Thrust reverser with movable grilles and recess-mounted hoods

Description

Technical field

[0001] The invention relates to the field of thrust reversers for aircraft propulsion units, comprising movable grids. State of the prior art

[0002] Document WO 2014 / 091140 A1 describes a prior art thrust reverser with moving grids corresponding to the preamble of the first claim.

[0003] The inverter described in the aforementioned document has a “D” architecture, known by the English name “D-Duct”, comprising two half-assemblies which can be moved between a closed position, or flight position, and an open position intended for maintenance of the propulsion unit.

[0004] In the closed position, external covers of the half-assemblies cooperate with the grids so as to form a coupling movable in translation between a forward position allowing a thrust to be generated and a retracted position allowing a counter-thrust to be generated. For this purpose, the reverser comprises connecting means comprising a groove formed by the grids and a knife carried by the covers. When the half-assemblies are moved from the open position to the closed position, the knife is housed in the groove. The half-assemblies are then held in the closed position by locks.

[0005] Such connecting means and such locks do not, as such, ensure satisfactory maintenance of the connection between the hoods and the grilles, taking into account in particular the dynamic loads applied to the coupling. Statement of the invention

[0006] An object of the invention is to provide a thrust reverser capable of improving and securing the connection of the cowls with the grids in all phases of operation of the reverser, in particular when the coupling is in the forward position, in the rearward position or in any intermediate position.

[0007] For this purpose, the invention relates to a thrust reverser for an aircraft propulsion unit, comprising a fixed part, two cowls and deflection grilles, each of the cowls being connected to the fixed part by a pivot connection so as to be able to be moved between a closed position and an open position intended for the maintenance of the propulsion unit, the reverser comprising connecting means comprising one or more tabs formed by the cowls or respectively by the grilles and at least one groove formed by the grilles or respectively by the cowls, the connecting means being configured so that the tab(s) fit into the at least one groove when the cowls are moved from the open position to the closed position so that, in the closed position,the hoods and the grilles form a movable coupling relative to the fixed part in translation along a longitudinal axis between an advanced position allowing the propulsion unit to generate thrust and a retracted position allowing the propulsion unit to generate counter-thrust.,

[0008] According to the invention, the inverter comprises tension members connected to the grids and being configured so as to exert a plating stress on the tongue(s) in the at least one groove.

[0009] Connecting the tensioning members to the grids makes it possible to obtain a plating stress capable of effectively maintaining the tongue(s) in the at least one groove in all phases of operation of the inverter, whether the coupling is in the forward position, the backward position or an intermediate position and when moving the coupling between these different positions.

[0010] This results in improved maintenance of the connection between the hoods and the grilles and therefore increased safety.

[0011] The tension members are preferably configured to cooperate with the covers and / or with one or more force transmission parts.

[0012] Preferably, the covers comprise a frame forming the tongue(s), or respectively the at least one groove, the tensioning members being configured to cooperate with the frame of the covers or with one or more force transmission parts carried by the frame of the covers.

[0013] The tensioning members can thus act directly on the connecting means or on one or more transmission parts acting directly on the connecting means.

[0014] This further improves the bond between the hoods and the grilles.

[0015] In one embodiment, the tensioning members comprise at least one lock.

[0016] In one embodiment, the tensioning members comprise at least one compass comprising at least two connecting rods articulated to each other, one of the connecting rods being connected to the grids, the other connecting rod being connected to one of the covers.

[0017] The tensioning members may include both such a lock and such a compass.

[0018] In an embodiment in which the tensioning members comprise at least one such compass, the compass is configured to take a first configuration when the covers are in the closed position and a second configuration when the covers are in the open position, the inverter comprising a locking member making it possible to lock the compass in the first configuration.

[0019] In this case, the inverter preferably includes a control mechanism for unlocking the compass so that it can be placed in the second configuration.

[0020] The control mechanism may include a cable and a handle configured such that actuation of the handle exerts traction on the cable resulting in movement of the locking member.

[0021] According to a first type of embodiment, the inverter comprises one or more force transmission parts, the tension members cooperating with this or these force transmission parts so as to exert said plating stress.

[0022] Preferably, the inverter comprises one or more straps forming said force transmission part(s), each of the straps extending radially outside the connecting means and circumferentially around the longitudinal axis.

[0023] Preferably, each of the straps includes two circumferential ends that are each configured to be connected to the grids by a respective one of the tensioning members such that the tensioning members can exert a circumferential stress on the straps.

[0024] In an embodiment in which the tensioning members comprise at least one lock, at least one of the circumferential ends of at least one of said straps is connected to said lock.

[0025] In an embodiment in which the tensioning members comprise at least one compass as defined above, at least one of the circumferential ends of at least one of said straps is connected to said compass so as to preserve the connection between this strap and the grilles when the covers are moved between the open and closed positions.

[0026] In order to withstand the mechanical and thermal stresses they undergo during operation of the propulsion unit, the straps preferably comprise a metallic material.

[0027] In one embodiment, the straps include primary straps and secondary straps configured such that the plating stress is exerted by the primary straps when the primary straps are operational and by the secondary straps in the event of breakage or failure of the primary straps.

[0028] According to a second type of embodiment, the tensioning members cooperate directly with the hoods, preferably with said frame of the hoods.

[0029] Thus, in an embodiment in which the tensioning members comprise at least one compass as defined above, the compass is configured to exert a circumferential stress on one of the covers, more preferably on said frame of this cover.

[0030] The first and second types of embodiments described above and, more generally, the different characteristics described in this document can be combined with each other.

[0031] It is stated above that the means of connection include “ one or more tabs formed by the covers or respectively by the grilles and at least one groove formed by the grilles or respectively by the covers » and that, preferably, « the covers comprise a frame forming the tongue(s), or respectively the at least one groove”.

[0032] Thus, according to a first variant, the at least one groove is formed by the grids and each of the covers, preferably said frame of these covers, forms one or more of said tabs.

[0033] According to a second variant, each of the covers, preferably said frame of these covers, forms at least one groove and the grids form said tab(s).

[0034] A third variant consists of combining the two aforementioned variants.

[0035] For example, the grilles may form both one or more grooves and one or more tabs and each of the covers, in particular said frame of these covers, may form one or more complementary grooves and / or one or more tabs.

[0036] The invention also relates to a nacelle comprising such an inverter, a propulsion assembly comprising such a nacelle and an aircraft comprising such a propulsion assembly.

[0037] According to another aspect, the invention relates to a method of plating the tongue(s) in the at least one groove of an inverter as defined above.

[0038] In one embodiment, this method comprises a step of applying a circumferential stress by the tension members on the covers or on one or more force transmission parts.

[0039] Other advantages and characteristics of the invention will appear on reading the detailed, non-limiting description which follows. Brief description of the drawings

[0040] The following detailed description refers to the attached drawings in which: [ Fig. 1 ] is a schematic longitudinal sectional view of an aircraft propulsion system comprising a bypass turbojet engine and a thrust reverser in a direct thrust configuration; [ Fig. 2 ] And [ Fig. 3 ] are schematic perspective views of the propulsion system of the figure 1 , in direct thrust configuration; [ Fig. 4 ] is a schematic perspective view of the propulsion system of the figure 1, in a maintenance configuration; [ Fig. 5 ] is a schematic perspective view of the propulsion system of the figure 1 , in a reverse thrust configuration; [ Fig. 6 ] And [ Fig. 7 ] are schematic half-views in longitudinal section of the reverser of the propulsion unit of the figure 1 , respectively in direct thrust configuration and in reverse thrust configuration; [ Fig. 8 ] is a schematic perspective view of an assembly forming grids and a cover of the reverser of the propulsion assembly of the figure 1 , this set including a rear frame of the grilles and a front frame of the hood in the maintenance configuration of the figure 4 ; [ Fig. 9 ], [ Fig. 10 ] And [ Fig. 11 ] are schematic perspective views of a first circumferential end of the entire figure 8according to a first embodiment, showing a strap carried by the front frame of the hood and a first tensioning member connected to a first end of this strap; [ Fig. 12 ] is a schematic view of a half-part of the reverser of the propulsion assembly of the figure 1 , including the whole of the figure 8 according to the first embodiment of the figures 9-11 , this figure showing said first tensioning member and a second tensioning member connected to a second end of the strap; [ Fig. 13 ] is a schematic perspective view of a second circumferential end of said front frame of the hood of the assembly of the figure 8 ; [ Fig. 14 ] And [ Fig. 15 ] are schematic views of the second circumferential end of the entire figure 8 , showing the second tensioning organ of the figure 12according to a first variant respectively in an unlocking position and in a locking position; [ Fig. 16 ] And [ Fig. 17 ] are schematic views of said first circumferential end of the entire figure 8 , showing the first tensioning member respectively in a disengaged position and in an engaged position; [ Fig. 18 ] And [ Fig. 19 ] are schematic views of the second circumferential end of the entire figure 8 , showing the second tensioning organ of the figure 12 according to a second variant respectively in an unlocking position and in a locking position; [ Fig. 20 ] is a schematic view of a half-part of the reverser of the propulsion assembly of the figure 1according to a second embodiment, comprising a rear grille frame, a front hood frame, a strap carried by the front frame, as well as two tensioning members connected to the grilles and cooperating with the strap, one of the tensioning members comprising a compass, the other tensioning member comprising a lock; [ Fig. 21 ] And [ Fig. 22 ] are partial schematic perspective views of the inverter half-part of the figure 20 , showing the compass and the hood respectively in a first position corresponding to the maintenance configuration of the figure 4 and in a second position corresponding to the flight configuration of the figures 1-3 ; [ Fig. 23 ] is a schematic view of a front hood frame receiving two superimposed straps; [ Fig. 24 ] is a schematic perspective view of a connecting member for the straps of the figure 23 ; [ Fig. 25] is a schematic view of a half-part of the reverser of the propulsion assembly of the figure 1 according to a third embodiment, comprising a rear grille frame, a front hood frame as well as two tension members connected to the grilles and cooperating with the front hood frame, one of the tension members comprising a compass, the other tension member comprising a lock; [ Fig. 26 ] And [ Fig. 27 ] are partial schematic perspective views of the inverter half-part of the figure 25 , showing the compass and the hood respectively in a first position corresponding to the maintenance configuration of the figure 4 and in a second position corresponding to the flight configuration of the figures 1-3 , these figures showing a mechanism for locking the compass when the cover is in the second position. Detailed description of embodiments

[0041] THE figures 1 to 7include a reference frame X1-X2-X3 defining respectively longitudinal, vertical and lateral directions orthogonal to each other. Figures 8-23 And 25-27 include a reference frame X4-X5-X6 defining respectively longitudinal, radial and circumferential directions orthogonal to each other.

[0042] THE figures 1 to 5 show a propulsion unit 1 having a longitudinal central axis A1.

[0043] Subsequently, the terms “front” and “rear” are defined relative to a direction S1 of flow of gases through the propulsion unit 1 along the axis A1 when the latter generates thrust.

[0044] The propulsion unit 1 includes a turbomachine 2 (visible on the figure 1 ), a nacelle 3 and a mast 4 (visible on the figures 2 to 5 ) allowing the propulsion unit 1 to be connected to a wing of an aircraft (not shown).

[0045] In the example of the figure 1, the turbomachine 2 is a double-flow turbojet comprising, from front to rear, a fan 5, a low-pressure compressor 6, a high-pressure compressor 7, a combustion chamber 8, a high-pressure turbine 9 and a low-pressure turbine 10. The compressors 6 and 7, the combustion chamber 8 and the turbines 9 and 10 form a gas generator.

[0046] The turbojet 2 comprises a fan casing 11 connected to the gas generator by structural arms 12.

[0047] The nacelle 3 comprises a front section 15 forming an air inlet, a middle section 16 which comprises fan cowls surrounding the fan casing 11 and a rear section 17.

[0048] In a manner known per se, during operation of the turbojet 2, an air flow 20 enters the propulsion unit 1 through the air inlet 15, passes through the fan 5 and then divides into a central primary flow 20M and a secondary flow 20N. The primary flow 20M flows in a primary gas circulation duct 21M within the gas generator. The secondary flow 20N flows in a secondary duct 21N surrounding the gas generator and delimited radially outwards by the nacelle 3.

[0049] Nacelle 3 includes a thrust reverser formed by the rear section 17.

[0050] In reference to the figure 3, the rear section 17 comprises two half-assemblies 25A and 25B of semi-cylindrical shape and symmetrical with respect to each other relative to a vertical plane P1 passing through the axis A1 and parallel to the vertical direction X2. Thus, the half-assemblies 25A and 25B extend laterally on either side of the vertical plane P1 and in particular on either side of the mast 4.

[0051] In reference to the figure 4 which shows the half-assembly 25A in an open position, the half-assembly 25A comprises an internal fairing 30 and an external cover 31.

[0052] The internal fairing 30, commonly referred to as the “fixed internal structure”, comprises a lower junction wall 32 also called an “island” or “six o’clock” “bifurcation”, a central wall 33 of semi-annular shape and an upper junction wall 34 also called an “island” or “twelve o’clock” “bifurcation”.

[0053] The cover 31 extends radially outside the central wall 33 of the internal fairing 30 and also has a semi-annular shape.

[0054] The central wall 33 of the internal fairing 30 and the cover 31 radially define between them a circumferential sector of the secondary duct 21N, this sector extending circumferentially between the lower junction wall 32 and the upper junction wall 34 of the internal fairing 30.

[0055] The half-assembly 25A is connected, by one of its circumferential ends, to a fixed part of the propulsion assembly 1, in this case to a beam 41 (visible on the figures 12 , 20 And 25 ) secured to the mast 4, according to a pivot connection so as to be able to be moved between a closed position illustrated in figure 3 and the opening position of the figure 4 .

[0056] In this example, the movement of the half-assembly 25A between the closed and open positions corresponds to a simultaneous movement of the cover 31 and the internal fairing 30 which are integral with each other in rotation around the axis formed by said pivot connection. In other words, the inverter has in this example a “D” architecture.

[0057] The open position allows a maintenance operator to access turbojet 2.

[0058] The above description applies by analogy to the half-assembly 25B.

[0059] To hold the half-assemblies 25A and 25B in the closed position ( figure 3 ), these are connected to each other using locks (not shown) mounted at six o'clock, vertically opposite mast 4.

[0060] In reference to the figures 5 to 7, the inverter comprises grids 40 and connecting means 50 configured to connect the cover 31 of each of the half-assemblies 25A and 25B to the grids 40 when the half-assemblies 25A and 25B are in the closed position.

[0061] The hoods 31 and the grids 40 thus connected form a coupling mobile in translation along the axis A1 between an advanced position illustrated in figures 2 , 3 And 6 and a retracted position illustrated in figures 5 And 7 .

[0062] In this example, this coupling is movable relative to said fixed part of the propulsion assembly 1 and relative to the fixed internal structure 30 of each of the half-assemblies 25A and 25B.

[0063] In the forward position ( figures 2 , 3 And 6), the grids 40 are housed in a circumferential space formed by the middle section 16 and a front end of the covers 31 rests on a rear end of the middle section 16.

[0064] In the forward position, the secondary conduit 21N channels the secondary flow 20N towards the rear of the propulsion unit 1 so as to generate thrust (see figure 6 ).

[0065] In the rearward position ( figures 5 And 7 ), the front end of the covers 31 and the rear end of the middle section 16 are spaced apart from each other by a distance Y1 defining a radial opening. The grids 40 extend longitudinally between the rear end of the middle section 16 and the front end of the covers 31 and circumferentially around the axis A1 so as to extend through said radial opening.

[0066] In a manner known per se, each of the half-assemblies 25A and 25B comprises closing flaps 45 articulated on the cover 31 and connecting rods 46 which are each connected on the one hand to a respective one of the flaps 45 and on the other hand to the central wall 33 of the fixed internal structure 30 so that, when the cover 31 passes from the advanced position to the retracted position, the flaps 45 deploy radially in the secondary duct 21N so as to close this duct 21N (see figure 7 ).

[0067] The secondary flow 20N is thus directed towards the grids 40 which deflect this flow towards the front of the propulsion unit 1 in order to generate counter-thrust.

[0068] To allow the coupling to be moved between the forward and rearward positions, the grids 40 and the hoods 31 are connected to beams 41, 42 and 43 (see figures 12 , 20 And 25) according to a sliding connection and the covers 31 are driven in translation by actuators (not shown) such as jacks housed in the circumferential space formed by the middle section 16. The connection means 50 make it possible to drive the grids 40 under the action of the movement of the covers 31.

[0069] In this example, the grids 40 comprise two half-parts of semi-cylindrical shape and symmetrical with respect to each other relative to the vertical plane P1, each of these half-parts having a circumferential dimension substantially identical to the circumferential dimension of the covers 31.

[0070] Thus, each of the half-parts of the grids 40 cooperates with a respective one of the covers 31 when the latter are in the closed position.

[0071] The following description relates to the half-assembly 25A as well as to the corresponding half-part of the grids 40 and applies by analogy to the half-assembly 25B and to the other half-part of the grids 40.

[0072] There figure 8 shows on the one hand a front frame 52 of the hood 31 in the open position and on the other hand a rear frame 53 of the grilles 40 provided to cooperate with the hood 31 when the latter is placed in the closed position.

[0073] There figure 8 also shows two side members 54 and 55 making it possible in particular to connect the rear frame 53 to a front frame (not shown) of the grids 40.

[0074] In the embodiment of the figure 8 , the front frame 52 of the hood 31 forms a ring section having two circumferential ends and comprises a tongue 57 which extends circumferentially between these two ends and radially inwards towards the rear frame 53 of the grilles 40.

[0075] When the cover 31 is in the closed position, the tab 57 extends circumferentially around the axis A1.

[0076] In this example, the tab 57 extends substantially over the entire circumferential dimension of the front frame 52.

[0077] The rear frame 53 of the grids 40 also forms a ring section having two circumferential ends and comprises a groove 58 extending circumferentially between these two ends.

[0078] The tongue 57 and the groove 58 have a complementary shape so that, when the cover 31 is moved from the open position ( figures 8 And 9 ) to the closed position ( Figures 10 and 11 ), the tongue 57 fits into the groove 58.

[0079] The connecting means 50 thus make it possible to secure the cover 31 with the grids 40 by embedding so as to form said coupling.

[0080] The invention relates more specifically to loading means making it possible to apply a pressing stress to the tongue 57 in the groove 58 in order to improve and secure the connection made by these connection means 50.

[0081] In the embodiment of the figures 8 to 24 , the loading means comprise a strap 60 and two tensioning members 701 / 704 and 702 / 703 of this strap 60.

[0082] In reference to the figure 9 , the front frame 52 of the hood 31 comprises an element 61 forming radially inwards the tongue 57 and defining radially outwards a sliding surface.

[0083] In this example, the front frame 52 of the cover 31 also comprises a retaining part 62 such as a bracket extending radially outside the element 61 so as to define a radial space between the sliding surface and a radially internal surface of this retaining part 62 (see figures 9 And 10 ).

[0084] The strap 60 is housed within this radial space, the radial dimension of which is greater than the thickness of the strap 60.

[0085] The strap 60 thus extends radially outside the tongue 57 and longitudinally at the same level as the latter.

[0086] When the cover 31 is in the closed position, the strap 60 extends circumferentially around the axis A1 so as to form two circumferential ends.

[0087] Each circumferential end of the strap 60 is connected to a respective one of the tension members 701 / 704 and 702 / 703.

[0088] In reference to the figure 12, the circumferential end of the strap 60 located vertically at the top, near the beam 41, is called "first end" and that located vertically at the bottom is called "second end". Similarly, the circumferential end of the front frame 52 of the hood 31 located vertically at the top, near the beam 41, is called "first end" and that located vertically at the bottom is called "second end". In the following, the tensioning member connected to the first, respectively to the second, end of the strap 60 is called "first tensioning member", respectively "second tensioning member".

[0089] In the embodiment of the figures 8 to 17, the first tensioning member 701 comprises a first attachment element 71 forming a hook and a second attachment element 72 forming a cylinder. The first attachment element 71 is fixed to the first end of the strap 60 while the second attachment element 72 is integral with the rear frame 53 of the grids 40.

[0090] In the embodiment of the figures 8 to 17 , the second tensioning member 702 is a lock comprising a first part secured to the second end of the strap 60 and a second part secured to the rear frame 53 of the grids 40.

[0091] Generally, the first part of the lock 702 comprises a first attachment element 73 forming a hook intended to cooperate with a second attachment element 74 such as a cylinder forming the second part of this lock.

[0092] The lock 702 includes an actuator 75 in the form of a locking / unlocking handle.

[0093] In reference to the figures 14 and 15 , the first part of the lock 702 is connected to an articulation member 63 fixed to the second end of the strap 60. The first part of the lock 702 comprises a first articulation 76 defining an axis of rotation of both the hook 73 relative to the articulation member 63 and a first end of a link 79 relative to the articulation member 63. The first part of the lock 702 also comprises a second articulation 77 defining an axis of rotation of the hook 73 relative to the handle 75 and a third articulation 78 defining an axis of rotation of the handle 75 relative to a second end of the link 79.

[0094] The first tensioning member 701, the lock 702 and the strap 60 constitute loading means enabling the plating stress to be generated by manual actuation of the handle 75 of the lock 702.

[0095] To do this, after the cover 31 has been placed in the closed position, the handle 75 is actuated so as to change the lock 702 from the unlocked state illustrated in figure 14 in the locked state shown in figure 15 .

[0096] To allow good positioning of the strap 60 during this locking stroke despite the floating mounting of the first part of the lock 702, the articulation member 63 or another element of the first part of the lock 702 is in this example configured to bear on a stop formed by the front frame 52 of the cover 31. By way of example, this stop can be formed by one end of an oblong opening allowing the articulation member 63 to slide relative to the front frame 52.

[0097] During this locking stroke, the lock 702 exerts a tensile force on the second end of the strap 60 so that the hook 71 of the first tensioning member 701 comes to bear on the cylinder 72, causing the first tensioning member 701 to pass from the disengaged state illustrated in figure 16 in the state of engagement illustrated in the figure 17 .

[0098] In order to ensure the engagement of the cylinder 72 in the hook 71, the front frame 52 of the hood 31 comprises in the example of the figure 9 a radial stop 66.

[0099] In an embodiment not shown, a prestressing member is interposed radially between the hook 71 and the radial stop 66, for example a spring fixed to the hook 71.

[0100] The strap 60 and the tensioning members 701 and 702 are configured so that the first tensioning member 701 reaches the engaged state ( figure 17) during a first part of the locking stroke, i.e. before the lock 702 reaches the locking state ( figure 15 ).

[0101] During a second part of the locking stroke, the two tension members 701 and 702 exert on the strap 60 an increasing circumferential stress which presses the strap 60 onto the sliding surface formed by the front frame 52 of the cover 31. This surface allows relative circumferential sliding of the strap 60 relative to the frame 52.

[0102] The plating of the towed strap 60 makes it possible to generate the plating stress of the tongue 57 in the groove 58.

[0103] The strap 60 thus forms a force transmission part making it possible to produce a mechanical action at the level of the connecting means 50, that is to say in a transverse plane crossing the connecting means 50.

[0104] THE figures 18 And 19show another type of lock 703 which can form the second tensioning member of the entire figure 12 .

[0105] Unlike the lock 702, the first part of the lock 703 is not mounted floating but is connected to a part 64 of the front frame 52.

[0106] In the example of the figures 18 And 19, the lock 703 comprises four articulations 81, 82, 83 and 84 and three links 85, 86 and 87. The articulation 81 defines an axis of rotation of a first end of the link 85 relative to the articulation member 63 fixed to the strap 60. The articulation 82 defines an axis of rotation of a second end of the link 85 relative to a first end of each of the links 86 and 87. The articulation 83 defines a common axis of rotation for a second end of the link 86, the hook 73 and the handle 75. The articulation 84 defines an axis of rotation of a second end of the link 87 relative to the part 64 of the front frame 52.

[0107] In the various embodiments described above, the tensioning members 701, 702 and 703 form detachable joining means, capable of connecting the strap 60 to the rear frame 53 of the grids 40 when the cover 31 is in the closed position and of detaching it, at least partially, from this rear frame 53 when the cover 31 is moved towards the open position.

[0108] The method of realization of the figures 20 to 22 differs from the embodiments described above in that the first tensioning member 704 forms a means of permanent joining of the strap 60 to the rear frame 53 of the grids 40.

[0109] In reference to the figure 21 , the first tensioning member 704 comprises a connecting piece 91 fixed to the first end of the strap 60 and connected to two connecting rods 92 and 93 articulated to each other so as to form a compass.

[0110] More specifically, the first tension member 704 comprises an articulation element 95 such as a shaft to which the connecting piece 91 and a first end of each of the connecting rods 92 and 93 are connected in a pivot connection.

[0111] The second end of the connecting rod 92 is articulated on the front frame 52 of the hood 31 while the second end of the connecting rod 93 is articulated on the rear frame 53 of the grilles 40.

[0112] Such a tensioning member 704 makes it possible to preserve the connection between the strap 60, the grids 40 and the cover 31 when the latter is moved between the open position ( figure 21 ) and the closing position ( figure 22 ). This makes it possible in particular to avoid any problem of engagement and disengagement of detachable joining means such as the member 701 of the figures 16 And 17 .

[0113] In the closed position, the connecting rod 93 extends in continuity with the connecting piece 91 and the strap 60, ensuring good distribution of the tensile forces.

[0114] The tension member 704 of the figures 20 to 22 also makes it possible to limit the circumferential sliding amplitude of the strap 60 when the cover 31 moves between the open and closed positions.

[0115] In this example, the connecting rods 92 and 93 have a stiffness allowing them to contribute to the positioning of the cover 31 and the half-assembly 25A when it is opened and to ensure its guidance when it is closed in order to improve the alignment of the tongue 57 relative to the groove 58.

[0116] In the preceding examples, the hood 31 is equipped with a single strap 60.

[0117] A second emergency strap can be used, in particular to overcome access difficulties during routine maintenance.

[0118] So, in the example of the figure 23 , the front frame 52 of the hood 31 carries two straps 60A and 60B superimposed on each other.

[0119] Strap 60A forms a primary strap implemented in the manner described above, while strap 60B forms a secondary backup strap configured to exert the plating stress in the event of breakage or failure of primary strap 60A.

[0120] To do this, the straps 60A and 60B may be connected by one of their circumferential ends to a tensioning member configured to exert a differential circumferential stress.

[0121] There figure 24 shows a tensioning member 100 capable of providing such a function and which can be mounted in place of the tensioning member 704 of the figures 20 to 22 .

[0122] In this example, the first end of the strap 60A is attached to a hinge member 101A and the first end of the strap 60B is attached to a hinge member 101B.

[0123] Connecting rods 102 and 103, having a function similar to the connecting rods 92 and 93 of the figure 21 , are articulated to each other by a first shaft (not shown) secured to a first end of the connecting rod 103.

[0124] The articulation elements 101A and 101B are articulated around a second shaft (not shown) which is integral with the first end of a connecting rod 103 and adjacent to the first shaft.

[0125] The second end of the connecting rod 102 is articulated on the front frame 52 of the hood 31 while the second end of the connecting rod 103 is articulated on the rear frame 53 of the grilles 40.

[0126] THE figures 25 to 27 illustrate loading means which are distinguished from those described above with reference to the figures 8 to 24 in that tension members act directly on the front frame 52 of the hood 31, without using a force transmission part such as a strap.

[0127] In reference to the figure 26 , the loading means comprise a first tension member 705 formed in this example by two connecting rods 201 and 202 and three articulation elements 211, 212 and 213.

[0128] A first end of the connecting rod 201 is articulated to the front frame 52 of the hood 31 by the articulation element 211 and a first end of the connecting rod 202 is articulated to the rear frame 53 of the grilles 40 by the articulation element 213. The connecting rods 201 and 202 are articulated to each other by their second end via the articulation element 212.

[0129] The connecting rods 201 and 202 thus form a compass which can move from an open configuration illustrated to the figure 26when the cover 31 is in the open position to a closed configuration illustrated in figure 27 when the cover 31 is in the closed position, and vice versa.

[0130] To lock the compass in the closed configuration, the reverser comprises a locking mechanism comprising a locking member 220, two articulation elements 221 and 22 and an elastic member such as a spring 223.

[0131] The locking member 220 is articulated to the front frame 52 of the hood 31 by the articulation element 221 and comprises one end forming a hook configured to cooperate with the articulation element 213 secured to the rear frame 53 of the grilles 40.

[0132] The spring 223 is connected to the locking member 220 by the articulation element 222 so as to exert on the locking member 220 a locking force tending to make it pivot in a first direction of rotation around the articulation element 221.

[0133] The locking member 220 is configured so that, when the cover 31 is moved from the open position ( figure 26 ) to the closed position ( figure 27 ), the locking member 220 bears on the articulation element 213 so as to pivot in a second direction of rotation around the articulation element 221 and thus allow the hook to engage around the articulation element 213. The locking force exerted by the spring 223 makes it possible to lock the compass in the closed configuration.

[0134] In order to be able to disengage the locking member 220 relative to the articulation element 213 and then open the hood 31, the reverser is equipped with a control mechanism comprising in this example a cable 224 and an actuating handle 225.

[0135] A first end of the cable 224 is connected to the locking member 220 so that a traction of this cable 224, of a force greater than that produced by the spring 223, causes the locking member 220 to pivot in the second direction of rotation around the articulation element 221.

[0136] The actuating handle 225 is connected to the second end of the cable 224 and mounted at the second circumferential end of the front frame 52 of the hood 31. In the embodiment of the figure 25 , the loading means also comprise a lock 706 forming a second tensioning member.

[0137] The lock 706 comprises a first part secured to the second end of the front frame 52 of the hood 31 and a second part secured to the rear frame 53 of the grilles 40. In a manner similar to the lock 702 described above with reference to the figures 14 and 15, the first part of the lock 706 comprises a first attachment element forming a hook intended to cooperate with a second attachment element such as a cylinder forming the second part of this lock 706.

[0138] From the configuration of the figure 27 in which the cover 31 is in the closed position, the locking of the lock 706 results in the application by the tension members 705 and 706 of a circumferential stress on the front frame 52 of the cover 31, which generates said stress of pressing the tongue 57 into the groove 58.

[0139] Of course, the preceding description is not limiting and numerous variations can be made to these different embodiments without departing from the scope of the invention which is defined by the claims.

[0140] For example, the connecting means 50 may comprise one or more tabs formed by the grids 40 and one or more corresponding grooves formed by the front frame 52 of each of the covers 31 (not shown).

[0141] Furthermore, the preceding description applies by analogy to a mobile grid inverter having a “C” architecture, well known in the aeronautical field, in which the external covers of the rear section 17 open in the maintenance position independently of the parts of this section forming the secondary duct 21N (not shown).

Claims

1. Thrust reverser for an aircraft propulsion assembly (1), comprising a fixed portion (41), two cowls (31), and deflection grids (40), each of the cowls (31) being connected to the fixed portion (41) by a pivot joint so as to be movable between a closed position and an open position intended for maintenance of the propulsion assembly (1), the reverser comprising connection means (50) including one or more tabs (57) formed by the cowls (31) or respectively by the grids (40) and at least one groove (58) formed by the grids (40) or respectively by the cowls (31), the connection means (50) being configured such that the one or more tabs (57) fit into the at least one groove (58) when the cowls (31) are moved from the open position to the closed position so that, in the closed position, the cowls (31) and the grids (40) form an assembly movable relative to the fixed portion (41) in translation along a longitudinal axis (A1) between a forward position allowing the propulsion assembly (1) to generate thrust and a rearward position allowing the propulsion assembly (1) to generate reverse thrust, characterized in that it comprises tension members (701-706) connected to the grids (40) and configured to exert a clamping force of the one or more tabs (57) in the at least one groove (58).

2. Thrust reverser according to claim 1, wherein the tension members (701, 706) are configured to cooperate with the cowls (31) and / or with one or more force transmission parts (60).

3. Thrust reverser according to claim 1 or 2, wherein the cowls (31) comprise a frame (52) forming the one or more tabs (57), or respectively the at least one groove (58), the tension members (701-706) being configured to cooperate with the frame (52) of the cowls (31) or with one or more force transmission parts (60) carried by the frame (52) of the cowls (31).

4. Thrust reverser according to any one of claims 1 to 3, wherein the tension members (701-706) comprise at least one latch (702, 703, 706) and / or at least one link rod assembly (704; 705) comprising at least two rods (92, 93; 201, 202) articulated to each other, one of the rods (93; 202) being connected to the grids (40), the other rod (92; 201) being connected to one of the cowls (31).

5. Thrust reverser according to any one of claims 1 to 4, including the features of claim 2, comprising one or more straps (60) forming said force transmission part(s), each strap (60) extending radially outside the connection means (50) and circumferentially around the longitudinal axis (A1), each strap (60) comprising two circumferential ends each configured to be connected to the grids (40) by a respective one of the tension members (701-704) so that the tension members (701-704) can exert a circumferential force on the straps (60).

6. Thrust reverser according to claims 4 and 5, wherein at least one of the circumferential ends of at least one of said straps (60) is connected to said latch (702, 703, 706).

7. Thrust reverser according to claim 5 or 6, including the features of claim 4, wherein at least one of the circumferential ends of at least one of said straps (60) is connected to said link rod assembly (704) so as to maintain the connection between this strap (60) and the grids (40) when the cowls (31) are moved between the open and closed positions.

8. Thrust reverser according to any one of claims 5 to 7, wherein the straps comprise primary straps (60A) and secondary straps (60B) configured such that the clamping force is exerted by the primary straps (60A) when these are operational and by the secondary straps (60B) in the event of breakage or failure of the primary straps.

9. Thrust reverser according to any one of claims 1 to 8, including the features of claim 4, wherein the link rod assembly (705) is configured to take a first configuration when the cowls (31) are in the closed position and a second configuration when the cowls (31) are in the open position, the reverser comprising a locking member (220) for locking the link rod assembly (705) in the first configuration and a control mechanism (224, 225) for unlocking the link rod assembly (705) to allow it to be placed in the second configuration.

10. Method for clamping the one or more tabs (57) in the at least one groove (58) of a thrust reverser according to any one of claims 1 to 9.