Turbine engine casing and manufacturing method

1. A method for manufacturing a turbine engine casing, comprising the steps of:

manufacturing a plurality of angular sectors to be assembled to form a ring, said sectors comprising assembling strips arranged at their angular ends via which the sectors can be assembled, said strips extending all along said angular ends with a radial outer face parallel to the axis of the ring, at least some of the sectors being manufactured by casting and comprising on their surface attaching elements obtained in the casting step, a profile of a height of the assembling strips having minima and maxima at the same places as a profile of a thickness of the angular ends of the angular sectors, the length of the assembling strip along the axis of the ring being greater than the length of the angular ends of the angular sectors along the axis of the ring,

machining the outer face of the assembling strips and

assembling the sectors end-to-end so as to form a ring of the casing, the sectors being assembled by welding of the strips.

2. The method according to claim 1 , comprising the step of, after assembling the sectors:

machining the sectors, so as to form additional fastening elements on the surface of the sectors, and/or

machining, at least partly, the assembling strips.

3. The method according to claim 1 comprising the step consisting in hot forming of the ring.

4. The method according to claim 1 wherein the manufacturing step includes the titanium casting of the angular sectors.

5. The method according to claim 1 wherein the assembling strips, produced in the manufacturing step, have a constant width (L).

6. A turbine engine casing, comprising a ring composed of an assembly of a plurality of angular sectors, at least some of the sectors being manufactured from a single piece with attaching elements on their surface by a casting method, the sectors comprising at their angular ends assembling strips, said strips extending all along said angular ends with a radial outer face parallel to the axis of the ring, a profile of a height of the assembling strips having minima and maxima at the same places as a profile of a thickness of the angular ends of the angular sectors, the length of the assembling strip along the axis of the ring.

7. The method according to claim 1 , comprising the step, after assembling the sectors, removing the strips by machining.

8. The method according to claim 1 wherein the attaching elements comprise bosses, devises for fastening axes, flanges or arms.

9. The method according to claim 1 wherein the sectors comprise at least one rib.

10. The method according to claim 1 wherein a part of the sectors is manufactured using a rolling method.

11. The method according to claim 1 wherein a part of the sectors is manufactured using a rolling method of circular type.

12. The method according to claim 1 wherein the at least two angular sectors have the same angular extent.

13. The method according to claim 9 comprising the step, after assembling the sectors, at least one opening is manufactured in the ribs of the angular sectors.

14. The method according to claim 1 wherein the casing has a diameter greater than 1.50 meters.

15. The method according to claim 1 , comprising the step of, after assembling the sectors, machining the assembling strips so as to reduce the length of the assembling strip along the axis of the ring being to the length of the angular ends of the angular sectors along the axis of the ring.

16. The method according to claim 1 , in which before machining the outer face of the assembling strips, the height of the assembling strip is superior to the thickness of the angular ends of the angular sectors.

17. The casing according to claim 6 , wherein fastening elements on the surface of the sectors are machined.

18. The casing according to claim 6 , wherein the sectors are made of titanium.

19. The casing according to claim 6 , wherein:

the assembling strips have a constant width (L).

20. The casing according to claim 6 wherein the attaching elements comprise at least one of bosses, devises for fastening axes, flanges and arms.

21. The casing according to claim 6 wherein the angular sectors comprise at least one rib.

22. The casing according to claim 6 wherein a part of the angular sectors is manufactured using a rolling method.

23. The casing according to claim 6 wherein a part of the angular sectors is manufactured using a rolling method of circular type.

24. The casing according to claim 6 wherein the at least two angular sectors have the same angular extent.

25. The casing according to claim 21 wherein the angular sectors comprise at least one manufactured rib.

26. The casing according to claim 6 wherein the casing has a diameter greater than 1.50 meters.

27. A turbine engine comprising a fan and a casing according to claim 6 .

28. A method for manufacturing a turbine engine casing, comprising the steps of:

manufacturing a plurality of angular sectors to be assembled to form a ring, said sectors comprising assembling strips arranged at their angular ends via which the sectors can be assembled, said strips extending all along said angular ends with a radial outer face parallel to the axis of the ring, at least some of the sectors being manufactured by casting and comprising on their surface attaching elements obtained in the casting step, a profile of a height of the assembling strips having minima and maxima at the same places as a profile of a thickness of the angular ends of the angular sectors, the length of the assembling strip along the axis of the ring being greater than the length of the angular ends of the angular sectors along the axis of the ring

machining the outer face of the assembling strips and

assembling the sectors end-to-end so as to form a ring of the casing, the sectors being assembled by welding of the strips,

machining, at least partly, the assembling strips.