US20140086678A1

US20140086678A1 - Assembly for an aircraft nacelle

Info

Publication number: US20140086678A1
Application number: US14/093,761
Authority: US
Inventors: Xavier Cazuc; Christophe Thorel; John Moutier
Original assignee: Aircelle SA
Current assignee: Safran Nacelles SAS
Priority date: 2011-05-30
Filing date: 2013-12-02
Publication date: 2014-03-27
Also published as: CA2837439A1; FR2975970B1; BR112013027790A2; WO2012164197A1; EP2714517A1; CN103582597A; RU2013157084A; FR2975970A1; EP2714517B1

Abstract

An assembly for an aircraft nacelle includes a reinforcing plate and a flange that includes one first portion and one second portion. The first portion of the flange is attached to another flange, and the second portion extends transversely relative to the first portion and is attached onto a panel of the assembly. In particular, the reinforcing plate is attached directly, or optionally indirectly, onto the flange via an intermediate plate attached between the reinforcing plate and the flange. The reinforcing plate has a beveled portion opposite the second portion of the flange.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No. PCT/FR2012/051123, filed on May 21, 2012, which claims the benefit of FR 11/54685, filed on May 30, 2011. The disclosures of the above applications are incorporated herein by reference.

FIELD

The present disclosure relates to an assembly including a flange and a reinforcing plate of that flange, intended for an aircraft nacelle.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
An aircraft turbojet engine nacelle has a structure comprising an air inlet, a metal structure surrounding a fan of the turbojet engine, and a downstream section surrounding the turbojet engine and generally housing a thrust reverser system.
Such an assembly can be used, non-limitingly, in mounting the air inlet and the midsection of the nacelle, as illustrated more particularly in FIG. 1.
The air inlet structure of the nacelle is divided into two zones, i.e. on the one hand an annular air inlet lip with an aerodynamic profile suitable for allowing optimal capture toward the turbojet engine of the air necessary to supply the fan and inner compressors of the turbojet engine, and on the other hand a downstream structure comprising an annular inner shroud and an annular outer cowl radially spaced away from the inner shroud, on which inner shroud the lip is attached and intended to channel the air suitably toward the fan.
Such a shroud is illustrated in FIG. 1 and designated by reference 10. This inner shroud 10 of the air inlet structure is traditionally treated to form a sound attenuation structure 11 for the sound wave.
It may include an air-permeable inner skin, an air-impermeable outer skin and a honeycomb cellular core.
Other alternatives can be considered, such as replacing the cellular core with porous foam or microspheres.
In reference to FIG. 1 as well, the midsection comprises an inner casing 20 surrounding the fan of the turbojet engine (not shown) extending the inner shroud 10 of the air inlet structure on the one hand, and an outer fairing structure (not shown) of the casing extending the outer shroud of the air inlet structure on the other hand.
The inner shroud 10 is intended to be fixed to the fan casing 20 in a junction plane designated by the letter A, using peripheral connecting flanges 30, 40 placed on the downstream end of the inner shroud 10 and the upstream end of the fan casing 20, respectively.
In one form, the connecting flange 30 comprises a first part 31 extending in a radial direction and a second part 32 extending in the longitudinal direction of the turbojet engine, such that the longitudinal section of the flange 30 is L-shaped.
The second connecting part 32 of the flange 30 corresponding to the inner shroud 10 of the air inlet structure is intended to be fixed on said shroud 10.
The flange 30 is generally made by draping pre-impregnated fabrics with autoclave curing, in dry fabrics or with a woven preform with injection of the Resin Transfer Molding type or by infusion.
The connecting flange 30 of the inner shroud 10 may be connected by any known fastening means and/or centering means making it possible to ensure centering of the two structures to be fixed together (not shown in FIG. 1) to the connecting flange 40 of the casing 20 at the junction plane A, through the orifice 35.
Traditionally, a reinforcing plate 33 may be connected on one and/or the other of the flanges, here the flange 30 corresponding to the inner shroud 10.
This reinforcing plate 33 makes it possible to meet the structural strength requirements of the connecting flange 30.
It is suitable for shaping the corresponding flange, and in particular for defining the curve radius of the latter.
It is also suitable for defining the stiffness of the flange 30 over its entire circumference.
It also avoids unfolding of the plies of the flange 30 in the radius when the shroud 10 is subjected to traction forces and damps the strains generated by the tightening of the fastening means.
However, as can be seen in FIG. 2, when the reinforcing plate 33 is attached to the flange 30, it generates a bead 320 in the flange 30, situated at the side of the reinforcing plate 33.
This bead 320 forms an abrupt local thickness variation, typically 0.5 mm, which causes a variation in the fiber level and the orientation of those fibers of the composite material forming the flange 30.
In extreme loading cases, this is detrimental to the mechanical strength of the flange 30.
Furthermore, the stiffness variation between the flange part 30 and the shroud 10 may, in the case of a radial force applied on the flange 30, create a weak spot at the shroud part at the flange 30/shroud 10 transition.

SUMMARY

The present disclosure provides an assembly for an aircraft nacelle, comprising:

- a flange including at least one first part intended to be fixed to another flange and one second part extending transversely relative to the first part and intended to be fixed on a panel of said assembly, and
- a reinforcing plate attached directly on the flange or, optionally, indirectly using an intermediate plate fixed between the reinforcing plate and the flange, said reinforcing plate having a beveled part across from the second part of the flange.

Owing to the present disclosure, a bead is prevented from being created on the second part of the flange, and the physical health of the composite is thereby improved.
Furthermore, this beveled shape allows a less abrupt stiffness transition between the flange and the shroud on which it rests and improves the mechanical strength of the shroud in the junction area with the flange under radial bias.
According to specific forms of the present disclosure, the assembly according to the present disclosure may comprise one or more of the following features, considered alone or in any technically possible combination:

- the beveled part of the reinforcing plate is an end part of that reinforcing plate, in contact with the second part of the flange;
- the beveled end part of the reinforcing plate assumes the form of an elongated bevel extending along the second part of the flange;
- the assembly comprises an intermediate plate, fixed between the flange and the reinforcing plate;
- the intermediate plate extends, at its end in contact with the second part of the flange, beyond the end part of the reinforcing plate;
- the intermediate plate is made from a composite material or a metal material, such as aluminum or titanium;
- the intermediate plate has a thickness comprised between 0.1 mm and 3 mm;
- the beveled part of the reinforcing plate is an end part of that plate;
- the reinforcing plate comprises:
- a first part attached against the first part of the flange,
- a second part, situated in the extension of the first part of the reinforcing plate and forming the beveled part of that reinforcing plate, said second part of the reinforcing plate being attached against the second part of the flange, and
- a third part, situated in the extension of the beveled part of the reinforcing plate and attached against the second part of the flange.
- the third part of the reinforcing plate has a thickness comprised between 0.1 mm and 3 mm.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 is a partial cross-sectional view of an assembly of an air inlet structure and fan casing according to the prior art;

FIG. 2 is a partial cross-sectional view of the assembly of FIG. 1 at the interface between a flange of the assembly and a reinforcing plate of that flange;

FIG. 3 is a partial cross-sectional view of a flange according to a first form of the present disclosure, said flange being able to be used in an assembly as shown in FIG. 1;

FIG. 4 is a partial cross-sectional view of a flange according to a second form of the present disclosure, said flange being able to be used in an assembly as shown in FIG. 1;

FIG. 5 is a partial cross-sectional view of a flange according to a third form of the present disclosure, said flange being able to be used in an assembly as shown in FIG. 1; and

FIG. 6 is a partial cross-sectional view of a flange according to a fourth form of the present disclosure, said flange being able to be used in an assembly as shown in FIG. 1.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
In general, and as shown in FIGS. 3 to 6 appended hereto, the present disclosure relates to an assembly for an aircraft nacelle comprising:

- a flange 30 including at least a first part 31 intended to be fixed to another flange 40 and a second part 32 extending transversely relative to the first part 31 intended to be fixed on a panel of said assembly, and
- a reinforcing plate 330, 332, 334 directly attached on the flange 30 or, optionally, indirectly by means of an intermediate plate 36 fixed between the reinforcing plate 330, 332, 334 and the flange 30, said reinforcing plate 330, 332, 334 having a beveled part across from the second part 32 of the flange 30.

In another form, the part 32 may be fixed on an acoustic panel of said assembly.
The beveled part of the reinforcing plate 330, 332, 334 makes it possible to limit the dimension of a bead in the flange 30, as shown in FIG. 2, or to avoid the formation of such a bead.
The beveled shape further allows a better transition in the stiffness between the flange 30 and the shroud panel on which it is fixed.
A first form of the present disclosure is described with the help of FIG. 3.
According to this first form, the reinforcing plate 330 comprises a beveled end part 331, which is in direct contact with the second part 32 of the flange 30.
The fact that the beveled end 331 of the reinforcing plate 330 is in contact with the second part 32 of the flange 30 limits the dimension of the bead as shown in FIG. 2, that bead being able to be formed on the part 32 when the reinforcing plate 330 is attached directly on the flange 30 and exerts pressure on the flange 30 to shape and define its radius of curvature.
The beveled shape allows a more gradual stiffness transition between the shroud and the flange 30 and increases the mechanical strength in the transition area between the flange 30 and the shroud;
It should be noted that this reinforcing plate 330 may be made from a composite material, independently from the flange 30.
To that end, the reinforcing plate 330 may be produced by RTM injection, infusion or autoclave curing.
It is generally pre-cured, then attached on the flange 30 on the plies of the flange that are not yet polymerized.
In non-limiting alternative forms, this reinforcing plate 330 may comprise pre-impregnated plies, dry fabric, woven preforms or short fibers.
The reinforcing plate 30 may also be metallic.
The reinforcing plate 330 thus has a stiffness allowing it to perform its reinforcing function of the flange 30.
A second form of the present disclosure is described with the help of FIG. 4.
In the second form, the reinforcing plate 332 has an end part that is also beveled, assuming the form of an elongated bevel 333 extending over the majority of the length of the second part 32 of the flange 30, or over the entire length of the second part 32 of the flange 30, directly in contact with the flange 30.
This elongated shape 333 is advantageous inasmuch as it makes it possible to better distribute the effect of the pressure on the second part 32 of the flange 30, relative to the first form, the bead that may be formed when the reinforcing plate 332 is attached directly on the flange 30 is smaller, or is even eliminated.
The reinforcing plate 332 may be manufactured in the same way as the reinforcing plate 330 of the first form and comprise identical components.
A third form of the present disclosure is described with the help of FIG. 5.
In this third form, the reinforcing plate 330, which is identical to the reinforcing plate described in the first form, is no longer directly attached against the flange 30.
In fact, in this form, an intermediate plate 36 is provided, fixed between the flange 30 and the reinforcing plate 330.
This intermediate plate 36 is an alternative form of the preceding solution, which may, depending on the materials chosen to produce the plate, be easier to produce.
In this case, the intermediate plate 36 makes it possible to smooth the pressure applied on the plies of the part 32 of the flange 30 by the reinforcing plate 330-331 during curing.
Advantageously, and as illustrated in FIG. 5, this intermediate plate 36 is attached against the first part 31 of the flange and extends at its end in contact with the second part 32 of the flange 30 beyond the beveled end part 331 of the reinforcing plate 330.
This makes it possible to still better distribute the forces applied to the flange 30, in this case to the second part 32 of the flange 30, by the reinforcing plate 330.
Thus, the intermediate plate 36 limits, or even eliminates, any punching phenomenon of the flange 30 that could occur when the assembly formed by the intermediate plate 36 and the reinforcing plate 330 is attached on the flange 30.
In fact, the reinforcing plate 330 and the intermediate plate 36 will generally be manufactured, then assembled to each other, before being attached together on the flange 30.
The intermediate plate 36 can be made from a composite material, for example with components identical to those of the reinforcing plate 330.
In another form, this intermediate plate 36 may be made from a metal material such as aluminum or titanium.
Furthermore, the intermediate plate 36 typically has a thickness comprised between 0.1 and 3 mm.
A fourth form of the present disclosure is described with the help of FIG. 6.
This fourth form offers the advantages of the third form.
However, in this fourth form, the reinforcing part 334 has a shape comparable to the shape obtained, for the third form, once the reinforcing plate 330 and the intermediate plate 36 have been assembled.
Thus, the reinforcing plate 334 comprises:
a first part 335 attached against the first part 31 of the flange 30,
a second part 336, situated in the extension of the first part 335 of the reinforcing plate 334 and forming the beveled part of that reinforcing plate 334, said second part 336 of the reinforcing plate 334 being attached against the second part 32 of the flange 30, and
a third part 337, situated in the extension of the beveled part 336 of the reinforcing plate 334 and attached against the second part 32 of the flange 30.
Furthermore, the third part 337 of the reinforcing plate 334 can have a thickness smaller than that of the first 335 and second 336 parts of the reinforcing plate 334.
Its thickness may be comprised between 0.1 and 3 mm, as is the case of the thickness of the intermediate plate 36 described in the third form.
The reinforcing plate 334 can be made in the same way as the reinforcing plate 330 of the first form and comprise the same components.
Of course, the present disclosure is in no way limited to the forms described and shown, provided purely as an example.
Thus, for example, irrespective of the considered form, it should be noted that the present disclosure is not limited to L-shaped flanges, but may apply to other flanges having at least two parts that extend transversely relative to one another. This is for example the case of T-shaped flanges.

Claims

What is claimed is:

1. An assembly for an aircraft nacelle, comprising:

a flange including at least one first part fixed to another flange and one second part extending transversely relative to the first part, the second part being fixed on a panel of said assembly; and

a reinforcing plate attached to the flange, said reinforcing plate having a beveled part across from the second part of the flange.

2. The assembly according to claim 1, wherein the beveled part of the reinforcing plate is an end part of that reinforcing plate, in contact with the second part of the flange.

3. The assembly according to claim 2, wherein the beveled end part of the reinforcing plate assumes a form of an elongated bevel extending along the second part of the flange.

4. The assembly according to claim 1, wherein it further comprises an intermediate plate, fixed between the flange and the reinforcing plate.

5. The assembly according to claim 4, wherein the intermediate plate extends, at its end in contact with the second part of the flange, beyond the end part of the reinforcing plate.

6. The assembly according to claim 4, wherein the intermediate plate is made from a composite material or a metal material.

7. The assembly according to claim 6, wherein the intermediate plate is made from aluminum or titanium.

8. The assembly according to claim 4, wherein the intermediate plate has a thickness comprised between 0.1 mm and 3 mm.

9. The assembly according to claim 4, wherein the beveled part of the reinforcing plate is an end part of that plate.

10. The assembly according to claim 1, wherein the reinforcing plate comprises:

a first part attached against the first part of the flange;

a second part, situated in an extension of the first part of the reinforcing plate and forming the beveled part of that reinforcing plate, said second part of the reinforcing plate being attached against the second part of the flange; and

a third part, situated in an extension of the beveled part of the reinforcing plate and attached against the second part of the flange.

11. The assembly according to claim 10, wherein the third part of the reinforcing plate has a thickness comprised between 0.1 mm and 3 mm.