Method for producing a multilayer fiber composite preform for a fiber composite component

Abstract

A method produces a fiber composite preform for a fiber composite component. The fiber composite preform has a plurality of layers of a fiber roving. The method includes: providing a support core for arranging the fiber roving s on a braiding device, the support core having a support core longitudinal axis, producing a first braided fabric layer from fiber rovings on the support core in a first braiding direction parallel to the support core longitudinal axis of the support core by the braiding device, and producing a second braided fabric layer from fiber rovings on the first braided fabric layer by the braiding device. The second braided fabric layer is produced in a second braiding direction parallel to the support core longitudinal axis, the second braiding direction being opposite the first braiding direction.

Claims

1. A method for producing a fiber composite preform having a plurality of layers of fiber rovings for a fiber composite component, the method comprising: providing a support core for disposing the fiber rovings on a braiding device, wherein the support core has a support core longitudinal axis; generating a first braided fabric layer from fiber rovings on the support core starting from a first end of the support core, in a first braiding direction parallel to the support core longitudinal axis of the support core, by way of the braiding device; and generating a second braided fabric layer from fiber rovings on the first braided fabric layer starting from a second end of the support core opposite the first end, by way of the braiding device, wherein the second braided fabric layer is generated in a second braiding direction parallel to the support core longitudinal axis, wherein the second braiding direction is counter to the first braiding direction, the first braided fabric layer has a first braided fabric layer density profile with a lower first layer density at the first end of the support core than at the second end of the support core, the second braided fabric layer has a second braided fabric layer density profile with a lower second layer density at the second end of the support core than at the first end of the support core, and the first braided fabric layer density profile and the second braided fabric layer density profile are configured such that a total layer density from the first braided fabric layer and the second braided fabric layer is consistent along the support core longitudinal axis core.

2. The method according to claim 1, wherein the providing of the support core is performed by a robotic device.

3. The method according to claim 1, further comprising: after generating the first braided fabric layer and/or after generating the second braided fabric layer, cutting-off projecting fibers of the braided fiber roving by a cutting device.

4. The method according to claim 1, further comprising: rotating the support core by 180° after generating the first braided fabric layer and prior to generating the second braided fabric layer.

5. The method according to claim 1, wherein further braided fabric layers on the support core are generated in a manner analogous to that of the first braided fabric layer and the second braided fabric layer.

6. The method according to claim 1, wherein the support core is configured so as to be mirror-symmetrical about a symmetry plane that is disposed so as to be perpendicular to the support core longitudinal axis.

7. The method according to claim 1, wherein a fiber roving from carbon fibers is used for generating the first and second braided fabric layers.

8. The method according to claim 1, wherein a radial braiding machine is used as the braiding device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a fragment of a support core encased with a first braided fabric layer, in a lateral view.

(2) FIG. 2 shows a fragment of the support core from FIG. 1 after the encasing with a second braided fabric layer, in a lateral view.

(3) FIG. 3 shows a preferred embodiment of the method according to the invention in a sequence diagram.

DETAILED DESCRIPTION OF THE DRAWINGS

(4) Elements with identical functions and operating modes are in each case provided with the same reference signs in FIGS. 1 to 3.

(5) A fragment of a support core 3 that is encased with a first braided fabric layer 5 is schematically depicted in a lateral view in FIG. 1. The support core 3 is configured so as to be rotationally symmetrical about a support core longitudinal axis 4 and has an encircling support core wall 3a which radially surrounds a support core cavity 3b. A first braided fabric layer 5 from fiber rovings 5 is disposed on an external side of the support core 3 or of the support core wall 3a, respectively, that faces away from the support core longitudinal axis 4. The first braided fabric layer 5 by means of the method according to the invention has been generated from a first support core end 3c in a first braiding direction F1 toward a second support core end 3d.

(6) The first braided fabric layer 5 at the first support core end 3c has a low braided fabric density region 8 and in the remaining portion has a high braided fabric density region 7. The low braided fabric density region 8 has a lower braided fabric density than the high braided fabric density region 7. This is due to the first braided fabric layer 5 at the first support core end 3c having been generated as an initial region in which a nominal braided fabric density has not yet been achieved by virtue of technical limitations.

(7) A fragment of the support core 3 from FIG. 1 is schematically illustrated in a lateral view in FIG. 2, wherein a second braided fabric layer 6 from fiber rovings 5 is now disposed on the first braided fabric layer 5. The first braided fabric layer 5 and the second braided fabric layer 6 conjointly form a fiber composite preform 2. The second braided fabric layer 6 by means of the method according to the invention has been generated from the second support core end 3d in a second braiding direction F2, counter to the first braiding direction F1, toward the first support core end 3c.

(8) The second braided fabric layer 6 at the second support core end 3d has the low braided fabric density region 8 and in the remaining portion has a high braided fabric density region 7. This is due to the second braided fabric layer 6 at the second support core end 3d having been generated as an initial region in which a nominal braided fabric density has not yet been achieved by virtue of technical limitations. On account of generating the first braided fabric layer 5 and the second braided fabric layer 6 in such a manner, negative effects of the low braided fabric density region 8 can at least be partially compensated by way of the high braided fabric density region 7 which are in each case adjacent in the radial direction.

(9) FIG. 3 schematically shows a preferred embodiment of the method according to the invention in a sequence diagram. In a first method step 100, a support core 3 that is configured so as to be rotationally symmetrical about a support core longitudinal axis 4 is provided by means of a robotic device and disposed in a starting position on a braiding device.

(10) In a second method step 200, a first braided fabric layer 5 from fiber rovings 1 is generated by means of the braiding device by braiding on the support core 3. The support core 3 and the braiding device herein are displaced in a mutually relative manner in a first braiding direction F1. The first braided fabric layer 5 is thus generated from a first support core end 3c toward a second support core end 3d of the support core and at the first support core end 3c has a lower braided fabric layer density than at the second support core end 3d.

(11) In a third method step 300, the support core 3 is rotated by 180° relative to the braiding device such that the alignments of the first support core end 3c and the second support core end 3d relative to the braiding device are swapped. Alternatively, the same effect can also be achieved by modifying the process management of the braiding device in the braiding process in a corresponding manner.

(12) In a fourth method step 400, a second braided fabric layer 6 is generated by means of the braiding device by braiding on the first braided fabric layer 5. The support core 3 and the braiding device herein are displaced in a mutually relative manner in a second braiding direction F2, counter to the first braiding direction F1. The second braided fabric layer 6 is thus generated from the second support core end 3d toward the first support core end 3c of the support core and at the first support core end 3c has a higher braided fabric layer density than at the second support core end 3d.

(13) In a fifth method step 500, excess fibers by means of a cutting device are cut off from the first braided fabric layer 5 and/or the second braided layer 6. In a sixth method step 600, the fiber composite preform 2 produced according to the invention is removed from the support core 3, for example by destroying the support core in a thermal, chemical, and/or mechanical manner.

LIST OF REFERENCE SIGNS

(14) 1 Fiber roving 2 Fiber composite preform 3 Support core 3a Support core wall 3b Support core cavity 3c First support core end 3d Second support core end 4 Support core longitudinal axis 5 First braided fabric layer 6 Second braided fabric layer 7 High braided fabric density region 8 Low braided fabric density region 100 First method step 200 Second method step 300 Third method step 400 Fourth method step 500 Fifth method step 600 Sixth method step F1 First braiding direction F2 Second braiding direction

(15) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.