Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
  • B64D45/00—Aircraft indicators or protectors not otherwise provided for
  • B64D45/02—Lightning protectors; Static dischargers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L25/00—Constructive types of pipe joints not provided for in groups F16L13/00 - F16L23/00 ; Details of pipe joints not otherwise provided for, e.g. electrically conducting or insulating means
  • F16L25/01—Constructive types of pipe joints not provided for in groups F16L13/00 - F16L23/00 ; Details of pipe joints not otherwise provided for, e.g. electrically conducting or insulating means specially adapted for realising electrical conduction between the two pipe ends of the joint or between parts thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L25/00—Constructive types of pipe joints not provided for in groups F16L13/00 - F16L23/00 ; Details of pipe joints not otherwise provided for, e.g. electrically conducting or insulating means
  • F16L25/02—Electrically insulating joints or couplings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L27/00—Adjustable joints, Joints allowing movement
  • F16L27/12—Adjustable joints, Joints allowing movement allowing substantial longitudinal adjustment or movement
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L39/00—Joints or fittings for double-walled or multi-channel pipes or pipe assemblies
  • F16L39/04—Joints or fittings for double-walled or multi-channel pipes or pipe assemblies allowing adjustment or movement
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G13/00—Installations of lightning conductors; Fastening thereof to supporting structure

Definitions

• the present invention relates to a device for protecting pipelines against lightning and more specifically a protection device piping for transporting fuel in aircraft.
• the invention applies more particularly to the case of aircraft whose primary structure and the fuselage consist of a composite material, non-conductive or weakly conductive.
• the metal pipe is more conductive than the fuselage and there is a risk of lightning current flow in the metal tubes constituting the fuel pipes.
• the solution of the present invention comprises an integration of insulating or more resistive parts than the structure in fuel pipelines.
• the present invention proposes a protection device for pipes against lightning, for which, the pipework consisting of metal tubular sections connected to each other by connecting pieces, a first part of the connecting pieces are pieces of material plastic and a second part of the connecting pieces are metal parts.
• the pipes of the pipe being double-skinned tubes comprising an inner tube and a concentric outer tube
• the connecting pieces comprise an internal connecting part of two inner tubes and an outer piece connecting two outer tubes.
• the plastic material connecting pieces comprise stop means adapted to maintain a spacing intended to prevent the creation of an electric arc between the tubes that they connect.
• the sealing means between the tubes and the connecting pieces having electrical insulating O-rings the device comprises electrical connection means between at least some of the tubes and at least some of the connecting pieces.
• the connecting pieces of plastic material are made of a plastic material comprising an insulating polymer and a charge of a conductive material so as to make the material sufficiently conductive to evacuate the static electricity accumulated by the tubes. .
• the charge is advantageously a charge of carbon fibers.
• connection of the sections being at the level of fixing support of the fixation on the structure, a first section is received by a metal part, the other being received by a plastic part said piece metal and plastic part being assembled together.
• the metal part is a fitting attached to the recovery support.
• the plastic part comprises at least one sleeve which is fixed on the coupling.
• the plastic part comprises an outer sleeve and an inner sleeve, the inner sleeve comprising a first part forming a receiving end of an end of an inner tube of the first section or a extension tube of said inner tube and a second portion forming a connecting piece of an inner tube of the second section.
• connection forms a mixed metal / plastic connection.
• the invention furthermore relates to an aircraft comprising metal pipe sections and a pipe protection device according to the invention for which the sections of the pipework are connected, at a first of their ends, by means of insulating connecting pieces and at one second of their ends, by means of conductive connecting pieces and electrically connected to the structure, so as to produce pipe segments comprising two sections each connected to the electrical mass of the aircraft, said segments being electrically isolated from the each other.
• the connecting pieces comprising electrical insulating O-rings, electrical connection means are preferably arranged between the tubes and the metal connecting pieces.
• the aircraft may be such that it comprises metal pipe sections and a pipe protection device comprising charged plastic connection parts, for which a majority of sections of the pipework are connected by means of parts.
• charged plastic connection connectors, metallic connecting pieces electrically connected to the structure being arranged from place to place to connect the piping locally to the electrical ground of the aircraft.
• the metal connecting pieces are placed every fifteen meters of piping approximately.
• the aircraft is such that it comprises sections of metal piping and a pipe protection device comprising conductive parts and insulating parts for which the sections of the pipework are connected at a first end thereof. , by means of insulating connecting pieces and, at a second of their ends, by means of conductive connecting pieces and electrically connected to the structure, so as to produce segments of piping each section of which is connected to the electrical ground of the aircraft to one of its ends and isolated at the other end thereof, said segments being electrically isolated from each other.
• the invention furthermore relates to a method for the protection against lightning of pipes of an aircraft made from a plurality of tubular sections connected together by connection pieces, characterized in that a first part of the connecting pieces being made of non-conductive material of electricity and a second part of the connecting pieces being made of conductive material is connected to the tubular sections to each other alternating conductive connecting parts electrically connected to the structure of the aircraft and parts non-conductive connection.
• the method is a lightning protection method for piping an aircraft made from a plurality of tubular sections interconnected by high-resistivity connection pieces adapted to discharge electrostatic charges, for which is connected the tubular sections to said high-resistivity connecting parts by means of connection braids and there is periodically a metallic connection piece of electrical grounding of the aircraft every 10 to 20 meters of piping and preferably about all the 15 meters of piping.
• Figure 1 a perspective view of a pipe section between connecting pieces
• FIG. 2 a side view of connections of several sections
• FIG. 3 a cut-away perspective view of a connection of sections of the invention
• FIG. 1 shows a section 1 of such a kerosene feed pipe of an aircraft.
• It is a tubular section made from tubes of any section, cylindrical or otherwise.
• connection pieces A for fixing the piping to structural elements of the aircraft along which the pipe runs.
• FIG. 1 A more detailed example showing a section of tubes 2a, 2b and two ends of sections 1a, 1b and 3a, 3b is given in FIG.
• the route of fuel pipes consists of double skin tubes 1a, 1b, 2a, 2b, 3a, 3b that is to say that the tube carrying the kerosene 1b, 2b, 3b is protected by a second tube 1a, 2a, 3a which makes it possible to recover any leaks and to contain external aggression, in particular fire.
• the device of the invention must resist kerosene, the outer skin must also withstand a temperature of 1100 0 C for 5min.
• This outer skin must allow evacuation of electrostatic charges to the metal structure 30, 31 of the aircraft, avoid arcing and allow the use of existing standard parts.
• the outer tube is made of aluminum and the inner tube made of titanium.
• the resistivity of the structure is important so that metal pipes become possible paths for lightning.
• the connecting pieces of the present invention are intended to create obstacles preventing the passage of lightning through the pipes.
• parts 4a, 4b and 51 of Figure 2 are parts of insulating plastic material.
• connection pieces shown in perspective cut in FIG. 3 remain traditional in their mechanical function of connecting the tubes.
• An inner piece 51 connects the inner tubes 1b and 2b terminated by sleeves 10a provided with an O-ring seal 9b.
• the inner part has abutment shoulders 8 which prevent the tubes from getting closer to a distance less than a given electrical insulation distance according to applicable standards and in this case
• the outer part is here in two parts 4a and 4b made so that a minimum distance of 10mm of air gap between the inner part and the outer parts is respected.
• This two-piece part receives the outer tubes 1a, 2a at its two ends, the outer tubes being also equipped with end caps
• plastic parts allow mechanical recovery on the structure by means of fastening means such as holes 7 and the electrical insulation of the fuel piping at one of the 2 ends of a section.
• Figure 4 shows a sectional view of a portion of the connection to see the possible movement of the tubes 1a, 1b relative to the connecting pieces.
• the connecting pieces 6a, 6b are made of metal elements to allow evacuation of electrostatic charges.
• electrical connection means such as metal braids welded to the tubes and / or the connecting pieces or connected to the connecting pieces by assemblies screws / nuts are provided to allow electrical continuity, in particular between the connecting pieces 6a, 6b and the tubes 1a or between the tubes and the recovery support 32.
• the metallization braids are for example made of copper with protective tinning.
• FIG. 5 corresponds to a variant of the invention that is particularly suitable when the connections of the sections are made at the level of recovery supports 32 for attachment to the structure 30.
• a first section is received by a metal part 35, the other being received by a plastic part 36, said metal part and plastic part 35, 36 being assembled together.
• the metal part 35 is here a connection fixed to the recovery support 32 by means for example of a fixing plate 39 screwed onto the support.
• This metal part ensures the connection of the first section and the mechanical attachment of this section to the structure.
• the plastic part 36 is fixed on the metal part and ensures the connection of the second section and to do this it comprises at least one sleeve 36a attaching to the connection 35.
• the plastic part comprises an outer sleeve 36a for connecting the outer tube and an inner sleeve 36b for connecting the inner tube.
• the inner sleeve 36b comprises a first part forming a tip 37 for receiving an end of an inner tube of the first section or an extension tube
• the extension tube 40 is useful in particular if one uses outer inner tubes of the same length and it is necessary to extend the inner tube to ensure continuity of fuel passage.
• the spacer is preferably metallic to connect the end of the inner tube of the first section to the structure and therefore to the mass of the aircraft.
• ground braids are optionally provided to bridge the play catch device and put the inner and outer tubes to ground.
• connection forms a mixed metal / plastic connection.
• the aircraft then comprises sections of metal piping and a pipe protection device for which the sections of the pipework are connected, at a first end thereof, by means of insulating connecting pieces and, at a second of their ends, by means of conductive connecting pieces and electrically connected to the structure, so as to produce segments of piping each section of which is connected to the electrical mass of the aircraft at one of its ends and isolated at the other of its ends, said segments being electrically isolated from each other.
• This variant allows to completely segment the electrical pipe to prevent any lightning current flow while discharging the electrostatic charges at each section.
• the insulating fittings are advantageously made of fiber-reinforced PEEK.
• the fibers do not need to be conductive.
• plastic connectors are made so as to offer a conductivity sufficient to evacuate the static electricity charges caused by the friction of the liquid in the pipes.
• the PEEK is too insulating that is why it must be loaded with conductive fibers such as carbon fibers.
• a loading with fibers of the order of 3 to 5 mm is a value answering the problem of the realization of sufficiently resistive parts not to serve as a path to lightning but sufficiently conductive to evacuate the charges of static electricity.
• the solution for making the parts is a material that is resistant to fuel and the choice is for a PEEK loaded with short fibers. By measuring the concentration of short fibers, the fire resistance, the conductivity / resistivity and the resistance to the desired forces are obtained.
• the invention then provides a low mass solution which provides protection of lightning currents and evacuation of electrostatic currents.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Aviation & Aerospace Engineering (AREA)
• Elimination Of Static Electricity (AREA)
• Flanged Joints, Insulating Joints, And Other Joints (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41718578

Family Applications (1)

Country Status (8)

Families Citing this family (28)

Family Cites Families (13)

• 2009
  • 2009-07-16 FR FR0954938A patent/FR2948254B1/fr active Active
• 2010
  • 2010-07-13 US US13/383,436 patent/US8947846B2/en active Active
  • 2010-07-13 WO PCT/FR2010/051481 patent/WO2011007100A2/fr active Application Filing
  • 2010-07-13 RU RU2012105343/11A patent/RU2546375C2/ru not_active IP Right Cessation
  • 2010-07-13 EP EP10752013A patent/EP2454155A2/fr not_active Withdrawn
  • 2010-07-13 CN CN201080057397.8A patent/CN102712370B/zh active Active
  • 2010-07-13 CA CA2767178A patent/CA2767178C/fr active Active
  • 2010-07-13 JP JP2012520074A patent/JP2012532797A/ja active Pending

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events