Method and tool system for manufacturing a component from a fiber-reinforced plastic

Abstract

A method for producing a component from a fiber-reinforced plastic, wherein at least one ply of a semifinished fiber product having a peripheral contour is applied to the molding tool at a first temperature, wherein the contour lies within the peripheral edge. A compensating body, having a coefficient of thermal expansion which is greater than a coefficient of thermal expansion of the molding tool, is arranged along the peripheral edge, such that the compensating body extends from the edge in the direction of the peripheral contour. After sealing the arrangement, resin is introduced, and the arrangement is heated. As a result, the compensating body expands to a greater extent than the molding tool and encloses the semifinished fiber product in a flush manner, with the result that a shape of the component can correspond to an intended final shape and no longer has to be finish-machined.

Claims

1. A method for producing a component from a fiber-reinforced plastic, comprising: providing a molding tool with a tool surface having a peripheral edge; positioning at least one ply of a semifinished fiber product, having a peripheral contour which lies within the peripheral edge, on the tool surface at a first temperature; arranging a compensating body, having a coefficient of thermal expansion which is greater than a coefficient of thermal expansion of the molding tool, along the peripheral edge, such that the compensating body extends from the edge in a direction of the peripheral contour; sealing an arrangement of the at least one ply and of the compensating body by a closure device to form a closed mold; heating the mold, such that the compensating body expands to a greater extent than the mold; introducing resin into the mold; and curing, cooling, and removing the component; wherein the compensating body is narrower at longitudinal edges than at transverse edges of the molding tool before being arranged on the molding tool.

2. The method of claim 1, wherein heating the mold comprises: heating the mold from the first temperature to a second temperature at which the compensating body expands to an extent that exceeds expansion of the mold by an amount such that the compensating body partially fills an interspace formed between the peripheral contour and the peripheral edge; and wherein curing the component comprises: heating the mold from the second temperature to a limit temperature at which the resin initiates crosslinking in the semifinished fiber product and the compensating body further expands to an extent that exceeds further expansion of the mold such that the compensating body exactly fills the interspace; and heating the mold from the limit temperature to a third temperature at which curing of the resin is completed.

3. The method of claim 2, wherein the second temperature is in a range of from 70 C. to 150 C.

4. The method of claim 3, wherein the third temperature is in a range of from 150 C. to 220 C.

5. The method of claim 1, wherein the molding tool has a coefficient of thermal expansion of at most 30.Math.10.sup.6 K.sup.1, and the compensating body has a coefficient of thermal expansion of at least 100.Math.10.sup.6 K.sup.1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features, advantages and possible applications of the disclosure herein will be found in the following description of the example embodiments and the figures. In this context, all the features described and/or illustrated graphically form the subject matter of the disclosure herein in themselves and in any desired combination, irrespective of their combination in the individual claims or the dependency references thereof. In the figures, the same reference signs are furthermore used for identical or similar objects.

(2) FIG. 1 shows a schematic block-based illustration of a method.

(3) FIGS. 2A, 2B and 2C show a tool system in several three-dimensional views.

(4) FIGS. 3A, 3B, 3C and 3D show details of compensating bodies in the molding tool.

DETAILED DESCRIPTION

(5) FIG. 1 shows a schematic block-based illustration of a method 2 according to the disclosure herein for producing a component from a fiber-reinforced plastic. The method 2 has the steps of providing 4 a molding tool with a tool surface having a peripheral edge, of positioning 6 at least one ply of a fiber tool, having a peripheral contour which lies within the peripheral edge, on the tool surface at a first temperature, of arranging 8 a compensating body, having a coefficient of thermal expansion which is greater than a coefficient of thermal expansion of the molding tool, along the peripheral edge, such that the compensating body extends from the edge in the direction of the peripheral contour. Subsequently, the sealing 10 of the arrangement of the at least one ply and of the compensating body by a closure device to form a closed mold, the heating 12 of the mold, with the result that the compensating body expands to a greater extent than the mold, the introduction 14 of resin into the mold, curing 16, cooling 18, and removal 20 are performed. Heating may comprise heating to a second temperature, which may be in a range of from 90 C. to 150 C. After introduction 16, heating 22 to a third temperature in a range of from 150 C. to 200 C. can be provided for the purpose of curing 18.

(6) FIG. 2A shows, in a very schematic illustration, a tool system 24 according to the disclosure herein, which makes possible the method 2 illustrated above. The tool system 24 has a molding tool 26 with a tool surface 28, which has a peripheral edge 30. In addition, a plurality of compensating bodies 32, which, by way of example, are shaped in the manner of strips, are provided. While the molding tool 26 could be produced from aluminum, for example, the compensating bodies 32 preferably comprise a plastics material, such as PTFE, for example, or a rubber material. The material of the compensating bodies 32 could be rigid or flexible. The use of a flexible material could facilitate automated application if this is desired. According to the disclosure herein, the coefficient of thermal expansion of the compensating body 32 is significantly higher than that of the molding tool 26.

(7) Furthermore, a closure device 34 is provided, which is designed to be complementary to the molding tool 26. The closure device 34 can be pressed onto the molding tool 26 by a screw connection or an external movement or holding device. A heating device 36 is shown merely as a reference sign under the molding tool 26. The heating device 36 could be provided both in the molding tool 26 and in the closure device 34, in both of these elements or externally thereto, and serves for heating the molding tool 26 as required.

(8) The tool surface 28 is designed to receive a ply of a semifinished fiber product 38 at a first temperature, which is, for example, room temperature (approximately 20 C.). This has a peripheral contour 40. When the semifinished fiber product 38 lies on the tool surface 28, the peripheral contour 40 lies within the peripheral edge 30, and consequently there is a gap. The compensating bodies 32 then rest on the molding tool on the tool surface 28 and preferably adjoin the edge 30 in a flush manner.

(9) The closure device 34 is furthermore designed to close the molding tool 26 to form a closed mold 42 (see FIG. 2C), and in the process to enclose both the semifinished fiber product 38 and the compensating bodies 32 and absorb the process forces. The latter result from a resin pressure and a thermal expansion pressure. Thereafter, resin can be introduced into the mold 42 via certain resin inlets 44, thus infiltrating the semifinished fiber product 38.

(10) As illustrated above, particular attention is paid to the coefficient of thermal expansion of the molding tool 26 and of the compensating bodies 32. This becomes particularly clear from the further illustrations.

(11) FIG. 3A, for instance, shows the molding tool 26 with the semifinished fiber product 38 located thereon and a compensating body 32, which is arranged on the peripheral edge 30 and extends in the direction of the peripheral contour 40 of the semifinished fiber product 38. This could be, for example, a wing shell which has an elongate shape.

(12) In FIG. 3B, the molding tool 26 is shown in a partial view I at the first temperature, at which the semifinished fiber product 38 is laid on the tool surface 28. Here, the compensating body 32 is in a state of low expansion. In partial illustration II, the molding tool 26 has been brought to the second or third temperature, the compensating body 32 already being significantly expanded.

(13) FIG. 3C shows a detail of the molding tool 26, the compensating body 32, the semifinished fiber product 38, and the tool surface 28. This surface is visible at the first temperature in the form of a gap 46. The gap 46 will also occur after cooling and facilitate the removal of the finished component from the molding tool 26. At least during the third temperature, but optionally also during the second temperature, the compensating body 32 could be expanded to such an extent that the gap 46 is closed and thus dimensional accuracy of the semifinished fiber product 38 is made easier.

(14) In addition, it should be noted that having does not exclude other elements or steps and a or an does not exclude a multiplicity. Furthermore, it should be noted that features which have been described with reference to one of the above example embodiments can also be used in combination with other features of other example embodiments described above. Reference signs in the claims are not to be regarded as a restriction.

(15) While at least one example embodiment of the invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the example embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a, an or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

REFERENCE SIGNS

(16) 2 method 4 providing 6 positioning 8 arranging 10 sealing 12 heating (to a second temperature) 14 introducing 16 curing 18 cooling 20 removing 22 heating (to a third temperature) 24 tool system 26 molding tool 28 tool surface 30 peripheral edge 32 compensating body 34 closure device 36 heating device 38 semifinished fiber product 40 peripheral contour 42 mold 44 resin inlet 46 gap