Tool for shaping a fiber texture with magnetic keys

Abstract

Tool for shaping a fibrous texture with magnetic keys Conforming tool (200) for shaping a fibrous texture (230) comprising at least one mold (210) and a counter-mold (220) defining between them a molding cavity, the fibrous texture being intended to be placed in the molding cavity, characterized in that it comprises at least one first magnet (240) present on the mold opposite the counter-mold and in that the counter-mold is configured to position itself and lock with the mold by magnetization with the first magnet. Figure for the abstract: Fig. 2

Description

Title of the invention: Tool for conforming a fibrous texture with magnetic keys Technical field

[0001] The present invention relates to the general field of manufacturing parts made of ceramic matrix composite (CMC) or organic matrix composite (OMC) material, and more particularly to a fibrous texture shaping tool. Prior art

[0002] Organic matrix composite (OMC) or ceramic matrix composite (CMC) materials replace metal parts in certain parts of turbomachines.

[0003] Furthermore, their use contributes to optimizing aircraft performance, in particular by improving the efficiency of the turbomachine and reducing the overall mass of the turbomachine, significantly reducing emissions harmful to the environment (such as CO, CO2, NOx, etc.).

[0004] To be used in civil applications, CMO and CMC composite materials must exhibit stability of their properties over very long periods (30,000 to 100,000 hours), with permissible stresses of an acceptable level (120 to 150 MPa). To meet this specification, CMC and CMO materials are designed to have stable mechanical characteristics at high temperatures.

[0005] Parts made from CMC or CMO material are thus produced from a woven fibrous texture which is shaped (or molded) before being pre-densified, then densified to form its organic or ceramic matrix.

[0006] Currently, the fibrous textures, previously cut, are shaped by hand using a shaping tool or former 100, an example of which is shown in [Fig.l]. This tool 100 makes it possible to give the shape to the part during the unfolding of the original fibrous texture 130.

[0007] This tool 100 has several blocks or sectors, formed here by a mold 110 and a counter-mold 120, which must be installed as the textile is shaped. The tool also has mechanical closing systems 140, 150 for these blocks. Each closing system 140, 150 comprises a screw 142 passing through an orifice formed in the counter-mold 120 and screwing into the mold 110. A washer 141 may be provided between each screw 142 and the counter-mold 120.

[0008] An operator closes the tool using a torque wrench to maintain a tightening torque. On complex conformers, there may be several dozen of closing systems to close to assemble all the sectors of the conformer. The time spent by the operator each time closing and opening the conformer can therefore be quite significant.

[0009] These closing and opening times do not allow high production rates to be achieved, in the order of several tens or hundreds of thousands of pieces per year.

[0010] It is therefore desirable to have a new shaping tool or conformer with reduced assembly time. Statement of the invention

[0011] The invention relates to a shaping tool for shaping a fibrous texture comprising at least one mold and a counter-mold defining between them a molding cavity, the fibrous texture being intended to be placed in the molding cavity, characterized in that it comprises at least one first magnet present on the mold opposite the counter-mold and in that the counter-mold is configured to position itself and lock with the mold by magnetization with the first magnet.

[0012] The shaping tool according to the invention no longer has screw systems and the magnet allows it to be closed and the mold and the counter-mold to be locked together to assemble the shaping tool. This avoids an operator having to close the tool with a certain tightening torque because this can be done automatically with the magnet. It is thus possible to reduce the closing and opening time of the shaping tool, which also reduces the overall time for shaping the fiber textures.

[0013] According to a particular characteristic of the invention, the counter-mold is made of ferromagnetic material. The first magnet can then be sufficient to exert an attractive force on the counter-mold and ensure its positioning and locking.

[0014] Preferably, the first magnet is then positioned centrally on the mold, so as to exert a force centered on the counter-mold and therefore to apply a homogeneous pressure on the fibrous texture.

[0015] According to another particular characteristic of the invention, the shaping tool comprises at least one second magnet present on the counter-mold opposite the first magnet and configured to magnetize with the first magnet. The counter-mold is then not necessarily made of ferromagnetic material.

[0016] According to another particular characteristic of the invention, the first and second magnets are placed centrally on the mold and the counter-mold. They can also be placed centrally relative to the cavity. Such a configuration makes it possible to exert a force centered on the mold and the counter-mold.

[0017] According to another particular characteristic of the invention, the shaping tool comprises at least two pairs of magnets, present on the periphery of the mold and the counter-mold so as to be outside the molding cavity, within each pair of magnets, a first magnet being placed on the mold opposite a second magnet placed on the counter-mold.

[0018] The shaping tool may in particular comprise three or four pairs of magnets.

[0019] Preferably, the pairs of magnets are distributed homogeneously around the periphery of the mold and the counter-mold.

[0020] According to another particular characteristic of the invention, the shaping tool comprises a means for centering the counter-mold on the mold.

[0021] This ensures that the tool is correctly assembled, i.e. that the mold and the counter-mold are correctly positioned relative to each other so that the shape given to the fiber texture corresponds to the intended shape.

[0022] The centering means is preferably placed on the periphery of the mold and the counter-mold.

[0023] According to another particular characteristic of the invention, the centering means comprises at least one pair of magnets placed opposite each other on the mold and the counter-mold.

[0024] This makes it possible to limit the mass of the shaping tool by using a pair of magnets both as a centering means and as a means of locking the mold with the counter-mold.

[0025] According to another particular characteristic of the invention, the centering means comprises a lug placed on the mold or the counter-mold, and a corresponding hole formed in the counter-mold or the mold, respectively.

[0026] According to another particular characteristic of the invention, the magnets are permanent magnets.

[0027] According to another particular characteristic of the invention, each first magnet is an electromagnet.

[0028] Each second magnet can be a permanent magnet or an electromagnet.

[0029] According to another particular characteristic of the invention, the shaping tool comprises a means for activating the electromagnets configured to be able to circulate an electric current through each of said electromagnets. Brief description of the drawings

[0030] Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate exemplary embodiments thereof which are not limiting in nature.

[0031] [Fig-1] [Fig.l] schematically represents a conformation tool of a fibrous texture according to the prior art.

[0032] [Fig.2] [Fig.2] represents, in a schematic and partial manner, a tool of conformation of a fibrous texture according to a first embodiment of the invention.

[0033] [Fig.3] [Fig.3] represents, in a schematic and partial manner, a tool of conformation of a fibrous texture according to a second embodiment of the invention.

[0034] [Fig.4] [Fig.4] represents, in a schematic and partial manner, a tool of conformation of a fibrous texture according to a third embodiment of the invention. Description of the embodiments

[0035] [Fig.2] schematically and partially represents a shaping tool 200 according to a first embodiment of the invention.

[0036] The shaping tool 200 comprises at least one mold 210 and a counter-mold 220. The mold 210 comprises a first shaping surface 210A and the counter-mold 220 comprises a second shaping surface 220A. When the mold 210 and the counter-mold 220 are positioned relative to each other in an operational configuration, a space left free between the first shaping surface 210A and the second shaping surface 220A defines a molding cavity in which a fibrous texture 230 is intended to be placed to be shaped.

[0037] The shaping tool 200 comprises a magnet 240 placed on the mold 210 at the molding cavity, opposite the counter-mold 220. The fibrous texture 230 is intended to be placed above the magnet 240. The counter-mold 220 is, for example, made of magnetic or ferromagnetic material and can thus be positioned and locked on the mold 210 by magnetization thanks to the magnet 240. According to another example, the counter-mold 220 comprises a ferromagnetic core embedded in a non-ferromagnetic metal block, the ferromagnetic core being intended to magnetize with the magnet 240 to position and lock the counter-mold 220 on the mold 210. The magnet 240 is typically embedded in the mold 210, under the first shaping surface. 210A, so as not to modify the shape of the molding cavity. Preferably, the magnet 240 is positioned centrally relative to the first shaping surface.Thus, it exerts a force substantially centered on the counter-mold, which allows the counter-mold to apply a substantially homogeneous pressure on the fibrous texture 230.

[0038] The shaping tool 200 may also comprise means 250 and 260 for centering the counter-mold 220 on the mold 210 so that the counter-mold 220 is positioned correctly positioned on the mold 210. Each centering means 250 can be formed by two magnets placed opposite each other on the mold 210 and the counter-mold 220. In another exemplary embodiment, each centering means 260 can be formed by a lug placed on the counter-mold 220, or on the mold 210, opposite a corresponding hole present on the mold 210, or respectively on the counter-mold 220.

[0039] In order not to hinder the shaping of the texture 230, the centering means 250 and 260 are placed outside the molding cavity, for example on the periphery of the mold 210 and the counter-mold 220. In other words, the centering means 250, 260 are placed outside the first shaping surface 210A and the second shaping surface 220A.

[0040] [Fig. 3] schematically and partially represents a shaping tool 300 according to a second embodiment of the invention.

[0041] The shaping tool 300 comprises at least one mold 310 and a counter-mold 320 respectively comprising a first shaping surface 310A and a second shaping surface 320A defining between them, in an operational configuration of the mold 310 and the counter-mold 320, a molding cavity in which a fibrous texture 330 is intended to be placed to be shaped.

[0042] The shaping tool 300 comprises a first magnet 340 placed on the mold 310 and a second magnet 370 placed on the counter-mold 320. The two magnets 340 and 370 are placed opposite each other on either side of the molding cavity and the fibrous texture 330 is intended to be placed between the two magnets 340 and 370. The first magnet 340 is typically embedded in the mold 310, under the first shaping surface 310A and the second magnet 370 is typically embedded in the counter-mold 320, under the second shaping surface 320A. The two magnets 340 and 370 make it possible to lock the counter-mold 320 on the mold 310 by magnetization when the shaping tool 300 is closed to place it in the operational configuration.

[0043] The shaping tool 300 may also comprise centering means 350 and 360 for centering the counter-mold 320 on the mold 310 so that the counter-mold 320 is positioned correctly on the mold 310. Each centering means 350 may be formed by two magnets placed opposite each other on the mold 310 and the counter-mold 320. In another exemplary embodiment, each centering means 360 may be formed by a lug placed on the counter-mold 320, or on the mold 310, opposite a corresponding hole present on the mold 310, or respectively on the counter-mold 320.

[0044] In order not to hinder the shaping of the texture 330, the centering means 350 and 360 are placed outside the molding cavity, for example on the periphery of the mold 310 and the counter-mold 320. In other words, the centering means 350, 360 are placed outside the first shaping surface 310A and the second shaping surface 320A.

[0045] [Fig.4] schematically and partially represents a shaping tool 400 according to a third embodiment of the invention.

[0046] The shaping tool 400 comprises at least one mold 410 and a counter-mold 420 respectively comprising a first shaping surface 410A and a second shaping surface 420A defining between them, in an operational configuration of the mold 410 and the counter-mold 420, a molding cavity in which a fibrous texture 430 is intended to be placed to be shaped.

[0047] The shaping tool 400 comprises four pairs of magnets 440, 450, 460, 470. The magnets 441, 451, 461 and 471 of the four pairs 440, 450, 460, 470 are placed on the mold 410 outside the molding cavity, i.e. outside the first shaping surface 410A. The magnets 442, 452, 462 and 472 are placed on the counter-mold 420 opposite the magnets 441, 451, 461 and 471 to form the four pairs 440, 450, 460, 470. Thus, the magnets 441, 442, 451, 452, 461, 462, 471, 472 are placed on the periphery of the mold 410 and the counter-mold 420, so that the texture 430 does not extend between the two magnets of a pair. They can be embedded at least in part in the mold 410 or the counter-mold 420. As in the other embodiments, the magnets of the pairs 440, 450, 460, 470 make it possible to lock the counter-mold 420 on the mold 410.

[0048] Although in the embodiment of [Fig. 4], the shaping tool is shown with four pairs of magnets, it does not depart from the invention if the shaping tool comprises a different number of magnets. The shaping tool may comprise at least two pairs of magnets. Preferably, it comprises at least three pairs of magnets, for example four pairs of magnets, so as to distribute the clamping force of the counter-mold on the mold.

[0049] Advantageously, the pairs of magnets are distributed homogeneously around the periphery of the mold and the counter-mold, so as to apply a substantially homogeneous pressure on the fibrous texture 430.

[0050] The presence of the different pairs of magnets 440, 450, 460, 470 also makes it possible to position the counter-mold 420 on the mold 410. However, the tool 400 may additionally comprise centering means 480 to improve the positioning of the counter-mold 420 on the mold 410. Each centering means 480 is preferably positioned between two pairs of magnets 440, 450, 460, 470.

[0051] As in the other embodiments, each centering means 480 can be formed by a lug 481 placed on the counter-mold 420, or on the mold 410, opposite a corresponding hole 482 present on the mold 410, or respectively on the counter-mold 420, as shown in [Fig. 4]. In another exemplary embodiment, not shown, each centering means can be formed by two magnets placed opposite each other on the mold 410 and the counter-mold 420.

[0052] Whatever the embodiment, the centering of the counter-mold on the mold can also be achieved using complementary geometries of the mold and counter-mold.

[0053] Whatever the embodiment, the magnets can be permanent magnets.

[0054] Regardless of the embodiment, the magnets may be electrically activatable magnets. The magnets are, for example, electromagnets. The shaping tool may thus also comprise a means for activating the magnets. This activation means may, for example, be configured to be able to circulate an electric current in each electromagnet, so as to generate an electromagnetic field encompassing the counter-mold of [Fig. 2], or an electromagnetic field between the two magnets of [Fig. 3] or an electromagnetic field between the two magnets within each pair of magnets in the case of [Fig. 4]. It is possible, for example, to choose to lock the counter-mold onto the mold when the current is flowing and to unlock the counter-mold when the flow of current is cut off.

[0055] Whatever the embodiment, the magnets can be in the form of circular or rectangular pellets or of any shape allowing adaptation to the design constraints of the shaping tool.

[0056] In the various embodiments, it has been considered that the shaping tool comprises only one mold and only one counter-mold. Of course, the shaping tool can be formed from a plurality of molds and a plurality of counter-molds arranged relative to each other so as to obtain the desired shape for the fiber texture, and therefore for the final part regardless of its complexity.

[0057] Regardless of the embodiment, the fibrous texture comprises, for example, silicon carbide fibers. The fibrous texture can be produced by stacking layers or plies obtained by two-dimensional weaving. The texture can also be produced directly in a single piece by three-dimensional weaving. By two-dimensional weaving, here is meant a conventional weaving method in which each weft thread passes from one side to the other of the threads of a single warp layer or vice versa. By three-dimensional weaving, here is meant a weaving in which warp threads pass through several layers of weft threads, or weft threads pass through several layers of warp threads.

[0058] The fibrous texture can also be produced by unidirectional fiber sheets, which can be obtained by automatic fiber placement, or by filament winding.

[0059] The fibrous texture can then, that is to say after having been shaped in the shaping tool according to an embodiment of the invention, be densified by a ceramic or organic matrix.

Claims

Claims

1. Conforming tool (200, 300, 400) for shaping a fibrous texture (230, 330, 430) comprising at least one mold (210, 310, 410) and a counter-mold (220, 320, 420) defining between them a molding cavity, the fibrous texture being intended to be placed in the molding cavity, characterized in that it comprises at least one first magnet (240, 340, 441) present on the mold opposite the counter-mold and in that the counter-mold is configured to position itself and lock with the mold by magnetization with the first magnet.

2. A shaping tool (200) according to claim 1, wherein the counter-mold (220) is made of ferromagnetic material.

3. Conforming tool (300) according to any one of claims 1 or 2, comprising at least one second magnet (370) present on the counter-mold (320) opposite the first magnet (340) and configured to magnetize with the first magnet.

4. Conforming tool (400) according to any one of claims 1 to 3, comprising at least two pairs (440, 450, 460, 470) of magnets present on the periphery of the mold and the counter-mold, so as to be outside the molding cavity, within each pair of magnets, a first magnet (441, 451, 461, 471) being placed on the mold opposite a second magnet (442, 452, 462, 472) placed on the counter-mold.

5. Conforming tool (200, 300, 400) according to any one of claims 1 to 4, comprising a centering means (250, 260, 350, 360, 480) of the counter-mold on the mold.

6. A shaping tool according to claim 5, wherein the centering means comprises at least one pair of magnets placed opposite each other on the mold and the counter-mold.

7. A shaping tool (400) according to any one of claims 5 or 6, wherein the centering means (480) comprises a lug (481) placed on the mold or the counter-mold, and a corresponding hole (482) formed in the counter-mold or the mold, respectively.

8. A shaping tool according to any one of claims 1 to 7, wherein the magnets are permanent magnets.

9. A shaping tool according to any one of claims 1 to 7, wherein each first magnet is an electromagnet.

10. A shaping tool according to claim 9, comprising electromagnet activating means configured to be able to cause an electric current to flow through each of said electromagnets.

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