Overpressure door for a rear end cowling of an aircraft engine support mast

Abstract

The invention relates to a rear end cowling (100) of an engine mast, the engine mast (30) being configured to fix an engine (20) to a wing (10) of an aircraft, said end cowling comprising a first part (210) fixed to one between the wing and the engine mast, and a second (220) rear end part, linked to the first part (210) by a hinge (230) and a traction device (241,242,243) capable of maintaining the second part (220) in a closed configuration in continuous, airtight connection with the first part (210) and one between the wing and the engine mast to which the first part is fixed.

Description

Title of the invention: Overpressure door for a rear end cowling of an aircraft engine support mast technical field

[0001] The invention relates to the field of aeronautical structures. More particularly, the invention relates to the field of engine masts for supporting aircraft wings and their cowling. Previous technique

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

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

[0004] Equipment and in particular fluid transport piping, in particular air piping, uses the internal space protected by said enclosures.

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

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

[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. Summary of the invention

[0010] The invention aims to overcome the drawbacks of the prior art and relates to this purpose a rear end cowling for an engine pylon, the engine pylon being configured to attach an engine to an aircraft wing, said end cowling comprising a first part fixed to a point between the wing and the engine pylon, and a second rear end part connected to the first part by a hinge and a tensioning device capable of maintaining the second part in a closed configuration in a sealed, continuous connection with the first part and a point between the wing and the engine pylon to which the first part is attached

[0011] 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 feasible combination.

[0012] Advantageously, the traction device includes a locking means to maintain the second part in the closed configuration.

[0013] Advantageously, the traction device comprises a connecting rod linked at one end to the second part and at the other end to the first part, the locking means comprising a unlocking device under the action of a traction force exerted on the connecting rod, resulting from a level of internal pressure in the rear end cover and acting on the second part, bringing the second part into an open configuration.

[0014] According to one embodiment, the locking means includes a second locking configuration when the second part is in the open configuration. Brief description of the drawings

[0015] The invention is implemented according to the preferred, non-limiting embodiments described below with reference to [Fig. 1] to [Fig. 3] in which: Fig. 1

[0016] [Fig.1] is a perspective view of a wing section of an aircraft including a motor mast; Fig. 2

[0017] [Fig.2] shows, in perspective view, an example of the implementation of a hood rear end with a pressure relief door in open configuration; Fig.3

[0018] [Fig.3] shows, according to a perspective view in section AA defined [Fig.2], an example for the creation of a locking device. Description of the implementation methods

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

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

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

[0022] This end cowling is a hollow part made of a metallic or composite material, connected in a hermetic fashion to either the wing or the engine mast by suitable fasteners.

[0023] [Fig.2] The device that is the subject of the invention (100) is located at the end of this casing at the rear end, extending from the external aerodynamic shape. This area is less aerodynamically loaded in flight, which allows for lighter components, particularly the linkage and locking mechanism.

[0024] According to this embodiment, it comprises a first part (210), here fixed to the wing and 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 motor mast.

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

[0027] The two parts include a peripheral seal (261, 262) ensuring sealing with the wing, or with the motor mast according to the embodiment.

[0028] The pressure relief valve is formed by the second part (220), shown here in the open position. 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, extending from one another, and fully connected, with an internal and external flexible sealing strip (270) ensuring the seal 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 predetermined overpressure. In the event of such an occurrence, said mechanism is triggered and pushes the second part (220) which opens, exposing to the air all the volumes delimited by the mast covers.

[0031] [Fig.3] According to one embodiment, the lock comprises an articulated cam (310) around a pivot joint (351) in a clevis (350) which is fixed to the platform.

[0032] The connecting rod (not shown) is linked to the top of the cam by a pivot joint. In the configuration of [Fig.3] the overpressure gate is closed, i.e. [Fig.2] the second part (220) is 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 into the configuration of [Fig.2]. The resulting tension applied to the connecting rod (242) pulls on the upper part of the cam (310) with a force (342).

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

[0035] The needle (360) is held in contact with the stop (312) by means of a rocker arm (361). This rocker arm is pivotally connected to the yoke (350) and is held in the position shown in [Fig. 3] by a compression spring (370) set to a given force. In a sense, the rocker arm, needle, and spring assembly form a ratchet that engages with the stop (312), acting as a ratchet mechanism.

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

[0037] The cam pivots around its pivot axis (351) thus allowing the connecting rod to move in the direction of the force (342) and the overpressure gate to open.

[0038] The cam (310) continues its rotation until the needle (360), under the action of the spring (370), comes to rest in a notch (313) formed on the surface of the cam. The cam and the connecting rod are then locked in this position, known as the unlocked position, and the overpressure gate 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 cover.

[0040] Thus, on the one hand, the position of the overpressure door, at the rear end of the rear end cover, does not encourage an operator to force the opening of this door to access equipment.

[0041] Moreover, if an unscrupulous operator forces the overpressure door open despite everything, it is impossible for him to close it again, except by dismantling the entire rear end cover, which requires reporting to a supervisor.

Claims

Demands

1. Rear end cowling (100) of an engine mast, the engine mast (30) being configured to fix an engine (20) to a wing (10) of an aircraft, said rear end cowling comprising a first part (210) fixed to one between the wing and the engine mast, and a second (220) rear end part, connected to the first part (210) by a hinge (230) and a traction device (241, 242, 243) capable of maintaining the second part (220) in a closed configuration in continuous, watertight connection with the first part (210) and one between the wing and the engine mast to which the first part is fixed.

2. A hood according to claim 1, wherein the traction device includes a locking means (241) for maintaining the second part (220) in the closed configuration.

3. Hood according to claim 2, wherein the traction device comprises a connecting rod (242) linked at one end to the second part (220) and at the other end to the first part (210), the locking means (241) comprising a unlocking device under the action of a traction force (342) exerted on the connecting rod (242), resulting from a level of pressure internal to the rear end hood and acting on the second part (220), bringing the second part into an open configuration.

4. A hood according to claim 3, wherein the locking means (241) includes a second locking configuration when the second part (220) is in the open configuration.

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