A thrust reverser comprising at least one deployable membrane, as well as a membrane deployment mechanism arranged in a cavity of a movable reverser hood.

Abstract

The invention relates to a thrust reverser for an aircraft propulsion system, comprising a movable structure (29) having at least one reverser cover (33) having an upstream-opening cavity (54) delimited between a radially external wall (50) and a radially internal wall (52) of the reverser cover (33). The reverser also includes a membrane (58) for closing the secondary flow (21B), as well as a membrane deployment member (62) connected to this membrane (58), and designed to be arranged at least partially within the secondary flow (21B) when the movable structure is in its thrust reversing rearward position. According to the invention, when the movable structure (29) is in its forward direct thrust position, the membrane deployment member (62) is at least partially housed within the cavity (54) of the movable reverser cover (33). Figure for the abstract: Fig. 2

Description

Title of the invention: THRUST REVERSER COMPRISING AT LEAST ONE DEPLOYABLE MEMBRANE, AS WELL AS A MEMBRANE DEPLOYMENT DEVICE LOCATED IN A CAVITY OF A MOVABLE INVERTER COVER Technical field

[0001] The invention relates to the field of nacelles and thrust reversers for aircraft propulsion systems, and, more particularly, to thrust reversers equipped with deployable membranes to close the secondary vein. State of the prior art

[0002] Thrust reversers are devices for diverting the airflow passing through the propulsion unit forward, so as to shorten landing distances and limit the stress on the brakes on the landing gear.

[0003] The grid reversers currently used in the aeronautical sector comprise deflection grids integrated into a fixed or mobile structure of the reverser. The mobile structure of the reverser comprises one or more mobile reverser cowls, and it is mounted so as to be movable in translation relative to the fixed structure between a forward direct thrust position and a rearward thrust reversal position.

[0004] In the rearward thrust reversal position, to divert at least part of the secondary flow towards the grilles, the reverser is usually equipped with shutters, which, when deployed, at least partially close the secondary vein. In a known manner, this forces the air of the secondary flow radially outwards, towards the grilles, which then generate the counter-thrust air flow towards the front.

[0005] The flaps are generally pivotally mounted on the radially inner wall of the movable reverser cowls, this wall delimiting the secondary flow radially outwards. Thus, recesses are provided in this radially inner wall of the reverser cowls in order to receive the shutter flaps in the retracted position, as adopted in direct jet. However, in direct jet, the presence of the recesses and the flaps is a source of aerodynamic disturbances on the secondary flow. In addition, this presence locally limits the installation of an acoustic panel on the radially inner wall of the reverser cowls.

[0006] To provide a technical solution to these problems, it has been proposed to replace the shutters with one or more deployable membranes for closing the se- secondary. Such a design is known, for example, from document FR 3 076 864 Al.

[0007] There nevertheless remains a need to optimize the design of the means allowing the deployment of the sealing membranes, in the secondary vein. Indeed, it is essentially envisaged to use membrane deployment rods, articulated on the internal radial delimiting wall of the secondary vein, and thereby generating disturbances on the secondary flow in direct jet configuration. Presentation of the invention

[0008] To meet at least partially the need expressed above, the invention firstly relates to a thrust reverser for an aircraft propulsion unit, the reverser comprising a fixed structure equipped with a radially internal delimiting wall of a secondary vein of the propulsion unit intended to be crossed by a secondary flow, the reverser also comprising a mobile structure comprising at least one reverser cowl having a cavity open upstream and delimited between a radially external wall and a radially internal wall of the reverser cowl, the mobile structure being movable in translation relative to the fixed structure along a longitudinal central axis of the reverser,between an advanced direct thrust position and a retracted thrust reversal position in which the retracted radially internal wall of the reverser cowl reveals upstream an opening for passage of the secondary vein towards a flow deflection member, the reverser also comprising a membrane for closing the secondary vein, as well as a membrane deployment member connected to this membrane, and designed to be arranged at least partly in the secondary vein when the mobile structure occupies its retracted thrust reversal position. According to the invention, when the mobile structure occupies its advanced direct thrust position, the membrane deployment member is at least partly housed in the cavity of the mobile reverser cowl.

[0009] With this design specific to the present invention, in the direct jet configuration, the secondary flow is no longer aerodynamically disturbed by the membrane deployment members, such as connecting rods, because these members are housed in the movable reverser cowl. This results in a clear improvement in the overall performance of the propulsion unit, which corresponds to a result of technological research aimed at significantly improving the performance of aircraft and, in this sense, contributes to reducing the environmental impact of these aircraft (decarbonization).

[0010] The invention preferably provides at least one of the following optional technical features, taken alone or in combination.

[0011] Preferably, the inverter is designed so that when the mobile structure from its forward direct thrust position to its retracted thrust reversal position, the membrane deployment member is extracted from the cavity through an upstream opening of the latter.

[0012] Preferably, the membrane deployment member is a connecting rod, preferably taken from:

[0013] - a straight connecting rod;

[0014] - a curved connecting rod, for example in the general shape of a C or an S;

[0015] - a telescopic connecting rod, preferably associated with a control system comprising an actuating spring and a spring deployment control cable.

[0016] Preferably, the membrane deployment member comprises an end mounted in an articulated manner on the fixed structure of the inverter, preferably on a rear support frame of the flow diversion member.

[0017] Preferably, the membrane deployment member is connected to an upstream end of the radially internal wall, by means of at least one connecting member mounted articulated on the upstream end, preferably along a tangential or substantially tangentially oriented articulation axis, the deployment member being slidably mounted on this connecting member, preferably having a rail-shaped portion cooperating with the connecting member. The combination of the two movements permitted by the aforementioned means ensures both the upstream extraction of the deployment member from the cavity of the movable cover, as well as its radially inward immersion in the secondary vein.

[0018] According to another possibility, the reverser comprises a system for guiding the connecting rod deployment member, comprising a radially internal guide member, preferably mounted on the radially internal wall of the mobile reverser cover, as well as a radially external guide member, preferably mounted on the radially external wall of the mobile reverser cover, the radially internal guide member being preferentially arranged upstream of the radially external guide member. In this solution, it is thus the two guide members which, thanks to their positions and the fact that they follow the movement of the mobile cover, make it possible to force the deployment member to be extracted from the cavity of the mobile cover, while tilting to plunge radially inwards into the secondary vein.

[0019] Preferably, the inverter comprises at least one spring for assisting the movement of the membrane deployment member in the vein, and / or it comprises at least one spring for damping the end of movement of the deployment member, during a movement of the mobile structure from its forward direct thrust position to its retracted thrust reversal position. The nature of these springs, as well as their positions, can be multiple, for example provided on the mobile structure or the fixed structure, such as on the rear grid support frame.

[0020] Preferably, the flow deflection member comprises a membrane deployable using connecting rods, and the inverter comprises stop means for said connecting rods, preferably arranged on the radially external wall of the movable inverter cover, or for example on the rear support frame of the flow deflection member.

[0021] Preferably, the inverter includes stop means for the membrane deployment member, preferably arranged on the radially outer wall of the movable inverter cover.

[0022] Finally, the subject of the invention is a nacelle for an aircraft propulsion assembly, comprising at least one blower cover and a thrust reverser as described above.

[0023] Other advantages and features of the invention will appear in the following non-limiting detailed description. Brief description of the drawings

[0024] The following detailed description refers to the accompanying drawings in which:

[0025] [Fig.l] is a schematic half longitudinal section view of a propulsion assembly, comprising a thrust reverser shown in direct thrust configuration;

[0026] [Fig.2] is a schematic half longitudinal section view of the inverter equipped with the propulsion assembly shown in [Fig.l], according to a preferred embodiment of the invention and with the reverser shown in direct thrust configuration;

[0027] [Fig.2A] is a perspective view of a portion of the inverter shown in [Fig.2];

[0028] [Fig.3] is a half schematic view in longitudinal section of the similar inverter to that of [Fig.2], with the reverser shown in an intermediate configuration between the direct thrust configuration and the thrust reversal configuration;

[0029] [Fig.3A] is a perspective view of a portion of the inverter shown in [Fig.3];

[0030] [Fig.4] is a half schematic view in longitudinal section of the similar inverter to that of [Fig.2], with the reverser shown in thrust reversal configuration;

[0031] [Fig.4A] is a perspective view of a portion of the inverter shown in [Fig.4];

[0032] [Fig.5] is an enlarged perspective view of a portion of the inverter shown in the [Fig.2A] ;

[0033] [Fig.6] is an enlarged perspective view of a deployment rod of the secondary vein sealing membrane, belonging to the inverter shown in the previous figures;

[0034] [Fig.7] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.2], with the inverter being presented in an alternative embodiment;

[0035] [Fig.7A] is a schematic half-view in longitudinal section of the reverser similar to that of [Fig.7], with the reverser shown in an intermediate configuration between the direct thrust configuration, and the thrust reversal configuration;

[0036] [Fig.8] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.3], with the inverter being presented in an alternative embodiment;

[0037] [Fig.9] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.8], with the inverter being presented in an alternative embodiment;

[0038] [Fig. 10] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.2], with the inverter being presented in an alternative embodiment;

[0039] [Fig.10A] is a schematic half-view in longitudinal section of the reverser similar to that of [Fig.10], with the reverser shown in an intermediate configuration between the direct thrust configuration, and the thrust reversal configuration;

[0040] [Fig. 11] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.2], with the inverter being presented in an alternative embodiment;

[0041] [Fig. 11 A] is a half schematic longitudinal sectional view of the reverser similar to that of [Fig. 11], with the reverser shown in the thrust reverser configuration;

[0042] [Fig. 12] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.2], with the inverter being in the form of another preferred embodiment of the invention;

[0043] [Fig.l2A] is a half-sectional schematic view of the reverser similar to that of [Fig. 12], with the reverser shown in the thrust reverser configuration;

[0044] [Fig. 13] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.2], with the inverter being in the form of another preferred embodiment of the invention;

[0045] [Fig.l3A] is a half-sectional schematic view of the reverser similar to that of [Fig. 13], with the reverser shown in an intermediate configuration between the direct thrust configuration and the thrust reversal configuration;

[0046] [Fig. 14] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.2], with the inverter being in the form of another preferred embodiment of the invention;

[0047] [Fig.l4A] is a half-sectional schematic view of the reverser similar to that of [Fig. 14], with the reverser shown in the thrust reverser configuration;

[0048] [Fig. 15] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig.2], with the inverter being in the form of another preferred embodiment of the invention;

[0049] [Fig. 16] is a schematic half-view in longitudinal section of the inverter similar to that of [Fig. 15], with the inverter being in the form of an alternative. Detailed description of embodiments

[0050] [Fig.l] shows an aircraft propulsion unit 1, having a longitudinal central axis A1.

[0051] Subsequently, the terms “upstream” and “downstream” are defined relative to a general direction SI of flow of the gases through the propulsion unit 1, along the axis A1 when the latter generates thrust. These terms “upstream” and “downstream” could respectively be substituted by the terms “front” and “rear”, with the same meaning.

[0052] The propulsion unit 1 comprises a turbomachine 2, a nacelle 3 as well as a mast (not shown), intended to connect the propulsion unit 1 to a wing (not shown) of the aircraft.

[0053] The turbomachine 2 is in this example a double-flow, double-spool turbojet engine 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. The turbojet engine 2 is provided with a fan casing 11 connected to the gas generator by structural arms 12.

[0054] The nacelle 3 comprises a front section forming an air inlet 13, a middle section which comprises two fan cowls 14 surrounding the fan casing 11, and a rear section 15.

[0055] In operation, an air flow 20 enters the propulsion unit 1 through the air inlet 13, passes through the fan 5 and then divides into a primary flow 20A and a secondary flow 20B. The primary flow 20A flows in a primary gas circulation vein 21A passing through the gas generator. The secondary flow 20B flows in a secondary vein 21B surrounding the gas generator. The secondary vein 21B is delimited radially inwards by a fixed internal fairing which envelops the gas generator. In this example, the fixed internal fairing comprises a first section 17 belonging to the middle section 14, and a second section 18 extending rearwardly from the first section 17, so as to form a part of the rear section 15. This second section 18 is an integral part of a fixed structure of a thrust reverser which will be described below. This same section will subsequently be called the radially internal delimiting wall 18 of the secondary vein 21B.

[0056] Radially outwardly, the secondary vein 21B is delimited by the fan casing 11, and, in the configuration of [Fig.l], by one or more movable reverser cowls 33 forming a part of the rear section 15 of the nacelle 3, and which will be described later. More precisely, between the fan casing 11 and the reverser cowls 33, there is provided an outer shroud 40 of an intermediate casing 42, the latter comprising the aforementioned structural arms 12, the radially outer end of which is fixed to this shroud 40. The latter therefore also participates in delimiting the secondary vein 21B radially outwardly, by being located in the downstream axial extension of the fan casing 11.

[0057] The nacelle 3 therefore comprises a thrust reverser 30 centered on the axis A1 and comprising on the one hand a fixed structure 31 secured to the fan casing 11, and on the other hand a structure 29 movable relative to the fixed structure 31. The fixed structure 31 comprises for example a front frame 46 which connects it fixedly to the fan casing 11, preferably via a knife-edge flange assembly located downstream of the outer shroud 11. This front frame 46 contains a profiled aerodynamic part called a deflection edge 46B, which guides the flow in an inverted jet.

[0058] Here, the fixed structure 31 also comprises a plurality of deflection grids 32 arranged adjacent to each other around the axis A1, in a circumferential direction of the inverter 30 and the propulsion assembly 1. These grids 32 thus form flow deflection members to generate the counter-thrust. In this regard, it is noted that this flow reversal function can alternatively or simultaneously be carried out using a flexible structure, of the membrane / textile type, as will be described later for other preferred embodiments of the invention.

[0059] Furthermore, the mobile structure 29 comprises the aforementioned mobile reverser cowls 33, for example two cowls 33 each extending over an angular amplitude of approximately 180°. This configuration with two cowls 33 is particularly well suited in the case of a nacelle design in which the cowls / walls 18 are also mounted articulated, the reverser 30 then having a so-called “D-shaped” architecture, known as “D-Duct”. In this architecture, the cowls 18, 33 are connected so as to open / close simultaneously during maintenance operations on the engine. However, other architectures are possible, such as for example a so-called “C-shaped” architecture, known as the Anglo-Saxon name “C-Duct”, or even a so-called “O-shaped” architecture, known under the Anglo-Saxon name “O-Duct”.

[0060] Each movable reverser cowl 33 comprises a radially external wall 50, forming an external aerodynamic surface of the reverser and the nacelle, this surface being matched by the external air. Each cowl 33 also comprises a radially internal wall 52 participating in the delimitation of the secondary vein 21B radially towards the outside. This wall 52 is located in the downstream continuity of the external shell 40 of the intermediate casing. The two walls 50, 52 define a cavity 54 open axially towards the front, at the upstream end of the reverser cowl 33.

[0061] [Fig.l] shows the reverser 30 in a direct forward thrust configuration, called "direct jet", and corresponding to a standard flight configuration. In this configuration, the cowls 33 of the mobile structure 29 are in a closed position, called the advanced thrust or "direct jet" position, in which these reverser cowls 33 are supported on the fixed structure 31, in particular on the deflection edge 46B forming an integral part of the latter. Indeed, in the direct thrust configuration, the upstream end 52a of the radially internal wall 52 of each cowl 33 is in axial support against the deflection edge 46B, thus isolating the cavity 54 from the secondary flow path.

[0062] The movable cowl 33 is held in the forward direct thrust position by means for locking this cowl onto the fixed structure 31 of the reverser. These controlled locking means (not shown) are conventional, so they will not be described further. As an indicative example, active locks may be implemented capable of unlocking under load to counter the compressive force of a joint between the movable structure and the deflection edge. This type of lock may in fact overcompress the joint, so that unlocking can then be controlled.

[0063] The mobile structure 29 is thus movable in translation relative to the fixed structure 31 along the axis A1 of the reverser, between the forward direct thrust position shown in [Fig.l], and a retracted thrust reversal position which will be described later. In the forward direct thrust position of the mobile structure 29, the deflection grids 32 are arranged in the cavity 54 of the reverser cowls 33, being isolated from the secondary vein 21B by the radially internal wall 52 of these sliding reverser cowls 29. This wall 52, forming the external wall of the secondary vein, is also called an acoustic internal panel.

[0064] This direct thrust configuration is also shown in Figures 2 and 2A, while the rearward thrust reversal position of the mobile structure 29 is shown in Figures 4 and 4A. Figures 3 and 3A show the mobile structure in an intermediate position, between the forward direct thrust position, and the rearward thrust reversal position.

[0065] In [Fig. 4], it is shown that the internal acoustic panel 52 set back from the reverser cowls reveals upstream a passage opening 56 of the secondary vein 21B towards the deflection grilles 32. The opening 56 is therefore also delimited upstream by the deflection edge 46B, which flares radially outwards going towards the rear, to channel an air flow intended to pass through the grilles 32 when the mobile system is in this retracted thrust reversal position. In other words, the deflection edge 46B gradually moves away from the axis A1 going from the front to the rear, to guide / deflect the air towards the grilles 32 in the thrust reversal configuration. Downstream, the passage opening 56 is delimited in particular by the upstream end 52a of the radially internal wall 52.

[0066] In order to divert at least a portion of the secondary flow 20B toward the passage opening 56 defined axially between the deviation edge 46B and the upstream end 52a of the radially inner wall 52 of each cover 33, the inverter 30 comprises one or more sealing membranes 58. Subsequently, an embodiment will be described in which a single membrane 58 is associated with each inverter cover 33 while having an identical or similar angular amplitude, but it remains conceivable to provide several circumferentially adjacent membranes associated with each cover 33. Similarly, only the cooperation between a membrane 58 and its associated cover 33 will be described below, it being understood that this cooperation is identical or similar for all the covers of the inverter 33.It is however noted that in addition to the possibility of providing several membranes 58, one or more rigid, more conventional, sealing flaps could be provided in association with this / these membranes, for example alternating in the circumferential direction.

[0067] The membrane 58 may be made of a material known to those skilled in the art for this type of application. For example, it may be a non-impregnated fabric, for example aramid fibers. The membrane 58 may also be made using a composite material whose matrix is ​​particularly flexible, for example aliphatic polyurethane, which allows use under different temperature conditions, in particular lower temperatures in the case of an aliphatic polyurethane membrane than in the case of a silicone membrane. The matrix gives a low bending recovery capacity and the behavior of the structure obtained is indeed that of a membrane. One of the major properties of this membrane 58 is to be able to bend in a perfectly reversible manner (elastic or by fiber sliding) with a very small radius of curvature relative to its surface, and to have a very small thickness, for example of the order of 0.1 to 3 mm.For information, it is observed that this membrane 58 behaves like a sail of . boat or a parachute / flying wing when pressurized.

[0068] It is recalled that in a conventional grid inverter, the mobile structure slides relative to the fixed structure by means of a rail / slide system which guides the mobile structure from front to rear during the opening phase of the inverter, and from rear to front during the closing phase. A rearward force applied to the mobile structure of the inverter therefore causes it to move backward, relative to the fixed structure. This force is usually generated by conventional actuators such as jacks or ball screws.

[0069] Still with reference to Figures 1 to 4A representing a preferred embodiment of the invention, the membrane 58 has two opposite ends, namely a first end 58a connecting to one or more deployment members 62, near a rear frame 60 supporting the grids 32, as well as a second end 58b also connecting to the deployment members 62, and intended to be located near the wall 18 in the thrust reversal configuration. In this regard, it is noted that the membrane 58 can be fixed to each deployment member 62 only at its two ends 58a, 58b, or else be fixed to this member 62 in a punctual or continuous manner along the entire length of the membrane. Alternatively, the first end 58a of the membrane 58 could be connected to the rear frame 60 supporting the grids 32, without departing from the scope of the invention.This support is annular, or in the form of an annular section connecting in effect the rear end of several adjacent grids.

[0070] In this preferred embodiment, the deployment elements 62, arranged at least partly in the secondary vein 21B in the thrust reversal configuration, take the form of connecting rods, here simple connecting rods of preferably straight shape. As mentioned previously, the connecting rods 62 are circumferentially spaced from each other within the secondary vein 21B in the thrust reversal configuration, and their number can for example vary from two to ten in association with the same membrane 58.

[0071] One of the features of the invention lies in the fact that when the movable structure 29 occupies its advanced direct thrust position shown in FIGS. 2 and 2A, each connecting rod 62 is at least partly, and preferably entirely, housed in the cavity 54 of the movable cover 33. No drag is thus generated by the connecting rods 62 in direct jet configuration, which improves the performance of the propulsion assembly.

[0072] Each connecting rod 62 comprises a first end 62a connected to the second end of the membrane 58b. Its second end 62b, opposite the first, is pivotally mounted on the fixed structure of the inverter, preferably on the rear frame 60 for supporting the grilles 32, along a pivot axis of tangential or substantially tangential orientation. ​

[0073] As can be seen in Figures 1, 2 and 2A, when the mobile structure 29 occupies its forward direct thrust position, at least a portion of the closure membrane 58, and preferably the whole of it, is arranged radially between the deflection grids 32 and the radially internal wall 52 of the reverser cover 33, in the cavity 54. The latter is closed by the upstream end 52a of the wall 52 pressing against the deflection edge 46B, so that no portion of the membrane is exposed to the secondary flow in the direct thrust configuration, nor are the connecting rods 62.

[0074] It is also noted that in this advanced direct thrust position, each connecting rod 62 has an axial or substantially axial orientation, a slight radial offset being able to be observed between the two connecting rod ends 62a, 62b, the first end 62a located furthest upstream then being slightly closer to the axis A1 than the second end 62b located downstream.

[0075] As is apparent from the following, the reverser is designed so that during a movement of the mobile structure 29 from its forward direct thrust position to its retracted thrust reversal position, each connecting rod 62 is extracted from the cavity 54 through an upstream opening 54' of the latter, at the same time as it pivots around its second end 62b to plunge its first end 62a radially inwards.

[0076] When the mobile structure 29 reaches its rearward thrust reversal position, each connecting rod 62 has pivoted about its second end 62b sufficiently so that its first end 62a is located close to the wall 18, and preferably downstream relative to the second end 62b. Each connecting rod 62 is also partly in contact with the upstream end 52a of the radially internal wall 52 of the mobile cowl, therefore corresponding to the acoustic panel. This contact makes it possible to stop the deployment and rotation of the connecting rod 62, driven by the pressure forces which are applied to the membrane 58.

[0077] As can be seen in [Fig.4A], between two directly consecutive connecting rods 62, the membrane 58 can be flat or substantially flat, but it is preferably curved due to the deformation applied upstream by the air flow on this membrane.

[0078] In this configuration, the part of the membrane 58 which is located radially outwards relative to the support zone of the connecting rods 62 on the wall 52, closes off a part of the upstream axial opening 54' of the cavity 54. The other part located radially inwards closes off at least a part of the secondary vein 21B, thereby diverting at least a part of the secondary flow 20B towards the passage opening 56, in the direction of the grids 32.

[0079] Another possibility, not shown, consists of carrying out the radially external attachment of the membrane 58 on the radially external wall 50 of the sliding cover 33.

[0080] To allow the combined extraction and diving kinematics of each connecting rod 62 during the opening of the movable cover 33, it is here preferentially provided that the connecting rod 62 is connected to an upstream end 52a of the radially internal wall 52, by means of at least one connecting member 64, here provided in number of two. Each connecting member 64, visible in [Fig.5], is mounted articulated on the upstream end 52a, preferably along a hinge axis 66 of tangential or substantially tangential orientation. The two hinge axes 66 are here merged.

[0081] Furthermore, each connecting rod 62 is slidably mounted on each of these two connecting members 64, preferably having two portions 68, each in the form of a rail cooperating with its associated connecting member 64. Thus, with its two back-to-back rails 68 as shown in [Fig.6], which preferably share the same central core, the connecting rod 62 can have a section in the form of two opposite Ts, sharing the same central base, and with the two T heads each having two opposite curved ends to ensure the holding of the connecting members 64 in the form of sliders.

[0082] These two mechanical connections allow the connecting rod 62 to follow a combined movement relative to the radially internal wall 52 of the movable cover, corresponding to a translation / sliding along this connecting rod 62, and to a rotation along an axis orthogonal or substantially orthogonal to the axis of the previous movement. This combined movement proves to be perfectly suitable for allowing the desired extraction of the connecting rod 62 from the cavity 54, as well as its pivoting causing the first end of the connecting rod 62a to plunge radially inwards.

[0083] It is noted that this combined movement of the connecting rod 62 takes place automatically and passively when the reverser is opened, in particular thanks to the air pressure which is applied to the membrane 58, and which pushes each connecting rod 62 to deploy according to the desired kinematics. In addition, the combined movement of the connecting rod 62 takes place in the opposite direction, when the reverser is closed, also automatically and passively following the simple movement of the movable cover 33 upstream, the upstream end 52a of which presses on each connecting rod 62.

[0084] To further facilitate the deployment of each connecting rod 62, in particular during an initial phase of opening the reverser, the latter may comprise at least one spring 70 for assisting the movement of the connecting rod 62 in the secondary vein 21B. Such a solution is shown in FIGS. 7 and 7A, in the form of a coil compression spring arranged between the fixed structure of the reverser, for example near the deflection edge 46B, and the connecting rod 62, for example near its first end 62a. Here, the spring 70 is preferably arranged radially or substantially radially.

[0085] In a similar manner, a spring 72 may be provided for damping the end of movement of the connecting rod 62, during a movement of the mobile structure 29 from its forward direct thrust position, to its retracted thrust reversal position. An example is shown in [Fig.8], showing such a coiled traction spring 72 arranged between the fixed structure, preferably the rear support frame 60 or a nearby element, and the connecting rod 62, preferably its second end 62b.

[0086] Another embodiment is shown in [Fig.9], in which the coil compression spring 72 is arranged between the movable structure 29, preferably the external wall 50 of the movable cover, and the connecting rod 62, preferably an extension 76 thereof which extends beyond the articulated connection of this connecting rod on the rear support frame 60.

[0087] The two springs 70, 72 can of course be implemented within the same inverter, to respectively fulfill the two desired functions.

[0088] For the spring 70 for assisting the movement of the connecting rod 62 in the secondary vein 21B, a leaf spring can also be considered, as shown in FIGS. 10 and 10A. The leaf spring 70 is here fixed to the radially external wall 50 of the movable reverser cover 33, being arranged inside the cavity 54. It presses on a radially external face of the connecting rod 62, to ensure its deployment.

[0089] In this last example, the connecting rod 62 is no longer straight but curved, here in the general shape of a C, particularly open. The hollow of the C is oriented radially inwards in the direct thrust configuration, to facilitate the output kinematics of the connecting rod 62, during its deployment in the secondary vein 21B, outside the cavity 54. This particular shape of the connecting rod 62, as well as its orientation, in fact make it possible to better bypass the deflection edge 46B during the combined output movement of the connecting rod. Of course, this curved shape of the connecting rod 62 can be adopted independently of the implementation or not of the spring(s) 70, 72.

[0090] Other curved shapes are also conceivable for the connecting rod 62, such as the general shape of an S with the upstream hollow oriented radially inwards in the direct thrust configuration, and its downstream hollow oriented radially outwards. This embodiment is shown in Figures 11 and 1 IA. The orientation of the upstream hollow makes it possible to better bypass the deflection edge 46B during the combined output movement of the connecting rod 62, as for the C-shaped connecting rod described previously. In addition, the inverted orientation of the downstream hollow makes it possible, when the connecting rod 62 and the membrane 58 which follows its profile are in the reverse thrust configuration, to orient the air of the secondary flow with a component towards the upstream before it passes through the grids 32, as has been shown diagrammatically by the arrow in [Fig. 1 IA].

[0091] Figures 12 and 12A show another preferred embodiment of the invention, in which the connecting rod 62 has a telescopic character, which allows it to have a reduced bulk when it is stored in the cavity 54. To do this, a system for controlling the telescopic connecting rod 62 is provided, comprising an actuating spring 80 as well as a cable 82 for controlling the deployment of this spring. More precisely, this control system is of passive design, so that it allows automatic deployment of the connecting rod 62 during its extension kinematics, when opening the reverser. Similarly, the control system allows the connecting rod 62 to retract automatically during its reentry kinematics in the cavity 54, when closing the reverser.

[0092] These functions are made possible, for example, by fixing one end of the cable 82 to the spring 80, and by fixing the other end of this cable to the upstream end 52a of the radially inner wall 52 of the movable cover 33 of the inverter, while ensuring that this cable 82 bypasses the second end of the connecting rod 62b.

[0093] Thus, during the opening of the movable cover 33, the end of the cable 82 fixed to the movable cover moves closer to the second end of the connecting rod 62b, which has the effect of relaxing the spring 80, which then forces the sliding part of the connecting rod to deploy, thus increasing the length thereof. During the closing of the movable cover 33, the end of the cable 82 fixed to the movable cover moves away from the second end of the connecting rod 62b, which has the effect of compressing the spring 80, which causes with it the withdrawal of the sliding part of the telescopic connecting rod, thus reducing the length of this connecting rod which re-enters the cavity 54 of the movable reverser cover.

[0094] Another preferred embodiment of the invention is shown in Figures 13 and 13A. It implements another guide system for tilting the connecting rod 62 into the secondary vein 21B, when the reverser is opened. To do this, this guide system for the connecting rod 62 comprises a radially internal guide member 86a, such as a pad or a roller permanently bearing on a radially internal surface of this connecting rod. Preferably, the guide member 86a, located in the cavity 54, is mounted on the radially internal wall 52 of the mobile reverser cover, on or near its upstream end 52a. Similarly, the guide system for the connecting rod 62 comprises another radially external guide member 86b, such as a pad or a roller permanently bearing on a radially external surface of this connecting rod.Preferably, the guide member 86b, also located in the cavity 54, is mounted on the radially external wall 50 of the movable reverser cover, on or near its upstream end 50a.

[0095] The radially internal guide member 86a is not only radially offset from the radially external guide member 86b, but it is also arranged upstream of the latter. Consequently, during the entire movement of the movable cover 33 during from its opening, the connecting rod 62 pivots around its end 62b, while being forced to remain in contact with each of the two members 86a, 86b, due to its drive by the sealing membrane, itself subjected to the air pressure in the secondary vein. Thus, as the movable cover 33 moves back, the first end of the connecting rod 62a gradually plunges into the secondary vein 21B, with the kinematics of this connecting rod controlled by the two members 86a, 86b. The opposite phenomenon is observed when the reverser closes, during which the connecting rod 62 gradually re-enters the cavity 54.

[0096] Figures 14 and 14A show another preferred embodiment of the invention, in which the flow deflection member 32 is no longer a grid, but it comprises a membrane that can be deployed using connecting rods 88. The flow reorientation membrane 32 is then preferably of the same type as that of the closure membrane 58. It is also stored in the cavity 54 in a direct thrust configuration, and the connecting rods 88 which carry this membrane 32 have a rear end articulated on the fixed structure, for example on the rear support frame 60 on which the second connecting rod ends 62b are also articulated.

[0097] The pivoting of the connecting rods 88 is observed as the movable cover 33 moves rearwardly, and their deployment can be stopped by stop means 90, arranged for example on the rear support frame 60, as has been shown diagrammatically in [Fig. 14A]. Another possibility lies in the fixing of the stop means 90 on the radially external wall 50 of the movable reverser cover 33, or even on an extension of the connecting rods 62 located two by two in the same planes with these connecting rods 88, without departing from the scope of the invention.

[0098] Figures 15 and 16 show yet another preferred embodiment of the invention, in which the reverser comprises stop means 92 limiting the deployment of the connecting rods 62. These stop means 92 are preferably arranged on the radially external wall 50 of the movable reverser cover 33, for example on or near the upstream end 50a. They are provided to preferably come into contact with an extension 76 of each connecting rod 62, which extends beyond the articulated connection of this connecting rod on the rear support frame 60.

[0099] Consequently, in the thrust reversal position as shown in [Fig. 15], on either side of its articulated connection, the connecting rod 62 is in contact with the two upstream ends 50a, 52a of the movable cowl 33. The axial forces applied by the connecting rod 62 at these two ends 50a, 52a are in opposite directions, and can thus advantageously balance each other, thereby limiting the stress on the actuators of the reverser.

[0100] According to an alternative form shown in [Fig. 16], it could even be envisaged that the connecting rod 62 is no longer in contact with the upstream end 52a of the wall radially internal 52 of the cover 33, but simply in contact with the upstream end 50a of the radially external wall 50, by means of its extension 76. Moreover, it is noted that in this alternative form, in the thrust reversal configuration, the first connecting rod end 62a remains upstream of the second articulated connecting rod end 62b.

[0101] Various modifications may be made by those skilled in the art to the invention which has just been described, solely by way of non-limiting examples, and the scope of which is defined by the appended claims. For example, the thrust reverser 30 may alternatively have a “C” or “O” architecture. Furthermore, the membranes specific to the invention may coexist with conventional grids within the reverser. Furthermore, all the features disclosed above, in the various preferred embodiments and their alternatives, are combinable with each other. Moreover, it is noted that in all the figures which have been described above, the elements which bear the same numerical references correspond to identical or similar elements.

Claims

Claims

1. Thrust reverser (30) for an aircraft propulsion unit, the reverser comprising a fixed structure (31) equipped with a radially internal delimiting wall (18) of a secondary vein (21B) of the propulsion unit intended to be crossed by a secondary flow (20B), the reverser also comprising a movable structure (29) comprising at least one reverser cowl (33) having a cavity (54) open upstream and delimited between a radially external wall (50) and a radially internal wall (52) of the reverser cowl (33), the movable structure being movable in translation relative to the fixed structure along a longitudinal central axis (Al) of the reverser,between an advanced direct thrust position and a retracted thrust reversal position in which the retracted radially internal wall (52) of the reverser cowl reveals upstream a passage opening (56) from the secondary vein (21B) to a flow deflection member (32), the reverser also comprising a membrane (58) for closing the secondary vein (21B), as well as a membrane deployment member (62) connected to this membrane (58), and designed to be arranged at least partly in the secondary vein (21B) when the mobile structure occupies its retracted thrust reversal position, characterized in that when the mobile structure (29) occupies its advanced direct thrust position, the membrane deployment member (62) is at least partly housed in the cavity (54) of the mobile reverser cowl (33).

2. Inverter according to claim 1, characterized in that it is designed so that during a movement of the mobile structure (29) from its forward direct thrust position to its retracted thrust reversal position, the membrane deployment member (62) is extracted from the cavity (54) through an upstream opening (54') of this cavity.

3. Inverter according to claim 1 or 2, characterized in that the membrane deployment member (62) is a connecting rod, preferably taken from: - a straight connecting rod; - a curved connecting rod, for example in the general shape of a C or an S; - a telescopic connecting rod, preferably associated with a control system comprising an actuating spring (80) and a cable (82) spring deployment control (80).

4. Inverter according to any one of the preceding claims, characterized in that the membrane deployment member (62) comprises an end (62b) mounted in an articulated manner on the fixed structure (31) of the inverter, preferably on a rear frame (60) supporting the flow deflection member (32).

5. Inverter according to any one of the preceding claims, characterized in that the membrane deployment member (62) is connected to an upstream end (52a) of the radially internal wall (52), by means of at least one connecting member (64) mounted articulated on the upstream end (52a), preferably along a hinge axis (66) of tangential or substantially tangential orientation, the deployment member (62) being slidably mounted on this connecting member (64), preferably having a rail-shaped portion (68) cooperating with the connecting member (64).

6. Inverter according to any one of claims 1 to 4, characterized in that it comprises a system for guiding the connecting rod deployment member, comprising a radially internal guide member (86a), preferably mounted on the radially internal wall (52) of the movable inverter cover, as well as a radially external guide member (86b), preferably mounted on the radially external wall (50) of the movable inverter cover, the radially internal guide member (86a) being preferably arranged upstream of the radially external guide member (86b).

7. Reverser according to any one of the preceding claims, characterized in that it comprises at least one spring (70) for assisting the movement of the membrane deployment member (62) in the vein (21B), and / or in that it comprises at least one spring (72) for damping the end of movement of the deployment member (62), during a movement of the mobile structure (29) from its forward direct thrust position to its retracted thrust reversal position.

8. Inverter according to any one of the preceding claims, characterized in that the flow deflection member (32) comprises a membrane deployable using connecting rods (88), and in that the inverter comprises stop means (90) for said connecting rods (88), preferably arranged on the radially external wall (50) of the movable inverter cover (33).

9. An inverter according to any preceding claim, ca- characterized in that the inverter comprises stop means (92) for the membrane deployment member (62), preferably arranged on the radially external wall (50) of the movable inverter cover (33).

10. Nacelle (3) for an aircraft propulsion unit, comprising at least one fan cowl (14), as well as a thrust reverser (30) according to any one of the preceding claims.