Systems and methods for forming perforations in a barrel structure

Patent metadata

Field	Value
Publication number	US-11059106-B2
Application number	US-201815871958-A
Country	US
Kind code	B2
Filing date	Jan 15, 2018
Priority date	Aug 28, 2013
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A drilling system includes a single robotic drilling unit having a drill end effector positioned inside a barrel section configured as a composite sandwich structure having an inner face sheet. The robotic drilling unit is operable to drill a plurality of perforations into the inner face sheet using the drill end effector. The robotic drilling unit is configured to index a hole pattern of the perforations to one or more cell walls of a honeycomb core of the composite sandwich structure. The robotic drilling unit is configured to form the hole pattern in the inner face sheet such that the perforations are located at a spaced distance from the cell walls of the honeycomb core.

First claim

What is claimed is:

1. A drilling system, comprising:
a single robotic drilling unit having a drill end effector positioned inside a barrel section configured as a composite sandwich structure having an inner face sheet;
the single robotic drilling unit being operable to drill a plurality of perforations into the inner face sheet using the drill end effector;
the single robotic drilling unit is configured to index a hole pattern of the perforations to one or more cell walls of a honeycomb core of the composite sandwich structure; and
the single robotic drilling unit is configured to form the hole pattern in the inner face sheet such that the perforations are located at a spaced distance from the cell walls of the honeycomb core.

2. The drilling system of claim 1 , wherein:
the drill end effector is positioned inside a one-piece engine inlet inner barrel section cured in a single stage.

3. The drilling system of claim 1 , wherein:
the single robotic drilling unit is operated in a manner to drill the perforations such that a percent-open-area in one section of the inner face sheet is different than the percent-open-area in another section of the inner face sheet.

4. The drilling system of claim 1 , wherein:
the single robotic drilling unit has a robotic arm assembly being movable about at least five axes.

5. The drilling system of claim 1 , wherein:
the single robotic drilling unit has a drilling unit base positioned inside the barrel section.

6. A method of fabricating an engine inlet, comprising the steps of:
providing an engine inlet inner barrel section configured as a composite sandwich structure having an inner face sheet;
drilling, using a drill end effector of a single robotic drilling unit in which the drill end effector is positioned inside the barrel section, a plurality of perforations in the inner face sheet after final cure of the composite sandwich structure, wherein the drilling comprises indexing a hole pattern of the perforations to one or more cell walls of a honeycomb core of the composite sandwich structure, and positioning the hole pattern such that each perforation is located at a spaced distance from the cell walls; and
forming the plurality of perforations in a quantity providing a predetermined percent-open-area of the inner face sheet.

7. The method of claim 6 , wherein the step of providing the engine inlet inner barrel section comprises:
providing the engine inlet inner barrel section as a one-piece composite sandwich structure.

8. The method of claim 6 , wherein the step of drilling the plurality of perforations comprises:
drilling the perforations to provide a percent-open-area in one section of the inner face sheet that is different than the percent-open-area in another section of the inner face sheet.

9. The method of claim 6 , further comprising:
positioning a drilling unit base of the single robotic drilling unit inside the engine inlet inner barrel section prior to drilling the plurality of perforations.

10. The method of claim 6 , further comprising:
indexing the engine inlet inner barrel section and the single robotic drilling unit to at least one fixture supporting the barrel section prior to drilling the plurality of perforations.

11. A drilling system, comprising:
a single robotic drilling unit having a drill end effector positionable inside a barrel structure supported on a system base;
the single robotic drilling unit being operable to drill a hole pattern of perforations into an inner surface of the barrel structure using the drill end effector; and
the single robotic drilling unit is configured to index the perforations relative to internal structure of the barrel structure such that all of the perforations are at a spaced distance relative to the internal structure, the internal structure being oriented perpendicular to the inner surface and located on a side of the inner surface opposite the single robotic drilling unit.

12. The drilling system of claim 11 , wherein:
the drill end effector is controlled to drill the perforations in a vertical row along a height of the barrel structure and/or in a horizontal row along a circumference of the barrel structure.

13. The drilling system of claim 12 , wherein:
the single robotic drilling unit has a vertical base axis; and
the drill end effector is rotatable about the vertical base axis to allow the drill end effector to drill another vertical row of perforations adjacent to a previously-drilled vertical row of perforations.

14. The drilling system of claim 11 , wherein:
the single robotic drilling unit is suspended over the barrel structure by an overhead fixture during drilling of the perforations.

15. The drilling system of claim 11 , wherein:
the barrel structure comprises multiple segments assembled together to form a closed shape.

16. A method of drilling perforations in a barrel structure, comprising the steps of:
supporting a barrel structure on a system base;
drilling, using a robotic drilling unit having a drill end effector positionable inside the barrel structure, a hole pattern of perforations into an inner surface of the barrel structure using the drill end effector; and
indexing, using the robotic drilling unit, the perforations relative to internal structure of the barrel structure such that all of the perforations are at a spaced distance relative to the internal structure, the internal structure being oriented perpendicular to the inner surface and located on a side of the inner surface opposite the robotic drilling unit.

17. The method of claim 16 , wherein the step of drilling the hole pattern of perforations comprises:
drilling, using the drill end effector, the perforations in a vertical row along a height of the barrel structure and/or in a horizontal row along a circumference of the barrel structure.

18. The method of claim 17 , wherein the step of drilling the hole pattern of perforations comprises:
rotating the drill end effector about vertical base axis of the robotic drilling unit to drill another vertical row of perforations adjacent to a previously-drilled vertical row of perforations.

19. The method of claim 16 , wherein the step of drilling the hole pattern of perforations comprises:
suspending the robotic drilling unit over the barrel structure by an overhead fixture when drilling the perforations.

20. The method of claim 16 , further comprising:
positioning a drilling unit base of the robotic drilling unit inside the barrel structure prior to drilling the hole pattern of perforations.

21. The drilling system of claim 1 , wherein:
the drill end effector has a vacuum attachment for removing debris generated during the drilling of the perforations.

22. The drilling system of claim 21 , wherein:
the vacuum attachment is configured to be positioned against the inner face sheet during the drilling of the perforations.

23. The drilling system of claim 1 , wherein:
the single robotic drilling unit is configured to form the perforations at a center-to-center positional tolerance of 0.010 inch or less.

24. The drilling system of claim 1 , wherein:
the drill end effector is configured to drive a drill bit at a feed rate of 20-60 inches per minute, and at rotational speeds of between approximately 20,000 to 40,000 rpm.

25. The drilling system of claim 1 , wherein:
the drill end effector is controlled to drill the perforations in a vertical row

Assignees

• Boeing Co

Inventors

• Zubin Claudio
• Gibbings Geoffrey
• Shewfelt Mathew J
• Simonovic Damjan
• Ferreira Antonio M
• Boonstra David
• Lauder Arnold J
• Gabriel Mark F

Classifications

• B23B39/20 Primary

  Setting work or tool carrier along a circular index line; Turret head drilling machines · CPC title

• B23B2270/16

  Constructions comprising three or more similar components · CPC title

• B64D2033/0286

  for turbofan engines · CPC title

• B64D33/02

  of combustion air intakes · CPC title

• Y10T408/03

  Processes · CPC title