Aircraft pylon comprising a tubular primary structure including at least one twin-walled pipe, and aircraft comprising at least one such pylon

An aircraft pylon comprising a primary structure and a pipe segment having an internal duct positioned inside at least one structural tube primary structure. This solution makes it possible to reduce the crowding outside the structural tubes of the primary structure, makes it easier to integrate other equipment inside the pylon, and may help to improve the aerodynamic performance of the pylon by reducing its cross section.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of the French patent application No. 2102383 filed on Mar. 11, 2021, the entire disclosures of which are incorporated herein by way of reference.

FIELD OF THE INVENTION

The present application relates to an aircraft pylon comprising a tubular primary structure that includes at least one twin-walled pipe, and to an aircraft comprising at least one such pylon.

BACKGROUND OF THE INVENTION

According to one embodiment, shown inFIG.1, an aircraft10comprises a fuselage12, at least one wing14connected to the fuselage12, and propulsion units16positioned beneath the wings14.

Each propulsion unit16is connected to the wing14by a pylon18which comprises a primary structure which serves, among other things, to react the forces between the propulsion unit16and the wing14, and a secondary structure forming an outer aerodynamic fairing in which the primary structure is positioned.

According to one embodiment, the primary structure is a box-type structure delimited by upper and lower lateral panels inside which are housed numerous elements connecting each propulsion unit to the rest of the aircraft, such as a fuel pipe.

In the case of a propulsion unit running on hydrogen, the pipes must be twin-walled pipes and comprise an internal duct in which the hydrogen flows, and an external duct inside which the internal duct is positioned substantially coaxially. A pipe of this kind is relatively bulky, which makes it difficult to integrate into the pylon and also tends to increase the cross section of the pylon and hence to reduce the aerodynamic performance of the aircraft.

The present invention aims to remedy all of part of the drawbacks of the prior art.

SUMMARY OF THE INVENTION

To that end, the invention relates to an aircraft pylon comprising a primary structure comprising structural tubes and a pipe segment having an internal duct, each structural tube comprising a tubular wall that separates an interior zone from an exterior zone.

According to the invention, the internal duct of the pipe segment is positioned in the interior zone of at least one of the structural tubes of the primary structure.

This solution makes it possible to reduce the crowding outside the structural tubes of the primary structure, makes it easier to integrate other equipment inside the pylon, and may help to improve the aerodynamic performance of the pylon by reducing its cross section.

According to another feature, the primary structure comprises at least one first or second passage hole passing through at least one of the tubular walls of the structural tubes of the primary structure, the first or second passage hole being configured to allow the internal duct to pass therethrough.

According to another feature, the primary structure comprises a first passage hole for the internal duct to pass into the interior zone of at least one of the structural tubes of the primary structure, and a second passage hole for the internal duct to pass out of the interior zone.

According to another feature, the pylon comprises an upstream and/or downstream pipe segment comprising an external duct which forms, with the internal duct, a twin-walled pipe, the external duct comprising an end oriented towards one of the structural tubes of the primary structure. In addition, the pylon comprises a leaktight connection connecting the end of the external duct and one of the structural tubes of the primary structure.

According to another feature, the connection comprises:

an end wall fitted to the end of the external duct and held clamped against the tubular wall of the structural tube all around the first or second passage hole, this end wall having a passage orifice through which the internal duct passes,

a tubular extension that prolongs the passage orifice and is push-fitted into the first or second passage hole,

at least one first seal, surrounding the first or second passage hole, interposed between the end wall and the tubular wall (P30, P34) of the structural tube,

at least one second seal interposed between the internal duct and the tubular extension.

According to another feature, the pylon comprises a sealing system between the internal duct and the tubular wall of the structural tube at the first or second passage hole. This sealing system comprises a collar that is secured to the internal duct and positioned outside the structural tube and held clamped against the tubular wall of the structural tube all around the first or second passage hole, and at least one seal which surrounds the first or second passage hole and is interposed between the collar and the tubular wall of the structural tube.

According to another feature, the pylon comprises at least two internal duct segments, a connector connecting the two internal duct segments, first and second structural tube segments and a connection system connecting the first and second structural tube segments, the connector and the connection system being positioned approximately in a shared plane. This connection system comprises two ends of the first and second structural tube segments push-fitted one inside the other, a system for holding the two ends push-fitted one inside the other and at least one seal interposed between the two ends push-fitted one inside the other.

According to another feature, the primary structure comprises a transverse frame comprising an orifice in which are positioned the connector and the connection system. In addition, the holding system comprises a first collar secured to the first structural tube segment and held clamped against a first face of the transverse frame, a second collar secured to the second structural tube segment and held clamped against a second face of the transverse frame, and sealing elements interposed between each of the first and second collars and the transverse frame.

According to another feature, the primary structure comprises at least one partition which is positioned inside one of the structural tubes and is connected in a leaktight manner to the tubular wall so as to delimit, in the interior zone, a leaktight cavity in which the internal duct is positioned.

According to another feature, the primary structure comprises at least one spacer that is configured to keep separate the internal duct and the tubular wall of the structural tube.

The invention also relates to an aircraft comprising at least one pylon according to one of the preceding features.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown inFIG.2, an aircraft20comprises at least one wing22, at least one engine24having a propeller, and at least one pylon26connecting the engine24to the wing22.

For the remainder of the description, the longitudinal direction is parallel to the engine axis A24. A transverse plane is perpendicular to the longitudinal direction or to the engine axis A24.

The pylon26comprises a primary structure28and a secondary structure, forming an aerodynamic fairing around the primary structure28. The primary structure comprises an engine mount28.1for connecting it to the engine24and a wing mount28.2for connecting it to the wing22.

The primary structure28is a tubular structure and comprises a plurality of structural tubes30,32,34.

A structural tube is understood to be a tube that is designed to transmit some of the forces between the engine24and the rest of the aircraft20.

According to one embodiment, the structural tubes30,32,34are arranged in a truss, and the primary structure28comprises hoops36positioned in transverse planes and connected to one another by the structural tubes30,32,34.

Each structural tube30,32,34comprises a tubular wall P30, P32, P34that separates an interior zone Zi from an exterior zone Ze.

According to one configuration shown inFIGS.4and5, the primary structure28comprises:

a first structural tube30which extends between a first end30.1close to the wing22and a second end30.2close to the engine24,

a second structural tube32which extends between a first end32.1connected to the first end30.1of the first structural tube30and a second end32.2remote from the second end30.2of the first structural tube30,

a third structural tube34which has a first end34.1connected the first ends30.1,32.1of the first and second structural tubes30,32and which runs alongside the wing mount28.2.

The first, second and third structural tubes30,32,34form a Y shape, the third structural tube34forming the stem of the Y shape and the first and second structural tubes30,32forming a V shape. According to this configuration, the first, second and third structural tubes30,32,34are connected at a node38corresponding to the first ends30.1,32.1,34.1of the first, second and third structural tubes30,32,34. At the node38, the interior zones ZI of the first, second and third structural tubes30,32,34communicate with one another, as shown inFIG.9.

The aircraft20also comprises at least one reservoir39and at least one pipe connecting the reservoir39to the engine24.

According to one configuration, this pipe comprises a first pipe segment40upstream of the pylon26, a second pipe segment42downstream of the pylon26and a third pipe segment44positioned at the pylon26.

Whatever the configuration, the pylon26comprises at least one pipe segment44.

According to one particular aspect of the invention, the pipe segment44comprises an internal duct46positioned in the interior zone of at least one structural tube30,32,34of the primary structure28. Thus, the internal duct46and the structural tube30,32,34form a twin-walled pipe.

According to one configuration, the internal duct46enters the interior zone Zi of the structural tube30,32,34, or exits therefrom, via at least one opening end of the structural tube30,32,34. According to another configuration, the primary structure28comprises at least one passage hole48that passes through at least one of the tubular walls P30, P32, P34of the structural tubes30,32,34of the primary structure28, the passage hole48being configured in such a way that the internal duct46can pass through it. According to one embodiment shown inFIGS.4to8, the primary structure28comprises a first passage hole48that serves for the internal duct46to enter the interior zone Zi of at least one of the structural tubes30,32,34of the primary structure28, and a second passage hole48′ to allow it to leave the interior zone Zi.

According to a first configuration, shown inFIG.4, the internal duct46follows a path inside the first structural tube30, between a first passage hole48positioned close to the first end30.1of the first structural tube30and a second passage hole48′ positioned close to the second end30.2of the first structural tube30.

According to a second configuration, shown inFIG.5, the internal duct46follows a path inside the first and third structural tubes30,34, between a first passage hole48positioned close to the second end34.2of the third structural tube34and a second passage orifice48′ positioned close to the second end30.2of the first structural tube30.

According to one configuration, the internal duct46is configured to convey hydrogen. Depending on circumstances, it may comprise a single segment that extends from the reservoir39to the engine24, or multiple segments that are connected to one another by at least one connector50, as illustrated inFIG.9.

According to one embodiment, the pylon comprises at least two internal duct segments46,46′, with a connector50connecting the two internal duct segments46,46′, two structural tube segments34,34′ and a connection system52connecting the two structural tube segments34,34′, the connector50and the connection system52being positioned approximately in a shared plane.

According to one configuration, shown inFIG.9, the first structural tube segment34corresponds to the third structural tube34. The second structural tube segment34′ extends the first ends30.1,32.1of the first and second structural tubes30,32so as to obtain a Y shape.

As illustrated inFIG.9, the connection system52comprises two ends54,54′ of the structural tube segments34,34′, these ends being push-fitted one inside the other, a system for holding the two ends54,54′ of the structural tube segments34,34′ push-fitted one inside the other, and at least one seal56interposed between the two ends54,54′ of the structural tube segments34,34′ push-fitted one inside the other.

According to this embodiment, the connector50connecting the two internal duct segments46,46′ is a quick connector that serves to establish a connection without the need for tools.

This arrangement makes it possible to obtain a removable connection for the pipe segment44at the pylon26, which makes it easier to install and remove the engine24.

According to one configuration, the primary structure28comprises a transverse frame58which has an orifice60in which the connector50and the connection system52are positioned. In addition, the holding system comprises a first collar62that is secured to the first structural tube segment34and is held clamped against a first face58.1of the transverse frame58, a second collar64that is secured to the second structural tube segment34′ and is held clamped against a second face58.2(opposite the first face58.1) of the transverse frame58, and sealing elements66interposed between each of the first and second collars62,64and the transverse frame58.

The connection system52comprises fasteners68for connecting the first and second collars62and64to the transverse frame58. To that end, the first and second collars62,64comprise orifices70for accommodating the fasteners68. For at least one of the first and second collars62,64, the fasteners68and the orifices70are configured to allow a slight degree of play in a plane parallel to the first or second face58.1,58.2of the transverse frame58.

According to one embodiment, the primary structure28comprises at least one spacer72that is configured to hold the internal duct46and the tubular wall P34of the structural tube34apart, as illustrated inFIG.9.

According to one embodiment, shown inFIGS.6to9, the primary structure28comprises at least one partition74, positioned inside one of the structural tubes30,32,34and connected in a leaktight manner to the tubular wall P30, P32, P34in order to delimit, in the interior zone Zi, a leaktight cavity Z1in which the internal duct46is positioned.

According to one configuration, the primary structure28comprises a first partition74(shown inFIG.7) positioned in the third structural tube34, close to the first passage hole48, a second partition74′ (shown inFIGS.6and8) positioned in the first structural tube30, close to the second passage hole48′, and a third partition74″ positioned in the second structural tube32, close to its first end32.1. These partitions74,74′,74″ serve to delimit, together with the tubular walls P30, P32, P34, a leaktight cavity Z1.

The cavity Z1, which contains the internal duct46and is isolated by at least one partition74,74′,74″, can be filled with an inert gas or a foam, or can be evacuated.

According to one configuration, shown inFIGS.6and7, the upstream and/or downstream pipe segment40,42comprises an external duct76to form, with the internal duct46, a twin-walled pipe. Each external duct76comprises an end76.1connected by a leaktight connection78to one of the structural tubes30,34of the primary structure28.

According to embodiments shown inFIGS.6and7, this connection78comprises an end wall80attached to the end76.1of the external duct76and held clamped against the tubular wall P30, P34of the structural tube30,34all around the first or second passage hole48,48′. This end wall80comprises a passage orifice82through which the internal duct46passes.

The connection78comprises a tubular extension84that extends the passage orifice82and is push-fitted into the first or second passage hole48,48′. This tubular extension84has an internal diameter that is substantially equal to or slightly greater than the external diameter of the internal duct46. The connection78comprises fasteners86connecting the end wall80to the tubular wall P30, P34of the structural tube30,34, at least one first seal88that surrounds the first or second passage hole48,48′ and is interposed between the end wall80and the tubular wall P30, P34of the structural tube30,34, and at least one second seal90interposed between the internal duct46and the tubular extension84.

According to one configuration, shown inFIG.8, the upstream or downstream pipe segment40,42of the pipe does not comprise an external duct. In this case, the pylon comprises a sealing system between the internal duct46and the tubular wall P30, P34of the structural tube30,34at the first or second passage hole48,48′. This sealing system comprises a collar92that is secured to the internal duct46and positioned outside the structural tube30,34and held clamped against the tubular wall P30, P34of the structural tube30,34all around the first or second passage hole48,48′, and at least one seal96surrounding the first or second passage hole48,48′, interposed between the collar92and the tubular wall P30, P34of the structural tube30,34. The sealing system also comprises fasteners94that serve to connect the collar92and the tubular wall P30, P34of the structural tube30,34.

The invention is not restricted to the embodiments described in relation to the engine24, the manner of fastening the engine24and the fluid flowing in the pipe. In other words, the engine24might not have a propeller and might be connected to a different part of the aircraft20, such as a fuselage. Furthermore, the invention is not restricted to hydrogen and may be suitable for any type of fluid.

Whatever the embodiment, at least one structural tube30,32,34of the primary structure28is used as an external duct of a pipe. This solution makes it possible to integrate at least one duct inside at least one structural tube, which serves to reduce the crowding outside the structural tubes of the primary structure, makes it easier to integrate other equipment inside the pylon, and may help to improve the aerodynamic performance of the pylon by reducing its cross section.

Furthermore, the fact that a single element acts both as a structural tube and as an external duct of a pipe helps to reduce the on-board mass.