Woven preform for producing a circumferential or toroidal reinforcement having an omega-shaped cross-section
A method of manufacturing a preform including a core and a sole includes contour weaving the preform on a lap roller having a groove or an outgrowth allowing shape weaving of the core and the sole of the preform. At least one portion of the core and at least one portion of the sole include weft yarns which cross each other on common warp yarns.
1. A method for manufacturing a preform comprising a core and a sole, the method comprising:
contour weaving the preform on a lap roller having a groove or an outgrowth allowing shape weaving of the core and the sole of the preform,
wherein at least one portion of said core and at least one portion of said sole comprise weft yarns which cross each other on common warp yarns, and
wherein weft yarns of said core form an angle different from 90° with at least one portion of warp yarns of said core.
2. The manufacturing method according to claim 1 , further comprising tightening sides of said preform in order to reduce a width of the preform, while increasing a winding diameter of said core and said sole.
3. The manufacturing method according to claim 1 , further comprising cutting the sole at an output of a shuttle loom in order to form a central slot so that the sole is formed of two portions separated from each other.
4. The manufacturing method according to claim 1 , further comprising:
forming at least two additional lateral warp sheets unbound from weft yarns of the core of the preform;
unpleating lateral portions of the core to a center of the preform so that the sole is formed of two portions separated from each other.
5. The manufacturing method according to claim 1 , wherein the step of contour weaving includes:
binding warp yarns of lateral portions of the sole to warp yarns of a central portion of the sole via weft yarns of the sole; and
binding the warp yarns of the lateral portions of the sole to the warp yarns of a central portion of the core via weft yarns of the core.
6. The manufacturing method according to claim 1 , wherein the step of contour weaving includes:
binding a warp sheet of lateral portions of the sole to warp yarns of a central portion of the core via at least a portion of the weft yarns of the sole; and
binding warp sheets of lateral portions of the sole to warp yarns of a central portion of the core via another portion of the weft yarns of the sole.
7. The manufacturing method according to claim 1 , wherein the step of contour weaving includes:
binding at least one warp sheet of lateral portions of the sole to at least one warp sheet of central portions of the sole via at least a portion of the weft yarns of the sole; and
binding warp sheets of the sole to warp yarns of a central portion of the core via another portion of weft yarns of the sole.
8. The manufacturing method according to claim 1 , wherein the step of contour weaving includes forming the core to comprise a superposition of fabrics having warp sheets that are at least partially bound therebetween.
9. The manufacturing method according to claim 1 , wherein step of contour weaving includes forming the sole to comprise a superposition of fabrics having warp sheets that are at least partially bound therebetween.
10. The manufacturing method according to claim 1 , wherein the step of contour weaving includes forming the core to comprise a superposition of fabrics attached to each other by interlocking of correspondingly shaped fabrics.
11. The manufacturing method according to claim 1 , wherein the step of contour weaving includes forming the sole of two portions separated from each other.
12. The manufacturing method according to claim 11 , wherein the two portions are separated from each other so as to define a slot.
13. The manufacturing method according to claim 1 , wherein the step of contour weaving includes forming the sole of two portions that partially overlap.
14. The manufacturing method according to claim 1 , wherein the core is located in a concave portion of said preform.
15. The manufacturing method according to claim 1 , wherein wherein the core is located on a convex portion of said preform.
16. The manufacturing method according to claim 1 , further comprising draping at least one of the sole and the core to form a superposition of fabrics attached to each other.
17. The manufacturing method according to claim 16 , wherein at least a portion of the fabrics and the preform are bound by stitchings.
18. The manufacturing method according to claim 1 , further comprising impregnating the preform with resin and baking the preform to polymerize the resin.
19. The manufacturing method according to claim 1 , wherein the core and sole define an omega-shaped cross-section.