Device for shaping a fibre preform for producing a blade part of a turbomachine

Abstract

The present invention relates to an apparatus (30) for forming at least one fiber preform of a turbine blade component (10), the apparatus comprising a mold (34) formed of a plurality of interlocking components defining an internal cavity (32) for integrally enclosing the preform, the cavity (32) having two platform regions (Z2, Z3) and a blade region (ZZ1) extending between the two platform regions, characterized in that the mold (34) comprises at least: a lower housing (38), an upper housing (46), a side housing (40), and an end housing (42, 44), and each of the side housing (40) and the end housing (42, 44) comprises three elements, namely a lower element (40a, 42a, 44a), an intermediate element (40b, 42b, 44b), and an upper element (40c, 42c, 44c).

Description

Technical Field

[0001] The present invention relates to an apparatus for forming fiber preforms for producing turbine blade components and a method for using the apparatus. Background Technology

[0002] In particular, the background art includes documents FR-A1-2 940 057, FR-A1-3 014 008, FR-A1-3029134, FR-A1-3 032 147, FR-A1-3 046 404, FR-A1-3 051 348 and WO-A1-2014 / 076 348.

[0003] The use of composite materials is advantageous in the aerospace industry, especially because these materials offer beneficial mechanical properties for relatively low mass.

[0004] The method known to those skilled in the art for manufacturing composite material components for the aerospace industry is the RTM (Resin Transfer Molding) process.

[0005] This method includes a process for producing components made of composite materials based on resin-impregnated fibers. For example, this method is used to manufacture turbine blade components, such as fan blades or rectifier blade cascades.

[0006] The RTM process involves multiple consecutive steps.

[0007] We begin with three-dimensional weaving to obtain a preform blank, which is then cut to obtain a preform with the approximate shape of the blade component to be obtained. The preform is then arranged inside a closed mold.

[0008] In current technology, this mold has two functions or two consecutive uses. First, the mold is used to complete the molding of the preform through thermal compression. Therefore, the mold is pressed and baked to compress and harden the preform.

[0009] The mold is then used to inject resin into the preform for impregnation. The resin is injected through the mold's supply port, and the mold is then baked to cause the resin to polymerize and cure.

[0010] The blade assembly is then removed from the mold and can undergo various continuous operations, particularly finishing.

[0011] Advantageously, a single mold can be used to perform both the molding and resin injection steps. However, a disadvantage of this technique is that the mold cannot be particularly suited to and optimized for either of these steps, as it must also be adapted to perform the other step. The mold combines the constraints of both steps, making it more complex and expensive.

[0012] Furthermore, this mold is not suitable for performing other functions, such as positioning and securing the metal shield to the leading edge of the blade component.

[0013] Composite materials for blade components are relatively fragile and particularly sensitive to impact, and it is known to protect the composite materials of blade components by attaching and fastening a metal shield to the leading edge of the blade component.

[0014] The shield can be fastened to the blade in several ways. The first method involves gluing the shield to the blade assembly after the resin has polymerized.

[0015] A second method of securing the shroud to the blade assembly involves co-molding the shroud with a fiber preform. The preform is arranged in a mold, and the shroud is positioned or even glued to the edge of the preform intended to form the leading edge of the blade. Injected resin impregnates the preform and makes contact with the shroud to ensure the shroud is secured to the blade after the resin polymerizes and cures. An adhesive film can be inserted between the preform and the shroud and then designed to polymerize simultaneously with the resin, which facilitates mating and avoids the need for thermal cycling on the end assembly.

[0016] The aforementioned molds in the current technology are not suitable for positioning the protective cover on the prefabricated part or fixing the protective cover.

[0017] The present invention provides a solution to these problems, the solution comprising providing an apparatus particularly adapted to perform only one of the above functions (i.e., in this case, the forming of a preform), and also adapted to perform the mating of the metal shield with the leading edge of the preform. Summary of the Invention

[0018] The present invention relates to an apparatus for forming at least one fiber preform for producing turbine blade components, the apparatus comprising a mold formed of a plurality of interlocking components defining at least one internal cavity configured to receive and integrally enclose the preform, the cavity being intended to have two plateau regions and a blade region extending between the two plateau regions.

[0019] The mold is characterized in that it comprises at least:

[0020] - Lower housing, which forms the lower end of the mold and includes a convex curved surface of the blade region.

[0021] - An upper housing, which forms the upper end of the mold and includes a concave curved surface of the blade portion, the upper housing and the lower housing being fastened to each other, defining a first side of the mold, and a first groove for forming the trailing edge of the blade region being formed between the upper housing and the lower housing.

[0022] A side housing, forming a second side of the mold, opposite to the first side, and forming a second groove for forming the leading edge of the blade region, and

[0023] - End housings, located at two opposite ends of the mold, with a lower housing, an upper housing, and side housings extending between the end housings, each forming at least a portion of the platform region.

[0024] Furthermore, each of the side housing and the end housing includes three elements: a lower element, a middle element, and an upper element. The elements of the side housing and the end housing are independently and removably fastened to allow for removal and disassembly from the mold without disassembling the upper and lower housings.

[0025] The device is specifically designed and optimized to complete the forming of the preform, which is preferably achieved by compressing and heating the preform in a mold. More advantageously, the device according to the invention is designed to precisely position the metal shield on the leading edge of the preform.

[0026] The different components of the mold facilitate its assembly around the preform and its disassembly, particularly partial disassembly. In fact, the end housing components can be installed and removed independently of the upper and lower housings. The side housing components can also be installed and removed independently, allowing access to the leading edge of the preform for positioning the guard.

[0027] The convex curved surface of the lower casing is configured to complement the concave side of the blade (referred to as the inner curved surface). The concave curved surface of the upper casing is configured to complement the convex side of the blade (referred to as the outer curved surface).

[0028] Furthermore, the implementing apparatus according to the present invention may include one or more of the following features, either individually or in combination:

[0029] -The three components of the side housing include:

[0030] + Lower housing element, which is located below the second recess and includes a first upper sliding surface.

[0031] + An intermediate housing element, located on the lower housing element and defining the lower portion of the second recess, the intermediate housing element including a second lower sliding surface configured to slidably engage with the first surface during disassembly of the intermediate housing element, and

[0032] + Upper housing element, which is located on the intermediate housing element and defines the upper portion of the second groove;

[0033] - The first and second surfaces are inclined at an angle α relative to the horizontal plane, which is greater than the inclination angle β of the lower portion of the second groove, which is also measured relative to the horizontal plane;

[0034] - Each of the lower portion of the second groove and the upper portion of the second groove defines a stepped portion for over-pressing the preform;

[0035] - Each end housing in the end housing comprises three elements:

[0036] + Lower housing element, which, together with the lower housing, defines the lower portion of the corresponding platform area.

[0037] + Upper housing element, which, together with the upper housing, defines the upper portion of the platform region, and

[0038] + Intermediate housing element, which is inserted between the lower housing element and the upper housing element, and is configured to extend in the continuation of the blade region;

[0039] - Each of the end housings has an intermediate housing element that includes a protruding rib configured to engage in an internal channel of the preform.

[0040] - The intermediate housing element includes an indexing member configured to mate with a complementary member of at least one of the lower housing, upper housing, and side housing;

[0041] - The housing and housing elements of the mold are fastened by screws that pass through the holes of these housings or housing elements and screw into the threaded holes of other housings or housing elements;

[0042] - The mold has a general shape of a parallelepiped, and includes recesses on at least some of the surfaces of the mold for reducing mold weight.

[0043] The present invention also relates to a method for forming at least one fiber preform for producing turbine blade components using the forming apparatus described above, characterized in that the method comprises the following steps:

[0044] a) Installing a preform into the cavity of a mold, the preform comprising two platforms and blades extending between the two platforms.

[0045] b) Enclose the forming device to compress the preform.

[0046] c) Bake the forming device to dry the preform, and

[0047] d) Disassemble the mold and remove the preform.

[0048] Advantageously, step a) includes the following sub-steps:

[0049] a1) Install the prefabricated component onto the lower housing of the mold, as well as the lower and intermediate components of the side housing; a2) Install the upper housing components of the upper housing and side housing onto the prefabricated component.

[0050] a3) Install the intermediate housing components of the end housing;

[0051] a4) Install the lower and upper housing components of the end housing.

[0052] The method may include step 0) prior to step a): inserting a mandrel, such as a foam block, into an internal channel of the preform that extends within the blade and opens at the platform.

[0053] The method may include, between substeps a1) and a2), an additional substep y) for installing components at each end of the mandrel (foam block) at the end of the precast component, and between substeps a2) and a3), a substep z) for removing these positioning components.

[0054] The method may include step x) between steps c) and d), which involves mating a metal shield onto the leading edge of the preform, and this step includes the following sub-steps:

[0055] x1) Remove and detach the upper housing components from the side housing.

[0056] x2) Remove and detach the intermediate housing components from the side housing, and

[0057] x3) ​​Position the protective cover on the leading edge of the precast component. Attached Figure Description

[0058] Other features and advantages will become apparent from the following description of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which:

[0059] [ Figure 1 ] Figure 1 This is a schematic perspective view of the turbine blade assembly;

[0060] [ Figure 2 ] Figure 2 This is a schematic perspective view of a forming apparatus according to an embodiment of the present invention;

[0061] [ Figure 3 ] Figure 3 yes Figure 2 Another schematic perspective view of the device;

[0062] [ Figure 4 ] Figure 4 It is based on Figure 2 and Figure 3 A schematic cross-sectional view of line IV-IV, showing the prefabricated component located in the device;

[0063] [ Figure 5 ] Figure 5 It is based on Figure 2 and Figure 3 A schematic partial cross-sectional view of line VV, showing the prefabricated component located in the device;

[0064] [ Figure 6 ] Figure 6 yes Figure 4 A magnified view of a portion;

[0065] [ Figure 7 ] Figure 7 yes Figure 2 A schematic perspective view of the components of the lower housing and side housing of the device mold, in which preforms of blades with integrated platforms are arranged;

[0066] [ Figure 8 ] Figure 8 yes Figure 7 A schematic perspective view of the kit, with the upper housing of the mold attached to the kit;

[0067] [ Figure 9 ] Figure 9 yes Figure 8 A schematic perspective view of the kit, showing the intermediate element of the end housing of the mold attached to the kit;

[0068] [ Figure 10 ] Figure 10 yes Figure 9 A schematic perspective view of the kit, showing the lower element of the end housing of the mold attached to the kit;

[0069] [ Figure 11 ] Figure 11 yes Figure 10 A schematic perspective view of the kit, showing the upper element of the end housing of the mold attached to the kit; furthermore, the upper and middle elements of the side housings have been removed; and

[0070] [ Figure 12 ] Figure 12 This is a flowchart illustrating the steps and sub-steps of a method for forming a preform according to the present invention. Detailed Implementation

[0071] First refer to Figure 1 , Figure 1 A blade component 10 made of composite material for a turbine is shown, which includes, for example, fan blades or, in the case of a twin-ducted turbojet engine, the blade cascade of a secondary flow rectifier.

[0072] The blade component 10 includes a blade 12. In the case that the component 10 is a fan blade, the blade 12 is connected to a root 16 via a shank 14, which has, for example, a dovetail shape and is shaped to fit into a recess of a complementary shape in a rotor disk to hold the blade on the disk.

[0073] In the case where component 10 is replaced by a rectifier cascade, blade 12 extends between two platforms 16a and 16b, which are generally parallel to each other and perpendicular to the extension axis of blade 14.

[0074] The blade 12 includes a leading edge 12a and a trailing edge 12b for the gas flowing in the turbine. The blade 12 has a curved or twisted aerodynamic profile and includes an inner arcuate surface 18 and an outer arcuate surface 20 extending between the leading edge 12a and the trailing edge 12b.

[0075] The blade 12 is made of a fiber preform obtained by three-dimensionally weaving fibers (such as carbon fibers).

[0076] The leading edge 12a of the blade is reinforced and protected by a metal shield 22 fastened to the leading edge 12a. For example, the shield 22 is made of an alloy based on nickel and cobalt.

[0077] In this invention, the correct positioning of the cover 22 on the preform is accomplished by means of means 30 for forming the preform, which is preferably achieved by compression and heating.

[0078] Figures 2 to 11 An embodiment of the device 30 according to the present invention is shown.

[0079] Figure 2 and Figure 3 The device 30 is shown in its entirety. In the example shown, the device has a general shape of a parallelepiped.

[0080] Figure 4 and Figure 5A cross-sectional view of the device 30 is shown, and the device includes at least one internal cavity 32 configured to accommodate the blade component to be produced or the fiber preform of each blade component 10.

[0081] In the example shown, the blade component 10 is a rectifier blade cascade. Thus, it can be noted that the cavity 32 generally comprises three parts or regions: the blade region Z1 and two platform regions Z2, Z3, the blade region being designed to accommodate the portion of the blade 12 forming the preform of the blade component 10, and the two platform regions being designed to accommodate the portions of the platforms 16a, 16b forming the preform of the blade component 10.

[0082] The device 30 generally includes a mold 34. In the example shown, the mold is shown on a flat support or base 36, however this is optional.

[0083] The mold 34 has a general shape of a parallelepiped and includes an upper surface 34a, a lower surface 34b, and four side surfaces 34c-34f. In this case, surfaces 34a-34f are rectangular. The mold 34 is placed flat on the base 36 by supporting the lower surface 34b on the base 36.

[0084] Side surfaces 34e and 34f are located on two opposite sides of mold 34 and at platform regions Z2 and Z3 of cavity 32 (see...). Figure 5 Side surfaces 34c and 34d are located on two opposite sides of mold 34, and are located at the leading edge 12a and trailing edge 12b of blade 12, respectively (see...). Figure 4 ).

[0085] The mold 34 is obtained by assembling multiple components to facilitate the mounting of the mold around the preform, as well as the positioning and clamping of the preform, while also allowing access to the leading edge 12a of the preform for positioning the metal shield 22.

[0086] In this configuration, the components of mold 34 are formed by interlocking housings or housing elements to define cavity 32. As shown, cavity 32 is entirely defined by mold 34, meaning that mold 34 is configured to integrally enclose the preform.

[0087] In the non-limiting example shown, mold 34 generally comprises five shells, namely:

[0088] -Lower housing 38

[0089] - Side shell 40,

[0090] - Two end housings 42, 44, and

[0091] - Upper casing 46.

[0092] Lower housing 38 Figure 4 and Figure 5 As shown in, and in Figure 7 It is mounted on the base 36. The housing 38 forms part of the lower end of the mold 34 and includes a portion of surface 34b and a lower portion of surface 34d.

[0093] The lower housing 38 defines the lower portion of the cavity 32 and includes an upper surface 48 having a convex, curved section (see [reference]). Figure 4 The convex, curved section is intended to be located on the inner arc surface 18 side of the blade 12.

[0094] Figure 5 The surface 48 is shown to connect to end surfaces 50, which are generally parallel to each other and perpendicular to the surface 48, at platform regions Z2 and Z3 of the cavity 32. Therefore, the lower housing 38 defines the lower portion of each of the platform regions Z2 and Z3 of the cavity 32.

[0095] The upper housing 46 forms part of the upper end of the mold 34 and includes a portion of surface 34a and the upper portion of surface 34d.

[0096] The housing 46 defines the upper portion of the cavity 32 and includes a lower surface 52 having a concave, curved section (see [reference]). Figure 4 The concave curved section is intended to be located on the outer arc surface 20 side of the blade 12.

[0097] The upper housing 46 and the lower housing 38 are fastened to each other, for example, by a screw 54 that passes through a hole 56 in the upper housing and is screwed into a threaded hole 58 in the lower housing (see...). Figure 2 , Figure 4 and Figure 7 ).

[0098] The upper housing 46 and the lower housing 38 define a first side of the mold 34, and a first groove 60 for forming the trailing edge 12b of the blade 12 is formed between the upper housing and the lower housing. Figure 4 ).

[0099] The side shell 40 is particularly in Figures 2 to 4 As shown, the second side of the mold 34 is formed, namely the second side including the surface 34c located on the leading edge 12a side of the blade 12. The housing 40 forms a second groove 62 for forming the leading edge 12a of the blade. Figure 4 and Figure 6 ).

[0100] The side housing 40 is fastened to the lower housing 38 and the upper housing 46 by screws 64, which pass through the hole 66 in the side housing 40 and are screwed into the threaded holes 68 in the lower housing 38 and the upper housing 46. Figures 2 to 4 as well as Figure 11 ).

[0101] In particular, such as Figure 4 As shown, the side housing 40 includes three elements: a lower element 40a, a middle element 40b, and an upper element 40c. These three elements are independently and removably fastened to allow them to be removed from the mold 34 without disassembling the upper housing 46 and the lower housing 38.

[0102] The three components of the side housing 40 include:

[0103] + Lower housing element 40a, which is located below the second recess 62 and includes a first upper sliding surface 70.

[0104] + intermediate housing element 40b, which is located on the lower housing element 40a and defines the lower portion of the second recess 62 ( Figure 6 Reference numeral 62a) in the accompanying drawings indicates that the intermediate housing element includes a second lower sliding surface 72, which is configured to slidably engage with the first sliding surface 70 during disassembly of the intermediate housing element 40b.

[0105] + Upper housing element 40c, which is located on the intermediate housing element 40b and defines the upper portion of the second recess 62 ( Figure 6 (Ref. 62b in the accompanying drawings). The housing element 40c includes a vertical or nearly vertical surface 73a, which is configured to slidably engage with the complementary surface 73b of the upper housing 46 during disassembly of the upper housing element 40c. Figure 4 ).

[0106] like Figure 4 and Figure 6 As shown, the first surface 70 and the second surface 72 are inclined at an angle α relative to the horizontal plane. This angle α is greater than the inclination angle β of the lower portion 62a of the second groove 62, which is also measured relative to the horizontal plane.

[0107] Figure 6 This is an enlarged view of the second groove 62, showing that each of the lower portion 62a and the upper portion 62b of the second groove 62 defines a step 74 for over-pressuring the preform. The step 74 allows the intended position of the shield to be defined so that the shield can better mate with the preform.

[0108] End housings 42 and 44 are designed to define the platform regions Z2 and Z3 of cavity 32 with the lower housing 38 and the upper housing 46. Figure 5 ).

[0109] lie in Figure 3 The first end housing 42 on the left side includes a surface 34e and is formed by assembling three elements 42a, 42b, and 42c. Located in Figure 3 The second end housing 44 on the right side includes a surface 34f and is formed by assembling three elements 44a, 44b, and 44c.

[0110] The three elements of each of the end housings 42 and 44 include ( Figure 5 ):

[0111] + Lower housing elements 42a and 44a, which, together with the lower housing 38, define the lower portions of the corresponding platform regions Z2 and Z3.

[0112] + Upper housing elements 42c and 44c, which, together with the upper housing 38, define the upper portions of the platform regions Z2 and Z3, and

[0113] + Intermediate housing elements 42b, 44b, which are inserted between lower housing elements 42a, 44a and upper housing elements 42c, 44c, and are configured to extend in the continuation of the blade region Z1.

[0114] The intermediate housing element 42b, 44b of each of the end housings 42, 44 includes a protruding rib 76 configured to engage in an internal channel 78 of the preform.

[0115] like Figure 2 and Figure 3 As shown, the intermediate housing elements 42b and 44b may include an indexing member 80a configured to mate with a complementary member 80b of at least one of the lower housing 38, the upper housing 46, and the side housing 40. For example, the indexing members 80a and the complementary members 80b mate by a convex-concave nesting or fitting, and the indexing members and complementary members include, for example, fingers carried by the housing elements 42b and 44b and recesses formed on the lower housing 38.

[0116] Each intermediate housing element 42b, 44b includes an upper end and a lower end, which are shaped to fit into corresponding ends of upper housing elements 42c, 44c and lower housing elements 42a, 44a, respectively. These ends may also be shaped to ensure secure installation and prevent installation of one element instead of the other.

[0117] The housing elements of each end housing 42, 44 are fastened by screws 82 that pass through the holes 84 of these housing elements and are screwed into the threaded holes 86 of other housings or housing elements.

[0118] These figures show that at least some surfaces 34a, 34c of the mold 34 have recesses 88 for reducing mold weight. In the example shown, the upper housing 46 includes recesses 88 on the upper surface 34a (see Figure 1). Figure 2 and Figure 3 The side housing 40 includes an upper housing element 40c with a recess 88 on its side surface 34c, and a lower housing 38 with a recess 88 on its lower surface 34b (see [link]). Figure 4 This is especially true in this situation.

[0119] The present invention also relates to a method for forming a preform using a device 30 to produce turbine blade components.

[0120] The method will now be described with reference to the accompanying drawings, and through... Figure 12 The flowchart is used to illustrate this.

[0121] This method generally includes four steps, namely the following steps:

[0122] a) The preform is installed in the cavity 32 of the mold 34. The preform includes two platforms 16a and 16b and a blade 12 extending between the two platforms.

[0123] b) Seal the device 30 to compress the precast components.

[0124] c) Bake the device 30 to dry the preform, and

[0125] d) Disassemble mold 34 and remove preforms.

[0126] The method may include step 0) before or during step a): inserting a mandrel (e.g., foam block 90) into an internal channel 78 of the preform, which extends inside the blade and opens at platforms 16a, 16b.

[0127] In practice, during the formation of preforms by three-dimensional weaving of yarns (such as carbon yarns), debonding occurs at the center of the blade and along its entire longitudinal dimension to form... Figure 4 The channel 78 is shown in the cross-section. (See example...) Figure 5 As shown, the channel 78 extends through the entire length of the blade 12 to open at platforms 16a and 16b. The mandrel (foam block 90) is inserted into the channel 78 and must be correctly positioned inside the channel 78.

[0128] Step a) of the method is particularly in Figures 7 to 10 As shown in the image.

[0129] Advantageously, step a) includes the following sub-steps:

[0130] a1) The preform is installed on the lower housing 38 of the mold 34 and on the lower element 40a and intermediate element 40b of the side housing 40 (see...). Figure 7 Then, the blade 12 of the prefabricated part is positioned on the surface 48 of the lower housing 38, and the leading edge 12a of the blade is positioned on the lower portion 62a of the groove 62 (see...). Figure 6 The platform is then partially applied to the surface 50 of the lower housing 38. Figure 5 This positioning can be precisely accomplished by projecting a laser beam onto the preform and mold and aligning the tracer (e.g., glass fiber) or marker on the preform and mold 40 with the projection.

[0131] a2) The upper housing 46 is mounted on the prefabricated part and the lower housing 38, and the upper housing element 40c of the side housing 40 is mounted on the intermediate housing element 40b (see Figure 8 ),

[0132] a3) Install the intermediate housing elements 42b and 44b of the end housings 42 and 44; this allows the aforementioned rib 76 to engage in the end of the blade channel 78 and to be supported on the end of the mandrel (foam block 90) to properly position the rib in the channel; this also ensures the perfect formation of the radial portion of the preform blade without bending during compression and drying; in fact, the radial portion is a critical area of ​​the component, and bending will lead to a significant reduction in mechanical properties; the proper positioning by indexing the housing elements 42b and 44b is ensured by the cooperation of the aforementioned components 80a and 80b.

[0133] a4) Install the lower housing elements 42a, 44a and the upper housing elements 42c, 44c of the end housings 42, 44 (see Figure 10 Then see Figure 2 and Figure 3 ).

[0134] The method may include, between sub-steps a1) and a2), an additional sub-step y) for installing components 92 at each end of the precast mandrel (foam block 90) at each end. One of these components 92 is... Figure 7As shown, it can be mounted on the base 36. These components 92 are used to hold the mandrel (foam block 90) in place before the upper housing 46 is installed and fastened. After the upper housing 46 is fastened, the blade 12 is fixedly held between the lower housing 38 and the upper housing 46, and the mandrel (foam block 90) can no longer move within the channel 78. Then the components 92 are no longer needed, and the method subsequently includes a sub-step z) between sub-steps a2) and a3) to remove these positioning components.

[0135] In step b), the device 30 is closed to clamp the housings of the mold 34 together and to compress the preform. In step c), the kit is baked to dry the preform and to fix its predetermined shape by shaping and compressing the preform.

[0136] The method may also include step x) between steps c) and d), where the metal shield 22 is mated onto the leading edge 12a of the preform. This step x) is... Figure 4 and Figure 11 As shown in the figure, it includes the following sub-steps:

[0137] x1) Remove and detach the upper housing element 40c from the side housing 40; this displacement is schematically shown by arrow 1 and proceeds from bottom to top; during this displacement, surfaces 73a and 73b can slide against each other; this sub-step x1) allows the leading edge 12a to be released on the outer arcuate side of the blade.

[0138] x2) Remove and disassemble the intermediate housing element 40b from the side housing 40; this displacement is schematically shown by arrow 2 and is carried out in a direction parallel to surfaces 70, 72, as these surfaces serve as guides; angle α is greater than angle β, allowing housing element 40b to be removed without any risk of contact with the leading edge and preform and deformation of the leading edge and preform; this sub-step x2) allows the leading edge 12a to be released on the inner side of the blade; thus the leading edge 12a is completely free, and

[0139] x3) ​​Position the protective cover 22 on the leading edge 12a of the preform.

[0140] The positioning of the shield 22 can then be accomplished by laser-projecting the contour of the shield onto the preform. This has the advantage of positioning the shield within the reference frame of the device 30, thus ensuring correct positioning compared to cases where it has already been positioned relative to the preform (e.g., relative to the tracer). During this operation, the preform (which has been wedged into the mold reference frame) is held in place by the rest of the mold and cannot be moved.

[0141] The aforementioned reference Figure 6The aforementioned over-compression facilitates the mounting of the shield 22 onto the leading edge 12a. This over-compression can be defined as such that the additional reduction in thickness resulting from crushing compensates for the thickness of the shield 22, the elastic return of the preform (during disassembly of the housing), the possible thickness of the adhesive film, and sufficient clearance to allow insertion of the shield. In the case where the shield 22 is secured to the leading edge 12a with adhesive, this reduction in thickness can also compensate for the thickness of the adhesive film or for variations in the film's thickness.

[0142] In step x), the blade 12 and the leading edge 12a may have a generally horizontal orientation, as shown. Alternatively, the blade 12 and the leading edge may be oriented substantially vertically to facilitate mounting the shroud 22 onto the leading edge.

[0143] In the next step, the dried and hardened preform can be transferred to another mold for injecting resin into the preform and hardening the blade component 10.

[0144] The device according to the invention is advantageous in some respects because it is suitable and optimized for preform forming and shroud mating. For example, compared to resin injection molds, the device does not necessarily include sealing components (e.g., gaskets). Furthermore, the device can be made of lightweight or highly thermally conductive materials (e.g., aluminum) (to optimize heating cycles) to facilitate handling of the device.

[0145] Although not shown, the device according to the invention can be used to manufacture multiple blade components simultaneously and can include cavities for accommodating multiple preforms or multiple different cavities for accommodating these preforms.

Claims

1. A forming apparatus (30) for forming at least one fiber preform for producing a turbine blade component (10), the forming apparatus comprising a mold (34) formed by a plurality of interlocking components defining at least one internal cavity (32) configured to receive and integrally enclose the fiber preform, the internal cavity (32) being intended to have two platform regions (Z2, Z3) and a blade region (Z1) extending between the two platform regions. Its features are, The mold (34) includes at least: - Lower housing (38), which forms the lower end of the mold (34) and includes the convex curved surface (48) of the blade region (Z1). - Upper housing (46), which forms the upper end of the mold (34) and includes a concave curved surface (52) of the blade region (Z1), the upper housing (46) and the lower housing (38) are fastened to each other, the upper housing and the lower housing define a first side of the mold, and a first groove (60) is formed between the upper housing and the lower housing for forming the trailing edge (12b) of the blade region (Z1). - A side housing (40) forming a second side of the mold (34), the second side being opposite to the first side, and forming a second groove (62) for forming the leading edge (12a) of the blade region (Z1), and - End housings (42, 44), said end housings being located at two opposite ends of the mold, said lower housing (38), said upper housing (46) and said side housings (40) extending between said end housings, said end housings forming at least a portion of said platform regions (Z2, Z3), Furthermore, each of the side housing (40) and the end housings (42, 44) includes three housing elements: a lower housing element (40a, 42a, 44a), an intermediate housing element (40b, 42b, 44b), and an upper housing element (40c, 42c, 44c). The three housing elements of the side housing (40) and the end housings (42, 44) are independently and removably fastened to allow for removal from the mold without disassembling the upper housing (46) and the lower housing (38).

2. The forming apparatus (30) according to claim 1, wherein, The three housing elements of the side housing (40) include: - The lower housing element (40a) of the side housing (40), the lower housing element of the side housing (40) is located below the second groove (62) and includes a first upper sliding surface (70). - The intermediate housing element (40b) of the side housing (40), the intermediate housing element of the side housing (40) being located on the lower housing element (40a) of the side housing (40) and defining the lower portion (62a) of the second groove (62), the intermediate housing element (40b) of the side housing (40) including a second lower sliding surface (72), the second lower sliding surface being configured to slidably engage with the first upper sliding surface (70) when the intermediate housing element (40b) of the side housing (40) is disassembled, and - The upper housing element (40c) of the side housing (40) is located on the middle housing element (40b) of the side housing (40) and defines the upper portion (62b) of the second groove (62).

3. The forming apparatus (30) according to claim 2, wherein, The first upper sliding surface (70) and the second lower sliding surface (72) are inclined at an angle α relative to the horizontal plane, which is greater than the inclination angle β of the lower portion (62a) of the second groove (62), and the inclination angle is also measured relative to the horizontal plane.

4. The forming apparatus (30) according to claim 2 or 3, wherein, Each of the lower portion (62a) and the upper portion (62b) of the second groove (62) defines a stepped portion (74) for over-compressing the fiber preform.

5. The forming apparatus (30) according to any one of claims 1 to 3, wherein, The three housing elements of each of the end housings (42, 44) include: - The lower housing element (42a, 44a) of each of the end housings (42, 44), the lower housing element of each of the end housings (42, 44) and the lower housing (38) define the lower portion of the corresponding platform region (Z2, Z3), - The upper housing element (42c, 44c) of each of the end housings (42, 44), the upper housing element of each of the end housings (42, 44) and the upper housing (46) define the upper portion of the platform region (Z2, Z3), and - An intermediate housing element (42b, 44b) of each end housing (42, 44) is inserted between the lower housing element (42a, 44a) and the upper housing element (42c, 44c) of each end housing (42, 44) and is configured to extend in the continuation of the blade region (Z1).

6. The forming apparatus (30) according to any one of claims 1 to 3, wherein, The intermediate housing element (42b, 44b) of each of the end housings (42, 44) includes a protruding rib (76) configured to engage in the internal channel (78) of the fiber preform.

7. The forming apparatus (30) according to any one of claims 1 to 3, wherein, The intermediate housing element (42b, 44b) of each of the end housings (42, 44) includes an indexing member (80a) configured to cooperate with a complementary member (80b) of at least one of the lower housing (38), the upper housing (46) and the side housing (40).

8. The forming apparatus (30) according to any one of claims 1 to 3, wherein, The housing and housing elements of the mold (34) are fastened by screws (54, 64, 82) that pass through the holes (56, 66, 84) of these housings or housing elements and are screwed into the threaded holes (58, 68, 86) of other housings or housing elements.

9. The forming apparatus (30) according to any one of claims 1 to 3, wherein, The mold (34) has a parallelepiped shape and includes recesses (88) on at least some of the surfaces of the mold for lightening the mold.

10. A method for forming at least one fiber preform of a turbine blade component (10) by means of a forming apparatus (30) according to any one of claims 1 to 9, characterized in that, The method includes the following steps: a) Install the fiber preform in the internal cavity (32) of the mold (34), the fiber preform comprising two platforms (16a, 16b) and a blade (12) extending between the two platforms. b) The forming device (30) is closed to compress the fiber preform. c) The forming device (30) is baked to dry the fiber preform, and d) Disassemble the mold (34) and remove the fiber preform.

11. The method according to claim 10, wherein, Step a) includes the following sub-steps: a1) The fiber preform is installed on the lower housing (38) of the mold (34) and on the lower housing element (40a) and the middle housing element (40b) of the side housing (40). a2) The upper housing element (40c) of the upper housing (46) and the side housing (40) is mounted on the fiber preform. a3) Install the intermediate housing elements (42b, 44b) of the end housings (42, 44); a4) Install the lower housing element (42a, 44a) and the upper housing element (42c, 44c) of the end housing (42, 44).

12. The method according to claim 11, wherein, The method includes step 0) prior to step a): inserting a mandrel into an internal channel (78) of the fiber preform, the internal channel extending within the blade (12) and opening at the platform (16a, 16b).

13. The method according to claim 12, wherein, The method includes, between substeps a1) and a2), an additional substep y) for installing positioning members (92) for positioning the mandrel at each end of the fiber preform, and between substeps a2) and a3), a substep z for removing these positioning members (92).

14. The method according to any one of claims 10 to 13, wherein, The method includes step x) between steps c) and d), which involves mating a metal shield (22) onto the leading edge (12a) of the fiber preform. This step includes the following sub-steps: x1) Remove and detach the upper housing element (40c) from the side housing (40). x2) Remove the intermediate housing element (40b) from the side housing (40) and remove it from the side housing (40). x3) ​​Position the metal shield (22) on the leading edge (12a) of the fiber preform.

15. The method according to claim 12, wherein, The mandrel is a foam block (90).

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