vanes or guide vanes with roots made by crossing of weft threads

Abstract

The invention relates to a method for manufacturing a propeller blade or a vane made of composite material, the method comprising: - manufacturing a single-piece fibrous blank (100) by three-dimensional weaving between warp yarns (101) and weft yarns (102), the single-piece fibrous blank comprising an airfoil portion (111) and a root portion (112) comprising a non-interlaced body (120), the root portion (112) comprising at least one variation sub-zone (Z1b) in which the number of weft yarns crossing on both sides of the non-interlaced body (120) gradually increases from the airfoil portion (111) to the free end of the root portion (112); - shaping the fibrous blank (100) to obtain a fibrous preform (1); - densifying the preform (1) by a matrix to obtain a propeller blade or a vane made of composite material.

Description

Technical Field

[0001] This invention relates to the field of propeller blades or guide vanes for aircraft, such as those present on turboprop engines. Background Technology

[0002] Propeller blades or guide vanes used in turboprop engines are typically made of metal. While propeller blades or guide vanes made of metal have good mechanical strength, they also have the disadvantage of relatively large mass.

[0003] To obtain lighter propeller blades or guide vanes, it is known that propeller blades or guide vanes can be made from composite materials, that is, by using fiber reinforcements that are densified from a matrix to manufacture structural components.

[0004] The next generation of engines requires more compact blade or guide vane roots. This requirement stems from the need to enable blades or guide vanes to pivot around their vertical axis to adapt their incidence to flight conditions. This requirement, combined with the fact that blades or guide vanes must be integrated as low as possible onto the disk, necessitates a significant reduction in root volume.

[0005] For this reason, the roots of the new generation of blades or guide vanes have an axisymmetric or substantially axisymmetric shape and a reduced size, which is different from the roots of the prior art (e.g., the roots described in documents US2013 / 272893 and US2013 / 0017093, which extend over the entire width of the lower part of the blade or guide vane).

[0006] Such axisymmetric or quasi-axisymmetric shapes are more difficult to manufacture with composite materials, especially when using three-dimensional weaving to form fiber reinforcements for blades or guide vanes.

[0007] Furthermore, the mechanical loads on the new generation root will impose additional stress. In fact, in addition to the commonly encountered tensile and bending mechanical loads (caused by centrifugal force and impact, respectively), the new generation root may be subjected to significant bending vibration loads because there is no nacelle around the blades or guide vanes to regulate airflow. To resist this alternating bending moment, prestress is applied to the root in the hub, which generates additional mechanical loads in circumferential compression. Summary of the Invention

[0008] Therefore, it is desirable to propose a solution that enables aircraft propeller blades or guide vanes made of composite materials to withstand a variety of mechanical loads, especially at the root level where the size is reduced.

[0009] Therefore, the present invention provides a method for manufacturing propeller blades or guide vanes made of composite materials, the propeller blades or guide vanes comprising fiber reinforcements densified by a matrix, the method comprising:

[0010] A single fiber preform is manufactured by three-dimensional weaving between multiple warp and weft yarns. The fiber preform has a flat shape, wherein the warp yarns extend in a longitudinal direction corresponding to the spanwise direction of the propeller blade or guide vane to be manufactured, and wherein the weft yarns extend in a transverse direction corresponding to the chordwise direction of the propeller blade or guide vane to be manufactured. The fiber preform includes an airfoil portion and a root portion, which are used to form at least a portion of the fiber reinforcement of the airfoil and root of the propeller blade or guide vane, respectively.

[0011] - The fiber preform is shaped to obtain a single fiber preform, the single fiber preform comprising an airfoil preform formed from the airfoil portion of the fiber preform and a root preform formed from the root portion of the fiber preform.

[0012] - The fiber preform is densified by a matrix to obtain a propeller blade or guide vane made of composite material, the propeller blade or guide vane having a fiber reinforcement composed of the fiber preform and densified by the matrix; and forming a single piece with an integrated root.

[0013] The fiber preform is characterized in that the root portion includes a first non-interlaced body defining a first inner shell extending in a longitudinal direction, the first inner shell opening at the free end of the root portion, and the root portion includes at least one variation sub-region extending from the airfoil portion, wherein multiple weft yarns located inside the root portion of the fiber preform cross on both sides of the first non-interlaced body in the transverse direction, and the number of weft yarns crossing on both sides of the first non-interlaced body in the variation sub-region gradually increases from the airfoil portion to the free end of the root portion.

[0014] "Weft yarn located inside the root portion" or "internal weft yarn" refers to weft yarn that is not present on the surface of the root portion of the fiber blank.

[0015] It is believed that fiber blanks made by three-dimensional weaving can have two-dimensional weaving or other weavings incorporated into their surface in a well-known manner to improve their surface condition.

[0016] By crossing the weft yarns at the horizontal level at the root of the fiber blank, a certain circumferential stiffness can be imparted to the root of the blade. Therefore, the root of the blade will not only be able to resist ordinary tensile and bending forces, but also circumferential compression.

[0017] Therefore, the blade will have high circumferential stiffness at the root level where it is highly susceptible to circumferential compression, and high lateral stiffness at the airfoil level where it is almost unaffected by circumferential compression but is subjected to higher bending and tensile stresses.

[0018] More generally, the continuity of the three-dimensional weave between the root portion and the airfoil facilitates the transmission of various forces without creating a weak mechanical interface. Furthermore, by gradually reducing the number of intersecting weft yarns as one approaches the airfoil portion and moves away from the free end of the root portion, a smooth transition is ensured between the end of the root portion (which will have high circumferential stiffness) and the airfoil portion (which will have considerable lateral stiffness).

[0019] According to a particular feature of the invention, the root portion further includes an end sub-region extending between the free end of the root portion and the variation sub-region, and wherein all the inner weft yarns cross on both sides of the first non-interlaced body along the transverse direction.

[0020] This weaving pattern ensures the robustness of the blade root manufactured from the blank by guaranteeing excellent circumferential stiffness at the level most susceptible to circumferential compression at the root end. Furthermore, the variation sub-regions also enable a smoother transition between the end sub-region (where the intersection of all the internal yarns provides the primary circumferential stiffness) and the airfoil portion (where the stiffness is transverse).

[0021] According to a specific feature of the invention, the airfoil portion of the fiber preform includes a second non-interlaced body and a third non-interlaced body, the second non-interlaced body and the third non-interlaced body defining a second inner shell and a third inner shell opening on the same edge of the airfoil portion of the preform on both sides of the root portion of the fiber preform along the transverse direction.

[0022] These non-interlaced structures allow for the insertion of transient or lightweight insert elements into the preform to achieve lighter propeller blades or guide vane airfoils while maintaining substantially the same mechanical strength. Furthermore, since the looms used to manufacture the fiber preforms do not allow for the production of very thick roots or airfoils, the insert elements can increase the thickness of the root or airfoil portion without reducing the volume ratio of the yarn in areas subjected to high mechanical loads.

[0023] According to a particular feature of the invention, the first non-interlaced body further extends into the airfoil portion of the fiber blank.

[0024] Therefore, the fiber preform includes an inner shell present in both the root portion and the airfoil portion. Thus, the insert element inserted by the first non-interlaced body also allows for increased thickness of the airfoil portion while maintaining a constant warp-to-weft ratio and a high volume ratio of warp yarns in the region of high bending load around the insert. In fact, the loom used to manufacture the fiber preform does not allow for the production of very thick roots or airfoils.

[0025] According to a specific feature of the invention, in the airfoil portion of the fiber preform, a maximum of six weft yarns on each plane cross along the transverse direction on both sides of the first non-interlaced body. Preferably, in the airfoil portion of the fiber preform, only two weft yarns on each plane cross along the transverse direction on both sides of the first non-interlaced body.

[0026] Therefore, a blade is obtained that allows for a very gradual evolution of stiffness orientation from the root end to the tip: the stiffness is primarily circumferential at the blade root, then mixed in the lower portion of the airfoil including the first non-interlaced body, and finally primarily lateral in the upper portion of the airfoil excluding the first non-interlaced body. Thus, the transition between the predominant circumferential stiffness at the root and the predominant lateral stiffness in the upper portion of the airfoil is smoother by means of a transition region in the lower portion of the airfoil including the first non-interlaced body.

[0027] According to a particular feature of the invention, the fiber preform is made by three-dimensional weaving with interlocking weaving.

[0028] Using three-dimensional weaving with interlocking weaving can also reduce the risk of delamination within blades or propellers.

[0029] It is believed that the fiber blank made by three-dimensional weaving with interlocking weaving can include another weaving, such as two-dimensional or multi-satin weaving, on its surface in order to improve its surface condition.

[0030] According to another specific feature of the invention, the forming of the fiber preform is performed by inserting an inserting element into each non-interlaced part of the fiber preform.

[0031] The present invention also relates to a propeller blade or guide vane made of a composite material, the propeller blade or guide vane comprising a fiber reinforcement densified by a matrix, the propeller blade or guide vane including a root and an airfoil in a longitudinal direction and extending in a transverse direction between a leading edge and a trailing edge, the fiber reinforcement including a fiber preform having a single-piece three-dimensional weave between multiple warp yarns extending in the longitudinal direction and multiple weft yarns extending in the transverse direction, the fiber preform comprising: a root preform of the propeller blade or guide vane present in the root and an airfoil preform of the airfoil, the present invention further comprising: a root preform of the propeller blade or guide vane present in the root and an airfoil preform of the airfoil. The propeller blade or guide vane is characterized in that the root preform of the fiber preform includes a first non-interlaced body defining a first inner shell, the first inner shell forming a cavity opening at the free end of the root, and the root preform includes at least one variation portion extending from the airfoil preform, wherein multiple weft yarns located inside the root preform cross on both sides of the first inner shell in the transverse direction, and the number of weft yarns crossing on both sides of the first inner shell in the transverse direction in the variation portion gradually increases from the airfoil preform to the free end of the root preform.

[0032] According to a particular feature of the invention, the root preform further includes an end portion extending between the free end of the root preform and the variation portion, wherein all the inner weft yarns cross on both sides of the first inner housing along the transverse direction.

[0033] According to a specific feature of the invention, the airfoil preform of the fiber preform includes a second non-interlaced body and a third non-interlaced body, the two interlaced bodies defining a second inner shell and a third inner shell opening on the same edge of the airfoil preform on both sides of the root preform along the transverse direction.

[0034] According to another specific feature of the invention, the first inner shell also extends into the airfoil preform of the fiber preform.

[0035] According to another specific feature of the invention, in the airfoil preform of the fiber preform, a maximum of six weft yarns on each plane cross along the transverse direction on both sides of the first inner shell. Preferably, in the airfoil preform of the fiber preform, only two weft yarns on each plane cross along the transverse direction on both sides of the first inner shell. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating the 3D weaving of fiber preforms used to manufacture blades.

[0037] Figure 2 yes Figure 1 A schematic diagram of the area of ​​the fiber preform.

[0038] Figure 3 This is an example Figure 2 A schematic diagram of the fiber blank being woven along the cutting plane III-III.

[0039] Figure 4 This is an example Figure 2 A schematic diagram of the fiber preform woven along the cutting plane IV-IV.

[0040] Figure 5 This is an example Figure 2 A schematic diagram of the fiber preform woven along the cutting plane VV.

[0041] Figure 6 This is an example Figure 2 A schematic diagram of the fiber preform woven along the cutting plane VI-VI.

[0042] Figure 7 This is an exploded perspective view showing an injection molding tool and a [device] from which an [object] will be [operated / delivered] according to an embodiment of the present invention. Figures 1 to 6 The fiber preform obtained from the fiber preform is placed inside it.

[0043] Figure 8 It shows Figure 7 A perspective view of the closed injection molding tool.

[0044] Figure 9 This is a cross-sectional schematic diagram illustrating a flexible film injection molding tool and a [tool] from which a [material] is to be injected according to an embodiment of the present invention. Figures 1 to 6 The fiber preform obtained from the fiber blank is placed inside it. Detailed Implementation

[0045] This invention is generally applicable to various types of propeller blades or guide vanes used in aircraft engines. It has advantageous, but not exclusive, applications in large propeller blades or guide vanes integrated into pivoting or variable pitch systems.

[0046] Such propeller blades or guide vanes are typically provided with a root that has a small volume and good strength against tensile, bending, and circumferential compressive forces. The blades according to the invention can be specifically configured for use (e.g., in aircraft engines known as “open rotor” engines) as blades for unducted moving wheels.

[0047] In the remainder of this description, exemplary embodiments are described with respect to the blades of a turboprop engine. However, these exemplary embodiments are also applicable to aircraft propeller guide vanes.

[0048] Figure 1 The fiber blank 100 for forming the fiber preform 1 to be manufactured blades is shown in a very schematic manner.

[0049] like Figure 1 As illustrated, the fiber structure preform 100 is obtained by three-dimensional (3D) weaving in a known manner using a jacquard loom, on which a bundle of warp yarns 101 or strands has been arranged in multiple layers of several hundred yarns per layer, the warp yarns being interwoven with weft yarns 102. The fiber structure preform 100 is woven into a single piece along a longitudinal direction D corresponding to the spanning direction of the blade to be manufactured. L Extending, and between the leading edge 100a and the trailing edge 100b along a transverse direction D corresponding to the chordal direction of the blade to be manufactured. T extend.

[0050] The blank 100 includes an airfoil portion 111, which is used to form a portion of the airfoil for subsequent blade formation, and defines a first surface 111e and a second surface 111f for forming the outer and inner arcuate surfaces of the blade, respectively. Therefore, the airfoil portion 111 extends along the longitudinal direction D between its lower edge 100c and upper edge 100d. L extend.

[0051] The fiber preform 100 also includes a root portion 112, which is used to subsequently form part of the blade root and is located in the longitudinal direction D. L Extending to the outside of the airfoil portion 111, reaching the lower edge 102c, and along the lateral direction D T It recedes inward from the leading edge 100a and the trailing edge 100b. The lower edge 102c of the root portion 112 corresponds to the free end of the root portion 112.

[0052] Preferably, as illustrated in the example, the 3D weaving is an "interlocking" weaving. Here, "interlocking" weaving refers to a weaving in which each layer of weft yarns interweaves with multiple layers of warp yarns, and all yarns in the same weft row have the same movement within the weaving plane.

[0053] Other known types of three-dimensional weaving can be used, such as those described in particular in document WO 2006 / 136755. In particular, this document describes the manufacture of reinforcing fiber structures for components such as blades by weaving them into single pieces, having a first type of core weaving and a second type of skin weaving, which can impart the desired mechanical and aerodynamic properties to this type of component.

[0054] The fiber preform 100 may comprise various types of yarns, particularly ceramic or carbon yarns or mixtures thereof. Preferably, the fiber preform 100 may be made of silicon carbide fibers. Typically, the fiber preform 100 may also be made of fibers composed of: alumina, mullite, silica, aluminosilicate, borosilicate, carbon, or mixtures of several of these materials.

[0055] When weaving fiber blanks 100 with varying thicknesses and widths, a specific number of warp yarns are not woven, which can define the required continuously variable profile and thickness of the blank 100. An example of altering the 3D weave is described in document US2006 / 257260, specifically allowing the thickness of the blank 100 to vary between a first edge forming the leading edge and a thinner second edge forming the trailing edge. Preferably, the thickness of the trailing or leading edge is reduced by removing a weft layer present inside rather than outside the fiber blank to maintain the continuity of the weft yarns on the surface of the fiber blank. Therefore, the final blade will include a lateral direction D... T Fiber-reinforced members have more satisfactory bending stiffness, and are therefore more advantageous under impact conditions, such as bird strikes.

[0056] According to the invention, during the weaving process, a first non-interlaced body 120 is formed at least inside the root portion 112 of the fiber preform 100. Preferably, three non-interlaced bodies are formed inside the fiber preform 100. Specifically, a second non-interlaced body 110 is formed inside the airfoil portion 111 of the fiber preform 100, and a third non-interlaced body 130 is formed inside the airfoil portion 111 of the fiber preform 100. The three non-interlaced bodies 110, 120, and 130 extend along a plane parallel to the surface of the preform 100. The second non-interlaced body 110 and the third non-interlaced body 130 formed inside the airfoil portion 111 are located on both sides of the first non-interlaced body 120 formed at least inside the root portion 112. Therefore, the second non-interlaced body 110, the first non-interlaced body 120, and the third non-interlaced body 130 are aligned in the transverse direction D. T Arrange them in this order.

[0057] The first non-interlaced body 120 extends in the fiber blank 100 over a first non-interlaced region defined by profile 120a. Therefore, the first non-interlaced body 120 extends in the root portion 112 over at least a first portion of a second non-interlaced region defined by profile 120a. Thus, the first non-interlaced body 120 extends through the root portion 112 of the blank 100.

[0058] In the root portion 112 of the blank 100, the first non-interlaced body 120 extends in the transverse direction D between the leading edge 100a and the trailing edge 100b. TExtension. Preferably, the first non-interlaced body 120 extends inward from the leading edge 100a and the trailing edge 100b, that is, the first non-interlaced body 120 does not open onto the leading edge 100a and the trailing edge 100b.

[0059] In the root portion 112 of the blank 100, the first non-interwoven body 120 extends longitudinally along the direction D between the lower edge 100c of the airfoil portion 111 and the lower edge 102c of the root portion. L It extends and opens to the lower edge 102c of the root portion. The first non-interwoven body 120 may extend inward from the lower edge 100c of the airfoil portion 111, that is, it does not open into the airfoil portion 111 of the blank 100.

[0060] However, preferably, the first non-interlaced body 120 also extends into the airfoil portion 111 of the blank 100. Thus, the first non-interlaced body 120 extends into the airfoil portion 111 over a second portion of the first non-interlaced region defined by the profile 120a.

[0061] In this case, in the airfoil portion 111, the first non-interlaced body 120 extends in the lateral direction D between the leading edge 100a and the trailing edge 100b. T Extension. Preferably, the first non-interlaced element 120 extends inward from the leading edge 100a and the trailing edge 100b, that is, the first non-interlaced element 120 does not open onto the leading edge 100a and the trailing edge 100b. If the first non-interlaced element 120 opens onto the leading edge 100a and / or the trailing edge 100b, it will certainly not deviate from the framework of the invention. Furthermore, in the airfoil portion 111, the first non-interlaced element 120 extends longitudinally in the direction D between the lower edge 100c and the upper edge 100d. L Extending. Clearly, the first non-interlaced body 120 opens onto the lower edge 100c so as to open into the root portion 112. Preferably, the first non-interlaced body 120 is along the longitudinal direction D. L Extending inward from the upper edge 100d, that is, the first non-interwoven body 120 does not open to the upper edge 100d.

[0062] Therefore, as Figure 3 As illustrated, the first non-woven body 120 partially divides the root portion 112 into two woven portions 112a and 112b, which are along the thickness direction of the blank 100 (that is, along the transverse direction D). T and longitudinal direction D L (Vertically) arranged on both sides of the first non-interlaced body 120. In the illustrated example, as... Figure 5As illustrated, the first non-woven body 120 partially divides the airfoil portion 111 into a fifth woven portion 114a and a sixth woven portion 114b, which are woven portions along the thickness direction of the blank 100 (that is, along the transverse direction D). T and longitudinal direction D L The vertical direction) is arranged on both sides of the first non-interlaced body 120.

[0063] The second non-interlaced body 110 extends over the second non-interlaced region defined by the profile 110a into the airfoil portion 111. Thus, the non-interlaced body 110 partially divides the airfoil portion 111 into a first woven portion and a second woven portion, the first woven portion including a portion of a first surface 111e for forming an outer arcuate surface, and the second woven portion including a portion of a second surface 111f for forming an inner arcuate surface.

[0064] The second non-interlaced body 110 is located in the lateral direction D between the leading edge 100a and the trailing edge 100b. T Extending and receding inward from the trailing edge 100b, that is, the second non-interlaced body 110 does not open onto the trailing edge 100b. Preferably, the second non-interlaced body 110 extends in the transverse direction D. T Extending inward from the leading edge 100a, that is, the second non-interlaced body 110 does not open onto the leading edge 100a. Preferably, any point belonging to the second non-interlaced body 110 extends along the lateral direction D. T It is closer to the leading edge 100a than the trailing edge 100b.

[0065] In the airfoil portion 111, the second non-interwoven body 110 extends longitudinally along the direction D between the lower edge 100c and the upper edge 100d. L Extending. The second non-interlaced body 110 opens onto the lower edge 100c, and the second non-interlaced body 110 opens onto the lower edge 100c between the junction of the leading edge 100a and the root portion 112 and the airfoil portion 111. Preferably, the second non-interlaced body 110 is along the longitudinal direction D. L Extending inward from the upper edge 100d, that is, the first non-interwoven body 110 does not open to the upper edge 100d.

[0066] Therefore, the second non-woven body 110 partially divides the airfoil portion 111 into two woven portions 111a and 111b, which are along the thickness direction of the blank 100 (that is, along the transverse direction D). T and longitudinal direction D L The vertical direction) is arranged on both sides of the second non-interlaced body 110.

[0067] The third non-interlaced body 130 extends in the airfoil portion 111 over the third non-interlaced region defined by the profile 130a. Thus, the non-interlaced body 130 partially divides the airfoil portion 111 into a first woven portion and a second woven portion, the first woven portion including a portion of a first surface 111e for forming an outer arcuate surface, and the second woven portion including a portion of a second surface 111f for forming an inner arcuate surface.

[0068] The third non-interlaced body 130 is located in the lateral direction D between the leading edge 100a and the trailing edge 100b. T Extending and receding inward from the leading edge 100a, that is, the third non-interlaced body 130 does not open onto the leading edge 100a. Preferably, the third non-interlaced body 130 is along the transverse direction D. T Extending inward from the trailing edge 100b, that is, the third non-interlaced body 130 does not open onto the trailing edge 100b. Preferably, any point belonging to the third non-interlaced body 130 extends along the transverse direction D. T It is closer to the trailing edge 100b than the leading edge 100a.

[0069] In the airfoil section 111, the third non-interwoven body 130 extends longitudinally along the direction D between the lower edge 100c and the upper edge 100d. L Extending. The third non-interlaced body 130 opens onto the lower edge 100c, and the second non-interlaced body 130 opens onto the lower edge 100c between the trailing edge 100b and the junction between the root portion 112 and the airfoil portion 111. Preferably, the third non-interlaced body 130 extends along the longitudinal direction D. L Extending inward from the upper edge 100d, that is, the non-interwoven body 110 does not open to the upper edge 100d.

[0070] Therefore, as Figure 5 As illustrated, the third non-woven body 130 partially divides the airfoil portion 111 into two woven portions 113a and 113b, which are along the thickness direction of the blank 100 (that is, along the transverse direction D). T and longitudinal direction D L (Vertical direction) arranged on both sides of the third non-interwoven body 130.

[0071] Preferably, in the airfoil portion 111, the second non-interlaced body 110 and the third non-interlaced body 130 are along the longitudinal direction D L The extended length is longer than the first non-interwoven body 120.

[0072] Therefore, as Figure 2 As illustrated, the fiber preform 100 consists of several continuous regions that span the fiber preform 100 in the transverse direction D. T The entire width extends, and along the longitudinal direction DL They are consecutive to each other.

[0073] The first region Z1 of the fiber preform 100 corresponds to the region of the root portion 112 of the fiber preform 100. Therefore, the first region Z1 spans the root portion 112 of the fiber preform 100 in the transverse direction D. T The entire width extends, and extends between the lower edge 102c of the root portion 112 and the lower edge 100c of the airfoil portion 111. Therefore, the first region Z1 comprises only: a first non-interlaced body 120 as a single non-interlaced body.

[0074] The first region Z1 includes a first sub-region Z1a, referred to as the "end sub-region," which includes the free end of the root portion 112, that is, the first sub-region Z1a extends from the lower edge 102c of the root portion 112. The first region Z1 also includes a second sub-region Z1b, referred to as the "variation sub-region," which extends from the lower edge 100c of the airfoil portion 111. Preferably, the first sub-region Z1a and the second sub-region Z1b are adjacent and extend along the longitudinal direction D. L They follow each other. Preferably, when the root portion 112 has such Figure 2 When the hourglass shape is illustrated, the smaller thickness of the cross section of the hourglass (which corresponds to the neck of the leaf root portion 112) forms the boundary between the first sub-region Z1a and the second sub-region Z1b.

[0075] When the first non-interlaced body 120 also extends into the airfoil portion 111, the second region Z2 corresponds to the region of the guide vane airfoil portion 111 where the three non-interlaced bodies 110, 120, and 130 exist. Therefore, the second region Z2 spans the airfoil portion 111 of the fiber blank 100 in the lateral direction D. T The entire width extends, and extends from the lower edge 100c of the airfoil portion 111. Therefore, as... Figure 2 As shown, if present, the second region Z2 includes: a second non-interlaced body 110, a first non-interlaced body 120, and a third non-interlaced body 130.

[0076] The third region Z3 of the fiber preform 100 corresponds to the region of the guide vane airfoil portion 111 where two non-interwoven bodies exist (if such a region exists). Preferably, as Figure 2As illustrated in the example, the third region corresponds to the region of the guide vane airfoil portion 111 where the second non-interlaced body 110 and the third non-interlaced body 130 exist, and the first non-interlaced body 120 does not extend beyond the first region Z1 or the second region Z2. Of course, if the third region Z3 corresponds to the region of the guide vane airfoil portion 111 where the second non-interlaced body 110 and the first non-interlaced body 120 or the region where the first non-interlaced body 120 and the third non-interlaced body 130 exist (if such region exists), then there is no departure from the framework of the invention.

[0077] The fourth region Z4 of the fiber preform 100 corresponds to the region of the guide vane airfoil portion 111 where only a single non-interwoven element exists (if such a region is present). Preferably, as in Figure 2 In the example case, the fiber preform 100 does not include the fourth region Z4. If the fiber preform 100 includes the fourth region Z4, then the fourth region Z4 includes either the second non-interlaced body 110 or the third non-interlaced body 130. However, if the fourth region Z4 corresponds to the region of the guide vane airfoil portion 111 where only the first non-interlaced body 120 exists (if that region is present), then there is no departure from the framework of the invention.

[0078] The fifth region Z5 of the fiber preform 100 corresponds to the region of the airfoil portion 111 that does not contain any non-interwoven parts. Therefore, the fifth region Z5 spans the airfoil portion of the fiber preform 100 in the lateral direction D. T It extends across the entire width and extends to the upper edge 100d of the airfoil portion 111.

[0079] Figures 3 to 6 The diagram schematically illustrates a 3D weaving pattern of interlocking weave of the first blank 100 according to the present invention. For simplicity, the number of weft yarns shown has been reduced.

[0080] Figure 3 It is the warp cross section in the first sub-region Z1a of the first region Z1 of the fiber blank 100. Figure 2 A partially enlarged view of section III-III in the image. In this example, the fiber preform 100 includes: substantially along the longitudinal direction D L Eight layers of warp yarns 101 are extended. In the interlacing regions 115 and 125 of the root portion 112 of the fiber preform 100, the eight layers of warp yarns 101 are interlaced by weft yarns T1 to T8, which are substantially along the transverse direction D. T extend.

[0081] The eight warp yarns 101 are divided into: a first group of 108 yarn layers 101 and a second group of 109 yarn layers 101. The first group of 108 and the second group of 109 warp yarn layers 101 are arranged along the thickness direction (that is, along the direction perpendicular to the transverse direction D). T and longitudinal direction DL The warp yarns (in the direction of the yarns) are arranged on both sides of the first non-woven body 120. Therefore, the first woven portion 112a of the root portion 112 includes a portion of the warp yarns 101 of the first group 108, and the second woven portion 112b of the root portion 112 includes a portion of the warp yarns of the second group 109. The warp yarn layers of the first group 108 and the second group 109 are connected in the interlacing regions 115 and 125.

[0082] like Figure 3 As illustrated, in the first sub-region Z1a of the first region Z1, all the inner layer weft yarns T2 to T7 cross on both sides of the first non-interlaced body 120 in the transverse direction. On the other hand, the outer layer weft yarns T1 and T8 (that is, those located on the surface of the fiber blank 100) do not cross with the weft yarns of other layers in order to ensure a better surface condition. Of course, if all the inner and outer layer weft yarns cross on both sides of the first non-interlaced body 120 in the transverse direction, it will not deviate from the framework of the invention.

[0083] Therefore, in the first sub-region Z1a of the first region Z1, each inner weft yarn intersects with other weft yarns in the first interlacing region 115 and the second interlacing region 125. Thus, all inner weft yarns in the transverse direction D T The first non-interlaced body 120 deflects at the starting point or upstream, and then deflects along the lateral direction D. T The first non-interlaced layer 120 is deflected again at its exit or downstream. Therefore, the weft yarn layers T2 to T4 interlace with the warp yarns 101 of the first group 108 in the first interlacing region 115, then with the warp yarns 101 of the second group 109 in the second weaving section 112b, and finally with the warp yarns 101 of the first group 108 in the second interlacing region 125. Conversely, the weft yarn layers T5 to T7 interlace with the warp yarns 101 of the second group 109 in the first interlacing region 115, then with the warp yarns 101 of the first group 108 in the first weaving section 112a, and finally with the warp yarns 101 of the second group 109 in the second interlacing region 125.

[0084] This crossing of the weft yarns at the root portion 112 improves the retention of the fiber blank 100 around the first non-interlaced body 120 and subsequently allows for excellent circumferential stiffness to be imparted to the leaf root.

[0085] The first region Z1 further includes a second sub-region Z1b extending from the lower edge 100c of the airfoil portion 111. This second sub-region Z1b enables a transition between (on the one hand) the first sub-region Z1a and (on the other hand) the airfoil portion, in which all internal weft yarns intersect, whereas the percentage of intersecting weft yarns in the airfoil portion is very small. Therefore, the second sub-region Z1b has a longitudinal direction D LThe weft cross percentage varies gradually on both sides of the first non-interlaced body 120. More specifically, the second sub-region Z1b has a gradually decreasing weft cross percentage from the first sub-region Z1a of the root portion 112 to the airfoil portion 111. Therefore, an abrupt transition between the root portion 112 and the airfoil portion 111 is avoided. Thus, a blade is obtained with a gradually evolving stiffness orientation between the root and the airfoil: the stiffness is strong circumferentially at the tip of the blade root, decreasing towards the airfoil portion and increasing towards the lateral direction. However, compared to the stiffness of the airfoil, the stiffness at the blade root is still greater circumferentially and less laterally. Therefore, the transition between the main circumferential stiffness at the root tip and the main lateral stiffness in the upper portion of the airfoil is smoother.

[0086] Figure 4 It is the warp cross section in the second sub-region Z1b of the first region Z1 of the fiber blank 100. Figure 2 A partially enlarged view of section IV-IV in the first region Z1. In the second sub-region Z1b of the first region Z1, eight layers of warp yarns 101 pass through the weft yarn T in the interlacing regions 115 and 125 of the root portion 112 of the fiber blank 100. t1 To T t8 Interweaving, weft T t1 To T t8 Basically along the horizontal direction D T extend.

[0087] like Figure 4 As illustrated, in the second sub-region Z1b of the first region Z1, only the inner weft yarn T... t2 To T t7 A portion crosses on both sides of the first non-interlaced yarn 120 in the transverse direction. The outer weft yarn T... t1 and T t8 (That is, those located on the surface of the fiber blank 100) do not cross with the weft yarns of other layers in order to ensure a better surface condition.

[0088] Therefore, in the second sub-region Z1b of the first region Z1, only a certain percentage of the internal weft yarns intersect with other weft yarns in the first interlacing region 115 and the second interlacing region 125. Thus, only a portion of the internal weft yarns intersect with other weft yarns in the transverse direction D. T The first non-interlaced body 120 deflects at the starting point or upstream, and then deflects along the lateral direction D. T The first non-interwoven body 120 deflects again at the outlet or downstream.

[0089] Therefore, weft yarn T t3 and T t4The layer interweaves with the warp yarns 101 of the first group 108 in the first interweaving area 115, then with the warp yarns 101 of the second group 109 in the second weaving section 112b, and finally with the warp yarns 101 of the first group 108 in the second interweaving area 125. Conversely, the weft yarn T... t5 and T t6 The layer interweaves with the warp yarns 101 of the second group 109 in the first interweaving region 115, then with the warp yarns 101 of the first group 108 in the first weaving section 112a, and finally with the warp yarns 101 of the second group 109 in the second interweaving region 125. Figure 4 In the example illustrated, for the sake of simplicity, only four weft yarns cross on both sides of the first non-interlaced body 120. Preferably, more weft yarns cross on both sides of the first non-interlaced body 120 to ensure sufficient circumferential stiffness at the future blade root.

[0090] Preferably, in the second sub-region Z1b of the first region Z1, the percentage of the inner weft yarns crossing on both sides of the first non-interlaced body 120 gradually changes from 100% at the junction with the first sub-region Z1a to 5% to 30% at the junction with the airfoil portion 111.

[0091] Figure 5 It is the warp cross section in the second region Z2 of the fiber preform 100. Figure 2 A partially enlarged view of the VV section (in the image). In the second region Z2, eight layers of warp yarns 101 pass through the weft yarn T in the interlacing regions 105, 115, 125, and 135 of the airfoil portion 111 of the fiber blank 100. 11 To T 18 Interweaving, weft T 11 To T 18 Basically along the horizontal direction D T extend.

[0092] The first group of 108 warp yarns, layer 101, and the second group of 109 warp yarns, layer 101, are along the thickness direction (that is, along the transverse direction D). T and longitudinal direction D L The vertical direction) is arranged on both sides of the second non-interlaced body 110, the first non-interlaced body 120 and the third non-interlaced body 130.

[0093] Therefore, the first braided portion 111a, the third braided portion 113a, and the fifth braided portion 114a of the airfoil portion 111 each include a portion of the warp yarns 101 of the first group 108, and the second braided portion 111b, the fourth braided portion 113b, and the sixth braided portion 114b of the airfoil portion 111 each include a portion of the warp yarns of the second group 109. The warp yarn layers 101 of the first group 108 and the second group 109 are connected in interlacing regions 105, 115, 125, and 135.

[0094] The first interlacing region 115 separates the second non-interlacing body 110 from the first non-interlacing body 120. The second interlacing region 125 separates the first non-interlacing body 120 from the third non-interlacing body 130. The third interlacing region 105 includes a portion of the leading edge 100a. The fourth interlacing region 135 includes a portion of the trailing edge 100b. Therefore, the third interlacing region 105, the second non-interlacing body 110, the first interlacing region 115, the first non-interlacing body 120, the second interlacing region 125, the third non-interlacing body 130, and the fourth interlacing region 135 are arranged in this order along the lateral direction D. T They are continuous with each other in the second region Z2.

[0095] like Figure 5 As illustrated, each plane has only two weft yarns T14 and T15 intersecting. These two yarns are located at the core of the airfoil portion 111 and are substantially in the transverse direction D along the boundaries of the first non-interlaced body 120, the second non-interlaced body 110, and the third non-interlaced body 130. T Passing through airfoil section 111. Preferably, each plane has a maximum of six weft yarns, which preferably intersect in the second region Z2 along the boundaries of the first non-interlaced body 120, the second non-interlaced body 110 and the third non-interlaced body 130.

[0096] exist Figure 5 In the example illustrated, for simplicity, the space between each non-interlaced element 110, 120, 130 is very limited. Preferably, a larger space can be maintained between each non-interlaced element 110, 120, 130 to allow for proper three-dimensional weaving of the fibers. Additional weft yarns can be inserted into these spaces between the non-interlaced elements 110, 120, 130 to compensate for insufficient thickness due to the absence of non-interlaced elements.

[0097] Therefore, in the second region Z2, the two weft yarns T 14 T 15 They intersect at least in the first interlacing region 115 and the second interlacing region 125. Preferably, as shown... Figure 5 As illustrated in the example, two weft yarns T 14 T 15 They also intersect in the third interlacing region 105 and the fourth interlacing region 135. Therefore, the two weft yarns T 14 T 15 Along the lateral direction D T The first non-interlaced body 120 deflects at the starting point or upstream, and then deflects along the lateral direction D. T The first non-interwoven body 120 deflects again at the outlet or downstream.

[0098] Therefore, weft yarn T 11 To T 13The transverse direction D of the airfoil section 111 T The entire width is interwoven with the warp yarns 101 of the first group 108. Therefore, the weft yarn T 11 To T 13 It interweaves with the warp yarns 101 of the first group 108 in the third interweaving area 105, the first weaving section 111a, the first interweaving area 115, the fifth weaving section 114a, the second interweaving area 125, the third weaving section 113a and the fourth interweaving area 135.

[0099] Conversely, weft yarn T 16 To T 18 The transverse direction D of the airfoil section 111 T The entire width is interwoven with the warp yarns 101 of the second group 109. Therefore, the weft yarn T 16 To T 18 It interweaves with the warp yarns 101 of the second group 109 in the third interweaving area 105, the second weaving section 111b, the first interweaving area 115, the sixth weaving section 114b, the second interweaving area 125, the fourth weaving section 113b and the fourth interweaving area 135.

[0100] This partial crossing of the weft yarn in the lower part of the airfoil section 111 improves the retention of the fiber blank 100 around the three non-interlaced bodies 110, 120 and 130, and subsequently enables a smooth transition between the circumferential stiffness at the blade root and the lateral stiffness at the airfoil tip by introducing a mixed stiffness between circumferential and lateral stiffness.

[0101] Figure 6 It is the warp cross section in the third region Z3 of the fiber preform 100. Figure 2 A partially enlarged view of section VI-VI in the image. In the third region Z3, eight layers of warp yarns 101 pass through the weft yarn T in the interlacing regions 105, 115, 125, and 135 of the airfoil portion 111 of the fiber blank 100. 21 To T 28 Interweaving, weft T 21 To T 28 Basically along the horizontal direction D T extend.

[0102] The warp layers 101 of the first group 108 and the second group 109 are along the thickness direction (that is, along the transverse direction D). T and longitudinal direction D L (Vertical direction) arranged on both sides of the second non-interlaced body 110 and the third non-interlaced body 130.

[0103] Therefore, the first braided portion 111a and the third braided portion 113a of the airfoil portion 111 each include a portion of the warp yarns 101 of the first group 108, and the second braided portion 111b and the fourth braided portion 113b of the airfoil portion 111 each include a portion of the warp yarns of the second group 109. The warp yarn layers 101 of the first group 108 and the second group 109 are connected in interlacing regions 105, 115, 125 and 135.

[0104] The third interlacing region 105, the second non-interlacing body 110, the common area of ​​the first interlacing region 115 and the second interlacing region 125, the third non-interlacing body 130 and the fourth interlacing region 135 are arranged in this order along the lateral direction D. T They are continuous with each other in the third region Z3.

[0105] like Figure 6 As illustrated, preferably, each plane has only two weft yarns T. 24 T 25 The two yarns intersect at the core of the airfoil portion 111 and are substantially in the transverse direction D along the boundary between the second non-interlaced section 110 and the third non-interlaced section 130. T Passing through airfoil section 111. Preferably, each plane has a maximum of six weft yarns, preferably crossing in the third region Z3 along the boundary between the second non-interlaced body 110 and the third non-interlaced body 130.

[0106] Therefore, as Figure 6 As illustrated in the example, in the third region Z3, the two weft yarns T 14 T 15 Preferably, the crossing occurs in the third non-interlaced body 105, and twice, in the common area of ​​the first interlaced region 115 and the second interlaced region 125, and in the fourth interlaced region 135.

[0107] Therefore, two weft yarns T 24 T 25 Along the lateral direction D T The second non-interlaced body 110 deflects at the starting point or upstream, and then deflects along the lateral direction D. T The second non-interlaced body 110 deflects again at the outlet or downstream, and then deflects along the lateral direction D. T The third non-interlaced body 130 deflects at the starting point or downstream, and then deflects along the lateral direction D. T The third non-interwoven body 130 deflects again at the outlet or upstream.

[0108] Therefore, weft yarn T 21 To T 23 The transverse direction D of the airfoil section 111 T The entire width is interwoven with the warp yarns 101 of the first group 108. Therefore, the weft yarn T 21To T 23 It interweaves with the warp yarns 101 of the first group 108 in the third interweaving region 105, the first weaving section 111a, the first interweaving region 115 and the second interweaving region 125, the third weaving section 113a and the fourth interweaving region 135.

[0109] Conversely, weft yarn T 26 To T 28 The transverse direction D of the airfoil section 111 T The entire width is interwoven with the warp yarns 101 of the second group 109. Therefore, the weft yarn T 26 To T 28 The warp yarns 101 of the second group 109 are interwoven in the third interweaving region 105, the second weaving section 111b, the first interweaving region 115 and the second interweaving region 125, the fourth weaving section 113b and the fourth interweaving region 135.

[0110] This partial crossing of the weft yarn in the middle part of the airfoil section 111 improves the retention of the fiber blank 100 around the two non-interlaced bodies 110 and 130, and subsequently enables a smoother transition between the circumferential stiffness at the blade root and the lateral stiffness at the airfoil tip by introducing a mixed stiffness between circumferential and lateral stiffness.

[0111] In the fifth region Z5, there exists a classic three-dimensional weave, which therefore has the main lateral stiffness.

[0112] Once weaving is complete, the unwoven yarns around the fiber preform 100 are cut to extract the preform. The second non-woven body 110, the first non-woven body 120, and the third non-woven body 130 respectively form a second inner shell, a first inner shell, and a third inner shell extending into the first fiber preform 100.

[0113] In order to form the fiber preform 1 of the blade to be manufactured, the fiber blank 100 is formed. Therefore, the airfoil portion 111 of the fiber blank 100 is formed into the airfoil preform 11 of the preform 1, and the root portion 112 of the fiber blank 100 is formed into the root preform 12 of the preform 1.

[0114] Preferably, the forming of the fiber preform 100 is performed by inserting at least one first insert element 20 into the first non-interlaced body 120. Preferably, one or more second insert elements 10 and third insert elements 30 may also be inserted into the airfoil portion 111 of the fiber preform 100 via the second non-interlaced body 110 and the third non-interlaced body 130, respectively. These insert elements 10, 20, 30 may be used to form part of the final part or to be removed after the densification operation of the fiber preform 1.

[0115] Insertion elements 10, 20, and 30 may be made of foam or have at least a partial lattice structure. Insertion elements 10, 20, and 30 may also be made at least partially of transient materials (i.e., materials that can be removed mechanically, chemically, or thermally).

[0116] Insert elements 10, 20, and 30 are preferably made of non-structural materials. The mass density of insert elements 10, 20, and 30, which can be used to form part of the final blade, is lower than the mass density of the fiber preform densified by the matrix in the final blade. Insert elements 10, 20, and 30 can be made of foam (e.g., polyurethane). Insert elements 10, 20, and 30 can be made of honeycomb materials.

[0117] Insertion elements 10, 20, and 30 may be made of the same material. At least one of insertion elements 10, 20, and 30 may be made of a different material than the other one. Preferably, the second insertion element 10 and the third insertion element 30 for insertion into the second non-interlaced body 110 and the third non-interlaced body 130 are made of the same material, while the first insertion element 20 for insertion into the first non-interlaced body 120 is made of a different material.

[0118] The resulting fiber preform 1 typically has the airfoil shape of the final blade. For example, a compaction step can be performed on the fiber preform 1 to change its thickness in the longitudinal direction.

[0119] The fiber preform 1, prepared as described above, is then densified. The densification of the fiber preform 1, which forms the fiber reinforcement of the component to be manufactured, includes filling all or part of the pores of the preform with the material constituting the matrix.

[0120] This densification can be performed using a liquid process in a manner known per se. The liquid process involves impregnating a preform with a liquid composition containing a matrix material precursor. This precursor is typically in polymer form, such as a high-performance epoxy resin that may be diluted in a solvent. The preform is placed in a mold, which can be hermetically sealed with a shell having a final molded blade shape. The mold is then closed, and the liquid matrix precursor (e.g., resin) is injected into the entire shell to impregnate the entire fibrous portion of the preform.

[0121] The conversion of the precursor into the matrix (i.e., its polymerization) is performed by heat treatment (usually by heating a mold) after the removal of any solvents and crosslinking of the polymer. The preform is always held in the mold, which has a shape corresponding to the shape of the workpiece to be manufactured.

[0122] In the case of forming a carbon or ceramic matrix, the heat treatment includes pyrolyzing the precursor to transform the matrix into a carbon or ceramic matrix, depending on the precursor used and the pyrolysis conditions. For example, the liquid ceramic precursor (especially SiC) can be a resin of the polycarbosilane (PCS), polytitanium carbosilane (PTCS), or polysilazane (PSZ) type, while the liquid carbon precursor can be a resin with a relatively high coke content, such as a phenolic resin. Several consecutive cycles from impregnation to heat treatment can be performed to achieve the desired degree of densification.

[0123] According to one aspect of the invention, particularly in the case of forming an organic matrix, densification of the fiber preform can be performed using a known transfer molding method known as RTM (Resin Transfer Molding). According to this RTM method, the fiber preform is placed in a mold having the external shape of the workpiece to be manufactured. A thermosetting resin is injected into the internal space of the mold, which includes the fiber preform. Typically, a pressure gradient is established in the internal space between the resin injection point and the resin discharge hole to control and optimize the impregnation of the preform with the resin.

[0124] like Figure 7 and Figure 8 As illustrated, the injection of the liquid matrix precursor composition into the fiber preform and its conversion into a matrix is ​​performed in an injection molding tool 60, which includes a first housing 61 and a second housing 62. The first housing includes a first cavity 61a at its center that partially corresponds to the shape and size of the blade to be manufactured, and the second housing includes a second cavity 62a at its center that partially corresponds to the shape and size of the blade to be manufactured.

[0125] like Figure 8 As illustrated, once tool 60 is closed, the corresponding first mold cavity 61a and second mold cavity 62a of the first housing 61 and the second housing 62 together define an internal volume having the shape of the blade to be manufactured, and in which the fiber preform 1 is placed. Compaction of the fiber preform can be performed with tool 60 closed to obtain a defined fiber ratio in the preform. In this case, compaction pressure is applied to housings 61 and 62, for example, by a press. Compaction of the fiber preform can also be performed in separate molds before being introduced into the injection molding tool.

[0126] The tool 60 also includes means for performing the injection of a liquid matrix precursor and converting the precursor into a matrix. More specifically, in the example described herein, the first housing 61 of the tool 60 includes an injection port 61e for allowing the liquid matrix precursor composition to be injected into the fiber preform, while the second housing includes an exhaust port 62s for cooperating with a pumping system to evacuate the tool and remove air during the injection process. The injection tool 60 also includes a lower portion 63 and an upper portion 64, between which the first housing 61 and the second housing 62 are disposed, and the lower portion 63 and the upper portion 64 are equipped with heating devices. Figure 8 (Not shown in the image).

[0127] Once the mold 60 is closed, the blade is molded by impregnating the preform 1 with a heat-treated, polymerized thermosetting resin. For this purpose, a well-known injection or transfer molding method known as RTM (Resin Transfer Molding) is used. According to the RTM method, resin (e.g., thermosetting resin) is injected via the injection port 61e of the first housing 61 into the internal volume occupied by the preform 1. The ports 62s of the second housing 62 are connected to a discharge conduit held under pressure. Figure 8 (Not shown in the image). This configuration allows a pressure gradient to be established between the lower portion of the preform 1 (where resin is injected) and the upper portion of the preform 1 (located near port 62s). In this way, resin injected generally at the level of the lower portion of the preform 1 will gradually impregnate the entire preform by circulating it upwards to the discharge port 62s (through which excess resin is discharged). Of course, the first housing 61 and the second housing 62 of the tool 60 may each include multiple injection ports and multiple discharge ports.

[0128] For example, the resin used can be an epoxy resin with a temperature rating of 180°C (the highest temperature supported without loss of properties). Resins suitable for the RTM method are well known. They preferably have low viscosity to facilitate their infusion into the fibers. The choice of temperature rating and / or resin chemistry depends on the thermomechanical loads the workpiece must withstand. Once the resin has been infused into the entire reinforcement, it is polymerized by heat treatment according to the RTM method.

[0129] like Figure 9 As illustrated, densification of fiber preforms can also be performed via membrane injection in a well-known manner. This injection mode allows for complete control over the amount of resin or slurry injected, thereby ensuring an accurate and appropriate fiber volume ratio. Consequently, the mechanical properties of the resulting workpieces are improved, with minimal variation between workpieces.

[0130] A fiber preform 1 is disposed in a mold 70, which includes, on one hand, an impregnation chamber 71 in which the fiber preform is disposed for densification by a matrix through an impregnation fluid injected via an injection port 71a, and on the other hand, a compaction chamber 72 into which compressed fluid is injected via an injection port 72a to apply pressure to the fiber preform 1 during matrix densification. The impregnation chamber 71 and the compaction chamber 72 are separated by a flexible membrane 73. The membrane 73 can apply pressure to the fiber preform 1 disposed in the impregnation chamber 71, and the compressed fluid applies a pressure P to the membrane 73 to deform it, thereby in turn applying pressure to the fiber preform 1. The flexible membrane 73 is made, for example, of silicone resin.

[0131] Depending on the size, thickness, and shape of the propeller blades or guide vanes to be manufactured, different sequences of compression and impregnation fluid injection are preferably used.

[0132] For example, an impregnation fluid (e.g., resin) may first be injected into an impregnation chamber containing a fiber preform. Once the impregnation fluid injection is complete, a compressed fluid (e.g., water) is injected into a compaction chamber to apply pressure to the flexible membrane. Thus, the flexible membrane applies pressure to the fiber preform, which allows the impregnation fluid to penetrate the preform.

[0133] The preform is then subjected to heat treatment while maintaining pressure applied by the membrane to form the matrix within the pores of the fiber preform.

[0134] According to another example, the compressed fluid can be injected into the compaction chamber first. Thus, even before the impregnation fluid is injected, the pressure, which allows for the desired fiber volume ratio, has already been applied to the fiber preform via the flexible membrane. The impregnation fluid injection then begins, which can be performed while the compressed fluid is still being injected to compensate for pressure losses, especially when the impregnation fluid is a slurry. This injection sequence is described, for example, in document WO 2019 / 197757 A1.

[0135] After injection and polymerization, the blades are demolded.

[0136] Preferably, the first insert element 20 is withdrawn to obtain a hollow blade root. Alternatively, the second insert element 10 and the third insert element 30 can be withdrawn to obtain a blade airfoil that is at least partially hollow. If the insert element, made of transient material, has been inserted into the fiber preform, it can be removed during resin polymerization, or during or after blade demolding. Finally, one or more insert elements 10, 20, 30 can be retained in the blade.

[0137] The manufactured workpiece can be trimmed or processed to obtain the propeller blades or guide vanes to be manufactured.

[0138] The densification method described above allows propeller blades or guide vanes made primarily of organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC) materials to be manufactured from the fiber preforms of the present invention.

Claims

1. A method for manufacturing a propeller blade or guide vane made of a composite material, said propeller blade or guide vane comprising a fiber reinforcement densified by a matrix, said method comprising: A single fiber preform (100) is manufactured by three-dimensional weaving between multiple warp yarns (101) and multiple weft yarns (102), the fiber preform (100) having a flat shape, wherein the warp yarns (101) are in a longitudinal direction (D) corresponding to the spanwise direction of the propeller blade or guide vane to be manufactured. L ) extends, and wherein the weft yarn (102) is in a transverse direction (D) corresponding to the chordal direction of the propeller blade or guide vane to be manufactured. T The fiber preform (100) extends to include an airfoil portion (111) and a root portion (112), the airfoil portion and the root portion being used to form at least a portion of the fiber reinforcement of the airfoil and root of the propeller blade or guide vane, respectively. The fiber preform (100) is shaped to obtain a single fiber preform (1), the single fiber preform including an airfoil preform formed from the airfoil portion (111) of the fiber preform (100) and a root preform formed from the root portion (112) of the fiber preform (100). The fiber preform (1) is densified by a matrix to obtain a propeller blade or guide vane made of composite material, the propeller blade or guide vane having a fiber reinforcement composed of the fiber preform (1) and densified by the matrix; and forming a single piece with an integrated root. The fiber preform (100) is characterized in that its root portion (112) includes a first non-interlaced body (120), which defines a first inner shell and extends along the longitudinal direction (D). L The first inner shell opens at the free end (102c) of the root portion (112), and the root portion (112) includes at least one variation sub-region (Z1b) extending from the airfoil portion (111), and wherein multiple weft yarns located inside the root portion (112) of the fiber blank (100) are along the transverse direction (D). T It intersects on both sides of the first non-interlaced body (120), and in the changing sub-region (Z1b) along the lateral direction (D) T The number of weft yarns crossing on both sides of the first non-interlaced body (120) gradually increases from the airfoil portion (111) to the free end (102c) of the root portion (112).

2. The manufacturing method according to claim 1, wherein, The root portion (112) further includes an end sub-region (Z1a) extending between the free end (102c) of the root portion (112) and the variation sub-region (Z1b), wherein all inner weft yarns are along the transverse direction (D). T They cross on both sides of the first non-interlaced body (120).

3. The manufacturing method according to claim 1 or 2, wherein, The airfoil portion (111) of the fiber preform (100) includes a second non-interlaced body (110) and a third non-interlaced body (130), the second non-interlaced body and the third non-interlaced body being along the transverse direction (D). T A second inner shell and a third inner shell are defined on both sides of the root portion (112) of the fiber preform (100), opening onto the same edge of the airfoil portion (111) of the fiber preform (100).

4. The manufacturing method according to claim 1, wherein, The first non-interwoven body (120) also extends into the airfoil portion (111) of the fiber blank (100).

5. The manufacturing method according to claim 4, wherein, In the airfoil portion (111) of the fiber preform (100), each plane has a maximum of six weft yarns along the transverse direction (D). T They cross on both sides of the first non-interlaced body (120).

6. The manufacturing method according to claim 5, wherein, In the airfoil portion (111) of the fiber preform (100), each plane has only two weft yarns along the transverse direction (D). T They cross on both sides of the first non-interlaced body (120).

7. The manufacturing method according to claim 1, wherein, The fiber preform (100) is made by three-dimensional weaving with interlocking weaving.

8. The manufacturing method according to claim 3, wherein, The forming of the fiber preform (100) is performed by inserting insert elements (10, 20, 30) into each non-interlaced part (110, 120, 130) of the fiber preform (100).

9. A propeller blade or guide vane made of a composite material, said propeller blade or guide vane comprising a fiber reinforcement densified through a matrix, said propeller blade or guide vane along the longitudinal direction (D L ) includes the root and airfoil, and extends laterally between the leading and trailing edges (D T The fiber reinforcement includes a fiber preform (1) extending along the longitudinal direction (D). L The multiple warp yarns (101) extending along the said transverse direction (D) T The fiber preform (1) comprises a single piece of three-dimensional weave between multiple weft yarns (102) extending from each other, and includes: The root preform in the root of the propeller blade or guide vane and the airfoil preform in the airfoil are characterized in that the root preform of the fiber preform (1) includes a first non-interlaced body (120) defining a first inner shell, the first inner shell forming a cavity opening at the free end of the root, and the root preform includes at least one variation portion extending from the airfoil preform, and wherein multiple weft yarns located inside the root preform are along the transverse direction (D). T ) intersects on both sides of the first inner housing, and in the changing portion along the lateral direction (D) T The number of weft yarns crossing on both sides of the first inner shell gradually increases from the airfoil preform to the free end of the root preform.

10. The propeller blade or guide vane according to claim 9, wherein, The root preform further includes an end portion extending between the free end of the root preform and the variation portion, wherein all internal weft yarns are along the transverse direction (D). T They intersect on both sides of the first inner shell.

11. The propeller blade or guide vane according to claim 9 or 10, wherein, The airfoil preform of the fiber preform (1) includes a second non-interwoven body (110) and a third non-interwoven body (130), the second non-interwoven body and the third non-interwoven body being along the transverse direction (D). T A second inner shell and a third inner shell are defined on both sides of the root preform, with openings on the same edge of the airfoil preform.

12. The propeller blade or guide vane according to claim 9, wherein, The first inner shell also extends into the airfoil preform of the fiber preform (1).

13. The propeller blade or guide vane according to claim 12, wherein, In the airfoil preform of the fiber preform (1), each plane has a maximum of six weft yarns along the transverse direction (D). T They intersect on both sides of the first inner shell.

14. The propeller blade or guide vane according to claim 13, wherein, In the airfoil preform of the fiber preform (1), each plane has only two weft yarns along the transverse direction (D). T They intersect on both sides of the first inner shell.

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