AIRCRAFT PROPULSION SYSTEM COMPRISING A NACELLE EQUIPPED WITH AN IMPROVED ARTICULATION SYSTEM

Abstract

AIRCRAFT PROPULSION SYSTEM COMPRISING A NACELLE EQUIPPED WITH AN IMPROVED ARTICULATION SYSTEM The invention relates to a propulsion system comprising a frame (402), two fan cowls (208a-b), and for each cowl, an articulation system (300) fixed between the frame (402) and the fan cowl (208a-b), so as to move said fan cowl (208a-b) between a closed position and an open position, and a locking means, wherein each articulation system (300) comprises, for each fan cowl (208a-b), two pantograph hinges (302). With such an arrangement, each fan cowl moves laterally apart from the beginning of its opening, which allows the two fan cowls to be separated and limits the risk of interaction. Fig. 4

Description

Title of the invention: AIRCRAFT PROPULSION SYSTEM COMPRISING A NACELLE EQUIPPED WITH AN IMPROVED ARTICULATION SYSTEM Technical field

[0001] The present invention relates to an aircraft propulsion system comprising a chassis, a nacelle with two fan cowls and, for each, an articulation system mounted on the chassis for articulating the fan cowl. The invention also relates to an aircraft comprising such a propulsion system. STATE OF THE PRIOR ART

[0002] An aircraft has a fuselage on each side of which a wing is attached. Under each wing is suspended at least one propulsion system such as a dual-flow turbojet engine. Each propulsion system has a frame, a core which constitutes the engine and a nacelle which surrounds the core, where the core and the nacelle are attached to the frame.

[0003] The propulsion system is fixed under the wing by means of a mast which is fixed between the wing structure and the chassis.

[0004] The nacelle comprises, among other things, cowls mounted on the frame and, in the case of a dual-flow turbojet, the nacelle comprises, from front to rear, an air inlet cowl, two fan cowls and rear cowls. The air inlet cowl delimits the nacelle inlet through which the air which feeds the core is introduced. The fan cowls surround a fan which draws air from the nacelle inlet to send it to the core. The rear cowls cover the rear of the core up to the exhaust nozzle.

[0005] The two fan cowls are mounted articulated on the chassis by means of hinges whose axes are generally parallel to the longitudinal axis of the propulsion system.

[0006] Although such an arrangement is satisfactory, it may happen that interactions appear between the two fan cowls when they are opened simultaneously.

[0007] It is therefore necessary to find an arrangement which makes it possible to prevent, among other things, these interactions. Statement of the invention

[0008] An object of the present invention is to provide an aircraft propulsion system comprising a chassis, a nacelle with two fan cowls and for each, an articulation system mounted on the chassis for articulating the fan cowl, where the articulation system comprises two pantograph hinges.

[0009] To this end, a propulsion system for an aircraft is proposed, said propulsion system having a longitudinal axis and comprising:

[0010] - a chassis,

[0011] - a nacelle comprising two fan cowls,

[0012] - for each fan cowl, a hinge system fixed between the chassis and said fan cowl, so as to move said fan cowl between a closed position and an open position and vice versa, and

[0013] - for each fan cowl, a locking means arranged to take al alternatively a locked position in which it ensures the locking of said fan cover on the chassis in the closed position and an unlocked position in which it does not ensure the locking of said fan cover on the chassis,

[0014] where each articulation system comprises for each fan cowl, two pantograph hinges.

[0015] With such an arrangement, each fan cowl moves laterally apart from the start of its opening, which allows the two fan cowls to be moved apart and limits the risks of interactions. In addition, such an arrangement also allows a weight saving compared to hinges of the state of the art.

[0016] Advantageously, the chassis is constituted by a fan casing of the propulsion system.

[0017] Advantageously, each pantograph hinge comprises:

[0018] - a support fixed to the chassis,

[0019] - a fitting secured to the fan cowl,

[0020] - a first arm, a first end of which is mounted articulated on the support at level of a first articulation and of which a second end is mounted articulated on the fitting at the level of a second articulation,

[0021] - an elbow mounted articulated on the support at a third joint and a second arm, a first end of which is mounted articulated on the elbow at a fourth articulation and a second end of which is mounted articulated on the fitting at a fifth articulation, and

[0022] - a connecting arm, one end of which is fixed to the first arm of the other side of the first joint relative to the second joint and a second end of which is fixed to the elbow on the other side of the third joint relative to the fourth joint.

[0023] Advantageously, each articulation is a rotation around an axis of rotation parallel to the longitudinal axis.

[0024] Advantageously, for two pantograph hinges fixed to two different fan cowls, the first arms of the pantograph hinges are arranged next to each other, and the second arms of the pantograph hinges are arranged at the opposite of each other.

[0025] Advantageously, the locking means consists of clamping screws which ensure the locking of said fan cowl on the chassis in the closed position.

[0026] Advantageously, each fan cowl comprises a skin and a rigid structure on which the outer skin is fixed and the pantograph hinges are fixed to the rigid structure.

[0027] Advantageously, the propulsion system comprises, for each fan cowl, at least one holding arm, a first end of which is fixed to the chassis and a second end of which is fixed to the fan cowl.

[0028] The invention also proposes an aircraft comprising an engine and a propulsion system according to one of the preceding variants where the engine is integral with the chassis and housed inside the nacelle. Brief description of the drawings

[0029] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0030] [Fig-1] is a side view of an aircraft according to the invention,

[0031] [Fig.2] is a perspective view of a propulsion system according to the invention,

[0032] [Fig.3] is a front view of the propulsion system of [Fig.2],

[0033] [Fig.4] is a perspective view of the interior of the propulsion system in the closed position of the fan cowls,

[0034] [Fig.5] is a schematic representation of a pantograph hinge in the closed position of the fan cowl, and

[0035] [Fig.6] is a schematic representation of a pantograph hinge in the open position of the fan cowl.

[0036] DETAILED DESCRIPTION OF EMBODIMENTS

[0037] In the following description, terms relating to a position are taken with reference to an aircraft in a forward position as shown in [Fig.l].

[0038] [Fig.l] shows an aircraft 100 which comprises a fuselage 102 on each side of which is fixed a wing 104 which carries at least one propulsion system 106 such as a dual-flow turbojet which is fixed under the wing 104 by means of a mast 108.

[0039] [Fig. 2] shows the propulsion system 106 which has a nacelle 202 and a core constituting the engine 204 and housed inside the nacelle 202. The propulsion system 106 also comprises a chassis (402, [Fig. 4]) to which the engine 204 and the nacelle 202 are fixed, among other things. The engine 204 is represented here by the ejection nozzle.

[0040] In the following description, and by convention, X is the longitudinal axis of the nacelle 202 which corresponds to the longitudinal axis of the propulsion system 106 and which is parallel to the longitudinal axis of the aircraft 100 oriented here positively in the direction of advancement of the aircraft 100, Y is the horizontal transverse axis when the aircraft 100 is on the ground, and Z is the vertical axis when the aircraft 100 is on the ground, these three directions X, Y and Z being orthogonal to each other.

[0041] The arrow 107 represents the forward direction of the aircraft 100 when the propulsion systems 106 are in operation. The nacelle 202 also has a median plane XZ which is vertical and passes through the longitudinal axis X.

[0042] The nacelle 202 comprises, from front to rear, an air inlet cowl 206 which surrounds the air inlet 207, on either side of the median plane XZ, two fan cowls 208a-b and to the rear of the fan cowls 208a-b, rear cowls 210 which may be the cowls of the thrust reversers of the propulsion system 106. The air inlet cowls 206 and the rear cowls 210 are fixed to the chassis 402 by any suitable fixing means known to those skilled in the art.

[0043] The fan cowls 208a-b surround a fan 212 which is located across the inlet of the nacelle 202 which draws air from the air inlet 207 to send it to the engine 204.

[0044] Each fan cowl 208a-b is hingedly mounted on the frame 402 between a closed position, in which it is tightened around the engine 204, and an open position, in which it is spaced away from the engine 204, and vice versa. The open position provides access to the interior of the nacelle 202.

[0045] For each fan cowl 208a-b, the propulsion system 106 also comprises a locking means which is arranged to alternately take a locked position in which it ensures the locking of said fan cowl 208a-b on the chassis 402 in the closed position and an unlocked position in which it does not ensure the locking of said fan cowl 208a-b on the chassis 402, and the fan cowl 208a-b is then free to move. The transition from the locked position to the unlocked position and vice versa is carried out for example by a technician from outside the nacelle 202. The locking means may take the form of a series of clamping screws 220 which are distributed around the periphery of the fan cowl 208a-b and which are screwed onto the chassis 402 through the fan cowl 208a-b from outside the fan cowl 208a-b.

[0046] [Fig. 3] shows the propulsion system 106 with the fan cowl 208a open, i.e. the one on the port side while the one on the starboard side is closed.

[0047] To do this, the propulsion system 106 comprises, for each fan cowl 208a-b, an articulation system 300 fixed between the chassis 402 and said fan cowl 208a-b, so as to move said fan cowl 208a-b between the closed position and open position and vice versa.

[0048] Each articulation system 300 comprises two pantograph hinges 302, one of which is better seen in [Fig. 4] which represents a pantograph hinge 302 of the fan cowl 208b on the starboard side.

[0049] Each fan cowl 208a-b extends angularly over 180° around the longitudinal axis X with an upper end at 12 o'clock and a lower end at 6 o'clock and the two pantograph hinges 302 of each fan cowl 208a-b are arranged in the vicinity of the upper end at 12 o'clock so as to move into the open position by lifting the fan cowl 208a-b.

[0050] With such an arrangement, the upper ends of the fan cowls 208a-b which are joined at 12 o'clock move apart from each other at the start of opening, reducing the risk of collision between them.

[0051] There is a pantograph hinge 302 at a front portion of the fan cowl 208a-b and a pantograph hinge 302 at a rear portion of the fan cowl 208a-b along the longitudinal axis X. The two pantograph hinges 302 of the same fan cowl 208a-b are identical.

[0052] Figs. 5 and 6 show a pantograph hinge 302 respectively in the closed position and in the open position of the fan cowl 208a.

[0053] According to a particular embodiment, the frame 402 is constituted by a fan casing 402 of the propulsion system 106, where the fan casing 402 surrounds the fan 212 and is inside the nacelle 202, i.e. the fan cowls 208a-b.

[0054] Each pantograph hinge 302 comprises a support 350 fixed to the chassis 402 and a fitting 352 secured to the fan cowl 208a.

[0055] Each pantograph hinge 302 also comprises a first arm 354, a first end of which is mounted articulated on the support 350 at a first articulation 354a and a second end of which is mounted articulated on the fitting 352 at a second articulation 354b.

[0056] Each pantograph hinge 302 also comprises an elbow 356 mounted articulated on the support 350 at a third articulation 356a and a second arm 358, a first end of which is mounted articulated on the elbow 356 at a fourth articulation 358a and a second end of which is mounted articulated on the fitting 352 at a fifth articulation 358b.

[0057] Each pantograph hinge 302 also comprises a connecting arm 360, a first end of which is fixed to the first arm 354 on the other side of the first articulation 354a relative to the second articulation 354b and a second end of which is fixed to the elbow 356 on the other side of the third articulation 356a relative to the fourth articulation 358a.

[0058] In the embodiment of the invention provided herein, the first and second arms 354 and 358 remain generally parallel between the open position and the closed position.

[0059] Each pantograph hinge 302 is generally inscribed in a plane perpendicular to the longitudinal axis X.

[0060] Each articulation 354a-b, 356a, 358a-b involved in each pantograph hinge 302 is a rotation around an axis of rotation parallel to the longitudinal axis X.

[0061] For two pantograph hinges 302 attached to two different fan cowls 208a-b, the first arms 354 of the pantograph hinges 302 are arranged next to each other, and the second arms 358 of the pantograph hinges 302 are arranged opposite each other, i.e. the pantograph hinges 302 of one fan cowl 208a-b are symmetrical to the pantograph hinges 302 of the other fan cowl 208b-a with respect to the median plane XZ.

[0062] According to the particular embodiment described here, the fixing of each fan cowl 208a-b in the closed position is carried out by the clamping screws 220 which constitute the locking means and which fix said fan cowl 208a-b on the chassis 402. Such fixing ensures control of the clearances between the fan cowl 208a-b and the surrounding cowls. The clamping screws 220 ensure the locking of the fan cowl 208a-b on the chassis 402 in the closed position.

[0063] In the embodiment of the invention shown in [Fig. 4], each fan cowl 208a-b comprises a skin 410 having an outer face facing outwards and an inner face facing away from it and a rigid structure 412 to which the outer skin 410 is fixed via its inner face. The pantograph hinges 302 are fixed to the rigid structure 412 by any suitable means such as welding, riveting, screwing, etc.

[0064] In the embodiment of the invention presented here, the rigid structure 412 is made up of two arcuate reinforcements 412a and several longitudinal reinforcements 412b.

[0065] Each arcuate reinforcement 412a is in an arc of a circle around the longitudinal axis X and there is one disposed at the front of the fan cowl 208a-b and one at the rear of the fan cowl 208a-b relative to the longitudinal axis X.

[0066] The longitudinal reinforcements 412b extend parallel to the longitudinal axis X and are fixed to the arcuate reinforcements 412a.

[0067] In this embodiment, each pantograph hinge 302 is attached to one of the arched reinforcements 412a.

[0068] To ensure that the fan cowl 208a-b is kept in the open position when the locking means is in the unlocked position, the propulsion system 106 comprises, for each fan cowl 106, at least one holding arm 307, of which a first end is fixed to the frame 402 and a second end of which is fixed to the fan cowl 208a-b. The holding arm 307 is for example a telescopic arm which unfolds manually or hydraulically.

[0069] The invention has been more particularly described in the case where the two fan cowls 208a-b are joined at 12 o'clock, but it is possible to provide that the two fan cowls 208a-b are spaced from each other and that an intermediate cowl fixed to the frame 402 is inserted between them. The operation remains identical and makes it possible to separate the fan cowl 208a-b from the intermediate cowl.

Claims

Claims

1. A propulsion system (106) for an aircraft (100), said propulsion system (106) having a longitudinal axis (X) and comprising: - a chassis (402), - a nacelle (202) comprising two fan cowls (208a-b), - for each fan cowl (208a-b), an articulation system (300) fixed between the chassis (402) and said fan cowl (208a-b), so as to move said fan cowl (208a-b) between a closed position and an open position and vice versa, and - for each fan cowl (208a-b), a locking means arranged to alternately take a locked position in which it ensures the locking of said fan cowl (208a-b) on the chassis (402) in the closed position and an unlocked position in which it does not ensure the locking of said fan cowl (208a-b) on the chassis (402), where each articulation system (300) comprises for each fan cowl (208a-b),two pantograph hinges (302).,

2. Propulsion system (106) according to claim 1, characterized in that the frame (402) is constituted by a fan casing (402) of the propulsion system (106).

3. Propulsion system (106) according to one of claims 1 or 2, characterized in that each pantograph hinge (302) comprises: - a support (350) fixed to the chassis (402), - a fitting (352) integral with the fan cowl (208a-b), - a first arm (354) of which a first end is mounted articulated on the support (350) at a first articulation (354a) and of which a second end is mounted articulated on the fitting (352) at a second articulation (354b), - an elbow (356) mounted articulated on the support (350) at a third articulation (356a) and a second arm (358) of which a first end is mounted articulated on the elbow (356) at a fourth articulation (358a) and of which a second end is mounted articulated on the fitting (352) at the level of a fifth joint (358b),and - a connecting arm (360) a first end of which is fixed to the first arm (354) on the other side of the first articulation (354a) relative to the second articulation (354b) and a second end of which, end is fixed to the elbow (356) on the other side of the third joint (356a) relative to the fourth joint (358a).

4. Propulsion system (106) according to claim 3, characterized in that each articulation (354a-b, 356a, 358a-b) is a rotation about an axis of rotation parallel to the longitudinal axis (X).

5. Propulsion system (106) according to one of claims 3 or 4, characterized in that for two pantograph hinges (302) fixed to two different fan cowls (208a-b), the first arms (354) of the pantograph hinges (302) are arranged next to each other, and the second arms (358) of the pantograph hinges (302) are arranged opposite each other.

6. Propulsion system (106) according to one of claims 1 to 5, characterized in that the locking means consists of clamping screws (220) which ensure the locking of said fan cowl (208a-b) on the chassis (402) in the closed position.

7. Propulsion system (106) according to one of claims 1 to 6, characterized in that each fan cowl (208a-b) comprises a skin (410) and a rigid structure (412) on which the outer skin (410) is fixed and in that the pantograph hinges (302) are fixed to the rigid structure (412).

8. Propulsion system (106) according to one of claims 1 to 7, characterized in that it comprises, for each fan cowl (106), at least one holding arm (307), a first end of which is fixed to the chassis (402) and a second end of which is fixed to the fan cowl (208a-b).

9. Aircraft (100) comprising an engine (204) and a propulsion system according to one of the preceding claims, wherein the engine (204) is integral with the chassis (402) and housed inside the nacelle (202).

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