The forward frame and deflection grille of the thrust reverser in the aircraft cabin

Abstract

The present invention relates to an assembly (601) comprising a forward frame (602) of a thrust reverser structure for an aircraft nacelle and at least one blade cascade (603). The assembly is characterized in that, when the blade cascade is fixed to the frame, the axial distance (L) separating the first blade (605) upstream of the blade cascade from the covered area (606) located between the extension of the blade cascade and the forward frame is greater than or equal to twice the average height (h) of the blade cascade.

Description

Technical Field

[0001] This invention relates to the field of aircraft turbojet engine nacelles. In particular, it relates to thrust reversing systems equipped with such nacelles, and more specifically, to assemblies comprising a front frame and a plurality of deflection grilles for such thrust reversing systems. Background Technology

[0002] Prior art includes, in particular, documents US-A-4 177 639, RU-C1-2 145 672 and EP-A1-1 176302.

[0003] Thrust reversing systems, or thrust reversers, are now widely used in aircraft nacelles, particularly those housing dual-flow turbojet engines. In a known manner, such turbojet engines generate a hot airflow (known as the main flow) from the combustion chamber via the blades of a rotating fan, and a cool airflow (known as the secondary flow) that flows outside the turbojet engine through an annular channel formed between the turbojet engine's cowling and the inner wall of the nacelle. Both airflows are then expelled from the turbojet engine through the rear of the nacelle, thus generating thrust.

[0004] In this configuration, the thrust reverser functions to enhance the aircraft's braking ability on the ground during the landing phase by redirecting at least a portion of the thrust generated by the turbojet engine forward. Specifically, when the thrust reverser operates, it blocks the annular channel of the cold airflow (i.e., the secondary flow) and redirects that flow towards the front of the cabin, thereby generating reverse thrust.

[0005] The method used to redirect the cold airflow varies depending on the type of thrust reverser. However, in all cases, the thrust reverser configuration includes movable covers that can be displaced between an extended position (also known as the thrust reversing position) and a retracted position (also known as the direct injection position). In the extended position, these covers open a passage in the nacelle for the redirected flow, and in the retracted position, they close that passage. These covers can thus be used to activate other deflection devices, such as flaps. In this case, the flaps activated by the displacement of the movable covers at least partially obstruct the passage through which the secondary flow passes.

[0006] In addition, in the case of a thrust reverser with a deflection grille, the airflow is redirected by the deflection grille.

[0007] Figure 1 A portion of the aircraft cabin 101 is schematically shown, including a thrust reverser 111 in a thrust-reversing position according to the prior art. The flow of air is indicated by arrow 109, and the terms upstream and downstream are used hereinafter with reference to this flow direction.

[0008] The reverser 101 includes at least one cover 102 movable relative to a fixed structure 103 of the internal duct (referred to as the "Inner Fixed Structure (IFS)"). The cover 102 has an outer wall 104 and an inner wall 105 that defines the outer wall of an annular passage 106 through which the secondary flow passes at the direct injection position of the turbojet engine (not shown). The reverser also includes at least one flap 107 hinged to the movable cover 102. At least one actuator (e.g., a lifter (not shown)) slides the movable cover 102 and causes one or more flaps 107 to close the annular passage 106. The flaps 107 deflect at least a portion of the secondary flow away from the annular passage 106 toward a deflection grid 110, thereby generating reverse thrust.

[0009] Therefore, the redirection of the secondary flow can be achieved by the deflection grilles 110, depending on whether the translation of the movable cover along axis X (around which the nacelle extends) covers or uncovers these deflection grilles. The deflection grilles 110 are also arranged adjacent to each other in the annular region surrounding the annular channel 106 and include a series of blades 115 extending from upstream to downstream.

[0010] Region 112 corresponds to the connection area between the fixed structure of the thrust reverser 111, referred to as the front frame 113, the deflection grille 110, and the deflection edge 114. This connection area is... Figure 2 It is shown in more detail below.

[0011] In the known prior art, the deflection grille 110 is attached to the casing of the turbojet engine via the front frame 113. An element referred to as the deflection edge 114 is also attached to the front frame, enabling the formation of aerodynamic lines and the guidance of airflow toward the deflection grille 110, as indicated by arrow 201.

[0012] In the example shown, the downstream segment 203 of the front frame 113 is used to attach both the deflection grille 110 and the deflection edge 114. Furthermore, the deflection edge 114 includes a bend 205 that forms a cavity 204 in which the attachment device (not shown) is housed. Thus, the deflection grille, the front frame, and the deflection edge are attached together by a common attachment device located at the height of the cavity and near the first upstream blade 202 of the deflection grille, upstream of the blade.

[0013] Therefore, as Figure 2As shown, in the known prior art, the attachment of the various components constituting the thrust reverser relies particularly on the presence of an axial over-length of the front frame compared to the length 206. Here, the term "over-length" is used in comparison to a length less than or equal to the threshold 206, which in particular allows for a simplified front frame manufacturing process by making the front frame dimensions compatible with manufacturing through simple machining of a single block of material. In other words, an over-length front frame requires a more complex and costly manufacturing process. Summary of the Invention

[0014] This invention proposes a solution that limits the size of the front frame attached to the deflection grille, thereby enabling the front frame to be manufactured using a simple and economical method. Furthermore, this invention maintains the aerodynamic performance of the thrust reverser at least equivalent to that of prior art reversers.

[0015] Therefore, according to a first aspect, the present invention relates to an assembly comprising a front frame of a thrust reverser structure for an aircraft nacelle and at least one deflection grille, the assembly being annular and extending about an axis, the deflection grille comprising an upstream grille extension that extends radially and / or axially relative to the axis of the assembly, such that the grille can be attached to the front frame, the assembly being characterized in that, when the deflection grille is attached to the frame, the axial distance separating a first upstream blade of the deflection grille from an overlapping area located between the grille extension and the front frame is greater than or equal to one time the average height of the deflection grille.

[0016] The components according to the invention may include one or more of the following features, which are employed individually or in combination with each other:

[0017] The component also includes a deflection edge attached to the front frame and configured to guide the gas flow toward the deflection grille.

[0018] - The deflection edge includes a bend that is adapted such that when the deflection edge is attached to the front frame, the end of the deflection edge overlaps with the front frame.

[0019] - The deflection grille is attached to the front frame via an attachment device located in the overlapping area between the grille extension and the front frame.

[0020] - The deflection grille is attached to the deflection edge via a first attachment device, and the deflection edge is attached to the front frame via a second attachment device, different from the first attachment device, at a height at the end of the deflection edge closest to the deflection grille.

[0021] - The deflection grille, deflection edges, and front frame are attached to each other by a common attachment device located in the overlapping area between the grille extension and the front frame.

[0022] - The front frame also includes corner pieces adapted to allow deflection edges and deflection grilles to be attached to the front frame.

[0023] - The corner piece is attached to the deflection edge via a first attachment device, and wherein the deflection grille is attached to the front frame via a second attachment device.

[0024] - The grille extension of the deflection grille also includes a profile adapted to allow the deflection grille to be attached to the deflection edge and the front frame, and when the deflection grille is attached to the front frame, the axial distance between the first upstream blade of the deflection grille and the overlapping area between the profile and the front frame is greater than or equal to one time the average height of the deflection grille.

[0025] - The profile is attached to the deflection edge via a first attachment device and to the front frame via a second attachment device.

[0026] - The attachment devices used to attach deflector grilles and / or deflector edges and / or corner pieces to the front frame are countersunk and lock nut type or screw and lock nut type. Attached Figure Description

[0027] The invention will be better understood from the following description, which is given by way of non-limiting example and with reference to the accompanying drawings, and other details, features, and advantages of the invention will become clearer, as illustrated in the drawings:

[0028] [ Figure 1 ] Figure 1 This is a schematic diagram of the longitudinal cross-section of a thrust reverser in the thrust reversal position based on existing technology.

[0029] [ Figure 2 ] Figure 2 This is a longitudinal cross-sectional schematic diagram of the connection area between the front frame, deflection grille, and deflection edge of a thrust reverser based on existing technology.

[0030] [ Figure 3 ] Figure 3 This is a longitudinal cross-sectional schematic diagram of the connection area between the front frame, deflection grid, and deflection edge of the thrust reverser according to a first embodiment of the present invention.

[0031] [ Figure 4 ] Figure 4 This is a longitudinal cross-sectional schematic diagram illustrating an attachment device for attaching a deflection grille and / or deflection edge to the front frame of a thrust reverser according to an embodiment of the present invention.

[0032] [ Figure 5 ] Figure 5 This is a schematic perspective view illustrating the manufacturing of a front frame according to the invention by machining a veneer of a given material;

[0033] [ Figure 6 ] Figure 6 This is a longitudinal cross-sectional schematic diagram of the connection area between the front frame, deflection grid, and deflection edge of the thrust reverser according to a second embodiment of the present invention.

[0034] [ Figure 7 ] Figure 7 This is a longitudinal cross-sectional schematic diagram of the connection area between the front frame, deflection grid, and deflection edge of the thrust reverser according to a third embodiment of the present invention.

[0035] [ Figure 8 ] Figure 8 This is a longitudinal cross-sectional schematic diagram of the connection area between the front frame, deflection grille, and deflection edge of the thrust reverser according to the fourth embodiment of the present invention; and,

[0036] [ Figure 9 ] Figure 9 This is a longitudinal cross-sectional schematic diagram of the connection area between the front frame, deflection grille, and deflection edge of the thrust reverser according to the fifth embodiment of the present invention.

[0037] Elements that have the same function in different embodiments have the same reference numerals in the drawings. Detailed Implementation

[0038] Reference Figure 3 The first embodiment of the present invention will now be described. Components according to the invention can be integrated into systems including thrust reversers (e.g., referred to above). Figure 1 The thrust reverser described is used in the cabin of any type of aircraft.

[0039] Component 601 includes a forward frame 602 of the thrust reverser structure of the aircraft nacelle and at least one deflection grille 603. Component 601 is annular and extends about axis X. Therefore, the terms axial and radial used below are understood relative to this axis. Those skilled in the art will understand that, in certain embodiments, such annular component may include deflection grilles not arranged in consecutive 360-degree corner sectors. For example, there may be space between two adjacent deflection grilles, or some corner sectors may not include grilles.

[0040] The deflector grille 603 includes a grille extension 604 upstream in the gas flow direction. The grille extension 604 corresponds to an axially extending elongated section of the deflector grille 603. This extension is designed to allow the grille to be attached to the front frame. Furthermore, the extension allows the position of the first upstream blade 605 to remain constant relative to the assembly within the duct in which the flow passes (in the thrust-reversed position), where the front frame will extend further downstream axially. In other words, the upstream extension of the grille compensates for the shortening of the front frame compared to prior art front frames.

[0041] Specifically, such as in Figure 6 As can be seen more clearly in all embodiments of the invention, when the deflection grille 603 is attached to the front frame, the axial distance L between the first upstream blade 605 of the deflection grille and the overlapping area 606 located between the grille extension and the front frame is greater than or equal to one times the average height h of the deflection grille. Specifically, the axial distance L is defined, on the one hand, upstream by the most downstream axial station of the front frame, and on the other hand, downstream by the most upstream axial station of the root of the first channel of the deflection grille. The average height h is defined as the radial distance between the lower surface 603a and the upper surface 603b of the grille (by...). Figure 6 The arrows in the diagram indicate the average value across the entire surface of the grating. Furthermore, the height h of the grating can vary across the surface of the grating, and the average value can be measured in the axial and / or circumferential directions of the grating.

[0042] The term "overlapping area" refers to the area where the elements involved (in this case, the grille extension and the front frame) directly overlap or overlap through a third element.

[0043] Those skilled in the art will understand that, in representing different embodiments of components according to the present invention Figure 3 , Figure 6 , Figure 7 , Figure 8 as well as Figure 9 In the diagram, the attachment devices of the different elements of the assembly are not shown, but the positions of the attachment devices are symbolically indicated by solid lines passing through the elements attached to each other.

[0044] also, Figure 4 A non-limiting example of an attachment device is shown for attaching a deflector grille and / or deflector edges and / or corner pieces (as described later) to a front frame. In the figures, attachment device 401 shown on the left side is of the countersunk and lock nut type, while attachment device 402 shown on the right side is of the screw and lock nut type 402. Advantageously, attachment device 402 enables the transfer of forces borne by the deflector edges to the front frame.

[0045] In reference Figure 3In the example corresponding to the described embodiment, the overlapping area is the area where the grille extension 604 is connected to the segment 609 of the deflection edge 607, which itself is connected to the segment 610 of the front frame.

[0046] In fact, in certain embodiments of the component, the component also includes a deflection edge attached to the front frame and configured to guide gas flow toward the deflection grille. Figure 3 In the example shown, at the thrust reversal position, the flow follows the trajectory indicated by arrow 611.

[0047] Furthermore, in the downstream axially extending section of the deflection edge 607 of the front frame, the deflection edge includes a bend 608 (also referred to as a return section), which is adapted to overlap the end (segment) 609 of the deflection edge with a segment 610 of the front frame. Advantageously, from the perspective of flow through the assembly, the downstream axially extending section of the deflection edge of the front frame helps to improve the aerodynamic continuity of the assembly.

[0048] Finally, the grille extension allows the grille to be attached to a shorter front frame than in the prior art. Therefore, as in... Figure 5 As shown, the corner sectors of the front frame (intended to be assembled with other sectors to form a complete frame) can be made into a single machined part, for example, from a single piece (plate) of a given material. The given material is, for example, aluminum 7040. In particular, it is no longer necessary to assemble two separate elements in the axial direction to manufacture the corner sectors of this front frame.

[0049] exist Figure 3 In the example shown, the deflection grille, deflection edge, and front frame are attached together by a common attachment device located in the overlapping area between the grille extension and the front frame. Figure 6 , Figure 7 , Figure 8 as well as Figure 9 Variations are shown where different components are attached to each other in different ways. Figure 6 and Figure 7 An embodiment of an assembly including a front frame, a deflection grille, and a deflection edge is shown, wherein the deflection grille is directly attached to the front frame via a first attachment means located in the overlapping area between the grille extension and the front frame, and the deflection edge is attached to the front frame at the height of the end of the deflection edge closest to the deflection grille via a second attachment means different from the first attachment means.

[0050] In addition, Figure 6 In the illustrated embodiment, the grille extension extends axially upstream of the grille, while... Figure 7In the illustrated embodiment, the grille extension extends radially, and therefore, the section of the front frame attached to the grille extension also extends radially. Those skilled in the art will know how to adjust these specific arrangements for particular manufacturing, robustness, and / or overall dimensional constraints.

[0051] It should be noted that in various embodiments of this component, the bend 608 of the deflection edge 607 can be larger or smaller, such that the end 609 of the deflection edge forms a return portion upstream or extends radially in the section of the deflection edge intended to be attached to the front frame. Furthermore, in reference to... Figure 3 In the described embodiment, the bend 608 allows the end portion 609 to extend axially upstream and interact with the grille extension and the front frame to attach the three elements together. Conversely, in reference... Figure 6 , Figure 7 , Figure 8 as well as Figure 9 In the described embodiment, the bend 608 means that the end 609 of the deflection edge extends radially to allow attachment to the inner radial extension of the front frame (i.e., in...). Figure 6 and Figure 7 (in the middle) or the internal radial extension of the assembly component (i.e., in the middle) Figure 8 and Figure 9 Similarly, those skilled in the art will know how to adjust the shape of the deflection edge and the shape of the front frame segment facing the deflection edge in response to, for example, specific manufacturing and / or aerodynamic constraints.

[0052] In reference Figure 8 In the illustrated embodiment, the front frame also includes a corner piece adapted to allow the deflection edges and deflection grille to be attached to the front frame. This corner piece itself can be attached to the rest of the front frame via a common attachment device, which may be the same as or different from a common attachment device used for attaching the deflection grille.

[0053] exist Figure 8 In the example shown, corner piece 801 is attached to the deflection edge via a first attachment device, and the deflection grille is attached to the front frame via a second attachment device. Therefore, in this particular case, the attachment of the deflection grille to the front frame is achieved at the height of the overlapping area 606 between the corner piece 801, portion 602, and grille extension 604 of the front frame.

[0054] Advantageously, using such corner pieces can reduce the axial dimension of the front frame, thereby simplifying the manufacturing of the front frame by machining individual material blocks, and can also enable the use of deflection grilles that do not require any modifications compared to existing deflection grilles.

[0055] In reference Figure 9In the illustrated embodiment, the grille extension of the deflection grille further includes a profile adapted to allow the deflection grille to be attached to the deflection edge and the front frame.

[0056] In the example shown, profile 901 is attached to the deflection edge via a first attachment device and to the front frame via a second attachment device. In other words, the deflection grille 603 is not directly attached to the portion 602 of the front frame, but rather attached to the portion 602 of the front frame via profile 901. Therefore, in this particular case, the attachment of the deflection grille to the front frame is achieved at the height of the overlapping area 606 between profile 901 and the front frame.

[0057] Advantageously, using this profile can reduce the axial dimension of the front frame, thereby simplifying the manufacturing of the front frame by machining individual material blocks, and can also enable the use of a deflection grille that requires no modification compared to existing deflection grilles.

Claims

1. An assembly (601) comprising a front frame (602) of a thrust reverser structure for an aircraft nacelle and at least one deflection grille (603), the assembly being annular and extending about an axis (X), the deflection grille comprising an upstream grille extension (604) extending radially and / or axially relative to the axis (X) of the assembly, the grille being designed to allow the grille to be attached to the front frame, the assembly being characterized in that, when the deflection grille is attached to the front frame, the axial distance (L) separating a first upstream blade (605) of the deflection grille from an overlapping area (606) located between the grille extension and the front frame is greater than or equal to one times the average height (h) of the deflection grille. The component also includes a deflection edge (607) attached to the front frame and configured to guide gas flow toward the deflection grille, and The front frame also includes a corner piece (801) adapted to allow the deflection edge (607) and the deflection grille (603) to be attached to the front frame (602), and when the deflection grille (603) is attached to the front frame (602), the axial distance (L) between the first upstream blade (605) of the deflection grille and the overlapping area (606) between the grille extension and the corner piece is greater than or equal to twice the average height (h) of the deflection grille.

2. The component (601) according to claim 1, wherein, The deflection edge (607) includes a bend (608) that is adapted such that when the deflection edge is attached to the front frame, the end (609) of the deflection edge overlaps with the front frame (602).

3. The component (601) according to claim 1 or 2, wherein, The deflection grille (603) is attached to the front frame (602) by attachment devices (401, 402) located in the overlapping area (606) between the grille extension and the front frame.

4. The component (601) according to claim 1 or 2, wherein, The corner piece (801) is attached to the deflection edge (607) via a first attachment device, and wherein the deflection grille (603) is attached to the front frame (602) via a second attachment device.

5. A thrust reverser for an aircraft cabin, the thrust reverser comprising the components according to any one of claims 1 to 4.

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