Verfahren zum Herstellen eines Faserverbund-Hohlbauteils und Faserverbund-Hohlbauteil

Abstract

The invention relates to a method for producing a fiber-composite hollow component from a fiber-composite material which contains at least one fibrous material and one matrix material, wherein the fiber-composite hollow component is formed from at least two fiber-composite half-shells which in a joining edge region of the fiber-composite half-shells are joined to one another such that a cavity is configured between the joined-together fiber-composite half-shells, wherein the method comprises the following steps: providing a first fiber-composite half-shell formed from the fibrous material of the fiber-composite material, and at least one second fiber-composite half-shell formed from the fibrous material of the fiber-composite material; assembling the first fiber-composite half-shell and the at least second fiber-composite half-shell so as to form the fiber-composite hollow component; wherein at least one spacer element is inserted in the joining edge region between the first fiber-composite half-shell and the at least second fiber-composite half-shell; incorporating an internal vacuum cover in the cavity formed by the assembling of the fiber-composite half-shells, and incorporating the assembled fiber-composite half-shells in an external vacuum cover such that a component cavity having the fibrous material of the fiber-composite hollow component to be produced is formed between the internal vacuum cover and the external vacuum cover; evacuating the component cavity having the fibrous material; and curing the matrix material which embeds the fibrous material of the fiber-composite half-shells, in order for the fiber-composite hollow component to be produced.

Claims

1. A method for producing a fiber-composite hollow component from a fiber-composite material which contains at least one fibrous material and one matrix material, wherein the fiber-composite hollow component is formed from at least two fiber-composite half-shells which are joined to one another in joining edge regions of each of the two fiber-composite half-shells such that a cavity is configured between the two fiber-composite half-shells when they are joined together, comprising: providing a first fiber-composite half-shell and at least one second fiber-composite half-shell, each of which are formed from the fiber-composite material; assembling the first fiber-composite half-shell and the at least second fiber-composite half-shell so as to form the fiber-composite hollow component wherein at least one spacer element is inserted in the joining edge region between the first fiber-composite half-shell and the at least one second fiber-composite half-shell; incorporating an internal vacuum cover in the cavity of the fiber-composite hollow component formed by the assembling step, and incorporating the fiber-composite hollow component formed by the assembling step in an external vacuum cover such that a component cavity having the fibrous material of the fiber-composite hollow component to be produced is formed between an internal vacuum cover and the external vacuum cover; evacuating the component cavity having the fibrous material; and curing the matrix material which embeds the fibrous material of the fiber-composite half-shells.

2. The method of claim 1 wherein each of the fiber-composite half-shells provided in the providing step have a convexly curved primary shell region such that a concavely curved transition region is formed at by the joining edge regions on two opposite sides.

3. The method of claim wherein the at least one spacer element is/are formed from a fibrous material of a fiber-composite material and the at least one spacer element is/are inserted in the joining edge region, wherein the matrix material embedding the fibrous material of the fiber-composite half-shells and the fibrous material of the at least one spacer element is cured in one process step.

4. The method of claim 1 wherein at least one of the fiber-composite half-shells is provided by incorporating the fibrous material in a molding tool.

5. The method of claim 1 wherein the first fiber-composite half-shell is provided by incorporating the fibrous material in a first molding-tool half of a molding tool, and the at least one second fiber-composite half-shell is provided by incorporating the fibrous material in a second molding-tool half of the molding tool; wherein the at least one spacer element in the joint regions is/are subsequently deposited on the fibrous material of the first fiber-composite half-shell in the first molding-tool half, and/or on the fibrous material of the second fiber-composite half-shell in the second molding-tool half; and wherein the first molding tool half and the second molding tool half are subsequently closed such that the first fiber-composite half-shell and the at least one second fiber-composite half-shell are connected to one another by way of the at least one spacer element.

6. The method of claim 5, wherein the internal vacuum cover is sealed in a vacuum-tight manner in relation to the molding tool, and wherein the external vacuum cover is formed by the molding tool when closed.

7. The method of claim 5 wherein the molding tool, when closed, is incorporated in the external vacuum cover and, with the internal vacuum cover, is sealed in a vacuum-tight manner such that the component cavity is formed between the internal vacuum cover and the external vacuum cover.

8. The method according to claim 1 wherein a shell mast is produced as the fiber-composite hollow component.

9. The method according to claim 1, wherein the internal vacuum cover delimits the component cavity in relation to an external region, and wherein the external region in relation to an ambient pressure is impinged with a positive pressure.

10. A fiber-composite hollow-component formed by the method of claim 1.

11. The fiber-composite hollow component according to claim 10 configured as a shell mast (10).

12. The fiber-composite hollow component according to claim 11, wherein the shell mast is a roll-up capable shell mast.

Description

[0037] The invention will be explained in an exemplary manner by means of the appended figures in which:

[0038] FIG. 1 shows a schematic cross-sectional illustration of a roll-up capable shell mast; and

[0039] FIG. 2 shows a schematic cross-sectional illustration in the production of such a shell mast with the aid of a molding tool.

[0040] FIG. 1 schematically shows the shell mast 10 which is produced from a fiber-composite material having fibrous material and matrix material. The shell mast 10 herein is produced from a first fiber-composite half-shell 11 and from a second fiber-composite half-shell 12. The two half-shells herein are joined to one another and herein produced in a single process step which includes the curing of the matrix material of the half-shells 11 and 12 as well as of the joint.

[0041] The fiber-composite half-shells 11 and 12 in the peripheral regions thereof have in each case joining edge regions 13 in which the first fiber-composite half-shell 11 is joined to the second fiber-composite half-shell 12. To this end, a spacer element 14 is in each case situated in the joining edge region 13 between the first fiber-composite half-shell 11 and the second fiber-composite half-shell 12, on account of which the first half-shell 11 is held in a defined manner at a predefined spacing from the second half-shell 12.

[0042] The half-shells 11 and 12 have in each case one convexly curved primary shell region 15 which on both sides of the cross section in each case are joined by a concavely curved transition region 16 which finally opens into the joint region 13. On account of the spacer element 14 it is prevented herein that the transition regions 16 of the first half-shell 11 and the transition region 16 of the second half-shell 12 converge in the common joint region 13 and a sharp gusset region which facilitates resin accumulations is thus formed. Rather, this tangential convergence of the transition regions 16 is interrupted by the spacer element 14, on account of which respective gusset regions are avoided.

[0043] FIG. 2 shows the production of such a shell mast 10, known from FIG. 1, with the aid of a molding tool 20. The molding tool 20 herein has a first molding-tool half 21 and a second molding-tool half 22 which in each case has a respective shape-imparting tool surface in such a manner that a corresponding half-shell 11 and 12 can be produced with the aid of each molding-tool half 21 and 22.

[0044] The molding tool 20 herein is configured such that said molding tool 20 can be transferred from an open state to a closed state, wherein fibrous material is first incorporated in the opened molding-tool halves 21 and 22 in the open state. The respective half-shell 11 and 12 is formed on account of the incorporation of the fibrous materials.

[0045] The spacer element 14 is subsequently placed on the first and/or the second half-shell such that the molding-tool halves 21 and 22 can thereafter be closed. In the closing of the molding-tool halves, the half-shells 11 and 12 contact one another in the joint region in the respective molding-tool halves, specifically by way of the spacer element 14 that is incorporated therein.

[0046] Before closing, or after closing, an internal vacuum cover 23 is incorporated in the formed cavity 17 of the shell mast 10 herein such that the internal wall of the cavity 17 is covered by such an internal vacuum cover 23. The entire molding tool 20, having the closed molding-tool halves 21 and 22 thereof, is thereafter incorporated in an external vacuum cover 24, wherein the internal vacuum cover 23 and the external vacuum cover 24 are then mutually sealed such that a vacuum-tight component cavity 25 is created between the internal vacuum cover 23 and the external vacuum cover 24.

[0047] On account of the evacuation of the component cavity 25, the molding tool and the molding-tool halves 21 and 22 thereof are compressed by virtue of the external environmental pressure, for example the atmospheric pressure P.sub.a, or of a positive pressure, while the half-shells 11 and 12 are pushed from the inside against this shape-imparting tool surface of the respective molding-tool halves. This is indicated by the respective arrows.

[0048] As can be seen in the enlargement of the gusset region, the internal vacuum cover herein not only hugs the first half-shell 11 and the second half-shell 12 from the inside, but also hugs the end side of the spacer element 14, such that any gusset formation is avoided in this region. No resin accumulations can thus be created in said regions when a matrix material is infused into the dry fibrous material, or no resins or matrix material, respectively, can leak at this location when the component is evacuated. A shell mast which has defined spacing and which avoids resin accumulations in small micro-cavities of this type is thus ultimately created.

[0049] On account of the internal vacuum cover 23 and the external vacuum cover 24, the component cavity 25 is delimited from an external region 26 such that the component cavity 25 is evacuatable. The interior cavity 27 formed by the internal vacuum cover 23 herein can also be a component part of the external region 26.

[0050] By contrast, said interior cavity of the internal vacuum cover 23 in the exemplary embodiment of FIG. 2 is closed such that said interior cavity is capable of being impinged with an additional pressure. This pressure is identified as P.sub.a and is higher than the pressure P.sub.a. It can be achieved on account thereof that the internal vacuum cover 23 is correspondingly pressed against the fibrous material of the half-shells 11 and 12 that is incorporated in the component cavity 25 in a correspondingly more intense manner than under the normal atmospheric pressure.

[0051] The method according to the invention is thus suitable for the production of double-omega-shaped shell masts which are in particular intended to be roll-up capable. Shell masts produced by said method are thus particularly suitable for aerospace structures that are capable of unfolding, inter alia solar sails, photovoltaics applications that are capable of unfolding, antennae, instrument masts, de-orbit sails, etc.

LIST OF REFERENCE SIGNS

[0052] 10Shell mast

[0053] 11First fiber-composite half-shell

[0054] 12Second fiber-composite half-shell

[0055] 13Joint region

[0056] 14Spacer element

[0057] 15Convexly curved primary shell region

[0058] 16Concavely curved transition region

[0059] 17Cavity

[0060] 20Molding tool

[0061] 21First molding-tool half

[0062] 22Second molding-tool half

[0063] 23Internal vacuum cover

[0064] 24External vacuum cover

[0065] 25Component cavity

[0066] 26External region

[0067] 27Interior cavity of the internal vacuum cover

[0068] P.sub.aAtmospheric pressure

[0069] P.sub.aPositive pressure