WO2013014350A1

WO2013014350A1 - Rear frame for a deflection cascade-type thrust reverser structure for a turbo jet engine nacelle

Info

Publication number: WO2013014350A1
Application number: PCT/FR2012/051502
Authority: WO
Inventors: Florent Bouillon; Laurent Dubois; Alexandre Bellanger; Bertrand Desjoyeaux
Original assignee: Aircelle
Priority date: 2011-07-27
Filing date: 2012-06-29
Publication date: 2013-01-31
Also published as: FR2978497B1; FR2978497A1

Abstract

Rear frame (1) for a deflection cascade-type thrust reverser structure for a turbo jet engine nacelle, said rear frame (1) being intended to support a downstream edge of one or more cascade(s) of deflection vanes and comprising at least an arcuate body (10) made of composite material and having two free ends (11) secured to two respective articulation pieces (13) for a pivoting connection of said rear frame (1) to at least one bearing structure, notable in that the articulation pieces (13) are made as one piece with the arcuate body (10) from composite material. The present invention finds an application in the field of nacelles for aircraft jet engines.

Description

REAR FRAME FOR A THRUST INVERSION STRUCTURE WITH DEVIATION GRIDS OF A TURBOJET NACELLE

The present invention relates to a rear frame for a thrust reversal structure with deflection grids of a turbojet engine nacelle.

The invention also relates to a thrust reversal structure with deflection grids and a nacelle comprising such a rear frame.

An aircraft is driven by several turbojets each housed in a nacelle also housing a set of ancillary actuators related to its operation and providing various functions when the turbojet engine is in operation or stopped. These ancillary actuating devices comprise in particular a mechanical thrust reversal system.

More specifically, a nacelle generally has a tubular structure comprising an air inlet upstream of the turbojet engine, a median section intended to surround a fan of the turbojet engine, a downstream section housing the thrust reversal means and intended to surround the engine room. combustion of the turbojet, and is generally terminated by an ejection nozzle whose output is located downstream of the turbojet engine.

Modern nacelles are intended to house a turbofan engine capable of generating through the blades of the rotating fan a flow of hot air (also called primary flow) from the combustion chamber of the turbojet engine, and a flow of cold air (secondary flow) flowing outside the turbojet through an annular channel, also called vein, formed between a fairing of the turbojet engine and an inner wall of the nacelle. The two air streams are ejected from the turbojet engine by the rear of the nacelle.

The role of a thrust reverser is, during the landing of an aircraft, to improve the braking capacity thereof by redirecting forward at least a portion of the thrust generated by the turbojet engine. In this phase, the inverter obstructs the annular channel of the cold air flow and directs the latter towards the front of the nacelle, thereby generating a counter-thrust which is added to the braking of the wheels of the aircraft .

The means used to achieve this reorientation of the cold air flow vary according to the type of inverter. However, in all cases, the structure of an inverter comprises movable covers moved between, on the one hand, an extended position in which they open in the nacelle a passage for the deflected flow, and on the other hand, a retracted position in which they close this passage. These covers can perform a deflection function or simply activation other means of deflection.

In the case of a deflection thrust reversal structure, also known as a cascade reverser, the reorientation of the air flow is performed by deflection grids (or thrust reversal grids). ) associated with inversion flaps, the hood having a simple sliding function to discover or cover the deflection grids. The inversion flaps form locking doors activated by the sliding of the cowling generally generating a closure of the annular channel downstream of the grids so as to optimize the reorientation of the cold air flow.

Conventionally, the thrust reversal structure is supported by a bearing structure consisting of an upper support beam, said upper beam or beam 12H, which is itself supported by a support pole of the nacelle.

The bearing structure may also comprise, in addition to the upper beam, a lower support beam, called lower beam or beam 6H, which is connected to the upper beam via an internal structure which surrounds the turbojet engine.

Two main types of thrust reversal structure are conceivable:

thrust reversal structure of the "O-duct" or "C-duct" type, that is to say made from a single piece completely surrounding the turbojet engine;

- Thrust reversal structure of the type "D-duct", that is to say comprising two half-parts joined together around the turbojet engine, the half-structures then generally 6H beams.

Generally, and as illustrated in FIG. 1, the deflection grilles (not shown) are attached, on the one hand, upstream to the turbojet engine casing and to the median section of the nacelle by means of a front frame 7 and, on the other hand, downstream from the supporting structure 8 by means of a rear frame 9. Thus, the or each deflection grid has an upstream portion (sometimes called the front part) fixed on the front frame 7 and an opposite downstream part (sometimes referred to as the rear part) fixed on the rear frame 9.

The rear frame 9 thus serves to support the downstream edge of the deflection grids, the upstream edge of these deflection grids resting on the front frame 7; the use of such a rear frame is also already known from the patent application FR 2 922 958 A1 filed by the Applicant.

Depending on the type of the thrust reversal structure ("O-duct" type or "D-duct" type), the rear frame 9 is made:

or in the form of a single piece with an almost circular arched body extending from one side to the other of the upper beam;

- Or in the form of two parts (called half frames) each having a semi-circular arched body extending on either side of the vertical plane of symmetry of the inversion structure, the upper beam to the beam lower.

Conventionally, the rear frame 9 is connected either to the upper beam or to the upper beam and to the lower beam, by means of ball-type connections, that is to say allowing three degrees of freedom, in particular to to cash the various deformations intervening in operation.

Thus, in the case of a rear frame made of a single piece, it is conventional to provide, on each of the two free ends of the arched body, a hinge piece for a pivotal attachment of the rear frame on the upper beam.

As illustrated in Figures 1 and 2, in the case of a rear frame 9 consisting of two half frames, it is also conventional to provide, on each of the two free ends (upper end 91 and lower end 92) of the arcuate body 90 of each half-frame, a hinge piece 93, 94 for a pivoting attachment of the rear frame 9 on the upper beam 81 and the lower beam 82. Thus, the hinge piece 93 attached to the upper end 91 of the body arcuate 90 is pivotally mounted on a yoke 95 fixed to the upper beam 81, while the hinge piece 94 fixed to the lower end 92 of the arcuate body 90 is pivotally mounted on a yoke 96 fixed to the lower beam 82 .

As can be seen in FIG. 2, when the or each arcuate body 90 of the rear frame 9 is made of a composite material, such as, for example, carbon fibers associated with an epoxy resin, it is known to produce the hinge parts 93, 94 in the form of metal hardware and to report these hinge parts 93, 94 on both ends 91, 92 of the arcuate body 90 by bolting, by means of screw / bolt assemblies 97.

Making a rear frame with an arched composite material body and metal hardware bolted to the arched body has many drawbacks, the main ones are the extra weight and space induced by the metal fittings, not to mention the complexity of such framework that imposes bolting steps of expensive fittings in time.

The present invention aims to simplify and lighten the architecture of rear frames for thrust reversal structure with deflection grids.

For this purpose, it proposes a rear frame for a thrust reversal structure with deflection grids of a turbojet engine nacelle, said rear frame being intended to support a downstream edge of one or more deflection grids and comprising at least an arched body made of composite material and having two free ends integral with two respective hinge parts for a pivotal attachment of said rear frame on at least one supporting structure, remarkable in that the hinge parts are made in one piece with the arched body made of composite material.

Thus, the invention proposes to form the hinge parts in one piece with the composite material forming the arcuate body of the rear frame, and thus to dispense with the metal fittings of the state of the art.

In a particular embodiment, the arcuate body defines a so-called curvature plane and comprises:

an arched main wall extending in said plane of curvature and having two arcuate edges of distinct radii of curvature; and

- At least one arcuate side wing projecting from at least one arcuate edge of said central wall, in particular perpendicular to said main wall.

The curvature plane substantially corresponds to the plane in which is inscribed or includes the arched body. The lateral wing or wings, which form the strapping of the rear frame, may extend perpendicularly to the main wall or not.

According to one feature, the arcuate body has two opposed arcuate side wings projecting from the respective arcuate edges of the main wall. According to another characteristic, the arcuate body comprises at least one reinforcing rib extending between the lateral wings and secured to the main wall.

According to other advantageous features of the invention, four forms can be envisaged:

- The lateral wings project on the same side of the main wall, so that the arcuate body has a radial section in the general shape of "U";

- The lateral wings project on the same side of the main wall and are interconnected by a secondary wall substantially parallel to the main wall, so that the arcuate body has a radial section in the general shape of "D";

- The lateral wings project from both sides of the main wall, so that the arcuate body has a radial section in the general shape of "H"; - The lateral wings project from both sides of the main wall and are interconnected by a secondary wall substantially parallel to the main wall.

Advantageously, the hinge parts each comprise at least one plate in which is formed at least one through hole.

This through hole is advantageously intended to receive a ball joint to ensure a ball joint connection with the carrier structure.

Each hinge piece may comprise a single plate and thus form a simple male hinge clevis, or comprise two parallel plates and thus a double male hinge yoke.

According to a possibility of the invention, the plates of the articulation pieces come in the extension of the main wall and are coplanar with said main wall.

Thus, the plates of the hinge parts are integrated in the plane of the main wall, which corresponds to the shape to meet the angles of rotation and proximity anchors. However, the plates of the articulation parts could be implanted according to other orientations, not coplanar with the main wall, the frame operating mainly in tension.

According to another possibility of the invention, the rear frame comprises tight metal sleeves inside the orifices of the articulation parts. Thus, the ball joints can be installed in the sockets previously installed in the composite material, to facilitate the possible replacement of the ball joints.

The present invention also relates to a deflection gate thrust reversal structure for a turbojet engine nacelle, comprising at least one deflection grid having a downstream edge supported by a rear frame according to the invention.

The invention also relates to a turbojet engine nacelle comprising a thrust reversal structure according to the invention and at least one bearing structure on which are articulated the hinge parts of the rear frame for pivotal attachment of said rear frame.

Thus, the hinge parts are either hinged together on an upper beam (or beam 12H), or articulated respectively on an upper beam and a lower beam (or beam 6H).

Other characteristics and advantages of the present invention will appear on reading the detailed description below, of an example of non-limiting implementation, with reference to the appended figures in which:

- Figure 1, already commented, is a perspective view of a turbojet nacelle part incorporating a conventional rear frame;

- Figure 2, already commented, is a schematic perspective view and zoomed of the upper and lower ends of the rear frame of Figure 1;

- Figure 3 is a schematic perspective view of a rear half frame for a rear frame according to the invention;

FIG. 4 is a schematic perspective and zoomed view of the upper end of the rear half-frame of FIG. 3;

- Figure 5 is a schematic perspective and zoomed view of the upper end of a rear half frame for a first rear frame variant according to the invention;

- Figure 6 is a schematic perspective and zoomed view of the upper end of a rear half frame for a second rear frame variant according to the invention.

The following description shows a rear frame 1 for a thrust reversal structure with deflection gates of a turbojet engine nacelle, where: - The nacelle comprises a bearing structure comprising an upper beam, said beam 12H, and a lower beam, said beam 6H; and

the thrust reversal structure is of the "D-duct" type.

In this situation, the rear frame 1 comprises two half-frames having an upper end 1 1 and lower end 12 respectively mounted on the upper beam and the lower beam, such a half frame being illustrated in Figure 3 with the reference numeral 1.

Each half frame 1 is made of a single piece of composite material, and this half frame 1 monobloc comprises:

an arched body 10 of semi-cylindrical shape, defining a plane of curvature and having the two free ends 11, 12 mentioned above; and

- Two hinge parts 13, 14 formed on the two free ends 1 1, 12 respectively, for a pivotal attachment of the rear half frame 1 on the respective upper and lower beams.

Thus, the articulation piece 13 secured to the upper end

1 1 of the arcuate body 10 is pivotally mounted on the upper beam, while the hinge piece 14 integral with the lower end 12 of the arcuate body 10 is pivotally mounted on the lower beam.

The composite material used may, by way of non-limiting example, be of the composite fiberglass material type pre-impregnated with a thermosetting resin, such as an epoxy resin, LRI composite material for "Liquid Resin Infusion", or composite material RTM for "Resin Transfer Molding".

In the three embodiments shown in FIGS. 3 to 6, the arched body 10 comprises:

an arched main wall extending in the plane of curvature and having two arcuate edges of distinct radii of curvature; and

two opposite lateral flanges 16, 17 projecting from the respective arcuate edges of the main wall 15, said lateral flanges 16, 17 extending substantially perpendicularly to said main wall 15.

In the embodiment of Figures 3 and 4, the lateral wings 16, 17 project on the same side of the main wall 15, so that the arcuate body 10 has a radial section in the general shape of "U".

In the embodiment of FIG. 5, the lateral wings 16, 17 project from both sides of the main wall 15, so that the arched body 10 has a radial section in the general shape of "H", in particular of the IPN section type.

In the embodiment of Figure 6, the lateral wings 16, 17 project from both sides of the main wall and are interconnected by a secondary wall 18 substantially parallel to the main wall 15, thus forming a closed box section with two wings.

In a non-illustrated variant, associating the embodiment of FIGS. 3 and 4 and the embodiment of FIG. 6, the lateral wings project on the same side of the main wall and are interconnected by a substantially parallel secondary wall. to the main wall, so that the arched body has a radial section in the general shape of "D".

As can be seen in FIGS. 3 and 4, the arched body 10 may comprise at least one reinforcing rib 19 extending between the lateral wings 16, 17 and integral with the main wall 15. The arched body may, of course, comprise several ribs of reinforcement distributed along the arcuate body 10 between its two ends 1 1, 12.

As shown in Figures 3 to 6, the hinge parts 13, 14 are each constituted by a plate in which is formed a through hole 130, 140 for receiving a ball joint.

Each plate 13, 14 comes in the extension of the main wall 15 and is coplanar with this main wall 15; each plate 13, 14 extending the main wall 15 beyond the lateral wings 16, 17 at each of the ends 1 1, 12.

Advantageously, metal bushings (not shown) are mounted tightly within the through-holes 130, 140 in order to easily replace the ball-and-socket rings if necessary.

The invention thus simplifies the BOM structure of the rear frame 7, lighten the rear frame with respect to frames with metal fittings, and also simplify the industrial scheme and thus reduce production costs.

Of course the implementation example mentioned above is not limiting and other improvements and details can be made to the rear frame according to the invention, without departing from the scope of the invention where others Radial section forms and / or other forms of articulation pieces may for example be made. Thus, any arrangements of geometry of the frame in its current portion as achievable with composite materials may be considered, in order to vary the local inertia of the frame, to arrange passages or openings to place the actuators of maneuvering system. sliding hood.

Again, the thickness of the hinge areas 13 and 14 may be thickened locally to increase the capacity of the ball joints.

The invention is of course not limited to rear frames composed of two half frames, but is applicable to the rear frames composed of a single piece and having a single arched body attached at both ends on a beam or upper beam 12H.

Claims

1. Rear frame (1) for a thrust reversal structure with deflection gates of a turbojet engine nacelle, said rear frame (1) being intended to support a downstream edge of one or more deflection gates and comprising at least one arched body (10) made of composite material and having two free ends (1 1, 12) integral with two respective articulation parts (13, 14) for pivotally fixing said rear frame (1) on at least one supporting structure, characterized in that the hinge parts (13, 14) are made in one piece with the arcuate body (10) of composite material.

2. Rear frame (1) according to claim 1, wherein the arcuate body (10) defines a so-called curvature plane and comprises:

- an arcuate main wall (15) extending in said curvature plane and having two arcuate edges of distinct radii of curvature; and

at least one arcuate side wing (16; 17) projecting from at least one arcuate edge of said central wall, in particular perpendicularly to said main wall (15).

A rear frame (1) according to claim 2, wherein the arcuate body (10) has two opposite arcuate side wings (16,17) protruding from the respective arcuate edges of the main wall (15).

4. Rear frame (1) according to claim 3, wherein the lateral wings (16, 17) project on the same side of the main wall (15), so that the arcuate body (10) has a radial section in general form of "U".

5. Rear frame (1) according to claim 3, wherein the lateral wings (16, 17) project on the same side of the main wall (15) and are interconnected by a secondary wall substantially parallel to the main wall (15), so that the arched body (10) has a radial section in the general shape of "D".

The rear frame (1) according to claim 3, wherein the side wings (16, 17) project from both sides of the main wall (15), so that the arched body (10) has a radial section in the general shape of "H".

7. Rear frame (1) according to claim 3, wherein the side wings (16, 17) project from both sides of the main wall (15) and are interconnected by a secondary wall (18) substantially parallel to the main wall (15).

8. Rear frame (1) according to any one of claims 3 to 7, wherein the arcuate body (10) comprises at least one reinforcing rib (19) extending between the lateral wings (16, 17) and secured of the main wall (15).

9. Rear frame (1) according to any one of the preceding claims, wherein the hinge parts (13, 14) each comprise at least one plate in which is formed at least one through hole (130; 140).

10. Rear frame (1) according to claims 2 and 9, wherein the flats of the hinge parts (13, 14) are in the extension of the main wall (15) and are coplanar with said main wall (15).

1 1. A rear frame (1) according to claims 9 or 10, further comprising metal sockets clamped within the orifices (130, 140) of the hinge pieces (13, 14).

A thrust reversal thrust reversal structure for a turbojet engine nacelle, comprising at least one deflection grid having a downstream edge supported by a rear frame (1) according to any one of the preceding claims.

13. A turbojet engine nacelle comprising a thrust reversal structure according to claim 12 and at least one bearing structure on which are articulated the hinge parts (13, 14) of the rear frame (1) for a pivotal attachment of said frame rear (1).