Overpressure door for a rear hood of an aircraft engine mast

Description

Technical field

[0001] The invention belongs to the field of aeronautical structures. More particularly, the invention belongs to the field of masts for supporting engines on the wings of an aircraft and their cowling. Prior art

[0002] Masts are aerostructure elements intended to support the engines of an aircraft, generally but not exclusively under the wings of the aircraft, as well as to transmit the thrust of said engines to the aircraft.

[0003] These masts receive an aerodynamic cowling made of thin metal panels or composite materials, assembled on an underlying structure of stiffeners.

[0004] Equipment and in particular fluid transport pipes, in particular air pipes, use the internal space protected by said covers.

[0005] In accidental circumstances, the rupture of such piping is likely to cause dangerous overpressure inside the cowling, with the risk of degradation of said cowling and exposure of the elements it contains to external conditions.

[0006] In order to limit this risk, an engine mast cowling includes at least one pressure relief door which opens automatically at a determined pressure, thus putting the interior of the cowling under external pressure and preventing its deterioration.

[0007] These pressure relief doors are frequently integrated into a side panel of the mast cowling.

[0008] Document EP2660148 describes a pressure relief door device adaptable to a panel, documents FR2920134 and EP2356028 describe suppression doors installed on nacelles, but whose operating principles are similar to those of pressure relief doors installed on an engine mast cowling.

[0009] These suppression doors are however frequently confused, or improperly used, as access hatches to equipment located under the hoods, they are then "forced" by maintenance operators at the risk of degrading their operation, either by compromising their function or by untimely openings.

[0010] For example, document FR3120854 / US2022 / 0297845 describes a reactor mast comprising a movable cover allowing access to the interior of the mast. This cover comprises a system of slides allowing it to be moved between a locked position and an unlocked position, so as to easily open this cover. Thus this cover is an inspection hatch, intended to be easily opened and closed to access the interior of the mast.

[0011] The purpose of the end cover described below is to provide protection against overpressure so that if this cover is opened, either by overpressure or by "forcing", it cannot be easily closed. Summary of the invention

[0012] The invention aims to solve the drawbacks of the prior art and to this end relates to a rear end cowling of an engine pylon, the engine pylon being configured to fix an engine to a wing of an aircraft, said end cowling comprising a first part fixed to one between the wing and the engine pylon, and a second part at the rear end, linked to the first part by a hinge and a traction device capable of maintaining the second part in a closed configuration in sealed continuity with the first part and one between the wing and the engine pylon to which the first part is fixed, in which the hinge and the traction device are produced by independent means and separated from each other.

[0013] Thus, unlike the prior art, the use of independent means for producing the hinge and the traction device makes it possible, depending on the embodiments, to prevent any easy closing of the hood when it is open.

[0014] The invention can be implemented according to the embodiments and variants set out below which are to be considered individually or according to any technically operative combination.

[0015] Advantageously, the traction device comprises a locking means for maintaining the second part in the closed configuration.

[0016] Advantageously, the traction device comprises a connecting rod connected at one end to the second part and at another end to the first part, the locking means comprising an unlocking device under the action of a traction force exerted on the connecting rod, following a level of pressure internal to the rear end cowling and acting on the second part, bringing the second part into an open configuration.

[0017] According to one embodiment the locking means comprises a second locking configuration when the second part is in the open configuration. Brief description of the drawings

[0018] The invention is implemented according to the preferred embodiments, in no way limiting, described below with reference to [Fig.1] to [Fig.3] in which: Fig. 1 [ Fig. 1 ] is a perspective view of a wing section of an aircraft including an engine pylon; Fig.2 [ Fig.2 ] shows in a perspective view an example of an embodiment of a rear end cowling with a pressure relief door in the open configuration; Fig. 3 [ Fig. 3 ] shows according to a perspective view in AA section defined [ Fig.2 ] an example of the embodiment of a locking device. Description of the embodiments

[0019] [ Fig. 1 ] the pressure relief door (100) which is the subject of the invention is located at the rear end of a so-called “cover” gutter » which extends between the rear end of the rear engine mast structure (40), commonly referred to as RSS, the latter being connected, at the front, to an engine mast (30) ensuring the connection of an engine (20) to a wing (10) of an aircraft.

[0020] This end cowling aerodynamically completes the connection of the rear structure of the mast with the lower surface of the wing in this example of realization.

[0021] A person skilled in the art will understand that a similar configuration is possible without departing from the scope of the invention when the engine mast is connected to the upper part of the wing and the rear end cowling provides an aerodynamic connection with the upper surface of the wing.

[0022] This end cowling is a hollow part made of a metallic or composite material, watertightly attached to either the wing or the engine pylon by suitable fasteners.

[0023] [ Fig.2 ] the device which is the subject of the invention (100) is located at the end of this rear end cowling, as an extension of the external aerodynamic shape. This area is lightly loaded from an aerodynamic point of view in flight, which makes it possible to lighten the devices, more particularly the connecting and locking device.

[0024] According to this exemplary embodiment, it comprises a first part (210), here fixed to the wing and to the RSS, and a second part (220) linked to the first part by a hinge (230) and a locking mechanism.

[0025] According to another embodiment (not shown) the first part is fixed to the engine mast.

[0026] The locking mechanism, shown here in the unlocked configuration, comprises, according to this exemplary embodiment, a lock (241), fixed on a platform (250) linked to the first part (210), a connecting rod (242) and means (243) for attaching the connecting rod to the second part (220).

[0027] The two parts comprise a peripheral seal (261, 262) ensuring sealing with the wing, or with the engine mast depending on the embodiment.

[0028] The pressure relief door is made up of the second part (220), it is shown here open. To close it, it must be brought closer to the first part (210) by pivoting it around the hinge (230) until it locks. The two parts (210, 220) are then joined, in extension of one another, in complete connection with one another, an internal and external flexible sealing strip (270) ensuring the sealing of the connection.

[0029] Thus locked the end cowling can be assembled to the wing and the RSS.

[0030] The unlocking mechanism is calibrated to trigger at a determined overpressure. In the event of such an event, said mechanism is triggered and pushes the second part (220) which opens, exposing all of the volumes delimited by the mast covers to the air.

[0031] [ Fig. 3] according to an exemplary embodiment the lock comprises a cam (310) articulated around a pivot connection (351) in a yoke (350) which is fixed to the platform.

[0032] The connecting rod (not shown) is connected to the top of the cam by a pivot link. In the configuration of [ Fig. 3 ] the pressure relief door is closed, that is to say that [ Fig.2 ] the second part (220) and joined with the first part and the seal (262) is applied in contact with the wing.

[0033] In the case of overpressure, the pressure applied to the second part (220) pushes it to bring it into the configuration of [ Fig.2 ]. The traction thus applied to the connecting rod (242) pulls on the upper part of the cam (310) according to a force (342).

[0034] Coming back to [ Fig. 3] the force (342) applied by the connecting rod tends to rotate the cam (310) around its pivot axis. Said cam (310) is however blocked by a needle (360) which cooperates with a stop (312) forming a ratchet made on the cam surface.

[0035] The needle (360) is held in contact with the stop (312) by means of a rocker (361). Said rocker is in pivot connection with the yoke (350) and is held in the position of [ Fig. 3 ] by a compression spring (370) calibrated to a given force. In a way, the rocker, needle and spring assembly form a pawl which cooperates with the stop (312) forming a ratchet.

[0036] When the force (342) acting on the cam becomes too high, that is to say in the presence of overpressure, the stop (312) retracts the needle (360) which pivots with the rocker (361), the force exerted by the spring (370) no longer being sufficient to hold the rocker in position.

[0037] The cam pivots about its pivot axis (351) thus allowing the connecting rod to move in the direction of the force (342) and the pressure relief door to open.

[0038] The cam (310) continues its rotation until the needle (360) comes, under the action of the spring (370), to lodge in a notch (313) arranged on the surface of the cam. The cam and the connecting rod are then locked in this position, called unlocked, and the overpressure door remains open.

[0039] The unlocked position is stable so that the second part (220) can no longer naturally return to alignment with the first part and the only way to close the overpressure door is to dismantle the entire rear end cowling.

[0040] Unlike the prior art, the functions of articulation and calibrated traction of the second part (220) relative to the first part (210) are performed by separate devices acting independently of each other, in this case the hinge (230) for the articulation and the connecting rod (242) associated with the locking means for the application of one part against the other, where, for example, FR3120854, uses the same connecting rod to perform these two functions.

[0041] The separation of these functions allows both rapid and efficient opening in the event of overpressure while preventing the hood from being closed without disassembly when it is open, whatever the cause.

[0042] Thus, on the one hand, the position of the overpressure door, at the rear end of the rear end cowling, does not encourage an operator to force the opening of this door to access equipment.

[0043] Furthermore, if an unscrupulous operator nevertheless forces the overpressure door open, it is impossible to close it again, except by removing the entire rear end cowling, which requires reporting to a supervisor.

Claims

1. Rear fairing (100) of an engine pylon, the engine pylon (30) being configured to attach an engine (20) to a wing (10) of an aircraft, said rear end cowling comprising a first part (210) attached to one of the wing and the engine pylon, and a second part (220) at the rear end, connected to the first part (210) by a hinge (230) and a traction device (241, 242, 243) capable of holding the second part (220) in a closed configuration in sealed continuity with the first part (210) and one of the wing and the engine pylon to which the first part is attached, characterized in that the hinge (230) and the traction device (241, 242, 243) are made by independent means and separated from each other.

2. The fairing of claim 1, wherein the traction device comprises a locking means (241) to keep the second part (220) in the closed configuration.

3. The fairing of claim 2, wherein the traction device comprises a rod (242) connected at one end to the second part (220) and at another end to the first part (210), the locking means (241) comprising an unlocking device under the action of a pulling force (342) exerted on the rod (242), following an internal pressure level at the rear end of the cowling and acting on the second part (220), bringing the second part into an open configuration.

4. The fairing of claim 3, wherein the locking means (241) comprises a second locking configuration when the second part (220) is in the open configuration.