Multi-Layer Pre-Fabricated Covering Device

Abstract

A covering device for a component space in a tool for producing fiber composite components is a multi-layer pre-fabricated material cloth provided with a gas-permeable, matrix material-impermeable membrane. A gas-impermeable, matrix material-impermeable film is provided. Membrane and film are connected at their circumferential rims to delimit an evacuation space with a flow aid and closed by a matrix material-tight connection. Gas having passed from the component space through the membrane into the evacuation space is evacuated through an opening of the film away from the component space. A contact element arranged at a side of the film facing away from the evacuation space surrounds the opening of the film. It is connected matrix material-tightly to the film. The contact element has a contact surface at a side facing away from the film for attaching the covering device to an inner side of a tool wall delimiting the component space.

Claims

1. A covering device for covering a component space in a tool for producing a fiber composite component, wherein the covering device is a multi-layer pre-fabricated material cloth comprising: a membrane that is gas-permeable but matrix material-impermeable and comprises a circumferential rim; a film that is gas-impermeable and matrix material-impermeable and comprises a circumferential rim, wherein the membrane and the film are connected to each other at the circumferential rims to delimit an evacuation space closed at the circumferential rims by an at least matrix material-tight connection, wherein the evacuation space is configured to evacuate a gas, having passed from the component space of the tool into the evacuation space through the membrane, from the evacuation space in a direction away from the component space of the tool through an opening of the film; a layer of a flow aid arranged in the evacuation space between the membrane and the film; a contact element arranged at a side of the film facing away from the evacuation space, wherein the contact element surrounds the opening of the film and is connected at least matrix material-tightly to the film; wherein the contact element comprises a contact surface at a side of the contact element facing away from the film, wherein the contact surface is configured to attach the covering device to an inner side of a tool wall of the tool delimiting the component space.

2. The covering device according to claim 1, further comprising an adhesive layer disposed on the contact surface and configured to fix the covering device to the inner side of the tool wall delimiting the component space.

3. The covering device according to claim 2, wherein the adhesive layer is provided with a peel-off film that is not sticky outwardly.

4. The covering device according to claim 2, wherein the adhesive layer and the contact surface are embodied to produce an at least matrix material-tight contact on the inner side of the tool wall delimiting the component space.

5. The covering device according to claim 1, wherein the opening of the film is of a round configuration and the contact surface surrounding the opening of the film is of a round configuration.

6. The covering device according to claim 1, wherein the contact surface comprises a width in a radial direction away from a center of the opening of the film and wherein the width corresponds to at least one fourth of a diameter of the opening of the film.

7. The covering device according to claim 1, wherein the membrane and the film are thermally welded to each other at the circumferential rims.

8. The covering device according to claim 1, wherein the contact element is comprised of a butyl rubber with the contact surface having a closed embodiment.

9. The covering device according to claim 1, wherein the covering device has a planar surface of a size surpassing more than fivefold a cross section surface area of the opening of the film.

10. A method for sealing a venting opening in a tool for producing a fiber composite component, comprising: arranging a covering device according to claim 1 at the venting opening to seal against ingress of matrix material into the venting opening.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0026] The invention will now be explained in more detail with the aid of a preferred embodiment as well as with reference to the attached drawing.

[0027] FIG. 1 shows a cross section of a covering device arranged in a component space of a tool for producing a fiber composite component.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0028] FIG. 1 shows a cross section of a covering device 2 which is arranged in the component space 26 of a tool. The covering device 2 comprises at one side the membrane 4 and at the other side the film 6. The membrane 4 and the film 6 bound the evacuation space 8, provided with a flow aid 10, through which the gas, sucked through the membrane 4 from the component space 26, flows in the direction toward the opening 14. In order to prevent ingress of matrix material into the evacuation space 8, the membrane 4 and the film 6 are connected to each other at least matrix material-tightly in the region of the circumferential rims 12.

[0029] At the side of the covering device 2 which is facing away from the component space 26, a contact element 16 is placed onto the exterior side of the film 6 in the region of the opening 14. With the contact surface 18 formed at the contact element 16, the covering device 2 can be attached in the region of the venting opening 32 to the inner side 24 of the tool wall 22. In order to improve adhesion of the covering device 2 at the tool wall 22, at the contact surface 18 an adhesive layer 20 can be arranged by means of which the covering device 2 is glued to the tool wall 22.

[0030] In the attached FIG. 1, the covering device 2 is not yet fastened to the tool wall 22. In order to fasten the covering device 2 to the tool wall 22, it must be pushed in the direction of the two arrows via the contact surface 18 onto the tool wall 22. Thereafter, it is at least material-tightly connected to the inner side 24 of the tool wall 22. As can be seen in FIG. 1, the diameter of the opening 14 and of the venting opening 32 do not precisely match. The dimensional differences are however compensated by the width of the contact surface 18 so that a covering device 2 with an opening 14 whose diameter is smaller than the diameter of the venting opening 32 nonetheless can be used for sealing such a venting opening.

[0031] In the embodiment illustrated in FIG. 1, the tool is comprised of a first part 28 that bounds the bottom part of the component space 26 and a second part 30 that covers the component space 26 in upward direction. Preferably, the layers of the fibers that reinforce the finished component are placed into the first part 28 prior to the component space 26 being closed and being flooded with matrix material, for example, by means of the vacuum infusion method. When the parts 28, 30 are placed on each other, the component space 26 is closed. After closing of the tool, the component space 26 is evacuated by a vacuum that is applied to the venting opening 32. For reasons of simplification, the vacuum pump with its corresponding hose conduits as well as the tank and the supply line for supplying the matrix material are not illustrated in FIG. 1.

[0032] Finally, it should be noted that the size of the covering device 2 illustrated in FIG. 1 as well as of its components in relation to the venting opening 32, the tool as a whole, and the size ratio of the individual components of the covering device 2 relative to each other as well as the shape, arrangement, and dimensions of the individual components may deviate from the illustrated embodiment.

[0033] The invention is not limited to the afore described embodiments. A person of skill in the art will have no difficulties to modify the embodiments in a manner that appears suitable to him in order to adapt them to a concrete application situation.

[0034] The specification incorporates by reference the entire disclosure of German priority document 10 2021 109 829.7 having a filing date of Apr. 19, 2021.

[0035] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

LIST OF REFERENCE CHARACTERS

[0036] 2 covering device [0037] 4 membrane [0038] 6 film [0039] 8 evacuation space [0040] 10 flow aid [0041] 12 circumferential rim [0042] 14 opening [0043] 16 contact element [0044] 18 contact surface [0045] 20 adhesive layer [0046] 22 tool wall [0047] 24 inner side [0048] 26 component space [0049] 28 first part of tool [0050] 30 second part of tool [0051] 32 venting opening