초록 ▼

The invention provides a fan cowl (11) of an aircraft engine made of a composite material having an optimized structure for withstanding the expected loads and for being able to be manufactured as a monolithic ensemble. The structure comprise a skin (13), frames (15) of a closed cross-section arrang

The invention provides a fan cowl (11) of an aircraft engine made of a composite material having an optimized structure for withstanding the expected loads and for being able to be manufactured as a monolithic ensemble. The structure comprise a skin (13), frames (15) of a closed cross-section arranged in a transverse direction to the longitudinal axis of the aircraft and longitudinal beams (17, 19) comprising first parts (21) of a closed cross-section to be superimposed to the transverse frames (15) in their crossing zones and second parts (23) of an open cross-section in zones not crossing transverse frames (15) having their webs (41) arranged in a same plane. The invention also refers to a manufacturing method of said fan cowl (11).

대표청구항 ▼

1. A curvilinear fan cowl of an aircraft engine, made of a composite material and having a longitudinal axis parallel to a longitudinal axis of an aircraft to which is attached the fan cowl, the fan cowl comprising: a skin, transverse frames and longitudinal beams, wherein the transverse frames and

1. A curvilinear fan cowl of an aircraft engine, made of a composite material and having a longitudinal axis parallel to a longitudinal axis of an aircraft to which is attached the fan cowl, the fan cowl comprising: a skin, transverse frames and longitudinal beams, wherein the transverse frames and longitudinal beams are orthogonal with each other and attached to an inside surface of the skin;the transverse frames comprise a frame cap spaced from the skin, frame webs each extending from the frame cap towards the skin, and frame feet adjacent the skin and each extending from one of the frame webs;the longitudinal beams being formed by at least a first part in a zone crossing one of the transverse frames and at least a second part in a zone not crossing any of the transverse frames;each first part comprising a first cap overlapping the one of the transverse frames, first webs extending from the first cap towards the skin, and first feet proximate the skin and each extending from one of the first webs, and each first part having a shape in cross section configured to seat on the one of the transverse frames,wherein each second part of the longitudinal beams comprises a second cap spaced from the skin, a second web extending from the second cap towards the skin, and a foot adjacent the skin and extending from the second web;wherein each of the second webs of the second parts of the longitudinal beams are arranged in a common plane;wherein a width of the first cap on one side of the common plane is greater than a width of the first cap on the other side of the common plane, andwherein the curvilinear fan cowl is a monolithic ensemble. 2. The curvilinear fan cowl according to claim 1, wherein the second cap includes a first portion having a constant width (W3) and which extends extending equally from both sides of the common plane, and the first cap has a width larger than twice W3. 3. The curvilinear fan cowl according to claim 2, wherein: the first cap comprise a first width (W1) extending from one side of the common plane and a second width (W2) extending from the other side of the common plane, wherein W2 is larger than W1;the second cap has an end cap having a recess at one side of the common plane, andthe second cap has a variable width on the other side of the common plane, which variable width increases from W1 to W2. 4. The curvilinear fan cowl according to claim 1, wherein the second part includes a rib transverse to the second web. 5. The curvilinear fan cowl according to claim 1, wherein at least one of the longitudinal beams comprise a second part with a central portion of a variable height. 6. The curvilinear fan cowl according to claim 1, wherein the transverse frames are omega-shaped in cross-section. 7. The curvilinear fan cowl according to claim 1, comprising at least two of the longitudinal beams which each overlaps the transverse frames. 8. The curvilinear fan cowl according to claim 7, wherein at least one of the longitudinal beams overlaps only a group of less than all of the transverse frames. 9. A method of manufacturing a curvilinear fan cowl comprising: a) providing an uncured skin, cured transverse frames, and cured longitudinal beams, wherein the transverse frames and the longitudinal beams include respectively adhesive layers against inner faces of the transverse frames and the longitudinal beams, wherein each of the longitudinal beams includes a cap and a portion of the cap at a region of the beam overlapping one of the transverse frames in asymmetrical with respect to a plane defined by a web of the beam extending longitudinally along the beam such that a width of the cap at the region is greater on one side of the plane than a width of the cap on the other side of the plane;b) placing the uncured skin on an autoclave tool;c) placing said transverse frames with internal vacuum bags on the uncured skin, wherein the vacuum bags being used during an autoclave cycle;d) placing said longitudinal beams over the transverse frames and the skin;e) covering with another vacuum bag an assembly of the uncured skin, the transverse frames with the internal vacuum bags and the longitudinal beams; andf) performing on the assembly the autoclave cycle under predetermined temperature and pressure conditions for co-bonding the skin, the transverse frames and the longitudinal beams and for a secondary bonding of the longitudinal beams to the transverse frames. 10. The method according to claim 9, wherein the step d) also comprises placing a shim layer over the areas of transverse frames to be crossed by the longitudinal beams. 11. The method according to claim 9, also comprising laying-up patches of a corrosion protection layer in those locations of the skin, the transverse frames and the longitudinal beams foreseen for the installation of metallic fittings. 12. The method according to claim 9, wherein in step a) the uncured skin is provided with a lightening protecting layer in its outer face. 13. A fan cowl for an aircraft engine comprising: a composite material skin configured to extend around the aircraft engine;composite material transverse frames attached to an inside surface of the skin and extending circumferentially with respect to an axis of the fan cowl, wherein the transverse frames are spaced apart in an axial direction with respect to the axis;composite material beams attached to the inside surface of the skin and extending in the axial direction, wherein the beams include a first part overlapping one of the transverse frames and a second part extending between adjacent ones of the transverse frames,the first part of each beam including a first cap, a pair of first webs extending from the first cap, and first feet extending from first webs and proximate the skin, wherein the first cap and pair of first webs are configured to overlap sides of the one of the transverse frames, andthe second part of each beam includes a second cap, a second web extending from the second cap, and a foot extending from the second web and adjacent the skin, wherein the second web defines a plane;wherein the first cap extends a first axial distance (W1) from the plane and extends a second axial distance (W2) on an opposite side of the plane, and W1 is smaller than W2. 14. The fan cowl of claim 13 wherein the second cap gradually increases in width in a direction towards the first cap. 15. The fan cowl of claim 14 wherein the gradual increase in the width on a single side of the second cap. 16. The fan cowl of claim 13 wherein the first cap and the second cap are formed of a single piece composite material. 17. The fan cowl of claim 13 wherein an axial end of the pair of first webs ends at W1.