Machining device and method for repairing an annular workpiece

Abstract

The invention relates to a machining device (10) for machining an annular workpiece (100; 110), in particular a turbomachine, characterized in that the machining device comprises: - a fastening system (50) for releasably fastening the machining device to the workpiece; - a machining tool (20) for machining at least one region of the workpiece to be machined; - a carriage (30) for transporting the machining tool; and - a rail (40) which is shaped such that it guides the transport carriage displaceably along the region of the workpiece to be machined.

Description

TECHNICAL FIELD

[0001] The technical field of the invention is the repair of workpieces for turbomachines in aircraft.

[0002] The present invention relates to a device for machining an annular workpiece, in particular for a turbomachine, and a method for repairing such a workpiece. STATE OF THE ART

[0003] Turbomachinery includes various workpieces that, after use, may exhibit damaged or worn areas or zones due to friction or erosion caused by the penetration of particles entrained by one or more air streams passing through the turbomachinery, or by impact from foreign objects. These defective, damaged, or worn workpieces exhibit profile changes that impair the performance of both the workpiece and the turbomachinery. In the worst case, these workpieces can fracture, which can lead to significant damage to the turbomachinery.

[0004] When repairing components for aircraft turbomachines, accessibility issues often arise. For example, these problems exist with the annular flange between the engine and the inverter of a turbomachine, for which no repair solution is currently available. In the event of excessive wear, this annular flange is completely replaced, requiring disassembly of the turbomachine to remove and replace the defective annular flange.

[0005] An aircraft is powered by several propulsion units, each of which is suspended from a fixed structure of the aircraft, for example under a wing or on the fuselage of the aircraft, via a suspension pylon. Fig. 1 shows such a propulsion unit 1, which, as is known, comprises a turbojet engine 2 equipped with a fan or impeller and an engine and a nacelle 3 surrounding the turbojet engine and accommodating a thrust reverser.

[0006] The nacelle 3 generally has a tubular structure comprising an upstream section or air inlet 4 upstream of the turbojet engine 2, a central section 5 surrounding the turbojet fan, a downstream section 6 housing the thrust reverser and surrounding a combustion chamber and the turbojet turbines carrying the thrust reversers, and generally terminating in an exhaust nozzle whose outlet is downstream of the turbojet engine 2.

[0007] The downstream section 6 generally comprises an external structure comprising an outer cover 7 which, together with a concentric internal structure (in Fig. 1 not visible), called the "Inner Fixed Structure" (IFS), defines the annular channel used to channel the cold air flow. The inner structure defines an inner portion of the annular core and generally consists of two half-shells connected at six o'clock by means of a locking device.

[0008] The thrust reverser system allows the braking performance of an aircraft to be improved during landing by redirecting most of the thrust generated by the turbojet engine forward.

[0009] The external fixed structure of a thrust reverser comprises, in a known manner, a peripheral forward frame to be attached to a fan casing of the corresponding turbojet engine, a peripheral rear frame, and a plurality of flow deflection grids mounted between the forward and rear frames and extending substantially parallel to the geometric longitudinal axis of the thrust reversers. The forward and rear frames are arranged transversely to the geometric longitudinal axis of the thrust reversers.

[0010] The front frame is connected to the fan casing by fasteners that are generally of the blade / throat type and include a substantially annular flange, also called a ring flange, that is attached to the front frame in one or more parts and cooperates with a J- or V-shaped groove. Both the fastener and the annular flange, which has a J- (or V-) shaped cross-section, are commonly referred to as a J-ring.

[0011] There have been many cases of wear on annular flanges of this type due to friction between the annular flanges and the corresponding grooves in the fasteners. Excessive wear in this area leads to problems at the interfaces such as play and vibration...

[0012] Replacing this annular flange, usually made of aluminum, is a complex, time-consuming, and therefore costly operation. Indeed, this process requires dismantling the nacelle and many of its components and transporting them to a repair shop.

[0013] It would therefore be advantageous to find an alternative to replacing this component that allows for repair under the wing, i.e. with the component installed in the turbomachine, and ensures rapid release of the aircraft.

[0014] A dynamic spray repair process, also known as "cold spray" or "reloading," can be performed using a direct jet nozzle that sprays metal powder at very high velocity, which can fill damage to the surface of worn workpieces.

[0015] However, such a repair process results in a deformed surface after refilling.

[0016] Fig. Figure 2 shows a cross-section of the geometry of a J-ring-shaped annular flange 110 and a zone Z of this annular flange 110 to be repaired. It is evident that the space for inserting a machining tool is limited. Therefore, there is currently no machining fixture that can be inserted into this architecture without affecting other components adjacent to the annular flange 110. In other words, the geometry of the annular flange or "J-ring"-type annular flange 110 makes the use of a conventional machining fixture impossible, especially if the annular flange remains installed in the aircraft.

[0017] The object of the present invention is therefore to propose a device for machining an annular workpiece, such as a J-ring type annular flange, which can restore and control the original profile of the workpiece while overcoming at least some of these disadvantages. SUMMARY OF THE INVENTION

[0018] For this purpose, the invention relates to a device for machining an annular workpiece, in particular for a turbomachine, characterized in that the machining device comprises: - a fastening system for releasably attaching the machining device to the workpiece; - a machining tool for machining at least one zone of the workpiece to be machined; - a carriage for transporting the machining tool; and - a rail shaped to guide the carriage slidably along the zone of the workpiece to be machined, the rail being flat and in the shape of a circular arc.

[0019] The invention thus provides a solution to the above-mentioned problems and makes it possible to overcome the above-mentioned problems of accessibility and size in order to repair, under the wing, a "J-ring" type workpiece or any other turbomachinery workpiece whose geometry does not allow the use of a conventional machining device.

[0020] Thanks to the invention, it is possible to position the machining device according to the invention so that the machining tool can easily reach the surface of the workpiece to be repaired, despite the geometry of the workpiece and the limited accessibility to the area to be repaired. The machining device according to the invention thus enables the repair of the annular workpiece, for example, an annular flange of a turbomachine, by restoring the original profile and properties of the workpiece while the workpiece remains installed in the turbomachine, which in turn is located under the wing of the aircraft. This eliminates the need to dismantle the aircraft's turbomachine, allowing the aircraft to be released more quickly than before.The machining device according to the invention can also be used to repair the annular flange on components removed from the turbomachine, for example in a workshop.

[0021] Such a machining device according to the invention has the advantage that it can be easily transported to the aircraft location where such a ring-shaped workpiece to be repaired is located. It is therefore not necessary to dismantle the nacelle and transport it to a repair shop. This allows the machining device to be deployed quickly. In the case of a repair in a workshop, there is no need to transport the equipment, and the process can be performed in any workshop if necessary. It also has the advantage of being attached directly to the part to be repaired, allowing it to be easily restored to its original surface profile.

[0022] The processing device according to the invention may have one or more of the following features, which may be combined individually or in any technically possible combination: - The machining device also includes a system for moving the transport carriage on the rail along the zone of the workpiece to be machined. - The movement system comprises a drive element for moving the transport carriage on the rail, preferably a rack and pinion drive element; - The system for moving the transport carriage on the rail includes a manual or electric feed system; - The transport carriage comprises a plate running parallel to the rail and at least three rollers arranged on the plate, wherein at least two of the rollers are designed to cooperate with a first guide track of the rail and at least one of the rollers is designed to cooperate with a second guide track of the rail, wherein the two guide tracks are each arranged on an inner peripheral edge of the rail and an outer peripheral edge of the rail; - The rail is arranged between at least one radially outer roller and one radially inner roller; - Each roller has a groove designed to receive one of the guideways of the rail, the groove preferably having a V-shaped cross-section and the guideways having a complementary shape; - Each guideway of the rail has a groove designed to receive one of the rollers, the groove preferably having a V-shaped cross-section and each roller having at its peripheral end a projection shaped complementarily to the groove; - the plate and the machining tool are arranged on both sides of the rail, in particular in the plane of the rail, when the transport carriage is arranged on the rail; - The movement system and the machining tool are arranged on both sides of the rail; - The machining device comprises a tool for geometric control of the zone of the workpiece to be machined, wherein the transport carriage is designed to receive the tool for geometric control; - The fastening system designed to fasten the machining device to the workpiece comprises at least one workpiece fastening flange, preferably two workpiece fastening flanges, each arranged at one end of the rail to hold the rail in its position relative to the workpiece; - Each mounting flange is shaped to hold the rail in position relative to the workpiece in an axial direction parallel to the axis of rotation of the annular workpiece; - The fastening system comprises at least one additional fastening element, preferably two additional fastening elements, each arranged at one end of the rail, wherein the additional fastening element or elements are designed to fasten the rail to a frame supporting the workpiece; - Each additional fastening element is shaped to hold the rail in position with respect to the workpiece in a radial direction perpendicular to the axis of rotation of the annular workpiece; - Each additional fastening element comprises two mutually perpendicular arms: a first arm extending radially outward from a first end fastened to the rail and having a second end opposite the first end, and a second arm perpendicular to the first arm and having a first end connected to the second end of the first arm and a second end opposite the first end of the second arm and comprising means for attachment to the frame. - The transport carriage has a system for positioning the machining tool relative to a zone of the workpiece to be machined.

[0023] The invention also relates to a method for repairing an annular flange of a turbomachine, the annular flange having a damaged zone, the repair method comprising the following steps: - a step of refilling material into the damaged zone of the ring flange to form a refilled zone of the ring flange; - a step of machining the replenished zone of the annular flange to obtain a repaired zone of the annular flange, this step being carried out by a machining device according to any one of the preceding claims.

[0024] The processing method according to the invention may comprise one or more of the following features, which may be combined individually or in any technically possible combination: - The annular flange or ring flange is installed on a turbomachine during the repair process; - The method comprises a step of moving the machining device relative to the refilled zone of the annular flange and a step of fixing the rail to at least the annular flange; - The method comprises a step of moving the carriage for transporting the machining tool relative to the refilled zone of the annular flange; - The method comprises a step of positioning the machining tool so that the replenished zone of the ring flange is machined to obtain a repaired zone of the ring flange. SHORT DESCRIPTION OF THE CHARACTERS

[0025] The invention will be better understood and further details, features and advantages of the present invention will become clearer from the following description, which serves as a non-limiting example, and with reference to the attached drawings, in which: Fig. 1 already described, a schematic three-dimensional view of a drive assembly with an annular workpiece that may require repair; Fig. 2 already described, a profile view of an annular flange with a damaged zone that needs to be repaired; Fig. 3 schematically shows a processing device according to an example of the invention; Fig. 4 a perspective view of the Fig. 3 shown processing device in its functional position; Fig. 5 a cross-sectional view of the Fig. 3 shown processing device in its functional position; Fig. 6 an enlarged view of Fig. 5 at the level of the machining tool; Fig. 7 is a view of the cutting tool of the machining device of Fig. 3 in the functional position for repairing a J-ring type annular flange; Fig. 8 the end of a J-ring type annular flange in its initial condition before wear; Fig. 9 shows the end of the annular flange of the “J-Ring” type from Fig. 8 with a worn zone; Fig. 10 the result of a refill step on the worn zone of the end of the Fig. 9 shown ring flange of type “J-Ring”; and Fig. 11 shows the result of a machining step carried out by the machining device according to the invention on the refilled zone of the end of the annular flange of the “J-Ring” type in Fig. 10 was carried out.

[0026] The elements with the same functions in the different embodiments have the same reference numerals in the figures.

[0027] In the description and in the claims, the terms “upstream” and “downstream” are defined with reference to the air flow within the propulsion assembly formed by the nacelle and the turbojet engine, that is to say from left to right, with reference to Fig. 1. Likewise, the terms "inside" or "inside" and "outside" or "outside" are used without limitation to refer to the radial distance from the longitudinal axis of the nacelle, with the term "inside" defining a region that, in contrast to the term "outside," is radially closer to the longitudinal axis of the nacelle. For the purpose of clarifying the description and claims, the terms "axial," "radial," and "transverse" are used with reference to the triangle A, R, T shown in the figures. DESCRIPTION OF EMBODIMENTS

[0028] It will be Fig. 3, which shows a processing device according to an embodiment of the invention, as well as to the Fig. 4 to 7, the views of the device from Fig. 3 in its functional position, ie arranged so that it can machine an annular workpiece 100, in particular for a turbomachine.

[0029] As already mentioned, such a turbomachine includes ring-shaped workpieces where hard-to-reach damaged areas need to be repaired.

[0030] In particular, a thrust reverser comprises means for attaching the front frame to the turbomachine, which, due to their J- or V-shape, have an annular flange of the J-ring type.

[0031] In the Fig. In the example shown in Figures 4 to 7, the annular workpiece 100 is an annular flange 110 of the J-ring type of the thrust reverser.

[0032] Such an annular flange 110 is also in Fig. 8 and includes a J- or V-shaped bent or curved end 112 having a surface S that is subject to wear during use. As a result, the surface may have a damaged zone, as shown in Fig. 9. From the Fig. 8 and Fig. 9, it can be seen that the annular flange to be machined comprises an annular body extending axially between a first end and a second end. The axial direction is the direction parallel to the axis of symmetry of the annular flange, which generally coincides with the longitudinal axis of the turbomachine module or the turbomachine itself to which the annular flange is attached. As already indicated, one of the ends is bent or curved into a J-shape or a V-shape. In other words, the annular flange comprises a rim extending at least radially from the body, and more precisely from the first end of the body to a third end, to give the end 112 of the annular flange a folded or bent J-shape. The rim may further extend both radially and towards the second end to give the end 112 of the annular flange a folded or bent V-shape.The rim thus extends between the first end of the body and the third end. The rim has a first surface and a second surface, with the second surface being closer to the second end of the body of the annular flange. This second surface comprises a zone Z to be machined and / or repaired, which is difficult to access with prior art machining devices.

[0033] The machining device according to the invention is suitable for repairing workpieces made of an aluminum alloy, titanium or other metallic materials.

[0034] Fig. Figure 3 schematically shows an example of a device 10 for machining an annular workpiece according to the invention. The annular workpiece is rotationally symmetrical about a rotation axis.

[0035] Such a processing device 10 comprises: - a machining tool 20 for machining at least one zone of the workpiece to be machined; - a carriage 30 for transporting the machining tool 20; and - a rail 40 designed to guide the transport carriage 30 along the zone of the workpiece to be machined.

[0036] The machining tool 20 is a tool such as a drill, a pneumatic or electric drill, a milling cutter or a grinding wheel, which is selected according to the zone of the workpiece to be machined.

[0037] The machining device 10 comprises a fastening system 50 for releasably fastening the machining device to the workpiece, in this case to the annular flange 110.

[0038] Advantageously, the fastening system 50 comprises at least one flange 52 for fastening to the workpiece 100 in order to hold the rail in position relative to the workpiece in an axial direction A parallel to the rotation axis of the annular workpiece. In the Fig. 3 and Fig. In the example shown in Figure 4, such a mounting flange 52 comprises a substantially flat plate extending in a plane substantially perpendicular to the rail 40 of the machining device. The plate is secured to the workpiece and to the rail 40 by fastening means, such as screw / nut systems.

[0039] Preferably, the fastening system 50 comprises two flanges 52 for fastening to the workpiece, each arranged at one end of the rail 40.

[0040] Advantageously, the fastening system 50 comprises at least one additional fastening element 54 for fastening the rail to a frame 120 supporting the workpiece. In the case of the annular flange 110, the additional fastening element 54 enables the fastening of the positioning system to the frame supporting the annular flange 110 and thus ensures its positioning in a so-called radial direction R perpendicular to the axis of rotation of the annular workpiece. For this purpose, the additional fastening element 54 comprises, in the Fig. 3 and Fig. 4 shows two arms running perpendicular to each other: - a first arm extending radially outward from a first end secured to the rail 40, in particular to an outer edge 44 of the rail 40, and having a second end opposite the first end, and - a second arm perpendicular to the first arm and having a first end connected to the second end of the first arm and a second end opposite the first end of the second arm and having means for attachment to the frame 120, for example a screw / nut system.

[0041] Advantageously, the second arm can be connected to the first arm by a radial-axis sliding connection, thereby facilitating the attachment of the machining device to the frame 120, in particular by adapting the additional fastening element to the dimensions of the frame. For this purpose, the first arm can also be moved along the rail.

[0042] Preferably, the fastening system comprises two additional fastening elements 54, each arranged at one end of the rail 40 and designed as described above.

[0043] For example, the mounting flange(s) 52 and the additional fastening element(s) 54 are clamped to the annular workpiece or the frame.

[0044] The rail 40 has a circular or arcuate shape with a radius substantially corresponding to that of the annular workpiece, allowing it to be applied to the workpiece. Thus, after the machining device has been set up and secured to the annular workpiece, the geometric center of the circular arc forming the rail 40 is aligned with the rotational axis of the annular workpiece.

[0045] The rail 40 extends over an angular range between 60° and 180°. Preferably, the rail 40 extends over an angular range of 60°, allowing, for example, half of the ring-shaped workpiece to be covered by moving the rail only three times. The size of the rail allows for easy transport and use anywhere in the world where the equipment is located.

[0046] The rail 40 extends between a first end 41 and a second end 42 opposite the first end 41.

[0047] In the Fig. In the embodiment shown in Figures 3 to 7, the rail 40 extends radially between an inner peripheral edge 43 and the outer peripheral edge 44. The inner 43 and outer 44 edges of the rail define a principal plane perpendicular to the rotational axis of the annular workpiece when the machining device is installed and secured to the annular workpiece. A principal rail axis is defined as an axis perpendicular to the principal plane of the rail and passing through its geometric center. Thus, when the machining device is attached and secured to the annular workpiece, the principal axis of the rail and the rotational axis of the annular workpiece to be machined are congruent. Fig. In particular, it is clear from Figures 3 to 5 that the rail 40 is flat, as it lies in the main plane and has a circular arc shape in this plane, more precisely a circular ring gear shape. In this main plane, the rail 40 extends between two sections of concentric circles with different radii, namely the inner peripheral edge 43 and the outer peripheral edge 44.

[0048] The transport carriage 30 has a plate 32 or a holder which is designed to hold the machining tool 20.

[0049] Advantageously, the transport carriage 30 comprises a positioning system 33 held by the plate 32. The positioning system 33 is designed to position the machining tool 20 with high precision in three mutually perpendicular directions relative to the area(s) of the workpiece to be machined. The positioning system 33 comprises adjustment means, such as micrometer screws, and means for locking the machining tool 20 in its position relative to the area to be machined.

[0050] In the illustrated embodiment, when the transport carriage is arranged on the rail 40, the plate 32 extends in a plane parallel to the main plane of the rail, ie in a plane transverse to the main axis of the rail.

[0051] The plate 32 and the machining tool 20 are arranged on both sides of the rail, in particular the main plane of the rail, when the transport carriage is arranged on the rail 40, so that the machining tool 20 has access to the surface of the annular workpiece to be machined when the machining device is installed and fixed to the annular workpiece.

[0052] The transport carriage 30 is movable on the rail 40. Advantageously, the machining device 10 comprises a system 60 for moving the transport carriage 30 on the rail 40 along the zone of the workpiece to be machined.

[0053] Advantageously, the movement system 60 comprises a drive element 62 for moving the transport carriage 30 on the rail 40.

[0054] In the example of the Fig. In the processing device 10 shown in Figures 3 to 7, the drive element 62 is, for example, a rack and pinion drive element.

[0055] In the example shown, the drive element 62 thus comprises a rack arranged on the rail 40 and a gear 66 arranged on the plate 32 of the transport carriage 30, which cooperates with the rack of the rail by engaging the teeth of the rack. The gear 66 extends parallel to the plate 30.

[0056] Preferably, the movement system 60, in particular the gear of the drive element, and the machining tool 20 are arranged on either side of the rail 40. More specifically, the machining tool 20 is arranged closer to the main axis of the rail than the movement system in order to minimize the size of the machining device and ensure access of the machining tool to the area to be machined, as well as to balance the masses of the various elements of the machining device and thus ensure optimal movement.

[0057] The movement system 60 of the transport carriage on the rail includes a feed system on the rail 40. In the example shown, the feed system is manual and includes a crank 68 configured to rotate the gear 66 of the drive element.

[0058] Alternatively, the feed system may be electric and include an electric motor configured to rotate the gear 66 of the drive member.

[0059] Advantageously, the transport carriage 30 has at least three rollers arranged on the plate 32. The rollers, generally designated 34, are each rotatable about a rotation axis perpendicular to the plate 32. At least two of the rollers are designed to interact with a guide track 45 of the rail, and at least one of the rollers is designed to interact with another guide track 46 of the rail. The two guide tracks 45, 46 are arranged on the inner edge 43 and the outer edge 44 of the rail, respectively.

[0060] In the example shown in the figures, four rollers 34A, 34B, 34C, and 34D are supported by the plate of the transport carriage. Rollers 34A and 34B are arranged radially outward with respect to rail 40, while rollers 34C and 34D are arranged radially inward with respect to rail 40. In other words, rail 40 is arranged between the pair of radially outer rollers 34A, 34B and the pair of radially inner rollers.

[0061] Fig. Figure 5 shows a sectional view of the processing device in its functional position in the sectional plane through the rotation axes of the rollers 34B and 34D.

[0062] In the example shown, each roller has a groove 35 designed to receive one of the guideways 45, 46 of the rail, as shown in the sectional view in Fig. 4. In the example shown, the groove has a V-shaped cross-section, and the guideways 45, 46 have a complementary triangular shape. However, there are also other shapes for the groove and thus for the complementary shape of the guideway.

[0063] Alternatively, each guideway may have a groove and each roller may have a projection at its circumferential end whose shape is complementary to that of the groove.

[0064] Advantageously, the machining device 10 may include a geometric control tool (not shown) configured to control the geometric profile of the machined / machinable surface of the machinable zone of the workpiece. In this case, the transport carriage 30 is configured to support the geometric control tool.

[0065] The geometric control tool is, for example, a mechanical or electronic micrometer, possibly with a system for recording the position of the zone to be machined and the profile of the surface before and after machining.

[0066] We now describe a method for repairing a turbomachine annular flange, for example of the "J-ring" type. The annular flange 110 includes a J- or V-shaped bent or curved end 112 with a surface S that is subject to wear during use. The front annular flange prior to use is in Fig. 8 and has an initial surface profile marked “Si”.

[0067] After use, the annular flange has worn / damaged areas as shown in Fig. 9, with a loss of material compared to the original profile. Such a damaged area Z has a surface profile labeled "Su" and must be repaired.

[0068] The repair process includes a step of refilling material into the damaged zone of the annular flange to create a refilled zone Zr of the adapter ring with a material gain compared to the Fig. 9 to form the damaged zone shown.

[0069] During this refilling phase, the damaged zone Z is coated with metal powder by a dynamic spraying device suitable for refilling the zone.

[0070] Advantageously, this step can be performed without removing the annular flange, i.e., while the annular flange is installed on the turbomachine using a dynamic gas spray device, as described in patent application FR 2 209 900. This eliminates the need to disassemble the unit, resulting in significant time savings.

[0071] Fig. Figure 10 shows the result of this step. The damaged zone with a surface profile “Su” ( Fig. 9) was refilled to form a refilled zone Zr with a surface profile “Sr”.

[0072] To restore the original surface profile "Si", the refilled zone is machined in a machining step performed with a machining device according to the invention and as described above. For this purpose, the machining device is attached to the workpiece opposite the zone to be machined by means of the attachment 50, and the machining tool 20 is moved along the rail to position it opposite the zone to be machined.

[0073] The result of this step is in Fig. 11 schematically. The refilled zone Zr with a surface profile “Sr” ( Fig. 10) was edited to create the original profile “Si” from Fig. 8 to restore.

[0074] Advantageously, this step can also be performed without removing the ring flange, i.e., while the ring flange is installed on the turbomachine. This eliminates the need to disassemble the unit, resulting in significant time savings.

[0075] The position of the transport carriage 30 and / or that of the machining tool 20 are changed as often as necessary to repair all damaged zones of the ring flange that are accessible with the tool in this position of the machining device relative to the ring flange.

[0076] The machining device is then moved again and fixed relative to another section of the ring flange, which includes areas to be machined again, in order to cover this other section of the ring flange which is accessible to the machining tool.

[0077] In particular, the machining device is positioned and the rail of the machining device is fixed by the rail at least to the ring flange and preferably also to the frame supporting the ring flange.

[0078] In the event that the machining device comprises at least one flange 52 for fastening to the workpiece 100, preferably two, in order to hold the rail in position relative to the workpiece in the axial direction A parallel to the axis of rotation of the annular workpiece, the machining step advantageously comprises a step for positioning the machining device opposite the refilled zone of the annular flange, followed by a step for fastening the rail to the flange. In particular, the rail 40 is fastened to the annular flange 110 via at least one plate. The plate(s) is (are) fastened to the workpiece 110 and to at least one end of the rail 40, preferably to each end of the rail 40, by fastening means such as screw / nut systems, as shown in the Fig.3 to 5. In the preferred case where the fastening system 50 comprises two flanges 52 for fastening to the workpiece, these are each arranged at a separate end of the rail 40.

[0079] In the event that the machining device also comprises at least one additional fastening element 54 for fastening the rail 40 to a frame 120 supporting the workpiece, the machining step advantageously also comprises a step for fastening the rail 40 to such a frame 120 to ensure its positioning in the radial direction R perpendicular to the axis of rotation of the annular workpiece. In this case and in the example shown, every other arm of the additional fastening elements 54 is fastened to the frame 120 supporting the workpiece 100 by fastening means, for example a screw / nut system.

[0080] In this way, the additional fastening element(s) 54 enable the positioning system to be fastened to the frame supporting the annular flange 110, thus ensuring its positioning in a so-called radial direction R perpendicular to the rotation axis of the annular part. In the preferred case in which the fastening system 50 comprises two additional fastening elements 54, these are each arranged at a different end of the rail 40.

[0081] For example, the mounting flange(s) 52 and the additional fastening element(s) 54 are clamped to the annular workpiece or to the frame.

[0082] According to the embodiment of the machining device in which it comprises a system 60 for moving the transport carriage along the rail, the machining step comprises, after the step of securing the machining device to the workpiece to be machined and, if appropriate, also to the frame supporting the workpiece, a step of displacing the transport carriage 30 of the machining tool 20 by means of the movement system in order to position it opposite the refilled zone of the annular flange 110. Its position is then advantageously locked to the rail by a locking device on the transport carriage. In this way, the machining tool 20 is initially positioned opposite the area to be machined by the movement of the transport carriage 30 carrying it along the rail by means of the movement system 60, as previously described.

[0083] Advantageously, the transport carriage is driven in its movement by the drive element 62 of the movement system 60, for example by a rack / gear system.

[0084] In the event that the movement system 60 advantageously also comprises a system for moving forward on the rail 40, the transport carriage 30 can be easily moved along the rail manually by means of the crank 68 connected to the gear or electrically by means of a motor for driving the gear 66.

[0085] The machining tool 20 is then positioned with great precision in three mutually perpendicular directions with respect to the refilled zone of the annular flange of the workpiece to be machined by the positioning system 33 carried by the plate 32 of the transport carriage 30 in order to obtain a repaired area of ​​the annular flange.

[0086] The plate 32 and the machining tool 20 are arranged on both sides of the rail, in particular the main plane of the rail, when the transport carriage is arranged on the rail 40, so that the machining tool 20 has access to the surface of the annular workpiece to be machined when the machining device is installed and fixed to the annular workpiece.

[0087] Their position is preferably locked before machining of the zone begins by means of a system for locking the position of the machining tool.

[0088] In addition, the method can advantageously comprise a control step in which the geometric profile of the surface of the area of ​​the workpiece to be machined or of the machined area of ​​the workpiece is checked using a geometric control tool carried by the transport carriage 30.

[0089] It should be noted that the examples shown in the figures are by no means limiting; the repair procedure for an annular flange described above can be adapted to any other component whose shape and arrangement in a turbomachine does not allow machining under the wing, i.e. when the workpiece remains installed in the turbomachine.

[0090] The machining device is suitable for machining all types of ring-shaped parts made of aluminum alloys, titanium or other metallic materials.

[0091] The advantage of this type of machining device according to the invention is that it can be easily transported to the location where the annular part to be repaired is to be installed. This eliminates the need to disassemble the gondola and transport it to a repair shop. This allows the machining device to be deployed quickly. It also has the advantage of being attached directly to the workpiece to be reworked, allowing it to easily regain its original surface profile. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] FR 2 209 900

[0070]

Claims

[1] Device (10) for machining an annular workpiece (100; 110), in particular for a turbomachine, characterized by that the processing device has: - a fastening system (50) for releasably fastening the machining device to the workpiece; - a machining tool (20) for machining at least one zone of the workpiece to be machined; - a carriage (30) for transporting the machining tool; and - a rail (40) shaped to guide the transport carriage slidably along the zone of the workpiece to be machined, the rail being flat and having the shape of a circular arc. [2] Machining device according to claim 1, further comprising a system (60) for moving the transport carriage (30) on the rail (40) along the zone of the workpiece to be machined. [3] Processing device according to claim 2, wherein the movement system (60) comprises a drive element (62) for moving the transport carriage (30) on the rail (40), preferably a rack and pinion drive element. [4] Machining device according to claim 2 or 3, wherein the system (60) for moving the transport carriage on the rail comprises a manual or electric feed system. [5] Processing device according to one of claims 1 to 4, wherein the transport carriage (30) has a plate (32) running parallel to the rail (40) and at least three rollers (34a, 34b, 34c, 34d) arranged on the plate, wherein at least two of the rollers are configured to cooperate with a first guide track (45) of the rail, and at least one of the rollers is configured to cooperate with a second guide track (46) of the rail, wherein the two guide tracks are each arranged on an inner peripheral edge (43) of the rail and an outer peripheral edge (44) of the rail. [6] Machining device according to one of the preceding claims, comprising a tool for geometric control of the zone of the workpiece to be machined, wherein the transport carriage (30) is designed to receive the tool for geometric control. [7] Machining device according to one of the preceding claims, wherein the fastening system (50) designed to fasten the machining device to the workpiece comprises at least one workpiece fastening flange (52), preferably two workpiece fastening flanges, each arranged at one end of the rail (40) to hold the rail in its position relative to the workpiece. [8] Machining device according to one of the preceding claims, wherein the fastening system (50) comprises at least one additional fastening element (54), preferably two additional fastening elements (54), each arranged at one end of the rail (40), wherein the additional fastening element or the additional fastening elements are designed to fasten the rail to a frame carrying the workpiece. [9] Machining device according to one of the preceding claims, wherein the transport carriage (30) comprises a system (33) for positioning the machining tool (20) relative to a zone of the workpiece to be machined. [10] A method for repairing an annular flange of a turbomachine, the annular flange having a damaged zone, the repair method comprising the following steps: - a step of refilling material into the damaged zone of the ring flange to form a refilled zone of the ring flange; - a step of machining the replenished zone of the annular flange to obtain a repaired zone of the annular flange, this step being carried out by a machining device according to any one of the preceding claims.

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