Composite fabrication method and tooling to improve part consolidation

• US 6,217,000 B1
• Filed: 09/30/1998
• Issued: 04/17/2001
• Est. Priority Date: 10/25/1996
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Kovach, Daniel J., Younie, Mark L., Bower, Jeffrey C., Nishimura, James T.
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): WARD, JESSICA LEE
• Application Number:
  US09/164,433
• Time in Patent Office: 930 Days
• Field of Search: 249/184, 264/258, 264/313, 425/403, 244/123, 244/124, 244/125, 244/126
• US Class Current: 249/184
• CPC Class Codes: B29C 2043/3649 Inflatable bladders using gas or fluid and related details
• CPC Class Codes: B29C 2945/7604 Temperature
• CPC Class Codes: B29C 2945/76287 Moulding material
• CPC Class Codes: B29C 33/38 characterised by the material or the manufacturing process B29C33/44 takes precedence
• 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: B29D 99/0003 Producing profiled members, e.g. beams
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

A method and tooling concept for fabricating complex composite parts is provided. The method and tooling concept use various tooling configurations in order to produce varying magnitudes of thermal expansion at different areas within the tooling concept. The varying magnitudes of thermal expansion allow the tool concept to account for varying magnitudes of tool movement needed to debulk and consolidate varying thickness areas of the composite workpiece being cured. The tooling concept is formed of different materials having different thicknesses that allow the tooling concept to produce varying magnitudes of thermal expansion. The exterior surface of the tooling concept is covered by a compliant covering. The compliant covering helps to equalize the consolidation pressures produced by the tooling concept during curing. A composite wing box structure fabricated using the method and tooling concept is also disclosed.

Claims

1. A tooling concept for forming a composite part having a cavity therein and formed of composite material, comprising:

a plurality of rigid tools that are assembled together to form the tooling concept, the plurality of tools including a base tool having opposite side edges, opposing side tools extending along the base tool opposite side edges, respectively, each of the side tools having an inner surface facing the inner surface of the other of the side tools, a first side tool mount fastened to one of the side tools at the inner surface thereof and fastened to the base tool for positioning said one side tool relative to the base tool, a second side tool mount fastened to the inner surface of the other of the side tools and fastened to the base tool for positioning said other of the side tools relative to the base tool, the side tools having exterior surfaces remote from each other and being positioned with their inner surfaces spaced apart, the interior of the tooling concept between the side tool mounts being open;

the tooling concept being configured so that composite material for forming the composite part can be laid up around the tooling concept so that the tooling concept is within the cavity of the eventually-formed composite part; and

the plurality of rigid tools being configured so that they can be disassembled and removed through an opening of the cavity after formation of the composite part by unfastening the side tool mounts from the base mount and removing the side tool mounts, side tools and the base tool through the opening in the cavity.

2. The tooling concept of claim 1, in which the base tool has opposite end edges, and the rigid tools including opposing end tools extending along the base tool opposite end edges, respectively, each of the end tools having an inner surface facing the inner surface of the other of the end tools, a first end tool mount fastened to one of the end tools at the inner surface thereof and fastened to the base tool for positioning of said one end tool relative to the base tool, a second end tool mount fastened to the inner surface of the other of the end tools and fastened to the base tool for positioning said other of the end tools relative to the base tool, the end tools having exterior surfaces remote from each other and being positioned with their inner surfaces spaced apart, the interior of the tooling concept between the end and side tool mounts being open, the plurality of rigid tools being configured so that they can be disassembled and removed through an opening in the cavity after formation of the composite part by unfastening the end and side tool mounts from the base tool and removing the end and side tool mounts, the end and side tools and the base tool through the opening in the cavity.

3. The tooling concept of claim 1, in which the rigid tools include a top tool fastened to the side tool mounts, the plurality of rigid tools being configured so that they can be disassembled and removed through an opening of the cavity after formation of the composite part by unfastening the top tool from the side tool mounts and removing the top tool, side tool mounts, side tools and the base tool through the opening in the cavity.

4. The tooling concept of claim 1, in which the base tool has recesses in an upper surface thereof and the side tools have base portions fitted and fastened in the recesses.

5. The tooling concept of claim 1, wherein the plurality of rigid tools are individually indexed relative to each other whereby small adjustments can be made relative to each other.

6. The tooling concept of claim 1, wherein the plurality of rigid tools are formed of a material having a coefficient of thermal expansion greater than the coefficient of thermal expansion of composite material used to form the composite part.

7. The tooling concept of claim 1, wherein the tooling concept is configured so that some areas of the tooling concept expand more than other areas of the tooling concept during curing of the composite part.

8. The tooling concept of claim 1, further comprising a compliant covering in the regions of the tooling concept that come into contact with a composite material formed on the tooling concept.

9. The tooling concept of claim 8, wherein the compliant covering has varying thicknesses at different locations within the compliant covering.

10. The tooling concept of claim 8, wherein the compliant covering comprises silicon rubber.