EP2932077A1

EP2932077A1 - Nacelle thrust reverser and nacelle equipped with at least one reverser

Info

Publication number: EP2932077A1
Application number: EP13818282.9A
Authority: EP
Inventors: Pierre Caruel
Original assignee: Aircelle SA
Current assignee: Safran Nacelles SAS
Priority date: 2012-12-12
Filing date: 2013-12-10
Publication date: 2015-10-21
Also published as: FR2999239B1; FR2999239A1; RU2015128041A; WO2014091140A1; CN104854335A; CN104854335B; US20150260126A1; US9677502B2; CA2893633A1

Abstract

The present invention relates to a turbojet engine nacelle thrust reverser and to a nacelle equipped with at least one thrust reverser as aforementioned, said thrust reverser comprising: - at least one outer cowl (2), produced as two half-cowls (3) articulated on hinges (5), capable of translational movement from a position referred to as the closed position into at least one position referred to as open, - first actuating means (8) for actuating the translational movement of the downstream frame (18), - second actuating means (9) for actuating the rotation of each half-cowl (3), - locking/unlocking means (7) that lock/unlock the half-cowls (3) relative to one another, - thrust reversal means (13) comprising at least cascades of deflection veins (14) supported at their upstream end (15) by an upstream frame (16) and at their downstream end (17) by a downstream frame (18) and enclosed in a shroud (19) formed by a fan casing (20) and a fan cowl (11), means (21) of connection between the downstream frame (18) and the external cowl (2).

Description

Platform thrust reverser and nacelle equipped with at least one inverter

The present invention relates to a thrust reverser for a turbojet engine nacelle, as well as a nacelle for a turbojet engine incorporating a thrust reverser, according to the invention.

In multi-engine airplanes, each engine is housed in a nacelle serving as both support and engine cover.

Generally, this boat is reliquely connected to it or via a mast, either at the wing or the fuselage of the aircraft.

In addition to housing the turbojet, the nacelle can also receive different mechanical systems annexes, including a mechanical thrust reverser actuation system.

The thrust reverser is a device that directs the airflow generated by the turbojet engine to the front, allowing both to shorten the landing distance and also to limit the stress of the brakes at the undercarriages.

In general, a nacelle has a substantially tubular structure, with an air inlet upstream of the turbojet, followed by a median section intended to surround a turbojet fan, a downstream section integrating both the inversion means of thrust and surrounding the combustion chamber of the turbojet engine.

The nacelle further comprises, at its downstream end, a nozzle for ejecting the flow coming out of the turbojet engine.

The most modern technologies use turbofan engines; in these turbojets, it is generated by means of the blades of the fan, both a hot air flow called primary flow, and a cold air flow called secondary flow.

This second flow of cold air circulates outside the turbojet through an annular passage also called vein, this vein being formed between a fairing of the turbojet engine and the inner wall of the nacelle.

In this type of engine, the thrust reverser completely or partially obstruct the flow of cold air flow, to redirect this flow to the front of the nacelle.

There are several different technologies for making these thrust reversers. A particularly interesting technology because it reduces the length of the nacelle and therefore limits both the mass of the latter and its drag, is to design mobile grid thrust reversers in which the grids are housed between the housings and the hood of the fan, during a direct jet operation of the nacelle.

In this type of thrust reverser, the inversion is performed by translating the outer cover with the grids that come out of their housing and allow the redirection of airflow forward.

The present invention falls into this category of thrust reverser with movable grids.

Furthermore, there are also two main types of nacelle structures, namely a first type in which the outer cover is formed with two half-covers, of substantially semi-cylindrical shape, these two half-covers being articulated in the upper part on hinges. substantially parallel to the direction of translation of the outer cover.

The connection between the two half-covers is made by locks arranged in the lower part.

A second type of structure of the nacelle is said monoblock structure or O-structure in which the outer cover is formed of a single cylindrical part.

The present invention is in the field of nacelles of the first mentioned category, commonly called D-structure platform.

In summary, the present invention is an improvement to the D-frame pods, and mobile grid thrust reverser.

As for any type of nacelle, maintenance operations are to be provided regularly and to do this, it is necessary to access the interior of the nacelle and, for example to the turbojet engine, or to the ancillary devices including the structure internal of the inverter.

In the specific type of device in which the invention is inscribed, the access to the interior of the nacelle is achieved by unlocking the two half-covers allowing a "butterfly" opening, after having previously made a unlocking the movable grilles and the half covers.

It is understood that this double unlocking is particularly disadvantageous, on the one hand the disconnection of the mobile grids is made complicated by restricted access to the disconnection system, and, on the other hand, this double unlocking system detrimentally increases the weight of the nacelle; finally this double unlocking system also increases the dimensions of the nacelle and the associated cover.

An object of the present invention is to overcome the aforementioned drawbacks by providing a nacelle with a thrust reverser in which access to the engine is authorized by a single manual unlocking action.

Another object of the present invention is to provide a nacelle in which access to the motor can be carried out indifferently when the outer cover is translated backwards, corresponding to the indirect jet position or to the front corresponding to the direct jet position .

Another object of the present invention is to provide a nacelle in which access to the motor can be achieved when the fan cowl is fixed or closed.

Another object of the present invention is to provide a nacelle whose weight and dimensions are improved compared to the D-shaped platform, with inverter movable gates, conventionally used until now.

For this purpose, the invention relates to a thrust reverser for a turbojet engine nacelle, comprising:

at least one outer cover, made in two hinged covers hinged on hinges, movable in translation from a so-called closing position to at least one open position,

first means for actuating the downstream frame in translation,

second means for actuating in rotation each half-cover,

locking / unlocking means of the half-covers between them,

- Thrust reversal means, comprising at least deflection grids supported at their upstream ends by an upstream frame, and at their downstream end by a downstream frame, and enclosed in a casing formed by a fan casing and by a blower hood,

connecting means between the downstream frame and the outer cover, and such that, according to the invention, the connecting means of the inverter allow to maintain the connection between the outer cover and the downstream frame during the actuation of the first means of actuation in translation and to separate the outer cover of said downstream frame during the actuation of the second actuating means in rotation after unlocking said half-covers, so as to ensure access to the interior of the nacelle in a single manual unlocking operation. The invention also relates to a nacelle or aircraft turbojet, comprising at least one thrust reverser according to the invention.

Other characteristics, objects and advantages of the present invention will become apparent on reading the following detailed description of an exemplary embodiment given by way of nonlimiting example and with reference to the appended drawings among which:

- Figure 1 shows a schematic perspective view of a turbojet engine nacelle made according to the invention in a maintenance position;

- Figure 2 is a sectional view of the nacelle shown in Figure 1 and centered on the median part of the nacelle at the mobile gates;

- Figure 3 is a sectional view of the nacelle as shown in Figure 2, the nacelle being deposited in reverse jet;

FIG. 4 represents an enlarged view of the embodiment detail denoted I in FIG. 2,

- Figure 5 shows, in a perspective view, the connection means in the disconnected position.

Referring to Figure 1 showing a nacelle 1 turbojet (not shown), arranged in maintenance configuration with an outer cover 2 made with two half-covers 3, connected to the upper part of the nacelle 4, this upper part 4 being intended to serve as a link interface with a reactor mast not shown in the accompanying drawings.

We see in this figure that it is indeed a nacelle 1 D-type structure, with two dem i-caps 3 hinged in their part superior by means of hinges 5 and having at their lower end 6 locking / unlocking means of the half-covers 3 between them.

The downstream frame can translate backwards by means of the first actuating means 8 connected thereto.

The outer cover 2 can translate backwards, and also when the outer cover 2 is unlocked, second actuating means 9 allow a rotational movement of each half-cover 3.

This figure 1 also shows the fan 10 and the fan cover 1 1.

Referring now more particularly to Figures 2 and 3, which shows more in detail different parts of the nacelle 1, and in particular a thrust reverser 12, said nacelle 1 being in the direct jet position in Figure 2, and reverse jet position in Figure 3.

As shown in FIG. 2, the thrust reverser 12 comprises reversing means 13, with deflection grids 14.

These deflection grids 14 are supported at their upstream end 15 by an upstream frame 16 and at their downstream end 17 by a downstream frame 18.

In an alternative embodiment of the invention, the upstream frame 16 simply ensures the connection of the deflection grids 14 between them.

In the direct jet configuration, it can be seen that these deflection gratings 14 are closed in an envelope 19 formed by the fan casing 20 and the fan casing 11.

The thrust reversal means 1 3 further comprise connecting means 21 between the downstream frame 18 and the outer cover 2.

As can be seen by referring this time mainly to FIG. 3, the connecting means 21 make it possible to maintain the connection between the outer cover 2 and the downstream frame 18, upon actuation of the first actuating means 8.

FIG. 3 thus shows that the first actuating means

8 have driven the downstream frame 1 8, and deflection grill 1 4 which read i are integral rearward and that this translation to the rear of this downstream frame 18 has caused the displacement in the same direction of the outer cover 2 ..

Referring this time more particularly to FIG. 4, the part noted in capital letters in FIG. 2 is shown in detail. This detail makes it possible to visualize more precisely the connection means 21 between the downstream frame 18, integral with the deflection gratings 14, and the outer cover 2 via the inter-panel frame 22.

According to the preferred embodiment, illustrated in Figures 1 to 4, the connecting means 21 comprise a groove 23 cooperating with a knife 24.

The groove 23 is integral with the downstream frame 18, while the knife 24 is secured to the outer cover 2 via the interplanar frame 22.

At this level, it is important to note that eventually, in another embodiment, the groove 23 could be solitary of the outer cover 2, while the knife 24 would be secured to the downstream frame 18.

It is also conceivable to create a knife 24 whose geometry allows direct attachment to the outer cover 2.

Finally, according to another variant embodiment, it will be possible to produce the downstream frame 18 and the groove 23 in one and the same piece.

As shown in FIG. 4, it can be seen that the end 24 of the knife is engaged in the groove 23, so that when the first actuating means 8 are activated, the deflection grids 14 and the downstream frame 18 pass from the 2 to that of FIG. 3, that is to say it comes in translation on the rear, which in turn drives the groove 23 which, cooperating with the knife 24, also causes and consequently also displaces backward. the outer cover 2.

When the first actuating means 8 are activated to return to the direct jet position, that is to say to move from the position illustrated in FIG. 3 to that of FIG. 2, the drive is effected of the same that is to say that the deflection grids 14 and the downstream frame 1 8 are driven forwardly in direction of the hood of the fan 1 1 inside their envelope 19., moving by the same the groove 23 which cooperates with the knife 24 and reposition the outer cover 2 to its initial position.

Referring again to FIG. 1, it can be seen that the two half-covers 3 are partially raised allowing access to the turbojet engine and, furthermore, it can be seen that the deflection grids 14 and the downstream frame 18 are not visible. more connected to the external cover 2. To do this, the operator actuates the second actuating means 9, after having previously unlocked half-covers 3 from the locking / unlocking means 7.

Unlocking the half-covers 3 allows the latter to pivot about the axis formed by their respective hinges 5.

The second actuating means 9 allow the rotation of each half-cover 3, ie their raising for the access operations inside the platform 1 or when the maintenance operations are performed, their lowering in to achieve again locking the half-covers 3 between them.

Note that for this purpose, the second rotation actuating means 9 comprise opening control cylinders 31, these control cylinders 31 being, on the one hand, attached on one side to either the deflection gratings 14, or in one variant of the downstream frame 18, and secondly, on the other side, to an integral element of the outer cover 2.

When the nacelle is intended to house small engines, the rotation of the half-covers 3 can be performed manually. For this purpose, a locking rod will be extended and locked manually to maintain the assembly in the open position.

Referring now to Figure 5, showing the connection means 21 in the disconnected position, it is understood that when the outer cover 2 or more exactly when the half-covers 3 are rotated, the knife 24, ideal floor of the hood outer, also rotates and the knife head 24 out of the groove 23.

The disconnection between the outer cover 2 and the downstream frame 1 8 is thus automatically obtained during the actuation of the second actuating means 9, thanks to the particular structure of the connecting means 21.

As a result, it is no longer necessary, as in the state of the art, to perform two manual unlocking operations, namely one at the level of the deflection gratings 14 and the second at the level of the half-covers 3.

This structure of the connecting means 21 is therefore particularly advantageous with respect to the existing solutions in the fields of D-type mobile grid-type nacelles, since it ensures both a reliable drive in translation between the deflection gates 14 and the hood external 2, while ensuring a disconnection between these elements, when the second actuating means 9 come up the half-covers 3.

Another advantage of this structure is that the disengagement of the knife 24 with respect to the groove 23 can be achieved regardless of the position of the outer cover 2 relative to the casing of the fan 20, that is to say when the nacelle 1 is in the direct jet position, inverted jet or for any intermediate position between these two extreme positions.

Referring again to FIG. 4, it can be seen that the groove 23 is connected to a joining piece 25. This joining piece 25 is intended to ensure aerodynamic continuity with the deflection edge 26 of the fan casing 20.

Advantageously, it can be seen that this connecting piece 25, which preferably has a substantially V-shaped profile, also bears, on its inner face 27, a seal 28. This seal 28 is in contact with the deflection edge 26 of the fan casing, preventing the creation of a secondary flow between the fan casing and the front of the flaps, when the pod 1 is in the direct jet position. Advantageously, the seal 28 comprises a base 29 secured to the joining piece 25, as well as a hollow tubular portion 30 coming into contact with the deflection edge 26, the hollow tubular portion 30 allowing the joint to be crushed. on the wall of the deflection edge 26, thereby improving the sealing of this zone.

According to an advantageous embodiment, it is also provided, at one end of the deflection grids 14 a cooperation with the engine mast of the nacelle. The end of the grid 14 allows a sliding of the grid along the latter to collaborate with a motor suspension positioned at deflection gilles 14. This cooperation is obtained, advantageously, using a rail in U allowing the recovery of the vertical forces applied to said end of the grids.

Thanks to the present invention, there is a nacelle 1 equipped with a thrust reverser 12, in which it is not necessary to have the security and locking elements between the deflection grids 14 and other sets fixed nacelle 1, allowing easy access to the engine, a weight and a reduced volume for the nacelle 1, while reliably ensuring the passage of direct jet reverse jet and vice versa.

Of course, the present invention is not limited to the described embodiment of this thrust reverser and this nacelle, others characteristics and advantages of the invention will become clear to the person skilled in the art, while remaining within the scope defined by the claims below.

Claims

A thrust reverser for a turbojet engine nacelle, comprising:

at least one outer cover (2), made in two half-covers (3) articulated on hinges (5), movable in translation from a so-called closing position to at least one so-called opening position,

first actuating means (8) in translation of a downstream frame (18),

second actuating means (9) rotating each half-cover (3),

locking / unlocking means (7) of the half-covers (3) between them,

- thrust reversing means (13), comprising at least deflection grids (14) supported at their upstream end (15) by an upstream frame (16) and at their downstream end (17) by a downstream frame ( 18) and enclosed in an envelope (19) formed by a fan casing (20) and by a fan cowl (11), connecting means (21) between the downstream frame (18) and the outer cowl (2) ,

said inverter being characterized in that the connecting means (21) make it possible to maintain the connection between the outer cover (2) and the downstream frame (18), when the first actuating means (8) are actuated in translation and detaching the outer cover (2) from said downstream frame (18) during the actuation of the second actuating means (9) in rotation after unlocking said half-covers (3), so as to ensure access to the inside the platform (1) in a single manual unlocking operation.

2. thrust reverser according to claim 1, wherein the connecting means (21) comprise a groove (23) integral with the downstream frame (18) or the outer cover (2) and a knife (24) secured respectively to the outer cover (2) or the downstream frame (18), the groove (23) and the knife (24) cooperating so as to ensure their drive during a movement in translation, and their separation in a rotational movement of the knife (24) relative to the groove (23).

3. thrust reverser according to claim 2, wherein the groove (23) is integral with the downstream frame (18) and the knife (24) is integral with the outer cover (2).

4. thrust reverser according to claim 3, wherein the downstream frame (18) and the groove (23) form a single piece.

A thrust reverser according to one or more of claims 3 or 4, wherein the groove (23) is integral with a junction piece (25) providing aerodynamic continuity with the deflection edge (26). carried by the fan casing (20).

The thrust reverser according to claim 5, wherein the junction piece (25) bears on its inner face (27) a seal (28), said seal (28) being in contact with said deflection edge ( 26) of the fan casing (20).

A thrust reverser according to claim 6, wherein the seal (28) has a hollow tubular portion (30) for crushing the seal (28) on the wall of the deflection edge (26). .

8. thrust reverser according to any one of claims 3 to 7, wherein the knife (24) is fixed on an interpanneau frame (22), integral with the outer cover (2).

A thrust reverser according to any one of the preceding claims, wherein the second actuating means (9) comprise actuators (31) for controlling the opening attached on the one hand to the deflection grids (14) or downstream frame (18), and secondly to the outer cover (2).

10. A thrust reverser according to any one of the preceding claims wherein one end of the grids cooperates with the reactor mast allowing a sliding of the grid along the latter to collaborate with a motor suspension positioned at deflection gilles ( 14)

11. Nacelle for turbojet, characterized in that it comprises at least one thrust reverser (12), according to any preceding claim.