Airframe production

• US 10,364,046 B2
• Filed: 04/10/2015
• Issued: 07/30/2019
• Est. Priority Date: 04/24/2014
• Status: Active Grant

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Sanderson, Steven Neil
• Primary Examiner(s): Goff, II, John L
• Application Number:
  US15/304,361
• Publication Number:
  US 20170043529A1
• Time in Patent Office: 1,572 Days
• CPC Class Codes: B29C 65/48 using adhesives , i.e. using supplementary joining material; solvent bonding
• CPC Class Codes: B29C 66/00145 Vacuum, e.g. partial vacuum
• CPC Class Codes: B29C 66/01 General aspects dealing with the joint area or with the area to be joined B29C65/76, B29C65/82 take precedence
• CPC Class Codes: B29L 2031/3076 Aircrafts blades, propellers B29L2031/08
• CPC Class Codes: B64F 5/10 Manufacturing or assembling aircraft, e.g. jigs therefor
• CPC Class Codes: B64F 5/45 Repairing leakages in fuel tanks
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing

Abstract

Disclosed is a method of producing part of an airframe for attachment to a system. The method comprises: providing an initial structure; providing a reference structure; positioning the initial structure with respect to the reference structure such that its position/orientation relative to the reference structure is the same as the position/orientation relative to the system that it would have if the part of the airframe was attached to the system; specifying an inner mold line; applying, to an outer surface of the initial structure, material; and machining the material such that the position/orientation of the outer surface of the material with respect to the reference structure is the same as the position/orientation with respect to the system that the inner mold line would have if the part of the airframe was attached to the system.

Claims

1. A method of producing a first part of an aircraft airframe, the first part of the airframe being for attachment to a second part of an aircraft airframe, the method comprising:

providing an initial structure, the initial structure being part of the first part of the aircraft airframe to be produced;

providing a reference structure representative of the second part of the airframe;

positioning the initial structure with respect to the reference structure such that the position and orientation of the initial structure relative to the reference structure is the same as the position and orientation relative to the second part of the airframe that the initial structure would have if the first part of the aircraft airframe was attached to the second part of the airframe;

specifying a surface, the surface being a desired inner mould line for the first part of the aircraft airframe;

applying, to an outer surface of the initial structure, one or more layers of material; and

after the one or more layers of material have been applied to the initial structure, machining, using a cutting device, the layers of material such that the position and orientation of the outer surface of the layers of material with respect to the reference structure is the same as the position and orientation with respect to the second part of the airframe that the specified surface would have if the first part of the aircraft airframe was attached to the second part of the airframe;

measuring a plurality of points on a surface of the reference structure; and

using the measurements of the surface of the reference structure, determining a datum; and

the step of machining comprises controlling the cutting device with respect to the datum.

2. A method according to claim 1, wherein the first part of the airframe is at least part of an aircraft aft fuselage, and the second part of the airframe is at least part of an aircraft fore section.

3. A method according to claim 1, wherein the step of providing an initial structure comprises:

providing a plurality of components of the first part of the airframe;

for each component, determining a position and orientation relative to the second part of the airframe that that component would have if the first part of the airframe was attached to the second part of the airframe;

arranging the components of the first part of the airframe such that the position and orientation of each of said components relative to the reference structure is the same as the determined position and orientation of that component relative to the second part of the airframe; and

attaching together the components such that the relative positions and orientations of those components are maintained.

4. A method according to claim 2, wherein each component is selected from a group of airframe components consisting of frames, longerons, keels, and beams.

5. A method according to claim 1, wherein the step of applying the one or more layers of material to an outer surface of the initial structure comprises:

providing an over press tool having a face that is complementary to at least part of the outer surface of the initial structure to which the one or more layers of material is to be applied;

applying, to at least part of the outer surface of the initial structure, using an adhesive, the one or more layers of material;

at least for some time during curing of the adhesive;

positioning the over press tool such that the face of the over press tool is in contact with an outer surface of the one or more layers of material and the one or more layers of material are between the surface of the initial structure and the face of the over press tool; and

forcing the over press tool against the initial structure such that the over press tool exerts a normal force on the initial structure; and

thereafter removing the over press tool from the one or more layers of material.

6. A method according to claim 5, wherein the face of the over press tool is a deformable surface.

7. A method according to claim 5, wherein

the over press tool comprises one or more clamp receiving elements;

and

the step of forcing comprises clamping, using one or more clamps, the over press tool to the initial structure.

8. A method according to claim 5, wherein the step of forcing comprises an actuation device forcing the over press tool against the initial structure.

9. A method according to claim 5, wherein the step of applying comprises coupling the one or more layers of material to the face of the over press tool and, subsequently, moving the over press tool with the one or more layers of material coupled thereto in such a way that the one or more layers of material are pressed against the outer surface of the initial airframe component.

10. A method according to claim 9, wherein the one or more layers of material are held against the over press tool by a vacuum.

11. A method according to claim 1, wherein the one or more layers are made of a composite material.