Method for locating a mark on a turbomachine casing

Abstract

Method for locating a mark (46, 48) on a casing (10) of a turbomachine (1) of an aircraft, characterized in that it comprises: a) a step of visually inspecting the arms (16), the outer surface (12a) of the internal shroud (12) and the inner surface (14a) of the external shroud (14), and, in the event that at least one mark (46, 48) is detected at step a), b) a step of manually mounting a visual inspection device (32) around the inner end (16a) or outer end (16b) of one or more of the arms (16), and c) a step of determining the location of the at least one mark (46, 48) in a zone (Z1, Z2, Z3) of the casing (10).

Description

[0001]

[0002] Technical field of the invention

[0003] The present invention relates to a method for locating a mark on a casing of a turbomachine, in particular an aircraft, as well as a tool for implementing this method.

[0004] Technical background

[0005] The technical background includes in particular documents US-A1-2004 / 147893, EP-A1-1 582 838 and EP-A1-3 067 140.

[0006] Conventionally, a turbomachine comprises, from upstream to downstream with reference to the flow of gases in this turbomachine, a fan, one or more compressors, an annular combustion chamber and one or more turbines.

[0007] A turbomachine comprises several casings which are fixed elements, i.e. stator elements, as opposed to rotor elements which are mobile in rotation.

[0008] A turbomachine casing generally has a general annular shape around an axis which coincides with the longitudinal axis of the turbomachine. This longitudinal axis is generally the axis of rotation of the turbomachine rotors and the axis along which the gases flow inside the turbomachine.

[0009] In the present application, the casing is a casing essentially comprising two coaxial annular ferrules, respectively internal and external, and arms which extend between the ferrules and connect them together.

[0010] This type of casing can be located between two compressors of the turbomachine and is then called an intermediate casing. This type of casing can also be located downstream of the turbines of the turbomachine and be called an exhaust casing.

[0011] The two shells define between them a portion of the gas flow path. The arms that extend between the shells thus cross the path and divide it into several sections. These arms can have different shapes and some can be hollow and include internal cavities that open towards the inside of the inner shell and towards the outside of the outer shell. These hollow arms allow the passage of services, such as cables and pipes, through the casing, from the outside to the inside or vice versa.

[0012] When producing this type of casing and before installing it on a turbomachine, it is important to check its condition. It is also important to check the condition of this type of casing during a maintenance operation on the turbomachine, when it is dismantled or when it is still attached under the wing of an aircraft, for example.

[0013] The condition of the casing is checked during a control operation which includes a step of locating any marks on the casing. In this application, the term "mark" means an element on the casing which is not intentional and which is visible, i.e. which can be spotted with the naked eye by an operator. A mark is, for example, wear, a scratch, an impact, a defect, etc. A mark may, for example, have a length of around 1 to 2 mm and a depth of less than 1 mm.

[0014] During the inspection operation, the operator checks for the presence of marks on the casing. If a mark is detected, it must be recorded and specifically located so that it can be analyzed later. The following analysis is necessary to determine whether the mark is minor and inconsequential, whether the mark is significant and requires special maintenance of the casing, or whether the mark is too significant and requires the casing to be scrapped and replaced.

[0015] For example, if the mark is an impact that forms a hollow in the casing, the following maintenance would allow the casing to be repaired by, for example, re-lining, adding material to the hollow, grinding by machining, etc.

[0016] During this operation, the location of the mark is of fundamental importance because a mark located near the junction of an arm to one of the shells, for example, is not treated in the same way as an identical mark located on one of the shells and at a distance from the nearest arms. Marks located near the junctions of the arms to the shells can in fact have a direct impact on the mechanical strength and therefore the service life of the casing. It is therefore important during this operation to locate the marks on the casing as precisely as possible in order to be able to analyze them accordingly.

[0017] In current technology, the location of a mark on the casing is carried out by hand using a ruler or similar. After visually identifying a mark, the operator locates it with a ruler, for example by measuring its distance from a junction between an arm and one of the shells. This method is long and imprecise, particularly due to the complex shape of the arms. The same mark may not be located in exactly the same place by two different operators, and also by the same operator making two successive measurements. It is indeed not possible to have good repeatability of measurements with current technology. Errors of interpretation may then be generated.

[0018] There is therefore a need to identify a solution to this problem that makes it possible to make brand localization more reliable, increase the repeatability of this type of localization and also reduce its duration.

[0019] Summary of the invention

[0020] The invention relates to a method for locating a mark on an aircraft turbomachine casing, this casing comprising two coaxial annular shells, respectively internal and external, and arms which extend between the shells and which each comprise an internal end connected to an external annular surface of the internal shell and an external end connected to an internal annular surface of the external shell, characterized in that it comprises: a) a step of visual inspection of the arms, of the external annular surface of the internal shell, and of the internal annular surface of the external shell, and in the case where at least one mark is detected in step a), b) a step of manual mounting of a visual inspection device around the internal or external end of one or more of the arms on which said at least one mark is detected,the or each control device being configured to cover a portion of the inner end of an arm as well as a portion of the outer annular surface of the inner ferrule extending around this inner end, or to cover a portion of the outer end of the arm as well as a portion of the inner annular surface of the outer ferrule extending around this outer end, and c) a step of determining the location of said at least one mark in an area of ​​the casing:,

[0021] - said at least one mark being located in a first zone of the casing, which is a junction zone of one of the arms to one of the ferrules, when said at least one mark is hidden by the control device in step b),

[0022] - said at least one mark being located in a second zone of the casing, which is a zone of an arm excluded from the junction zones of this arm, when said at least one mark is located on the annular surface of the shell and is not hidden by the control device in step b), and

[0023] - said at least one mark being located in a third zone of the casing, which is an area of ​​the casing excluded from the junction zones of the arms, when said at least one mark is located on the arm and is not hidden by the control device in step b).

[0024] The invention makes it possible to facilitate and make more reliable the location of mark(s) on a turbomachine casing thanks to the use of one or more control device(s). The or each control device is mounted at one end of an arm, and therefore its inner end located on the side of the inner shell or its outer end located on the side of the outer shell. Each control device preferably has a shape and dimensions adapted to best match the shape of the arm at this end. The shape and dimensions of the device are further advantageously predetermined so that the control device covers the most sensitive and most fragile areas of the casing, namely the areas which are located at the junctions between the arms and the shells. These areas are called first areas. The other areas of the casing are less sensitive and are less affected by the presence of marks.These other zones are second zones which are located on the ferrules at a distance from the aforementioned junctions, and third zones which are located on the arms at a distance from the junctions.

[0025] It is thus understood that the or each mark can be easily and quickly located in one of these zones. If a mark disappears because it is hidden by the control device when it is mounted on the arm, then this mark is located in the first zone of this arm. If a mark is not hidden by the control device and is located on the ferrule, then this mark is located in a second zone next to this arm. If a mark is not hidden by the control device and is located on the arm, then this mark is located in the third zone of this arm. In the case where a mark is located in the first zone of an arm, then the method according to the invention could be followed by a maintenance method in which the casing would be repaired to remove or reduce the mark for example.

[0026] The method according to the invention may comprise one or more of the following features or steps, taken in isolation from one another, or in combination with one another:

[0027] - the method comprises, between steps b) and c): i) a first intermediate step in which at least one line is drawn on the arm and / or the external annular surface of the inner ferrule and / or the internal annular surface of the outer ferrule, along edges of the or each control device, and ii) a second intermediate step in which the or each control device is removed from the casing, and in which step c) is carried out as a function of the position of said at least one mark relative to the or each line drawn; it is therefore understood that the location of the or each mark in one of the aforementioned zones can be done after removal of the control device, thanks to the line or lines drawn on the casing which make it possible to delimit these zones;

[0028] - said at least one line is drawn with a felt-tip pen;

[0029] - in step b): a first control device is mounted around an inner end of a first arm on which said at least one mark is detected, and a second control device is mounted around an inner end of a second adjacent arm on which said at least one mark (46, 48) is detected;

[0030] - in step b): a third control device is mounted around an outer end of the first arm on which said at least one mark (46, 48) is detected, and a fourth control device is mounted around an outer end of the second adjacent arm on which said at least one mark (46, 48) is detected;

[0031] - the or each control device comprising two blocks, step b) comprises the positioning of the two blocks on either side of the arm;

[0032] - the two blocks are fixed or held together; for example by magnets which can be integrated into the blocks or by fixing members; alternatively, the two blocks could simply be held together manually;

[0033] - each of the blocks is made of a single piece;

[0034] - each of the blocks is produced by additive manufacturing.

[0035] The present invention also relates to a tool for implementing a method as described above, the tool comprising at least one visual inspection device configured to be mounted around an external or internal end of an arm of the casing, the or each inspection device comprising two blocks configured to be mounted on either side of the arm, each of these blocks comprising:

[0036] - a first part configured to cover a part of the inner annular surface of the outer shell or of the outer annular surface of the inner shell,

[0037] - a second part configured to cover a part of an intrados or extrados face of the arm, and

[0038] - a junction between the first and second portions configured to extend at a fillet of the face portion with the annular surface portion.

[0039] 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:

[0040] - each of the blocks has a general L shape;

[0041] - each of the blocks comprises projecting pads configured to bear on the casing, the remainder of each of the blocks being configured to be set back from the casing to define a mounting clearance for the or each control device; this mounting clearance makes it possible to compensate for any variations in the dimensions of the casing due to manufacturing tolerances;

[0042] - each of the blocks comprises a longitudinal edge configured to form a tracing reference;

[0043] - each of the blocks comprises at least one portion configured to be applied against a complementary portion of the other of the blocks, so as to allow the two blocks to be fixed or held in place with respect to each other;

[0044] - the two blocks of the same device have an identical color which is different from the color of the blocks of the other device, or from the colors of the blocks of the other devices;

[0045] - each of the blocks includes an indication of mounting on the internal or external end of the arm; this indication may be integrated into each block and may for example be a protruding or hollow mention, such as in particular “out” and “in” with reference to mounting on the external end (“out” in English) or on the internal end (“in” in English) of the arm;

[0046] - the tooling comprises at least two independent control devices configured to be mounted around internal ends of arms, and two other independent control devices configured to be mounted around external ends of arms; in the case where the casing to be inspected would have two types of arms, the tooling could then comprise only these four control devices which would be used to be mounted on the ends of the different arms;

[0047] - the control devices are all different;

[0048] -- each of the blocks is made of a single piece;

[0049] -- each of the blocks is made by additive manufacturing.

[0050] Brief description of the figures

[0051] 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:

[0052] [Fig.1] Figure 1 is a partial schematic view in axial section of an aircraft turbomachine,

[0053] [Fig.2] Figure 2 is a perspective view of a casing for an aircraft turbomachine, such as that of Figure 1,

[0054] [Fig.3] Figure 3 is an enlarged view of part of Figure 2 and shows the junction between an inner end of an arm and the inner shell of the casing,

[0055] [Fig.4] Figure 4 is a perspective view of a tool for implementing a method according to the invention for locating a mark on a turbomachine casing, this tool here comprising several independent control devices,

[0056] [Fig.5] Figure 5 is a partial schematic perspective view of a casing on which two control devices are mounted at the external ends of two adjacent arms, these control devices being able to be different depending on the shapes and dimensions of the arms,

[0057] [Fig.6] Figure 6 is a partial schematic perspective view of a casing on which two control devices are mounted at the internal ends of two adjacent arms, these control devices being able to be different depending on the shapes and dimensions of the arms,

[0058] [Fig.7a] Figure 7a is a schematic perspective view of a junction between an arm and a ferrule and shows the mounting of a control device at this junction, during a method according to the invention;

[0059] [Fig.7b] Figure 7b is a schematic perspective view of a junction between an arm and a ferrule and shows the mounting of a control device at this junction, during a method according to the invention;

[0060] [Fig.7c] Figure 7c is a schematic perspective view of a junction between an arm and a ferrule and shows the mounting of a control device at this junction, during a method according to the invention;

[0061] [Fig.8] Figure 8 is a schematic perspective and sectional view of a control device mounted on the junction of an arm; and

[0062] [Fig.9] Figure 9 is a schematic perspective view of a junction between an arm and a ferrule and shows the tracing of lines on the casing as well as the location of marks on the casing, during a method according to the invention.

[0063] Detailed description of the invention

[0064] Figure 1 describes a turbomachine 1 which comprises, in a conventional manner, an axis of rotation X, a fan S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1c, a high-pressure turbine 1d, a low-pressure turbine 1e and an exhaust nozzle 1h. The high-pressure compressor 1b and the high-pressure turbine 1d are connected by a high-pressure shaft 2 and form with it a high-pressure (HP) body. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and form with it a low-pressure (LP) body.

[0065] The blower S is driven by a blower shaft 4 which can be connected to the LP shaft 3 by means of a reducer 6. This reducer 6 is generally of the planetary or epicyclic type.

[0066] The turbomachine 1 comprises several casings which are stator elements. An example of casing 10 is illustrated in Figure 2. This type of casing comprises two coaxial annular shells, respectively internal 12 and external 14, and arms 16 which extend between the shells 12, 14 and connect them together.

[0067] The shells 12, 14 define between them a portion of the gas flow path in the turbomachine 1. When the casing 10 is mounted between the LP compressor 1 a and the HP compressor 1 b, this casing 10 is called the intermediate casing and is referenced 18 in FIG. 1. The shells 12, 14 then define between them the portion of the path extending between the LP compressors 1 a and HP 1 b. When the casing 10 is mounted downstream of the LP turbine 1 e, this casing 10 is called the exhaust casing and is referenced 20 in FIG. 1. The shells 12, 14 then define between them the portion of the path at the outlet of the LP turbine 1 e.

[0068] The shells 12, 14 may conventionally comprise at their upstream and downstream ends annular flanges 22 for attachment to complementary annular flanges of other casings of the turbomachine 1 (figure 2). The internal shell 12 may be connected to a partition 24 of the casing 10.

[0069] The arms 16 divide the vein located between the ferrules 12, 14 into several sectors. The arms 16 may have a radial orientation relative to the X axis or be inclined relative to radii to the X axis.

[0070] The arms 16 each comprise an inner end 16a connected to an outer annular surface 12a of the inner shroud 12 (FIGS. 2 and 3), and an outer end 16b connected to an inner annular surface 14a of the outer shroud 14 (FIG. 2). Each of the arms 16 has an aerodynamic profile and comprises a leading edge 16c (upstream), a trailing edge 16d (downstream) and two lateral faces 16e, 16f extending between the leading edge 16c and the trailing edge 16d (FIG. 3). One of the faces 16e may have a concave curved shape and form a pressure face, and the other of the faces 16f may have a convex curved shape and form a suction face (FIG. 3).

[0071] The surfaces of the casing 10 located in the vein are separated into three zones:

[0072] - the first zones Z1 are the junction zones of the arms 16 to the ferrules 12, 14 and therefore the connection zones and therefore the fillets 26 for connecting the ends 16a, 16b of the arms to the surfaces 12a, 14a of the ferrules 12, 14; figure 3 shows one of these zones Z1 which here extends around an internal end 16a of an arm 16;

[0073] - the second zones Z2 are the zones of the surfaces 12a, 14a of the ferrules 12, 14 located between the zones Z1 and therefore at a distance from the junctions of the arms 16; figure 2 shows these zones Z2; and

[0074] - the third zones Z3 are the zones of the arms 16 and in particular of their faces 16e, 16f located between the zones Z1 and therefore at a distance from the junctions of the arms 16; figure 2 shows these zones Z3.

[0075] In Figure 3, the zone Z1 is separated from a zone Z2, located on the side of the intrados face 16e of the arm 16, by an imaginary line L1 which is located on the surface 12a, 14a and which extends substantially parallel to a chord of the arm 16 or to the axis X of the casing 10. The zone Z1 is separated from another zone Z2, located on the side of the extrados face 16f of the arm 16, by an imaginary line L2 which is located on the surface 12a, 14a and which extends substantially parallel to the chord of the arm 16 or to the axis X of the casing 10. The zone Z1 is further separated from the zone Z3, located on the faces 16e, 16f of the arm 16, by imaginary lines L3, L4 located respectively on the intrados 16e and extrados 16f faces of the arm 16. The present invention proposes a method for locating a mark on a turbomachine casing such as that described above, as well as tooling for implementing this method.

[0076] Figure 4 shows an embodiment of a tool 30 for implementing the method. This tool 30 comprises one or more visual control devices 32 - which are four in number in the example shown.

[0077] Each device 32 is configured to be mounted around an outer 16b or inner 16a end of an arm 16 of the casing 10 to cover an area Z1.

[0078] Each control device 32 preferably comprises two blocks 32a, 32b configured to be mounted on either side of the arm 16. One of the blocks 32a is intended to be mounted on the side of the intrados face 16e of the arm 16 and the other of the blocks is intended to be mounted on the side of the extrados face 16f of the arm 16. Each of the blocks 32a, 32b has a generally elongated shape and is intended to extend from the leading edge 16c to the trailing edge 16d of the arm in the mounted position on the arm 16.

[0079] More particularly, as can be seen in Figures 5 and 6, each of these blocks 32a, 32b comprises:

[0080] - a first part 34 configured to cover a part of the internal surface 14a of the external shell 14 or of the external surface 12a of the internal shell 12,

[0081] - a second part 36 configured to cover a part of the intrados 16e or extrados 16f face of the arm 16, and

[0082] - a junction 38 between the first and second parts 34, 36 configured to extend at the level of the fillet 26 connecting the face part 16e, 16f with the surface part 12a, 14a.

[0083] The first part 34 of each block 32a, 32b is formed by a relatively flat wall in the example shown, insofar as it extends over the surface 12a, 14a of the ferrule 12, 14. The first part 34 of each block 32a, 32b comprises a free longitudinal edge 34a which is intended to extend along the aforementioned line L1 or L2. Each edge 34a is a tracing edge.

[0084] Figure 7a shows a Y axis passing through the end of the trailing edge 16d connected to the ferrule 12, 14, this Y axis being substantially perpendicular to the ferrule at the point of connection of the trailing edge 16d to this ferrule. The distance between this Y axis and the edge 34a of each block 32a, 32b is denoted D1 and is for example between 10 and 100mm, preferably between 20 and 50mm, and more preferably between 20 and 30mm (figure 7c).

[0085] The second part 36 of each block 32a, 32b is shaped to match the shape of the arm 16 and therefore of the intrados face 16a or extrados face 16b of the arm 16. The block 32a located on the side of the intrados face 16a therefore has a convex curved shape complementary to the concave curved shape of this face 16a. The block 32b located on the side of the extrados face 16b therefore has a concave curved shape complementary to the convex curved shape of this face 16b.

[0086] The second part 36 of each block 32a, 32b comprises a free longitudinal edge 36a which is intended to extend along the aforementioned line L3 or L4. Each edge 36a is a tracing edge.

[0087] The distance between the edge 36a of each block 32a, 32b and the ferrule 12, 14 is denoted D2 and is for example between 10 and 100mm, preferably between 20 and 50mm, and more preferably between 20 and 30mm.

[0088] Each of the blocks 32a, 32b may have a general L-shape insofar as the second part 36a may extend substantially perpendicular to the first part 34a.

[0089] Figure 8 shows that each of the blocks 32a, 32b may comprise projecting pads 40 configured to bear on the casing 10, the remainder of each of the blocks being configured to be set back relative to the casing to define a mounting clearance J of the or each control device 32. This mounting clearance makes it possible to compensate for any variations in the dimensions of the casing 10 due to manufacturing tolerances. In the example shown, the first part 34 of each block 32a, 32b comprises a pad 40 which extends along the edge 34a, over substantially its entire length. The second part 36 of each block 32a, 32b comprises a pad 42 which extends along the edge 36a, over substantially its entire length.Figures 4 to 6 also show that each of the blocks 32a, 32b comprises at least one portion 44a configured to be applied against a complementary portion 44b of the other of the blocks, so as to allow fixing or holding of the two blocks with respect to each other. The portions 44a, 44b can be fixed to each other or held together by fixing or clamping systems of the screw-nut type for example. Alternatively, magnets could be fixed or integrated into the portions 44a, 44b which would then be held together by cooperation of these magnets.

[0090] Alternatively, blocks 32a, 32b could be held together and in position solely by hand by the operator.

[0091] The control devices 32 of Figure 4 are all different in the example shown. They differ from each other because they are mounted on arms 16 of different shapes and on different ends of these arms. Two control devices (the two on the right in the drawing) are configured to be mounted around inner ends 16a of arms 16, and two other control devices (the two on the left in the drawing) are configured to be mounted around outer ends 16b of arms 16. To facilitate the distinction of the devices 32 by an operator who has to handle and use them, it would be possible to provide different colors between the devices or even for the blocks 32a, 32b of the same device. Furthermore, each of the blocks 32a, 32b may include an indication 50 of mounting on the inner or outer end of the arm 16, as illustrated in Figure 9.This indication 50 can be integrated into each block 32a, 32b and can for example be a protruding or hollow mention, such as in particular “out” and “in” with reference to the mounting on the external end 16b (“out” in English) or on the internal end 16a (“in” in English) of the arm 16.

[0092] Each of the blocks 32a, 32b is formed from a single piece in the example shown and is preferably produced by additive manufacturing. They are for example made of thermoplastic polyurethane.

[0093] We will now describe the method according to the invention for locating a mark on the casing 10.

[0094] This method comprises a step a) of visual inspection of the arms 16, of the external surface 12a of the internal shell 12, and of the internal surface 14a of the external shell 14.

[0095] Marks 46, 48 are schematically represented by stars in Figure 9. A mark 46 is located on the surface 14a of the ferrule 14 and another mark 48 is located on the intrados face 16e of the arm 16.

[0096] In the case where at least one mark 46, 48 is detected in step a) of the method, the method comprises: b) a step of manually mounting a visual control device 32 around the internal end 16a or external end 16b of one or more of the arms 16, and c) a step of determining the location of the or each mark 46, 48 in one of the aforementioned zones Z1, Z2, Z3 of the casing 10.

[0097] When a mark is hidden by the device 32 when it is present on the casing 10, it is understood that this mark is located in a zone Z1 of the casing 10.

[0098] When a mark is located on the surface 12a, 14a of the ferrule 12, 14 and is not hidden by the control device 32 in step b), it is understood that this mark is located in a zone Z2.

[0099] When a mark is located on the arm 16 and is not hidden by the control device 32 in step b), it is understood that this mark is located in a zone Z3.

[0100] Advantageously, to facilitate the location of the marks 46, 48, the method may comprise, between steps b) and c): i) a first intermediate step in which at least one line , Q., fà, etc. is drawn, for example with a felt-tip pen, on the arm 16 and / or the external surface 12a of the internal ferrule 12 and / or the internal surface 14a of the external ferrule 14, along the edges L1, L2, L3, L4 of the or each control device 32, as illustrated in FIG. 9, and ii) a second intermediate step in which the or each control device 32 is removed from the casing, and in which step c) is carried out as a function of the position of the or each mark 46, 48 relative to the or each drawn line c\ , <2, r3, etc. In the embodiment of figure 9, it can be seen that the marks 46, 48 are not located in the zone Z1, in particular because it is not hidden by the devices 32 and are not found between the lines fl, <2, fà, etc.after removal of the devices 32. The mark 46 is located on the surface 14a of the ferrule 14 and therefore in the zone Z2. The distance R1 between the mark 46 and the line (\ can be precisely measured by an operator by means of a ruler or a square, the measurement preferably being made in a direction perpendicular to the line c\ . The mark 48 is located on the intrados face 16e of the arm and therefore in the zone Z3 because it is not hidden by the devices 32 and is located on the arm 16. The distance R2 between the mark 46 and the line G> can be precisely measured by the operator by means of the ruler or the square, the measurement preferably being made in a direction perpendicular to the line G>.

[0101] In the case where the control device 32 of Figure 4 is used, it is understood that, in step b), a first control device 32 is mounted around an inner end 16a of a first arm 16, and a second control device 32 is mounted around an inner end 16a of a second adjacent arm 16, as illustrated in Figures 6 and 7a-7c. It is also understood that during the same step, a third control device 32 is mounted around an outer end 16b of the first arm 16, and a fourth control device 32 is mounted around an outer end 16b of the second adjacent arm 16, as illustrated in Figure 5. The tooling 30 and the method according to the invention allow in particular:

[0102] - to simplify control by operators; they will no longer have to worry about how to take measurements; in fact, with the tool 30, the operator can draw lines and measure the positions of the marks 46, 48 in relation to these lines;

[0103] - to guarantee that the requested control will be compliant and identical for all operators; - to avoid errors;

[0104] - to make the requested control more visual, etc.

Claims

DEMANDS 1. A method for locating a mark (46, 48) on a turbomachine (1) housing (10) of an aircraft, said housing (10) comprising two coaxial annular ferrules, respectively internal (12) and external (14), and arms (16) extending between the ferrules (12, 14) and each comprising an internal end (16a) connected to an external annular surface (12a) of the internal ferrule (12) and an external end (16b) connected to an internal annular surface (14a) of the external ferrule (14), characterized in that it comprises: a) a step of visually inspecting the arms (16), the external annular surface (12a) of the internal ferrule (12), and the internal annular surface (14a) of the external ferrule (14), and in the case where at least one mark (46, 48) is detected in step a), b) a step of manually mounting a visual control device (32) around the inner (16a) or outer (16b) end of one or more of the arms (16) on which said at least one mark (46,48) is detected, the control device or devices (32) being configured to cover a portion of the inner end (16a) of an arm (16) and a portion of the outer annular surface (12a) of the inner ferrule (12) extending around this inner end (16), or to cover a portion of the outer end (16b) of the arm (16) and a portion of the inner annular surface (14a) of the outer ferrule (14) extending around this outer end (16b), and c) a step of determining the location of said at least one mark (46, 48) in an area (Z1, Z2, Z3) of the housing (10):, - said at least one mark (46, 48) being located in a first zone (Z1) of the housing (10), which is a junction zone of one of the arms (16) to one of the ferrules (12, 14), when said at least one mark (46, 48) is hidden by the control device (32) in step b), - said at least one mark (46, 48) being located in a second zone (Z2) of the housing (10), which is a zone of an arm (16) excluded from the junction zones of that arm, when said at least one mark (46, 48) is located on the annular surface (12a, 14a) of the ferrule (12, 14) and is not hidden by the control device (32) in step b), and - said at least one mark (46, 48) being located in a third zone (Z3) of the housing (10), which is a zone of the housing excluded from the arm junction zones, when said at least one mark (46, 48) is located on the arm (16) and is not hidden by the control device (32) in step b).

2. A method according to claim 1, wherein it comprises, between steps b) and c): i) a first intermediate step in which at least one line (d, Q., fà, ) is drawn on the arm (16) and / or the outer annular surface (12a) of the inner ferrule (12) and / or the inner annular surface (14a) of the outer ferrule (14), along edges (32a, 34a) of the or each control device (32), and ii) a second intermediate step in which the or each control device (32) is removed from the housing (10), and in which step c) is carried out according to the position of said at least one mark (46, 48) with respect to the or each line (d, Q., fà, ) drawn.

3. Method according to claim 2, wherein said at least one line (d , <2, r3, ) is drawn with a felt-tip pen.

4. A method according to any one of the preceding claims, wherein, in step b): - a first control device (32) is mounted around an inner end (16a) of a first arm (16) on which said at least one mark (46, 48) is detected, and a second control device (32) is mounted around an inner end (16a) of an adjacent second arm (16) on which said at least one mark (46, 48) is detected.

5. A method according to claim 4, wherein, in step b): - a third control device (32) is mounted around an outer end (16b) of the first arm (16) on which said at least one mark (46, 48) is detected, and a fourth control device (32) is mounted around an outer end (16b) of the second adjacent arm (16) on which said at least one mark (46, 48) is detected.

6. A method according to any one of the preceding claims, wherein, the control device or each control device (32) comprising two blocks (32a, 32b), step b) comprises positioning the two blocks (32a, 32b) on either side of the arm (16).

7. Method according to claim 6, wherein the two blocks (32a, 32b) are fixed or held together.

8. Tooling for implementing a method according to any one of the preceding claims, the tooling comprising at least one visual inspection device (32) configured to be mounted around an external (16b) or internal (16a) end of an arm (16) of the housing (10), the inspection device(s) (32) comprising two blocks (32a, 32b) configured to be mounted on either side of the arm (16), each of these blocks (32a, 32b) comprising: - a first part (34) configured to cover a part of the internal annular surface (14a) of the external ferrule (14) or of the external annular surface (12a) of the internal ferrule (12), - a second part (36) configured to cover part of an intrados (16e) or extrados (16f) face of the arm (16), and - a junction (38) between the first and second parts (34, 36) configured to extend at the level of a fillet (26) connecting the front part (16e, 16f) with the annular surface part (12a, 14a).

9. Tooling according to claim 8, wherein each of the blocks (32a, 32b) has a general L-shape.

10. Tooling according to claim 8 or 9, wherein each of the blocks (32a, 32b) comprises projecting pads (40) configured to bear against the housing (10), the remainder of each of the blocks (32a, 32b) being configured to be set back from the housing (10) to define a mounting clearance (J) of the or each control device (32).

11. Tooling according to any one of claims 8 to 10, wherein each of the blocks (32a, 32b) comprises a longitudinal edge (34a, 36a) configured to form a tracing reference.

12. Tooling according to any one of claims 8 to 11, wherein each of the blocks (32a, 32b) comprises at least one portion (44a, 44b) configured to be applied against a complementary portion (44b, 44a) of the other of the blocks, so as to allow fixing or holding of the two blocks (32a, 32b) to each other.

13. Tooling according to any one of claims 8 to 12, wherein each of the blocks (32a, 32b) includes a mounting indication (50) on the inner (16a) or outer (16b) end of the arm.

14. Tooling according to any one of claims 8 to 13, wherein it comprises at least two independent control devices (32) configured to be mounted around internal ends (16a) of arms (16), and two other independent control devices (32) configured to be mounted around external ends (16b) of arms (16).

15. Tooling according to claim 14, wherein the control devices (32) are all different.

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