FR3083311A1 - MEASURING BENCH OF OPERATING PARAMETERS OF A PIVOTING DOOR OF A TURBOMACHINE - Google Patents

Abstract

Measuring bench (70) for operating parameters of a pivoting door (40) of a turbomachine, such as a discharge door (40), comprising at least at least one opening (42) for gas passage, a panel ( 44) pivoting, and a seal (72) bordering said panel (44), characterized in that the measurement bench (70) comprises: - a casing (74) supplied with pressurized air (G) and comprising l opening (42) for gas passage, - a first axis (A1) of articulation of the door (40), - a movement transmission member (84) oriented in a direction (D1) perpendicular to the first axis (A1 ), linked to the panel (44) - a biasing element (90) oriented in a direction (R2) perpendicular to the first axis (A1) and to the transmission member (84), linked to said transmission member (84) , - at least one measuring means (110, 132) of a parameter representative of the stress exerted by said biasing element (90).

Description

BENCH OF MEASUREMENT OF OPERATING PARAMETERS OF A PIVOTING DOOR OF TURBOMACHINE

The invention relates to a bench for measuring the operating parameters of a pivoting door of a turbomachine, such as a discharge door, in particular of a compressor of said turbomachine.

STATE OF THE PRIOR ART

A turbomachine gas discharge door is conventionally carried by an inter-vein casing of said turbomachine which separates a primary flow vein of the turbomachine from a secondary flow vein of said turbomachine. The door is mounted on this casing and it includes a panel capable of closing a gas passage opening of said casing or of discovering said opening at a determined opening angle. On the housing, the panel is generally mounted on the side of the secondary flow stream.

Such a door generally comprises a panel which has an edge articulated by a hinge of articulation along a first axis relative to a plate fixed to said casing. The panel has a face facing the secondary flow stream, and from which protrudes a yoke receiving an articulation axis parallel to the first axis which is connected to a generally complex actuation mechanism, in turn driven by an actuator .

The constituent parts of this actuation mechanism are generally in high number and generally have combined movements of rotation and translation or simple movements which it is difficult to instrument to carry out in situ measurements on the turbomachine.

However, it is desirable to know a certain number of operating parameters of the door in order to be able to adequately control the actuator during engine operation in order to obtain the desired response from the turbomachine during opening. or closing the door.

In particular, it is desirable to be able to control the leakage rate passing through the door. For this it is desirable to be able to determine the leakage rate passing through the door as a function of its angular opening, and in particular, to know reciprocally the value of the minimum opening angle producing a significant leak.

Another problem concerns the closing of the door. It is desirable to know the force to be applied to the door panel, and therefore the force that the actuator must exert to cause sufficient crushing of a seal carried by the panel capable of keeping the door in a closed position. , that is to say a position in which the gas flow through the opening is zero and in which the panel is considered to close the opening in a sealed manner.

There is therefore a real need for a device making it possible to measure the influence of the opening of the door on the gas flow rate passing through the opening and the force applied to the door ensuring its closing.

STATEMENT OF THE INVENTION

The invention meets this need by proposing a simplified test bench making it possible to carry out the aforementioned measurements without instrumenting the turbomachine.

To this end, the invention provides a bench for measuring the operating parameters of a pivoting door of a turbomachine, such as a discharge door comprising at least at least one gas passage opening, a pivoting panel, and a seal. sealing bordering said panel which cooperates with said opening, characterized in that the measuring device comprises:

• a casing which has a wall which delimits an interior chamber supplied with pressurized air and in which the opening is formed, • a first axis by means of which the panel is articulated on the casing between a closed position of the opening and an opening release position, • a movement transmission member oriented in a gas flow direction perpendicular to the first axis, the transmission member being pivotally mounted on said casing around a second parallel axis to said first axis and comprising a first end articulated on said panel and a second opposite end, • a biasing element, oriented in a direction perpendicular to the first axis and to the transmission member, the biasing element comprising a first connected end said false casing and a second opposite end articulated on said second end of the transmission member n, • at least one means for measuring a parameter representative of the stress exerted by said stress element.

According to other characteristics of the measurement bench:

- The biasing element is configured to be at least deployable in its direction of orientation, it comprises a first means of measuring the deployment of the biasing element and the measurement bench comprises a second means of measuring a flow rate leakage of pressurized air leaving the interior chamber of the housing,

- the biasing element comprises at least one deployable turnbuckle comprising:

a fastening yoke adapted to be connected to the false casing, a first threaded rod secured to the fastening yoke, • the second end of the biasing element, comprising a third hinge pin at the second end of the transmission member, • a second threaded rod, threaded in the opposite direction to the first threaded rod, and integral with said second end, • a tubular sleeve comprising at its ends two threads receiving the first and second threaded rods, • locknuts blocking the first and second threaded rods against the sleeve,

- The first measuring means is placed on the turnbuckle and comprises a tubular yoke which has a thread crossed by the second threaded rod and which is immobilized on said second threaded rod by a lock nut, and a slider extending perpendicularly relative to to an axis of said tubular yoke, the displacement of said cursor along said axis defining the deployment of the turnbuckle,

- The biasing element is configured to be further retractable in its direction, it further comprises a retractable traction means and a third force measurement means, which are arranged in series between the clevis of the turnbuckle and the casing, and said measurement bench comprises an adjustable stop means of the transmission member associated with a sealed closing position of the door,

the retractable traction means comprises a screw tensioner and the third force measurement means comprises a dynamometer,

- The transmission member is shaped in the form of a lever which is pivotally mounted on the false casing via the second axis and whose first and second opposite ends comprise oblong rectilinear lights aligned with one other which receive respectively in sliding:

• the third articulation axis carried by the second end of the biasing element, • a fourth axis, parallel to the first axis which is carried by a yoke which projects from the door panel,

- The housing includes a support which projects outwards from its wall, which carries the second pivot axis of the lever, and a bracket which extends from said support above the lever on the side of the element of axial stress and which is crossed by a contact screw capable of coming into contact with the lever to form the third stop means.

The invention also relates to a method for measuring a leakage rate in operation of a turbomachine gas discharge door as a function of its angular opening by means of a measurement bench of the type described above, characterized in that 'it comprises :

• a first step during which the fixing bolt of the turnbuckle is fixed directly to the casing, • at least a second step of unlocking the turnbuckle locknuts, • at least a third step during which the socket of the turnbuckle is operated to cause a determined axial deployment of said turnbuckle and consequently a determined angular opening of the door, • at least a fourth step of locking the turnbuckle locknuts, • at least a fifth step of measuring a leakage rate associated with said opening angular determined, using the second measuring means.

Finally, the invention relates to a method for measuring a closing force of a turbomachine gas discharge door by means of a measuring bench of the type described above, characterized in that it comprises:

• a first step during which the clevis attachment bolt is fixed to the casing by means of the dynamometer and the screw tensioner mounted in series, • a second step during which the screw tensioner is operated up to in the closed position according to which compression of the door seal ensures the seal between the door and the gas passage opening, • a third step during which the lever is blocked with the stop screw, • a fourth stage during which the tensile force exerted by the screw tensioner is measured using the dynamometer.

DESCRIPTION OF THE FIGURES

The invention will be better understood and other details, characteristics and advantages of the present invention will appear more clearly on reading the description which follows, given by way of nonlimiting example and with reference to the appended drawings, in which:

- Figure 1 is a general view in axial section of the upstream part of a turbofan engine;

- Figure 2 is a perspective view of a swing door discharge system of the low pressure compressor of the turbojet;

- Figure 3 is a perspective view of detail of the articulation of the pivoting post of the discharge system of Figure 2;

- Figure 4 is a sectional view of a test bench according to the invention shown in a first configuration for measuring a leakage rate passing through a gas passage opening associated with the door, depending on the opening of said door;

- Figure 5 is a detailed view of the articulation of a door panel on a housing of the test bench of Figure 4;

- Figure 6 is a detail view of the seat of the door of Figure 4;

- Figure 7 is a sectional view of the test stand according to the invention shown in the first configuration;

- Figure 8 is a sectional view of the test stand according to the invention shown in a second configuration for measuring a door closing force;

- Figure 9 is a block diagram illustrating the steps of a method for measuring a leakage rate in operation of a gas turbine engine discharge door;

- Figure 10 is a block diagram illustrating the steps of a method for measuring a closing force of a turbomachine gas discharge door.

DETAILED DESCRIPTION

In the following description, identical reference numerals designate identical parts or having similar functions. The upstream and downstream designations are defined with respect to a direction of flow of the gases inside a turbomachine.

Referring to FIG. 1, we see the upstream part of a turbofan 10 double flow with high dilution rate, comprising a blower 12 which compresses the air entering the air intake duct of the engine, before this is not divided between the primary flow P which circulates in a primary vein 14 by first passing through a low pressure compressor BP 16 then a high pressure compressor HP 18, and the secondary flow S which circulates in a secondary vein 20 to be ejected and join at the level of a nozzle (not shown) the primary flow P. The secondary stream 20 is crossed by arms 22 of an intermediate casing 24 which connect the upstream structural part of the engine to organs for taking up forces, on the aircraft, configured to take up forces generated by the engine. The arms 22, as such, are intended to be connected to a part 26 of an outer casing 28. The arms 22 each have a shape of fin oriented in a secondary flow S in order to minimize its aerodynamic impact.

The air flowing in the primary stream 14 passes through the BP compressor 16 for a first compression then the intermediate casing 24 at the level of the arms 22 and undergoes a second compression by the high pressure compressor (HP) 18.

The primary P and secondary S flows are separated from the outlet of the blower 12 by an inter-vein casing 30 which has an edge 31 upstream and which thickens as it goes downstream to form a cavity in which a discharge system 32 is positioned from the primary stream 14 to the secondary stream 20, making it possible to deflect part of the primary stream P flowing in the primary stream 14 downstream of the BP compressor 16 so that it joins the secondary stream S. The inner cavity of the inter-vein casing 30 is formed by three enclosures 34, 36, 38 succeeding each other from upstream to downstream, and comprises a first enclosure 34 located upstream of the arms 22, a second enclosure 36 arranged substantially at the level arms 22 and a third enclosure 38 located downstream of arms 22.

In the second enclosure 36 is a discharge door 40 of the discharge system 32. The door 40 is arranged in the inter-vein casing 30 and it comprises a panel 42 pivotally mounted on this casing to close an opening 42 for gas passage of said inter-vein casing 30 or to discover said opening at a determined opening angle. On the casing 30, the door 40 is generally mounted on the side of the secondary flow stream 20.

As illustrated in more detail in FIG. 2, such a door 40 generally comprises a pivoting panel 44 which has an edge 46 articulated by a hinge hinge 48 along a first axis A1 relative to a plate 50 fixed to the inter-housing. veins 30. As illustrated in more detail in FIG. 3, the panel 44 has a face 52 facing the secondary flow vein from which protrudes a yoke 54 receiving an axis of articulation 56 parallel to the first axis A1 which is connected to a generally complex actuation mechanism 58, in turn driven by an actuator. The mechanism 58 comprises for example a connecting rod 60 coupled to the axis 56 and to a return lever 62 articulated on the plate 50 around a radial axis R1, said return lever itself being coupled to a yoke 64 actuated by the actuator (not shown in Figure 3).

As illustrated in FIG. 1, the actuator 66 is for example housed in the third enclosure 38 and it comprises a rod 68 linked to the yoke 64 which has been shown in FIG. 3.

The complexity of the mechanism 58 makes it easy to imagine that it is difficult to instrument the door 40 in situ, because of the reduced space around this door 40. In addition, it is not conceivable to immobilize a turbomachine operational only for testing purposes.

As illustrated in FIG. 8, the invention overcomes these drawbacks by proposing a measurement bench 70 making it possible to measure operating parameters of the door 40.

The discharge door 40 is identical to that used in the turbomachine 10. As illustrated in FIG. 4, it also includes a pivoting panel 44 and a seal 72 bordering said panel 44.

According to the invention, the measurement bench 70 firstly comprises a casing 74 which has a wall 76 which delimits an interior chamber 77 supplied with air under pressure G via an inlet mouth 78 and in which an opening 42 for gas passage is formed.

The casing 74 is not necessarily identical to an authentic turbomachine casing, it suffices for it to reproduce the pressure characteristics prevailing inside the interior chamber 77.

As illustrated in FIG. 6, the opening 42 is formed in an upper part of the wall 76 and it comprises a seat 82 on which the panel 44 of the door 40 is intended to come to apply, as shown in the FIG. 5, to close the opening 42. The seat 82 is in particular intended to receive the gasket 72 which is configured to be crushed between the seat 82 and the panel 44, as shown in FIG. 4.

The wall 76 delimits the housing 74 and it comprises, in an upper part 83, a hinge 48 of first axis A1 by means of which the panel 44 of the door 40 is articulated on the housing 74 between a position for closing the opening 42 , as shown in FIGS. 4, 7 and 8, and a position for releasing the opening 42.

The measuring bench 70 also includes a movement transmission member 84 oriented in a first direction D1 which is perpendicular to the first axis A1. This movement transmission member 84 is pivotally mounted on the casing 74 around a second axis A2 parallel to the first axis A1. It has a first end 86 articulated on the panel 44 and an opposite second end 88 which is intended to be urged so that, in turn, the first end 86 in turn urges the panel 44 of the door 40.

To this end, the measuring bench 70 includes a biasing element 90, oriented in a second direction R2 perpendicular to the first axis A1 and to the movement transmission member 84. The biasing element has a first end 92 connected to the casing 74 and an opposite second end 95 which is articulated on the second end 88 of the movement transmission member 84.

Finally, the measuring bench 70 comprises at least one means for measuring a parameter representative of the stress exerted by the stressing element 90.

This measurement means differs according to the stress that you want to measure.

According to a first embodiment of the measurement bench 70 which has been shown in FIGS. 4 and 7, it is configured to measure a leakage rate leaving the chamber 77 as a function of the opening of the door 40.

To this end, the biasing element 90 is configured to be at least deployable in its direction of orientation R2, here vertical in FIG. 7.

In this configuration, as illustrated in FIGS. 4 and 7, the biasing element 90 comprises at least one deployable turnbuckle 94 comprising a fastening yoke 96 which is capable of being connected to the casing 74 by an axis 98, a first threaded rod 100 which is integral with the attachment yoke 94, a tubular sleeve 102 comprising at its ends two threads oriented in opposite directions to one another, and a second threaded rod 104 which is threaded in opposite direction to the first threaded rod 100 and which is integral with the second end 95. The second end 95 has a third hinge pin 106 with the second end 88 of the movement transmission member 84, which is in the direction A3 parallel to the axis A1. The axis 98 allowing the attachment of the attachment yoke 95 is for example carried by a bracket 99 of the casing 74, which also comprises an arm 101 crossed by a bore 103 intended to receive receiving the socket 102 to hold the turnbuckle 94.

The tubular sleeve 102 receives the two threaded rods 100 and 104. The rotation of the tubular sleeve 102 in one direction or the other in the arm 101 allows the threaded rods 102, 104 to be brought together or apart from one another. 'other in the second direction R2 and therefore to deploy or restrict the biasing element 90 in the second direction R2.

The deployable turnbuckle 94 also comprises blocking locknuts 108, which are received on the threaded rods 100 and 104, and which allow the first and second threaded rods 100 and 104 to be blocked against the sleeve 102.

The movement transmission member 84 is, in turn, shaped as a lever which is pivotally mounted on the casing 74 by means of a pivot 120 materializing the second axis A2 and of which the first and second opposite ends 86, 88 have oblong slots 122, 124 rectilinear aligned with each other. These slots 124, 122 respectively receive in sliding the third articulation axis 106 carried by the second end of the biasing element 90 and, conversely, the fourth axis 56, of direction A4 parallel to the first axis A1, which is carried by the yoke 54 which projects from the panel 44 of the door 40 to ensure the connection of the movement transmission member 84 to the door 40. For example, the length of the oblong lights 122, 124 is between 10 and 20mm and the width of these lights is between 5 and 10mm.

The sliding of the axes 106, 56 in the slots 122, 124 makes it possible to transform the axial movement in the second direction R2 of the biasing element 90 into a rotational movement of the movement transmitting member 84 around its pivot 120 , and the rotational movement of the movement transmitting member 84 around its pivot 120 in rotational movement of the door around its axis A1.

Note that the lever forming the motion transmission member 84 is elongated, but it could take another shape, for example a V shape, provided that the oblong slots 122, 124 rectilinear are aligned with each other .

It will therefore be understood that the rotation of the sleeve 102 makes it possible to move the second end 95 and therefore to urge the movement transmission member 84 so that it in turn urges the panel 44 of the door 40. By a simple geometric conversion, it is thus possible to know an opening angle of the panel 44 as a function of the displacement of the second end 95 of the biasing element 90. Consequently, it is possible to measure the leak rate of the chamber 77 by as a function of the displacement of the second end 95 and of deducing therefrom a relationship between the leakage rate of the chamber 77 and the opening angle of the panel 44 of the door 40.

To this end, the bench 70 comprises a first means 110 for measuring the deployment of the means 90 for biasing during its travel and a second means for measuring (not shown) a leakage rate of the pressurized air leaving the inner chamber 77 of the housing 74.

Generally, the interior chamber 77 of the housing 74 is configured to remain sealed and under pressure as long as the door 40 is closed, in other words, it is configured so that the only authorized leak rate is that occurring at opening the door 40. The second measurement means can take any form known in the art. In practice, it may be a flow meter known from the state of the art, which is attached to the mouth 78.

The first means 110 for measuring the deployment of the biasing means 90 during its travel is preferably placed on the turnbuckle 94. It comprises a flange 112 with an axis corresponding to that of the biasing means 90 which includes a thread through which the second threaded rod 104 and which is immobilized on the second rod 104 threaded by a lock nut 114, and a slider 116 extending perpendicularly to the axis of said flange. The axial displacement of the cursor 116 parallel to the direction of the turnbuckle, that is to say vertically in FIG. 7, is equal to the axial deployment of the turnbuckle 94 in the same direction. The measurement of this displacement can be carried out visually, or using an electronic measuring means 118 connected to the cursor 116, as illustrated in FIG. 7.

In this configuration, as illustrated in FIG. 9, a method of measuring a leakage rate in operation of a door 40 for discharging turbomachine gas as a function of its angular opening can be carried out by means of the measurement bench 70 previously described. It comprises a first step ET1 during which the fixing bracket 96 of the turnbuckle is fixed directly to the axis 98 of the housing 74. Then, during a second step ET2, the locknuts 108 of the turnbuckle are released. 94. Then, during a third step ET3, the sleeve 102 of the turnbuckle 94 is operated to cause a determined axial expansion of the turnbuckle 94 and consequently a determined angular opening of the door 40. The locknuts 108 are then blocked of turnbuckle 94 in step ET4. Finally, during a fifth step ET5, the leakage rate associated with the angular opening is measured, using the second measuring means.

According to a second embodiment of the measurement bench 70 which has been shown in FIG. 8, it is configured to measure a force for closing the door 40, the closing of the door being considered to be obtained as soon as its seal 72 is sufficiently compressed on its seat 82 so that the leakage rate is zero. It is for example possible to characterize the watertight closing of the door 40 by the absence of leakage rate 40.

To this end, the biasing element 90 is configured to be retractable in the second direction R2. As illustrated in FIG. 8, it comprises for this purpose, in addition to the turnbuckle 94, a retractable traction means 130 and a third force measurement means 132, which are arranged in series between the attachment yoke 96 of the turnbuckle and the housing 74. The retractable traction means 130 and the third force measurement means 132 are not fixed directly to the housing 74, but are in terms of force path. In the second configuration, the casing 74 in fact rests on a support 134 which includes a second bracket 136 to which all of the retractable traction means 130 and of the third force measurement means 132 are attached. The attachment yoke 96 of the turnbuckle is attached to the other end of the assembly of the retractable traction means 130 and of the third force measurement means 132.

The retractable traction means 130 comprises for example a screw tensioner known per se from the state of the art and the third force measurement means 132 consists of a dynamometer. This configuration is not limiting for the invention, in fact, the third means 132 of force measurement could be a strain gauge or any other means of force measurement.

It will be noted that the retractable traction means 130 and the third force measurement means 132 can advantageously be reversed without changing the efficiency of the assembly.

The bench 70 also includes an adjustable stop means 138 of the movement transmission member 84, this stop being associated with a sealed closing position of the door 40.

Advantageously, as illustrated in FIG. 8, the casing 74 includes a support 140 which projects outwards from its wall 76, which carries the pivot 120 materializing the second pivot axis A2 of pivoting of the lever 84, and which comprises a wall 142 of the support which extends above the lever 84 on the side of the axial biasing element 90 and which is crossed by a contact screw, capable of coming into contact with the lever 84 to form the third stop means 138 .

Preferably, the support 140 comprises a cavity 144 which is crossed by the lever 84. The pivot 120 is mounted internally to this cavity.

In this configuration, as illustrated in FIG. 10, a method for measuring a force for closing a door 40 for discharging gas from a turbomachine can be carried out by means of the measurement bench 70 previously described. This process comprises a first step ΕΓ1 during which the attachment yoke 96 of the turnbuckle 94 is fixed by means of the dynamometer 132 and the screw tensioner 130 mounted in series. Then, during a second step ΕΓ2, the screw tensioner 130 is maneuvered to the closed position according to which compression of the gasket 72 carried by the panel 44 of the door 40 seals between the door 40 and the opening 42 for the passage of gases. This position is then considered as the closed position of the door 40. During a third step ΕΓ3 the lever 84 is blocked with the stop screw 138. Finally, during a fourth step ΕΓ4, we measure at l using the dynamometer 132 the tensile force exerted by the screw tensioner 130.

The measuring bench 70 therefore makes it possible to measure in a simple and effective manner the mechanical stresses, both in terms of displacement and in terms of force, which have to be exerted on the panel 44 of a discharge door 40 to ensure a efficient operation. These constraints can be used to size the actuator intended to actuate the door 40 in the turbomachine 10 to allow efficient operation of the discharge door.

Claims (10)

1. Measuring bench (70) for operating parameters of a pivoting door (40) of a turbomachine, such as a discharge door (40), comprising at least one opening (42) for gas passage, a panel ( 44) pivoting, and a seal (72) disposed between the panel (44) and the opening (42), characterized in that the measurement bench (70) comprises: - a housing (74) which has a wall which delimits an interior chamber (77) supplied with pressurized air (G) and in which the opening (42) is formed, a first axis (A1) via which the panel (44) is articulated on the casing (90) between a position for closing the opening (42) and a position for releasing the opening (42), a movement transmission member (84) oriented in a first direction (D1) perpendicular to the first axis (A1), the transmission member (84) being pivotally mounted on the casing (74) about a second axis ( A2) parallel to said first axis (A1) and comprising a first end (86) articulated on said panel (44) and a second opposite end (88), - a biasing element (90) oriented in a second direction (R2) perpendicular to the first axis (A1) and to the first direction (D1), the biasing element (90) having a first end (92) connected to the casing (74) and an opposite second end (95) articulated on said second end (88) of the transmission member (84), - At least one measuring means (110, 132) of a parameter representative of the stress exerted by said biasing element (90). 2. Measuring bench (70) according to the preceding claim, characterized in that the biasing element (90) is configured to be deployable in the second direction (R2), and in that it comprises a first measuring means (110) of the deployment of the biasing element and in that the measurement bench (70) comprises a second means for measuring a leakage rate of the pressurized air leaving the interior chamber (77) of the housing ( 74). 3. Measuring bench (70) according to the preceding claim, characterized in that the biasing element (90) comprises at least one deployable turnbuckle (94) comprising: - an attachment yoke (96) capable of being connected to the casing (74), - a first threaded rod (100) integral with the attachment yoke (96), the second end (95) of the biasing element, comprising a third articulation axis (106) at the second end (88) of the transmission member (84), a second threaded rod (104), threaded in the opposite direction to the first threaded rod (100), and integral with said second end (95), a tubular sleeve (102) comprising at its ends two internal threads receiving the first and second threaded rods (100, 104), - Locking locknuts (108) of the first and second threaded rods (100, 104) against the sleeve (102). 4. Measuring bench (70) according to the preceding claim, characterized in that the first measuring means (110) is placed on the turnbuckle (94) and comprises a flange (112) which has a thread crossed by the second threaded rod (104) and which is immobilized on said second threaded rod (104) by a lock nut (114), and a slider (116) extending perpendicularly to an axis of said collar (112), the movement of said cursor (116) along said axis defining the deployment of the turnbuckle (94). 5. Measuring bench (70) according to one of claims 3 or 4, characterized in that the biasing element (90) is configured to be further retractable in the second direction (R2), and in that it further comprises a retractable traction means (130) and a third force measurement means (132), which are arranged in series between the attachment yoke (95) of the turnbuckle (94) and the casing (74) , and in that said measurement bench (70) comprises an adjustable stop means (138) of the transmission member (84) associated with a sealed closing position of the door (40). 6. Measuring bench (70) according to the preceding claim, characterized in that the retractable traction means (130) comprises a screw tensioner and in that the third force measurement means (132) comprises a dynamometer. 7. Measuring bench (70) according to one of claims 3 to 6, characterized in that the transmission member (84) is a lever which is pivotally mounted on the casing (74) via the second axis (A2) and whose first and second opposite ends (86, 88) comprise oblong slots (122, 124) rectilinear aligned with each other which respectively receive in sliding: the third articulation axis (106) carried by the second end (95) of the biasing element (94), - A fourth axis (56), parallel to the first axis (A1) which is carried by a yoke (54) which projects from the panel (44) of the door (40). 8. Measuring bench (70) according to the preceding claim, characterized in that the casing (74) comprises a support (140) which projects outwards from its wall (76), which carries the second axis (A2) for pivoting the lever, and at least one wall (142) of said support (140) which extends above the lever on the side of the axial biasing element (90) and which is crossed by a contact screw capable of coming into contact with the lever and forming the third stop means (138). 9. A method of measuring a leakage flow in operation of a discharge door (40) for turbomachine gas as a function of its angular opening by means of a measurement bench (70) according to claim 4, characterized in what it includes: a first step (ET1) during which the attachment yoke (96) of the turnbuckle (94) is fixed to the casing (74), - at least a second step (ET2) of unlocking the lock nuts (108) of the turnbuckle (94), - at least a third step (ET3) during which the sleeve (102) of the turnbuckle (94) is operated to cause a determined axial deployment of said turnbuckle (94) and consequently a determined angular opening of the door (40), - at least a fourth step (ET4) for blocking the locknuts (108) of the turnbuckle (94), - At least a fifth step (ET5) of measuring a leakage rate associated with said determined angular opening, using the second measuring means. 10. A method of measuring a force for closing a door (40) for discharging turbomachine gas by means of a measuring bench (70) according to any one of claims 6 to 8, characterized in that 'it comprises : - A first step (ΕΓ1) during which the attachment yoke (96) of the turnbuckle (94) is fixed to the casing by means of a dynamometer (132) and the screw tensioner (130) mounted in series , - a second step (ΕΓ2) during which the screw tensioner (130) is operated until the closed position according to which compression of the seal (72) of the door (40) seals between the door ( 40) and the opening (42) for the passage of gases, - a third step (ΕΓ3) during which the lever is blocked with the stop screw (138), 5 - a fourth step (ΕΓ4) during which the tensile force exerted by the screw tensioner (130) is measured using the dynamometer (132).