Method for producing a part made of composite material, and so obtained composite part

Abstract

A method for producing a part made of composite material includes adding a thermoplastic or thermosetting matrix around a preform of a reinforcing fiber mesh made by filament winding around the spurs or the like of a frame. There is winding in addition to the fibers on one or several reels within the matrix, the axes of the spurs or the like and those of the one or more reels having different orientations, so as to provide the mesh of fibers with a three-dimensional shape.

Claims

1. A method for composite material, the method comprising the steps of: assembling a plurality of reels, each reel of said plurality of reels being comprised of a shaft along an axis so as to define a reel plane perpendicular to said axis and a plurality of lateral flanges at each end of said shaft, each reel of said plurality of reels having one side and an opposite side; winding a plurality of initial fibers around a respective shaft of a corresponding reel of said plurality of reels between a respective plurality of lateral flanges of said corresponding reel of said plurality of reels under tension so as to form an initial wind with a knot with initial resistance, an initial reel plane, and an initial rigidity; winding a plurality of bar fibers from said initial wind to another reel so as to form a bar under tension with bar resistance, a bar reel plane, and a bar rigidity after said knot, said bar reel plane being different from said initial reel plane, said bar resistance being different from said initial resistance, said bar rigidity being different from said initial rigidity, said plurality of bar fibers being comprised of a first bar fiber on said one side of said corresponding reel and a second bar fiber on said opposite side of said corresponding reel; winding a plurality of consolidation fibers around said respective shaft of said corresponding reel of said plurality of reels so as form a consolidation wind, after the initial wind and after winding said first bar fiber of said bar, said initial wind, said bar, and said consolidation wind forming a reinforcing-fiber mesh; and adding a matrix around said reinforcing-fiber mesh so as to produce part with a three-dimensional shape based on said initial reel plane and said bar reel plane.

2. The method for composite material, according to claim 1, wherein the step of winding said plurality of bar fibers comprises the steps of: passing said first bar fiber on said one side of the said corresponding reel to said another reel; and passing said second bar fiber from said another reel to said opposite side of the said corresponding reel.

3. The method for composite material, according to claim 2, wherein initial tension between said corresponding reel and said another reel is maintained by said knot with said initial resistance and said initial rigidity.

4. The method for composite material, according to claim 1, wherein the step of winding said plurality of initial fibers around said respective shaft of said corresponding reel of said plurality of reels between said respective plurality of lateral flanges of said corresponding reel of said plurality of reels so as to form an initial wind is comprised of: winding said plurality of initial fibers completely around said respective shaft of said corresponding reel of said plurality of reels between said respective plurality of lateral flanges of said corresponding reel of said plurality of reels.

5. The method for composite material, according to claim 1, wherein in the step of adding said matrix is comprised of one of a group consisting of: soaking the mesh, spraying the mesh, and overmolding the mesh.

6. The method for composite material, according to claim 1, wherein the step of winding said plurality of consolidation fibers around said respective shaft of said corresponding reel of said plurality of reels is after winding said second bar fiber of said bar.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) In the attached drawing:

(2) FIGS. 1 and 2 show schematic views of a planar connecting rod during its manufacturing by the method according to the invention.

(3) FIG. 3 shows a schematic view of a variant of the same connecting rod.

(4) FIG. 4 shows a partial schematic and cross-sectional view of a portion of the same connecting rod.

(5) FIGS. 5, 6, 7 and 8 show schematic perspective views of parts made of composite material manufactured according to the method.

DETAILED DESCRIPTION OF THE INVENTION

(6) When referring to FIGS. 1 and 2, we can see a planar connecting rod 1 made of composite material manufactured by implementing the method according to the invention.

(7) More specifically, FIG. 1 shows a first step of manufacturing a mesh structure 10 of reinforcing fibers F, made by filament winding.

(8) The fiber F, which may consist, without limitation, of strands, ribbons or cords of reinforcing fibers, is wound between two pulleys 2 and 3 for forming the two eyecups of the connecting rod 1, and carried by a frame, not shown.

(9) According to the invention, the frame also carries reels 4, or intermediate pulleys, arranged between the pulleys 2 and 3, and on which the fiber F is also wound.

(10) These reels 4, or intermediate pulleys, permit to create, between each pair of reels 4, bars 5 that form the mesh structure 10.

(11) In FIG. 2, we can see a next step of the method, which consists in molding on the mesh structure 10 a thermosetting or thermoplastic matrix M, as the case may be, the reels 4 and the bars 5 being embedded in this matrix M.

(12) When referring now to FIG. 3, we can see that the method according to the invention allows multiple possibilities of making the mesh structure 10, especially when the reels 4 have a determined diameter.

(13) It is thus possible, when making a change in direction of the winding on a spool 4, to pass on one side or the other of the latter, to stretch fibers F obliquely in a bar 5.

(14) The reels 4 permit to vary the direct or crossed, single or multiple reels, so as to permit an optimization of the fiber mesh.

(15) It should be noted that the molding of the matrix M is carried out in a mold, not shown, and that in the latter may be arranged, before molding, several preforms each comprised of a mesh structure 10.

(16) It should also be noted that in FIGS. 1, 2 and 3 the reels 4 may, according to the invention, as cannot be seen in a top view, not be in the same plane, so that the bars 5 are inclined in planes (reel plane 40B) that are not perpendicular to the axes 40A of the reels 4.

(17) When referring to FIG. 4, we can see a reel 4, or intermediate pulley. This reel 4 comprises, in this non-restrictive embodiment, a shaft 40 and two lateral flanges 41.

(18) It will be understood that such a reel 4 permits the fibers F to extend in planes (reel plane 40B) that are not perpendicular to the axis of the shaft 40.

(19) According to the invention, the winding of the fiber F (initial fibers F1, bar fibers F2 (a first bar fiber F2a, a second bar fiber F2b), and consolidation fibers F3) at the level of such a reel 4 is divided into several phases. In a first step, an initial winding or initial wind 42 is performed around the shaft 40 between the flanges 41, in order to provide the knot 44 to be formed with the resistance and the minimum rigidity, and then a winding is performed to another reel 4 for creating the bars 5. Then, windings for a final or consolidation wind 43 around the shaft 40 and between the fibers F that form the bars 5 are performed during and/or after the creation of the windings for creating the bars 5.

(20) The aim of these windings is to block the deformation in compression in the wound area, but also to reduce, according to the need, the length of the bars 5 prone to buckling.

(21) When referring to FIGS. 5, 6, 7 and 8, we can see composite parts 6, 7, 8 and 9, respectively, made by implementing the method according to the invention.

(22) It can be observed that the winding of the fibers can be made between two reels 4 with non-parallel axes. The so obtained winding is globally twisted while complying with the straightness of the beams 50 of fibers forming the bars 5.

(23) This twisting associated with the choice of the diameter of the reels 4 permits to create a three-dimensional fiberizing potentially having out-of-plane resistance.

(24) It should be noted that some reels 4 of these parts 6, 7, 8 and 9 constitute interface forms.

(25) It is possible to create a three-dimensional fiber mesh suitable for optimizing the fiberizing of a volume part having a mechanical strength during phases of compression of the bars 5 forming the mesh 10.