METHOD OF MANUFACTURING A COMPOSITE TURBOMACHINE BLADE, AND A BLADE OBTAINED BY THE METHOD

• US 20070092379A1
• Filed: 10/18/2006
• Published: 04/26/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Safran Aircraft Engine Company
• Original Assignee: Snecma (Safran SA)
• Inventors: Mahieu, Jean-Noel, Dambrine, Bruno, Leveque, Stephane, COUPE, Dominique
• Granted Patent: US 7,581,932 B2
• Time in Patent Office: Days
• US Class Current: 416/241.00R
• CPC Class Codes: B29B 11/16 comprising fillers or reinforcement non-woven fabrics per se D04H1/00, D04H3/00
• CPC Class Codes: B29C 70/24 oriented in at least three directions forming a three dimensional structure
• CPC Class Codes: B29C 70/461 Rigid movable compressing mould parts acting independently from opening or closing action of the main mould
• CPC Class Codes: B29C 70/48 and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM] , e.g. by vacuum
• CPC Class Codes: B29C 70/541 Positioning reinforcements in a mould, e.g. using clamping means for the reinforcement positioning inserts in moulds B29C33/12; lay-up on a mould B29C70/30
• CPC Class Codes: B29C 70/543 Fixing the position or configuration of fibrous reinforcements before or during moulding for non-woven fabrics D04H3/08
• CPC Class Codes: B29C 70/545 Perforating, cutting or machining during or after moulding
• CPC Class Codes: B29L 2031/08 Blades for rotors, stators, fans, turbines or the like, e.g. screw propellers
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F05D 2240/303 related to the leading edge of a rotor blade

Abstract

The invention relates to a method of manufacturing a composite turbomachine blade, the method comprising the following steps: a) making a preform by three-dimensionally weaving yarns including tracer yarns disposed at least at the surface of the preform; b) cutting out said preform so as to leave intact a series of tracer yarns situated along a reference face of the preform; c) pre-deforming said cut-out preform; d) compacting and stiffening said pre-deformed preform; e) providing an injection mold in which said stiffened preform is placed; f) heating said injection mold; g) injecting a binder into said injection mold, the binder comprising a thermosettable resin; and h) extracting from the mold a composite molded part presenting substantially the shape and the dimensions of said blade. The invention is applicable to a making fan blade.

Claims

1. A method of manufacturing a composite turbomachine blade, the method comprising the following steps:

a) making a preform by three-dimensional weaving of yarns, said preform comprising both the airfoil and the root of the blade, the yarns including tracer yarns that are visually identifiable and that are disposed at least on the surface of the preform;

b) cutting out said preform while leaving intact a series of tracer yarns situated along a reference face of the preform, thereby providing a cut-out preform suitable for taking the shape and the dimensions of portions constituting the blade;

c) pre-deforming said cut-out preform so as to provide a pre-deformed preform;

d) compacting and stiffening said pre-deformed preform;

e) providing an injection mold in which said stiffened preform is placed;

f) injecting into said injection mold a binder comprising a thermosettable resin so as to impregnate the entire stiffened pre-deformed preform and maintain the relative disposition between the yarns of the preform;

g) heating said injection mold; and

h) extracting from the mold a composite molded part presenting substantially the shape and the dimensions of said blade.

2. A method according to claim 1, wherein the tracer yarns are of different nature from that of the other yarns.

3. A method according to claim 1, wherein, during step c), said pre-deformation is performed by placing the cut-out preform in a shaping mold.

4. A method according to claim 3, wherein the shaping mold puts the cut-out preform in a configuration that deforms it in rotation about an axis parallel to its main direction.

5. A method according to claim 4, wherein, during step c), prior to placing the cut-out preform in the shaping mold, preliminary pre-deformation is performed that consists in applying shear in a direction parallel to the main direction of the cut-out preform, while maintaining the cut-out preform in a plane.

6. A method according to claim 5, wherein, during step d), before or after stiffening, the following sub-steps are performed:

d1) supercompacting the pre-deformed preform at the location of the leading edge; and

d2) mounting a metal, leading edge protector element on the pre-deformed preform at the location of the leading edge, the protector element presenting two flanges for receiving a portion of the pressure-side and suction-side walls.

7. A method according to claim 6, wherein, during step d2), said protector element is placed in a mounting device suitable for splaying apart said flanges of said protector element, and then said mounting device is placed on the pre-deformed preform in such a manner that the two flanges of said protector element are fitted onto the supercompacted leading edge of the pre-deformed preform, and then said flanges are released.

8. A method according to claim 6, wherein, prior to step d2), a protective film is secured on the pre-deformed preform over a portion of the outside surface of the pressure-side wall that includes the leading edge.

9. A method according to claim 8, wherein the protective film is made of polyurethane.

10. A method according to claim 8, wherein an interface element is interposed between the protective film and the pre-deformed preform, the interface element forming extra thickness on the yarns of the preform.

11. A method according to claim 1, wherein, during step e), at least one spacer is also placed in said injection mold against the surface of the stiffened preform that is to form the bottom of the blade root.

12. A method according to claim 11, wherein, during steps f) and g), said spacer is maintained under constant pressure against the surface of the stiffened preform that is to form the bottom of the blade root.

13. A fan blade obtained by the method of claim 1.

14. A blade according to claim 13, wherein said preform is made up of warp yarns and weft yarns, the direction of the warp yarns forming the longitudinal direction of the preform, wherein said preform comprises at least a first portion made with a first weave forming the airfoil of the blade, and a second portion made with a second weave forming the root of the blade, and wherein the first and second portions are united by a transition zone in which the first weave is modified progressively to become the second weave, thereby obtaining a reduction at least in the thickness of the blade between the second portion and the first portion.

15. A blade according to claim 14, wherein the yarns belong to the group constituted by:

carbon fibers;

glass fibers;

silica fibers;

silicon carbide fibers;

alumina fibers;

aramid fibers; and

aromatic polyamide fibers.

16. A blade according to claim 15, wherein the warp yarns and the weft yarns are carbon fibers, and wherein the tracer yarns are glass fibers.