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EP-3608095-B1 - COMPOSITE CONNECTORS AND METHODS OF MANUFACTURING THE SAME

EP3608095B1EP 3608095 B1EP3608095 B1EP 3608095B1EP-3608095-B1

Inventors

  • BERNARD, JAMES
  • POLLITT, Will

Dates

Publication Date
20260506
Application Date
20180810

Claims (13)

  1. A method of manufacturing a connector (2, 102, 202) for a fluid transfer conduit (4, 104), the method comprising: manufacturing a tube (204) which runs parallel to a central axis (C) from fibre-reinforced polymer, said tube (204) comprising a hub portion (6, 106, 206, 306) and a flange-forming portion (8, 108, 208, 308) located adjacent to the hub portion (6, 106, 206, 306), wherein the hub portion (6, 106, 206, 306) comprises continuous circumferentially oriented fibre-reinforcement (110, 210); and the hub portion (6, 106, 206, 306) and the flange-forming portion (8, 108, 208, 308) comprise longitudinally oriented fibre-reinforcement (112, 212) which runs continuously from the hub portion (6, 106, 206, 306) into the flange-forming portion (8, 108, 208, 308); and bending the flange-forming portion (8, 108, 208, 308) away from the central axis (C) such that it extends from the hub portion (6, 106, 206, 306) at an angle to the central axis (C). characterised in that the connector (2, 102, 202) comprises a thermoplastic polymer matrix, and bending the flange-forming portion (8, 108, 208, 308) comprises heating a boundary region between the hub portion (6, 106, 206, 306) and the flange-forming portion (8, 108, 208, 308) before bending the flange-forming portion (8, 108, 208, 308) away from the central axis (C).
  2. The method of manufacturing a connector (2, 102, 202) for a fluid transfer conduit (4, 104) according to claim 1, wherein manufacturing the tube (204) involves using an automated fibre placement technique.
  3. The method of manufacturing a connector (2, 102, 202) for a fluid transfer conduit (4, 104) according to any preceding claim, further comprising forming one or more longitudinal slits (213) in the flange-forming portion (8, 108, 208, 308) to form a plurality of separate flange sections (209), before bending the flange-forming portion (8, 108, 208, 308) away from the central axis (C).
  4. The method of manufacturing a connector (2, 102, 202) for a fluid transfer conduit (4, 104) according to any preceding claim, further comprising forming at least one through-hole (10, 114, 214, 310) in the flange-forming portion (8, 108, 208, 308) by inserting a tapered rod (216) through the flange-forming portion (8, 108, 208, 308).
  5. The method of manufacturing a connector (2, 102, 202) for a fluid transfer conduit (4, 104) according to any preceding claim, wherein manufacturing the tube (204) comprises manufacturing a single structure comprising several tubes and separating said structure into separate tubes.
  6. A connector (2, 102, 202) for connecting a fluid transfer conduit (4, 104) to another structure, the connector (2, 102, 202) being made from fibre-reinforced polymer according to the method of claim 1and comprising: a hub portion (6, 106, 206, 306) comprising a tube which extends substantially parallel to a central axis (C), the hub portion (6, 106, 206, 306) being arranged to fit onto or into a fluid transfer conduit (4, 104); and a flange portion (8, 108, 208, 308) which extends from the hub portion (6, 106, 206, 306) at an angle to the central axis; wherein the hub portion (6, 106, 206, 306) comprises continuous circumferentially-oriented fibre reinforcement (110, 210); and wherein the connector (2, 102, 202) comprises longitudinally oriented fibre reinforcement (112, 212) which runs continuously from the hub portion (6, 106, 206, 306) into the flange portion (8, 108, 208, 308); characterised in that the connector (2, 102, 202) comprises a thermoplastic polymer matrix.
  7. The connector (2, 102, 202) according to claim 6, wherein there is little or no circumferentially-oriented fibre reinforcement present in the flange portion (8, 108, 208, 308).
  8. The connector (2, 102, 202) according to claim 6 or 7, wherein the flange portion (8, 108, 208, 308) comprises at least one through-hole defined by unbroken fibre reinforcement.
  9. The connector (2, 102, 202) according to any of claims 6-8, wherein the flange portion (8, 108, 208, 308) comprises a plurality of separate flange sections (209) spaced around the central axis (C), each flange section (209) extending from the hub portion (6, 106, 206, 306) at a respective angle to the central axis (C).
  10. The connector (2, 102, 202) according to claim 9, wherein the respective angles at which the flange sections (209) extend are equal.
  11. The connector (2, 102, 202) according to claim 9, wherein at least two of the respective angles at which the flange sections (209) extend are different.
  12. The connector (2, 102, 202) according to claim 9, wherein the flange portion comprises four flange sections (209) spaced equiangularly around the central axis (C), and each flange section (209) extends perpendicularly to the central axis (C).
  13. A connection system comprising the composite connector (2, 102, 202) as claimed in any of claims 6-12 and a fibre-reinforced polymer fluid transfer conduit (4, 104) connected to the hub portion (6, 106, 206, 306), wherein the composition and orientation of the fibre reinforcement (110, 210) within the hub portion (6, 106, 206, 306) is selected such that the coefficient of thermal expansion and/or the stiffness of the hub portion (6, 106, 206, 306) substantially matches that of the fluid transfer conduit (4, 104).

Description

Technical Field The present disclosure relates to composite (e.g. fibre-reinforced polymer) connectors e.g. for connecting fluid transfer conduits to other structures, and to methods of manufacturing composite (e.g. fibre-reinforced polymer) connectors for fluid transfer conduits. Background Fluid transfer conduits (e.g. fuel pipes) are typically connected to other structures (e.g. inside aeroplane wings) using one or more connectors. To allow for movement of the fixed structure without inducing large stresses on the fluid transfer conduit itself (e.g. as a wing flexes during flight), such connectors are designed to tolerate a small amount of relative movement between the fluid transfer conduit and the structure whilst still effectively supporting the conduit and sealing the connection. This is often achieved using an elastomeric O-ring, on which the fluid transfer conduit "floats", to seal the connection while allowing a small amount of relative motion. In many applications, such connectors are required to withstand large circumferential loads (e.g. due to high internal pressures in a fluid transfer conduit) as well as other stresses. To provide the requisite strength while minimising part count connectors are conventionally milled from a single block of metal (usually aluminium). However, this process results in a large amount of material being wasted (a very high so-called buy-to-fly ratio). Furthermore, fluid transfer conduits are increasingly being constructed from composite materials (e.g. fibre-reinforced polymers), in order to save weight and reduce material costs. However, when used with metallic connectors, composite fluid transfer conduits can experience various problems such as galvanic corrosion and a reduced temperature operating window due to unequal thermal expansion. More recently therefore, an alternative manufacturing technique has been developed whereby connectors are produced by injection-moulding a resin matrix reinforced with randomly oriented chopped fibres (e.g. glass or carbon fibres). Because injection-moulding is an additive process, it results in less wasted material during manufacture. In addition, chopped-fibre reinforced resin parts are typically lighter than their metal equivalents. However, chopped-fibre reinforcement does not exploit fully the potential strength of reinforcing fibres. US 2013/0266431 discloses a method of forming a composite structure comprising a main body and a flange by laying-up a preform comprising a plurality of plies on a mould and then forming the flange by advancing movable portions of the mould. GB 2033992 discloses a fibre reinforced plastics pipe with an integral flange comprising circumferentially extending glass fibre fabrics. US 3,920,049 discloses a plastics tube with a fibre reinforcement of tubular endless knitted fabric impregnated with duroplastic material, wherein the ends of the tube are provided with flanges. The endless tubular knitted fabric extending radially outwards into the flange and being impregnated with a circular insert. EP 3 332 946 discloses a composite tube comprising a body having a longitudinal centreline axis and an end potion including a plurality of segments that are angled relative to the longitudinal centreline axis. Summary According to one aspect of the present disclosure, there is provided a method of manufacturing a connector for a fluid transfer conduit according to claim 1, and a connector according to claim 6. Because of the high strength-to-weight ratio of continuous fibre-reinforced polymer, the use of continuous fibre-reinforcement can produce a significantly stronger part using the same amount of material compared to randomly-oriented fibre reinforcement or entirely metal parts. Correspondingly, an equally strong part may be produced using less material, thus saving weight. The connector according to the present disclosure may be produced using additive processes. This means that there is little material wasted during manufacture, especially compared to machining-techniques used to construct conventional metal components. As a result, the cost of manufacturing a connector according to the present disclosure may be less than for an equivalent metal component, even if the underlying material costs are higher (due to less material going to waste). When continuous fibre-reinforcement is used to make a given component, the orientation of the continuous fibres can be tailored to the direction in which the resulting component will experience loads. Lots of fibres may be oriented in a primary direction of loading, and a lower proportion of fibres may therefore be oriented in directions in which the component experiences little load. This minimises the amount of material wasted when producing a part with a given load capacity. In this case, continuous circumferential fibre in the hub portion provides increased hoop (circumferential) strength, improving the connector's resistance to high radial loads (e.g. due t