TOOL AND METHOD FOR POSITIONING AND SHAPING AN ADHESIVE FILM FOR BONDING IN A CAVITY OF A PART

Abstract

Tool (50) and method for positioning and shaping an adhesive film (28), the tool comprising: a body (52) comprising a first part (60) which is made of porous material and which comprises an external surface (65) of predetermined shape on which an adhesive film (28) is intended to be positioned, and a support (54) connected to said body (52) and comprising at least one port (56) which is connected to said first part (60) by at least one internal channel (58, 59), said at least one port (56) being configured to be connected to a vacuum source so that said adhesive film (28) (is held in shape and position on said surface 65) by suction effect through the porous material of the first part (60). Abstract figure: figure 3

Description

Title of the invention: TOOL AND METHOD FOR POSITIONING AND SHAPING AN ADHESIVE FILM FOR BONDING IN A CAVITY OF A ROOM Technical field of the invention

[0001] The invention relates to a tool and a method for positioning and shaping an adhesive film, in particular with a view to bonding it in a cavity of a part, in particular an aeronautical part. Technical background

[0002] In a well-known manner, an aircraft turbomachine extends along a longitudinal axis and comprises, from upstream to downstream in the direction of gas flow, a fan, a low-pressure compressor, a high-pressure compressor, an annular combustion chamber, a high-pressure turbine, a low-pressure turbine and finally a combustion gas exhaust nozzle.

[0003] The fan is composed of a central disc rotating around an axis of rotation. The axis of rotation is for example the longitudinal axis of the turbomachine. The central disc is surmounted by a plurality of blades allowing the initial compression of the air entering the turbomachine. The blades are possibly surrounded by a retention casing allowing the blades to be retained in the event of their breakage.

[0004] A fan blade 10, such as that shown in [Fig. 1], is generally composed of a blade 12 having an aerodynamic profile comprising a leading edge 14 and a trailing edge 16 connected by a pressure face 18, and an extrados face 20 opposite the pressure face. The blade 12 further comprises an upper end 22 and an opposite lower end connected to a root 24. The root 24 is intended to cooperate with a corresponding cell of the central disk to fix the blade 10 on the central disk.

[0005] Furthermore, in order to reduce the weight of the fan, the blade 12 is for example made of a composite material, typically an organic matrix composite (OMC) material. The composite material comprises a polymer matrix, for example a thermoplastic or thermosetting matrix and fibers, such as carbon fibers or glass fibers, embedded in the matrix.

[0006] Furthermore, in order to protect the leading edge 14 from wear by erosion and / or degradation caused by impacts with foreign bodies, the leading edge 14 is covered with a metal protective shield 26. The shield 26 is assembled and fixed to the leading edge 14 by gluing. For this purpose, the shield 26 is coated with an adhesive film 28, then the shield 26 is assembled on the leading edge 14. The assembly is then subjected to a heat treatment in order to ensure the polymerization of the adhesive film. The shield 26 is thus fixed on the leading edge 14.

[0007] The shield 26 has a generally elongated shape and has a generally dihedral shape with two wings 29, 30 which are connected together at a connecting edge 32 (see [Fig. 2]). The wings 29, 30 define between them a longitudinal cavity 34 in which the leading edge 14 of the blade 12 is intended to be housed. The adhesive film 28 is previously positioned inside the cavity 34 so as to be interposed between the leading edge 14 and the connecting edge 32, and between the intrados face 18 and the wing 29, and between the extrados face 20 and the wing 30.

[0008] The leading edge 14 of the blade 12 may have a complex shape. The shield 26 may therefore also have a complex shape, which results in a complex shape of its cavity 34 and in difficulties in correctly positioning the adhesive film 28 in the cavity 34 before attaching the shield 26 to the leading edge 14 of the blade 12.

[0009] There is therefore a need to facilitate this positioning and to ensure that the adhesive film is correctly positioned in the cavity of the shield.

[0010] The invention provides a simple, effective and economical solution to this need. Summary of the invention

[0011] To this end, the invention proposes a tool for positioning and shaping an adhesive film, comprising: - a body comprising a first part which is made of porous material and which comprises an external surface of predetermined shape on which an adhesive film is intended to be positioned, and - a support connected to said body and comprising at least one first port which is connected to said first part by at least one internal channel, said at least one first port being configured to be connected to at least one vacuum source so that said adhesive film is held in shape and in position on said surface by suction effect through the porous material of the first part.

[0012] The tooling allows an adhesive film to be positioned precisely and reliably, at any point on the adhesive film. The external surface of the first part of the body is easily accessible and receives the adhesive film which can be directly applied by an operator. The particularity of this first part is that it is made of porous material and that it is connected to a vacuum or suction source so that air can be sucked through this porous material. After positioning the adhesive film on the porous material, the suction of the air will cause a vacuum between the adhesive film and the external surface of the porous material and therefore the application of the adhesive film on this external surface. This vacuum is sufficient to maintain the position of the adhesive film on the first part during assembly of the shield on the adhesive film. If necessary, the air suction can be interrupted and the adhesive film can be repositioned on the body before reactivating the air suction. The invention therefore simplifies the positioning and bonding of the adhesive film at the bottom of the cavity of a shield, but could also be used to position and bond an adhesive to another part, particularly an aeronautical part.

[0013] The tooling according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: • the external surface forms a dihedral and comprises two faces inclined relative to each other and intended to receive respectively distinct parts of the adhesive film; • said external surface has a general shape elongated along an axis of elongation, and is twisted along this axis of elongation; • the body has a general shape of a blade of an aeronautical engine, said first part of the body having a shape of a leading or trailing edge of such a blade; • said porous material is a porous metal, and for example a porous steel, bronze or brass; it is for example produced by hooping metal particles; • the body comprises a second part made of a non-porous material and interposed between the first part and the support, said at least one channel passing through this second part or being formed partly in this second part; • the non-porous material is a metal:

[0014] — the body is formed by a block of material with double density, a first density at level of the first porous part of the body and the block, and a second higher density at the level of the second solid part of the body and the block;

[0015] — the metallic materials of the first and second parts of the body and the block may be identical;

[0016] - the tooling further comprises a flexible membrane which is intended to cover the body and at least one face of the support, the support comprising at least one second port which is connected to said face by an internal channel and which is configured to be connected to at least one vacuum source so that the membrane is held tight on the body by suction effect; and

[0017] - the covering membrane is fixed to the support by a fixing and sealing system, which extends around said body.

[0018] The present invention also relates to a method for positioning and shaping an adhesive film with a view to bonding it in a cavity of a part, in particular an aeronautical part, this method comprising the following steps: a. position an adhesive film on the external surface of the first part of the tool body as described above, b. connecting said at least one first port of the tooling to a vacuum source so as to maintain the shape and position of the adhesive film on said surface by suction effect through the porous material of the first part, and c. position a part on the adhesive film, this part comprising a cavity of a shape complementary to that of the first part and in which the adhesive film is intended to be stuck.

[0019] The method according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another: • the part is a metal shield for the leading or trailing edge of an aircraft engine blade; • the part forms a dihedral and comprises two wings connected together to form a connecting edge, the two wings being intended to cover respectively distinct parts of the adhesive film; • the suction effect is maintained during step c) and is stopped after step c) which is followed by a step d) of removing the part with the adhesive film stuck in the cavity; • the suction effect is maintained during step c) and is stopped after step c) which is followed by a step d) of removing the part with the adhesive film (28) stuck in the cavity; and • the method comprises, after step c), the following steps:

[0020] d) covering the part and the body with a flexible membrane which also covers one face of the support,

[0021] e) connecting said at least one second port of the tool to a vacuum source so as to maintain the membrane clamped on the part and the body by suction effect Brief description of the figures

[0022] Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which:

[0023] [Fig-1] [Fig.l] is a schematic perspective view of a fan blade;

[0024] [Fig.2] [Fig.2] is a partial schematic and perspective view of the dawn of the [Fig.2], and shows more particularly its leading edge and its shield;

[0025] [Fig.3] [Fig.3] is a schematic perspective view of a tool according to the invention;

[0026] [Fig.4] [Fig.4] is a schematic view, partially in section and in perspective, of the tooling of [Fig.3], and shows a vacuum circuit for this tooling;

[0027] [Fig.5] [Fig.5] is a larger scale view of a first detail of [Fig.4], and shows in particular a detail of the vacuum circuit; and

[0028] [Fig.6] [Fig.6] is an enlarged view of a second detail of [Fig.4], and shows in particular another detail of the vacuum circuit. Detailed description of the invention

[0029] Figures 1 and 2 have been described in the above.

[0030] Figures 1 and 2 may be used to illustrate a blade 10 which may be obtained with the tooling and the method according to the invention.

[0031] Figures 3 to 6 illustrate an example of embodiment of a tool 50 according to the invention.

[0032] The tooling 50 is designed to position and shape an adhesive film 28, in particular but not exclusively in the cavity 34 of a shield 26 as described above.

[0033] The tool 50 essentially comprises two parts, namely a body 52 and a support 54 connected to the body 52. ​​The support 54 can form a base or a plinth on which the body 52 is positioned. It is therefore understood that the body 52 is preferably located on, that is to say above, the support 54.

[0034] In the example shown, the support 54 has a general plate shape and the body 52 is located on an upper face 55 of this plate. The support 54, or the plate, has a general elliptical shape in the example shown. The support 54 or its plate has a thickness denoted EL

[0035] The face 55 of the support 54 or its plate comprises a central part intended to receive the body 52, and a peripheral part which extends all around the body 52 and the central part. In the example shown, the central part of the face 55 is hollowed out to receive the body 52 by complementarity of shapes.

[0036] The support 54 is equipped with at least one port 56 and the tooling 50 comprises at least one internal channel 58, 59 for connecting the port(s) 56 to the body 52.

[0037] It can be seen in the drawings that the port(s) 56 are located on the sides or peripheral edge of the support 54.

[0038] In the example shown, a first port 56a has an orientation parallel to a plane of the support 54 and is located at a first end of the support 54. The port 56a has a generally cylindrical shape and has an external diameter which is less than the aforementioned thickness E1. This first port 56a is connected to one end 58a of a first channel 58 formed in the support 54. This channel 58a has an opposite end 58b which opens onto the upper face of the support 54 or its plate, in particular at the level of its central part intended to receive the body 52. ​​A sealing O-ring 58c preferably surrounds the outlet of this end 58b of the channel 58.

[0039] Port 56a is intended to be connected to a vacuum or suction source, such as an air pump, in order to draw air through channel 58, as illustrated by the arrows in the drawings.

[0040] In the example shown, a second port 56b has an orientation parallel to a plane of the support 54 and is located at a second end of the support 54, opposite the first port 56a. The port 56b has a generally cylindrical shape and an external diameter which is less than the aforementioned thickness E1. This port 56b is connected to one end 59a of a second channel 59, an opposite end 59b of which opens onto the upper face 55 of the support 54 or its plate, in particular in its peripheral part intended to extend around the body 52.

[0041] In this configuration, a membrane 61 may be used to hold the part on the film 28 during bonding, as explained in more detail below.

[0042] The membrane 61 is flexible and is intended to cover the body 52 and at least part of the face 55 of the support 54. The end 59b of the channel 59 which opens onto the face 55 forms an orifice or a peripheral groove which extends over all or part of the body 52, as can be seen in [Fig.3].

[0043] The outer periphery of the membrane 61 can be fixed in a sealed manner to the outer periphery of the support 52 by a suitable fixing and sealing system 63.

[0044] The body 52 comprises two parts in the example shown.

[0045] A first part 60, or upper part, is made of porous material and comprises an external surface 61 of predetermined shape on which the aforementioned adhesive film 28 is intended to be positioned.

[0046] In the case where the adhesive film 28 is intended to be glued in the cavity 34 of a shield 26, the body 52 or its first part 60, preferably has a general shape in the form of a portion of a blade. The first part 60 of the body is in fact intended to reproduce the shape and dimensions of the leading edge 14 (or trailing edge 16) of the blade on which the shield 26 is intended to be glued.

[0047] The external surface 61 of the first part 60 has a dihedral shape and comprises two faces 64, 66 inclined relative to each other and intended to receive respectively distinct parts of the adhesive film 28.

[0048] The external surface 61 may have a general shape elongated along an axis of elongation, and be twisted along this axis of elongation as in the example shown.

[0049] The body 52 may comprise a second part 62 made of a non-porous material and interposed between the first part 60 and the support 54.

[0050] It can be seen in the drawings that the second part 62 comprises faces 70, 72 which extend in the extension of the faces 64, 66, respectively.

[0051] The body 52 may comprise, at the level of this second part 62 for example, a base 74 for fixing on the support 54. This base 74 may be engaged in the hollow part of the face 55 of the support 54 or of its plate and have a shape complementary to this hollow part in order to guarantee correct positioning of the body 52 54 on the support once the assembly has been carried out.

[0052] As seen in the drawings, the body 52 includes a second internal channel 59 that extends from the channel 58 into the first portion 60. The channel 59 passes through or is formed in the second portion 62 and includes an end 59a in fluid communication with the end 58b of the channel 58, and an opposite end 59b that opens into the interior of the first portion 60. The end 59b is surrounded by the seal 58c in the example shown.

[0053] In the example shown, channel 59 has a vertical orientation and extends through base 74 aligned with end 58b of channel 58.

[0054] The suction of air through the port 56a causes a suction or suction phenomenon at the external surface 61 of the first part 60, which makes it possible to maintain the shape and position on this surface 61 of the adhesive film 28 previously placed on the surface 61.

[0055] The porous material of the first portion 60 is preferably a porous metal. It may be a porous steel, bronze, or brass. The non-porous material of the second portion 62 is preferably a metal.

[0056] The present invention also relates to a method for positioning and shaping an adhesive film with a view to bonding it in a cavity of a part, in particular an aeronautical part. As mentioned above, the method is particularly suitable, but not exclusively, for bonding an adhesive film in the cavity of a protective shield for a blade, in particular a turbomachine.

[0057] The method comprises the following steps:

[0058] a) positioning the adhesive film 28 on the external surface 61 of the first 60 part of the body 52 of the tool 50,

[0059] b) connecting the port 56a of the tool 50 to the vacuum source so as to maintain the adhesive film 28 in shape and position on the surface 61 by suction effect through the porous material of the first part 60, and

[0060] c) positioning a part on the adhesive film 28, this part comprising a cavity of a shape complementary to that of the first part 60 and in which the adhesive film 28 is intended to be stuck.

[0061] In the case of using a flexible membrane 61, the method may comprise the following steps:

[0062] d) covering the part and the body 52 with a flexible membrane 61 which also covers a face 55 of the support 52,

[0063] e) connecting said at least one second port 56 of the tool 50 to a vacuum source so as to maintain the membrane 61 clamped on the part and the body 52 by suction effect.

[0064] Before cutting the vacuum draw through the first port, the part, the body 52 and the face 55 of the body 54 are covered with the membrane 61. The vacuum is created through the second port so that the membrane 61 is pressed against the body 52 and the part. By pressing the part, the membrane 61 exerts a uniform pressing force on it which consequently sticks to the adhesive film 28. Once this is done, the suction through the ports 59 can be stopped. The membrane 61 is removed and the part on which the adhesive film is stuck can also be removed and be ready for use.

[0065] In the example described above, the part is a metal shield 26 of the leading edge 14 or trailing edge 16 of an aeronautical engine blade 10.

[0066] The part or shield 26 forms a dihedron and comprises two wings 29, 30 connected together to form a connecting edge 32, the two wings 29, 30 being intended to cover respectively distinct parts of the adhesive film 28 and to extend over the two faces 64, 66 of the surface 61.

[0067] The suction or suction effect is maintained during step c) and is stopped after step c) which is followed by a step d) of removing the part with the adhesive film 28 stuck in the cavity.

[0068] In non-detailed variants, it would be possible to envisage different films of glue on the same part, and in particular on different zones of the part, the vacuum drawing being able for example to be sequenced from one zone to another, or more significant in one zone than another, for example to control the distribution of the thickness of the film, etc.

Claims

Claims

1. Tool (50) for positioning and shaping an adhesive film (28) for an aeronautical part, comprising: - a body (52) comprising a first part (60) which is made of porous material and which comprises an external surface (65) on which an adhesive film (28) is intended to be positioned, the external surface (65) forming a dihedral and comprising two faces (64, 66) inclined relative to each other and intended to respectively receive distinct parts of the adhesive film (28), and - a support (54) connected to said body (52) and comprising at least one first port (56, 56a) which is connected to said first part (60) by at least one internal channel (58), said at least one first port (56) being configured to be connected to at least one vacuum source so that said adhesive film (28) is held in shape and position on said surface (65) by suction effect through the material porous of the first part (60).

2. Tooling (50) according to claim 1, wherein said external surface (65) has a generally elongated shape along an axis of elongation, and is twisted along this axis of elongation.

3. Tooling (50) according to one of the preceding claims, in which the body (52) has a general shape of a blade of an aeronautical engine, said first part (60) of the body (52) having a shape of a leading edge (14) or trailing edge (16) of such a blade.

4. Tooling (50) according to one of the preceding claims, wherein said porous material is a porous metal, and for example a porous steel, bronze or brass.

5. Tool (50) according to one of the preceding claims, in which the body (52) comprises a second part (62) made of a non-porous material and interposed between the first part (60) and the support (54), said at least one channel (58, 59) passing through this second part (62) or being formed partly in this second part (62).

6. Tooling (50) according to the preceding claim, wherein the non-porous material is a metal.

7. Tool (50) according to one of the preceding claims, in which it further comprises a flexible membrane (61) which is intended to cover the body (52) and at least one face (55) of the support (54), the support (54) comprising at least one second port (56, 56b) which is connected to said face (55) by an internal channel (59) and which is configured to be connected to at least one vacuum source so that the membrane (61) is held tight on the body (52) by suction effect.

8. Tooling (50) according to the preceding claim, in which the membrane (61) is fixed to the support (52) by a fixing and sealing system (63), which extends around said body (52).

9. Method for positioning and shaping an adhesive film (28) for bonding it in a cavity (34) of an aeronautical part, this method comprising the following steps: a. positioning an adhesive film (28) on the external surface (65) of the first part (60) of the body (52) of the tool (50) of one of the preceding claims, b. connecting said at least one first port (56) of the tool (50) to a vacuum source so as to maintain the shape and position of the adhesive film (28) on said surface (65) by suction effect through the porous material of the first part (60), and c. positioning a part on the adhesive film (28), this part comprising a cavity (34) of a shape complementary to that of the first part (60) and in which the adhesive film (28) is intended to be bonded.

10. Method according to claim 9, in which the part is a metal shield (26) of the leading edge (14) or trailing edge (16) of an aeronautical engine blade (10).

11. A method according to claim 9 or 10, wherein the part forms a dihedron and comprises two wings (29, 30) connected together to form a connecting edge (32), the two wings (29, 30) being intended to cover respectively distinct parts of the adhesive film (28).

12. Method according to one of claims 9 to 11, in which the suction effect is maintained during step c) and is stopped after step c) which is followed by a step d) of removing the part with the adhesive film (28) stuck in the cavity (34).

13. Method according to one of claims 9 to 12, the tooling being as defined in claim 7 or 8, in which it comprises, after step c), the following steps: d) covering the part and the body (52) with a flexible membrane (61) which also covers a face (55) of the support (52), e) connecting said at least one second port (56) of the tooling (50) to a vacuum source so as to maintain the membrane (61) clamped on the part and the body (52) by suction effect.

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