BRIDLING SYSTEM FOR A BLADE STEM

Abstract

The invention relates to a system for clamping a root (20) of a turbomachine blade (12), having a generally elongated shape, this system comprising: a vice (24) comprising two jaws (26, 28) provided with grips (30, 32) defining between them a space (34) configured to receive said root (20), at least one of the jaws (26) being movable, a first fixed element (36) comprising a first stop surface (38) perpendicular to an axis of elongation (A) of said space (34) and which is located at a first longitudinal end (40) of said space (34), and a second movable element (42), located at a second longitudinal end (44) opposite said space (34), movable between a first position in which it leaves said second end (44) open and a second position in which it closes said second end (44), this second element (42) comprising a second stop surface (46). Figure for abstract: Figure 1

Description

Title of the invention: SYSTEM FOR BLOCKING A BLADE FOOT Technical field of the invention

[0001] The invention relates to a system for clamping a blade root, in particular for the purpose of marking it, and a method for marking this root using said system. Technical background

[0002] The marking of turbomachine blades in the context of mass production is an essential requirement due to the need to be able to ensure traceability of the blades throughout their life cycle. The marking makes it possible both to identify the blades prior to their assembly in the compressor or turbine rotor discs for which they are intended, and to ensure monitoring of their characteristics, such as for example their manufacturing date, or the production sites in which they were produced in the event of maintenance or failure. In the latter case in particular, the marking is of capital importance because it helps to determine whether the failure is accidental or whether it could potentially result from a manufacturing defect occurring in the same batch of blades.

[0003] A blade generally comprises a blade of general radial orientation comprising at its proximal end a platform below which extends a root of elongated shape forming a root of substantially constant section oriented in a direction substantially perpendicular to the radial direction of the blade, which is intended to be received in a notch of the disk of the same direction and of section substantially complementary to the sides of the root.

[0004] The marking is generally carried out under a lower face of the root which is located at the junction of the sides of the root, because this lower face, once the root is mounted in the rotor or compressor disk, is protected from most of the attacks to which the blade is subjected during its use.

[0005] To do this, the blade must be immobilized so as to leave this lower face visible. The foot is generally introduced into an elongated receiving space delimited between the two jaws of a vice, leaving the lower face visible, then it is clamped between these jaws. To immobilize the foot before clamping and to guarantee a clear position of the foot between the jaws, it must be immobilized in the general direction of the jaws in order to prevent it from slipping between them.

[0006] However, there are a large number of solutions for immobilizing the foot. Until now, each of them has been developed in a manner specific to the dawn which is to be marked, and there is no blade clamping system that can quickly adapt to several references.

[0007] There is therefore a real need for a system for clamping a turbomachine blade root that can be adapted to several blade references. Summary of the invention

[0008] The invention satisfies this need by proposing a clamping system making it possible to immobilize the blade root in the direction of the jaws using stops which can be put in place quickly.

[0009] For this purpose, the invention proposes a system for clamping a turbomachine blade root, for example for marking it, said root having a generally elongated shape, this system comprising: - a vice comprising two jaws provided with jaws defining between them an elongated space configured to receive said foot, at least one of the jaws being movable to adjust a distance between the jaws, - a first fixed element comprising a first stop surface which is substantially perpendicular to an axis of elongation of said space and which is located at a first longitudinal end of said space, and - a second movable element, located at a second opposite longitudinal end of said space, this second element being movable between a first position in which it leaves said second end open and a second position in which it closes said second end, this second element comprising a second stop surface which is arranged opposite said first stop surface when the second element is in the second position.

[0010] The clamping system therefore makes it possible to quickly immobilize the blade root in the direction of any possible sliding between the jaws of the vice. The position of the root is thus defined unequivocally, which makes it possible to guarantee the reproducibility of the marking of the blade root.

[0011] According to other characteristics of the clamping system: - the second element is movable in a plane transverse to the axis of elongation, which passes through the second end of said space, - the second element is a latch which is carried by a first of the two jaws and, in the first position, said latch is arranged only opposite this first of the two jaws, - the latch is pivotable and has a first end which is articulated around a pivot carried by the first of the two jaws, - the latch has a second end which is shaped like a hook and which is capable of cooperating with a pin carried by a second of the two jaws to immobilize the latch in its second position, - the pivot and the pin have axes parallel to the elongation axis, - the clamping system comprises a support for resting the latch in its first position which is arranged substantially opposite the pin relative to the pivot and which projects parallel to the elongation axis from the first jaw, - the second stop surface is formed at the end of a screw which passes through an intermediate part of the latch parallel to the elongation axis, - one of the two jaws is fixed and the other of the two jaws is movable and connected to an actuator.

[0012] The invention also relates to an assembly which comprises: - a turbomachine blade comprising a blade with a general radial direction and, at a proximal end, a root having a general elongated shape in a direction perpendicular to the general radial direction of the blade, and - a system of the type described above, the foot of the blade being received in the space so that the axis of elongation of the space corresponds to the direction of the foot.

[0013] According to another characteristic of the assembly, the jaws are at least partly complementary to the shapes of the sides of the blade root.

[0014] The invention finally relates to a method for marking a blade root using an assembly of the type described above, characterized in that it comprises: - a first step during which the foot of the blade is inserted between the jaws of the vice until it comes to rest on the first stop surface, - a second stage during which the jaws are brought together until the blade root is clamped between the jaws, - a third step during which the second element and the second stop surface are moved so that the second stop surface comes to bear on the foot, and - a fourth stage during which the foot of the blade is marked between the jaws.

[0015] According to another characteristic of the method, the latter comprises a step prior to the first step during which the blade is placed in position so that its blade is at the bottom and its root at the top, presenting a free face upwards, and during the fourth step, said free face is marked. Brief description of the figures

[0016] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which: - [Fig.l] [Fig.l] is an overall perspective view of a clamping assembly according to the invention with the second movable element in its second position; - [Fig.2] [Fig.2] is a top view of a clamping assembly according to the invention with the second movable element in its second position; - [Fig.3] [Fig.3] is a top view of a clamping system according to the invention with the second movable element in its second position; - [Fig.4] [Fig.4] is an end view of a clamping assembly according to the invention with the second movable element in its first position; - [Fig.5] [Fig.5] is an end view of a clamping assembly according to the invention with the second movable element in its second position; - [Fig.6] [Fig.6] is a block diagram illustrating the steps of a process marking a blade according to the invention. Detailed description of the invention

[0017] [Fig.l] shows a clamping assembly 10 for a turbomachine blade, also called an “assembly”. The clamping assembly 10 comprises, on the one hand, a blade 12 to be clamped, comprising a blade 14 with a generally radial direction, and at a proximal end 16 of the blade 14, a platform 18 and a root 20 having a generally elongated shape in a direction X perpendicular to the general radial direction R of the blade 14. More particularly, the root 20 is intended to be mounted in a rotor disk (not shown). It forms, in a known manner, a root having a substantially constant section which is intended to be received in a notch formed in the disk, which has the same direction as the root and which is of a section substantially complementary to flanks 22 of the root 20.

[0018] The assembly 10 also and mainly comprises a system 11 for clamping the blade 12. This system 11 makes it possible, for example, in a non-limiting manner of the invention, to clamp the root 20 for the purpose of marking it. The system 11 comprises a vice 24 comprising two jaws 26, 28 provided with grips 30, 32, visible more particularly in FIGS. 3 and 4 which define between them a space 34 of elongated shape configured to receive the root 20. The space 34 extends along an axis of elongation A. When the root 20 is received in the space 34, its direction X corresponds with the axis of elongation A.

[0019] At least one of the jaws 26, 28 is movable to adjust a distance between the jaws 30, 32. This conventionally allows the introduction of the foot 20 and its clamping between the jaws 30, 32.

[0020] Advantageously, as illustrated in Figures 4 and 5, the jaws 30, 32 are at least partly complementary to flank shapes 21, 23 of the blade root 20. For this purpose, they comprise grooves 25, 27 intended to receive shapes 29, 31 complementary to the flanks 21, 23 of the root 20.

[0021] According to the invention, the clamping system 11 further comprises a first fixed element 36 comprising a first stop surface 38 which is substantially perpendicular to the axis of elongation A of the space 34 and which is located at a first longitudinal end 40 of this space 34, that is to say at a first end of the jaws 30, 32. The fixed element 32 is for example produced in the form of a bracket comprising the first surface 38.

[0022] The clamping system 24 further comprises a second movable element 42, located at a second longitudinal end 44 of the space 34, which is movable between a first position, shown in [Fig. 4], in which it leaves said second end 44 open and a second position, shown in [Fig. 5] in which it closes the second end 44. As illustrated in [Fig. 2], this second element 42 comprises a second stop surface 46 which is arranged opposite said first stop surface 38 when the second element 42 is in the second position.

[0023] The second element 42 can be movable in multiple ways as long as it allows the second end 44 to be selectively released or closed. However, in the preferred embodiment of the invention, the second element 42 is movable in a plane P transverse to the axis of elongation A, which passes through the second end 44 of the space 34.

[0024] The second element 42 could take any form capable of allowing it to be movable in the plane P, such as a sliding plate, or even a door, etc. In the preferred embodiment of the invention which has been shown in the figures, the second element 42 is a latch which is carried by a first jaw 28 of the two jaws 26, 28. In the first position which has been shown in [Fig.4], this latch 42 is arranged only opposite this first jaw 28.

[0025] There are mainly two types of latches, sliding latches and pivoting latches. In the example shown here, the latch 42 is pivoting and it has a first end 48 which is articulated around a pivot 50 carried by the first jaw 28. The pivot 50 is for example crossed by a screw 52 which is received in the first jaw 28. The pivot 50 is arranged around an axis B parallel to the elongation axis A.

[0026] The latch 42 has a second end 54 which is shaped into a hook 56. As illustrated in FIGS. 4 and 5, this hook 56 is capable of cooperating with a pin 58 carried by a second jaw 26 to immobilize the latch 42 in its second position. The pin 58, with axis C parallel to the axis A of elongation, is for example crossed by a screw 60, which is screwed into the second jaw 26.

[0027] When the latch 42 is not in use, it is important that it cannot interfere with the blade 12. For this purpose, the clamping system 11 comprises a rest support 62 for the latch 42 providing it with support in its first position. This support 52 is arranged substantially opposite the pin 58 relative to the pivot 50 and projects parallel to the axis of elongation A from the first jaw 28. The rest support 62 could be a protrusion formed in the material of the first jaw 28, however, preferably, it is formed of a stud 62 which is crossed by a screw 64 screwed into the first jaw 28.

[0028] The second stop surface 46 is intended, as has been seen, to allow the foot 20 of the blade to be clamped when the second element 42 occupies its second position. Consequently, the stop surface 46 must be able to be moved in order to be able to come into contact with the foot 20 and not leave any play along the axis A between the foot 20 and this surface 46.

[0029] The surface 46 could for example be an inclined surface carried by a face 66 of the latch 42, which would gradually come into contact with the foot 20 and would stress it as the latch is brought into its second position. However, as illustrated in FIGS. 2, 4, and 5, the surface 46 is preferably formed at the end of a screw 68 which passes through a bore 72 formed in an intermediate portion 70 of the latch 42 parallel to the axis of elongation A.

[0030] The screw 68 therefore allows precise adjustment of the position of the second stop surface 46 after the latch 42 has been folded into its second position.

[0031] As seen previously, at least one of the two jaws 26, 28 of the vice 24 is movable. In the preferred embodiment of the invention, one of the two jaws 26, 26 is fixed and the other of the two jaws is movable and connected to an actuator (not shown). Preferably here, for mass considerations, it is the first jaw 28, carrying the latch 42, which is fixed, the second jaw 26 being movable.

[0032] In this configuration, as illustrated in [Fig.6], a blade root 20 can be marked very simply using a clamping system 11 of the type described previously, in the following manner:

[0033] As shown in [Fig.6], during a preliminary step ET0, the blade 20 is placed in position so that its blade 14 is at the bottom and its root 20 at the top, presenting a free face 74 upwards.

[0034] Then, during a first step ET1, the foot 20 of the blade 12 is inserted between the jaws 26, 28 and the grips 30, 32 of the vice 24 until it comes to bear on the first stop surface 38.

[0035] Then during a second step ET2, the jaws 26, 28 are brought together until the blade root 20 is clamped between the jaws 30, 32. A third step then occurs during which the second element 42 and the second stop surface 46 are moved so that the second stop surface 46 comes to bear on the root 20. In the example shown here, this second step consists of pivoting the latch 42 so that it leaves the stud 62 and folding the latch 42 so that its hook 56 is received on the pin 58. Then, once this is done, the screw 68 is screwed so that the second contact surface 46 comes into contact with the root 20.

[0036] Finally, during a fourth step, the surface 74 of the blade root 20 is marked between the jaws 30. 32.

[0037] It will be understood that for reasons of convenience of marking and accessibility to the surface 74, the preliminary step ET0 makes it possible to simplify the marking. However, it will also be understood that this step is optional and that the marking could be carried out with the blade 14 blade at the top and the foot 20 at the bottom by presenting its free face 74 downwards, without changing the nature of the invention.

[0038] The invention therefore makes it possible to greatly simplify the marking of a turbomachine blade.

Claims

Claims

1. System (11) for clamping a root (20) of a turbine engine blade (12), said root (20) having a generally elongated shape, this system (11) comprising: - a vice (24) comprising two jaws (26, 28) provided with grips (30, 32) defining between them a space (34) of elongated shape configured to receive said root (20), at least one of the jaws (26) being movable to adjust a distance between the grips (30, 32), - a first fixed element (36) comprising a first stop surface (38) which is substantially perpendicular to an axis of elongation (A) of said space (34) and which is located at a first longitudinal end (40) of said space (34), and - a second movable element (42), located at a second longitudinal end (44) opposite said space (34), this second element (42) being movable between a first position in which it leaves said second end (44) open and a second position in which it closes said second end (44),this second element (42) comprising a second stop surface (46) which is arranged opposite said first stop surface (38) when the second element (46) is in the second position.,

2. Clamping system (11) according to the preceding claim, characterized in that the second element (42) is movable in a plane (P) transverse to the axis (A) of elongation, which passes through the second end (44) of said space (34).

3. Clamping system (11) according to the preceding claim, characterized in that the second element (42) is a latch which is carried by a first (28) of the two jaws (26, 28) and in that, in the first position, said latch is arranged only opposite this first (28) of the two jaws (26, 28),

4. Clamping system (11) according to the preceding claim, characterized in that the latch (42) is pivotable and has a first end (48) which is articulated around a pivot (50) carried by the first (28) of the two jaws.

5. Clamping system (11) according to the preceding claim, characterized in that the latch (42) comprises a second end (54) which is shaped like a hook (56) and which is capable of cooperating with a pin (58) carried by a second (26) of the two jaws (26, 28) to immobilize the latch (42) in its second position.

6. Clamping system (11) according to claims 4 and 5 taken in combination, characterized in that the pivot (50) and the pin (58) have axes (B, C) parallel to the axis (A) of elongation.

7. Clamping system (11) according to one of claims 4 to 6, characterized in that it comprises a rest support (62) for the latch (42) in its first position which is arranged substantially opposite the pin (58) relative to the pivot (50), and which projects parallel to the elongation axis (A) from the first jaw (28).

8. Clamping system (11) according to one of claims 3 to 7, characterized in that the second stop surface (46) is formed at the end of a screw (64) which passes through an intermediate part of the latch parallel to the elongation axis.

9. Clamping system (11) according to one of the preceding claims, characterized in that one (28) of the two jaws (26, 28) is fixed, and in that the other (26) of the two jaws (26, 28) is movable and connected to an actuator.

10. Assembly (10), characterized in that it comprises: - a turbomachine blade (12) comprising a blade (14) of general radial direction (R) and, at a proximal end (16), a root (20) having a general elongated shape in a direction perpendicular (X) to the general radial direction (R) of the blade (14), and - a system (11) according to one of claims 1 to 9, the root (20) of the blade (12) being received in the space (34) so that the axis (A) of elongation of the space corresponds to the direction (X) of the root (20).

11. Assembly (10) according to the preceding claim, characterized in that the jaws (30, 32) are at least partly complementary to flank shapes (21, 23) of the blade root (20), the jaws (30, 32) comprising grooves (25, 27) intended to receive complementary shapes of the flanks (21, 23) of the blade root (20).

12. Method for marking a blade root (20) using an assembly (10) according to claim 10 or 11, characterized in that it comprises:

13. - a first step (ET1) during which the foot (20) of the blade (12) is inserted between the jaws (26, 28) of the vice (24) until it comes to bear on the first stop surface (46), - a second step (ET2) during which the jaws (26, 28) are brought together until the blade root (20) is clamped between the jaws (30, 32), - a third step (ET3) during which the second element (42) and the second stop surface (46) are moved so that the second stop surface (46) comes to bear on the foot (20), and - a fourth step (ET4) during which the foot (20) of the blade is marked between the jaws (30, 32). Marking method according to the preceding claim, characterized in that it comprises a step (ET0) preliminary to the first step (ET1) during which the blade (10) is placed in position so that its blade (14) is at the bottom and its root (20) at the top, presenting a free face (74) upwards, and in that during the fourth step (74), said free face (74) is marked.

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