Lip skin sector and a method and apparatus for forming a lip skin sector

Patent metadata

Field	Value
Publication number	US-10875079-B2
Application number	US-201815959928-A
Country	US
Kind code	B2
Filing date	Apr 23, 2018
Priority date	Oct 28, 2015
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A method of forming a sector of an annular component such as an inlet cowl/lip skin of a nacelle for an aircraft engine. The method comprising the steps of clamping at least part of a blank along a clamping boundary in a retaining arrangement so as to leave a portion of the blank exposed within the clamping boundary. Moving a punch and/or retaining arrangement radially so that the punch comes in to contact with the exposed portion of the blank and through the main body of the exposed blank thereby drawing the blank onto an external surface of the punch forming the sector from the leading edge to the trailing edge. Activating cooperating forming arrangement for engaging the blank and drawing the blank over the punch forming the sector of the inlet cowl from the leading edge to the inlet edge, the method comprising using a second draw forming tooling arrangement for the cooperating forming arrangement.

First claim

What is claimed is:

1. An apparatus for forming a sector of an annular component comprising means for securely retaining at least a portion of a blank mountable thereon, the retaining means being adapted to leave a portion of the blank accessible, and a punch having an external surface contour shaped to correspond to the shape of all or a part of a profile of the sector of the annular component from a trailing edge to a leading edge and/or from the leading edge to an inlet edge, wherein the punch and/or the retaining means is capable of radial movement so that the punch is capable of coming into contact with the accessible portion of the blank for forming the blank from the trailing edge to the leading edge, the retaining means is adapted to allow controlled flow of the blank through the retaining means as the punch comes into contact with the blank for draw forming the blank across the punch, and the retaining means is adapted to form a clamping boundary enclosing the accessible portion of the blank to be formed by the punch;
the apparatus further comprises an arrangement of two separate draw forming tools, comprising:
a separate aft re-draw forming tool comprising a first arcuate gripping plate and a second arcuate gripping plate formed for gripping a bent section of the trailing edge of the blank there between; and
a leading edge re-draw tool.

2. The apparatus as claimed in claim 1 , wherein the retaining means comprises a blank holder and a die for retaining the blank there between with alignable cutouts respectively for receiving the punch.

3. The apparatus as claimed in claim 1 , wherein the leading edge re draw tool has a blank holder and a die for retaining the blank there between.

4. The apparatus as claimed in claim 1 , wherein a gap is provided between the aft re-draw forming tool and leading edge re-draw tool for receiving a second punch.

5. The apparatus as claimed in claim 1 , wherein the punch comes into contact with the blank for draw forming the blank across the punch to form a partially formed lip skin sector from the blank; and
an interior gripping face of at least one of the first arcuate gripping plate and the second arcuate gripping plate comprises an arcuate groove formed therein and the arcuate groove is formed for receiving the bent section of a trimmed portion of the partially formed lip skin sector.

6. The apparatus as claimed in claim 1 , wherein the punch comes into contact with the blank for draw forming the blank across the punch to form a partially formed lip skin sector from the blank; and
the leading edge re-draw tool comprises a pair of cooperating gripping ring sectors provided for draw forming the partially formed lip skin sector from the leading edge to the inlet edge of the lip skin sector.

7. The apparatus as claimed claim 6 , wherein one gripping ring sector of the pair of cooperating gripping ring sectors is an internal gripping ring sector having an external curved surface formed for engaging an internal surface of the partially formed lip skin sector.

8. The apparatus as claimed in claim 7 , wherein the other gripping ring sector of the pair of cooperating gripping ring sectors is an external gripping ring sector having an internal curved surface formed for engaging an external surface of the partially formed lip skin sector.

9. The apparatus as claimed in claim 8 , wherein the internal curved surface is formed for nesting engagement with an exterior curved surface of the internal gripping ring sector with clearance for the thickness of the partially formed lip skin sector.

10. The apparatus as claimed in claim 8 , wherein the leading edge of the external gripping ring sector is radiused to allow the partially formed lip skin sector to flow through and around the leading edge during a redraw forming process.

11. The apparatus as claimed in claim 1 , wherein the first arcuate gripping plate and the second arcuate gripping plate are configured to move in an axial direction for gripping the bent section of the trailing edge of the blank.

12. The apparatus as claimed in claim 1 , wherein a gripping face of the first arcuate gripping plate and a gripping face of the second arcuate gripping plate face in an axial direction.

13. A method of forming a sector of an annular component, the method comprising the steps of:
clamping at least part of a blank along a clamping boundary in a retaining means so as to leave a portion of the blank exposed within the clamping boundary;
moving a punch and/or the retaining means radially so that the punch comes in to contact with the exposed portion of the blank and through a main body of the exposed portion of the blank thereby drawing the blank onto an external surface of the punch forming the sector from a leading edge of the sector to a trailing edge of the sector, thereby forming a partially formed lip skin sector;
trimming a trailing portion of the partially formed lip skin sector, leaving a bent section at the trailing edge;
placing the trimmed partially formed lip skin sector into a second draw forming tooling arrangement, the second draw forming tooling arrangement comprising a separate aft re-draw forming tool and a leading edge re-draw tool;
clamping the bent section of the trimmed partially formed lip skin sector between a first arcuate gripping plate of the separate aft re-draw forming tool and a second arcuate gripping plate of the separate aft re-draw forming tool; and
activating the second draw forming tooling arrangement for engaging the trimmed partially formed sector and drawing the trimmed partially formed sector over a second punch forming the sector from the leading edge to an inlet edge.

14. The method as claimed in claim 13 , wherein the method further comprises applying a draw load between a blank holder and a die of the leading edge re-draw tool.

15. The method as claimed in claim 14 , wherein the method further comprises:
placing a draw load on the aft re-draw forming tool; and
fixing a position of the two arcuate plates of the aft re-draw forming tool while applying the draw load to the blank holder and the die of the leading edge re-draw tool while the blank holder and the die of the leading edge re-draw tool are forced into the second punch by a predetermined draw distance under a predetermined gripping force load.

16. The method as claimed in claim 15 , wherein the method further comprises applying a predetermined stretch load to the blank holder and the die of the leading edge re-draw tool once the predetermined draw distance has been reached for reducing or eliminating the draw of the trimmed partially formed lip skin sector between the blank holder and the die of the leading edge re-draw tool.

17. The method as claimed in claim 15 , wherein the method further comprising placing a predetermined stretch load on the aft re-draw forming tool.

18. The method as claimed in claim 15 , wherein the method further comprising:
applying a predetermined stretch load to the blank holder and the die of the leading edge re-draw tool once the predetermined draw distance has been reached for reducing or eliminating the draw of the trimmed partially formed lip skin sector between the blank holder and the die of the leading edge re-draw tool;
placing a predetermined stretch load on the aft re-draw forming tool; and simultaneously moving the two arcuate plates of the aft re-draw forming tool a predetermined stretch distance while the stretch load is applied to the blank holder and the die of the leading edge re-draw tool.

19. The method as claimed

Assignees

• Rohr Inc

Inventors

• Ludlow Michael
• Mccracken David

Classifications

• B21D53/92 Primary

  other parts for aircraft · CPC title

• B21D25/02

  by pulling over a die · CPC title