WO2009101273A1

WO2009101273A1 - Locking system for air intake structure for turbojet engine nacelle

Info

Publication number: WO2009101273A1
Application number: PCT/FR2008/001631
Authority: WO
Inventors: Guy Vauchel; Jean-Philippe Dauguet; Stéphane BEILLIARD
Original assignee: Aircelle
Priority date: 2008-02-01
Filing date: 2008-11-21
Publication date: 2009-08-20
Also published as: EP2252511A1; RU2010135894A; FR2927061A1; FR2927061B1; BRPI0821929A2; CA2711830A1; CN101925515A; RU2500586C2; US20110014044A1

Abstract

The invention relates to a nacelle for a turbojet engine that comprises an air intake structure (2) capable of directing an air flow towards a fan of the turbojet engine, and an intermediate structure for surrounding said fan and to which the air intake structure is attached in order to ensure aerodynamic continuity, wherein the air intake structure includes, on the one hand, at least one inner panel (21) attached to the intermediate structure and defining with the latter a fixed nacelle structure and, on the other hand, at least one longitudinal outer panel (20) removably attached to the fixed structure and including an air intake lip (2a) in order to form a removable air intake structure, characterised in that the air intake structure is provided with peripheral locking means including at least one locking means (10) attached to the inner panel or to the air intake lip and each capable of interacting with an additional retaining means (11) respectively attached to the air intake lip or to the inner panel.

Description

Locking system for air intake structure of a turbojet engine nacelle

The present invention relates to a locking device for a translatable air intake structure equipping a turbojet engine nacelle.

An aircraft is propelled by one or more propulsion units comprising a turbojet engine housed in a tubular nacelle. Each propulsion unit is attached to the aircraft by a mast located generally under a wing or at the fuselage.

A nacelle generally has a structure comprising an air inlet upstream of the engine, a median section intended to surround a fan of the turbojet engine, and a downstream section intended to surround the combustion chamber of the turbojet engine and housing thrust reverser means. .

The air intake comprises, on the one hand, an inlet lip adapted to allow optimal capture to the turbojet of the air necessary to supply the blower and the internal compressors of the turbojet engine, and other on the other hand, a downstream structure to which the lip is attached and intended to properly channel the air towards the blades of the fan, said downstream structure comprising an outer shell and an internal acoustic panel. The assembly is attached upstream of a fan casing belonging to the median section of the nacelle.

The median structure surrounds the blower and generally breaks down into an inner wall forming said blower housing and an outer wall in the form of removable hoods pivotally mounted about a longitudinal hinge axis at the top (at 12 o'clock) of the blower housing. nacelle to allow access to the interior of the nacelle. The assembly of these various elements (movable covers, casing, air intake lip, outer shell, acoustic panel) generates numerous aerodynamic breaks due to the presence of offsets and differences between these elements inherent to their fixation. between them. In addition, the movable covers are mounted on hinges, also generating aerodynamic disturbances. A solution for improving the aerodynamic continuity of the outer surface of a nacelle has been the subject of French patent applications not yet published No. 06/08599 and No. 07/01256.

This solution consists in integrating the air intake lip to the outer shell by including all or part of the cover surrounding the fan casing so as to form a one-piece structure. The entire wall thus formed is movably mounted in translation.

The unpublished French patent application registered under the number 07/03699 describes a manual locking system of said air intake structure and an associated manual system for assisting the translation.

In a turbojet engine nacelle having such a translatable structure, the inner edge of the air intake lip comes, when said translatable structure is in the closed position, in contact with an upstream zone of an internal wall of the structure of the engine. air inlet, inner wall generally made in the form of an acoustic panel.

The translatable structure is guided and held on a fixed structure, including the inner wall of the air inlet structure, by a plurality of rails. The interface is sealed by a seal system and is reinforced by a system of centering pins disposed on the periphery of the air intake lip / acoustic shroud junction and to improve its resistance to radial displacements.

The maintenance of the mobile structure in the longitudinal directions is mainly by buttoning the mobile structure on a fixed structure in an area near an installation interface of the acoustic shroud on the fan casing.

Such a locking system therefore requires a large number of fastening means whose assembly and disassembly are long and tedious.

Furthermore, the interface between the air intake lip and the internal acoustic panel is of particular importance, because this interface must penalize the aerodynamic continuity of the nacelle as little as possible and avoid any distortion of the interface as much as possible. during loading efforts experienced by the air intake or the internal acoustic panel. Also known is a manual locking system comprising a gripping system of the mobile structure by the handle at the end of maneuvering the structure. This technique avoids a long and tedious assembly / disassembly with a system of maintenance by bolting. However, such a system is not suitable for a motorized drive of the mobile structure since the manual drive system and the lock are coupled. It should also be noted that the adjustment of the pre-tension of the locks is also long and tedious. Therefore, there is a need for a locking system of such a mobile structure to solve all or part of these problems.

To do this, the present invention relates to a turbojet engine nacelle comprising an air intake structure adapted to channel a flow of air to a fan of the turbojet engine and a median structure intended to surround said fan and to which is attached the air intake structure to provide aerodynamic continuity, the air inlet structure comprising, on the one hand, at least one inner panel attached to the middle structure and forming therewith a fixed structure of the nacelle, and secondly, at least one longitudinal outer panel removably attached to the fixed structure and incorporating an air inlet lip so as to form a removable air inlet structure, characterized in that that the air inlet structure is equipped with peripheral locking means comprising at least one locking means attached to the inner panel or to the air intake lip and each adapted to cooperate with a complementary retaining means respectively attached to the air intake lip or the inner panel.

Thus, by equipping the junction between the air intake structure and the inner panel of discrete locking means, which can be easily actuated remotely, it is thus possible to easily provide an optimum junction resistance capable of withstanding the deformation forces. .

According to a first embodiment of the invention, the locking means comprises a hook. Advantageously, the hook is a hook with a three-point passing system. According to a second embodiment, the hook is a rotary hook. Preferably, the complementary retaining means is a stirrup. Still preferably, the complementary retaining means is in the form of a return presented by one end of the air intake lip or the inner panel. Advantageously, the inner panel or the air intake lip comprises at least one centering pin capable of cooperating with a corresponding bore of the air inlet lip or the inner panel, respectively.

According to a first variant embodiment, the centering pin is rotatably mounted and has a cam-shaped end adapted to pass alternately between an unlocking position in which the cam-type end can be extracted from the complementary retaining means. and a locking position in which the cam end abuts against the complementary retaining means and can not be extracted therefrom.

According to a second alternative embodiment, the centering pin is rotatably mounted and has an external thread adapted to cooperate with an internal thread of the corresponding bore.

Advantageously, the threaded bore comprises a ball bearing system.

Advantageously, the centering pin has a transverse bore capable of forming a complementary retaining means.

According to another embodiment, the locking means is an electrical locking means capable of being controlled remotely. According to yet another alternative embodiment, the locking means is a manual locking means capable of being controlled remotely by a manual drive means of cable type or mechanical transmission by cardan.

Advantageously, the control means of the locking means are centralized.

Advantageously, the control member is a handle, preferably retractable, adapted to allow the drive of the air inlet structure in displacement.

Preferably, the one or more electric locks are associated with at least one means for detecting the locking and / or unlocking position. Advantageously, the locking means are adjustable in pretension.

The implementation of the invention will be better understood with the aid of the detailed description which is set out below with reference to the appended drawing in which:

Figure 1 is a partial schematic representation of an air intake structure of a nacelle according to the invention, the air inlet structure being in the closed position.

Figure 2 is a partial schematic representation of the air intake structure of Figure 1, the air inlet structure being in the open position.

Figure 3 is an enlarged schematic representation of a three-point lock in the locking position.

Figure 4 is an enlarged schematic representation of the latch of Figure 3 in the open position.

Figure 5 is a schematic representation of a locking mode by rotary hook, said hook being in the open position.

Figure 6 is a representation of the rotary hook of Figure 5 in the locking position. Figure 7 is a representation of a rotary pin locking mode having a cam end, said pin being in the unlocked position.

Figure δ is a representation of the pin of Figure 7 in the locking position. Figures 9 and 10 show a locking mode by threaded rotary pin.

Figures 10 to 14 show two locking modes by picking a centering pin, respectively by a beveled hook and a hook having a corresponding foot to the pin.

A nacelle according to the invention as partially shown in FIGS. 1 and 2 constitutes a tubular housing for a turbojet engine

(not visible) which it serves to channel the air flows it generates by defining internal and external aerodynamic lines necessary to obtain optimal performance. It is also home to different components necessary for the operation of the turbojet as well as ancillary systems such as a thrust reverser.

The nacelle is intended to be attached to a fixed structure of an aircraft, such as a wing, through a pylon. More specifically, the nacelle has a structure comprising a front section forming an air inlet 2, a middle section 3 (partially visible) comprising a housing 3a surrounding a blower (not visible) of the turbojet, and a rear section (not visible) surrounding the turbojet and can house a thrust reversal system (not shown).

The air intake 2 is divided into two zones, namely on the one hand, an inlet lip 2a adapted to allow optimal capture to the turbojet of the air necessary to supply the fan and compressors internal turbojet, and secondly, a downstream structure 2b comprising an outer panel 20 and an inner panel 21, generally acoustic.

According to the nacelle of the prior art to which the present invention applies, the lip 2a is integrated in the outer panel 20 so as to form a single piece removable, the inner panel 21 being attached upstream of the casing 3a of the fan belonging at the median section 3 of the nacelle via fastening flanges 4, secured respectively to the inner panel 21 and the housing 3a.

The air intake structure 2 may be modular and include a plurality of outer panels 20 each defining a corresponding air inlet lip portion 2a.

The inner panel 21 is made from an acoustic shroud and is connected via the flanges 4 to the casing 3a of the middle section 3. This inner panel 21 therefore constitutes a fixed part of the air intake structure 2 on which is intended to be attached and fixed, removably, the outer panel 20 incorporating the air inlet lip 2a.

It will be noted that, alternatively, the outer panel 20 may also comprise all or part of an outer panel of the median structure. To do this, each flange 4 can support a radial peripheral wall 5. This partition 5 may carry centering and secondary centering extending perpendicular to said partition 5 upstream of the nacelle.

It will also be noted that the air intake structure 2 can extend axially through its outer panel 20 beyond a fastening flange of the inner panel 21 to the fixed structure of the platform 1 to neighboring an external structure of a thrust reversal structure belonging to the downstream section of the nacelle and possibly covering the covers. A lock system can then be provided to maintain the air intake structure on the partition 5 integral with the housing structure or an upstream structure of the downstream structure.

It will further be noted that the radial peripheral partition 5 can be carried directly by the same structure of the fan casing in order to provide a maximum of internal envelope to the air inlet 2. The external panel 20 integrating the inlet lip Air 2a thus forms, in accordance with the state of the art, a removable part intended to be attached to the fixed part and more particularly to the peripheral partition 5.

Internal reinforcements of the existing internal and external panels are not shown and depend on the stiffness sought by those skilled in the art.

More particularly, the removable structure may be mounted, for example, on a rail / slide sliding system comprising a plurality of rails / slides distributed on the periphery of the air inlet structure 2 and / or the housing 3a.

According to the invention, the holding of the removable structure is effected at the junction between the air intake lip by discrete locking means comprising at least one hook 10, in this case mounted on the inner panel 21, adapted to cooperate with a complementary retaining means 1 1 caliper type attached to him to the air intake lip 2a.

Figures 1 and 2 show the removable structure respectively in closed and open position.

Figures 3 and 4 are an enlarged view of the locking hook 10 cooperating with the stirrup 1 1. Note that the interface between the air intake lip 2a and the inner panel 21 is completed by centering pins 12, arranged substantially at each hook 10 and carried by a peripheral return 15 of the inner panel 21, each cooperating with a corresponding bore 13 formed in a return 14 of the air inlet lip. The example described uses a hook 10 with a three-point locking system. Such a locking system is known in particular from FR 2,857,400.

The lower form of the hook 10 serves as a release ramp of the stirrup 1 1 during the unlocking maneuver. In particular, the good clearance of the hook 10 relative to the stirrup 1 1 is ensured by means of the shape given to the hook 10 in contact with a fixed axis of rotation of a rod of the three-point system.

Exceeding the three-point system ensures the safety of the lock and ensure the latter in all cases of theft and in case of failure of the drive system of the locking rods.

The hook 10 and the three-point locking system are actuated by an electric motor 30.

The locking and unlocking controls of the electrical locking means are grouped at the level of an external control means of the nacelle and / or at the level of the cockpit of the aircraft.

The retainers 1 1, stirrup type, are positioned on the air intake lip 2a of the nacelle in a zone ensuring the best structural rigidity to avoid any deflection of this interface. Figures 5 and 6 show a second embodiment of the lock comprising a rotary hook 40 driven by an electric motor 41 adapted to engage the return 15 of the inner panel 21 which then serves as complementary retaining means.

The centering pins may also be used directly in the locking means.

Thus, Figures 7 and 8 show a third embodiment in which a centering pin 50 is traversed by a locking cam 52 adapted to be rotated by an electric motor 51 carried by the return 14 of the input structure of air 2a. The pin 50 is able to cooperate with a bore 54 formed in the return 15 of the inner panel 21. The return 21 also carries retaining means 55 of the cam 52 designed so that said cam 52 has a release position in which it can be extracted from the retaining means 55 through the bore 54 and a position of blocking in which it abuts against the retaining means 55 which then prevent its extraction.

Of course, the cam 52 may be an integral part of the pin 50 which is then itself rotated. Advantageously, the pin will however be kept fixed in rotation. Figures 9 and 10 show a screw locking system.

To do this, the return 15 of the inner panel 21 carries a threaded centering pin 60 adapted to be rotated by an electric motor 61. The centering pin 60 is able to cooperate with a threaded bore 62 carried by the return 14 of the air intake lip 2a. The rotation can be improved by the presence of rolling balls 63.

Figures 1 1 to 14 illustrate a locking mode by wedging.

Figures 1 1 and 12 show a wedge locking mode with bevel cam. In this case the inner panel 21 carries a hook 70 adapted to be actuated substantially perpendicularly to the inner panel 21 by an electric motor 71. When the hook 70 is actuated towards the inner panel 21, it is intended to penetrate into a bore 72 formed in a centering pin 73 when it has been inserted through a corresponding bore 74 of the air inlet structure 2a.

The beveled shape of the hook 70 allows adjustment of the pretension of the locking system according to the depth of depression of the hook 70.

Figures 13 and 14 show a locking system by wedging and rectilinear retactation of the pin or the cam.

In this case the inner panel 21 carries a right hook 80 adapted to be actuated substantially perpendicular to the inner panel 21 by an electric motor 81. When the hook 80 is actuated towards the inner panel 21, it is intended to enter the bore 72 formed in the centering pin 73 when it has been inserted through a corresponding bore 74 of the air inlet structure 2a. An impression 82 may be made near one end of the hook 80. Once the hook 80 has been brought into the locking position, the centering pin 73 may be actuated downstream so as to be placed in the fingerprint 82 of the hook 80 and block it. For the unlocking phase, the pin 73 will then be maneuvered first so as to clear the cavity 82 and allow the hook 80 to move away.

In such a case, the pretensioning force is achieved by the pin 73 when the system is reclosed. All the locking systems described in the present application may include means for signaling the locking position and / or unlocking information that can be raised to the cockpit, for example. For greater reliability of this signaling function, the signaling means may be positioned relative to an active locking element ensuring an "all or nothing" signal. The signaling means are preferably placed on the inner panel 21 constituting a fixed part of the nacelle in order to reduce the disconnection interfaces, which is one of the factors for reducing the reliability of the system. The locking systems described can also be adjustable pre-tension.

In the case of the hook 10 shown in FIGS. 1 to 4, the pretensioning adjustment may be effected by fixing the locking means on an adjustable plate (for example by a screw) allowing a slight translation along the inner panel 21. Adjusting the caliper 1 1 can be done in the same way.

Concerning the rotary hook lock 40 shown in FIGS. 5 and 6, the pretensioning adjustment may be effected by adjusting the position of the lock by setting the motor housing 41 or else by acting on an axis of the hook 40.

Advantageously, the electrical and / or manual control means of the locking means may be centralized, said control being able to be, for example, located internally of the median structure and accessible after opening of an outer panel of this structure, is apparent to the structure and directly accessible from outside the nacelle. In the case of direct accessibility, the control may, for example, be in the form of an unprotected appendage aerodynamically, be protected by a hatch or a maneuvering box for external aerodynamic smoothing. It will be noted that the examples presented show an electric motor latch, but it is obviously possible to provide a reduced number of electric motors, or even a single electric motor, so the driving force is returned to the various locks by a mechanical drive system . Advantageously also, there will be provided a centralized system for mechanical unlocking of the electric locks in case of failure of one or more electric motors. Indeed, normally, each lock should be accessed individually by a dedicated access door. These traps would then generate significant aerodynamic disturbances in addition to being heavy, expensive and disrupt the structural integrity of the external structure.

Each electric motor can then advantageously be equipped with a manual control module (MDU) capable of being actuated by a mechanical drive system with centralized manual control.

Finally, it is also possible to provide a mechanical inhibition system of the locking means, preferably visible from the outside. Such mechanical inhibition may be in the form of a locking pin having an appendix introduced into the manual control member and adapted to block the latter.

Although the invention has been described with a particular embodiment, it is obvious that it is in no way limited and that it includes all the technical equivalents of the means described and their combinations if they enter into the scope of the invention. Note also that most of the lock modes presented can be used for other nacelle interfaces, including the upstream interface between the removable air intake structure and the fan casing.

Claims

1. Nacelle for turbojet comprising an air inlet structure (2) adapted to channel an air flow to a fan of the turbojet engine and a median structure (3) intended to surround said fan and to which is attached the input structure of air to provide aerodynamic continuity, the air intake structure comprising, on the one hand, at least one inner panel (21) attached to the medial structure and forming with the latter a fixed structure of the nacelle and, on the other hand, at least one longitudinal outer panel (20) removably attached to the fixed structure and incorporating an air inlet lip (2a) so as to form a removable air inlet structure characterized in that the air inlet structure is provided with peripheral locking means comprising at least one locking means (10, 40, 50, 60, 70, 80) attached to the inner panel or the lip 'air inlet and fit each to cooperated with complementary retaining means (11, 15, 55, 62, 73) respectively attached to the air inlet lip or the inner panel.

2. Nacelle according to claim 1, characterized in that the locking means comprises a hook (10).

3. Nacelle according to claim 2, characterized in that the hook (10) is a hook with three-point system.

4. Nacelle according to claim 3, characterized in that the hook is a rotary hook (40).

5. Nacelle according to. any one of claims 2 to 4, characterized in that the complementary retaining means is a stirrup (1 1).

6. Platform according to any one of claims 2 to 4, characterized in that the complementary retaining means is presented in the form of a return (14, 15) provided by one end of the air inlet lip (2a, 21) or the inner panel.

7. Platform according to any one of claims 1 to 6, characterized in that the inner panel (21) or the air inlet lip

(2a) comprises at least one centering pin (12, 50, 60, 73) adapted to cooperate with a corresponding bore (13) of the air intake lip or the inner panel, respectively;

8. Nacelle according to claim 7, characterized in that the centering pin (50) is rotatably mounted and has a cam-shaped end (52) adapted to pass alternately between an unlocking position in which the end of cam type may be extracted from the complementary retaining means (55) and a locking position in which the cam end abuts against the complementary retaining means and can not be extracted from it.

9. Nacelle according to claim 7, characterized in that the centering pin (60) is rotatably mounted and has an external thread adapted to cooperate with an internal thread of the bore (62) corresponding.

10. Platform according to claim 9, characterized in that the threaded bore (62) comprises a ball bearing system (63).

1 1. Nacelle according to claim 7, characterized in that the centering pin (73) has a transverse bore (72) adapted to form a complementary retaining means.

12. Nacelle according to any one of claims 1 to 11, characterized in that the locking means is an electrical locking means adapted to be remotely controlled.

13. Platform according to any one of claims 1 to 11, characterized in that the locking means is a means of manual locking adapted to be controlled remotely by manual drive means of cable type or mechanical gimbal.

14. Nacelle according to any one of claims 12 or 13, characterized in that the means of icomrηande locking means are centralized.

15. Nacelle according to claim 12 to 14, characterized in that the control member is a handle, preferably retractable, adapted to allow the driving of the air inlet structure (2a) in displacement.

16. Nacelle according to any one of claims 1 to 15, characterized in that the one or more electric locks are associated with at least one means for detecting the locking position and / or unlocking.

17. Nacelle according to any one of claims 1 to 16, characterized in that the locking means are adjustable in pretension.