Method of manufacturing composite component for articulating with other components

Abstract

The invention relates to a method of manufacturing a fibrous preform for a component, the method comprising:-weaving a first core texture having an elongated shape extending in a longitudinal direction and comprising, in cross section, a central portion (10) having two edges on opposite sides thereof, each edge comprises two scattered fiber portions (16a, 16b); -shaping a first texture involving at least unfolding the scattered portions to form a positioning surface (30) defined by the so-unfolded portions and interlaced portions located between these unfolded portions, which may be formed by an elongated portion (18a) of the central portion; positioning a second belt texture over the spread transverse portion and the interwoven fiber portion, the second texture forming a loop around the shaped first texture to define an empty space for articulation to other components.

Description

Technical Field

[0001] The invention relates to a method for producing a composite component preform for articulation at its ends with other components and to a method for producing such a component. Background Art

[0002] In order to reduce weight, it is possible to propose the use of composite materials instead of metal materials, which is a constant concern in the particular case of aircraft components. In view of this, document US 7 704 429 proposes the manufacture of a landing gear strut made of composite materials, which includes areas called yokes, which are used for articulation and stress introduction with other components and are formed by a laminated structure with a sandwich of layers between the main layers, which makes the body of the reinforcement extended. However, this solution has disadvantages. In fact, compared with metal parts, a yoke with a laminated construction leads to an increase in the size of the stress introduction area to avoid the risk of delamination. Then, the weight reduction of the entire system becomes uninteresting, and the integration of the components becomes more limited due to the increased volume. Another problem is that the proposed manufacturing technology involves a lot of manual intervention, which leads to inconsistencies and increased costs. Finally, the mechanical properties of the composite material proposed in this document can be improved, especially in terms of compressive strength on the middle area of ​​the length of the component, which is called the common area. One option to solve this problem is to add material in this common area, which is then unfavorable to quality and therefore cannot provide complete satisfaction.

[0003] The present invention is intended to address all or part of the above-mentioned disadvantages. Summary of the invention

[0004] The invention relates to a method for producing a fiber preform for a composite component to be hinged to other components, the method comprising at least: - forming a first fiber core texture by weaving, the first fiber core texture having an elongated shape extending in the longitudinal direction and comprising in cross section a central portion having two positioning edges on opposite sides thereof, each positioning edge comprising two non-interconnected transverse fiber portions; - forming a first fiber texture, which involves at least spreading the non-interconnected transverse portions to form a positioning surface defined by the transverse portions so spread and by a portion of interwoven fibers located between these spread portions, formed by the extension of said central portion or by this central portion; and - Positioning a second braided tape fiber texture over the expanded transverse portion and the interwoven fiber portion, the second texture forming a loop around the formed first texture so as to define a void space at the longitudinal ends between the first and second textures for articulation to other components.

[0005] The invention proposes a solution based on an assembly between a core and a belt, each resulting from a weaving operation, having a belt positioning surface formed by an interlaced portion and an unfolded non-interconnected portion situated on either side thereof. This solution provides an excellent interface for the assembly, thus guaranteeing a good retention of the composite component and, in particular, allowing an improvement in the mechanical properties, in particular in terms of compressive strength, without compromising the quality of the structure, compared to US 7 704 429. In particular, it is advantageous that the positioning surface, having a substantially planar shape due to the presence of the interlaced portion, avoids the use of third-party filling materials between the unfolded portions. The non-interconnected portions allow, after forming, an increase in the rigidity along all the stress axes of the component (optimization of inertia). The belt technology according to the invention also allows a greater economy in terms of manufacturing costs than the prior art solutions discussed.

[0006] According to one example, each positioning edge further comprises an interwoven fiber texture extending the central portion and located between the non-interconnected transverse fiber portions, and the forming further comprises cutting the interwoven fiber texture to form the interwoven fiber portions.

[0007] According to this example, the interwoven portion is formed by a remaining fabric extension of the central portion within the positioning edge, which remaining fabric extension results from the cutting of the interwoven fiber texture.

[0008] According to one variant, the central portion comprises woven surface layers and non-woven yarn groups, which are located between the woven surface layers and held together by yarns from the woven surface layers, these woven surface layers extending beyond the central portion into the positioning edges to form non-interconnected transverse fiber portions, and wherein, during forming, these non-interconnected portions are unfolded so as to fold them down to the height of the non-woven yarn groups.

[0009] According to this variant, the interlaced portion is formed by the central portion itself, is located at the same level as the non-interconnected portion that is developed, and allows to avoid having to perform the above-mentioned cutting operation. In addition, the non-woven yarn group forms a stiffening portion that allows to further improve the compressive strength compared to a structure obtained entirely by three-dimensional weaving.

[0010] In an exemplary embodiment, the non-interconnected transverse fiber portion is formed by weaving a first yarn and a second yarn, and has a first volume ratio of the first yarn relative to the second yarn; and the second texture is formed by weaving the first yarn and the second yarn, and has a second volume ratio of the first yarn relative to the second yarn, and the relative difference between the first volume ratio and the second volume ratio does not exceed 25%, for example, does not exceed 10%.

[0011] This feature helps to further increase the mechanical strength of the composite part to be obtained.

[0012] In one exemplary embodiment, the first texture and the second texture are made of carbon yarns.

[0013] The invention also relates to a method for manufacturing a composite material component for articulation with other components, the method comprising at least: - forming a fiber preform for the component to be obtained by implementing the method as described above; and - A matrix is ​​formed in the pores of the fiber preform thus obtained.

[0014] In one exemplary embodiment, the matrix is ​​organic.

[0015] In an exemplary embodiment, the component is a landing gear strut, a section of a landing gear strut or a brake rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [ Figure 1 ] Figure 1 One example of a first fiber core texture that can be used in the context of the present invention is schematically shown.

[0017] [ Figure 2 ] Figure 2 Schematically shows the Figure 1 Cross section of the first texture.

[0018] [ Figure 3A ] Figure 3A A first step of an example of forming a first texture according to the present invention is shown.

[0019] [ Figure 3B ] Figure 3B A second step of an example of forming a first texture according to the present invention is shown.

[0020] [ Figure 3C ] Figure 3C A third step of an example of forming a first texture according to the present invention is shown.

[0021] [ Figure 3D ] Figure 3D A fourth step of an example of forming a first texture according to the present invention is shown.

[0022] [ Figure 4 ] Figure 4 An example of a composite part preform obtained after positioning a second ribbon-like texture on a shaped first texture is schematically shown.

[0023] [ Figure 5 ] Figure 5A cross section of a variant of a first texture that can be used in the context of the present invention is schematically shown.

[0024] [ Fig. 6A ] Fig. 6A Shows Figure 5 A possible first step in the shaping of the texture.

[0025] [ Figure 6B ] Figure 6B The second step of the forming is shown.

[0026] [ Figure 6C ] Figure 6C The third step of the forming is shown, comprising the positioning of the tape on the formed texture. DETAILED DESCRIPTION

[0027] Figure 1 An example of a first fiber texture 1 that can be used in the context of the present invention is illustrated. The first texture 1 has an elongated shape extending in a longitudinal direction X. As will be described below, it can be obtained in one piece by three-dimensional weaving by providing non-interconnected areas. "Three-dimensional weaving" or "3D weaving" refers to a weaving method by which at least some of the first yarns oriented in the X direction bind the second transverse yarns to the first yarns on several layers of second yarns. This weaving can be performed in a jacquard-type loom in a manner known per se. The first texture 1 is used to form the core of the fiber reinforcement of the component to be obtained. For example, a "double rib" weaving pattern can be used to form the first texture 1. The first texture 1 has a longitudinal end 3, which has a curved shape (e.g., approximately circular) and is used to define an empty space dedicated to articulation with other components in the component to be obtained. In the example shown, the longitudinal ends 3 have substantially the same size, but those skilled in the art will recognize that other variations are also possible, and in particular, the present invention can be applied to components with longitudinal ends of different sizes.

[0028] The first texture 1 may be in the form of strips, and Figure 2A cross section thereof is shown which is taken transversely to the longitudinal direction X. The first texture 1 comprises a central portion 10 having two edges 12 on opposite sides 11 of the central portion, which are used to position the second texture and are referred to as positioning edges 12. The central portion 10 and the edges 12 each extend in the longitudinal direction X. The central portion 10 is located between the edges 12. In the example shown, the edges 12 and the central portion 10 are offset along the width (direction L) of the first texture. In the example shown, each positioning edge 12 has, in sequence, a first non-interconnected transverse fiber portion 16a, an interwoven fiber texture 18 and a second non-interconnected transverse fiber portion 16b along the thickness (direction E) of the first texture 1 (corresponding to its smallest dimension). There is a first non-interconnected region 14a between the first portion 16a and the texture 18, and a second non-interconnected region 14b between the texture 18 and the second portion 16b. In the non-interconnected regions 14a, 14b, the yarn layers of the woven texture 18 and the yarn layers of the parts 16a, 16b between them are intentionally omitted so that the parts 16a, 16b can be unfolded, which will be described below. The non-interconnected regions 14a, 14b start from the side 11. Each of the parts 16a, 16b extends the central part 10 beyond the side 11. In the example shown, the parts 16a, 16b and the interwoven texture 18 are obtained by three-dimensional weaving like the central part 10, but when this is not the case, it does not depart from the scope of the present invention. In particular, the interwoven texture can be formed by non-woven yarn layers (unidirectional yarn layers). It should be noted that the non-interconnected regions 14a, 14b can extend over the entire length or part of the length of the first texture 1, in particular, over at least 50% of the length LD of the first texture 1. In particular, the non-interconnected regions 14a, 14b can be present in the middle region ZM of the length of the first texture 1. The example considered relates to the case where the height of the non-interconnected zones 14a, 14b measured along the direction L does not vary along the longitudinal direction X, but in this case it does not depart from the scope of the invention, especially in the specific case where the longitudinal ends 3 have different dimensions. In particular, the height of the non-interconnected zones 14a, 14b may vary so as to reach a maximum in the intermediate zone ZM, thereby further improving the quality of the interface with the belt and thus improving the mechanical properties of the common zone, in particular the inertia of the core, thereby increasing the buckling resistance under compressive loads or vibration modes. A possible structure of the first texture 1 has just been described, and below in combination FIG. 3A to FIG. 3D The focus is on describing in detail its possible shaping in order to prepare for the positioning of the second belt texture.

[0029] like Figure 3AAs shown, the first texture 1 is positioned in a first tool 20, which includes two segments 22 for supporting on the first texture 1. More specifically, the central portion 10 is held between the segments 22, and the segments 22 can optionally apply compaction pressure to the central portion 10 if the fiber rate needs to be adjusted. As shown in the figure, the two segments 22 can be offset along the direction E. The segment 22 has a face 22a and a curved surface 22b, and the face 22a can be substantially planar and supported on the central portion 10; the curved surface 22b extends from the face 22a in a direction opposite to the first texture 1. The face 22b defines an area 24, particularly near the positioning edge 12, and the non-interconnected portions 16a, 16b are used to cover the area 24 during cutting of the interwoven texture 18. Therefore, as shown in Figure 3B As shown, the non-interconnected portions 16a, 16b are spaced apart from one another so as to be positioned on the region 24 of the respective segment 22, thereby releasing them from the interwoven texture 18. The non-interconnected portions 16a, 16b folded on the region 24 are retained in this region 24 by means known per se, for example by compression. Figure 3C As shown, the interwoven texture 18 is cut along the cutting line LD. The cutting can be performed by water jet cutting, but those skilled in the art will recognize that other techniques are also possible. As shown, the cutting of the interwoven texture 18 can be performed flush with the non-interconnected parts 16a, 16b held on the segment 22. In addition, the curved shape of the face 22b ensures that the non-interconnected parts 16a, 16b extend away from the cutting line LD, thereby avoiding any risk of damage during this operation. The cutting residue of the texture 18 forms an interwoven portion 18a, which is located between the non-interconnected parts 16a, 16b and will be used as a supporting surface for the belt texture. Part 18a is located in the fabric extension of the central part 10. The fabric portion 18a can have a sufficiently short length to have sufficient rigidity, thereby allowing it to maintain a straight shape along the direction L without any holding tool.

[0030] Once this cut has been made, the first texture is removed from tool 20 and positioned between two shaped bodies 23 of a second, different tool 21, which is the tool used to shape the core of the part to be obtained. Figure 3DSuch a forming is shown in which the non-interconnected portions 16a and 16b are spread out on the forming body 23 to form transverse fins and the first texture 13 so formed has an I-shaped cross section (known as a double angle shape). In the example shown, each spread out non-interconnected portion 16a, 16b forms an elbow with the central portion 10, the angle of which is substantially equal to 90° with the direction L. The formed first texture 13 defines, on either side of the central portion 10, at the positioning edge 12, a positioning surface 30 on which the second belt texture will be deposited. The positioning surface 30 is defined by the spread out non-interconnected portions 16a, 16b and by the interlaced portion 18a extending the central portion 10, the interlaced portion 18a allowing the lack of material caused by the spread out non-interconnected portions 16a, 16b to be filled. This provides a good interface with the belt and in particular a positioning surface 30 of substantially planar shape, as shown in FIG. Figure 3D The example just described uses two different tools, one for cutting and the other for forming the first texture, but it would not depart from the scope of the invention if the same tool were used for both operations. Figure 4 As shown, the method continues by positioning the second woven tape fiber texture 40 around the first texture 13 formed by the tool 21. The second texture 40 can have the shape of a strip wrapped around the formed first texture 13. When the second texture 40 is positioned, the second texture 40 is supported on the unfolded parts 16a, 16b, but also on the interlaced part 18a, which allows a good interface to be provided between the two textures. The second texture 40 can be in the form of a single fabric strip, but it does not depart from the scope of the invention if the second texture is in the form of several strips placed end to end or side by side. The second texture 40 can also be obtained by three-dimensional weaving, for example with a "double rib" pattern. The second texture 40 defines a closed loop around the formed first texture 13 and defines an empty space 42 for articulation to other components. Inserts (not shown) can be temporarily used at the longitudinal ends 3, and the second texture 40 can be wrapped around these inserts to ensure the desired shape of the end area. As mentioned above, the volume ratios between the warp and weft yarns of each of the first texture 11 and the second texture 40 may be similar. These volume ratios correspond to the ratio: [volume occupied by warp yarns] / [volume occupied by weft yarns] for each considered texture.

[0031] Then, the matching mold is positioned around the assembly of the two textures 13 and 40 so that the cavity for introducing the matrix material is defined with the tool 21, and then the assembly is densified, for example, by introducing a resin (such as an epoxy resin), which is then cross-linked if the resin is a thermosetting resin, or is then cooled if the resin is a thermoplastic resin. The formation of the matrix can be carried out by a resin transfer molding technique corresponding to the known technology itself. In this way, a composite material component is obtained, which is used to be hinged with other components at its longitudinal ends. The fiber reinforcement of the component can be formed by carbon yarns, and the component can have an organic matrix as just described. The component can be used for aviation applications or not. The component can be, for example, a connecting rod, a landing gear strut or its component element, or a brake rod. The component can be used to mainly withstand tensile and compressive forces in operation. The obtained component can be installed on other components by positioning a hinge pin for connecting to other components and a contact insert with the pin through the empty space 42.

[0032] The example just described relates to the case where the interlaced portion 18a is formed by a fabric extension of the central portion 10. However, the invention also contemplates the case where the central portion itself is located between the unfolded non-interconnected portions to provide a load-bearing surface for the second belt texture. Figure 5 and FIG. 6A to FIG. 6C Let's discuss this example.

[0033] Figure 51 is a cross-sectional view of a variation of a first texture 100, which includes a central portion 110 over its entire length or a portion of its length. The central portion 110 has two positioning edges 120 on opposite sides 111. Each positioning edge 120 includes non-interconnected lateral portions 160a, 160b separated by non-interconnected areas 140, thereby allowing these portions 160a, 160b to be spaced relative to each other. As in the previous example, the positioning edges 120 and the central portion 110 are offset along the width direction L, and the non-interconnected portions 160a, 160b are offset along the thickness direction E. The first texture 100 includes a woven surface layer 102a, 102b, for example obtained by three-dimensional weaving, which forms a section of the central portion 110 and extends along the extension of this portion so as to form non-interconnected portions 160a, 160b. The surface layers 102a, 102b are formed by weaving between first yarns C1 to C4 and C13 to C16 extending along the longitudinal direction X and second yarns t1 to t8 extending along the direction L. In general, it will be appreciated that the number of yarn layers shown and the weaving pattern are provided as examples only and may be modified without departing from the scope of the invention. The central portion 110 also includes a group 102c of non-woven yarns C5 to C12 located between the surface layers 102a, 102b and held together by yarns from the surface layers 102a, 102b. In fact, it is noted that the yarn t4 extends in the first surface layer 102a outside the central portion 110 and is deflected so as to be exposed from the first surface layer 102a to combine the group 102c of yarns C5 to C12 in the central portion 110. Similarly, the yarn t5 extends in the second skin 102b outside the central part 110 and is deflected so as to be exposed from the second skin 102b to combine the group 102c of yarns C5 to C12 in the central part 110 on the side opposite to the yarn t4. An encapsulation of the group 102c of non-woven yarns C5 to C12 is obtained between the skins 102a, 102b, which are held in place by the deflected yarns t4 to t5. In the example shown, there are sequentially in the central part 110 along the thickness direction E: the first skin 102a, the non-woven yarn group 102c and the second skin 102b. It should be noted that the non-woven yarn group 102c is only present in the central part 110, and not in the positioning edge 120. It should also be noted that the yarns C5 to C12 may be non-woven only over a length of the first texture 100, for example, in the middle zone ZM thereof, but may be woven at the longitudinal ends of the first texture 100. The length over which the yarns C5 to C12 are non-woven may be greater than or equal to 50% of the length of the first texture 100. FIG. 6A to FIG. 6C The diagram is simplified Figure 5With regard to the forming of the first texture and the positioning of the second tape texture 40, it will be understood that the construction is symmetrical with respect to the directions L and E. In the example considered, there are openings of the non-interconnected portions 160a, 160b on the forming body (not shown) so as to form an angle of substantially 90° with the direction L and to position the non-interconnected portions 160a, 160b at the height of the non-woven yarn group 102c. This height is taken along the direction L. This gives a positioning surface 130 of generally planar shape, in which the non-interconnected portions 160a, 160b and the yarn group 102c of the central portion 110 located between these non-interconnected portions are at the same level and therefore define a support surface for the tape texture 40.

Claims

1. A method for producing a fiber preform for a composite component to be hinged to another component, the method comprising at least: - forming a first fiber core texture by weaving (1; 100), said first fiber core texture having an elongated shape extending in a longitudinal direction (X) and comprising in cross section a central portion (10; 110) having two positioning edges (12; 120) on opposite sides (11; 111), each positioning edge comprising two non-interconnected transverse fiber portions (16a; 16b; 160a; 160b), - forming said first fiber texture, said forming said first fiber texture involving at least spreading said non-interconnected transverse portions to form a positioning surface (30; 130) defined by the transverse portions so spread and by an interwoven fiber portion located between said spread portions, formed by a prolongation (18a) of said central portion or by said central portion (110), and - Positioning a second braided tape fiber texture (40) over the unfolded transverse portion and the interwoven fiber portion, the second texture forming a loop around the formed first texture so as to define a void space (42) at the longitudinal ends between the first and second textures for articulation to other components.

2. The method according to claim 1, wherein: Each positioning edge (12) further comprises an interwoven fiber texture (18) extending the central portion (10) and located between the non-interconnected transverse fiber portions (16a; 16b), and wherein the forming further comprises cutting the interwoven fiber texture to form the interwoven fiber portions (18a).

3. The method according to claim 1, wherein: The central portion (110) comprises woven surface layers (102a; 102b) and a non-woven yarn group (102c), the non-woven yarn group being located between the woven surface layers and held together by yarns (t4; t5) from the woven surface layers, the woven surface layers extending beyond the central portion into the positioning edge (120) to form the non-interconnected transverse fiber portions (160a; 160b), and wherein these non-interconnected portions are unfolded so that they are folded down to the height of the non-woven yarn group during forming.

4. The method according to any one of claims 1 to 3, wherein: The non-interconnected transverse fiber portion (16a; 16b; 160a; 160b) is formed by weaving a first yarn and a second yarn, and has a first volume ratio of the first yarn to the second yarn; and wherein the second texture (40) is formed by weaving a first yarn and a second yarn, and has a second volume ratio of the first yarn to the second yarn, and the relative difference between the first volume ratio and the second volume ratio does not exceed 25%.

5. The method according to any one of claims 1 to 4, wherein: The first texture (1; 100) and the second texture (40) are made of carbon yarn.

6. A method of manufacturing a composite component for articulation with other components, the method comprising at least: - forming a fiber preform for the component to be obtained by implementing a method according to any one of claims 1 to 5; as well as - A matrix is ​​formed in the pores of the fiber preform thus obtained.

7. The method according to claim 6, wherein: The matrix is ​​organic.

8. The method according to claim 6 or 7, wherein: The component is a landing gear strut, a section of a landing gear strut or a brake rod.

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