POSITION SENSOR FOR A THRUST REVERSING VALVE OF AN AIRCRAFT GONDOLA

Description

[0001] The present invention relates to a position sensor for a thrust reverser door of an aircraft nacelle.

[0002] An aircraft is propelled by one or more propulsion units, each comprising a turbojet engine housed in a tubular nacelle. Each propulsion unit is attached to the aircraft by a mast, generally located under or on a wing or at the level of the aircraft's fuselage.

[0003] A nacelle generally has a tubular structure comprising an air inlet upstream of the turbojet, a middle section intended to surround a turbojet fan, a downstream section which may house thrust reversing means and is intended to surround the turbojet combustion chamber, and is generally terminated by an ejection nozzle whose outlet is located downstream of the turbojet.

[0004] Thrust reversing means are used during aircraft landing to improve braking capacity by redirecting at least a portion of the thrust generated by the turbojet engine forward. These means include a thrust reverser comprising movable thrust reversing elements, typically two movable thrust reversing elements, mounted on the nacelle to move between a closed position (direct jet) in which the thrust reverser is inactive, and an open position (reverse jet) in which the thrust reverser is active, i.e., it redirects at least a portion of the gas flow generated by the turbojet engine in the opposite direction to the flow guided by the nacelle. The downstream section of a nacelle therefore comprises a fixed structure and a movable structure.

[0005] In one type of thrust reversal, the reversing moving elements are gates. In another type of thrust reversal, the reversing moving elements are grids.

[0006] This patent application relates to gated thrust inverters.

[0007] The actuation of thrust reverser doors is generally achieved by means of actuators mounted on the nacelle and connected on one side to a motor, and on the other side to the doors to maneuver them in a direction of retraction or deployment over a stroke of the actuators between the closed position and the open position of the doors.

[0008] It is also known to include a door locking system in the closed position to eliminate any risk of the doors opening unintentionally. Typically, these locking systems consist of hook-shaped latches controlled by a control unit connected to door position sensors. These sensors provide the control unit with the information necessary for the proper functioning of the locking system regarding the door positions.

[0009] One type of door position sensor, called a proximity sensor, includes sensing elements which are: a detector attached to the fixed structure of the gondola, and a target attached to the door.

[0010] The detector can be a magnetic detector emitting a magnetic field, in which case the target is adapted to change the state of this magnetic field when it is substantially opposite the detector. Alternatively, the detector is an optical detector emitting a light beam, for example, via an array of diodes or lasers, in which case the target includes a means of reflecting the light beam, such as a mirror, adapted to reflect the light beam emitted by the detector when the target is substantially opposite the detector. In another variant, the detector is an electromagnetic detector comprising a contact lever, which can be actuated by the target when the target is substantially opposite the detector.

[0011] The detection range of these known sensors is very limited. They can typically detect a target located at a maximum distance of 5 mm. Therefore, the tolerances between the door and the fixed structure, and more specifically the tolerance between the detector on the fixed structure and the target on the door, must be very small, on the order of 5 mm. To ensure the proper functioning of these position sensors, the detection elements (detector and target) must be shimmed with shims, and door centering devices (called spigots) must be installed on the fixed structure. These centering devices must have small clearances (on the order of 1 mm) to limit the relative movement of the door, which generates significant stresses at the interfaces, particularly at the spigots.

[0012] US 5,826,823 A discloses an aircraft turbojet nacelle. The nacelle includes a fixed structure and a thrust reverser. The thrust reverser includes a fixed structure and rotating movable doors. The nacelle includes at least one position sensor for one of the doors. The sensor includes a target to be detected; a detector configured to detect the target when it enters its detection range; and a guide (in the form of the hinge of a cylinder on which the target is mounted) configured to guide the target to position it within the detector's detection range. The nacelle includes a door locking system for the closed position, and the detector and guide are mounted on the fixed structure of the thrust reverser.

[0013] Furthermore, these constraints necessitate numerous adjustment operations when changing the door.

[0014] To overcome these drawbacks, electromechanical sensors are known to use a contact lever, which can be activated by the target when it moves the lever. These sensors are called stow switches.

[0015] However, these types of sensors are heavy. Furthermore, their moving mechanism is susceptible to wear.

[0016] The present invention aims to solve the drawbacks encountered with prior art door position sensors, by proposing a lightweight sensor, which simplifies the design of the inverter by reducing the constraints to be respected.

[0017] The present invention relates to this purpose to a nacelle for an aircraft turbojet engine according to claim 1, which includes, among other things, a position sensor for a thrust reverser door of the nacelle comprising: A target intended to be detected, a detector with a detection range and a detection head configured to detect the target when it enters its detection range, and a target guide configured to guide the target into position within the detector's detection range. In which the detector is fixed relative to the target guide.

[0018] Thus, the target is able to fall within the sensor's detection range without requiring shims, maintenance, or highly precise machining of the doors and fixed structure. The position sensor detects the door in the closed position.

[0019] The nacelle sensor according to the invention makes it possible to adjust the dimensional dispersions and those due to the operation of a thrust reverser, by guiding the target in the detection range of the detector, and by giving it a deflection in this detection range.

[0020] In addition, such a position sensor allows for gains in mass and manufacturing cost, and reduces the risk of detection errors.

[0021] Furthermore, the guide helps protect the target. It acts as a protective fairing.

[0022] The guide is configured to receive the target and position it within the detector's detection range.

[0023] According to other features of the invention, the gondola of the invention includes one or more of the following optional features.

[0024] According to one feature, the detector is mounted on the target guide.

[0025] According to one characteristic, the target is intended to be positioned on the door whose position is to be detected, and the detector and the target guide are intended to be positioned on the fixed structure of the thrust reverser.

[0026] According to this feature, the guide includes an opening into which the detector's sensing head is inserted so as to allow detection of the target inserted into the guide.

[0027] According to one characteristic, the target is configured to be located at a distance between 0 and 5 mm, and preferably on the order of 5 mm, from the detection head of the detector, when the target is inserted into the guide.

[0028] The guide allows the target to be positioned at a specific distance. The guide is configured to position the target at a predetermined distance from the detection head.

[0029] According to one characteristic, the position sensor is designed to send a signal to an external device when the target is within the detector's detection range.

[0030] According to one characteristic, the position sensor is a magnetic sensor.

[0031] According to this characteristic, the target is adapted to change the state of this magnetic field when it is within the detection range of the detector.

[0032] According to this characteristic, the target comprises at least one part of magnetic metallic material such as magnetic stainless steel or martensitic stainless steel and more particularly 15-5 PH, said part being configured to be within the detection range of the detector when the target is inserted into the guide, and the guide is of non-magnetic material, such as an organic material or polytetrafluoroethylene (PTFE).

[0033] According to one characteristic, the position sensor is an optical sensor.

[0034] According to this characteristic, the position sensor emits a light flux, for example via an array of diodes or lasers, and the target includes a means of reflecting the light flux, such as a mirror, adapted to reflect the light flux emitted by the detector when the target is within the detector's detection range.

[0035] According to one characteristic, the position sensor is an electromechanical sensor.

[0036] According to this feature, the position sensor includes a contact lever, which can be actuated by the target when the target is within the detector's detection range.

[0037] According to one characteristic, the guide is made of non-magnetic material, such as an organic material or polytetrafluoroethylene (PTFE).

[0038] According to one characteristic, the target is in the shape of a flexible blade.

[0039] The flexibility of the blade allows it to be inserted into the guide without requiring any effort. Thus, the position sensor according to the invention is simple and passive, and allows the target to be positioned within the detector's detection range.

[0040] According to one characteristic, the target has a thickness of approximately 2 mm.

[0041] This thickness allows it to have the flexibility necessary for its insertion into the guide.

[0042] According to one characteristic, the target has a variable thickness, the thickness being on the order of 2 mm at the level of the detector's detection range when the target is inserted into the guide.

[0043] According to one characteristic, the target includes an elastic portion allowing it to have the flexibility necessary for its insertion into the guide.

[0044] According to one feature, the guide has a groove into which the blade is suitable to be inserted.

[0045] The groove is positioned at a known distance from the detection head, in order to position the target within the detector's detection range.

[0046] According to one characteristic, the groove has rounded leading edges to guide the insertion of the blade.

[0047] One characteristic of this design is that the groove walls are made of a very low-adhesion material to limit friction with the blade and thus reduce wear on the blade or guide. Examples of such materials include polytetrafluoroethylene (PTFE), polyamide (PA66), and polyetheretherketone (PEEK tribo).

[0048] According to one characteristic, the groove is substantially conical, with the largest dimension being located at the target insertion end.

[0049] The blade length is limited so that it falls outside the detector's field of view when the door is not in the closed position. This allows the position sensor to detect the failure of a door retention element in the closed position, such as a locking mechanism.

[0050] According to the invention, the gondola includes a door locking system in the closed position comprising a door hook disposed on the door, intended to cooperate with a fixed hook disposed on the fixed structure of the thrust reverser, and the target is fixed on the door hook.

[0051] Thus, the target is positioned as close as possible to the hook, which improves the sensitivity of door closure detection and the sensitivity of hook breakage detection.

[0052] Other features and advantages of the present invention will become apparent from the following description and from an examination of the accompanying figures, in which: [ Fig. 1 ] There figure 1 This is a schematic perspective view of a thrust reverser on an aircraft turbojet nacelle in the closed position. Fig. 2 ] There figure 2 is a schematic perspective view of the thrust reverser of the figure 1 in the open position, allowing visualization of a portion of the sensor according to the invention. Fig. 3 ] There figure 3 is a schematic perspective view of an area of ​​the figure 2 . [ Fig. 4 ] There figure 4 is a schematic perspective view of a position sensor for a thrust reverser gate of the figure 1 The position sensor includes a target and a guide, the guide being partially represented to facilitate visualization of the target. Fig. 5 ] There figure 5 is a schematic cross-sectional view of the position sensor according to the invention. Fig. 6 ] There figure 6 is a schematic perspective view of the position sensor guide according to the invention.

[0053] In the description that follows and in the claims, identical, similar or analogous components will be designated by the same reference numerals.

[0054] There figure 1 illustrates a thrust reverser 10 of an aircraft turbojet nacelle.

[0055] The thrust reverser 10 has a longitudinal axis A corresponding to a longitudinal axis of the nacelle (not shown). It comprises a fixed structure 12 and two doors 14 in the closed position, in which they ensure aerodynamic continuity with the fixed structure 12 of the reverser and with the nacelle (not shown). The doors are rotatable about a transverse axis B, B' to the longitudinal axis A, between the closed position and an open position ( figure 2 ) in which they open a passage intended for the circulation of a diverted secondary airflow.

[0056] The thrust reverser 10 further includes a locking system 16 for each door 14 in the closed position and a position sensor 18 for each door 14, as will be seen with regard to the figure 2 .

[0057] There figure 2 illustrates the thrust reverser 10 of the figure 1 in the open position and allowing visualization of part of the locking system 16 and the position sensor 18 of a door 14.

[0058] There figure 3 illustrates in more detail the locking system 16 and the sensor 18 as shown in the figure 2 .

[0059] The locking system 16 includes a door hook 20 disposed on the door 14, intended to cooperate with a fixed hook 22 ( figure 4 ) arranged on the fixed structure 12 of the thrust reverser, but not visible on the figure 3 .

[0060] The position sensor 18 is a magnetic sensor. It comprises a detector 24 fixed to the fixed structure 12 of the inverter, a flexible blade 26 fixed to the door hook 20, and a guide 28 ( figure 4 ) for the blade 26, intended to guide the blade to position it within the detection range of the detector 24 when the door 14 is in the closed position.

[0061] Blade 26 is made of magnetic metallic material while guide 28 ( figure 4 ) is made of organic material.

[0062] THE figures 4 et 5 illustrate in more detail the position sensor 18, with the blade 26 in the inserted position in the guide 28.

[0063] The detector 24 includes a detection head 30 configured to detect the blade 26 when it enters its detection range, i.e. when it is positioned in the guide opposite the detection head 30 and at a distance of approximately 5 mm maximum from the detection head.

[0064] The position sensor is designed to send a signal to an external device (not shown) when the blade 26 is detected by the detector 24.

[0065] The blade 26 is a target of detector 24. It has a thickness "e" of 2 mm.

[0066] The guide 28 is shown partially to facilitate visualization of the detector 24. It is fixed to the fixed structure 12 of the inverter via the detector 24. It has a U-shape and has a groove 32 in each of its two arms 28A, 28B ( figure 6 ) parallels, into which blade 26 is intended to be inserted.

[0067] More specifically, detector 24 is mounted on guide 28, and guide 28 has an opening 34 ( figure 6 ) in which the detection head 30 is inserted so that the detection head 30 is opposite the groove 32 in order to be able to detect the blade 26 when it is positioned in the groove 32. The distance between the groove 32 and the detection head 30 is 3 mm.

[0068] The groove 32 has rounded leading edges 36 to guide the insertion of the blade into the groove 32. In addition, its internal walls 38 ( figure 6 ) are made of a very low adhesion material so as to limit friction with the blade 26.

[0069] There figure 6 represents the guide 28 of the sensor 18 according to the invention.

[0070] As indicated with regard to the figures 4 et 5 The guide 28 is a U-shaped block having grooves 32 in each of its parallel branches 28A, 28B. Each groove 32 has rounded leading edges 36 to guide the insertion of the blade into the grooves 32. In addition, the internal walls 38 of each groove 32 are made of a very low-adhesion material to limit friction with the blade.

[0071] The guide 28 also includes an opening 34 in its base 28C, in order to allow the insertion of the detection head 30 of the detector 24 ( figures 4 et 5 ).

Claims

1. A Nacelle for an aircraft turbojet engine, the nacelle having a longitudinal axis (A) and comprising a fixed structure and a thrust reverser (10), the thrust reverser comprising: - a fixed structure (12), and - at least one door (14), movable in rotation about an axis (B) transverse to the longitudinal axis of the nacelle, between a closed position in which it ensures aerodynamic continuity with the fixed structure of the nacelle during operation of the nacelle in direct jet and an open position in which it opens a passage intended for the circulation of a secondary air flow diverted during operation of the nacelle in reverse jet, said nacelle comprising at least one position sensor (18) of the door (14) of the thrust reverser (10), the sensor (18) including: - a target (26) intended to be detected; - a detector (24) having a detection range and including a detection head (30) configured to detect the target when it enters its detection range; and - a target guide (28) configured to guide the target in position within the detection range of the detector, the detector being fixed with respect to the target guide. the nacelle including a locking system (20, 22) of the door in the closed position comprising a door hook (20) disposed on the door, intended to cooperate with a fixed hook (22) disposed on the fixed structure of the thrust reverser, the target being fastened on the door hook, and the detector and the guide being mounted on the fixed structure of the thrust reverser.

2. The nacelle according to the preceding claim, wherein the detector is mounted on the target guide.

3. The nacelle according to the preceding claim, wherein the guide comprises an opening (34) into which the detection head of the detector is introduced so as to enable the detection of the target inserted into the guide.

4. The nacelle according to any one of the preceding claims, wherein the target is configured to be located at a distance between 0 and 5 mm, and preferably about 5 mm, from the detection head of the detector, when the target is inserted into the guide.

5. The nacelle according to any one of the preceding claims, the sensor being a magnetic sensor.

6. The nacelle according to the preceding claim, wherein the target includes at least one portion made of a magnetic metallic material such as magnetic stainless steel, or martensitic stainless steel and more particularly 15-5 PH, said portion being configured to be within the detection range of the detector when the target is inserted into the guide, and the guide is made of a non-magnetic material, such as an organic material or polytetrafluoroethylene (PTFE).

7. The nacelle according to any one of the preceding claims, wherein the target is a flexible blade.

8. The nacelle according to the preceding claim, wherein the target has a thickness (e) of about 2 mm.

9. The nacelle according to any one of claims 7 to 8, wherein the target includes an elastic portion allowing to give it the necessary flexibility to be inserted into the guide.

10. The nacelle according to any one of claims 7 to 9, wherein the guide has a groove (32) in which the blade is adapted to be inserted.

11. The nacelle according to the preceding claim, wherein the groove has rounded leading edges (36) allowing guiding the introduction of the blade.