Method and Apparatus for Fabricating Large Scale Integrated Airfoils

• US 20130149164A1
• Filed: 12/13/2011
• Published: 06/13/2013
• Est. Priority Date: 12/13/2011
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Hansen, Martin Wayne
• Granted Patent: US 9,017,510 B2
• Time in Patent Office: Days
• US Class Current: 416/226
• CPC Class Codes: B29C 35/0227 using pressure vessels, e.g. autoclaves, vulcanising pans B29C35/065 takes precedence
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 65/4835 Heat curing adhesives
• CPC Class Codes: B29C 65/5042 covering both elements to be joined
• CPC Class Codes: B29C 65/7841 Holding or clamping means for handling purposes clamping means for the purpose of applying pressure on the parts to be joined, in the area to be joined B29C66/81; work holders in general B25B; devices for holding or positioning work for welding metal B23K37/04
• CPC Class Codes: B29C 65/7855 Provisory fixing
• 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 66/114 Single butt joints
• CPC Class Codes: B29C 66/1162 Single bevel to bevel joints, e.g. mitre joints
• CPC Class Codes: B29C 66/12464 being V-shaped
• 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 66/43441 with two right angles, e.g. for making T-shaped pieces, H-shaped pieces
• 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 66/73751 the to-be-joined area of at least one of the parts to be joined being uncured, i.e. non cross-linked, non vulcanized
• CPC Class Codes: B29C 66/73755 the to-be-joined area of at least one of the parts to be joined being fully cured, i.e. fully cross-linked, fully vulcanized
• CPC Class Codes: B29C 66/73756 the to-be-joined areas of both parts to be joined being fully cured
• CPC Class Codes: B29C 66/7394 characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 70/44 : using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
• CPC Class Codes: B29C 70/46 : using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs
• CPC Class Codes: B29C 70/549 : Details of caul plates, e.g. materials or shape
• CPC Class Codes: B29D 99/0025 : Producing blades or the like, e.g. blades for turbines, propellers, or wings
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2307/04 : Carbon
• CPC Class Codes: B29L 2031/3085 : Wings
• CPC Class Codes: B64C 3/185 : Spars
• CPC Class Codes: B64C 3/26 : Construction, shape, or attachment of separate skins, e.g. panels
• CPC Class Codes: B64F 5/10 : Manufacturing or assembling aircraft, e.g. jigs therefor
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02T 50/40 : Weight reduction
• CPC Class Codes: Y10T 156/17 : Surface bonding means and/or assemblymeans with work feeding or handling means

Abstract

An airfoil is fabricated by assembling cured skins with spars having cured spar webs and uncured spar chords. The skins are bonded to the spars by curing the spar chords.

Claims

1. A method of fabricating an airfoil, comprising:

making a pair of cured composite skins;

making at least one spar, including assembling uncured spar chords and at least one cured composite spar web;

assembling the cured skins to the spar; and

curing the spar chords.

2. The method of claim 1, further comprising:

compacting the spar chords against the cured skins.

3. The method of claim 1, wherein assembling the skins and the spar includes:

holding the spar web and the spar chords in a tool, and

mounting the skins on the tool with an inner mold line of each of the skins in proximity to the spar chords.

4. The method of claim 3, wherein holding the spar web and the spar chords in the tool includes:

adhering the spar chords to the spar web, and

clamping the spar web in the tool.

5. The method of claim 3, wherein assembling the cured skins and the spar includes:

forming holes in each of the skins, and

removably mounting the skins on the tool by inserting pins through the holes into the tool.

6. The method of claim 4, wherein assembling the cured skins and the spar includes indexing the spar relative to the cured skins by mounting the tool on indexing rods.

7. The method of claim 2, wherein:

assembling the skins and the spar includes holding the spar web and the spar chords in a tool, and mounting the skins on the tool with an inner mold line of each of the skins in proximity to the spar chords, and

compacting the spar chords against the skins is performed by installing vacuum bags on the tool respectively covering the spar chords, and evacuating the vacuum bags.

8. The method of claim 1, wherein assembling the cured skins and the spar includes:

placing a tool on an assembly fixture,

assembling the cured spar web and the uncured spar chords on the tool, and

transferring the tool having the assembled spar web and spar chords to a cure fixture.

9. The method of claim 1, wherein assembling the uncured spar chords and at the least one cured composite spar web includes pre-compacting the spar chords against the at least one uncured spar web.

10. The method of claim 9, wherein the pre-compacting includes:

placing chord compaction tools respectively against the spar chords, and

compacting of the chord compaction tools respectively against the spar chords.

11. The method of claim 10, wherein:

assembling the skins and the spar includes transferring the spar and the spar compaction tools to an internal tool, and mounting the skins on the internal tool with an inner mold line of each of the skins in proximity to the spar chords, and

curing the spar chords includes using the spar compaction tools to compact the spar chords against the skin and the at least one spar web.

12. An airfoil fabricated by the method of claim 1.

13. A method of fabricating an airfoil box, comprising:

providing a pair of cured composite skins each having a span;

assembling at least one composite spar, including attaching uncured composite spar chords to a cured composite spar web;

holding the spar and the cured skins in an assembled, indexed relationship to each other along the span; and

bonding the spar to the cured composite skins by curing the uncured composite spar chords.

14. The method of claim 13, further comprising:

generating a compaction force compacting the spar chords against the spar web and the skins as the spar chords are being cured.

15. The method of claim 14, wherein compacting the spar chords includes:

installing vacuum bags respectively over the spar chords, and

evacuating each of the vacuum bags.

16. The method of claim 14, wherein the skins and the spar webs are used to react the compaction force.

17. The method of claim 13, wherein assembling the spar includes:

laying up and curing the composite spar web,

laying up and forming the composite spar chords,

applying an adhesive to one of the spar web and the spar chords,

assembling the spar web and the spar chords together, and

compacting the spar web and the spar chords together.

18. The method of claim 13, further comprising:

assembling the spar and the skins, including placing the assembled spar in a tool, attaching the skins to the tool, and transferring the assembled skins and spar to a cure fixture.

19. The method of claim 18, wherein the curing is performed by:

placing the cure fixture in an autoclave, and

subjecting substantially only the spar chords to autoclave pressure.

20. An apparatus for fabricating an airfoil box, comprising:

a tool adapted to hold at least one composite spar between two skins with uncured portions of the spar in proximity to the skins; and

a fixture for supporting the tool during curing of the uncured portions of the spar.

21. The apparatus of claim 20, wherein the tool includes first and second tool portions between which a spar may be clamped and to which the skins may be attached.

22. The apparatus of claim 21, wherein each of the tool portions includes at least one vacuum bag for compacting the uncured portions of the spar during the curing.

23. The apparatus of claim 20, wherein the fixture includes a plurality of align indexing rods passing through and supporting the tool.

24. The apparatus of claim 21, wherein the tool includes a clamp for clamping the first and second tool portions against the spar.