Method of machining a thin-walled structure

• US 9,364,930 B2
• Filed: 03/13/2013
• Issued: 06/14/2016
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Hethcock, J. Donn, Wolthuis, Scott, Brack, Robert, Oldroyd, Paul
• Primary Examiner(s): Koehler, Christopher M
• Application Number:
  US13/802,357
• Publication Number:
  US 20140259628A1
• Time in Patent Office: 1,189 Days
• Field of Search: 294/23, 294/24, 269/7, 269/8, 269/47
• US Class Current: 1/1
• CPC Class Codes: B23C 2228/25 Honeycomb
• CPC Class Codes: B23C 3/16 Working surfaces curved in two directions
• CPC Class Codes: B23K 10/00 Welding or cutting by means of a plasma
• CPC Class Codes: B23K 2101/02 Honeycomb structures
• CPC Class Codes: B23K 26/38 by boring or cutting
• CPC Class Codes: B23P 25/00 Auxiliary treatment of workpieces, before or during machining operations, to facilitate the action of the tool or the attainment of a desired final condition of the work, e.g. relief of internal stress
• CPC Class Codes: B23Q 3/065 for holding workpieces being specially deformable, e.g. made from thin-walled or elastic material
• CPC Class Codes: B23Q 3/086 using a solidifying liquid, e.g. with freezing, setting or hardening means
• CPC Class Codes: B26F 3/004 by means of a fluid jet methods for use of abrasive blasting for cutting B24C1/045; guns for abrasive fluid jets B24C5/02; perforating by non-mechanical means, e.g. by fluid jet B26F1/26
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material
• CPC Class Codes: Y10T 29/49998 Work holding

Abstract

A method of manipulating a thin-walled structure includes providing a thin-walled structure in a first unconstrained configuration, constraining the thin-walled structure to a first constrained configuration in which a first feature of the thin-walled structure is spatially located relative to the a second feature of the thin-walled structure in a predetermined manner, wherein an open volume of the thin-walled structure is constrained to maintain a predetermined open volume shape, and machining the thin-walled structure to a second constrained configuration in which the first feature of the thin-walled structure remains spatially located relative to the second feature of the thin-walled structure in the predetermined manner.

Claims

1. A method of manipulating a thin-walled structure, comprising:

providing a thin-walled structure in a first unconstrained configuration;

constraining the thin-walled structure to a first constrained configuration in which a first feature of the thin-walled structure is spatially located relative to a second feature of the thin-walled structure in a predetermined manner, wherein an open volume of the thin-walled structure is constrained to maintain a predetermined open volume shape; and

machining the thin-walled structure to a second constrained configuration in which the first feature of the thin-walled structure remains spatially located relative to the second feature of the thin-walled structure in the predetermined manner; and

wherein constraining the thin-walled structure to the first constrained configuration comprises providing a constrainer into the open volume of the thin-walled structure, the constrainer comprising at least partially solidified cetyl alcohol; and

wherein the constrainer further comprises at least one of a magnetic material and a ferrous material, and the constraining comprises selectively applying a magnetic force to the constrainer.

2. The method of claim 1, wherein the predetermined manner comprises locating the first feature and the second feature a predetermined distance from each other.

3. The method of claim 1, wherein constraining the thin-walled structure to a first constrained configuration comprises preventing movement of the thin-walled structure in at least one direction of in-plane compression that causes collapse of the thin-walled structure without substantial buckling of a cell wall of the thin-walled structure.

4. The method of claim 1, wherein at least one of the first feature and the second feature form a portion of a repeated geometric pattern of the thin-walled structure.

5. The method of claim 1, wherein the constraining the thin-walled structure to a first constrained configuration comprises locating the thin-walled structure in a predetermined spatial location relative to a datum of a tool configured to perform the machining.

6. The method of claim 1, wherein the thin-walled structure comprises at least one of (1) a predetermined relationship between lateral expansion and longitudinal compression and (2) a predetermined relationship between lateral compression and longitudinal extension.

7. The method of claim 1, wherein the thin-walled structure comprises a honeycomb core material comprising a carbon mesh material.

8. The method of claim 7, wherein the honeycomb core material comprises a cell size of about 0.5 inches.

9. The method of claim 1, wherein the open volume is accessible from outside of the thin-walled structure.

10. The method of claim 9, wherein the constrainer comprises a bottle brush.

11. The method of claim 1, wherein the machining is generally conducted along a path that is generally perpendicular to a central axis of a cell of the thin-walled structure.

12. The method of claim 1, wherein the thin-walled structure is a core material configured for use in a composite blade component and wherein the machining comprises contouring the thin-walled structure to complement a surface of a composite shell of the composite blade component.

13. The method of claim 1, further comprising washing away the cetyl alcohol using isopropyl alcohol.

14. A method of machining, comprising:

providing a thin-walled structure in a first unconstrained configuration;

constraining the thin-walled structure to a first constrained configuration that is different from the first unconstrained configuration, thereby providing a first spatial registration between a first feature of the thin-walled structure and a second feature of the thin-walled structure, and thereby providing a first spatial registration between the thin-walled structure and a datum of a tool as a function of the first spatial registration between the first feature and the second feature, wherein constraining the thin-walled structure to the first constrained configuration comprises providing a constrainer into an open volume of the thin-walled structure and selectively applying a magnetic force to the constrainer, the constrainer comprising at least partially solidified cetyl alcohol and at least one of a magnetic material and a ferrous material; and

operating the tool to machine the thin-walled structure to a second constrained configuration while maintaining the first spatial registration between the first feature and the second feature.

15. The method of claim 14, wherein the constraining locates the first feature and the second feature a predetermined distance from each other.

16. The method of claim 14, wherein the thin-walled structure comprises a compression strength in a direction parallel to a height of the thin-walled structure that is at least one order of magnitude greater than the compression strength of the thin-walled structure in a plurality of in-plane directions of the thin-walled structure.

17. The method of claim 14, wherein at least one of the first feature and the second feature form a portion of a repeated geometric pattern of the thin-walled structure.

18. The method of claim 14, wherein the machining is conducted along a path that is generally perpendicular to a central axis of a cell of the thin-walled structure.

19. The method of claim 14, wherein the open volume is accessible from outside of the thin-walled structure.

20. The method of claim 19, wherein the constrainer comprises a bottle brush.

21. The method of claim 14, further comprising providing a second spatial registration between the thin-walled structure and a datum of a tool as a function of the first spatial registration between the first feature and the second feature.

22. A method of manipulating a structure, comprising:

providing a thin-walled structure in a first unconstrained configuration, the thin-walled structure comprising a plurality of open volumes accessible from outside of the thin-walled structure; and

constraining the thin-walled structure to a first constrained configuration by inserting a constrainer into at least one of the plurality of open volumes in a first state and changing the constrainer from the first state to a second state, wherein the constrainer comprises at least partially solidified cetyl alcohol and at least one of a magnetic material and a ferrous material.

23. The method of claim 22, wherein the changing the constrainer from the first state to the second state comprises solidifying at least a portion of the constrainer.

24. The method of claim 22, wherein the changing the constrainer from the first state to the second state comprises increasing a packing density of the constrainer.

25. The method of claim 22, wherein the constrainer comprises a bottle brush.

26. The method of claim 22, wherein the changing the constrainer from the first state to the second state comprises applying a magnetic force to the constrainer.