COMPOSITE PART WITH A CO-INJECTED MARKING ELEMENT

Abstract

The present invention relates essentially to a method for manufacturing a composite part (7) comprising: - a step of weaving a fibrous preform (9), - a step of positioning the fibrous preform (9) inside a mold (33), - a step of positioning a marking element (26) on the fibrous preform (9), said marking element (26) being intended to identify the composite part (7), and - a step of injecting a resin (10), such that the fibrous preform (9) and the marking element (26) are covered by the resin (10). Figure 4c

Description

Title of the invention: COMPOSITE PART WITH A CO-INJECTED MARKING ELEMENT

[0001] The present invention relates to a composite part equipped with a co-injected marking element. The invention finds a particularly advantageous, but not exclusive, application in fan blade shims. The invention can also be implemented with a ferrule sector or engine kit fairing or any other turbomachine part made of a composite material and, more generally, any other part made of a composite material in any type of industry.

[0002] In a turbojet engine, the blades, consisting of a root and a blade defined by two sides called the lower and upper surfaces respectively, are mounted in groove-shaped recesses, called cells, arranged around the periphery of a rotor disk. The blades are mounted with a clearance between their root and the walls of the cells. For the proper operation of the turbojet engine, the blade roots and the disk cells must be in contact throughout the engine's rotational range. The contact surfaces between the blade roots and the cells are called bearing surfaces.

[0003] Shims inserted into the recesses under each blade foot compensate for any play between the bottom of the recesses and the end of the blade feet, ensuring correct positioning of the blade feet on the disc bearing surfaces. The shims also accommodate the movement of the blade feet in the event of blade loss or ingestion of a foreign object.

[0004] The wedges can be made of a composite material comprising a fibrous reinforcement structure, known as a fibrous preform. The fibrous preform is obtained by 3D weaving using a Jacquard-type loom, as described in documents WO2013 / 088037 and FR3062659.

[0005] The fibrous preform is then placed in a mold into which a resin is injected. After polymerization of the resin, a rough composite part is obtained, which is then machined to produce a finished part. Machining may consist of a step of cutting the contours of the part, notably by water jet, laser, or plasma cutting.

[0006] The wedge is a serialized part that must be traceable. This need for traceability is reflected in the application of a marking label to the part, including a serial number.

[0007] Generally, the part is marked twice during the manufacturing cycle, namely once during the production of the raw part and a second time in the final stage on the finished part. This double marking is carried out manually by a The operator is costly in terms of both labor and materials required to produce the labels. Furthermore, the operator may sometimes apply the marking label incorrectly, leading to rework or even the rejection of the part. Double marking therefore increases the risk of rework and rejection.

[0008] The invention aims to effectively remedy these drawbacks by proposing a method for manufacturing a composite part comprising: - a step in weaving a fibrous preform, - a step of positioning the fibrous preform inside a mold, - a step of positioning a marking element on the fibrous preform, said marking element being intended to identify the composite part, and - a resin injection step, so that the fibrous preform and the marking element are covered by the resin.

[0009] The invention thus makes it possible, by embedding the fibrous preform and the marking label within the resin, to eliminate the step of applying a marking label to the finished part. This results in a saving in manufacturing time, a saving in material cost (that of the additional label), as well as a reduction in the risk of rejection of the final part.

[0010] According to one embodiment of the invention, said method further comprises: - a resin polymerization step to obtain a raw composite part, and - a machining step of the raw composite part to obtain a finished composite part.

[0011] According to one embodiment of the invention, the raw composite part comprises an unmachined area and at least one machined area intended to be machined during the machining step, the marking element being arranged on the fibrous preform so as to be subsequently located in an unmachined area of ​​the raw composite part.

[0012] According to one embodiment of the invention, said method further comprises a step of placing a template on the fibrous preform, said template comprising a window delimiting at least a part of the unmachined area of ​​the raw composite part and a step of positioning the marking element inside the window of the template.

[0013] According to one embodiment of the invention, the marking element is a marking label.

[0014] According to one embodiment of the invention, the composite part is a blower blade wedge.

[0015] The invention also relates to a composite part comprising a fibrous preform, a resin, and a marking element intended to identify the composite part, in which the resin covers the fibrous preform and the marking element.

[0016] According to one embodiment of the invention, the marking element is disposed in an unmachined area of ​​the composite part.

[0017] According to one embodiment of the invention, the composite part is a blower blade wedge.

[0018] According to one embodiment of the invention, the marking element is arranged between two lines extending along a longitudinal direction of the wedge, each line passing through the bottom of at least one hollow made in a longitudinal edge of the blower blade wedge.

[0019] The present invention will be better understood and other features and advantages will become apparent upon reading the following detailed description, which includes embodiments given by way of illustration with reference to the accompanying figures, presented by way of non-limiting examples, which may serve to complete the understanding of the present invention and the explanation of its implementation and, where appropriate, contribute to its definition, on which:

[0020] [Fig. 1a][Fig. 1b] Figures 1a and 1b are perspective views of a wedge according to the invention disposed in a disc cavity under a blade foot respectively with and without blade lock;

[0021] [Fig.2] Fig.2 is a perspective view of a blower blade wedge according to the present invention;

[0022] [Fig. 3] [Fig. 3] is a perspective view of a rough blade block obtained at the outlet of a mold for manufacturing a composite part superimposed with a finished blade shim obtained after machining the raw blade shim;

[0023] [Fig.4a][Fig.4b][Fig.4c][Fig.4d] Figures 4a to 4d schematically illustrate the different stages of a manufacturing process for a blower blade wedge according to the present invention.

[0024] In the figures, it should be noted that the structural and / or functional elements common to the different embodiments may have the same reference numerals. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

[0025] Figure 1a shows a disk 1 of a rotor, for example a blower rotor, around the periphery of which are arranged cavities 2. These cavities 2 may be straight, curved, or of any other shape. In the example given here, the cavities are straight and have a dovetail cross-section.

[0026] A blade 3, comprising a foot 4 and an aerodynamic blade 5, is housed in each cavity 2. The blade foot 4, here dovetail-shaped, is inserted axially into the corresponding cavity 2. A shim 7, shown in more detail in [Fig. 2], is inserted between the foot 4 of the blade 3 and the bottom 6 of the cavity 2. The shim 7, inserted into the cavity 2 under the blade foot 4, compensates for the play between the bottom of the cavity 2 and the end of the blade foot 4 to ensure the correct positioning of the blade foot 4 on the bearing surface of the disk 1.

[0027] The wedge 7 shown in [Fig. 2] is made of a composite material. The wedge 7 comprises a fibrous preform 9 covered by a resin 10. The wedge 7 has an axis X extending along a longitudinal extension direction of the wedge 7. The wedge 7 has a curved shape. The wedge 7 has a concave face 11 and a convex face 12. The wedge 7 also has two longitudinal edges 13 and two end edges 14. The end edges 14 connect the longitudinal edges 13. The longitudinal edges 13 have protruding portions 17 and recesses 18. A recess 18 is located between two consecutive protruding portions 17. The wedge 7 may also include lightening holes 20. The hollows 18 as well as the lightening holes 20 are made to obtain a good compromise between the mechanical strength and the mass of the wedge 7.

[0028] A tab 21, called a wedge head, extends from an end edge 14 of the wedge 7. The wedge head 21 is designed to bear against a blade lock 22 to ensure radial retention of the lock 22, as shown in [Fig. 1b]. The lock 22 is positioned inside grooves 23 formed in the disc 1 so as to ensure axial retention of the blade 3.

[0029] The shim 7 includes a marking element 26 embedded in the resin 10. The marking element 26 contains information relating to the identification of the shim 7, such as a unique serial number associated with the composite part (here, the shim 7) and a number relating to the model of the composite part (here, the shim 7). The marking element 26 advantageously takes the form of a marking label, for example, made of a textile material compatible with the resin used, preferably cotton. Alternatively, the marking element 26 can take the form of a radio frequency chip, such as an RFID chip, or any other marking element 26 suitable for the application. The marking element 26 is located on the concave face 11 of the shim 7. As described in more detail below, the marking element 26 is located in an unmachined area 27 of the shim 7.

[0030] A method for manufacturing a composite part, such as the wedge 7, is described below with reference to Figures 4a to 4c. This method comprises a step of weaving a fibrous preform 9 according to a standard weaving technique known to those skilled in the art. The fibrous preform 9 may comprise carbon fibers, glass fibers, Kevlar fibers, or a mixture of these fibers, or any other type of fiber suitable for the application.

[0031] The fibrous preform 9 is then placed inside a mold 33, as illustrated in [Fig.4a].

[0032] A marking element 26 is positioned on the fibrous preform 9 as illustrated in [Fig.4b].

[0033] The mold 33 is closed. A resin 10 is injected into the mold 33, so that the The fibrous preform 9 and the marking element 26 are covered by the resin 10, as illustrated in [Fig. 4c]. The resin 10 can be a thermoplastic resin or a thermosetting resin.

[0034] The process also includes a step of polymerizing the resin 10 to obtain a raw composite part 7'. For this purpose, the assembly can be placed in an autoclave to undergo a polymerization cycle.

[0035] The raw composite part 7' is then machined to obtain a finished composite part 7. The machining may consist of a step of cutting the contours of the part to create in particular the hollows 18 and the protruding portions 17 made in the longitudinal edges 13. The cutting step also makes it possible to create the lightening holes 20. The cutting step may be carried out in particular by water jet, laser, or plasma cutting.

[0036] As can be seen in [Fig. 3], the raw composite part 7' has at least one unmachined area 27 and at least one machined area 28 intended to be machined during the machining step to obtain the finished part 7 shown superimposed on the raw part 7'. The marking element 26 is arranged on the fibrous preform 9 so as to be subsequently located in the unmachined area 27 of the raw composite part 7'.

[0037] To facilitate the operator's identification of the unmachined area 27, a template 30 can be placed on the fibrous preform 9, as shown in [Fig. 5]. The template 30 has a window 31 delimiting at least part of the unmachined area 27 of the raw composite part 7'. To this end, the template 30 includes indexing means 32 to correctly position the template 30 relative to the fibrous preform 9. The indexing means 32 may, for example, consist of edges cooperating with corresponding edges of the fibrous preform 9. The operator or a robot can then position the marking element 26 inside the window 31 of the template 30. Once the marking element 26 is positioned on the fibrous preform 9 in the desired unmachined area 27, the template 30 is removed from the fibrous preform 9 before the resin injection phase 10.

[0038] As illustrated in [Fig. 2], on the finished wedge 7, the marking element 26 is located between two lines L1, L2 extending along a longitudinal direction of the finished blade wedge 7. Each line passes through the bottom of at least one recess 18 formed in a longitudinal edge of the wedge 7.

[0039] Of course, the different features, variants and / or embodiments of the present invention can be combined with each other in various ways insofar as they are not incompatible or mutually exclusive.

[0040] Furthermore, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, forms alternatives and other variants that a person skilled in the art may consider within the framework of the present invention and in particular all combinations of the different modes of operation described above, which may be taken separately or in association.

Claims

Demands

1. A method for manufacturing a composite part (7) comprising: - a step of weaving a fibrous preform (9), - a step of positioning the fibrous preform (9) inside a mold (33), - a step of positioning a marking element (26) on the fibrous preform (9), said marking element (26) being intended to identify the composite part (7), and - a step of injecting a resin (10), such that the fibrous preform (9) and the marking element (26) are covered by the resin (10), - a step of polymerizing the resin (10) to obtain a rough composite part (7'), and - a step of machining the rough composite part (7') to obtain a finished composite part (7), - the rough composite part (7') comprising at least one unmachined area (27) and at least one machined area (28) intended to be machined during the step machining,the marking element (26) being disposed on the fibrous preform (9) so as to be subsequently located in an unmachined area (27) of the raw composite part (7'), characterized in that said method comprises a step of placing a template (30) on the fibrous preform (9), said template (30) comprising a window (31) delimiting at least a part of the unmachined area (27) of the raw composite part (7') and a step of positioning the marking element (26) inside the window (31) of the template (30).

2. Method according to claim 1, characterized in that the marking element (26) is a marking label.

3. Method according to claim 1 or 2, characterized in that the composite part (7) is a blower blade wedge.

4. Composite part (7) obtained by the process defined according to any one of the preceding claims comprising a fibrous preform (9), a resin (10), and a marking element (26) for identifying the composite part (7), characterized in that the resin (10) covers the fibrous preform (9) and the marking element (26).

5. Composite part according to claim 4, characterized in that the marking element (26) is disposed in an unmachined area (27) of the

6. composite part (7). Composite part according to claim 4 or 5, characterized in that the

7. Composite part (7) is a blower blade wedge. Composite part according to claim 6, characterized in that the marking element (26) is disposed between two lines (L1, L2) extending along a longitudinal direction of the wedge (7), each line (L1, L2) passing through the bottom of at least one hollow (18) made in a longitudinal edge of the blower blade wedge (7).

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