Connector for joining a first and a second element

Abstract

Connector (1) for connecting a first and a second element, comprising: a body (2) made of composite material comprising reinforcing fibers embedded in a resin-based plastic matrix (6b) and comprising a fastening zone for the first element; a ball joint (3) that is able to move by pivoting in a housing (4) of the body, and includes a bore (3b) for attaching the second element; a first fiber strip (7) or a coating having a coefficient of friction less than or equal to 0.1, positioned between the housing (4) and the ball joint (3), in contact with the ball joint (3); and a second fiber strip (8) having a coefficient of friction greater than or equal to 0.2, positioned between the housing (4) and the ball joint (3), in contact with the housing (4).

Description

Technical field of the invention

[0001] The present invention relates, in a general way, to connectors used to join two elements together.

[0002] More specifically, the invention relates to a connector, such as a bracket or tab, comprising a body made of a composite material and a ball joint mounted in the body. State of the art

[0003] In the aeronautics field, connectors such as metal brackets made of aluminum, titanium, or steel are conventionally used. Such connectors serve to connect two elements in a relative pivoting movement by means of a ball joint arranged between these elements and formed as a single unit with the connector. This is the case, for example, with a bracket for attaching a thrust reverser hood of an aircraft turbine.

[0004] The use of a connector made at least partially of composite material, i.e. of polymer material reinforced with fibers such as glass or carbon fibers, is particularly advantageous in areas where weight saving is important, such as aeronautics.

[0005] Document FR3067073 proposes a joint formed by a body made of composite material with reinforcing fibers embedded in a plastic matrix made of resin, such that the reinforcing fibers form layers with the resin which are stacked to form a laminate.

[0006] A mounting ring, placed between the ball joint and the housing of the body in which the ball joint is mounted, makes it possible to reduce the effects of the repeated forces generated during pivoting.

[0007] However, the integration of the mounting ring is expensive and laborious and makes the structure heavier.

[0008] Another embodiment, described in document FR3067073, consists in replacing the mounting ring with a self-lubricating fabric.

[0009] However, in the case of significant axial and radial loads applied to the body by the ball joint, the resin between the layers at the interface with the ball joint is subjected to stress. Repeated forces then cause the layers to separate, leading to premature delamination of the composite material around the housing formed to accommodate the ball joint. Brief description of the invention

[0010] The invention therefore aims to eliminate these drawbacks and to propose a lightweight and inexpensive connector capable of withstanding radial and axial tensile and compressive stresses in order to counteract the risks of delamination of the connector body.

[0011] The invention therefore proposes a connector for connecting a first and a second element, comprising: a body made of composite material comprising reinforcing fibers embedded in a plastic matrix made of resin and comprising a fixing zone for the first element; a ball joint capable of pivoting movement within a housing of the body and including a bore for securing the second member; a first fiber strip or coating having a coefficient of friction less than or equal to 0.1, positioned between the housing and the ball joint, in contact with the ball joint; and a second fiber strip having a coefficient of friction greater than or equal to 0.2, positioned between the housing and the ball joint, in contact with the housing.

[0012] Such a design makes it possible to maintain a weight and compactness of the connector compatible with an application in the aerospace field, while ensuring, on the one hand, friction characteristics sufficiently low to allow effective buckling of the ball joint without risk of delamination under continuous load, and, on the other hand, friction characteristics sufficiently high to protect the body of the connector from any risk of delamination under axial and radial loads.

[0013] The connector according to the invention is reliable and cost-effective, and its service life is optimized.

[0014] Advantageously, the first and second fiber strips are positioned in contact with each other.

[0015] According to an alternative embodiment in which the first fiber strip is replaced by a coating, the second fiber strip and the coating can be positioned in contact with each other.

[0016] “Coating” means a layer applied by chemical treatment or a layer attached to an outer surface of the ball joint.

[0017] Preferably, the first fiber strip or coating comprises lubricating particles comprising lubricating fibers impregnated with a binder, such as a resin, and / or at least one solid lubricant, wherein the lubricating particles or solid lubricant preferably comprise a fluoropolymer, such as polytetrafluoropolymer, graphite, molybdenum sulfide, hexagonal boron nitride, or a mixture thereof.

[0018] The lubricating particles make it possible to reduce the friction coefficient of the first fiber strip and to limit the friction between the body and the ball joint during pivoting.

[0019] Preferably, the first fiber strip comprises structural fibers selected from glass and / or carbon fibers. The structural fibers The structural fibers allow to retain the lubricating particles, such as fibers, whose mechanical performance is lower and which are lost during the Relative movement between the ball joint and the body of the connector could be torn under load.

[0020] Advantageously, the second fiber strip may comprise structural fibers impregnated with a binder, such as a resin, wherein the structural fibers are selected from glass and / or carbon fibers. The structural fibers make it possible to limit the risk of delamination of the connector body.

[0021] Preferably, the second fiber strip comprises a composite material identical to the composite material of the body to increase compatibility between the body and the second fiber strip.

[0022] According to one feature, the reinforcing fibers of the body form layers with the resin that extend perpendicular to the axis of the housing, and the second fiber strip can have layers that extend substantially perpendicular to these layers of the body. This makes it possible to reinforce the structure of the connector and further limit the separation of the layers of the connector body during pivoting.

[0023] In one embodiment, the first and second fiber strips can be attached to the body such that the ball joint is in motion relative to the assembly formed by the body and the first and second fiber strips. Such an arrangement is particularly simple to implement, facilitating the manufacture of the connector and reducing its manufacturing time. This also allows any type of ball joint to be integrated into the body of the connector.

[0024] According to an alternative, the first fiber strip or coating may be attached to the ball joint and the second fiber strip may be attached to the body, such that the assembly formed by the ball joint and the first fiber strip or coating is in motion relative to the assembly formed by the body and the second fiber strip.

[0025] In another embodiment, the second fiber strip may be attached to the body by impregnating the resin-made plastic matrix of the body.

[0026] Alternatively, the first and second fiber strips may be secured to the body by impregnating the resin-made plastic matrix of the body. This facilitates the integration of the first and second fiber strips and allows for the consolidation of the assembly formed by the body and the first and second fiber strips.

[0027] In an alternative embodiment, the first fiber strip may be attached to the ball joint by adhesive bonding.

[0028] In one embodiment, the second fiber strip may be attached to the body by adhesive bonding.

[0029] In another embodiment, the first and second fiber strips may be attached to the body by adhesive bonding. In this case, the second fiber strip may be attached in contact with the housing of the body, and the first fiber strip may be attached in contact with the second fiber strip. Short description of the characters

[0030] Further objects, advantages and features will become apparent from the following description, given by way of illustration only, with reference to the accompanying drawings in which: [ Fig. 1] is a perspective view of a holder according to an embodiment of the invention. [ Fig. 2] a view of the Fig. 1 illustrated bracket in cross section. Detailed description of the invention

[0031] Fig. 1 and Fig. 2 show a connector 1 intended to connect a first and a second element (not shown).

[0032] In the illustrated example, the connector is a bracket intended for an application in the aerospace field.

[0033] The connector 1 comprises a body 2 made of composite material having reinforcing fibers embedded in a plastic matrix 6b.

[0034] The fibers are advantageously made of carbon, but can also be made of another material, such as glass. The plastic matrix 6b is made of thermosetting resin, such as epoxy, but other materials such as thermoplastic resins, such as PEEK, PEKK, or PEAK, can also be used.

[0035] The body 2 of the connector 1 comprises a fastening zone for the first element to be connected, which in the illustrated example takes the form of a base 5. Screws or rivets could be used as means for fastening the first element to the connector 1.

[0036] The connector 1 also includes a ball joint 3 mounted in a housing 4—with axis X1—of the body 2. The housing 4 is delimited by an inner surface or bore of the body 2.

[0037] Advantageously, the ball joint 3 is made of metal, for example of titanium, steel, aluminum, bronze or an alloy thereof.

[0038] The bore of the housing 4 is spherical to interact with the ball joint 3.

[0039] The ball joint 3, with axis X2, is capable of pivoting within the housing 4 of the body 2. The connector 1 thus rigidly connects the first and second elements, while simultaneously allowing them to pivot relative to each other by pivoting the ball joint 3 within the housing 4.

[0040] The ball joint 3 may be formed from two parts that can be separated to allow mounting of the ball joint 3 in the housing 4.

[0041] Advantageously, the ball joint 3 has a spherical outer surface 3a intended to cooperate with the housing 4 for the articulation movement of the ball joint 3, and an inner surface or bore 3b for fixing the second element.

[0042] In the illustrated example, the bore 3b is cylindrical and has an axis X2.

[0043] The reinforcing fibers of the body 2 form layers or sheets 6a with the resin. These layers 6a are stacked to form a laminate, as shown in Fig. 2, which shows a longitudinal section of the connector 1 in a plane passing through the axis X1 and which is parallel to the layers 6a of the body 2.

[0044] To simplify the manufacture of the housing 2 of the connector 1, the layers 6a are advantageously parallel to each other. Furthermore, the layers 6a extend over the entire length of the body 2, except for the area of ​​the housing 4, where they are partially interrupted, for example, by removing material, to obtain the housing 4.

[0045] Furthermore, the connector 1 comprises a first fiber strip 7 having a friction coefficient less than or equal to 0.1, positioned between the housing 4 and the ball joint 3, in contact with the ball joint 3.

[0046] The first fiber strip 7 with a lubrication function enables the maintenance of a continuous load between the body 2 and the ball joint 3 by reducing the friction at the interface with the ball joint 3, and this also reduces the risk of delamination.

[0047] The first fiber strip 7 may comprise lubricating particles comprising lubricating fibers impregnated with a binder, such as a resin.

[0048] The first fiber strip 7 may also comprise at least one solid lubricant in addition to the lubricating particles or instead of the lubricating particles.

[0049] For example, the lubricating particles or solid lubricant may comprise a fluoropolymer such as polytetrafluoropolymer, graphite, molybdenum sulfide, hexagonal boron nitride, or a mixture of these.

[0050] Preferably, the first fiber strip 7 also comprises structural fibers, in particular in addition to the lubricating particles, in particular the lubricating fibers.

[0051] The structural fibers make it possible to reinforce the first fiber strip 7 by retaining the lubricating particles, such as fibers whose mechanical performance is lower and which could be torn under stress during the relative movement between the ball joint 3 and the body 2 of the connector 1.

[0052] The structural fibers also make it possible to resist the opening stresses transmitted to the body 2 of the connector 1 during the pivoting of the ball joint 3 supporting the second element, which tend to separate the layers 6a of the body 2.

[0053] The structural fibers of the first fiber strip 7 may be selected from glass fibers, carbon fibers or a mixture thereof.

[0054] Advantageously, the first fiber strip 7 can be a self-lubricating fabric.

[0055] According to an alternative, the first fiber strip 7 may be replaced by a coating which is at least partially applied to the outer surface 3a of the ball joint 3 and has a friction coefficient of less than or equal to 0.1.

[0056] The coating may be a layer obtained by chemically treating the outer surface of the ball joint 3 or a layer attached to the outer surface of the ball joint 3, such as forming a lining.

[0057] Preferably, the coating is applied to the entire outer surface 3a of the ball joint 3.

[0058] The coating may comprise lubricating particles comprising lubricating fibers impregnated with a binder such as a resin.

[0059] The coating may comprise at least one solid lubricant in addition to the lubricating particles or instead of the lubricating particles.

[0060] For example, the lubricating particles or solid lubricant may comprise a fluoropolymer such as polytetrafluoropolymer, graphite, molybdenum sulfide, hexagonal boron nitride, or a mixture of these.

[0061] Preferably, the coating also comprises structural particles such as fibers, for example glass fibers, carbon fibers or a mixture of these.

[0062] Furthermore, the connector 1 comprises a second fiber strip 8 having a friction coefficient greater than or equal to 0.2, positioned between the housing 4 and the ball joint 3, in contact with the housing 4.

[0063] In the illustrated example, the first and second fiber strips 7 and 8 are positioned in contact with each other.

[0064] The first fiber strip 7 comprises an inner surface in contact with the outer surface 3a of the ball joint 3 and an opposite outer surface in contact with an inner surface of the second fiber strip 8.

[0065] The second fiber strip 8 comprises an inner surface in contact with the outer surface of the first fiber strip 7 or the coating and an outer surface in contact with the housing 4.

[0066] According to an alternative embodiment in which the first fiber strip 7 is replaced by a coating, the second fiber strip 8 and the coating can be positioned in contact with each other.

[0067] The coating comprises an inner surface in contact with the outer surface 3a of the ball joint 3 and an opposite outer surface in contact with an inner surface of the second fiber strip 8.

[0068] The second fiber strip 8 comprises an inner surface in contact with the outer surface of the coating and an outer surface in contact with the housing 4.

[0069] Preferably, the second fiber strip 8 comprises structural fibers impregnated with a binder, such as a resin. The structural fibers may be selected from glass fibers, carbon fibers, or a mixture thereof.

[0070] The second fiber strip 8 may advantageously comprise a composite material identical to the composite material of the body 2 in order to improve the compatibility between the body 2 and the second fiber strip 8.

[0071] In the example illustrated, the reinforcing fibers of the body 2 form with the resin layers 6a extending perpendicular to the axis X1 of the casing 4, at least in the zone of the body 2 around the casing 4, and extending over a few millimeters or a few tens of millimeters, and this makes it possible to increase the tensile and compressive strength.

[0072] The second fiber strip 8 may also have layers. Preferably, the layers of the second fiber strip 8 extend transversely along the fiber strip 8, so that they extend substantially perpendicular to the layers 6a of the body.

[0073] The first fiber strip 7 can also have at least one layer.

[0074] The thickness of the first fiber strip 7, the thickness of the coating and the thickness of the second fiber strip 8 are preferably in the order of millimeters, between 0.5 and 5 mm.

[0075] For example, the first fiber strip 7 and the second fiber strip 8 have a layer content of 10% and 90%, respectively.

[0076] This ratio can be set as a function of the required ratio between the continuous swing load and the static load.

[0077] In one embodiment, the first and second fiber strips 7 and 8 can be attached to the body 2. In this way, the ball joint 3 is in motion relative to the assembly formed by the body 2 and the first and second fiber strips.

[0078] In an alternative embodiment, the first fiber strip 7 or the coating can be attached to the ball joint 3, while the second fiber strip 8 is attached to the body 2. In this way, the assembly formed by the ball joint 3 and the first fiber strip 7 or the coating is in motion relative to the assembly formed by the body 2 and the second fiber strip 8.

[0079] Preferably, the attachment of the second fiber strip 8 or the attachment of the first and second fiber strips 7 and 8 to the body 2 is realized by impregnation of the resin-made plastic matrix 6b of the body 2.

[0080] As an alternative, the first fiber strip 7, the second fiber strip 8 or the first and second fiber strips 7, 8 may also be attached by adhesive bonding.

[0081] According to one example, the second fiber strip 8 may be secured in contact with the housing 4 by means of an adhesive, and the first fiber strip 7 may be secured in contact with the second fiber strip 8, also by means of an adhesive.

[0082] According to another example, the second fiber strip 8 may be fixed in contact with the housing 4 by means of an adhesive, and the first fiber strip 7 may be fixed in contact with the ball joint 3, also by means of an adhesive.

[0083] In the illustrated example, the connector 1 is configured to connect two elements.

[0084] As an alternative, the connector 1 may also be implemented to connect three or more elements together.

[0085] Furthermore, the invention can also be applied to a type of connector other than a bracket, for example a rod end or a tab, for example also for an application in the aerospace field or any other technical field. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] FR 3067073 [0005, 0008]

Claims

[1] Connector (1) for connecting a first and a second element, comprising: a body (2) made of composite material comprising reinforcing fibers embedded in a plastic matrix (6b) made of resin and comprising a fixing zone for the first element; a ball joint (3) capable of pivoting within a housing (4) of the body and comprising a bore (3b) for securing the second element; a first fiber strip (7) or coating having a coefficient of friction less than or equal to 0.1, positioned between the housing (4) and the ball joint (3), in contact with the ball joint (3); and a second fiber strip (8) having a friction coefficient greater than or equal to 0.2, positioned between the housing (4) and the ball joint (3), in contact with the housing (4). [2] Connector according to claim 1, wherein the first fiber strip (7) or the coating comprises lubricating particles comprising lubricating fibers impregnated with a binder, such as a resin, and / or at least one solid lubricant, wherein the lubricating particles or the solid lubricant preferably comprise a fluoropolymer, such as polytetrafluoropolymer, graphite, molybdenum sulfide, hexagonal boron nitride or a mixture thereof. [3] A connector according to claim 2, wherein the first fiber strip (7) comprises structural fibers selected from glass and / or carbon fibers. [4] A connector according to any one of claims 1 to 3, wherein the second fiber strip (8) comprises structural fibers impregnated with a binder such as a resin, the structural fibers being selected from glass and / or carbon fibers. [5] A connector according to any one of the preceding claims, wherein the second fiber strip (8) comprises a composite material identical to the composite material of the body (2). [6] A connector according to any one of the preceding claims, wherein the reinforcing fibers of the body (2) form with the resin layers (6a) extending perpendicular to the axis of the housing (4), and the second fiber strip (8) has layers extending substantially perpendicular to the layers (6a) of the body (2). [7] A connector according to any one of the preceding claims, wherein the first and second fiber strips (7, 8) are positioned in contact with each other or the coating and the second fiber strip (8) are positioned in contact with each other. [8] A connector according to any one of the preceding claims, wherein the first and second fiber strips (7, 8) are attached to the body (2) such that the ball joint (3) is in motion relative to the assembly formed by the body (2) and the first and second fiber strips (7, 8). [9] A connector according to any one of the preceding claims, wherein the second fiber strip (8) or the first and second fiber strips (7, 8) are fixed to the body (2) by impregnation of the resin-made plastic matrix (6b) of the body (2). [10] Connector according to one of the preceding claims, wherein the first fiber strip (7) and / or the second fiber strip (8) are fixed to the body (2) or to the ball joint (3) by an adhesive.

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