LOCK FOR PROPULSION ASSEMBLY CABIN

Abstract

Lock (50) for a propulsion assembly nacelle, comprising first and second hoods (20, 22), comprising: - a first part (52) intended to be fixed to the first hood (20) and having a hook (30) and a handle (28) for actuating the hook (30), - a second part (54) intended to be fixed to the second hood (22) and having a bracket (56) having a loop (33) which is configured to cooperate with said hook (30), the first or second part (52, 54) having a threaded rod (62) and an adjusting nut (66) the tightening / loosening of which allows adjustment of the position of the loop (33) of the bracket (56) vis-à-vis the hook (30), or vice versa, the first or second part (52, 54) having an orifice (64) in which is mounted a ring (68) through which the threaded rod (62) passes, The nut and the ring are prevented from rotating relative to each other. See Figure 7 for abbreviations.

Description

Title of the invention: LOCK FOR PROPULSION UNIT NACELLE Technical field of the invention

[0001] The present invention relates to a lock for a propulsion unit nacelle, in particular an aircraft nacelle, and a nacelle equipped with such a lock. The lock is shaped to lock cowls in the closed position when it occupies a locking configuration and to allow the cowls to be opened when it occupies an unlocking configuration. Technical background

[0002] The technical background includes in particular document FR-A1-3 015 435.

[0003] Engine assemblies for aircraft generally comprise a nacelle forming a generally annular outer casing housing inside a turbomachine arranged along the longitudinal axis of this nacelle. The turbomachine receives fresh air coming from the upstream side, and discharges on the downstream side the hot gases resulting from the combustion of the fuel, which provide a certain thrust.

[0004] An aircraft turbomachine generally comprises, from upstream to downstream, a fan and several modules such as a low pressure compressor followed by a high pressure compressor, an annular combustion chamber, a high pressure turbine followed by a low pressure turbine, which drive the corresponding low or high pressure compressor, and a gas ejection system. Upstream and downstream are defined relative to the normal flow direction of the gas in a flow vein (from upstream to downstream).

[0005] In the case of dual-flow turbomachines, the high and low pressure bodies are crossed by a primary air flow and the fan produces a secondary air flow which circulates in the turbomachine, between a casing and a nacelle or external casing of the turbomachine, in a cold flow channel. At the outlet of the nozzle, the gases from the primary flow are mixed with the secondary flow to produce a propulsive force, the secondary flow here providing the majority of the thrust in normal operation giving a direct jet.

[0006] Some nacelles include a thrust reversal system which at least partially closes the annular cold air stream, and rejects the secondary flow forward, forming an inverted jet which generates a braking counter-thrust of the aircraft. A known type of nacelle includes two half-cowls or cowls covering the middle section surrounding the secondary flow fan connected to each other by a hinge having a longitudinal axis located in the upper part, so as to allow a opening the lower parts of these covers for maintenance operations.

[0007] The hoods are held in the closed position, generally in the lower part, by locks which provide tangential clamping between these two hoods.

[0008] In a known manner, these locks comprise a hook and a loop, each fixed to one of the covers. In a locking configuration of the locks, the hook cooperates with the loop in a closed position of the covers. In an unlocking position of the locks, the hook is released from the loop and allows the covers to be opened.

[0009] Locks are generally operated manually by an operating handle.

[0010] The loop is located at a longitudinal end of a threaded rod which receives a nut for adjusting the pre-tension or pre-load of the lock. This nut is screwed or unscrewed to adjust the position of the loop with respect to the hook and thus the force necessary to apply to the hook so that it locks onto the loop and unlocks from the loop, and therefore to move from the locking position to the unlocking position, and vice versa. It is necessary to ensure that this pre-load does not become disturbed, either in flight or during the various maintenance operations.

[0011] In the current technique, one solution consists of immobilizing the adjustment nut in rotation by protrusions which are carried by a part added to the lock, such as a housing, and which cooperate with housings in the flank of the nut.

[0012] Several solutions exist to ensure that the flank of the adjustment nut remains pressed against these protrusions. Springs or wavy washers can be used to press the nut against the protrusions and to sense the passage from one housing to another housing facing the protrusion(s) by bringing the nut back against it(them) in the absence of preload.

[0013] This preload adjustment nut can be located on the hook or loop side of the latch.

[0014] These solutions are however not satisfactory in particular because the engagement of the protrusions in the nut housings is difficult to detect. When adjusting the preload, it is possible that the protrusions do not fit correctly into the housings provided on the side of the nut. In this case, when closing the lock, these protrusions can be crushed and damaged, which can have an impact on the preload but also on ensuring its stability.

[0015] The objective of the present invention is thus to propose a nacelle lock making it possible to overcome at least some of these drawbacks of the prior art. Summary of the invention

[0016] To this end, the invention relates to a lock for a propulsion unit nacelle, in particular an aircraft nacelle, comprising first and second covers, the lock comprising: - a first part intended to be fixed to the first cover and comprising a hook and a handle for actuating the hook, the hook being movable from an unlocking position to a locking position, the actuating handle being connected to the hook and being movable from a closing position to an opening position, the movement of the actuating handle from its closing position to its opening position causing the movement of the hook from its locking position to its unlocking position, and vice versa, and

[0017] - a second part intended to be fixed to the second cover and comprising a stirrup comprising a loop which is configured to cooperate with said hook,

[0018] the first or second part comprising a threaded rod which is connected to said hook or to said loop, this threaded rod receiving an adjustment nut whose screwing / unscrewing makes it possible to adjust the position of the loop of the stirrup with respect to the hook, or vice versa, the first or second part comprising an orifice in which is mounted a ring crossed by the threaded rod, this ring comprising an external annular collar of which an annular face is capable of bearing on an annular face of the adjustment nut,

[0019] the hook being adapted to engage the loop of the stirrup when the hook is moved from its unlocking position to its locking position, and to disengage from the loop of the stirrup when the hook is moved from its locking position to its unlocking position,

[0020] characterized in that one of the faces chosen from the annular face of the collar and the annular face of the nut comprises a number of projections, and the other of these faces comprises the same number of holes, said projections all being intended to be engaged in said holes when the faces are bearing on each other, so as to secure the nut and the ring in rotation.

[0021] The invention thus proposes to provide the means for immobilizing the nut directly on the ring on which the nut is intended to bear. This is advantageous because it is not necessary to provide an additional part such as a housing to immobilize the nut in rotation. The lock is therefore simpler and less expensive to manufacture. Furthermore, the cooperation of the ring with the nut is more easily visible and therefore a lack of cooperation can be easily identified by an operator, for example when the nut is moved away from the ring and is no longer bearing on it.

[0022] The number of projections is equal to the number of holes, which is advantageous because it guarantees that the nut is properly immobilized in rotation, even if some of the projections are damaged, for example after several cycles of use and opening / closing of the lock.

[0023] This number is determined to both make the rotation locking function more reliable and also to better distribute the rotation locking force, thus limiting the risk of damage to the projections.

[0024] The lock according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another in all technically possible combinations:

[0025] - the projections are bosses, teeth, crenellations, chevrons, pawns, fingers, bosses, etc.;

[0026] - the holes have shapes complementary to the projections, preferably with clearance; - the said number of projections is between 8 and 20; - each of the projections has a spherical cap shape; - the holes are blind holes of a shape complementary to the projections; - said ring mounting hole is formed in a tab of a support integral with the corresponding cover or formed in a single piece with this cover; - the ring comprises a tubular part, one end of which is connected to the collar, this tubular part being mounted in the orifice and having a length greater than that of the orifice; - the nut comprises an external cylindrical surface which is connected to the annular face of the nut, and which comprises a series of recesses regularly distributed around the nut and configured to cooperate with a screwing / unscrewing tool of the nut;

[0027] — the loop or hook is located at a longitudinal end of the threaded rod;

[0028] — the ring is immobilized in rotation in its mounting hole, for example thanks to tight assembly or by complementarity of shapes.

[0029] The invention also relates to a nacelle for a propulsion unit, comprising first and second cowls, as well as a lock as described above, the first part of the lock being fixed to the first cowl, and the second part of the lock being intended to be fixed to the second cowl.

[0030] The invention also relates to a propulsion assembly, in particular for an aircraft, comprising at least one nacelle as described above. Brief description of the figures

[0031] The present invention will be better understood and other details, features and advantages of the present invention will become more apparent upon reading the following description of a non-limiting example which follows, with reference to the attached drawings in which: [Fig.l] [Fig.l] is a schematic overview in axial section of a propulsion unit nacelle; [Fig.2] [Fig.2] is a schematic perspective view of a nacelle lock; [Fig.3] [Fig.3] is a schematic sectional view of a lock in a locked position; [Fig.4] [Fig.4] is a schematic sectional view of the lock of [Fig.2] in an unlocked position; [Fig.5] [Fig.5] is a schematic perspective and sectional view of a lock according to a first embodiment of the invention, in a locked position;

[0032] [Fig.6] [Fig.6] is another schematic sectional view of the lock of [Fig.5], in the locked position; [Fig.7] [Fig.7] is a partial schematic perspective view of a lock according to one embodiment of the invention;

[0033] [Fig.8a-8c] Figures 8a to 8c are partial schematic perspective views or in section of the lock of [Fig.7];

[0034] [Fig.9a-9c] Figures 9a to 9c are views similar to those of Figures 8a to 8c and illustrate a lock according to an alternative embodiment of the invention;

[0035] [Fig. 10] [Fig. 10] is a very schematic view illustrating a variant of the rea lization of projections and associated holes. Detailed description of the invention

[0036] [Fig.l] shows a nacelle 10 containing a turbomachine supported by a pylon 4 fixed under the wing of an aircraft. The nacelle comprises a front section 6 comprising a profiled air inlet, a central section 2 surrounding a cold air blower 14, and a rear section 8 comprising a thrust reverser, for example with grilles or doors. The nacelle forms an external profiling of the annular vein 12 guiding the flow of cold air, and an external aerodynamic fairing.

[0037] The nacelle has a longitudinal axis A and has an annular shape around this axis. The central section 2 of the nacelle comprises two external covering hoods, arranged symmetrically with respect to a vertical axial plane P (which is for example the section plane of [Fig.l]). These hoods can open laterally by pivoting around a hinge comprising a longitudinal axis arranged in the upper part and parallel to the longitudinal axis A of the nacelle. The rear section comprises two rear lateral parts, which close on each other along the same plane P of axial symmetry.

[0038] The invention applies to any nacelle of a turbomachine comprising two cowls or two rear side parts which can open and close on each other, and in particular to the nacelle illustrated in [Fig.l]. In particular, these two cowls can be fan cowls or reverser cowls which slide backwards during a thrust reversal phase.

[0039] [Fig. 2] is a bottom view of the nacelle 10 showing at the top the two front cowls 20, 22 and at the bottom the two rear parts 24, 26, these cowls and these closed rear parts connecting along the plane of symmetry P. The two rear parts 24, 26 are clamped to each other in a tangential direction by several locks, including a lock comprising an actuating handle 28, maneuvering in a transverse plane. In the particular case illustrated in the drawing, the lock is mounted at the module limit, at the rear of fan cowls and in front of a thrust reverser. When this lock is locked and the front cowls 20, 22 are closed, the handle 28 is arranged in a fitted manner in a transverse external cutout extending over these two cowls, at the limit of the rear parts 24, 26.The free end of the handle 28 which tilts in the maneuver, shown on the right of the figure, has a recess which shifts it slightly towards the axis of the nacelle, to come below the right front cover 20. Alternatively, the lock could be located in the middle of a cover cutout of the same module.

[0040] Figures 3 and 4 show the handle 28 fixed by pivots to a first half-structure 27, acting by a rocker 34 on a locking lever comprising a main hook 30 coming to take a loop 33 located at the end of a rod 32 fixed to a second half-structure 25. Once the handle 28 is completely closed, a safety hook 36 pivotally fixed on the handle 28, automatically locks by the action of a spring on the main hook 30 or another element of the lock. To open the handle 28, it is necessary to press on a pusher 38 of the safety hook 36 located in the outer plane of the handle 28, in order to press on it to release this hook and free this handle which can then tilt.

[0041] The outer surface of the handle 28 fitted into the cutout of the covers 20, 22, comes substantially level with the surface of these covers in order to obtain aerodynamic continuity of the outer surface of the nacelle.

[0042] The front cover 20 being closed, it is then no longer possible to open the handle 28, nor to close it if it is open. Furthermore, the handle 28 being held open by a spring, and the main hook 30 being tilted downwards, protruding radially outwards from the half-structures 25, 27 supporting it, the cutting of the covers 20, 22 makes it possible in all cases, when they are closed or dropped, not to hit an element of the lock, in particular the handle and the hook.

[0043] The lock as illustrated in Figures 3 and 4, and in particular the mechanism between the handle 28 and the hook 30, is of the three-point type, well known to those skilled in the art. job.

[0044] We now refer to Figures 5 to 8 which illustrate a first embodiment of a lock 50 according to the invention.

[0045] The lock 50 essentially comprises two parts 52, 54 which are intended to be fixed respectively to two covers, such as the covers 20, 22, or to two half-structures 25, 27, as in the aforementioned example.

[0046] The first part 52 of the lock 50 is that comprising the hook 30 and the actuating handle 28.

[0047] The hook 30 is movable from an unlocking position, comparable to that of [Fig. 4], to a locking position illustrated in Figures 5 and 6.

[0048] The actuating handle 28 is connected to the hook 30, for example by a three-point mechanism, and is movable from a closed position illustrated in FIGS. 5 to 8, to an open position comparable to that of [Fig. 4]. This movement can be achieved by pivoting or tilting.

[0049] The movement of the actuating handle 28 from its closed position to its open position causes the movement of the hook 30 from its locked position to its unlocked position, and vice versa, thanks to the aforementioned mechanism.

[0050] The second part 54 of the lock 50 comprises a stirrup 56 and a support 58 comprising a tab 60 for fixing the stirrup 56 to the structure.

[0051] The stirrup 56 comprises a threaded rod 62 and the loop 33 which is located at a longitudinal end of this threaded rod 62 and which is configured to cooperate with the hook 30 of the first part 52.

[0052] The threaded rod 62 passes through an orifice 64 of the lug 60 of the support 58 and an adjustment nut 66 is screwed onto the threaded rod 62. Screwing / unscrewing this nut 66 onto the threaded rod 62 makes it possible to adjust the position of the loop 33 of the stirrup 56 with respect to the lug 60 of the support 58 (according to the double arrow F1 of [Fig.6]).

[0053] The hook 30 is able to engage on the loop 33 of the stirrup 56 when the hook 30 is moved from its unlocking position ([Fig.4]) to its locking position (figures 5-6), and to disengage from the loop 33 of the stirrup 56 when the hook 30 is moved from its locking position (figures 5-6) to its unlocking position ([Fig.4]). More precisely, the movement of the actuating handle 28 from its closed position to its open position causes the movement of the hook 30 from its locked position to its unlocked position and the disengagement of the hook 30 from the loop 33, and conversely, the movement of the actuating handle 28 from its open position to its closed position causes the movement of the hook 30 from its unlocked position to its locked position and the engagement of the hook 30 in the loop 33.

[0054] The lock 50 may also include a safety hook 36 as seen in [Fig.5] and as described above.

[0055] The threaded rod 62 of the stirrup 56 is mounted axially sliding in the orifice 64 of the lug 60, along an axis of elongation A of the threaded rod 62.

[0056] The second part 54 may here comprise a guide ring 68 which is inserted into the orifice 64 of the lug 60 and which is crossed by the threaded rod 62 of the stirrup 56. This ring 68 comprises an external annular collar 68a which is intended to be interposed between the lug 60 and the nut 66.

[0057] The ring 68 is preferably immobilized in rotation in the orifice 64. This immobilization can be obtained by a tight mounting of the ring 68 in the orifice, for example by shrinking. Alternatively, the immobilization could be obtained by complementarity of shapes, the ring comprising for example a flat cooperating with a complementary element of the tab 60.

[0058] The second part 54 may further comprise an elastic element 69 which axially stresses the loop 33 on the side opposite the nut 66. This elastic element 69 may be a helical spring which is mounted around the threaded rod 62 and interposed axially between the loop 56 and the lug 60 or the ring 68. The elastic element 69 or the spring bears for example axially respectively on the loop 33 and on the lug 60 or on the end of the ring 68 opposite its collar 68a.

[0059] The stirrup 56 is advantageously axially movable in the orifice 64 of the lug 60, or in the ring 68, from a retracted position in which the nut 66 is axially spaced from the lug 60 and the ring 68, and an advanced position in which the nut 66 is axially pressed against the lug 60 or the ring 68. The advanced position of the nut 66 is shown in Figures 5 and 6, and its retracted position is shown diagrammatically in dotted lines in [Fig.6].

[0060] Figures 7 and 8a to 8c illustrate a first embodiment of the invention in which the lock 50 differs from that described above in that the collar 68a of the ring 68 comprises an annular face 68al which is intended to bear on an annular face 66a of the nut 66, the face 68al comprising projections 70 capable of being engaged in holes 72 of the face 66a to allow rotational immobilization of the nut 66 with respect to the ring 68 as long as these elements are bearing on each other.

[0061] The number of projections 70 is equal to the number of holes 72, which makes it possible to guarantee the immobilization in rotation of the nut 66 and the ring 68 as long as they are supported on each other.

[0062] This number is preferably between 8 and 20.

[0063] In the example shown, each of the projections 70 has a spherical cap shape.

[0064] The holes 72 are preferably blind holes of a shape complementary to the projections 70. Preferably, the engagement of the projections 70 in the holes 72 is carried out with clearance to ensure that all of the projections interface correctly with the holes. This clearance can be determined according to the manufacturing tolerances of the parts and in particular the machining of the projections and the holes.

[0065] The orifice 64 for mounting the ring 68 may be formed in a tab 60 of a support integral with the corresponding cover or formed in a single piece with this cover.

[0066] In the example shown, the ring 68 comprises a tubular part 68b, one end of which is connected to the collar 68a, this tubular part 68b being mounted in the orifice 64 and having a length greater than that of the orifice 64.

[0067] The nut 66 may comprise an external cylindrical surface 66b which is connected to the annular face 66a of the nut 66, and which comprises a series of recesses 74 regularly distributed around the nut 66 and configured to cooperate with a tool for screwing / unscrewing the nut. These recesses 74 are for example blind holes.

[0068] Figures 9a and 9c illustrate an alternative embodiment of the invention which differs from the previous embodiment essentially in that it is the face 68al of the collar 68a of the ring 68 which comprises the holes 72, and it is the face 66a of the nut which comprises the projections 70, the projections 70 being able to be engaged in the holes 72 to allow rotational immobilization of the nut 66 with respect to the ring 68 as long as these elements are supported on each other.

[0069] The number of projections 70 is always equal to the number of holes 72. This number is preferably between 8 and 20.

[0070] In Figures 7 to 9c, the aforementioned elastic element 69 makes it possible to maintain constant axial support at rest between the faces 66a, 68al and therefore makes it possible to guarantee the immobilization in rotation of the nut 66 and the ring 68. When an operator screws or unscrews the nut 66, he can feel the passage from one notch or step to another, each step or notch being marked by the engagement of the projections with the holes 70. It is understood that there are as many notches or steps around the axis of the nut 66 as there are projections or holes.

[0071] In the embodiment described above and illustrated in Figures 7 to 9c, the projections 70 each have a boss or boss shape. Alternatively, the projections could have a different shape, chosen for example from teeth, crenellations, chevrons, fingers, etc. The holes 72 would each have a shape complementary to this particular shape. [Fig. 10] illustrates for example a variant in which the projections 70 and the associated holes 72 are crenellated.

[0072] In a variant of the invention not shown, it is not the loop 33 which is connected to the threaded rod 62 but it is the hook 30. The hook 30 can be connected to a longitudinal end of the threaded rod 62 and an assembly with adjustment nut 66 and ring 68, similar to that described above, can be adopted.

[0073] The lock according to the invention has numerous advantages, including: - reduction in the number of parts to ensure immobilization of the nut, - the reliability and simplicity of this immobilization, - the deception mentioned above, - there is no risk of forgetting to immobilize the nut because this immobilization is automatic, - etc.

Claims

Claims

1. Lock (50) for a propulsion unit nacelle, in particular of an aircraft, comprising first and second covers (20, 22), the lock (50) comprising: - a first part (52) intended to be fixed to the first cover (20) and comprising a hook (30) and a handle (28) for actuating the hook (30), the hook (30) being movable from an unlocking position to a locking position, the actuating handle (28) being connected to the hook (30) and being movable from a closing position to an opening position, the movement of the actuating handle (28) from its closing position to its opening position causing the movement of the hook (30) from its locking position to its unlocking position, and vice versa, and - a second part (54) intended to be fixed to the second cover (22) and comprising a stirrup (56) comprising a loop (33) which is configured to cooperate with said hook (30), the first or second part (52, 54) comprising a threaded rod (62) which is connected to said hook (30) or to said loop (33), this threaded rod (62) receiving an adjustment nut (66) the screwing / unscrewing of which makes it possible to adjust the position of the loop (33) of the stirrup (56) with respect to the hook (30), or conversely, the first or second part (52, 54) comprising an orifice (64) in which is mounted a ring (68) crossed by the threaded rod (62), this ring (68) comprising an external annular collar (68a) of which an annular face (68al) is capable of bearing on an annular face (66a) of the adjustment nut (66), the hook (30) being capable of engaging on the loop (33) of the stirrup (56) when the hook (30) is moved from its unlocking position to its locking position, and to disengage from the loop (33) of the stirrup (56) when the hook (30) is moved from its locking position to its unlocking position, characterized in that one of the faces chosen from the annular face (68al) of the collar (68a) and the annular face (66a) of the nut (66) comprises a number of projections (70), and the other of these faces comprises the same number of holes (72), said projections (70) all being intended to be engaged in said holes (72) when the faces are bearing against each other, so as to secure the nut (66) in rotation and the ring (68).

2. The lock (50) of claim 1, wherein said number of projections (70) is between 8 and 20.

3. A lock (50) according to claim 1 or 2, wherein each of the projections (70) has a spherical cap shape.

4. Lock (50) according to one of the preceding claims, in which the holes (72) are blind holes of complementary shape to the projections.

5. Lock (50) according to one of the preceding claims, in which said orifice (64) for mounting the ring (68) is formed in a tab (60) of a support integral with the corresponding cover or formed in one piece with this cover.

6. Lock (50) according to one of the preceding claims, in which the ring (68) comprises a tubular part (68b) one end of which is connected to the collar (68a), this tubular part (68b) being mounted in the orifice (64) and having a length greater than that of the orifice.

7. A lock (50) according to any preceding claim, wherein the projections (70) are selected from bosses, teeth, crenellations, chevrons, and fingers.

8. Lock (50) according to one of the preceding claims, in which the nut (66) comprises an external cylindrical surface (66b) which is connected to the annular face (66a) of the nut, and which comprises a series of recesses (74) regularly distributed around the nut (66) and configured to cooperate with a tool for screwing / unscrewing the nut.

9. Nacelle (10) for a propulsion unit, in particular for an aircraft, comprising first and second cowls (20, 22), as well as a lock (50) according to any one of the preceding claims, the first part (52) of the lock (50) being fixed to the first cowl (20), and the second part (54) of the lock (50) being intended to be fixed to the second cowl (22).

10. Propulsion assembly, in particular for an aircraft, comprising at least one nacelle according to the preceding claim.

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