Method for producing a preform for a blade or propeller component by winding a braid obtained by braiding

Abstract

The invention relates to a method for producing a fiber preform for a component of a blade or propeller for a turbine, the fiber preform comprising at least one attachment root for mounting a partial extension of an airfoil, the method comprising at least winding a fiber braid (12) obtained by braiding onto a substrate with a variable cross-section, the substrate having at least a first region with extra thickness in the shape of the attachment root and a second region in the shape of a portion for mounting the airfoil.

Description

Technical Field

[0001] The invention relates to the manufacture of preforms for blade or propeller components with varying thickness, wherein contour weaving is used to form a fiber texture to be wound on a substrate having the shape to be obtained. The invention also relates to a method for manufacturing the related components made of composite materials. Background Art

[0002] A turbopropeller part having a fixed base with an additional thickness, called a "bulb-shaped base" or "tulip-shaped base", extended by a spar, on which the aerodynamic profile is intended to be assembled, can be obtained by superimposing layers of fiber braids around a foam mandrel. In this way, deviations from the expected fiber orientation can be observed, in particular in the areas where the diameter of the workpiece varies, which deviations may affect the mechanical properties. It may further be sought to increase the amount of fibers along the longitudinal axis of the propeller to be obtained. Since the braiding machine can only store a limited number of axial fibers, it may be necessary to manually cover additional layers of unidirectional fibers during braiding, which would lengthen and complicate the method. In addition to this, an intermediate pre-compacting operation may be added to limit the expansion of the preform thus constructed, which is then placed in a mold for resin injection by resin transfer molding technology. US2011 / 0038732 discloses a turbine blade made of composite material.

[0003] It is therefore desirable to have a method for manufacturing propeller components and blade components for turboprop engines which makes it possible to overcome the disadvantages associated with the on-mandrel braiding technique. Summary of the invention

[0004] The invention proposes a method for manufacturing a fiber preform for a blade or propeller component of a turbomachine, the fiber preform comprising at least one fixing base extending with a mounting portion of an aerodynamic profile, the method comprising at least:

[0005] - Winding the fiber texture obtained by contour weaving on a substrate with variable cross-section, the substrate having at least a first zone with extra thickness in the shape of a fixed base, and a second zone in the shape of a mounting portion with an aerodynamic profile.

[0006] The invention proposes to manufacture, by means of a contour weaving technique, a texture of a preform intended to be wound to form a blade or propeller component, a technique known per se for obtaining other types of workpieces, implementing a take-up mandrel with a non-cylindrical shape at the outlet of the loom to take up the texture with partial lengths of circumferential yarns (corresponding to the warp yarns) onto the take-up mandrel, which is suitable for allowing the texture to adapt to the shape of the substrate during winding without deformation.

[0007] The invention thus makes it possible to overcome the drawbacks associated with braiding techniques, to produce workpiece parts of complex shape and to obtain the desired fiber orientation even in areas of thickness variation. The invention also allows high productivity and has manageable implementation costs, without requiring complex machining, but only requiring possible finishing after the formation of the matrix.

[0008] In an exemplary embodiment, a fiber texture is wound on a substrate together with a multiaxial web having a fiber orientation different from that of the fiber texture. In this case, the multiaxial web may be present on all or part of the winding of the fiber texture, as described below.

[0009] Such a characteristic advantageously makes it possible to increase the shear resistance of the workpiece obtained.

[0010] In particular, the multiaxial web comprises at least one first unidirectional fiber layer oriented at +45° relative to the longitudinal axis of the substrate and superposed by at least one second unidirectional fiber layer oriented at -45° relative to the longitudinal axis of the substrate.

[0011] In one exemplary embodiment, the fixing base of the fiber preform is axisymmetric.

[0012] In an exemplary embodiment, the texture is obtained by contour weaving using a take-up mandrel at the outlet of the loom, the take-up mandrel being separated from the substrate and having at least a first yarn take-up area with a first radius and a second yarn take-up area with a second radius, the first radius being greater than the second radius, the yarn taken up in the first area being wound on the first area of ​​the substrate, and the yarn taken up in the second area being wound on the second area of ​​the substrate.

[0013] Such a characteristic advantageously makes it possible to increase the proportion of warp threads in the circumferential direction on the fixed base, which increases the resistance of the workpiece to the loads encountered in operation. However, as a variant, if the proportion of weft threads is increased, it does not deviate from the framework of the invention. In general, the warp / weft ratio is determined according to the load-dependent area of ​​the workpiece.

[0014] In one exemplary embodiment, the weaving of the shape of the texture and the winding of the texture on the substrate are performed continuously.

[0015] Such characteristics advantageously enable further improvement in productivity.

[0016] In one exemplary embodiment, the substrate is obtained by three-dimensional weaving.

[0017] In this case, the substrate forms a structural component intended to remain in a propeller or blade installed in a turbomachine in order to improve its mechanical properties.

[0018] The invention also relates to a method for manufacturing a composite blade or propeller component for a turbomachine, comprising at least:

[0019] - manufacturing a fiber preform for a blade or propeller component of a turbomachine by implementing the method as described above; and

[0020] - Formation of a matrix in the pores of the fiber preform thus obtained.

[0021] The invention also relates to a method for manufacturing a composite blade or propeller for a turbomachine, comprising at least:

[0022] - forming a fiber preform as described above for a blade or propeller component for a turbomachine;

[0023] - positioning the aerodynamically profiled fiber preform on the mounting part; and

[0024] - Jointly densifying the fiber preform of the turbine blade or propeller component and the fiber preform of the aerodynamic profile positioned on the preform to obtain the turbine blade or propeller.

[0025] In an exemplary embodiment, a fan blade is obtained, for example a variable pitch fan blade, but the invention is not limited to this example which will be described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [ Figure 1 ] Figure 1 An example of a prefabricated part of a blade or propeller component of a turbomachine which can be obtained by implementing the invention is shown schematically and in perspective.

[0027] [ Figure 2 ] Figure 2 Schematically shows Figure 1 Longitudinal section of a preform equipped with an aerodynamic profile.

[0028] [ Figure 3 ] Figure 3 Schematic diagram of the formation of fiber texture by contour weaving to form Figure 1 of prefabricated parts.

[0029] [ Figure 4 ] Figure 4 Shows Figure 3 Longitudinal section of the take-up mandrel used in.

[0030] [ Figure 5 ] Figure 5 Schematically shows the Figure 3 The fiber texture formed by contour weaving is wound together with the multiaxial web.

[0031] [ Figure 6 ] Figure 6 Details of a multiaxial web are shown. DETAILED DESCRIPTION

[0032] Figure 1 An example of a fiber preform 1 according to the invention is shown, which is intended to form a fiber reinforcement of a component of a variable pitch fan blade made of composite material. Such a workpiece can be adjusted into position about its axis to optimize the air flow in the fan. The remainder of the present specification attempts to describe the application of the invention to this type of workpiece, but a person skilled in the art will recognize that the invention can also be applied to other types of workpieces, such as general ducted rotary blades or propellers. The blade or propeller may or may not be a variable pitch blade or propeller. The blade or propeller may or may not be a workpiece of an aviation turbine, so the invention can be applied to the manufacture of wind turbine propellers.

[0033] The fiber preform 1 comprises a fixing base 3 defining an extra thickness, also called a "bulb-shaped base" or "tulip-shaped base", through which the majority of the forces in operation pass, which is extended by a mounting portion 5 of an aerodynamic profile, here in the shape of a flattened portion forming a spar. Once densified, the fixing base 3 is intended to be mounted on the turbine rotor by engagement in a housing arranged on the periphery of the rotor of corresponding shape. A preform 7 of an aerodynamic profile (airfoil part) is intended to be assembled onto the mounting portion 5 (see Figure 2 ), so as to obtain a complete piece, if desired, by interposing a third element, such as foam (not shown). A transition portion 4 is present between the fixing base 3 and the mounting portion 5. The thickness of the transition portion 4 decreases in the direction of the mounting portion 5. The fiber preform 1 also comprises a pivoting element 9, which defines the end of the preform 1 and is located on the side opposite to the mounting portion 5, and which enables the blade to be pivoted relative to its axis in operation in order to optimize its orientation.

[0034] The preform 1 is obtained by winding a fiber texture on a substrate of non-expandable shape having the shape of the preform to be obtained, in particular with a variable section between a first zone with additional thickness intended to define a fixing base 3 and a second zone intended to define a mounting portion 5. According to the invention, the fiber texture is obtained by a contour weaving technique so that the texture adapts to the shape of the substrate during winding without deforming it.

[0035] The shape of the texture is woven like Figure 3 and Figure 4As shown. According to this technology, a take-up mandrel 14 with a non-cylindrical geometry located directly at the outlet of the loom 10 is used to take up the warp yarns. The take-up mandrel 14 is rotatable (rotation arrow R14 around the axis X14 of the mandrel) and takes up the warp yarns along the take-up direction A by its rotation. The warp yarns are woven together with the weft yarns in the loom 10 to obtain a fiber texture 12. The fiber texture 12 produced by the loom 10 conforms to the take-up mandrel 14 with a specific shape, allowing the texture 12 to be wound on the substrate without deformation. The take-up mandrel 14 has a first cylindrical portion 15 defining a first yarn take-up zone, a second tapered transition portion 17 and a third cylindrical portion 19 defining a second yarn take-up zone along its axis X14. The yarn taken up on the first zone 15 will be wound on a first area of ​​the substrate intended to form a fixed base 3, while the yarn taken up on the second zone 19 will be wound on a second area of ​​the substrate intended to form a mounting portion 5. The geometry of the winding mandrel 14 does not allow the warp yarn to be consumed uniformly along its axis X14. In fact, the length of the warp yarn taken up by the mandrel 14 varies according to the local radius of the mandrel. The higher the local radius of the mandrel 14, the greater the length of the warp yarn taken up during a rotation of the mandrel. Figure 4 As shown, the first winding zone 15 and the second winding zone 19 have different radii R1 and R2, respectively. The contour weaving technique is characterized in that the ratio of the radius R1 / R2 is substantially equal to the ratio of the circumference P1 / P2 on the substrate, where P1 represents the circumference of the first zone of the substrate and P2 represents the circumference of the second zone of the substrate. This makes it possible to ensure that the length of the warp yarns locally wound by the mandrel 14 corresponds to the circumference of the zone of the substrate where these yarns will be wound, so that the texture 12 will not be deformed during winding. In the example shown, the radius R1 is greater than the radius R2, but if the reverse construction is implemented according to the desired geometry of the final workpiece, it does not deviate from the framework of the invention. The first area of ​​the substrate can advantageously be symmetrical about the axis of the substrate so as to form an axisymmetric fixed base 3. In the case where the first area of ​​the substrate is not axisymmetric, for example it has the shape of a polygon with rounded corners, other variations are also possible. Of course, the invention also relates to other geometries with more zones of different radii. The second tapered portion 17 has a profile that enables the formation of a transition portion 4 between the fixed base 3 and the mounting portion 5. It should be noted that the fiber texture 12 can be obtained by three-dimensional weaving or as a variant of two-dimensional weaving. The fiber texture 12 can be formed by carbon, glass or polymer yarns or a mixture of these fibers. It should be noted that the nature of the yarns, the size of the yarns and the weaving can also be locally varied to optimize the mechanical properties of the workpiece. In the obtained preform 1, the warp yarns are oriented circumferentially and the weft yarns are oriented axially.

[0036] Figure 5 The co-winding of the fiber texture 12 obtained by contour weaving on the substrate 20 is shown. Figure 5In the example of , the fiber texture 12 is continuously conveyed from the take-up mandrel 14 on the substrate 20, so that the fiber texture 12 is separated from the take-up mandrel. The substrate 20 is rotated about its axis (arrow R20) so as to take up the fiber texture 12 from the take-up mandrel 14. The rotation of the substrate 20 also makes it possible to remove the multiaxial web 22 from the rotatable mandrel 24 (arrow R24) separated from the take-up mandrel 14, so as to wind the fiber texture 12 and the multiaxial web 22 together on the substrate 20. The number of layers and the number of winding turns of the yarn in the texture 12 are determined according to the desired thickness of the workpiece, which varies according to the load to which the workpiece is subjected during operation. The texture obtained by three-dimensional weaving makes it possible to increase the thickness of the composite material, but several turns are required to obtain the desired workpiece. The use of the texture obtained by two-dimensional weaving is advantageous for composite materials with reduced thickness. In Figure 5 In the case of co-winding shown, an alternation of wound layers of fiber texture 12 and multiaxial web 22 will be obtained in the fiber preform. The co-winding can be carried out on a first zone and on a second zone of the substrate 20. Figure 6 Detail of a multiaxial web 22 is shown, which can be implemented to include a first unidirectional fiber layer, the first unidirectional fiber layer including fibers 22a, which are superimposed on a second unidirectional fiber layer including fibers 22b. The fibers 22a and 22b each have a different orientation, and their orientation is different relative to the orientation of the warp and weft yarns of the fiber texture 12. The fibers 22a and 22b can be oriented at +45° and -45° relative to the longitudinal axis X20 of the substrate 20. The orientation of the fibers 22a and 22b depends on the application envisaged. It will also be noted that the present invention is not limited to co-winding with a multiaxial web 22, and that only the texture 12 can be wound on the substrate 20 in order to obtain a fiber preform 1. It will also be noted that other textures besides the multiaxial web 22 can also be co-wound with the texture 12, such as a two-dimensional fabric, a three-dimensional fabric or a braid. Likewise, in the case where the texture 12 is co-wound with a separate texture, the texture can be present only on a portion of the winding of the fiber texture. The location of the local co-winding is determined by the loads to which the workpiece is subjected. This situation may result from the use of a texture whose width is smaller than the width of the fiber texture. Unless otherwise stated, the width is measured transversely to the winding direction towards the substrate. As a variant, the texture is present over the entire winding of the fiber texture (co-winding over the entire area of ​​the winding texture). Figure 5 and Figure 6 It is illustrated how the texture 12 is formed continuously by contour weaving on a take-up mandrel 14 and by winding on a substrate 20. According to a variant that is not shown, the texture 12 can first be formed by contour weaving and then stored on a storage mandrel in order to subsequently start winding on the substrate 20 after the contour weaving is completed. In the latter case, winding is performed to transfer the contour texture from the storage mandrel to the substrate (as described above, co-winding is possible).

[0037] The substrate 20 on which the texture 12 is wound can have various properties. According to one example, the substrate is intended to remain in the workpiece intended to be installed in a turbine. In this case, the substrate 20 can be structural, for example formed by three-dimensional weaving. According to a variant, it is possible to use a substrate 20 whose density is less than the density of the workpiece made of the composite material to be obtained, for example a substrate 20 made of a cellular material such as foam. According to a variant, it is intended not to remain in the workpiece intended to be installed in a turbine. Thus, it is possible to use a substrate that is to be disassembled or eliminated after winding and possibly after densification of the fiber preform 1. Thus, it is possible to obtain a workpiece with hollow parts at the level of the base of the profile and the mounting part, making it light when desired.

[0038] After winding on the substrate 20, the Figure 1 The fiber preform 1 shown comprises a fixing base 3 and a mounting portion 5. Continuing with the method for manufacturing the workpiece, the fiber preform 7 with an aerodynamic profile is formed as Figure 2 As shown, the preforms 1 and 7 thus assembled are assembled on the mounting portion 5, and then the preforms 1 and 7 thus assembled are subjected to co-densification. The co-densification technique is a method known per se, in which a common matrix is ​​formed in the pores of the preforms 1 and 7 to fix it and obtain a blade or propeller made of a composite material. Co-densification can be carried out by introducing a resin into the pores of the preforms 1 and 7 and heat-treating the resin to cross-link the resin. The resin can be introduced by injection or infusion technology. The resin can be an epoxy resin, a polyamide resin or a polyester resin, but is not limited thereto. The manufactured blade or propeller can be made of an organic matrix composite material. The present invention can also be applied to the formation of a ceramic matrix composite workpiece, for example by introducing a ceramic precursor and then pyrolyzing the ceramic precursor to form a ceramic matrix. After the matrix is ​​formed, the blade or propeller can be installed in the turbine, and if necessary, it may be installed after a step of removing or eliminating, for example, removing or eliminating the substrate 20 by heat treatment or dissolution.

Claims

1. A method for manufacturing a fiber preform for a blade or propeller component of a turbomachine, the fiber preform comprising at least one fixing base extending with a mounting portion of an aerodynamic profile, the method comprising at least: - Winding the fiber texture obtained by contour weaving on a substrate with variable cross-section, said substrate having at least a first zone with extra thickness in the shape of a fixed base, and a second zone in the shape of a mounting portion with an aerodynamic profile.

2. The method according to claim 1, characterized in that: The fiber texture is co-wound on the substrate with a multiaxial web having fibers oriented differently than the fibers of the fiber texture.

3. The method according to claim 2, characterized in that The multiaxial web comprises at least one first unidirectional fiber layer oriented at +45° relative to the longitudinal axis of the substrate and superposed by at least one second unidirectional fiber layer oriented at -45° relative to the longitudinal axis of the substrate.

4. The method according to any one of claims 1 to 3, characterized in that The fixing base of the fiber preform is axisymmetric.

5. The method according to any one of claims 1 to 3, characterized in that The texture is obtained by contour weaving using a take-up mandrel at the outlet of the loom, wherein the take-up mandrel is separated from the substrate and has at least a first yarn take-up area with a first radius and a second yarn take-up area with a second radius, wherein the first radius is greater than the second radius, and the yarn taken up in the first area is wound on the first area of ​​the substrate, and the yarn taken up in the second area is wound on the second area of ​​the substrate.

6. The method according to any one of claims 1 to 3, characterized in that The weaving of the shape of the texture and the winding of the texture on the substrate are performed continuously.

7. The method according to any one of claims 1 to 3, characterized in that The substrate is obtained by three-dimensional weaving.

8. A method for manufacturing a composite blade or propeller component for a turbomachine, comprising at least: - Manufacturing a fiber preform for a blade or propeller component of a turbomachine by implementing the method according to any one of claims 1 to 7; as well as - Formation of a matrix in the pores of the fiber preform thus obtained.

9. A method for manufacturing a composite blade or propeller for a turbomachine, comprising at least: - forming a fiber preform for a blade or propeller component of a turbomachine by implementing the method according to any one of claims 1 to 7; - positioning the aerodynamically profiled fiber preform on the mounting portion; as well as - Jointly densifying a fiber preform of a turbine blade or propeller component and a fiber preform of an aerodynamic profile positioned on the fiber preform of the turbine blade or propeller component to obtain a turbine blade or propeller.

10. The method according to claim 9, characterized in that Get the fan blades.

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