FR3111167A1 - FIXING COLLAR TIGHTENING DEVICE - Google Patents

Abstract

COLLAR CLAMP DEVICE One aspect of the invention relates to a clamp device (12), comprising: an open loop (20) having an inside diameter; two extensions (21, 22) integral with the open loop (20), each comprising an opening and a distance (E) of which is called the air gap, the air gap (E) being maximum when the tightening device (12) is open and minimal when the clamping device (12) is closed; and an assembly part (40) passing through each opening of the extensions (21, 22) and exerting a closing force on the two extensions (21, 22); the tightening device (12) also comprises an elastically deformable element (30) having a stiffness, arranged between the two extensions (21, 22) and exerting a restoring force on the two extensions (21, 22) proportionally opposite to the reduction of the air gap (E). Figure to be published with abstract: Figure 3

Description

FIXING COLLAR CLAMP DEVICE

TECHNICAL FIELD OF THE INVENTION

The technical field of the invention relates to the cooling system of an aircraft engine, more particularly the attachment of cooling tubes.

TECHNOLOGICAL BACKGROUND OF THE INVENTION

Twin-spool turbojets have a so-called “low-pressure turbine” part comprising cooling tubes surrounding the casing of the low-pressure turbine and allowing the turbine casing to be cooled when the engine is in operation. Each cooling tube runs along the surface of the casing in order to cool it, thus making it possible to control the play between the moving wheels and the turbine casing and thus optimize the efficiency of the engine.

The cooling tubes are assembled and held in place by ramp supports using clamps in which the tubes must be able to slide. However, the cooling tubes may show damage due to the friction of the tubes in their collars. An analysis of the causes shows that certain collars are too tight causing vibrations or translations of the tubes. This leads to wear of the tube in contact with the sheath of the clamps or in the event of tearing of the said sheath, metal-metal contact leading to premature wear.

• le jeu pouvant être négatif en position ouverte (tube légèrement plus gros), la fermeture du collier va exercer un serrage trop important ; et
• les dispersions géométriques des colliers et des tubes ont une répercussion directe sur le serrage qui peut ainsi varier d’un montage à l’autre.

In the open position, the clearance between the tube and the collar varies by a few tenths of a millimetre. Two observations stand out:

• as the clearance may be negative in the open position (slightly larger tube), closing the collar will exert excessive tightening; And
• the geometric dispersions of the collars and the tubes have a direct impact on the tightening which can thus vary from one assembly to another.

The invention offers a solution to the problems mentioned above, by making it possible to control the level of tightening of the collars so as to provide optimum tightening and compensate for the geometric dispersion of the tubes by avoiding excessive tightening of the collars around the tubes.

• une boucle ouverte ayant un diamètre intérieur, le diamètre intérieur étant maximal lorsque le dispositif de serrage est ouvert et minimal lorsque le dispositif de serrage est fermé ;
• deux prolongements solidaires de la boucle ouverte, chaque prolongement comportant une ouverture et dont une distance entre lesdits prolongements mesurée au niveau des ouvertures est appelée entrefer, l'entrefer étant maximal lorsque le dispositif de serrage est ouvert et minimal lorsque le dispositif de serrage est fermé ; et
• une pièce d'assemblage passant dans chaque ouverture des prolongements et exerçant une force de fermeture sur les deux prolongements ;

The invention relates to a clamping device which can pass from an open state to a closed state, comprising:

• an open loop having an inside diameter, the inside diameter being maximum when the clamp is open and minimum when the clamp is closed;
• two extensions integral with the open loop, each extension comprising an opening and of which a distance between the said extensions measured at the level of the openings is called air gap, the air gap being maximum when the tightening device is open and minimum when the tightening device is closed ; And
• an assembly part passing through each opening of the extensions and exerting a closing force on the two extensions;

The clamping device is remarkable in that it also comprises an elastically deformable element having a stiffness, arranged between the two extensions and exerting a restoring force on the two extensions proportionally opposite to the reduction in the air gap.

By "reduction of the air gap" or "reduction of the air gap", we mean the reduction of the distance between the two extensions.

We will call "tightening" the operation consisting in passing the clamping device from the open state to the closed state. Conversely, we will call "opening" the operation consisting in changing the clamping device from the closed state to the open state.

When tightening the device by means of the assembly part, the user compensates for the restoring force exerted by the elastically deformable element, proportional to the reduction in the air gap. The spring force provides measurable feedback to the user of the decrease in air gap.

In addition to the characteristics which have just been mentioned in the previous paragraph, the clamping device may have one or more additional characteristics among the following, considered individually or in all technically possible combinations.

According to a first embodiment of the clamping device, the elastically deformable element is a spring. The spring has two ends, each end being coupled to one of the extensions of the clamp. In this way, the spring is compressed when the air gap is reduced.

According to a second embodiment of the clamping device, the elastically deformable element comprises at least one spring washer, called Belleville washer, having a flattening stiffness. The Belleville washer features a truncated cone shape with a small base (otherwise known as apex) and a large base. The Belleville puck includes an orientation perpendicular to the large base and the small base and directed from the large base to the small base. When the Belleville washer is flattened, the small base moves closer to the large base. When the Belleville washer is flattened, a restoring force appears, opposite to the flattening, proportional to the stiffness at the flattening. The Belleville washer is arranged between the two extensions so that the reduction in the air gap flattens the Belleville washer. In this way, the Belleville washer exerts the restoring force, opposed to the reduction of the air gap, proportional to the stiffness on flattening.

According to a first variant of the second embodiment, which can be combined with a second variant described below, the elastically deformable element comprises at least two Belleville washers stacked in series, also called stacking in opposition. The orientation of each Belleville washer is alternated. The Belleville washers are superimposed and connected two by two, head to tail, by their respective small bases or their respective large bases. The total stiffness of a series stack of Belleville washers having the same flattening stiffness is equal to the flattening stiffness divided by the number of Belleville washers within the stack.

According to the second variant of the second embodiment, which can be combined with the first variant described above, the elastically deformable element comprises at least two Belleville washers stacked in parallel, also called stacking in a packet. In a parallel stack, the orientation of each overlapping Belleville washer is the same. The total stiffness of a parallel stack is equal to the sum of the flattening stiffness of each Belleville washer.

The stack of Belleville washers in series and/or in parallel makes it possible to adjust the total stiffness of the elastically deformable element. It also makes it possible to adjust the height of the elastically deformable element.

The elastically deformable element may comprise an opening through which the assembly part passes. In this way, the assembly part retains and centers the spring or the Belleville washers during the flattening of the deformable element, avoiding for example the collapse of the stack of Belleville washers and the uncontrolled variation of the total stiffness of said stacking. The assembly part also makes it possible to guarantee the orientation and the arrangement of each washer during the manufacture or use of the device.

The assembly part can for example comprise a screw and a nut. The screw passes through each opening of the extensions. The head of the screw and the nut are arranged on either side of the two extensions. Thus the tightening of the nut on the screw makes it possible to apply a force to each extension aimed at closing the tightening device. The closing force applied to the extensions is proportional to the tightening torque of the nut on the screw. A torque wrench makes it possible, for example, to apply a determined tightening torque to the screw/nut assembly.

• un tube ;
• un ancrage ;
• un dispositif de serrage présentant l'une quelconque des caractéristiques précédentes ;

The invention also relates to a holding system comprising:

• a tube ;
• an anchor;
• a clamping device having any of the preceding characteristics;

The holding system is remarkable in that the device tightens the circumference of the tube and is fixed to the anchorage via the assembly part.

Preferably, the nominal diameter of the tube is less than or equal to the maximum diameter of the open loop and greater than or equal to the minimum diameter of the open loop.

• un tube de refroidissement ;
• un support de rampe ;
• un dispositif de serrage présentant l'une quelconque des caractéristiques précédentes ;

The invention further relates to a low pressure turbine casing comprising:

• a cooling tube;
• a ramp support;
• a clamping device having any of the preceding features;

The low pressure turbine housing is remarkable in that the cooling tube is held by the clamping device on the rail support.

• une étape de détermination d'une force de fermeture seuil à partir de la raideur de l'élément déformable élastiquement, de l'entrefer, du diamètre maximal de la boucle ouverte et du diamètre nominal du tube ;
• une étape de serrage du dispositif de serrage autour de la circonférence du tube au cours de laquelle la force de fermeture appliquée par la pièce d'assemblage est mesurée en continue par le moyen de mesure, l'étape de serrage étant interrompue lorsque la force de fermeture mesurée atteint la force de fermeture seuil.

The invention also relates to a method of clamping a tube by means of a clamping device having any one of the preceding characteristics and a means for measuring the closing force applied by the assembly part, the nominal diameter of the tube being less than or equal to the maximum diameter of the open loop of the clamping device and greater than or equal to the minimum diameter of the open loop of the clamping device, the clamping method comprising the following steps:

• a step of determining a threshold closing force from the stiffness of the elastically deformable element, the air gap, the maximum diameter of the open loop and the nominal diameter of the tube;
• a clamping step of the clamping device around the circumference of the tube during which the closing force applied by the assembly part is continuously measured by the measuring means, the clamping step being interrupted when the clamping force measured closing reaches the closing force threshold.

The optimal tightening of the device around the tube must maintain the tube in position but also allow the tube to slide in the device. The optimum diameter of the open loop is therefore greater than or equal to the nominal diameter of the tube.

An optimal diameter of the open loop corresponds to an optimal reduction of the air gap. This optimum reduction of the air gap, which is equal to an optimum deformation of the elastically deformable element, corresponds to a restoring force which we will call threshold restoring force. To ensure optimal tightening of the device, it is then sufficient to apply the threshold closing force, thanks to the assembly part, equal and opposite to the threshold restoring force. The joint is actuated by measuring the applied closing force which increases as the device squeezes the tube. When the closing force reaches the closing force threshold, the tightening is optimal.

The diameter of the tube can present a dispersion around the nominal diameter. The nominal diameter of the tube is, for example, between 10 mm and 50 mm. The resulting mechanical play between the diameter of the tube and the maximum diameter of the open loop is for example between -0.4 mm and +0.4 mm, ie a relative play of between -4% and 4%.

During the tightening phase, when the mechanical clearance is negative, i.e. when the diameter of the tube is greater than the nominal diameter, the open loop comes into contact with the circumference of the tube before the air gap reaches the reduction optimal. The closing force then opposes the restoring force of the elastically deformable element added to the compression force of the loop on the circumference of the tube. The stiffness of the tube being higher than the stiffness of the deformable element, the apparent restoring force of the clamping device in contact with the tube is also higher than the restoring force of the deformable element alone. Therefore, the measured closing force reaches the threshold closing force and the tightening step is interrupted before the air gap reaches the optimum reduction of the air gap. The clamping force on the tube is thus limited, offering the tube the possibility of sliding in the clamping device.

When the mechanical play is positive, i.e. when the diameter of the tube is less than the nominal diameter, the open loop does not come into contact with the tube before having reached the optimum diameter, the threshold closing force being reached when the air gap reaches the optimal reduction. Thus the tube can slide in the device.

The invention and its various applications will be better understood on reading the following description and examining the accompanying figures.

BRIEF DESCRIPTION OF FIGURES

The figures are presented for information only and in no way limit the invention.

schematically shows a first embodiment of a clamping device in an open state.

schematically shows the first embodiment of the clamping device in a closed state.

schematically presents the first embodiment of the clamping device, implemented within an example of a holding system.

schematically presents a second embodiment of the clamping device, centered on the extensions.

schematically shows, in section view and in top view, a Belleville washer.

schematically presents a first and a second variant of the second embodiment of the clamping device as well as a combination of the first and second variants of this same embodiment.

schematically shows one embodiment of a low pressure turbine casing.

schematically shows an enlargement of the embodiment of the low pressure turbine casing.

schematically presents a mode of implementation of a tightening method of the clamping device.

DETAILED DESCRIPTION

The figures are presented for information only and in no way limit the invention. Unless specified otherwise, the same element appearing in different figures has a single reference.

Figures 1 and 2 schematically show a first embodiment of a clamping device 11 in two states: an open state and a closed state. The open state is shown in Figure 1 and the closed state is shown in Figure 2. The clamping device 11 comprises an open loop 20, first and second extensions 21, 22, a deformable element 30 and a piece of assembly 40.

The open loop 20 is formed from a strip, part of the strip being rolled up on itself so as to form a "C" which would rest on a cylinder of diameter A. The part of the strip forming the "C" comprises two ends from which the two extensions 21, 22 stretch radially. The two extensions 21, 22 and the open loop 20 advantageously constitute one and the same part and are preferably made of metal. Each extension 21, 22 has an opening. The space between the extensions 21, 22 measured at the level of the openings is called air gap E.

The clamping device 11 can switch continuously from the open state to the closed state. In the open state, the tightening device 11 is at rest, the open loop 20 has a maximum diameter A ₁ and the air gap is maximum E ₁ . In the closed state, the open loop 20 has a minimum diameter A ₀ and the air gap is minimum E ₀ .

The assembly part 40 passes through the opening of each extension 21, 22. The assembly part 40 thus makes it possible to exert a closing force on each extension 21, 22. In the example of FIGS. 1 and 2, assembly part 40 is a screw with a nut. The screw passes through the opening of each extension 21, 22, the head of the screw being supported on the second extension 22. The nut is supported on the first extension 21. Thus by actuating the assembly part 40 , that is to say by tightening the nut on the screw, the closing force brings the extensions 21, 22 closer and closes the clamping device 11. The assembly part can advantageously be a single screw or any other mechanism putting in creates a helical connection. In an example where the assembly part 40 is a single screw, the opening of the first extension 21 comprises a thread in which the screw is inserted and the head of the screw bears against the second extension. In this way, by tightening the screw, the closing force brings the two extensions 21, 22 closer and closes the clamping device 11. The advantage of using the screw alone or with the nut or any other mechanism implementing a helical connection is that the tightening torque exerted on the assembly part 40 is proportional to the closing force applied to the extensions 21, 22.

The elastically deformable element 30 is arranged between the extensions 21, 22. In this way the elastically deformable element 30 is compressed when the air gap E is reduced. The length of the elastically deformable element 30 at rest is advantageously equal to the maximum air gap E ₁ . Thus when the clamping device 11 is open, the elastically deformable element 30 is advantageously at rest, resting on each extension 21, 22. The deformation of the deformable element 30, denoted , is thus equal to the reduction of the air gap E.

The law of behavior of the deformable element 30 is preferably known, either by characterization using a test bench, or by modeling. However, the behavior law of the deformable element 30 is approximated by a linear behavior law such as Hooke's law. According to Hooke's law, the elastically deformable element 30 is characterized by its stiffness, denoted . Thus when the deformable element 30 undergoes a deformation, it exerts a restoring force, denoted . The restoring force being related to the deformation by : .

When the clamping device 11 closes, that is to say when the extensions 21, 22 come together, the deformable element 30 exerts the restoring force on each of the extensions 21, 22, opposed to the reduction of the air gap E. By knowing the closing force, which is applied to the extensions 21, 22, to compress the deformable element 30, the deformation is thus provided of the deformable element 30, and therefore the reduction of the air gap E.

In the example of Figures 1 and 2, the elastically deformable element 30 is a spring, each end of the spring 30 being coupled respectively with each extension 21, 22. The deformation of the spring 30 corresponds to a compression, in other words a shortening of the length of the spring 30.

• un tube 1 ;
• un ancrage 2 ; et
• un dispositif de serrage 12 selon le premier mode de réalisation.

Figure 3 schematically shows an example of a holding system 60. The holding system 60 comprises:

• a pipe 1;
• an anchor 2; And
• a clamping device 12 according to the first embodiment.

The clamping device 12, in this first embodiment, further comprises a gasket 23. The gasket 23 is arranged on the internal part of the open loop 20. When the tube 1 is introduced into the open loop 20, it comes into support on the gasket 23. When the device 12 is tightened, the open loop 20 encloses the circumference of the tube 1 via the gasket 23. The gasket 23 makes it possible to avoid metal/metal contact when the clamping device 12 tightens the tube 1, thus preventing premature wear of the device 12 and of the tube 1. The lining 23 is preferentially elastic in order to attenuate the vibrations or the expansions of the tube 1. If the tube 1 is not correctly aligned in the loop , the elasticity of the lining 23 also makes it possible to carry out the tightening without decentering the tube 1.

In this example of the first embodiment of the device, the extensions 21, 22 extend parallel, from each end of the open loop 20 outwards. However, the extensions 21, 22 extend in a direction different from the radial direction with respect to the loop 20. The extensions 21, 22 stretch obliquely in order to be more easily pressed against the anchor 2 and thus ensure correctly maintaining the tube 1.

In the example of Figure 3, the assembly part 40 is formed by a screw and a nut. The screw of the assembly part 40 passes through the extensions 21, 22 and an opening of the anchor 2. In this way the assembly part 40 comes to exert the closing force on the second extension 22 and the first extension 21 by through the anchor 2. In addition, the assembly part 40 makes it possible to press the clamping device 12 against the anchor. Thus the tube 1 is held in a fixed position relative to the anchor 2.

FIG. 4 schematically presents a second embodiment of the clamping device 13 and more particularly a first variant of this second embodiment. According to this first variant, the deformable element 31 is a stack formed by a plurality of spring washers 50 called "Belleville washers". Belleville 50 washer stack is characterized by its height and stiffness , adjustable according to the number of washers 50 and the type of stack used, discussed below in the description. Each Belleville washer 50 has an opening in its center through which the assembly part 40 passes. The assembly part 40 thus retains the Belleville washers 50 when the device 13 is tightened, thus avoiding the collapse of the deformable element 31 as well as the uncontrolled variation of its stiffness .

Figure 5 schematically shows, in side sectional view and in top view, a Belleville washer 50. The Belleville washer 50 has the shape of a hollow, truncated cone, comprising a small base with a diameter D1 and a large base with a diameter D2 . The Belleville 50 washer is characterized by its flattening stiffness , his height and the thickness of its side wall. The Belleville 50 washer behaves mechanically like a spring when subjected to flattening, ie the small base is brought closer to the large base. The maximum flattening of the Belleville 50 puck depends on its height at rest and its thickness . The maximum deformation that the Belleville washer can undergo is equal to . We define the orientation N of a Belleville washer as being perpendicular to the large base and to the small base and directed from the large base towards the small base.

Belleville washers 50 can be stacked in different ways so as to obtain a deformable element 31, 32, 33 having a different height and stiffness. FIG. 6 schematically presents two variants of the second embodiment of device 13 as well as a combination of these two variant embodiments of device 13.

The first variant embodiment is implemented in particular in the example of FIG. 4. According to the first variant embodiment, the deformable element 31 is produced by a so-called stacking in series or in opposition. In this type of stack, the orientation of each Belleville washer 50 is alternated. The Belleville 50 washers are connected two by two head to tail, ie connected by their respective small bases or their respective large bases. Stiffness of the deformable element 31 formed by 6 Belleville washers each having the same stiffness is equal : .

According to a second variant embodiment, the deformable element 32 is produced by a so-called parallel stack or stack. In this type of stack, the Belleville washers 50 are superimposed on each other while keeping the orientations of each Belleville washer 50 parallel to each other. The total stiffness of the deformable element 32 formed by 6 Belleville washers each having the same stiffness is equal : .

According to the combination of the first variant with the second variant embodiment, the deformable element 33 is produced by combining the series and parallel stacks. Belleville 50 washers are stacked in parallel in groups of three. These stacks of three Belleville 50 washers are then stacked in series. The advantage of proceeding in this way is to adjust the stiffness of the deformable element 33. The total stiffness of the deformable element 33 formed by 6 Belleville washers each having the same stiffness Equals .

An embodiment of a low pressure turbine housing 71 will be presented with reference to Figures 7 and 8.

FIG. 7 presents a partial view of a low-pressure turbine 70. The turbine casing 71 has the shape of a nozzle, the combustion gases flowing along the axis M. The turbine casing 71 is surrounded by a plurality of cooling tubes 72, forming a cooling ramp 73, responsible for cooling the casing 71. The cooling ramp 73 is held to a ramp support 74, integral with the turbine casing 71, by means of a plurality of clamping devices 13. Each clamping device 13 is attached to one of the tabs 75 of the ramp support 74.

Figure 8 shows an enlargement of Figure 7, centered on one of the clamping devices 13. One of the cooling tubes 72 of the ramp 73 passes through the loop 20 of the clamping device 13. The clamping device 13 here also presents the gasket 23 against which the cooling tube 72 comes to rest. The extensions 21, 22 extend perpendicularly to the ramp support 74. The second extension 22 bears against one of the tabs 75. The extensions 21, 22 and the element deformable 31 are fixed and tightened against the tab 75 by means of the assembly part 40, in this case, a screw with a nut.

• une étape de détermination 101 de la force de fermeture seuil à exercer sur la pièce de fermeture 40 afin de réaliser un serrage optimal du tube 1 ; et
• une étape de serrage 102 du dispositif de serrage 11, 12, 13 autour de la circonférence du tube 1.

FIG. 9 schematically presents a mode of implementation of a method of tightening 100 of the clamping device 11, 12, 13 around the tube 1, implementing a means of measuring the closing force applied by the workpiece. assembly 40. The method comprises two steps 101, 102, executed consecutively in the order presented as follows:

• a step 101 for determining the threshold closing force to be exerted on the closing piece 40 in order to achieve optimum tightening of the tube 1; And
• a clamping step 102 of the clamping device 11, 12, 13 around the circumference of the tube 1.

• du diamètre du tube 1 ; et
• de la loi de comportement mécanique de l'élément déformable 30, 31, 32, 33, exprimant la force de rappel , exercée par l'élément déformable 30, 31, 32, 33 en fonction de sa déformation .

During the determination step 101, the threshold closing force is calculated taking into account:

• the diameter of the tube 1; And
• of the mechanical behavior law of the deformable element 30, 31, 32, 33, expressing the restoring force , exerted by the deformable element 30, 31, 32, 33 as a function of its deformation .

To an optimal tightening corresponds an optimal diameter A ^OPT of the open loop 20 and therefore an optimal value of the air gap E ^OPT , which should be determined according to the nominal diameter of the tube 1, the presence and the thickness of the gasket 23 or any other parameter that may have an influence on the optimum value of the air gap E ^OPT . To the optimal value of the air gap E ^OPT corresponds an optimal deformation of the deformable element 30. Thus the optimum restoring force of the deformable element 30 undergoing the optimum deformation is obtained thanks to its mechanical behavior law. If for example the law of mechanical behavior is a law of Hooke, the optimal restoring force is obtained by . Thus the threshold closing force to be exerted on each extension 21, 22 is equal and opposite to the optimum restoring force .

During the tightening step 102, the closing force applied by the assembly part 40 is measured continuously by the measuring means. For example, if the assembly part is a screw/nut assembly, the measuring means can be a torque wrench making it possible to measure the torque exerted or set to trigger when the torque exerted on the nut corresponds to the threshold closing force. When the closing force threshold is reached step 102 of tightening is interrupted. The tightening achieved is thus optimal.

Claims (10)

Clamping device (11, 12, 13) which can pass from an open state to a closed state, comprising:

• an open loop (20) having an inside diameter (A), the inside diameter being maximum (A ₁ ) when the tightening device (11, 12, 13) is open and minimum (A ₀ ) when the tightening device (11 , 12, 13) is closed;
• two extensions (21, 22) integral with the open loop (20), each extension (21, 22) comprising an opening and of which a distance (E) between said extensions (21, 22) measured at the level of the openings is called air gap, the air gap (E) being maximum (E ₁ ) when the clamping device (11, 12, 13) is open and minimum (E ₀ ) when the clamping device (11, 12, 13) is closed; And
• an assembly part (40) passing through each opening of the extensions (21, 22) and exerting a closing force on the two extensions (21, 22);

the clamping device (11, 12, 13) being characterized in that it also comprises an elastically deformable element (30, 31, 32, 33) having a stiffness, arranged between the two extensions (21, 22) and exerting a restoring force on the two extensions (21, 22) proportionally opposite to the reduction in the air gap (E). Device (11, 12, 13) according to claim 1, in which the elastically deformable element (30) is a spring. Device (11, 12, 13) according to claim 1, in which the elastically deformable element (31, 32, 33) comprises at least one spring washer (50), called a Belleville washer, having a flattening stiffness. Device (11, 12, 13) according to Claim 3, in which the elastically deformable element (31, 33) comprises at least two Belleville washers (50) stacked in series. Device (11, 12, 13) according to any one of claims 3 or 4, in which the elastically deformable element (32, 33) comprises at least two Belleville washers (50) stacked in parallel. Device (11, 12, 13) according to any one of the preceding claims, in which the elastically deformable element (30) comprises an opening through which the assembly part (40) passes. Device (11, 12, 13) according to any one of the preceding claims, in which the assembly part (40) comprises a screw and a nut. Holding system (60) comprising:

• a tube (1);
• an anchor (2);
• a clamping device (11, 12, 13) according to any one of claims 1 to 7;

the device (11, 12, 13) clamping the circumference of the tube (1) and being fixed to the anchor (2) via the assembly part (40). Low pressure turbine casing (71) comprising:

• a cooling tube (72);
• a ramp support (74);
• a clamping device (11, 12, 13) according to any one of claims 1 to 7;

characterized in that the cooling tube (72) is held by the clamping device (11, 12, 13) on the ramp support (74). Method of clamping (100) a tube (1) by means of a clamping device (11, 12, 13) according to any one of claims 1 to 7 and means for measuring the closing force applied by the assembly part (40), the nominal diameter of the tube (1) being less than or equal to the maximum diameter (A₁) of the open loop (20) and greater than or equal to the minimum diameter (A₀) of the open loop (20) of the clamping device (11, 12, 13), the clamping method (100) comprising the following steps:

• a step of determining (101) a threshold closing force from the stiffness of the elastically deformable element (30, 31, 32, 33), the air gap (E), the maximum diameter (A ₁ ) the open loop (20) and the nominal diameter of the tube (1);
• a clamping step (102) of the clamping device (11, 12, 13) around the circumference of the tube (1) during which the closing force applied by the assembly part (40) is continuously measured by the measuring means, the clamping step (102) being interrupted when the measured closing force reaches the threshold closing force.