• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a fibrous reinforcement for producing an elongated mechanical part (10) made of composite material comprising at one end at least one yoke (14) intended to receive an axis for making a pivot connection with another part, the reinforcement fiber material being made from a central fibrous structure (106; 106 ') for forming a core which is obtained by three-dimensional weaving, of a peripheral fibrous structure (16; 16') for forming a belt which surrounds the structure at least one free cylindrical space, and at least one annular fibrous structure (112; 112 '; 112 ") for forming a ring which is formed at the center of the room. inside the free space between the central structure and the peripheral structure.
    公开号:FR3017819A1
    申请号:FR1451489
    申请日:2014-02-25
    公开日:2015-08-28
    发明作者:Sylvain Leclercq；Bruno Jacques Gerard Dambrine；Dominique Marie Christian Coupe
    申请人:Messier Bugatti Dowty SA；Safran SA；SNECMA SAS；
    IPC主号:
    专利说明:

    [0001] BACKGROUND OF THE INVENTION The present invention relates to the general field of producing elongated mechanical parts of composite material which comprise at least one of their ends a clevis intended to receive an axis. to make a pivot connection with another part and which are stressed in tension and in compression. A non-limiting example of application of the invention is that of the realization of struts for landing gear. A strut of a landing gear serves to take up the lateral forces exerted on the train and to maintain it deployed after contact with the ground. Typically, a strut consists of two arms that are articulated to each other and to other parts of the landing gear at their ends, via pivot links. Such mechanical parts are subjected in operation to significant mechanical forces, mainly in compression and in tension, oriented along the longitudinal axis of the part (that is to say the axis passing through the two ends of the part ). These parts are generally made of alloys of steel, aluminum or titanium. In order to reduce the mass of these mechanical parts, it has been proposed to make them out of composite material. However, the realization of these parts made of composite material poses a number of problems. In particular, the width and the height of these screeds with regard to the matting limitations generally lead to over-sizing for the metal parts of interfaces with the other parts of the landing gear. In addition, these composite material parts have low resistance to impact and a high risk of delamination, that is to say, separation of the fiber layers, related to the repeated forces to which the part is subjected. Finally, the manufacturing costs of these parts are high. To meet these requirements, the document EP 1,736,674 proposed to make these mechanical parts made of composite material from a central fiber preform and a peripheral fiber preform obtained by three-dimensional weaving, the peripheral preform surrounding the central preform so that to allow to substitute at the ends of the part, between the two preforms, two free spaces dedicated to the articulation of the other parts. Metal inserts are housed in these spaces. This mechanical part thus has a gain in matting for tensile forces on the yoke.
    [0002] OBJECT AND SUMMARY OF THE INVENTION The object of the present invention is to propose a mechanical part made of composite material making it possible, on the one hand, to also obtain a gain in matting for the efforts in compression as well as in tension on the screed, and on the other hand, to push the discontinuity of matter out of an over-stress zone. According to the invention, this object is achieved by means of a fibrous reinforcement for the production of an elongate mechanical part made of composite material comprising at one end at least one yoke intended to receive an axis for making a pivot connection with another part, the fibrous reinforcement being made from a central fibrous structure for forming a core which is obtained by three-dimensional weaving, of a peripheral fibrous structure intended to form a belt which surrounds the central structure so as to provide at the level of the screed at least one free cylindrical space, and at least one annular fiber structure for forming a ring which is formed within the free space between the central structure and the peripheral structure. The fibrous reinforcement according to the invention is remarkable in that the presence of a composite material ring which is housed inside the free space provided between the central structure and the peripheral structure makes it possible to significantly repel the rupture in matting, in particular for the efforts in compression as well as in traction on the screed. This results in a gain in mass of the part and avoids over-dimensioning the interface parts while facilitating its integration 30 with a smaller footprint. According to one embodiment, the annular structure forms one and the same structure with the central structure. According to another embodiment, the annular structure forms a single structure with the peripheral structure. In this case, the peripheral structure and the annular structure can be obtained by three-dimensional weaving of a fibrous blank in one piece with a main portion having a strip shape extending in a direction corresponding to the longitudinal direction of the core to be manufactured, and two secondary parts each connected to the main part by a debonding zone to form two longitudinal tongues intended to be folded towards one another to form a ring. The two tabs of the fibrous blank may each have a truncated portion in the longitudinal direction so as to allow recovery between the tongues when they are folded towards one another.
    [0003] In addition, the fibrous blank of the peripheral structure and the annular structure may comprise a plurality of layers of warp yarns extending in the lengthwise direction of the web and tongues and interconnected by weft yarns. . According to yet another embodiment, the annular structure forms a structure distinct from the central structure and the peripheral structure. In this case, the annular structure can be obtained by three-dimensional weaving of a fibrous blank in the form of a band which is intended to be wound to form a ring. Alternatively, the annular structure can be obtained by braiding.
    [0004] The invention also relates to an elongated mechanical part made of composite material comprising a fibrous reinforcement. This mechanical part may constitute a lever of a strut for landing gear.
    [0005] BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will emerge from the description given below, with reference to the accompanying drawings which illustrate embodiments having no limiting character. In the figures: - Figure 1 is a schematic perspective view of an example of landing gear strut; FIG. 2 represents an example of a mechanical part according to the invention; FIGS. 3A to 3C various stages of obtaining the mechanical part of FIG. 2 according to one embodiment of the invention; FIGS. 4A and 4B show different stages of obtaining the mechanical part of FIG. 2 according to another embodiment of the invention; and FIGS. 5A to 5C show different stages of obtaining the mechanical part of FIG. 2 according to yet another embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION The invention applies to the production of any elongated mechanical part made of composite material comprising at one end at least one yoke intended to receive an axis in order to make a pivot connection with another part. An example of a non-limiting application is that of the embodiment of a landing gear strut such as that shown in FIG. 1. Typically, such a strut 2 serves to take up the lateral forces exerted on the train and to maintaining it deployed comprises an upper lever 4a and a lower lever 4b which are each in the form of an elongated mechanical part. These levers 4a, 4b are hinged to each other and to other parts of the landing gear at their respective ends, by means of hinge pins symbolized in phantom in Figure 1. Figure 2 is an example of a mechanical part 10 which can serve as a lower lever or upper lever of a strut such as that illustrated in Figure 1. The part 10 comprises an elongate body 12 which ends at each longitudinal end by a double clevis 14 for receiving an axis for making a pivot connection with another part. These double clevises 14 are each in the form of a U, each branch comprising an orifice for the passage of an axis for the pivot connection. Of course, in other application examples not shown, the part could have at each end only simple clevises, or a double yoke at one end and a single yoke at the other end, or a single or double clevis at only one of its ends, etc. This part is made entirely of composite material from a fiber reinforcement densified by a matrix. The fibrous reinforcement is made from several fibrous structures, especially carbon fibers, which will be described later. Once shaped and dried, these fibrous structures are placed in an injection mold. Deposition of the matrix in the fibrous structures is achieved by keeping them in the mold at least until stiffening (or consolidation) structures. The matrix is of a nature chosen according to the intended application, for example an organic matrix obtained in particular from a polymer matrix precursor resin such as an epoxy, bismaleimide or polyimide resin, or a carbon matrix or a matrix ceramic. In the case of an organic matrix, the fibrous structures are impregnated with a composition containing the matrix precursor resin, before conformation in a tool, or after conformation, the impregnation being in the latter case carried out for example by infusion or by a RTM process (nResin Transfer Molding) In the case of a carbon or ceramic matrix, the densification may be carried out by chemical vapor infiltration, or CVI ("Chemical Vapor Infiltration") or by impregnation with a liquid composition containing a precursor resin of carbon or ceramic and heat treatment of pyrolysis or ceramization of the precursor, these methods being well known per se According to the invention, the fibrous reinforcement intended, after densification by a matrix, to form the workpiece 10 is made from a central fibrous structure obtained by three-dimensional weaving to form the core of the piece, a peripheral fibrous structure obtained by three-dimensional weaving to form a belt surrounding the core so as to provide at the yoke of the part two free cylindrical spaces, and two annular fiber structures for making rings which are formed inside open spaces between the soul and the belt. FIGS. 3A to 3C show, according to a first embodiment of the invention, different steps for obtaining such a fiber reinforcement. In this first embodiment, the peripheral fibrous structure for producing the belt is obtained by three-dimensional weaving from the fiber blank shown in FIG. 3A. This fibrous blank is in the form of a web 100 comprising a plurality of warp thread layers extending in the lengthwise direction of the web and interconnected by weft threads (warp and weft directions). are shown in Figure 3A). Apertures 102 of oblong shape, oriented in the longitudinal direction and traversing in the direction of the thickness, are made in the strip. Such openings are for example made by cutting with water jet. The band 100 thus obtained is then bent along the arrows F (FIG. 3B) so as to join its free ends 104 and form a loop. These ends 104 are then joined to each other, for example by sewing, gluing or any other suitable technique. Once the band 100 is curved, the peripheral structure 16 shown in FIG. 3B is obtained with the openings 102 located at opposite ends of the loop. Reference can be made to EP 1,736,674 which describes the production of such a peripheral structure. In an alternative embodiment of the peripheral structure not shown, it could be obtained by winding several turns of the same fibrous web to form a loop like that of Figure 3B. The central fibrous structure 106 for forming the core of the part is obtained by three-dimensional weaving of the fiber blank shown in FIG. 3C. This fibrous blank in one piece is in the form of a beam section, for example H (or other, for example 0, S, etc.), with two longitudinal portions 108 30 connected by a transverse part 110. At each of their ends, the two longitudinal portions 108 of the central structure each end with an annular structure 112 provided with an orifice 114. These annular structures are intended to form composite material rings for the passage 35 an axis of the pivot connection. The annular structures 112 and the central structure 106 here form one and the same fibrous structure obtained by three-dimensional weaving. Once the peripheral and central fibrous structures 106 are made and shaped as previously described, they are nested one inside the other by positioning the peripheral structure around the central structure. In particular, in this position, the peripheral structure 16 accommodates with the central structure 106, at the ends thereof, cylindrical spaces which are filled by the annular structures 112. The structures are then assembled together by stitching, collage or any other appropriate technique. A fibrous reinforcement is thus obtained which, after densification by a matrix, becomes the part 10 represented in FIG. 2. In particular, this fibrous reinforcement comprises, at the yokes 14, rings (formed by the annular structures 112 of the structure central) of composite material, which allows to substantially push the mode of failure in matting efforts of the piece. FIGS. 4A and 4B show, according to a second embodiment of the invention, different steps for obtaining the same fibrous reinforcement. This second embodiment differs from that previously described in that the annular structures for forming the rings at the yokes of the room are separate structures of the central structure and the peripheral structure. The central structure for forming the core of the part is obtained by three-dimensional weaving from the fibrous blank 106 'shown in FIG. 4A. This fibrous blank is close to that shown in FIG. 3B, especially in that it is in the form of a section beam, for example H (or other, for example 30, S, etc.). ), with two longitudinal parts 108 'connected by a transverse part 110'. Unlike the first embodiment, this beam is devoid, at its longitudinal ends, of annular structures for forming the rings. Reference can be made to EP 1,736,674 which describes the production of such a central structure. As for the peripheral fibrous structure 16, it is identical to that shown in FIG. 3A, namely that it is obtained by three-dimensional weaving from a fibrous blank in the form of a strip in which apertures 102 are formed which is bent to form a loop (see Figure 4B). The annular structures 112 'intended to form the rings for the passage of an axis of the pivot connection are shown in FIG. 4B. They can each be obtained by three-dimensional weaving of a fibrous blank in the form of a band which is then curved into a ring to form a ring. In this case, the fibrous blank of each annular structure 112 'comprises a plurality of warp son layers extending in the lengthwise direction of the web and interconnected by weft threads. When bent in the form of a ring, the warp threads 15 thus extend in a circumferential direction, while the weft threads extend in the direction of the thickness of the ring. Alternatively, the annular structures 112 'can be obtained each by braiding. Once the peripheral structure 16, the central structure 106 'and the annular structures 112' made and shaped as described above, they are interlocked with one another by positioning the peripheral structure around the central structure. In particular, in this position, the peripheral structure 16 accommodates with the central structure 106 ', at the ends thereof, cylindrical spaces 114 in which are positioned the annular structures 112'. The structures are then assembled together by sewing, gluing or any other appropriate technique. A fibrous reinforcement is thus obtained which, after densification by a matrix, becomes the part 10 represented in FIG. 2. FIGS. 5A to 5C show, according to a third embodiment of the invention, different steps for obtaining the same fibrous reinforcement. In this third embodiment, the annular structures for forming the rings at the yokes of the part form one and the same structure with the peripheral structure intended to produce the core of the part. More specifically, the peripheral fibrous structure and the two annular structures are obtained by three-dimensional weaving of the one-piece fiber blank 200 shown in Figure 5A. This fibrous blank 200 consists of a main portion 5 having a strip shape 202 which extends in a direction corresponding to the longitudinal direction of the core to be manufactured. Openings 204 of oblong shape, oriented in the direction of length and traversing in the direction of the thickness, are practiced in this band. On the other hand, at the strip portions 206 that line each opening 204, the fiber blank also includes two secondary portions 208 each bonded to the web 202 by a debonding zone 210 and forming longitudinal tongues. This fibrous blank 200 is made in three-dimensional weave in one piece by a plurality of layers of warp yarns which extend in the length direction of the web 202 and which are interconnected by weft yarns. The warp and weft directions are shown in FIG. 5A. The band 202 with the tabs 208 is bent along the arrows F 'so as to join its free ends 212 and form a loop. These ends 212 are then joined to each other and optionally reinforced by sewing, gluing or any other appropriate technique. During this operation, the tongues 208 of the fibrous blank bend toward each other around a suitable tool 300 to form two annular structures 112 "at each aperture 204 (FIG. 5B). In particular, the free ends of these tongues are joined to one another by sewing, gluing or any other suitable technique.When wound in the form of annular structures 112 ", the warp threads of the tongues 208 thus extend in a circumferential direction, while the weft threads extend in the direction of the thickness of the rings. In the example shown in FIGS. 5A to 5C, the two tongues 208 of the fibrous blank each have a portion 35 truncated in the longitudinal direction so as to allow partial overlap between the tongues when they are folded back one towards the other.
    [0006] This overlap zone between the tongues 208 may extend by varying the degression of the slopes which will be chosen and adapted to the stressing imnensionement. Of course, it is possible to imagine that the free ends of the tabs of the fiber blank of the peripheral structure do not overlap and meet edge to edge. In this case, these free ends will also be assembled together by any appropriate technique. After such shaping, the peripheral structure 16 'shown in FIG. 5C is obtained with the apertures 204 located at opposite ends of the loop and two rings formed by the tongues 208 at the strip portions 206 which line each opening 204. As for the central structure 106 'intended to form the core of the part, it is identical to that shown in FIG. 4A, namely that it is obtained by three-dimensional weaving and that it is presented under form of a beam section, for example H (or other, for example 0, S, etc.), with two longitudinal portions 108 'connected by a transverse portion 110'.
    [0007] Once the peripheral structure 16 'and the central structure 106' are produced and shaped as described above, they are nested in each other by positioning the peripheral structure around the central structure. In particular, in this position, the peripheral structure 16 'accommodates with the central structure 106' at the ends thereof, cylindrical spaces in which are positioned the rings formed by the annular structures 112 'of the peripheral structure. The structures are then assembled together by sewing, gluing or any other appropriate technique.
    [0008] A fibrous reinforcement is thus obtained which, after densification by a matrix, becomes the part 10 represented in FIG.
    权利要求:
    Claims (12)
    [0001]
    REVENDICATIONS1. Fibrous reinforcement for the production of an elongate mechanical part (10) made of composite material comprising at one end at least one yoke (14) intended to receive an axis for making a pivot connection with another part, the fibrous reinforcement being made from a central fibrous structure (106; 106 ') for forming a core which is obtained by three-dimensional weaving; a peripheral fibrous structure (16; 16 ') for forming a belt which surrounds the central structure so as to provide at least one free cylindrical space at the end of the workpiece; and at least one annular fibrous structure (112; 112 '; 112 ") for forming a ring which is formed within the free space formed between the central structure and the peripheral structure.
    [0002]
    The fibrous reinforcement of claim 1, wherein the annular structure (112) forms a single structure with the central structure (106). 20
    [0003]
    The fibrous reinforcement of claim 1, wherein the annular structure (112 ") forms a single structure with the peripheral structure (16 ').
    [0004]
    A fibrous reinforcement according to claim 3, wherein the peripheral structure and the annular structure is obtained by three-dimensional weaving of a fibrous blank (200) in one piece with: a main portion (202) having a strip shape; extending in a direction corresponding to the longitudinal direction 30 of the core to be manufactured, and two secondary parts (208) each connected to the main part by a debonding zone (210) to form two longitudinal tongues intended to be folded down the towards each other to form a ring. 35 301 7 8 1 9 12
    [0005]
    5. A fibrous reinforcement according to claim 4, wherein the two tongues of the fibrous blank each have a portion truncated in the longitudinal direction so as to allow recovery between the tongues when they are folded towards one another. 5
    [0006]
    The fiber reinforcement according to one of claims 4 and 5, wherein the fibrous blank of the peripheral structure and the annular structure comprises a plurality of layers of warp threads extending in the lengthwise direction of the web. and tongues and interconnected by weft threads.
    [0007]
    The fibrous reinforcement of claim 1, wherein the annular structure (112 ') forms a structure distinct from the central structure (106') and the peripheral structure (16).
    [0008]
    A fibrous reinforcement according to claim 7, wherein the annular structure is obtained by three-dimensional weaving of a fibrous blank in the form of a band which is intended to be wound to form a ring.
    [0009]
    The fiber reinforcement of claim 8, wherein the fibrous blank of the annular structure comprises a plurality of warp thread layers extending in the lengthwise direction of the web and interconnected by weft threads.
    [0010]
    10. Fibrous reinforcement according to claim 7, wherein the annular structure is obtained by braiding.
    [0011]
    An elongated mechanical composite member 30 comprising a fibrous reinforcement according to any one of claims 1 to 10 densified by a matrix.
    [0012]
    12. Mechanical part according to claim 11, characterized in that it constitutes a lever (4a, 4b) of a strut (2) for landing gear. 20 25
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CH652176A5|1981-05-11|1985-10-31|Seger & Hoffmann Ag|Elongate force-transmission element and process for producing it|
    EP1308265A1|2001-11-02|2003-05-07|BPW Bergische Achsen Kommanditgesellschaft|Elongated shaped moulded part from fibre reinforced composite material|
    EP1736674A1|2005-06-24|2006-12-27|Snecma|Mechanical part and process to manufacture such a part|
    EP1798428A1|2005-12-13|2007-06-20|EADS Deutschland GmbH|Braided composite part|
    FR2970715B1|2011-01-21|2014-10-17|Snecma|MULTI-LAYER FABRIC FIBROUS STRUCTURE HAVING HOLLOW TUBULAR PART, MANUFACTURING METHOD AND COMPOSITE PIECE COMPRISING THE SAME|
    FR2978696B1|2011-08-01|2013-08-23|Messier Bugatti Dowty|ROD IN COMPOSITE MATERIAL HAVING INCREASED MECHANICAL STRENGTH|FR2970715B1|2011-01-21|2014-10-17|Snecma|MULTI-LAYER FABRIC FIBROUS STRUCTURE HAVING HOLLOW TUBULAR PART, MANUFACTURING METHOD AND COMPOSITE PIECE COMPRISING THE SAME|
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    US10563690B2|2016-07-28|2020-02-18|Goodrich Corporation|Thin-skin side stay beams and landing gear assemblies|
    IT201900005408A1|2019-04-09|2020-10-09|Univ Bologna Alma Mater Studiorum|POLYMER JOINT FOR MECHANICAL SUSPENSION OF LIGHT LAND VEHICLES|
    CN110937119A|2019-12-24|2020-03-31|肇庆市海特复合材料技术研究院|Integrated full-composite material connecting rod structure|
    WO2021258192A1|2020-06-26|2021-12-30|Safran Landing Systems Canada Inc.|Additive manufactured landing gear brace using preformed extruded metal as base material|
    法律状态:
    2015-02-24| PLFP| Fee payment|Year of fee payment: 2 |
    2016-02-15| PLFP| Fee payment|Year of fee payment: 3 |
    2017-02-13| PLFP| Fee payment|Year of fee payment: 4 |
    2017-06-23| CD| Change of name or company name|Owner name: MESSIER-BUGATTI-DOWTY, FR Effective date: 20170518 Owner name: SAFRAN, FR Effective date: 20170518 Owner name: SNECMA, FR Effective date: 20170518 |
    2018-01-23| PLFP| Fee payment|Year of fee payment: 5 |
    2018-02-02| CD| Change of name or company name|Owner name: SAFRAN AIRCRAFT ENGINES, FR Effective date: 20170719 Owner name: SAFRAN LANDING SYSTEMS, FR Effective date: 20170719 Owner name: SAFRAN, FR Effective date: 20170719 |
    2020-01-22| PLFP| Fee payment|Year of fee payment: 7 |
    2021-01-20| PLFP| Fee payment|Year of fee payment: 8 |
    2022-01-19| PLFP| Fee payment|Year of fee payment: 9 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1451489A|FR3017819B1|2014-02-25|2014-02-25|FIBROUS REINFORCEMENT FOR CARRYING OUT AN EXTENDED MECHANICAL PIECE OF COMPOSITE MATERIAL|FR1451489A| FR3017819B1|2014-02-25|2014-02-25|FIBROUS REINFORCEMENT FOR CARRYING OUT AN EXTENDED MECHANICAL PIECE OF COMPOSITE MATERIAL|
    US14/628,665| US9415863B2|2014-02-25|2015-02-23|Fiber reinforcement for making an elongate mechanical part out of composite material|
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