METHOD OF MANUFACTURING AN INTEGRAL PROFILE MONOLITHIC WING STRUCTURE

• US 20100193636A1
• Filed: 06/30/2008
• Published: 08/05/2010
• Est. Priority Date: 07/11/2007
• Status: Active Grant

• Current Assignee: Alenia Aeronautica SPA (Leonardo S.p.A.)
• Original Assignee: Alenia Aeronautica SPA (Leonardo S.p.A.)
• Inventors: Miani, Nicola, Inserra Imparato, Sabato, Lanfranco, Giovanni, De Vita, Vincenzo, Sagnella, Giovanni, Riccio, Massimo
• Granted Patent: US 8,980,152 B2
• Time in Patent Office: Days
• US Class Current: 244/123.1
• CPC Class Codes: B29C 2035/0822 using IR radiation
• CPC Class Codes: B29C 65/50 using adhesive tape , e.g. thermoplastic tape; using threads or the like B29C65/3444 takes precedence
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/1282 comprising at least one overlap joint-segment
• CPC Class Codes: B29C 66/12822 comprising at least three overlap joint-segments
• CPC Class Codes: B29C 66/12841 comprising at least two butt joint-segments
• CPC Class Codes: B29C 66/12842 comprising at least three butt joint-segments
• CPC Class Codes: B29C 66/131 Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
• CPC Class Codes: B29C 66/14 the joint having the same thickness as the thickness of the parts to be joined B29C66/1142 takes precedence
• CPC Class Codes: B29C 66/474 said single elements being substantially non-flat
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/543 joining more than two hollow-preforms to form said hollow articles
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7212 characterised by the composition of the fibres
• CPC Class Codes: B29C 66/72141 Fibres of continuous length
• CPC Class Codes: B29C 66/7254 honeycomb structures
• CPC Class Codes: B29C 66/727 being porous, e.g. foam
• CPC Class Codes: B29C 66/73161 Roughness or rugosity
• CPC Class Codes: B29C 66/73752 : the to-be-joined areas of both parts to be joined being uncured
• CPC Class Codes: B29C 66/73941 : characterised by the materials of both parts being thermosets
• CPC Class Codes: B29C 66/81455 : being a fluid inflatable bag or bladder, a diaphragm or a vacuum bag for applying isostatic pressure inflatable element positioned between the joining tool and a backing-up part B29C66/82421
• CPC Class Codes: B29C 70/345 : using matched moulds
• CPC Class Codes: B29C 70/543 : Fixing the position or configuration of fibrous reinforcements before or during moulding for non-woven fabrics D04H3/08
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/246 : Uncured, e.g. green
• CPC Class Codes: B29K 2307/04 : Carbon
• CPC Class Codes: B29K 2309/08 : Glass
• CPC Class Codes: B29K 2707/04 : Carbon
• CPC Class Codes: B29L 2031/3085 : Wings
• CPC Class Codes: B29L 2031/608 : Honeycomb structures
• CPC Class Codes: B64C 3/24 : Moulded or cast structures
• CPC Class Codes: Y02T 50/40 : Weight reduction

Abstract

A method of manufacturing a wing structure includes laying a plurality of layers of preimpregnated material on a first mould half and on a second mold half so as to form a first fresh skin and a second fresh skin of the wing structure. A plurality of layers of preimpregnated material are laid in succession on a shaped apparatus to form a fresh leading edge skin of the wing structure. Fresh spars of preimpregnated material are formed. A wedgelike body of expanded plastics material is formed, this body being designed to be interposed between the first and second skins at the trailing edge of the wing structure. The fresh spars are positioned in a coordinated way on the first fresh skin, removable support members also positioned next to the spars. The second mold half is turned over on to the first mold half so as to position the second fresh skin on the spars and the supports, to produce a fresh wing structure. The fresh wing structure is subjected to a polymerization cycle, using a vacuum bag.

Claims

1. A method of manufacturing a wing structure (10), comprising the following stages:

laying in succession on a first mould half (51) a plurality of layers of preimpregnated material so as to form a first fresh skin (22) of said wing structure;

laying in succession on a second mould half (52) a plurality of layers of preimpregnated material so as to form a second fresh skin (21) of said wing structure;

forming a plurality of fresh spars (30), each of said spars comprising a plurality of layers of preimpregnated material;

positioning said fresh spars in a coordinated way on the first fresh skin (21), using removable support members (100) on which the spars have previously been positioned;

turning over the second mould half and placing it on the first mould half so as to position said second fresh skin on said spars and said support means, so as to produce a fresh wing structure; and

subjecting said fresh wing structure to a polymerization cycle, using a vacuum bag,

characterized in that it also comprises the following stages;

laying in succession on a shaped apparatus (80) a plurality of layers of preimpregnated material so as to form a fresh leading edge skin (23) of said wing structure;

forming a wedgelike body (40) of light expanded plastics material, said wedgelike body being designed to be interposed between said first and second skins at the trailing edge of said wing structure;

on completion of the stage of placing the fresh spars on the first fresh skin (21), positioning said wedgelike body on the first fresh skin, in such a way that, when said second fresh skin is positioned on said spars, said fresh leading edge skin is connected to said first and second fresh skins, and said wedgelike body is interposed between said first and second fresh skins;

in such a way as to obtain, at the end of the polymerization cycle, a wing structure with a controlled integral profile, free of mechanical connecting members.

2. A method according to claim 1, in which said wedgelike body is made from closed-cell foam.

3. A method according to claim 2, in which said wedgelike body is made from Rohacell®

.

4. A method according to any one of claims 1 to 3, in which said wedgelike body is machined so as to have a height greater than the nominal dimension which it has inside said structure at the end of polymerization.

5. A method according to any one of the preceding claims, in which one or more stiffening elements (60) of honeycomb material are interposed between the layers of preimpregnated material to form a sandwich, these elements being positioned in a predetermined way in areas where greater structural stiffness is required.

6. A method according to claim 5, in which said honeycomb material is made from Nomex®

.

7. A method according to claim 5 or 6, in which said stiffening elements are produced by machining the honeycomb material so as to produce semi-finished products (61) with a trapezoidal cross section.

8. A method according to any one of claims 5 to 7, in which said honeycomb material is normally capable of withstanding pressures lower than the pressure of polymerization of the preimpregnated material.

9. A method according to claim 8, in which said stiffening elements are subjected, before said stage of interposition for forming a sandwich structure, to a stabilization process, in which they are covered with a preimpregnated fibre textile material and a peelable textile and are subjected to a polymerization cycle at a maximum pressure which is lower than the maximum pressure of the wing structure polymerization cycle.

10. A method according to claim 9, in which said fibre textile material is applied to said stiffening elements by means of a film of adhesive.

11. A method according to claim 10, in which said fibre textile material is made from carbon fibre.

12. A method according to any one of the preceding claims, in which the layers of preimpregnated material of said leading edge skin are connected to the layers of preimpregnated material of said first and second skins by means of a connection using staggered joints (21a, 23a, 22b, 23b).

13. A method according to any one of the preceding claims, in which the layers of preimpregnated material of each spar (30) are connected to the layers of preimpregnated material of an adjacent spar (30) by means of a connection using staggered joints (31g, 34g).

14. A method according to any one of the preceding claims, in which said preimpregnated material is based on carbon fibre.

15. A wing structure (10) produced by a method according to any one of the preceding claims.