AIRCRAFT WITH AT LEAST ONE OVERPRESSURE DEVICE

Description

[0001] The present application relates to an aircraft equipped with at least one overpressure device comprising a movable wall maintained in the closed position as long as its deformation does not exceed a given deformed state.

[0002] According to an embodiment visible on the figure 1 , an aircraft comprises several aircraft masts 10 each connecting a propulsion assembly 12 and a wing 14.

[0003] Each mast 10 comprises a primary structure ensuring the transmission of forces between the propulsion assembly 12 and the wing 14 which it connects as well as a secondary structure 16 which envelops the primary structure and forms an aerodynamic surface. This secondary structure 16 comprises a hot air exhaust 18 provided with a static grille as well as a pressure relief device 20.

[0004] When the pressure in an interior zone located below the secondary structure 16 is lower than a given value, the pressure relief device 20 is in a closed position. As soon as, accidentally, the pressure in the interior zone exceeds this given value, the pressure relief device 20 opens and occupies an open position.

[0005] According to an embodiment visible on the figures 2 à 4 , the pressure relief device 20 comprises a door 22 which has front and rear edges 22.1, 22.2 substantially perpendicular to a vertical median plane PMV as well as lateral edges 22.3, 22.4 substantially symmetrical with respect to the vertical median plane PMV.

[0006] The pressure relief device 20 comprises a hinge 24 for connecting the door 22 to the secondary structure 16, comprising swan necks for example, positioned at the front edge 22.1 and allowing the door 22 to switch between the closed and open positions. To maintain the door 22 in the closed position, the pressure relief device 20 comprises two locking systems 26 located at the rear edge 22.2 and positioned symmetrically with respect to the vertical median plane PMV.Each locking system 26 comprises a latch movable between a locked state in which it holds the door 22 in the closed position and an unlocked state in which it allows the door 22 to swing into the open position, as well as a spring for holding the latch in the locked state against forces, in particular those generated by the pressure in the interior zone, as well as those generated by the external pressure due to the aeronautical depression. Each locking system 26 comprises an adjustment system for adjusting the pressure from which the latch swings from the locked state to the unlocked state and allows the door 22 to pivot into the open position.

[0007] In practice, the tilting of door 22 into the open position occurs only very rarely.

[0008] This embodiment is not fully satisfactory because the articulation 24 and the locking systems 26 are relatively bulky, expensive and have a significant mass in relation to the frequency of the tilting of the door 22 into the open position. The present invention aims to remedy all or part of the drawbacks of the prior art.

[0009] Document WO2010066958 discloses a pressure relief hatch intended to be mounted on a wall of a turbojet engine nacelle.

[0010] To this end, the invention relates to an aircraft comprising at least one overpressure device comprising at least one fixed part and at least one movable wall configured to occupy a closed position in which the movable wall closes an opening and isolates interior and exterior zones positioned on either side of the movable wall and an open position in which the movable wall at least partially clears the opening, the movable wall having an interior face oriented towards the interior zone and an exterior face oriented towards the exterior zone, the overpressure device comprising at least one articulation connecting the movable wall and the fixed part as well as at least one holding system configured to hold the movable wall in the closed position as long as a pressure in the interior zone is lower than a given pressure value, the movable wall comprising at least one edge.

[0011] According to the invention, the movable wall is configured to deform so that the movable wall occupies a given deformed state when the pressure in the interior zone is at the given pressure value. In addition, the holding system comprises at least a first slot passing through the movable wall and opening at the edge of the movable wall as well as, for each slot, a first holding element secured to the fixed part, the first holding element and the first slot being configured so that: the first holding element is housed in the first slot and holds the movable wall in the closed position as long as the movable wall is not in the given deformed state, the first holding element is no longer housed in the first slot and no longer holds the movable wall in the closed position as soon as the movable wall is in the given deformed state.

[0012] In addition, each holding element is in the form of a screw which comprises a body screwed into the fixed part as well as a countersunk head, each slot having an edge which flares from the inner face towards the outer face of the movable wall, the head having a section greater than the smallest section of the slot in which the holding element is housed.

[0013] Such a holding system has a smaller footprint, lower costs and lower mass than prior art locking systems.

[0014] According to another characteristic, the movable wall comprises first and second transverse edges as well as first and second lateral edges, the articulation being positioned at the first transverse edge. In addition, the movable wall is configured to deform in a direction of deformation substantially perpendicular to the first and second transverse edges so that the first and second transverse edges move closer together when the movable wall deforms, the holding system comprising at least one slot which opens onto one of the first and second lateral edges.

[0015] According to another characteristic, the holding system comprises first and second slots opening onto each of the first and second lateral edges.

[0016] According to another characteristic, the movable wall is substantially symmetrical with respect to a vertical median plane substantially perpendicular to the first and second transverse edges. In addition, the first and second slots are substantially symmetrical with respect to the vertical median plane.

[0017] According to another characteristic, the movable wall comprises a length corresponding to a distance separating the first and second transverse edges. In addition, the first and second slots are separated from the second transverse edge by a distance less than 1 / 3 of the length of the movable wall.

[0018] According to another characteristic, each of the first and second slots extends between a first end, opening at the first or second lateral edge, as well as a second end opposite the first end and has a median axis, connecting the first and second ends, forming an angle less than or equal to 20° with a vertical plane and perpendicular to the vertical median plane.

[0019] According to another characteristic, the articulation comprises at least two deformable connecting tabs comprising a first part secured to the movable wall, a second part secured to the fixed part as well as an intermediate omega part connecting the first and second parts.

[0020] According to another feature, each connecting tab is made of a material that deforms plastically when the movable wall moves from the closed position to the open position.

[0021] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which: There figure 1 is a perspective view of a secondary structure of an aircraft mast illustrating one embodiment, The figure 2 is a perspective view of a pressure relief door in the closed position illustrating a prior art embodiment, The figure 3 is a longitudinal section of the pressure relief door visible on the figure 2 in open position, The figure 4 is a bottom view of the pressure relief door visible on the figure 2 in closed position, The figure 5 is a perspective view, from an exterior area of ​​a secondary structure of an aircraft mast, of a pressure relief device in the closed position illustrating an embodiment of the invention, The figure 6 is a longitudinal section of a pressure relief device illustrating an embodiment of the invention, The figure 7 is a cross-section of a pressure relief device illustrating one embodiment of the invention, The figure 8 is a bottom view of a pressure relief device illustrating an embodiment of the invention, The figure 9 is a perspective view of a portion of a joint of a pressure relief device illustrating an embodiment of the invention, The figure 10 is a cross-section of a system for maintaining a pressure relief device in the closed position illustrating an embodiment of the invention, The figure 11 is a perspective view of the closed position holding system visible on the figure 10 .

[0022] According to an embodiment visible on the figures 5 à 8 , a fairing 30 separates an interior zone ZI positioned below the fairing 30 and an exterior zone ZE positioned above the fairing 30. According to one application, the fairing 30 corresponds to a secondary structure of an aircraft mast.

[0023] The fairing 30 comprises an opening 32 allowing the inner and outer zones ZI and ZE to communicate as well as a pressure relief device 34 comprising at least one movable wall 36 configured to occupy a closed position in which the movable wall 36 closes the opening 32 and isolates the inner and outer zones ZI, ZE as well as an open position in which the movable wall 36 at least partially clears the opening 32, the inner and outer zones ZI, ZE communicating with each other. Around the opening 32, the fairing 30 comprises an outer face F30 in contact with an aerodynamic flow. The movable wall 36 has an inner face F36 oriented towards the inner zone ZI and an outer face F36' oriented towards the outer zone ZE flush with the outer face F30 of the fairing 30.

[0024] According to one embodiment, the movable wall 36 is symmetrical with respect to a vertical median plane PMV. It comprises a first transverse edge 36.1 positioned in a first plane substantially perpendicular to the vertical median plane PMV, a second transverse edge 36.2 positioned in a second plane substantially parallel to the first plane and perpendicular to the vertical median plane PMV as well as first and second lateral edges 36.3, 36.4 connecting the first and second transverse edges 36.1, 36.2 and symmetrical with respect to the vertical median plane PMV.

[0025] According to this embodiment, the opening 32 comprises first and second transverse sides 32.1, 32.2 positioned in planes substantially perpendicular to the vertical median plane PMV as well as first and second lateral sides 32.3, 32.4 connecting the first and second transverse sides 32.1, 32.2.

[0026] The movable wall 36 and the opening 32 are configured so that there remains zero or low clearance between respectively the first and second transverse edges 36.1, 36.2 of the movable wall 36 and the first and second transverse sides 32.1, 32.2 of the opening 32 as well as between respectively the first and second lateral edges 36.3, 36.4 of the movable wall 36 and the first and second lateral sides 32.3, 32.4 of the opening 32 in the absence of deformation of the movable wall 36.

[0027] By small clearance, it is meant that each edge 36.1 to 36.4 of the movable wall 36 is separated from the side 32.1, 32.4 of the corresponding opening 32 by a distance less than or equal to 5 mm.

[0028] According to one application, the overpressure device 34 is positioned at the secondary structure of an aircraft mast so that the vertical median plane PMV of the movable wall 36 coincides with the vertical median plane PMV of the aircraft mast. The first transverse edge 36.1 is oriented towards the front of the aircraft and the second transverse edge 36.2 is oriented towards the rear of the aircraft. Of course, the invention is not limited to this application. Thus, an aircraft may comprise one or more overpressure device(s). According to one embodiment, as illustrated in the figure 7 , the movable wall 36 has a radius of curvature in a transverse plane (vertical and perpendicular to the vertical median plane PMV). According to this embodiment, the movable wall 36 comprises, at the level of the vertical median plane PMV, an upper generatrix 36.5 connecting the first and second transverse edges 36.1, 36.2, offset upwards relative to the first and second lateral edges 36.3, 36.4.

[0029] According to one configuration, the movable wall 36 has an approximately cylindrical shape.

[0030] The movable wall 36 is configured to be able to deform, in particular when the pressure in the interior zone ZI increases, so that the first and second lateral edges 36.3, 36.4 move closer together.

[0031] The overpressure device 34 comprises at least one fixed part 40 as well as at least one articulation 38 connecting the movable wall 36 and the fixed part 40. According to one configuration, the fixed part 40 comprises, at the first side 32.1 of the opening 32, a wall which comprises an inner face F40 oriented towards the inner zone Z1 and an outer face F40' oriented towards the outer zone ZE. According to one arrangement, in the case of an overpressure device 34 positioned on the secondary structure of an aircraft mast, the fixed part 40 is a wall positioned at the front of the movable wall 36, the articulation 38 connecting the first transverse edge 36.1 of the movable wall 36 and the fixed wall 40.

[0032] According to an embodiment not shown, the articulation 38 comprises swan necks.

[0033] According to another embodiment visible in particular on the figures 8 et 9 , the articulation 38 comprises at least two deformable connecting tabs 42 positioned on either side of the vertical median plane PMV, each connecting tab 42 comprises a first part 42.1 secured to the movable wall 36, a second part 42.2 secured to the fixed part 40 as well as an intermediate part 42.3 in omega connecting the first and second parts 42.1, 42.2. The first part 42.1 is pressed against the inner face F36 of the movable wall 36 and connected to the latter by gluing, by welding or by means of through-fixing elements such as rivets or bolts for example.

[0034] The second part 42.2 is pressed against the inner face F40 of the fixed wall 40 and connected to the latter by gluing, by welding or by means of through-fixing elements such as rivets or bolts for example.

[0035] At least one zone of the intermediate part 42.3 is spaced from the movable and fixed walls 36, 40 and offset towards the interior zone ZI relative to the latter.

[0036] Each connecting tab 42 is in the form of a thin strip of material such as sheet metal for example.

[0037] According to one embodiment, each connecting tab 42 is made of a material that deforms plastically when the movable wall 36 moves from the closed position to the open position. According to one configuration, each connecting tab 42 is made of stainless steel of grade Z6 for example. Thanks to the ability of the connecting tabs 42 to deform plastically and not elastically, the movable wall 36 tends to remain in the open position and not to close due to possible elastic properties of the connecting tabs 42. According to an arrangement visible on the figure 8 , the articulation 38 comprises four connecting tabs 42 arranged symmetrically with respect to the vertical median plane PMV.

[0038] Providing connecting legs 42 instead of swan necks reduces the size, cost and mass of the joint 38.

[0039] According to a configuration visible on the figure 6 , the fixed part 40 comprises a transverse rim 44 positioned opposite the articulation 38, at the level of the second transverse edge 36.2 of the movable wall 36, having a contact face F44 against which the movable wall 36 is in contact when it is in the closed position. The contact face F44 is offset towards the inner zone ZI relative to the outer face F30 of the fairing 30 so that the outer face F36' of the movable wall 36 and the outer face F30 of the fairing are flush when the movable wall 36 is in the closed position.

[0040] According to one embodiment, the overpressure device 34 comprises at least one link for keeping the movable wall 36 half-open, positioned at the level of the second edge 36.2, opposite the articulation 38, connecting the movable wall 36 and the fairing 30.

[0041] According to one configuration, the movable wall 36 comprises at least one orifice 46 passing through it. According to one configuration, the movable wall 36 comprises several oblong orifices 46 (each of them being symmetrical with respect to the vertical median plane PMV).

[0042] The pressure relief device 34 also comprises at least one holding system 48 configured to hold the movable wall 36 in the closed position as long as a pressure in the inner zone ZI is lower than a given pressure value. When the pressure in the inner zone ZI reaches the given pressure value, the movable wall occupies a given deformed state.

[0043] According to one embodiment, the holding system 48 comprises a first slot 50.1 passing through the movable wall 36 and opening at its first lateral edge 36.3, a second slot 50.2 passing through the movable wall 36 and opening at its second lateral edge 36.4, a first holding element 52.1 secured to the fixed part 40, positioned at the first lateral side 32.3 of the opening 32 and configured to cooperate with the first slot 50.1 when the movable wall 36 is in the closed position and in an undeformed state, as well as a second holding element 52.2 secured to the fixed part 40, positioned at the second lateral side 32.4 of the opening 32 and configured to cooperate with the second slot 50.2 when the movable wall 36 is in the closed position and in an undeformed state.

[0044] According to one configuration, the fixed part 40 comprises a first lateral rim 54, in line with the first slot 50.1, against which the inner face F36 of the movable wall 36 bears in the closed position and in the undeformed state, as well as a second lateral rim, in line with the second slot 50.2, against which the inner face F36 of the movable wall 36 bears in the closed position and in the undeformed state.

[0045] As illustrated on the figures 10 et 11 , each of the first and second holding elements 52.1, 52.2 is in the form of a screw 56 which comprises a body 56.1 screwed into the fixed part, more particularly into the first or second lateral rim 54, as well as a head 56.2 having a section greater than the smallest section of the first or second slot 50.1, 50.2.

[0046] According to one configuration, the head 56.2 is a countersunk head. In addition, each of the first and second slots 50.1, 50.2 has an edge 58 which flares from the inner face F36 towards the outer face F36'. According to one configuration, the opposite portions of the edge 58 delimiting the first or second slot 50.1, 50.2 form an angle substantially identical to the angle formed by the countersunk head. Thus, each of the first and second slots 50.1, 50.2 has a smaller section at the level of the inner face F36 of the movable wall 36 which is greater than the section of the body 56.1 of the screw 56 and less than the largest section of the head 56.2 of the screw 56 as well as a larger section at the level of the outer face F36' of the movable wall 36 which is substantially equal to the largest section of the head 56.2 of the screw 56.

[0047] The thickness of the movable wall 36 and the spacing between the head 56.2 of the screw 56 and the fixed part 40 (more particularly the first or second lateral rim 54) are adjusted so that in the undeformed state of the movable wall 36, the latter is pressed against the first and second lateral rims 54 and the head 56.2 of each screw 56 is flush with the outer face F36' of the movable wall 36.

[0048] According to a feature of the invention, the first and second holding elements 52.1, 52.2 are positioned on the fixed part 40 so that they are housed respectively in the first and second slots 50.1, 50.2 and hold the movable wall in the closed position as long as the pressure in the inner zone ZI is less than the given pressure value and the movable wall 36 has not reached the given deformed state and that they are no longer housed in the first and second slots 50.1, 50.2 and no longer hold the movable wall 36 in the closed position as soon as the pressure in the inner zone ZI is greater than or equal to the given pressure value and the movable wall 36 has reached the given deformed state. According to one arrangement, each of the first and second slots 50.1, 50.2 extends between a first end E1, opening at the first or second lateral edge 36.3, 36.4, as well as a second end E2 opposite the first end E1 and has a length (distance between the first and second ends E1, E2) such that each of the first and second holding elements 52.1, 52.2 is positioned at the level of the second end E2 of the first or second slot 50.1, 50.2 in which it is housed when the movable wall 36 is in the undeformed state.

[0049] According to one configuration, each of the first and second slots 50.1, 50.2 has a median axis A50, connecting the first and second ends E1, E2, which forms an angle less than or equal to 20° with respect to a vertical plane and perpendicular to the vertical median plane PMV. According to one arrangement, the first and second slots 50.1, 50.2 are symmetrical with respect to the vertical median plane PMV. The first and second slots 50.1, 50.2 are separated from the second transverse edge 36.2 by a distance less than 1 / 3 of the length of the movable wall 36 which corresponds to the distance separating the first and second transverse edges 36.1, 36.2.

[0050] Of course, the invention is not limited to this embodiment. Whatever the embodiment, the movable wall 36 is configured to deform in at least one direction of deformation, in particular in the event of overpressure in the interior zone ZI, so that first and second opposite edges, intersecting with the direction of deformation, come together, the fixed part 40 to which the movable wall 36 is connected being substantially non-deformable. In addition, the holding system 48 comprises at least one first slot 50.1 passing through the movable wall 36 and opening at one of the first and second opposite edges of the movable wall 36 as well as, for each slot 50.1, a first holding element 52.1 secured to the fixed part 40, positioned at one of the sides of the opening 32 and configured to cooperate with the first slot 50.1 when the movable wall 36 is in the closed position and in an undeformed state. The first holding element 52.1 and the first slot 50.1 are configured such that the first holding element 52.1 is housed in the first slot 50.1 and holds the movable wall 36 in the closed position as long as the pressure in the inner zone ZI is lower than the given pressure value and the movable wall 36 has not reached the given deformed state and the first holding element 52.1 is no longer housed in the first slot 50.1 and no longer holds the movable wall 36 in the closed position as soon as the pressure in the inner zone ZI is greater than or equal to the given pressure value and the movable wall 36 has reached the given deformed state.

[0051] According to one configuration, the direction of deformation is substantially perpendicular to the first and second lateral edges 36.3, 36.4. In addition, the holding system 48 comprises at least one slot opening onto one of the first and second lateral edges 36.3, 36.4. According to one arrangement, the holding system 48 comprises first and second slots 50.1, 50.2 opening onto each of the first and second lateral edges 36.3, 36.4, as illustrated in the figures 5, 7 And 8 .

[0052] According to another configuration, the direction of deformation is substantially perpendicular to the first and second transverse edges 36.1, 36.2, the articulation 38 which connects the movable wall 36 and the fixed wall being positioned at the level of the first transverse edge 36.1. In addition, the holding system 48 comprises a slot opening onto the second transverse edge 36.2 opposite that where the articulation 38 is positioned.

[0053] Whatever the embodiment, each holding system according to the invention has a smaller footprint, costs and mass than the locking systems of the prior art.

Claims

1. Aircraft including at least one pressure-relief device including at least one fixed part (40) as well as at least one mobile wall (36) configured to occupy a closed position in which the mobile wall (36) blocks an opening (32) and isolates interior and exterior zones (ZI, ZE) on respective opposite sides of the mobile wall (36) as well as an open position in which the mobile wall (36) at least partly frees the opening (32), the mobile wall (36) having an interior face (F36) oriented toward the interior zone (ZI) and an exterior face (F36') oriented toward the exterior zone (ZE), the pressure-relief device including at least one articulation (38) connecting the mobile wall (36) and the fixed part (40) as well at least one retaining system (48) configured to retain the mobile wall (36) in the closed position as long as a pressure in the interior zone (ZI) is lower than a given pressure value, the mobile wall (36) having at least one edge (36.1 to 36.4), the mobile wall (36) being configured to be deformed so that the mobile wall (36) occupies a given deformed state if the pressure in the interior zone (ZI) is at the given pressure value, characterized in that the retaining system (48) includes at least one first slot (50.1) through the mobile wall (36) opening at the level of the edge of the mobile wall (36) as well as, for each slot (50.1), a first retaining element (52.1) fastened to the fixed part (40), the first retaining element (52.1) and the first slot (50.1) being configured so that: - the first retaining element (52.1) is accommodated in the first slot (50.1) and retains the mobile wall (36) in the closed position as long as the mobile wall (36) is not in the given deformed state, - the first retaining element (52.1) is no longer accommodated in the first slot (50.1) and no longer retains the mobile wall (36) in the closed position as soon as the mobile wall (36) is in the given deformed state, in that each retaining element (52.1, 52.2) takes the form of a screw (56) that includes a body (56.1) screwed into the fixed part (40) as well as a milled head (56.2), and in that each slot (50.1, 50.2) has an edge surface (58) that is flared from the interior face (F36) to the exterior face (F36') of the mobile wall (36), the head (56.2) having a section greater than the smallest section of the slot (50.1, 50.2) in which the retaining element (52.1, 52.2) is accommodated.

2. Aircraft as claimed in claim 1, characterized in that the mobile wall has first and second transverse edges (36.1, 36.2) as well as first and second lateral edges (36.3, 36.4), the articulation (38) being positioned at the level of the first transverse edge (36.1), in that the mobile wall (36) is configured to be deformed in a deformation direction substantially perpendicular to the first and second transverse edges (36.1, 36.2) so that the first and second transverse edges (36.1, 36.2) are moved closer together when the mobile wall (36) is deformed, and in that the retaining system (48) includes at least one slot (50.1, 50.2) opening onto one of the first and second lateral edges (36.3, 36.4).

3. Aircraft as claimed in the preceding claim, characterized in that the retaining system (48) includes first and second slots (50.1, 50.2) opening onto each of the first and second lateral edges (36.3, 36.4).

4. Aircraft as claimed in the preceding claim, characterized in that the mobile wall (36) is substantially symmetrical with respect to a vertical median plane (PMV) substantially perpendicular to the first and second transverse edges (36.1, 36.2) and in that the first and second slots (50.1, 50.2) are substantially symmetrical with respect to the vertical median plane (PMV).

5. Aircraft as claimed in the preceding claim, characterized in that the mobile wall (36) has a length corresponding to a distance separating the first and second transverse edges (36.1, 36.2) and in that the first and second slots (50.1, 50.2) are separated from the second transverse edge (36.2) by a distance less than 1 / 3 the length of the mobile wall (36).

6. Aircraft as claimed in claim 4 or 5, characterized in that each of the first and second slots (50.1, 50.2) extends between a first end (E1) opening at the level of the first or second lateral edge (36.3, 36.4) as well as a second end (E2) opposite the first end (E1) and has a median axis (A50) connecting the first and second ends (E1, E2) at an angle less than or equal to 20° to a vertical plane and perpendicular to the vertical median plane (PMV).

7. Aircraft as claimed in any one of the preceding claims, characterized in that the articulation (38) includes at least two deformable connecting lugs (42) including a first part (42.1) fastened to the mobile wall (36), a second part (42.2) fastened to the fixed part (40) as well as an omega-shape intermediate part (42.3) connecting the first and second parts (42.1, 42.2).

8. Aircraft as claimed in the preceding claim, characterized in that each connecting lug (42) is made of a material that is deformed plastically when the mobile wall (36) moves from the closed position to the open position.