Patent Application
20130161940
This application claims priority to France Application No. 11 60929 filed Nov. 30, 2011, the entire contents of which is hereby incorporated herein by reference.
The invention concerns a device for fastening a fluid transport circuit to an element of the structure of an aircraft and the related aircraft. The invention can be advantageously applied for fluid transport circuits containing two concentric tubes, for example an interior fuel line and an external conduit allowing circulation of air between the internal and the external tubing. The term “tubing” indicates a group of several tubes of the same diameter assembled to form a sealed system.
Fluid transport circuits are generally attached to structural elements of an aircraft during its construction. The circuit is accomplished in several portions that are assembled to the interior of the aircraft when the structure is being built.
Some fluid transport circuits in aircraft are made up of two tubing elements. Internal tubing transports the fluid, with a space located between the external and internal tubing. This space can be used for flow of another fluid, air or simply as protection of the internal tubing.
Fluid transport circuits with two concentric tubes are more complex to maintain on structures in an aircraft than standard fluid transport circuits, which have only one tube. Standard devices for holding tubes in place generally include a ring clamped around a tube and a metallic plate connected to the ring, with the metallic plate having a mechanical interface with a structural element of the aircraft.
These standard fastening devices 10 cannot be used for supporting the heavy weight that tubing and fluids within it can represent. Thus, for each portion of a fluid transport circuit, several fastening devices 10 are necessary. These fastening devices 10 greatly increase the weight of the structure of an aircraft. It is known to reduce the weight of these fastening devices 10 by leaving hollows 19 in the center of the plate 15.
However, as fluid transport circuits that have two tubes are heavier, more fastening devices are required. Multiple fastening devices in each portion complicate installation and maintenance operations of portions of tubing in the fluid transport circuit. In addition, at each fastening device, the risk of cutting the tube is heightened, thus increasing the risk of leaks in the tubing.
Document WO 2007/057629 describes a fastening device between two portions of a fluid transport circuit containing two tubes. The fastening device both functions as a connecting junction between two portions of the fluid transport circuit and as support for the fluid transport circuit. However, this device cannot transmit mechanical forces between the two portions of the fluid transport circuit.
This invention proposes to reduce the number of fastening devices for a fluid transport circuit containing two tubes, an internal tube and an external tube. To this end, the invention proposes a fastening device at the junction of two portions of a fluid transport circuit in order to maintain appreciably constant radial clearance between the tube of the internal tubing and the tube of the external tubing of the two portions. As this device will make the structure of the dual tube fluid transport circuits more rigid, it will thus be possible to reduce the number of connections between the circuits and the aircraft structure.
According to an initial embodiment, the invention concerns a device for fastening a transport fluid circuit to an element of the structure of an aircraft with the fluid transport circuit made up of an external tube positioned around an internal tube.
The device is characterized in that as the fastening device is located at the junction between the two portions of the fluid transport circuit, it contains a body with a plate intended to fix the fastening device to the structural element of the aircraft, with this body capable of providing at least one sealed connection between the external tubes of the two portions and a support system that will guarantee appreciably constant radial clearance between the internal tube and the external tube of the two portions of the fluid transport circuit.
This invention will allow the fastening device to serve as both a hydraulic connection between two portions of the fluid transport circuit and as support for the fluid transport circuit. The support function implies mechanical continuity between the two portions of the fluid transport circuit to ensure the transmission of actions involving mechanical actions, forces and moments, between the portions of the circuit and between the said portions and the structure to which they are attached.
As such, the device can be used to significantly reduce the number of fastening devices of a portion of the fluid transport circuit. Reducing the number of fastening devices decreases the risk of cuts in the tubing, and therefore the risk of leaks. Not only does the invention facilitate installation and maintenance of the fluid transport circuit, it also reduces the weight allotted to fastening the fluid transport circuit.
In one embodiment, the support system is made up of an added junction mechanism attached to the internal tube that links the internal tube to the end piece of the body.
In one embodiment, the body contains a cylindrical part connected to the plate with a diameter appreciably equal to the diameter of the external tube of a portion, with the cylindrical part intended to be welded to an end of the an external tube of a portion.
In one embodiment, the body containing an internal junction passing through the body with a diameter appreciably equal to the diameter of the internal tube of the portions and the support system is formed by at least one spacer piece located between the body and the internal junction, with the body, the internal junction and the spacer piece forming a single piece.
In one embodiment, the body, the internal junction and the spacer piece are molded.
In one embodiment, the fastening device is made of a conductive material that provides electrical continuity between the two portions and the structure of the aircraft when these portions are made of conductive materials.
In one embodiment, the plate contains a mechanical interface that can attach to a sleeve when the end of an external tube of a portion is made up by a sleeve. The sleeve is used to access the mechanical junction between the internal tubes of the portions of the circuit during installation of the tubing in the structure of the aircraft.
In a second embodiment, the invention concerns a device for fastening a fluid transport circuit to an element of the structure of an aircraft.
The invention will be better understood by reading the following description and reviewing the accompanying drawings. These drawings are provided only as an illustration and under no circumstances limit the invention. They show the following:
The Figures are not to scale.
Identical, similar or analogous elements keep the same reference from one figure to the next.
As detailed in
The plate 27 has a mechanical interface 32 intended for connecting the fastening device 10 to an element of the structure of an aircraft. To this end, the plate 27 has four bore holes 31 for allowing the means of fixing by either screw or bolt. The plate 27 also contains a mechanical interface 33 (detailed in
Preferably, the fastening device 10 is made of a conductive material that provides electrical continuity between the tubes and/or the structure of the aircraft. Electrical conductivity of the tubes and/or the aircraft structure allows ESN electrical functions in a network, ensuring electric functionalities such as return current and grounding of various electrical equipment installed in the aircraft.
In addition, we can see the internal tube 43 of the second portion 42 is connected to the internal tube 21 of the first portion 23 by means of a sealed connection 40. In the example of
The assembly process of the two portions 23, 42 of the fluid transport circuit to the fastening device 10 contains a phase of fastening the body 26 to the external tube 22 of the first portion 26, for example by a solder fillet. In a variant, the end of the external tube 22 containing a sleeve, said sleeve is assembled with a dedicated mechanical interface onto the body 26. Another stage of assembly consists in fastening the connecting system 41 to the internal tube 21. The internal tube 21 is introduced into the interior of the circular body 29 of the body 26, then to the interior of the external tube 22 until the connecting system 41 comes into contact with the side of the body end 26. The connecting system 41 is connected to the body 26 by implementing a means of fastening. The internal tube 43 of the second portion that is surrounded by the external tube 44 is connected to the internal tube 21 of the first portion 23 by implementing the connection 40. The sleeve 46 surrounding the external tube 44, as in
During maintenance on the connection 40 located between the two internal tubes 21, 43, for example in the event of a leak, the fastener is removed between the mechanical interface 36 and the flange 55 of the sleeve 46. The sleeve 46 is translated to access the connection 40. Personnel can thus easily work on the connection 40 without having to disassemble numerous elements of the fluid transport circuit.
The two external tubes 22, 44 of the two portions 23, 42 are connected to the ends of the cylindrical body by means of sleeves 60, 66 located above the connections 63, 64 so as to allow easy access to the said connections 63, 64. For this purpose, the sleeves 60, 66 are attached to the body ends 26 by two mechanical interfaces 70 of the screw and bolt type. The connections 63, 64 constitutes a means of fastening that connects the internal tubes 21, 43 mechanically, achieving a mechanical connection in addition to a sealing function.
Radial clearance is guaranteed between the internal tube 21, 43 and the external tube 22, 44 of each portion 23, 43 by means of a spacer piece 75 positioned around the internal junction 62 between the body 26 and the internal junction 62. The spacer piece 75 has openings allowing air or fluid to circulate in the space between the two tubes. The body 26, the internal junction 62 and the spacer piece 75 form one single and like piece, preferably manufactured by molding.
The assembly procedure of the two portions 23, 42 of the fluid transport circuit with the fastening device 10 contains a connecting phase of the internal tube 21 to the internal junction 62 by implementing the connection 64. Likewise, the implementation of the connection 63 allows a connection between the internal tube 43 and the internal junction 62. The sleeve 60 surrounding the external tube 22 is translated along the external tube 22 so as to come into contact with the mechanical interface 70 of the body 26. A means of fastening is implemented to mechanically connect the flange of the sleeve 60 with the mechanical interface 70. In the same way, the sleeve 66 surrounding the external tube 22 is translated along the external tube 22 so as to come into contact with the mechanical interface 70 of the body 26. A means of fastening is implemented to mechanically connect the flange of the sleeve 66 with the mechanical interface 70.
During maintenance of one of the connections 63, 64 between an internal tube and the internal junction 62, for example in the event of a leak, the corresponding fastener is removed between the mechanical interface 70 and the flange of the corresponding sleeve. The sleeve is translated to allow access to the connection 63, 64 so that personnel can easily work on the connection without having to disassemble numerous elements of the fluid transport circuit.
In the two embodiments shown, the fastening device 10 is therefore used to support the two portions 23, 42 of the fluid transport circuit and to guarantee a predetermined space between the two tubes 21, 22, 43, 44 of the two portions 23, 42 of the fluid transport circuit.
| Number | Date | Country | Kind |
|---|---|---|---|
| 11 60929 | Nov 2011 | FR | national |
