FR3045562A1 - FLIGHT CONTROL DEVICE - Google Patents

Abstract

The invention relates to a flight control device (1) for aircraft comprising: - a housing (2), - a handle (4) rotatably mounted relative to the housing (2) in at least one axis of rotation, - a protection assembly (5) comprising a first protective wall (53) fixedly mounted with respect to the housing (2), the first protective wall (53) having an outer surface of convex shape and having an opening through which extends the handle (4), and a second protective wall (54) fixedly mounted relative to the handle (4), the second protective wall (54) having an inner surface of concave shape arranged opposite and at a distance from the first surface so as to cover the opening (55) when the handle (4) is rotated relative to the housing (2).

Description

FIELD OF THE INVENTION The invention relates to a flight control device for an aircraft.

STATE OF THE ART

In aircraft, the flight control devices allow the pilot to control the orientation of the roll and pitch control surfaces.

Document FR 3,011,815 discloses an aircraft flight control device comprising a lever and a frame. The lever is connected to the frame by means of a mechanical link assembly allowing a rotation of the lever relative to the frame according to two axes of rotation X and Y perpendicular. The rotation of the lever relative to the frame allows to orient the control surfaces to control the roll and pitch movements of the aircraft. The mechanical link assembly also connects the lever to actuators to simulate a force feedback during rotation of the lever.

In order to prevent the penetration of foreign bodies, liquids, or other pollutants (such as dust, for example) into the mechanical linkage assembly, the device includes a bellows seal connecting the lever to the frame.

Such seals are generally formed of a flexible polymeric material, such as an elastomer for example.

A disadvantage of this type of material is that it has a service life shorter than the life of the flight control device. Therefore, the protective seal is a part that must be replaced during the life of the device.

In addition, in case of damage to the seal (for example if the seal is pierced), the mechanical connection assembly can be polluted by the penetration of foreign bodies, liquid, or other pollutants.

Furthermore, during the movement of the lever relative to the frame, the bellows of the protective seal rub against each other, which generates friction forces that disturb the servo control chain of the actuators.

In addition, the stiffness of the bellows seal varies depending on the temperature.

The taking into account of these friction forces, as well as variations of stiffness of the seal as a function of temperature, in the servo control chain of the actuators is complex. In addition, the friction forces generated by the bellows do not follow a law of linear evolution as a function of the position of the lever.

These friction forces are all the more troublesome as the forces generated by the actuators are low. Indeed, in this case, it is not possible to create a force feedback with good accuracy, unless designing complex control loops.

Finally, the bellows seals are not intended to be used in the case of control devices in which the lever is rotatable along three axes, the bellows not allowing a rotation of the lever in three degrees of freedom.

SUMMARY OF THE INVENTION

An object of the invention is to provide a flight control device that is protected against the penetration of pollutants throughout the life of the device without requiring parts replacement.

Another object of the invention is to provide a control device for improving the accuracy of the generated force feedback.

This object is achieved in the context of the present invention by means of an aircraft flight control device comprising: a housing, a lever, rotatably mounted relative to the housing according to at least one axis of rotation, a protection assembly, comprising a first protective wall mounted fixed relative to the housing, the first protective wall having an outer surface of convex shape and having an opening through which the handle extends, and a second protective wall mounted fixed relative to the handle, the second protective wall having an inner surface of concave shape arranged opposite and away from the first surface so as to cover the opening when the handle is rotated relative to the housing.

As the second wall covers the opening of the first wall, the second wall prevents the penetration of pollutants inside the housing through the opening.

In addition, as the second wall is arranged opposite and at a distance from the first wall, the walls do not rub against each other during movement of the lever relative to the housing and therefore do not generate friction.

The device may furthermore have the following characteristics: the external surface has a substantially spherical shape, the inner surface has a substantially spherical shape, the protection assembly further comprises a seal interposed between the first wall and the second wall. - the seal is attached to the second protective wall, - the seal is a brush seal, - the protection assembly comprises at least one flange extending radially from one of the first wall and the second wall towards the other of the first wall and the second wall, defining a tortuous path between the walls, - the rim surrounds the opening, - the lever is rotatably mounted relative to the housing along two axes or three axes of rotation the device comprises a mechanical connection unit housed inside the casing for linking the lever to the casing, allowing rotation of the lever with respect to the casing; the axes of rotation, the mechanical link assembly comprising at least two coaxial transmission shafts, each transmission shaft being connected to a respective motor to generate a force return on the handle according to each of the axes of rotation.

PRESENTATION OF THE DRAWINGS Other characteristics and advantages will become apparent from the description which follows, which is purely illustrative and nonlimiting, and should be read with reference to the appended figures, among which: FIG. 1 schematically represents a control device FIG. 2 diagrammatically shows, in an exploded view, the device of FIG. 1; FIG. 3 is a diagrammatic view, in sectional view, of the device of FIG. FIGS. 1 to 4 show three positions of the lever with respect to the housing (neutral position, first end position and second end position); FIGS. 7a to 7d show diagrammatically various embodiments of the protection package.

DETAILED DESCRIPTION OF AN EMBODIMENT

With reference to FIGS. 1 to 3, the flight control device 1 comprises a housing 2, a mechanical connection assembly 3, a handle 4 and a protection assembly 5.

The casing 2 is intended for example to be integrated in an armrest of a flight seat.

The handle 4 protrudes from the housing 2. The handle 4 has a gripping portion 41 adapted to be gripped by the hand of the driver and a connecting piece 42 for connecting the handle 4 to the mechanical assembly of link 3. The lever 4 is rotatably mounted relative to the casing 2 along three axes of rotation, namely: a roll axis x, a pitch axis y and a yaw axis z. The mechanical link assembly 3 is housed inside the casing 2. The mechanical linkage assembly 3 makes it possible, on the one hand, to link the lever 4 to the casing 2 by allowing the lever 4 to be rotated relative to the casing. 2 along the three axes of rotation, and secondly, to link the lever 4 to actuators to generate a force feedback on the handle 4 along the three axes of rotation.

The mechanical connection assembly 3 may be a mechanical connection assembly according to that described in document FR 3,011,815 in relation to FIGS. 12 to 21 of this document. Such a mechanical linkage assembly comprises two coaxial transmission shafts, each transmission shaft being connected to a respective motor. The motors make it possible to carry out a force return on the handle 4 when the pilot manipulates the joystick. The protection assembly 5 comprises a first cover 51 fixedly mounted on the housing 2 and a second cover 52 fixedly mounted on the handle 4.

The first cover 51 comprises a first wall 53 having a first opening 55 through which extends the connecting piece 42 of the handle 4. The first opening 55 is dimensioned to allow a movement of the handle 4 along the axis of roll x and along the pitch axis y.

In addition, the connecting piece 42 has a recess 43, in the form of a groove, adapted to receive the edges of the wall 53 defining the first opening 55 when the handle 4 is rotated about the roll axis x and around the pitch axis y. This feature makes it possible to increase the movement of the handle 4, without increasing the dimensions of the first opening 55.

The first wall 53 has an outer surface 531 having a generally convex spherical shape. The center O of the sphere is also the point of intersection of the roll axis x and the pitch axis y.

The first cover 51 can be fixed on the housing 2 by means of screws 21 or any other suitable fastening means.

The second cover 52 includes a second wall 54 extending around the handle 4. The second wall 54 has an inner surface 541 having a generally concave spherical shape. The center O of the sphere is also the point of intersection of the roll axis x and the pitch axis y. In this way, the position of the center O of the sphere does not change when the handle 4 is displaced in rotation relative to the housing 2.

The second wall 54 extends opposite and at a distance from the first wall 53. The first wall 53 and the second wall 54 define between them an interstice ei (or clearance). In this way, the second wall 54 is not in contact with the first wall 53, which avoids generating friction during the movement of the lever 4 relative to the casing 2. The gap ei formed between the two walls 53 and 54 has a radial dimension of, for example, between 2 and 7 millimeters.

The second wall 54 further has a second opening 57 for the passage of electrical connections between the gripping portion 51 and the connecting portion 42.

Figures 4 to 6 show three positions of the handle 4 relative to the housing 2.

In Figure 4, the handle 4 is in the neutral position. In this position, no force is exerted by the pilot on the joystick.

In Figure 5, the handle 4 is rotated about the roll axis x, in a first direction, to a first extreme position, with a deflection angle a.

In Figure 6, the handle 4 is rotated about the roll axis x, in a second direction, opposite the first direction, to a second extreme position, with a deflection angle -a.

As illustrated in Figures 4 to 6, the second wall 54 covers the first opening 55, as well as a portion of the first wall 53, so that the first opening 55 is never discovered regardless of the position of the joystick 4 This prevents debris or liquid from entering the housing 2 through the first opening 55. The protection assembly 5 may also include a seal 56 arranged between the first wall 53 and the second wall 54. in order to prevent the penetration of debris or liquid into the gap formed between the two walls 53 and 54. The seal 56 is preferably a non-contact seal.

In the embodiment illustrated in Figures 4 to 6, the seal 56 a brush seal.

The brush seal 56 is fixed on the inner surface 541 of the second wall 54. The brush seal 56 is disposed on the second wall 54 so as to surround the first opening 55 regardless of the position of the handle 4 relative to the 2. More specifically, the brush seal 56 extends along the free edges of the second wall 54.

As illustrated more specifically in FIG. 4, the brush seal 56 comprises a sole 561 and fibers 562 protruding from the sole 561. The fibers 562 thus projecting from the inner surface 541 of the second wall 54. The free ends of the fibers 562 are applied against the outer surface 531 of the first wall 53. The advantage of the brush seal 56 is that it generates weak friction forces and which follow a law of linear evolution. These friction forces can therefore be easily taken into account in the enslavement chain of the actuators.

Figures 7a to 7d schematically show other possible embodiments of the protection assembly.

In the embodiment illustrated in FIG. 7a, the protection assembly 5 comprises a first flange 58 and a second flange 59, arranged head to tail. The flanges 58 and 59 surround the first opening 55. The first flange 58 extends radially from the second wall 54 and the second flange 59 extends radially from the first wall 53. The first flange 58 extends to the first wall 53 while the second flange extends to the second wall 54. However, the first flange 58 is not in contact with the outer surface 531 of the first wall 53. Similarly, the second flange 59 n is not in contact with the inner surface 541 of the second wall 54. There remains a small gap e2 (smaller than the gap e-ι) between the flanges 58, 59 and the walls 53, 54. Thus, the flanges 58, 59 generate no friction force when the handle 4 is rotated relative to the casing 2. The gap e2 formed between the first flange 58 and the first wall 53 has a radial dimension of between 0.5 and 1.5 millimeters , for example 1 millimeter e. Similarly, an identical gap e2 is formed between the second flange 59 and the second wall 54.

The first rim 58 and the second rim 59 define a tortuous path or baffle between the walls 53 and 54 which makes it difficult for pollutants to penetrate between these walls.

In the embodiment illustrated in FIG. 7b, the protection assembly 5 comprises two brush seals 56 and 57.

The first brush seal 56 is attached to the inner surface 541 of the second wall 54. The first brush seal 56 extends along the free edges of the second wall 54. The first brush seal 56 includes a sole 561 and fibers 562 protruding from the sole 561. The fibers 562 thus projecting from the inner surface 541 of the second wall 54. The free ends of the fibers 562 are applied against the outer surface 531 of the first wall 53.

The second brush seal 57 is fixed on the outer surface 531 of the first wall 53. The second brush seal 57 extends along the free edges of the first wall 53, these free edges delimiting the opening 55. The second The brush seal 57 is identical to the first brush seal 56. It comprises a sole 571 and fibers 572 protruding from the sole 571. The fibers 572 thus projecting from the outer surface 541 of the first wall 53. The free ends of the fibers 572 are applied against the inner surface 541 of the second wall 54.

In the embodiment illustrated in FIG. 7c, the protection assembly 5 comprises both a brush seal 56 and a flange 59.

The brush seal 56 is identical to the first brush seal 56 of Figure 7b and the flange 59 is identical to the second flange of Figure 7a.

In the embodiment illustrated in FIG. 7d, the protection assembly 5 comprises a flange 58 and a brush seal 57.

The brush seal 57 is identical to the second brush seal 57 of Figure 7b and the flange 59 is identical to the second flange 59 of Figure 7a.

Claims (10)

A flight control device (1) for an aircraft comprising: - a housing (2), - a handle (4) rotatably mounted relative to the housing (2) in at least one axis of rotation, - a protection assembly (5) comprising a first protective wall (53) fixedly mounted with respect to the housing (2), the first protective wall (53) having an outer surface (531) of convex shape and having an opening (55) through which extends the handle (4), and a second protective wall (54) fixedly mounted relative to the handle (4), the second protective wall (54) having an inner surface (541) of concave shape arranged opposite and away from the first surface (531) so as to cover the opening (55) when the handle (4) is rotated relative to the housing (2). 2. Device according to claim 1, wherein the outer surface (531) has a substantially spherical shape. 3. Device according to one of claims 1 and 2, wherein the inner surface (541) has a substantially spherical shape. 4. Device according to one of claims 1 to 3, wherein the protective assembly (5) further comprises a seal (56) interposed between the first wall (53) and the second wall (54). 5. Device according to claim 4, wherein the seal (56) is fixed on the second protective wall (54). 6. Device according to one of claims 4 and 5, wherein the seal (56) is a brush seal. 7. Device according to one of claims 1 to 6, wherein the protective assembly (5) comprises at least one flange (58, 59) extending radially from one of the first wall and the second wall (53, 54) towards the other of the first wall and the second wall (53, 54), defining a tortuous path between the walls (53, 54). 8. Device according to claim 7, wherein the flange (58, 59) surrounds the opening (55). 9. Device according to one of claims 1 to 8, wherein the handle (4) is rotatably mounted relative to the housing (2) along two axes (x, y) or three axes of rotation (x, y, z) . 10. Device according to claim 9, comprising a mechanical connection assembly (3) housed inside the housing (2) for connecting the handle (4) to the housing (2) by allowing a rotation of the handle (4) by relative to the housing (2) along the axes of rotation, the mechanical link assembly (3) comprising at least two coaxial transmission shafts, each transmission shaft being connected to a respective motor to generate a force feedback on the controller (4) according to each of the axes of rotation.