AIRCRAFT HAVING AN ENGINE PYLON WITH A MOBILE COWL

An aircraft having a fixed structure, an engine pylon, and a cowling system, a slider bearing a rear cowl and able to move in translation from an advanced position to a retracted position, a displacement system having, on either side of a median plane of the engine pylon, a guide as one with the fixed structure, a sliding element as one with the slider and sliding along each guide disposed on the same side, and a support as one with the fixed structure and having a blade parallel to the translation direction and on which a surface parallel to the translation direction of the slider rests. The presence of the mobile cowl ensures, inter alia, easy access to the inside of the engine pylon and to the systems that are housed therein.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of the French patent application No. 2213828 filed on Dec. 19, 2022, the entire disclosures of which are incorporated herein by way of reference.

FIELD OF THE INVENTION

The present invention relates to an aircraft having an engine pylon with a mobile cowl allowing access to the inside of the engine pylon.

BACKGROUND OF THE INVENTION

An aircraft conventionally has an engine, for example a jet engine, which is fastened beneath a wing of the aircraft using an engine pylon. The engine pylon is constituted of a rigid structure that is fastened both to a structure of the wing and to a structure of the engine. The engine pylon allows the transmission of the forces generated by the engine to the structure of the wing, when the engine is running. The engine pylon also allows systems to pass between the wing and the engine, such as, for example, the electrical system, the hydraulic system, pneumatic system, etc.

In order to limit the drag of the engine pylon, it is covered with a set of cowls. The cowls are positioned next to one another so as to create a surface that is as smooth as possible, and are fastened either to the structure of the engine pylon or to the structure of the wing of the airplane.

In order to access the inside of the engine pylon, removable hatches are provided on some of these cowls. The hatches are fastened by threaded fasteners or rivets and, after removal, a technician can access the inside of the engine pylon and thus perform maintenance on the elements that are present.

The fastening of the cowls requires the presence of a structure that is relatively rigid and therefore heavy. Furthermore, as a result of the manufacturing and assembly tolerances, a plurality of cowls cannot be juxtaposed next to one another without the appearance of spaces and discontinuities between these cowls. These spaces and discontinuities can cause disruption of the flow of the air and the occurrence of acoustic phenomena. Finally, the removal of the hatches does not allow easy access to the inside of the engine pylon and their presence makes it necessary to put in place local structural reinforcing elements.

SUMMARY OF THE INVENTION

An object of the present invention is thus to propose an aircraft having an engine pylon with a mobile cowl. Such a mobile cowl allows easy access to the engine pylon and to the systems that are included therein, in particular for maintenance and inspection tasks, and the structure supporting this mobile cowl is simplified with respect to a structure of the prior art. Furthermore, this mobile cowl can be made in one piece, which in turn reduces the disruption of the flow of the air and the occurrence of acoustic phenomena.

To this end, there is proposed an aircraft having a fixed structure, a wing, an engine and an engine pylon fastened between the wing and the engine, the engine pylon having a primary structure intended to fasten the engine and the wing to each other, and a cowling system having:a front set of cowls, wherein the cowls are fastened around the primary structure,a slider bearing a mobile rear cowl disposed in the continuation of and at the rear of the front set of cowls, wherein the slider is able to move in translation parallel to a translation direction from an advanced position, in which the mobile rear cowl is in the continuation of and at the rear of the front set of cowls, to a retracted position, in which the mobile rear cowl is moved away, towards the rear, from the front set of cowls,a displacement system arranged to move the slider and having, on either side of a median plane of the engine pylon, at least one guide as one with the fixed structure at a rear part of the mobile rear cowl in the closed (advanced) position, for each at least one guide, a sliding element as one with the slider and mounted so as to be able to slide along each guide disposed on the same side so as to realize a sliding connection, and, for each sliding element, a support as one with the fixed structure and having a blade parallel to the translation direction and on which a surface parallel to the translation direction of the slider rests, wherein each support is disposed at the front of the guides and generally in the middle of the sliding element when the slider is in the advanced position, andan immobilizing system alternately adopting a locked position in which it immobilizes the slider in the advanced position, and an unlocked position in which it does not immobilize the slider.

The presence of the mobile cowl and its displacement system ensures easy access to the inside of the engine pylon and to the systems that are housed therein and easy displacement of the mobile cowl.

Advantageously, each sliding element has a cylinder parallel to the translation direction of which the length is at least equal to the length of displacement of the slider, and each guide has a bore parallel to the translation direction in which the cylinder is mounted so as to be able to slide.

Advantageously, the fixed structure has a bottom front centering pin and the slider has a first housing in which the bottom front centering pin is housed when the slider arrives in the advanced position, wherein the first housing is disposed at the median plane and in the bottom part and at the front of the mobile rear cowl.

Advantageously, the slider has two top front centering pins disposed on either side of the median plane and in the top part and at the front of the mobile rear cowl, and the fixed structure has, for each top front centering pin, a second housing in which the top front centering pin is housed when the slider arrives in the advanced position.

Advantageously, the slider has two rear centering pins disposed on either side of the median plane and in the top part and near the guides in the advanced position, and the fixed structure has, for each rear centering pin, a third housing in which the rear centering pin is housed when the slider arrives in the advanced position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG.1shows an aircraft10that has an engine14, for example a jet engine, and a wing12beneath which the engine14is fastened via an engine pylon100. The aircraft10has a fixed structure50that can encompass the structure of the wing12and the structure of the engine14.

In the following description, terms relating to a position are considered in relation to an aircraft10in a normal flight position, i.e., as shown inFIG.1, and the “front” and “rear” positions are considered relative to the front and the rear of the engine14and relative to the direction of forward movement F of the aircraft10when the engine14is in operation.

In the following description, and by convention, the X direction is the longitudinal direction of the engine14, which is parallel to the longitudinal axis of the jet engine, the Y direction is the transverse direction, which is horizontal when the aircraft10is on the ground, and the Z direction is the vertical direction, which is vertical when the aircraft10is on the ground, these three directions X, Y and Z being mutually orthogonal.

FIG.2shows the wing12and the engine14fastened to one another via the engine pylon100that has a front set of cowls202,203and a rear cowl204.

In the embodiment of the invention that is presented here, the rear cowl204is divided into a mobile rear cowl204ain the bottom part and a fixed rear cowl204bin the top part between the mobile rear cowl204aand the wing12. The fixed rear cowl204bis as one with the pressure-side panel of the wing12and can be considered to form part of the wing12.

In another embodiment of the invention (not shown), the rear cowl204is limited to the mobile rear cowl204athat comes directly against the pressure-side panel of the wing12.

In the embodiment of the invention that is presented here, the front set of cowls has a front cowl202and an intermediate cowl203disposed at the rear of the front cowl202, but in another embodiment, the front cowl202and the intermediate cowl203can constitute just a single cowl.

The mobile rear cowl204ais disposed at the rear of the front set of cowls202,203.

In this case, the mobile rear cowl204ais disposed beneath the wing12and at the rear of the engine14and the front cowl202is disposed above the engine14and in front of the wing12. The intermediate cowl203forms the junction between the front cowl202and the rear cowl204.

FIG.3shows the engine pylon100having a slider52on which the mobile rear cowl204ais fastened. In the embodiment of the invention that is presented in

FIG.3, the slider52is constituted of vertical ribs52a-cand horizontal stiffeners52d-ethat are fastened to each other and the mobile rear cowl204ais fastened around the slider52so as to cover it.

FIG.3shows the engine pylon100with the slider52and the mobile rear cowl204ain the closed and advanced position, the latter being shown as transparent. The slider52is arranged so as to pass from the closed and advanced position to an open and retracted position and vice versa, wherein the slider52and the mobile rear cowl204aare moved in translation parallel to a translation direction T generally parallel to the longitudinal direction X.

The engine pylon100comprises a rigid structure302, also called primary structure, which is intended to be fastened between a structure of the engine14and a structure of the wing12, such as, in particular, the front spar of the wing12that extends generally in the transverse direction Y. The rigid structure302does not constitute an essential element of the invention, and it can take various forms.

The primary structure302supports the engine14via fastening means (not illustrated) that are disposed generally at the front and at the rear of the primary structure302and take, for example, the form of those disclosed in the document US-A-2016/0221682.

The primary structure302is embodied here by a rear rib.

The primary structure302is fastened to the wing12, for example, by sets of shackles.

In the embodiment of the invention that is presented here, the engine pylon100also has, at the rear of the primary structure302, a rear clevis60as one with the primary structure302. The primary structure302is fastened to the wing12inter alia via a rear rod62that connects, in use, the rear clevis60to an upper clevis64of the wing12.

The rear rod62has a first end mounted in an articulated manner on the rear clevis60and a second end mounted in an articulated manner on the upper clevis64, in particular, at the pressure-side panel of the wing12.

In the embodiment of the invention that is presented here, the cowls202and203of the front set of cowls202,203are fastened around the primary structure302, i.e., the primary structure302is housed at least in part in the front set of cowls202,203.

In the particular embodiment presented here, the rear rod62is housed inside the rear cowl204. Of course, depending on the design of the engine pylon100, the arrangement may be different.

The front cowl202and the intermediate cowl203are fastened to the primary structure302by any appropriate fastening means such as, for example, support elements, fittings and held by means of threaded means or rivets.

The engine pylon100thus has a cowling system200that has the front set of cowls202,203and the slider52incorporating the mobile rear cowl204a.

The cowling system200also has a displacement system250that moves the slider52and the mobile rear cowl204ain translation parallel to the translation direction T from the closed/advanced position, in which the mobile rear cowl204ais in contact, on its front face, with the intermediate cowl203and extends in the continuation of and at the rear of the front set of cowls202,203and, more particularly in this case, the intermediate cowl203, to the open/retracted position, in which the mobile rear cowl204ais retracted relative to its advanced position, so as to be moved away, towards the rear, from the front set of cowls202,203and, more particularly in this case, from the intermediate cowl203, and thus to free up a space between the front set of cowls202,203and the mobile rear cowl204aso as to allow access to the inside of the engine pylon100and to the various systems that are housed therein (not shown in the figures in this file). The mobile rear cowl204ais thus a mobile cowl and the moving clear of the mobile rear cowl204aallows easy access compared with the hatches of the prior art. Furthermore, it is not necessary to provide access hatches, thus simplifying the structure relative to the prior art, such as, for example, with a “one-piece” external skin of the cowl, which is made in a single piece and promotes aerodynamic flow, as is shown inFIG.8that shows the mobile rear cowl204ain a single piece. The stopping of the slider52and the mobile rear cowl204ain the open/retracted position is ensured, for example, by any appropriate stopping means, such as, for example, an end-of-travel stop as one with the fixed structure50and against which an element of the slider52or of the mobile rear cowl204acomes to abut. In order to allow complete removal of the mobile rear cowl204a, the stopping means is removable.

The cowling system200also has an immobilizing system, such as a lock or latch or a threaded fastener, which can alternately adopt a locked position in which it immobilizes the slider52and the mobile rear cowl204ain the advanced position, and an unlocked position in which it does not immobilize either the slider52or the mobile rear cowl204a, and leaves them free to pass from the advanced position to the retracted position and vice versa. In the unlocked position, the slider52and the mobile rear cowl204aare therefore free to move in translation.

The immobilizing system makes it possible to fasten the slider52and/or the mobile rear cowl204ato a fixed element such as the fixed structure50, or an element of the engine pylon100, such as for example, the intermediate cowl203or the primary structure302.

FIGS.4,5,6and7show various views of the displacement system250, which is generally symmetrical with respect to a vertical median plane XZ of the engine pylon100.

The displacement system250has, on either side of the median plane XZ, at least one guide402a-bintended to guide the slider52parallel to the translation direction T and as one with the fixed structure50of the aircraft10such as, for example, the structure of the wing12. In the embodiment of the invention that is presented here, there are two guides402a-bon each side, i.e., two on the port side and two on the starboard side, and the guides402a-bare arranged at a rear part of the mobile rear cowl204awhen it is in the closed/advanced position.

The displacement system250also has, on either side of the median plane XZ, a sliding element404a-bas one with the slider52. There is thus a sliding element404aon the port side and a sliding element404bon the starboard side, and each sliding element404a-bis mounted so as to be able to slide along each guide402a-bdisposed on the same side. The length of each sliding element404a-bis such that it slides in the guides402a-bbetween the closed/advanced position and the open/retracted position.

Each guide402a-bhas a length shorter than the length of the translation undergone by the slider52, and therefore than the length of the corresponding sliding element404a-b, in order to limit the forces in the event of a lack of parallelism. The length of each guide402a-bis, for example, on the order of one third of the length of the translation.

In the embodiment of the invention that is presented here, each sliding element404a-bhas a cylinder parallel to the translation direction T of which the length is at least equal to the length of displacement of the slider52, and each guide402a-bhas a bore parallel to the translation direction T in which the cylinder is mounted so as to be able to slide. The bore has a slot through which passes the part of the slider52ensuring the junction with the cylinder. Of course, any other type of complementary shapes is possible for realizing the sliding connection parallel to the translation direction T.

The cooperation between the guides402a-band the sliding elements404a-bmoves the slider52and the mobile rear cowl204ain translation along the translation direction T, between the advanced position and the retracted position and vice versa.

Because the guides402a-bhave shorter lengths than the sliding element404a-band are disposed at the rear of the movable rear cowl204a, the displacement system250also has, for each sliding element404a-b, i.e., on either side of the median plane XZ, a support406a-bas one with the fixed structure50and having a blade408a-bparallel to the translation direction T and on which a surface of the slider52that is parallel to the translation direction T rests. Each support406a-bis disposed at the front of the guides402a-band generally in the middle of the sliding element404a-bwhen the slider52is in the closed/advanced position.

Each support406a-breacts the forces in the Z direction during the displacements of the slider52and of the mobile rear cowl204aat the beginning of the translation from the closed/advanced position. Each support406a-balso supports the slider52, avoiding jamming of the latter as a result of the overhang due to the retracted position of the guides402a-b.

In order to react forces between the slider52and the fixed structure50, the aircraft10has a plurality of positioning centering pins, wherein each one is as one with the slider52or the fixed structure50and, for each positioning centering pin, the fixed structure50or the slider52has a housing in which the positioning centering pin is housed when the slider52is in the advanced position.

In the embodiment of the invention that is presented here, there is one bottom front centering pin350, two top front centering pins352and two rear centering pins354.

The bottom front centering pin350, which is better seen inFIG.5, is secured to the fixed structure50, in this case via the rigid structure302, and it is oriented towards the rear, and the slider52, in this case a vertical rib52b, has a first housing351in which the bottom front centering pin350is housed. The first housing351is disposed at the median plane XZ and in the bottom part and at the front of the mobile rear cowl204a.

The bottom front centering pin350thus fits into the first housing351when the slider52arrives in the advanced position.

The first housing351has an oblong shape, of which the major axis is vertical and of which the width along the minor axis is adapted to the diameter of the bottom front centering pin350so as to ensure a close sliding fit. Such an arrangement makes it possible to react the transverse forces in the transverse direction Y.

The two top front centering pins352, one of which is better seen inFIG.7, are secured to the slider52, in this case via a vertical rib52b, and they are oriented towards the front and substantially parallel to the longitudinal axis of the sliding elements404a-b, and the fixed structure50has, for each top front centering pin352, a second housing353in which the top front centering pin352is housed. The two top front centering pins352are disposed on either side of the median plane XZ and in the top part and at the front of the mobile rear cowl204a.

Each top front centering pin352thus fits into the associated second housing353when the slider52arrives in the advanced position.

Each second housing353takes the form of a circular bore integrated in a clevis as one with the fixed structure50and adapted to the diameter of the associated top front centering pin352so as to ensure a close sliding fit. Such an arrangement makes it possible to react the transverse forces in the transverse direction Y and the vertical forces in the vertical direction Z.

The two rear centering pins354, one of which is better seen inFIG.6, are secured to the slider52, in this case via, successively, a vertical rib52aand blades356as one with the vertical rib52a, and they are oriented towards the front, and the fixed structure50has, for each rear centering pin354, a third housing355in which the rear centering pin354is housed. The two rear centering pins354are disposed on either side of the median plane XZ and in the top part of the mobile rear cowl204aand near the guides402a-bwhen the slider52is in the advanced position.

For reasons of clarity, the port-side blade356has been removed so as to make the third housing355and the rear centering pin354in the third housing355visible.

Each rear centering pin354thus fits into the associated third housing355when the slider52arrives in the advanced position.

Each third housing355takes the form of a circular bore integrated in a clevis as one with the structure50and adapted to the diameter of the associated rear centering pin354so as to ensure a close sliding fit. Such an arrangement makes it possible to react the transverse forces in the transverse direction Y and the vertical forces in the vertical direction Z.