DE102013223284A1 - Device for producing a fiber-reinforced plastic component - Google Patents

Abstract

The invention relates to a device for producing a fiber-reinforced plastic component (1) with a forming tool (13) in which a platinum-like, in particular textile semifinished fiber product (3) can be hot-formed, in the electrically conductive reinforcing fibers (5) in a heat-activatable binder (7). embedded, and with an induction heater (19) having at least one inductor (23) for generating an alternating magnetic field, which induces electrical currents in the electrically conductive reinforcing fibers (5) of the semifinished fiber product (3). According to the invention, the inductor (23) is a flat insert part (9) which is separate from the forming tool (13) and can be inserted into the forming tool (13) together with the semi-finished fiber product (3).

Description

The invention relates to a device for producing a fiber-reinforced plastic component according to claim 1, a method according to claim 8 and an insert part for use in the manufacture of the fiber-reinforced plastic component according to claim 9.

For the production of a fiber-reinforced plastic component can be used in current practice, a fiber-reinforced semi-finished fiber whose reinforcing fibers are pre-impregnated in an impregnating incomplete with a binder material. The preimpregnated fiber semi-finished product can be conveyed for further processing in a heating system in which the binder material is heated to a melting temperature. In this state, the fiber-reinforced semi-finished fiber product is subjected to hot working, in which the plastic component is formed. The heating of the semi-finished fiber can be done by induction heating. This is based on the principle that a high-frequency changing magnetic field within an electrically conductive material, that is, the reinforcing fibers in the semifinished fiber product, generates eddy currents. These eddy currents are converted into heat by the internal electrical resistance of the reinforcing fibers.

From the DE 10 2006 040 049 A1 a generic device is known in which a pre-impregnated textile semi-finished fiber product is hot-worked. The semi-finished fiber product has electrically conductive reinforcing fibers (that is to say carbon fibers) which, in the pre-impregnated state, are still incompletely embedded in a heat-activatable binder. For melting the binder, an induction heating is provided, which is constructed of an alternating field generator and an inductor for generating the alternating magnetic field, which induces electrical eddy currents in the electrically conductive reinforcing fibers of the semifinished fiber, which lead to a heating of the reinforcing fibers and as a result of the binder material.

In the DE 10 2006 040 049 A1 the inductor is arranged outside of the forming tool together with the alternator and optionally adjustable along the semi-finished fiber to carry out the heating process. Such induction heating requires high investment costs and is also space-consuming and laborious to use only in use. In addition, the free distance between the inductor and the semi-finished fiber leads to the fact that a higher energy requirement for the induction heating is required.

The object of the invention is to provide a device for producing a fiber-reinforced plastic component, in which the induction heating is easy and flexible to handle and / or the inductor of the induction heating has the lowest possible intrinsic mass.

The object of the invention is solved by the features of claim 1, 8 or 9. Preferred embodiments of the invention are disclosed in the subclaims.

According to the characterizing part of claim 1, in the device according to the invention, the inductor of the induction heating is no longer disposed outside of the forming tool, but rather at least one separate from the forming tool and the semifinished fiber, flat Einlegerteil. The insert part is inserted into the forming tool together with the semifinished fiber product for the hot forming. Compared to the above DE 10 2006 040 049 A1 For example, the inductor embodied as a Einlegererteil can be constructed much cheaper and provide greater energy efficiency with less energy consumption. The inductor may be, for example, a loop of electrically conductive material, such as carbon fibers or a metal wire, such as a copper wire.

A simple and reliable handling of the designed as a separate insert part inductor is of great relevance. Against this background, the insert part can additionally have a carrier layer as a support structure for the inductor. Depending on the intended use, it is important that the insert part of a forming process in the forming tool can follow without damage. Against this background, it is important that the carrier layer, together with the inductor applied to it, is flexible, easy to drape and / or largely limp in comparison with the semifinished fiber product. It is therefore particularly preferred if the carrier layer has a textile base material, that is, a woven or knitted fabric. In this case, the inductor may be fixed to the support layer, for example, by sewing.

To further increase the Drapierfähigkeit the Einlegererteils also the course of the inductor loop can be adjusted. It is particularly preferred if the inductor loop between the connections for the alternator has at least one meandering section which allows a damage-free deformation of the inductor during draping of the insert part.

The Einlegerteil can be inserted together with the semi-finished fiber product in the forming tool to form a two-layer structure. To form the two-layer structure, the Einlegerteil can lie loosely on the semi-finished fiber. alternative For this purpose, it is preferred to secure the position when the insert is fixed by, for example, sewing on the semi-finished fiber.

For a reliable induction heating electrical insulation between the inductor and the electrically conductive reinforcing fibers in the semi-finished fiber is to ensure. For this purpose, by way of example, the inductor can be encased by an insulating material. Alternatively and / or additionally, the carrier layer for the inductor can act as an electrical insulation. In this case, by way of example, the inductor may be arranged on the semi-finished fiber with the interposition of the carrier layer. By way of example, the carrier layer may be a fiberglass fabric.

After the hot-forming process, the insert part having the inductor can remain integrally integrated in the finished fiber-reinforced plastic component. Alternatively, the insert part may also be detached from the fiber-reinforced plastic component after the hot forming process. In this case, the Einlegerteil can be applied with the interposition of an additional Entformungsschicht on the semifinished fiber to allow easy detachment of the Einlegerteils of the finished plastic component.

In one embodiment, the Einlegerteil the semi-finished fiber over a large area, in particular completely cover. As a result, the binder material in the semi-finished fiber can be melted over a large area. Especially with such a large-area design of the inductor, it is advantageous if the carrier layer and / or the inductor is designed sufficiently flexible to follow the shaping in the hot forming tool without damage. The binder material may be thermoplastic or thermosetting.

Depending on the component geometry can be dispensed with such a large-scale melting of the binder material in the semifinished fiber, and instead of the semi-finished fiber are only locally melted. In this case, one or more small inserts parts can be provided, which do not cover the semi-finished fiber product over a large area, but only locally.

During the heating process, if appropriate, the carrier layer can be impregnated by the molten binder material, resulting in a material-locking connection between the insert part and the semifinished fiber product.

Below, the advantages of the invention over the prior art are again listed in a nutshell: Thus, the induction heating according to the invention is very well suited especially for tight radii, as they are often found in the automotive industry. The application for narrow radii is due in particular to the very good formability of the insert part. In addition, the Einlegerteil can be used over a large area or only locally. High heating rates result in efficient temperature control and a short cycle time for binder activation. Especially a flexible and drapable design of the Einlegerteils this can be used variably. This means that different component geometries can be generated in a simple manner. In addition, the induction heating according to the invention is very inexpensive and therefore ideally suited for prototype construction. In comparison to other heating system, such as water or oil lines in the forming tool, the technical complexity and space requirements is extremely low.

The heating process can also be carried out with several stages, so that the Binderaufschmelzprozess can be adapted to the necessary Drapierungsreihenfolge. Finally, a high degree of efficiency is achieved by using an induction heater and additionally by the only occurring in the semifinished fiber heating.

In order to carry out the hot forming process, the insert part according to the invention can be connected, for example, to a vacuum gripper, since the carrier layer (glass fabric) can be designed to be air-permeable. Further connection options are forming tools.

The advantageous embodiments and / or further developments of the invention explained above and / or reproduced in the dependent claims can be used individually or else in any desired combination with one another, for example, in cases of unambiguous dependencies or incompatible alternatives.

The invention and its advantageous embodiments and further developments and advantages thereof are explained in more detail below with reference to drawings.

Show it:

1 and 2 each views illustrating the process steps for producing a fiber-reinforced plastic component;

3 the fiber-reinforced plastic component in a sectional view;

4 in a view from above a Einlegererteil with applied thereto inductor; and

5 a fiber-reinforced plastic component according to a second embodiment.

Based on 1 to 3 First, the method for producing a fiber-reinforced plastic component 1 ( 3 ). All figures are made with a view to a simpler understanding of the invention. Therefore, the figures are only roughly simplified schematic diagrams that no realistic layer structure of the plastic component 1 play.

So be first according to the 1 a platinenartiges, textile semi-finished fiber 3 as well as an insert part 9 provided as separate components. The semifinished fiber product 3 comprises a preimpregnated fabric of a warp and weft yarn system made of electrically conductive reinforcing fibers 3 consists. For the formation of the semifinished fiber product 3 the fabric is not fully wetted with a binder, for example made of a thermoplastic, in an impregnating plant, not shown. The insert part 9 is from a carrier layer described later 25 and an inductor 23 built, the part of an induction heating 19 is.

Like from the 1 shows, the Einlegererteil 9 on the semi-finished fiber 3 to form a two-layer structure 10 applied. In addition, the Einlegerteil 9 according to the 1 by indicated auxiliary seams 11 positionally pre-positioned. Subsequently, the two-layer structure 10 , consisting of the semifinished fiber product 3 and the insert part 9 in a hot forming tool 13 positioned. The hot forming tool 13 according to the 2 an upper forming tool 15 and a lower forming tool 17 which is exemplified by a milled polymer block.

To prepare the hot forming then the two-layer construction 10 via the induction heating 19 heated up in the 1 or 2 an alternator 21 as well as the inductor 23 having. The inductor 23 is not outside the hot stamping tool 13 positioned but in the insert part 9 integrated. During the heating process, the inductor generates 23 an alternating magnetic field in the electrically conductive reinforcing fibers 5 of the semifinished fiber product 3 induced electrical currents, resulting in a heating of the reinforcing fibers 5 and in the wake of the binder 7 to lead. The binder material is heated to its melting temperature, whereby the reinforcing fibers 5 be completely wetted with the binder material and the semi-finished fiber 3 consolidated. Then the shaping takes place, in which the preheated fiber semi-finished product 3 under pressure from the upper die 15 to the fiber reinforced plastic component 1 is formed.

In the 4 is the insert part 9 shown in a unique position. The insert part 9 has as support structure for the inductor 23 the already mentioned carrier layer 25 on, which is an example of an electrically insulating glass fabric here. The inductor 23 is in the 4 a loop whose connecting ends 27 in contact with the alternator 21 can be brought. To provide sufficient flexibility and Drapierfähigkeit the Einlegererteils 9 to ensure the course of the inductor loop meandering, which can be compensated without damage during shaping resulting position changes. The inductor loop can be made by auxiliary seams 26 (only in the 2 indicated) on the carrier layer 25 be applied. The inductor 23 can be constructed of any conductive material. By way of example, the inductor 23 electrically conductive fibers 33 or alternatively a metal wire.

The conductive material of the inductor 23 electrically isolated from the likewise conductive reinforcing fibers 5 (For example, carbon fibers) of the semi-finished fiber 3 to arrange. For such electrical insulation, the inductor 23 optionally have a cable sheath. Optionally, the carrier layer 25 even as an electrical insulation between the inductor 23 and the reinforcing fibers 5 of the semifinished fiber product 3 Act.

During the hot forming process, the fabric may be the backing layer 25 of the insert part 9 also from the melted binder material 7 be at least partially saturated. In this way, results in a total one-piece composite, in which the inductor 23 and the carrier layer 25 in the plastic component 1 are integrated.

In the 1 to 4 is the insert part 9 executed over a large area, in such a way that the semi-finished fiber 3 completely covered. In this way, takes place during the heating process, a large-scale melting of the entire binder material 7 in semi-finished fiber 3 ,

Depending on the component geometry, instead of a large-scale insert part 9 also one or more smaller inserts parts 9 Use, with which only in local areas of the semifinished fiber product 3 the binder material 7 is melted. So is in the 5 an example of a fiber-reinforced plastic component 1 with a floor 38 as well as raised side walls 39 shown, which together form an inside corner area. In contrast to the previous embodiment are in, in the 5 shown fiber-reinforced plastic component 1 two loop-type inductors 23 integrated, spaced from each other in the plastic component 1 are integrated. The two loop-type inductors 23 extend contour-matched between the ground 38 and the side walls 39 of the plastic component 1 ,

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

• DE 102006040049 A1 [0003, 0004, 0007]

Claims (9)

Device for producing a fiber-reinforced plastic component ( 1 ), with a forming tool ( 13 ), in which a platinum-like, in particular textile semi-finished fiber product ( 3 ) is thermoformable, in the electrically conductive reinforcing fibers ( 5 ) in a heat-activated binder ( 7 ) and with induction heating ( 19 ), which has at least one inductor ( 23 ) for generating an alternating magnetic field which in the electrically conductive reinforcing fibers ( 5 ) of the semifinished fiber product ( 3 ) induces electrical currents, characterized in that the inductor ( 23 ) at least one of the forming tool ( 13 ) separate, flat insert part ( 9 ), which together with the semi-finished fiber product ( 3 ) in the forming tool ( 13 ) can be inserted. Device according to claim 1, characterized in that the inductor ( 23 ) is at least one loop of electrically conductive material, such as carbon fibers or a metal wire, is. Device according to claim 1 or 2, characterized in that the insert part ( 9 ) as a support structure for the inductor ( 23 ) a carrier layer ( 25 ), and in particular that the carrier layer ( 25 ) has a textile base material, such as a woven or a knitted fabric, and / or that the inductor ( 23 ), in particular by sewing, on the carrier layer ( 25 ) is fixed. Device according to claim 1, 2 or 3, characterized in that the insert part ( 9 ) to form a two-layer structure ( 10 ) together with the semi-finished fiber product ( 3 ) in the forming tool ( 13 ) and that in particular the insert part ( 9 ) to form the two-layer structure ( 10 ) loosely on the semifinished fiber product ( 3 ) or fixed thereon by, for example, sewing. Device according to one of the preceding claims, characterized in that the inductor ( 23 ) compared to the electrically conductive reinforcing fibers ( 5 ) of the semifinished fiber product ( 3 ) is electrically isolated, and that in particular for the electrical insulation of the inductor ( 23 ) is encased by an insulating material, and / or that the carrier layer ( 25 ) forms the electrical insulation, and / or that the inductor ( 23 ) with interposition of the carrier layer ( 25 ) on the semifinished fiber product ( 3 ) is arranged. Device according to one of the preceding claims, characterized in that the inductor ( 23 ) after completion of the fiber-reinforced plastic component ( 1 ) in one piece in the plastic component ( 1 ) remains integrated. Device according to one of the preceding claims, characterized in that the insert part ( 9 ) the semi-finished fiber product ( 3 ) over a large area, in particular completely covered, and indeed for a large-area melting of the binder material ( 7 ) in the semi-finished fiber product ( 3 ), or that the insert part ( 9 ) For a local melting only covers at least a portion of the semifinished fiber product. Process for producing a fiber-reinforced plastic component ( 1 ) with a device according to one of the preceding claims, in which a semi-finished fiber product ( 3 ) comprising electrically conductive reinforcing fibers which are contained in a heat-activatable binder (US Pat. 7 ) are embedded, in a heating process, the semifinished fiber product by an induction heating ( 19 ) is heated at least locally, and in a hot forming a shaping of the semifinished fiber product ( 3 ), characterized in that for carrying out the heating process, the inductor ( 23 ) of induction heating ( 19 ) before the heating process on the semifinished fiber product ( 3 ) is applied. Insertion part for a device according to one of claims 1 to 7, which together with the semifinished fiber product ( 3 ) for shaping into a hot forming tool ( 13 ), characterized in that the insert part ( 9 ) an inductor ( 23 ), which is part of an induction heater ( 19 ) for heating the semifinished fiber product ( 3 ).

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