, respectively, is composed of silicone in order for flexible adapting to unevennesses of the tool to be achieved, the disposal of an electrode on the lay-up roll 5 is most often not expedient. To this end, it is proposed according to the exemplary embodiment of FIG. 2 that an upstream contact installation 9 forms the electrode 6. In the exemplary embodiment of FIG. 2, the contact installation 9 is configured as a roller pair such that a corresponding voltage can be applied both on the one side and on the opposite other side of the planar semi-finished fiber products 2 that are infed to the lay-up head 1. The molding tool also in this case is configured as the counter electrode 7 such that a current flow is effected here from the contact installation 9 up to the contact point between the semi-finished fiber products 2 and the molding tool 3 in the region of the lay-up roll 5.

[0063] The advantage of the exemplary embodiment of FIG. 2 lies in that a comparatively large portion of the semi-finished fiber products 2 is perfused by current such that heating that is more uniform than in the example of FIG. 1 can be expected here.

[0064] Since not every molding tool offers an electrically conductive surface, it is likewise necessary in the context of the invention for the required counter electrode to be provided on or in the lay-up head 1. A corresponding exemplary embodiment is shown in FIG. 3. The lay-up head 1 illustrated therein has two lay-up units 5a and 5b which are sequentially disposed in relation to the infeeding direction D.sub.infeed of the infed semi-finished fiber products 2. It is also conceivable that the lay-up rolls 5a and 5b for a semi-finished fiber product 2 are disposed so as to be substantially beside one another or behind one another.

[0065] In the exemplary embodiment of FIG. 3, the counter electrode 7 is formed by the leading lay-up roll 5a, while the electrode 6 is formed by the trailing lay-up roll 5b. A current flow is effected in that region in which the infed semi-finished fiber products 2 contact the two lay-up rolls 5a and 5b when a corresponding voltage is applied by way of the energy source 8. On account thereof, the semi-finished fiber products, or the electrically conducting fibers of the semi-finished fiber products, respectively, are energized between the contact with the electrode and the counter electrode and thus heated. The lay-up head 1 in the exemplary embodiment of FIG. 4 has two contact installations 9a and 9b which in each case form the electrode 6 and the counter electrode 7, respectively. The contact installations 9a and 9b in FIG. 4 are in each case configured as roller pairs which in each case have two mutually opposite rollers for contacting the semi-finished fiber products 2 and are mutually compressed by way of a defined force such that compacting of the fibers can be achieved. To this end, the semi-finished fiber products are guided through between the two rollers, wherein the rollers (individually or conjointly) exert a force in the direction of the semi-finished fiber products. The semi-finished fiber products 2 are thus in form-fitting contact with the contact installations 9a and 9b such that an adequate electrical contact can be guaranteed.

[0066] The current flow in the semi-finished fiber products 2 is then effected in a portion between the two contact installations 9. The exemplary embodiment of FIG. 4 also has the advantage that no electrically conductive molding tool has to be provided in order for adequate heating to be achieved by energizing the semi-finished fiber products. Furthermore, a separation in terms of the functions of pressing the fiber materials and heating the fiber materials is achieved in this exemplary embodiment, on account of which the most varied materials can be used in principle for the lay-up roll.

[0067] In a manner similar to FIG. 1, FIG. 5 shows a linear heating of the fiber materials 2, in that a contact installation 9a bears in a contacting manner on a first side 2a of the semi-finished fiber products 2, while the second contact installation 9b bears in a contacting manner on a second side 2b of the semi-finished fiber products 2. The contact installation 9a herein is configured as the electrode, while the contact installation 9b is configured as the counter electrode, on account of which a current flow in the bearing region of the semi-finished fiber products 2 is effected in only a linear manner from the first side 2a to the second side 2b.

[0068] Also in the case of this variant, the fiber materials are compacted between the two contact installations 9a and 9b which are configured as rollers, on account of which the current flow is effected in the Z direction of the material, that is to say substantially orthogonal to the plane of the semi-finished fiber products. In order for the energy input to be increased, a connection of roller pairs in series is also conceivable.

[0069] FIG. 6 schematically shows a particular embodiment of a contact roller in cross section, in which a plurality of electrodes 6 and counter electrodes 7 are disposed about the circumference. In the exemplary embodiment of FIG. 6, an electrode and a counter electrode are disposed in an alternating manner on the circumference. Moreover, the electrodes and the counter electrodes are disposed such that they radially project from the contact roller 10 such that, when in contact with a semi-finished fiber product, an additional contact force can be exerted by way of these projecting electrodes and/or counter electrodes.

[0070] Of course, it is also conceivable that the electrodes and/or the counter electrodes of the contact roller 10 terminate so as to be flush with the circumferential face.

LIST OF REFERENCE SIGNS

[0071] 1 Semi-finished fiber product lay-up head [0072] 2 Planar semi-finished fiber products [0073] 2a First side of the semi-finished fiber products [0074] 2b Second side of the semi-finished fiber products [0075] 3 Molding tool [0076] 3a Tool surface [0077] 4 Fiber material infeed [0078] 5 Lay-up unit, lay-up roller [0079] 6 Electrode [0080] 7 Counter electrode [0081] 8 Voltage source [0082] 9, 9a, 9b Contact installations [0083] 10 Contact roller [0084] F Contact pressure force [0085] D.sub.infeed Infeeding direction of the semi-finished fiber products