FIBER COMPONENT WITH FIBER RODS CONNECTED TO A TRUSS

Description

[0001] The invention relates to a fiber component consisting of fiber rods connected to form a framework.

[0002] Fiber rods are used in fiber composite components and differ from fiber layers in that they are formed by a large number of continuous fibers, i.e., they are formed into a predetermined rod shape by the fibers. The cross-sectional shape of the rods is usually round, square, or hexagonal with a height-to-width ratio of greater than or equal to 1 / 10. Lower height-to-width ratios are not considered shaped fiber rods.

[0003] Fiber-reinforced plastics have a high potential for lightweight construction and, compared to other materials such as metals or unreinforced plastics, can absorb high tensile forces thanks to the fibers incorporated into them. The weight-specific advantages of fiber-reinforced plastics are best utilized when the fibers in the matrix material are designed to accommodate the load path, which requires a load-adapted design of the material. Therefore, it is desirable to be able to use fiber rods not only in one load direction, but also to be able to implement changes in the direction of fiber rods within a lattice structure to ensure a multiaxially loaded component.

[0004] From the documents EP 0 009 403 A1, GB 1 305 198 A and US 6 299 246 B1, various fiber components are already known, each of which has a truss-like structure formed from fiber rods.

[0005] The invention is therefore based on the object of providing a fiber component that can be manufactured inexpensively and energy-efficiently, is very lightweight, and can accommodate load paths in different directions. Furthermore, the object of the invention is to provide a method for the inexpensive and energy-efficient production of such a fiber component.

[0006] This object is achieved by the combination of features according to patent claim 1.

[0007] According to the invention, a fiber component comprising at least three fiber rods is proposed. The at least three fiber rods each comprise fibers extending continuously in the axial direction of the fiber rods. At least two of the three fiber rods each form a support rod and at least one of the three fiber rods each forms a connecting rod. The support rods are arranged essentially parallel and spaced apart from one another in their axial direction. The connecting rod connects the support rods to one another and forms a node with the respective support rod at the respective connection points between the connecting rod and the support rods. A fiber component is also to be understood here as a fiber composite component, wherein the fibers or the fiber rods are impregnated with a matrix, such that the matrix is ​​formed in and on the fiber rods.The matrix can also be formed to extend between the fiber rods, so that the matrix fills the volume between the fiber rods. A connection point or connecting section is located between a connecting rod and a support rod at the point where the connecting rod abuts the support rod to connect the connecting rod to the support rod.

[0008] A design variant is advantageous in which at least three of the at least three fiber rods form a truss structure through their arrangement with one another.

[0009] According to the invention, at least three fiber rods each form a support rod. The support rods are arranged essentially parallel to one another in their axial direction X and lie on at least two spaced-apart planes, so that they form an imaginary volume between them. At least one connecting rod is wound around the support rods forming the imaginary volume and connects the support rods to one another. The at least one connecting rod forms the nodes with the support rods forming the volume at its connection points with the support rods forming the imaginary volume.

[0010] In an advantageous further development, the at least one connecting rod or rods form or form a space framework with the support rods forming the imaginary volume due to their arrangement relative to one another.

[0011] The fiber rods are arranged in a lattice structure, whereby the lattice structure is designed in the form of a truss or space frame, whereby the fiber rods that form the truss are subjected exclusively to normal forces, i.e. forces along the longitudinal axis of the fiber rods.

[0012] A further advantageous embodiment is one in which the fiber component is a support whose side surfaces consist at least partially of the at least three fiber rods arranged in the truss structure or in the plurality of truss structures.

[0013] Furthermore, in one embodiment, it is advantageous that the support is determined by the fiber rods or support rods forming the volume and the side surfaces are each located between two of the parallel fiber rods or support rods forming the volume.

[0014] Another advantageous development is one in which a support rod is connected to the connecting rod at their common junction by pressing the support rod to the connecting rod. By pressing the fiber rods together, the impregnated fiber rods bond partially via their external matrix and are thus bonded together. The support rod and the connecting rod are bonded together.

[0015] A further development is advantageous in which the fiber rods have a matrix made of a thermoplastic or a thermosetting plastic, at least at the nodes.

[0016] Another advantageous design variant is one in which one fiber rod is connected to another fiber rod, or a support rod to the connecting rod, at their common node by the matrix. The fiber rods are either impregnated in their intended, truss-like configuration or are arranged to form the truss shortly after impregnation. The matrix of the fiber rods mixes and, as the matrix hardens, forms an inseparable, integral bond between the fiber rods. The matrix can also enclose the entire truss structure and fill cavities within the truss structure.

[0017] In an advantageous embodiment, a fiber rod is connected to another fiber rod, or a support rod to the connecting rod, at their common node by a plastic that at least partially surrounds the fiber rod and the other fiber rod, or the support rod and the connecting rod. The plastic forms at least the node and thus connects the fiber rods to one another. Alternatively, the plastic can also enclose the entire framework structure formed by the fiber rods and fill cavities in the framework structure. The plastic envelops the fiber rods impregnated with the matrix.

[0018] To produce a fiber component described here, for example, the at least three fiber rods can be inserted into a tool such that at least two of the at least three fiber rods are arranged parallel and spaced from one another, and at least one fiber rod is wound around the at least two fiber rods and forms at least one node with them at their connection points. The fiber rods are impregnated with the matrix, and then, after a curing time, the fiber component is separated from the tool. The fiber rods can be impregnated before or after the fiber rods are inserted into the tool. Prepregs (pre-impregnated fiber rods) can also be inserted into or used in the tool. After the fiber rods have been inserted into the tool, the fiber component formed from the at least three fiber rods is separated from the tool after a curing time.

[0019] It is advantageous that the tool has a lost mold or is a lost mold into which the at least three fiber rods are arranged when inserted into the tool. The lost mold is preferably made of wax and can be produced using a 3D printing process.

[0020] By combining the steps of arranging the fiber rods in the lost mold and the step of manufacturing the lost mold, complex structures can be realized. For example, a 3D printer can produce a portion of the lost mold, into which a robot inserts one or more fiber rods. After inserting the fiber rods, another portion of the lost mold can be produced by the 3D printer, which then follows another insertion of fiber rods.

[0021] Another advantage is that the lost mold is meltable and is melted when the fiber rods are separated from the tool. As the lost mold melts, the molten lost mold flows out of the framework formed from at least three fiber rods.

[0022] It is advantageous that the at least three fiber rods are inserted into the lost mold by a robot and arranged relative to one another so that the at least three fiber rods form the truss structure.

[0023] Another advantage is that the tool can alternatively have a blow mold core, a silicone core, or a rubber-elastic core. The blow mold core, the silicone core, or the rubber-elastic core can be removed from the fiber component and thus reused. The blow mold core, the silicone core, or the rubber-elastic core are permanent molds.

[0024] Alternatively, it is advantageous that the tool has a core that remains in the fiber component or can be demolded from the fiber component.

[0025] In a component comprising a plurality of fiber components, it is advantageous that the fiber components of the plurality of fiber components are each straight, a fiber component of the plurality of fiber components is connected on one side in the longitudinal direction to a side in the longitudinal direction of another fiber component of the plurality of fiber components at a connection point, the fiber component is arranged at an angle to the other fiber component, and a flexible element is fixed at a plurality of connection points such that the flexible element forms a radius following the connection points. The flexible element is, for example, a sheet metal and forms the outer surface or visible surface of a structure.

[0026] The features disclosed above can be combined as desired as long as this is technically possible and they do not contradict each other.

[0027] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. They show: Fig. 1 shows a flat fiber component not according to the invention in an isometric view; Fig. 2 shows the flat fiber component from Figure 1 in a side view; Fig. 3 a fiber component forming a space frame in an isometric view; Fig. 4 a fiber component forming a space frame in a side view; Fig. 5 a fiber component forming a space frame in a front view.

[0028] The figures are schematic examples. Like reference numerals in the figures indicate like functional and / or structural features.

[0029] Figure 1 shows, for illustration purposes, a flat fiber component 1 not according to the invention, which is formed from three fiber rods 10. Two of the three fiber rods 10 are arranged parallel to one another as support rods 10' and have a distance between them. The axial direction X of the two parallel support rods 10' does not change. The third fiber rod 10 is wound in a zigzag shape as a connecting rod 10" around the two parallel support rods 10'. At the connection points 12 of the connecting rod 10" with the two parallel support rods 10', the respective fiber rods 10 form node points 11. The connecting rod 10" only changes the orientation of its axial direction X at the node points 11 and runs between the node points 11 without changing the orientation of its axial direction X. The fiber component of the Figure 1 extends essentially in the plane, making it approximately two-dimensional.

[0030] Figure 2 shows the fiber component from Figure 1 in a side view.

[0031] Figure 3 shows another fiber component 1, which is however formed by four parallel support rods 10' and two connecting rods 10". Two of the parallel support rods 10' lie in two spaced-apart planes, whereby a cuboid volume is spanned between the four support rods 10'. A connecting rod 10" is wound around the four support rods 10', so that the fiber component 1 is a support 1'. At the connection points 12 of the connecting rod 10" with the support rods 10', the fiber rods 10 form nodes 11, wherein the connecting rod 10" changes the orientation of its axial direction X at the nodes 11. The fiber rods 10 and the nodes 11 are embedded in a matrix which, after curing, stiffens the fiber rods 10 and the nodes 11.

[0032] Figure 4 shows a side view of the fiber component from Figure 3 .

[0033] Figure 5 shows a front view of the fiber component from Figure 3 .

[0034] The invention is not limited in its implementation to the preferred embodiments described above. Rather, a number of variants are conceivable, which utilize the presented solution even in fundamentally different designs. For example, the truss structure can be used to form fiber components with geometries other than a beam or rod, such as cuboids, spheres, or complex irregular geometries. Fiber composite components produced in this way can be used, for example, as bicycle frames or for other sports equipment.

Claims

1. Fibre component (1) comprising at least three fibre rods (10) each having fibres extending continuously in the axial direction (X) of the fibre rods (10), wherein at least two of the three fibre rods (10) each form a support rod (10'), and at least one of the three fibre rods (10) each forms a connecting rod (10"), the support rods (10') are arranged substantially parallel to and spaced apart from one another in their axial direction (X), the connecting rod (10") connects the support rods (10') to one another, and the connecting rod (10") respectively forms a node point (11) with the respective support rod (10') at the respective connecting points (12) between the connecting rod (10") and the support rods (10'), wherein at least three fibre rods (10) each form a support rod (10'), the support rods (10') are arranged parallel to one another in their axial direction X and on at least two spaced-apart planes, with the result that they form an imaginary volume between them, characterized in that at least one connecting rod (10") is wound around the support rods (10') forming the imaginary volume, and the at least one connecting rod (10") forms the node points (11) with the support rods (10') forming the volume at its connecting points (12) with the support rods (10') forming the imaginary volume.

2. Fibre component (1) according to the preceding claim, wherein the at least three fibre rods (10) form a framework structure through their arrangement with respect to one another.

3. Fibre component (1) according to one of the preceding claims, wherein the at least one connecting rod (10"), together with the support rods (10') forming the imaginary volume, form a three-dimensional framework through their arrangement with respect to one another.

4. Fibre component (1) according to one of the preceding claims, characterized in that the fibre component (1) is a support (1') whose lateral surfaces consist at least in part of the at least three fibre rods (10) which are arranged in the framework structure or in the plurality of framework structures.

5. Fibre component (1) according to the preceding claim, characterized in that the support (1') is determined by the support rods (10'), and the lateral surfaces are each situated between two of the parallel support rods (10').

6. Fibre component (1) according to one of the preceding claims, characterized in that a support rod (10') is connected to the connecting rod (10") at their common node point (11) by press-moulding the support rod (10') with the connecting rod (10").

7. Fibre component (1) according to one of the preceding claims, wherein the fibre rods (10) have, at least at the node points (11), a matrix consisting of a thermoplastic or a thermoset.

8. Fibre component (1) according to the preceding claim, characterized in that a support rod (10') is connected together with the connecting rod (10") at their common node point (11) by the matrix.

9. Fibre component (1) according to one of the preceding claims, characterized in that a support rod (10') is connected together with the connecting rod (10") at their common node point (11) by a plastic which at least partially surrounds the support rod (10') and the connecting rod (10").