THRUST REVERSER OF A TURBOFAN POD COMPRISING A SINGLE CONTROL FOR MOVABLE COWLINGS AND A VARIABLE NOZZLE

Abstract

A thrust reverser of a turbofan pod is provided that includes movable cowlings that retract relative to stationary front structure to reveal stationary or movable thrust reverser cascades, as well as a secondary variable nozzle section connected to the movable cowlings by guiding means enabling movement controlled by actuators engaged with the front structure to apply an axial thrust. The actuators are directly connected to the secondary nozzle, and in that the thrust reverser comprises latches connected to the movable cowlings, having two positions providing, alternately, latching onto the front structure or latching onto the control of the secondary nozzle.

Claims

1. A thrust reverser of a bypass turbojet engine nacelle comprising movable cowls which move backwards relative to a front fixed structure in order to uncover fixed or movable cascade vanes of thrust reverser, as well as a variable section secondary nozzle connected to the movable cowls by guide means allowing a controlled displacement by cylinders bearing on the fixed front structure in order to apply an axial thrust, wherein the cylinders are directly connected to the secondary nozzle and the thrust reverser includes locks linked to the movable cowls, the locks comprising two positions causing alternately a blocking on the front fixed structure or a blocking on a control of the secondary nozzle.

2. The thrust reverser according to claim 1, wherein the locks tilt in order to take the two positions.

3. The thrust reverser according to claim 2, wherein the locks are controlled from the front fixed structure.

4. The thrust reverser according to claim 3, wherein each lock includes a central pivot linked to the movable cowls, and axially on each side of each lock, an attachment device that is fixed, one to the front fixed structure, and the other to the control of the secondary nozzle.

5. The thrust reverser according to any of claim 1, wherein the locks are mounted on a pivot axis over about 90° in order to take their two positions.

6. The thrust reverser according to claim 5, wherein each lock defines an axis longitudinally disposed in the nacelle, guided in rotation by an element linked to the movable cowls, including at each end, an attachment device which can be alternately fixed, one to the front fixed structure and the other to the control of the secondary nozzle.

7. The thrust reverser according to claim 1 further comprising a movable part forming a safety which maintains blocking of the lock in each of the two positions.

8. The thrust reverser according to claim 7, wherein the movable part is a drawer guided by an element linked to the movable cowls, including a sliding movement for blocking the lock alternately in one of the two positions.

9. The thrust reverser according to claim 7, wherein the movable part is controlled by an actuator which moves the lock, a clearance being interposed between the actuator and the lock in order to allow a displacement of the movable part before moving the lock.

10. The thrust reverser according to claim 1, wherein the blocking of the locks include resilient means providing two blocking and unblocking stable positions.

11. The thrust reverser according claim 1, wherein the locks positioned on the movable cowl can be controlled from the front fixed structure and lock only the variable secondary nozzle relative the movable cowl.

12. A nacelle of a turbojet engine including a thrust reverser according to claim 1.

Description

DRAWINGS

[0028] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0029] FIGS. 1a, 1b and 1c are diagrams in axial section of a thrust reverser according to the present disclosure, presented successively in closed position with the retracted then deployed secondary nozzle, and in open position;

[0030] FIGS. 2a, 2b, 2c, 2d and 2e are views of a tilting lock for this thrust reverser, presented successively, with a blocking on the front structure, the nozzle being retracted then deployed, during the tilting of the blocking, and with a blocking on the cylinder, the cowls being closed then open; and

[0031] FIGS. 3a, 3b, 3c and 3d are views of a rotary lock for this thrust reverser, presented successively with a blocking on the front structure, the nozzle being retracted then deployed, during rotation, and with a blocking on the cylinder, the cowls being open.

[0032] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

[0033] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0034] FIG. 1 shows the rear portion of a jet engine nacelle, the rear axial direction being indicated by the arrow “AR”, comprising a front fixed structure 2, and movable cowls 4 fitted rearward of this structure.

[0035] Each cowl 4 is connected to the front structure 2 by longitudinal guide means, which allow a rearward sliding of these cowls in order to open the passage of the secondary flow radially outward, and to lower flaps 6 closing the outlet rearward, and returning the flow toward these passages comprising non represented thrust reverser cascade vanes.

[0036] A secondary nozzle 8 disposed at the rear of the nacelle, is connected to the cowls 4 by axial guide rails allowing a position retracted forward shown in FIG. 1a, and a position deployed rearward shown in FIG. 1b which improves the yields for the high rotation speeds of the turbojet engine.

[0037] Cylinders 10 axially disposed in the front structure 2 include a body fixed to this front structure, and a stem projecting rearward which is directly connected to the secondary nozzle 8 by an axial control rod 12 passing through the cowls 4 in their lengths.

[0038] A tilting lock 14 linked by a central pivot to the cowls 4, includes two blocking stable positions comprising alternately a front hook engaged on a front stud 18 fixed to the front structure 2, or a rear hook engaged on a rear stud 16 fixed to the control rod 12.

[0039] FIGS. 1a and 1b show the tilting lock 14 with its engaged front hook, which links the flaps 4 to the front structure 2. We can then control only the deployment of the nozzle 8, with the decrease of the cylinder 10 as shown in FIG. 1b.

[0040] FIG. 1c shows the tilting lock 14 with its rear hook engaged, which detaches the cowls 4 from the front structure 2 and fix them to the nozzle 8. The actuation of the cylinder 10 then causes the decrease of the assembly formed by the flaps 4 and the nozzle 8.

[0041] Thus, a control of two different movements which improves the force paths is made with a simple and compact actuator in order not to apply unnecessary constraint on the elements. In particular, a weighted connection between the cylinder 10 and the variable nozzle 8 is obtained in direct flow mode, which allows controlling the stroke and the stops of the movements of this nozzle, as well as a direct connection between the cylinder and the movable structure of the thrust reverser.

[0042] FIG. 2a shows a titling lock 14 which tilts about a pivot 24 perpendicular to the axis of the nacelle, fixed on an element 22 of the axially sliding structure with the movable flaps.

[0043] The lock 14 lying along the axis of the nacelle, includes symmetrically on either side of its pivot 24, a rear hook which can be engaged on a rear stud 16 as part of a fixation 20 connecting the end of the stem of the cylinder 10 to the control rod 12, and a front hook which can alternately be engaged on a front stud 18 fixed to a support 26 linked to the front structure 2.

[0044] The lock 14 includes at its front end a tip projecting from the hook, which is engaged between two parallel arms 30 each mounted on a pivot 32 fixed on the support 26, which are interconnected by a cross-member 38 mounted on joints in order to allow an inclination of these arms while maintaining their parallelism.

[0045] One of the arms 30 includes at its pivot 32 a substantially perpendicular elbow 34, terminating with a hinged connecting rod 36 which is connected to a drawer 44 guided both in the support 26 and in the element 22 linked to the movable flaps, in order to allow only a sliding movement along the axis of the nacelle without being able to laterally move away from the lock 14.

[0046] The arms 30 pivot under the effect of a non shown actuator performing a transverse movement according to the arrow “C”, in order to fix two stable end positions corresponding to the two blocking positions of the lock. This pivoting of the arms 30 causes a titling of the lock 14 comprising its engaged tip between these arms with a large clearance, as well as a sliding movement of the drawer 44 driven by the connecting rod 36, which includes a front pad 40 and rear pad 42 directed toward each of the hooks corresponding to this lock.

[0047] The operation of the lock is as follows.

[0048] FIG. 2a shows the front hook engaged on the stud 18 of the front structure 2, the axially guided drawer 44 having slid rearward so as to adjust its front pad 40 to the back of this hook, which prevents an accidental release from the hook which is thus locked on its stud.

[0049] With the lock 14 held in this position, FIG. 2b shows the cylinder 10 which deploys the secondary nozzle by a decrease of its stem driving the control rod 12 through the fixation 20. The structure of the movable flaps remains securely attached to the front structure 2, thanks to the drawer 44, which maintains the position of the lock 14.

[0050] The cylinder 10 as well as the secondary nozzle being retracted, FIG. 2c shows the arms 30 being pivoted under the effect of their actuator, starting by performing a forward sliding of the drawer 44 thereby unlocking the front hook of the lock 14 by the release of the front stud 40. The clearance between the front tip of the lock 14 and the two arms 30 allow starting to pivot these arms as well as the sliding movement of the drawer 44, before starting to tilt this lock.

[0051] FIG. 2d shows the end of the tilting of the lock 14, the rear pad 42 facing the rear hook, which locks the position comprising the detachment of the movable cowls from the front structure 2, and their reattachments in a safety manner to the rod 12 controlling the nozzle.

[0052] Then, as shown in FIG. 2e, the cylinder 10 can be actuated to decrease both the movable flaps and the secondary nozzle.

[0053] Advantageously, the lock 14 or its actuator include a non represented spring which, during a movement of the lock, is first compressed then expanded in order to provide two stable end positions corresponding to the two blocking positions of this lock.

[0054] FIG. 3a shows the lock 50 formed by an axis disposed longitudinally in the nacelle, guided in rotation by an element 22 of the structure linked to the movable cowls, including at each end a front 52 or rear 56 transverse bar which are disposed perpendicularly relative to each other.

[0055] The front bar 52 binds to the front structure 2 when it is vertical, by being engaged in upper and lower hooks 54 of this structure. Similarly, the rear bar 56 binds to the cylinder 10 when it is vertical by engaging in an upper hook 58 of the fixation 20, this bar being also engaged in a lower hook 58 mounted on a slide 60 fixed on the movable cowls 4.

[0056] Thus, a 90° rotation of the axis of the lock 50 is carried out by putting a vertical bar to engage it in the two hooks on its side, a blocking of the movable cowls 4 with alternately the front structure 2 or the secondary nozzle 8, the other horizontal bar can slide freely in front of the hooks corresponding to its side.

[0057] The operation of the lock is as follows.

[0058] FIG. 3a shows the axis of the lock 50 engaged on the hooks 52 of the front structure 2, and released from the hook 58 linked to the cylinder 10. Then, only the secondary nozzle 8 is operated as shown in FIG. 3b, by leaving the movable cowls 4 fixed to the front structure 2.

[0059] The cylinder 10 as well as the secondary nozzle being retracted, FIG. 3c shows the axis of the lock 50 pivoting under the effect of an actuator 62, thereby releasing the front bar 52 from its hooks 54 and engaging the rear bar 56 in the hook 58 linked to the cylinder 10.

[0060] Then, the movable cowls 4 are detached from the front structure 2, then, the assembly formed by these movable cowls and the secondary nozzle 8 is operated at the same time, as shown in FIG. 3d.