EP2295928B1 - Device for deploying and locking of a canard wing - Google Patents

Description

The technical field of the invention is that of devices for opening and locking duck wings for projectiles.

The guided projectiles are frequently equipped with duck wings which are housed in radial grooves of the projectile body. The duck wings are deployed after deployment driven by geared motors to control the projectile.

Licences US 6,880,780 B1 which forms a starting point for the preamble of claim 1, FR-2846079 , FR-2846080 , EP-1550837 and EP1772698 thus describe examples of duck wing deployment devices.

The deployment of the fin is generally provided by means of a spiral torsion spring surrounded around the axis of pivoting of the fin. This conventional solution, however, has disadvantages.

It happens indeed that the pivoting torque of the fin is insufficient or that it varies from one fin to the other leading to dissymmetries opening the ducks.

Furthermore, the locking means of the ducks in the deployed position most often include a pin which cooperates with an impression when the duck is deployed. However, when there is a duck rebound, locking is not ensured and the duck can remain in the partially deployed position.

We also know by FR-2241761 a projectile equipped with a deployable rear stabilizer stabilizer. Each wing of the empennage is deployed by means of a spring. However, such a tail is fixed after deployment. The positioning of the spring relative to the fin and the locking mode of the fin by the spring are such that this solution could not be adapted to a pilot blade pivotable relative to an axis perpendicular to the axis of the projectile.

The invention aims to provide a device for opening and locking duck fin to make both the opening and the locking of the fin reliable.

Thus, the subject of the invention is a device for opening and locking a duck wing for a projectile according to claim 1.

According to one embodiment of the invention, the support finger is constituted by a loop of a spiral spring disposed about an axis parallel to the axis of deployment of the fin and disposed at a distance from the latter.

According to one feature, in the deployed position, the loop of the spiral spring is substantially perpendicular to the axis of the deployed fin.

Advantageously, the spring will comprise two spirally wound parts connected by a loop comprising an end strand, each part being arranged around an axis disposed in a housing of the projectile body, the two axes being aligned along a geometric axis which is parallel to the axis of deployment of the fin and disposed at a distance from the latter.

The axes receiving the spiral parts may include a threaded portion cooperating with a tapping of the body and an eccentric portion relative to the threaded portion and which is housed within the spiral portion considered.

According to another embodiment of the invention, the support finger is constituted by the end of a lever pivotally mounted relative to an axis parallel to the axis of deployment of the fin.

According to one feature, in the deployed position, the end of the lever forms with the outer surface of the arm an obtuse angle.

The lever will switch as a result of the action of at least one compression spring and may exert on the fin a pivoting torque.

A position sensor may be disposed near the support finger and will detect the passage of the latter to its locking position of the fin.

• les figures 1a et 1b montrent un premier mode de réalisation du dispositif selon l'invention en position fermée, la figure 1a étant une vue en perspective partielle et la vue 1b une vue en coupe partielle,
• les figures 2a et 2b montrent ce premier mode en position semi-ouverte, la figure 2a étant une vue en perspective partielle et la vue 2b une vue en coupe partielle,
• les figures 3a et 3b montrent ce premier mode en position ouverte, la figure 3a étant une vue en perspective partielle et la vue 3b une vue en coupe partielle,
• la figure 4 est une vue du levier seul,
• les figures 5a et 5b montrent un deuxième mode de réalisation du dispositif selon l'invention en position fermée, la figure 5a étant une vue en perspective partielle et la vue 5b une vue en coupe partielle,
• les figures 6a et 6b montrent ce deuxième mode en position semi-ouverte, la figure 6a étant une vue en perspective partielle et la vue 6b une vue en coupe partielle,
• les figures 7a et 7b montrent ce deuxième mode en position ouverte, la figure 7a étant une vue en perspective partielle et la vue 7b une vue en coupe partielle,
• la figure 8 est une vue du ressort spiral seul.

The invention will be better understood on reading the following description of various embodiments, description made with reference to the accompanying drawings and in which:

• the Figures 1a and 1b show a first embodiment of the device according to the invention in the closed position, the figure 1a being a partial perspective view and the view 1b a partial sectional view,
• the Figures 2a and 2b show this first mode in semi-open position, the figure 2a being a partial perspective view and the view 2b a partial sectional view,
• the Figures 3a and 3b show this first mode in the open position, the figure 3a being a partial perspective view and the view 3b a partial sectional view,
• the figure 4 is a view of the lever alone,
• the Figures 5a and 5b show a second embodiment of the device according to the invention in the closed position, the figure 5a being a partial perspective view and the view 5b a partial sectional view,
• the Figures 6a and 6b show this second mode in semi-open position, the figure 6a being a partial perspective view and the view 6b a partial sectional view,
• the Figures 7a and 7b show this second mode in the open position, the figure 7a being a partial perspective view and the view 7b a partial sectional view,
• the figure 8 is a view of the spiral spring alone.

The Figures 1a to 3b thus show a first embodiment of a duck deployment device according to the invention.

The outer shell of the projectile 1 was removed and partial cuts were made to allow visualization of the device.

The projectile 1 carries four duck wings 2, only one of which is shown in the figures. Each fin has a bearing surface 2a which is integral with an arm 2b articulated with respect to a deployment axis 3 which is perpendicular to the axis 4 of the projectile. The deployment axis 3 is integral with a drive yoke 5 which is itself pivotally mounted relative to the body 7 of the projectile 1, and along an axis 6, called the control axis, which is one axis at a time. perpendicular to the axis 4 of the projectile and to the axis of deployment 3.

Once in the deployed position ( Figures 3a, 3b ) the fin 2 may pivot about this axis 6, driven by the yoke 5, itself driven by a motor (not shown).

The drive means of the yoke 5 and the fin 2 are not the subject of the present invention and they will not be described in detail. We can refer to the patent EP1772698 which describes the drive means which is implemented here.

We can simply note that the 8 ( figure 1b ) shows a lever for controlling the pivoting of the yoke 5 from a geared motor.

The deployment device here comprises a first motor means pivoting the duck fin 2 relative to its yoke 5. This means is constituted by a spiral spring coaxial with the axis 3 and which has the effect of exerting on the fin 2 a pivoting torque which brings it from its folded position (Figure la) to its deployed position ( figure 3a ).

The motor means also comprises another means exerting a pivoting torque on the fin 2.

This other motor means is constituted by a lever 9 which is pivotally mounted relative to an axis 10 parallel to the axis 3 of deployment of the fin.

The figure 4 shows in isolation and in perspective the lever 9. The lever comprises two branches 9a, 9b separated by a slot 11 which allows the passage of the bearing surface 2a of the fin 2. The branches meet at the end of the lever 9 to form a support finger 12.

The support finger 12 is in the folded position of the device ( Figures 1a, 1b ), directly in contact with the outer surface of the arm 2b and away from the deployment axis 3.

Furthermore, two compression springs 13 exert a thrust at a bulge 14 of each leg of the lever 9. These springs 13 are just positioned in the figures to locate their location. They are arranged in holes integral with a part of the projectile body. We have shown on figures 2b and 3b the holes by dotted line 15 as well as the part 16 of the projectile body receiving these bores.

The holes guide the springs 13 during their compression and the bottom of each hole forms a bearing surface for the spring.

Thus, when the fin 2 is in its folded position ( Figures 1a, 1b ), the lever 9 compresses the springs 13. The latter exert a force on the lever 9 which exerts (by the support finger 12) a pivoting torque directly on the arm 2b of the fin and at a distance from the axis 3 and the yoke 5, and without touching the bearing surface 2a.

The lever thus completes the torsion spring surrounding the axis 3 and thus provides assistance with the deployment of the fin 2.

The Figures 2a and 2b show an intermediate step of the deployment of the fin 2.

It can be seen in these figures that the bearing finger 12 follows the outer surface of the wing arm 2b and continues to exert a pair helping to pivot the fin 2 relative to the axis 3.

The Figures 3a and 3b finally show the fin 2 in the deployed position. In a conventional manner, the fin 2 comprises a locking means consisting of a slide pin 17 pushed by a spring (not visible in the figures) and which cooperates (in the deployed position of the fin) with a notch 18 ( Figures 1a, 1b and 3a ) carried by the yoke 5. The pin 17 is disposed in a housing of the arm 2b of the fin. It is kept erased inside its housing by bearing surfaces integral with the projectile body (and not visible in the figures which include partial sections of the projectile body to see the different organs). The pin 17 enters the notch 18 only when the fin is in the deployed position.

According to another characteristic of the invention when the lever 9 is in the deployed position ( Figures 3a, 3b ) its end 12 (bearing finger) forms a locking stop for the arm 2b.

We see on the figure 3b that the end 12 of the lever 9 is inclined relative to the lever 9 itself. It thus forms with the outer surface of the arm 2b an obtuse angle β (greater than 90 °) which makes irreversible deployment. Once deployed, the arm 2b of the fin can no longer rotate the lever 9. The angle β could possibly be equal to 90 °. Only angle values below 90 ° could make the deployment reversible. Such a value of the angle P also makes it easier to integrate. We notice indeed that in folded position ( figure 1b ) the end 12 of the lever is substantially parallel to the axis 4 of the projectile. This avoids any mechanical interference in this folded position.

An obtuse angle β finally makes it possible to increase the distance between the support zone of the end 12 on the arm 2b and the deployment axis 3. An increase in this distance makes it possible to reduce the angular clearance of the deployed winglet relative to its deployment axis 3.

The end 12 of the lever 9 secures the lock. Indeed, it prevents any rebound of the fin 2 when it arrives in the deployed position.

We also note on the figure 4 that the end 12 of the lever comprises a cylindrical profile 12a which is intended to cooperate with a complementary profile of the arm 2b. Thus the arm 2b can rotate freely about the axis 6 once the wing deployed to allow the steering of the projectile. The locking abutment formed by the end 12 of the lever 9 does not interfere with the operation of the pilot blade duck 2.

It is represented by a dotted circle 19 on the figure 3b the location of an inductive position sensor.

When the lever 9 adopts its locking position ( figure 3b ) its end 12 is detected by the sensor 19. This sensor is connected to the guidance / steering electronics of the projectile. The detection signal is used to validate the subsequent operation of the projectile.

This detection means is more reliable than the one known hitherto. Indeed it was known to detect the deployment of the fin by a detection of the absence of the fin (exit of the fin outside the projectile body).

However, such detection has insufficient accuracy. The fin may actually be out of the projectile body without being properly locked in the deployed position.

The device according to the invention detects, not the exit of the fin from the projectile body, but the locking of this fin. The detection is also by locating the position of a metal element (the support finger 12) of relatively small thickness which improves the accuracy of the detection.

The Figures 5a to 7b show a second embodiment of a duck fin deployment device according to the invention.

This mode differs from the previous one only in the structure of the motor medium.

This means comprises here (in addition to the spiral carried by the axis 3) a double spiral spring 20. This spring is represented alone and in perspective on the figure 8 .

It comprises two parts 20a and 20b wound in a spiral and connected by a loop 21 having an end strand 21a. The spiral portions 20a and 20b are each disposed about an axis 22a, 22b which is disposed in a housing of a portion (not shown) of the projectile body. The two axes 22a and 22b are aligned along a geometric axis 23 which is parallel to the axis 3 of deployment of the fin and disposed at a distance from the latter.

The axes 22a, 22b advantageously comprise a threaded portion cooperating with a tapping of the body and an eccentric portion relative to the threaded portion and which is housed within the spiral portion 20a or 20b considered. Thus by screwing each axis can move slightly longitudinally each spiral portion.

Such an arrangement facilitates assembly by allowing a final adjustment of the position of the loop 21 relative to the arm 2b of the fin.

The free ends 24a, 24b of the spiral portions 20a, 20b are integral with the projectile body. The bearing surface 2a of the fin 2 passes between the two spiral portions 20a and 20b.

As this is particularly visible on the figure 5b , the end portion 21a of the loop 21 of the spiral spring 20 is in abutment against the outer surface of the arm 2b of the fin. This strand 21a forms the bearing finger which exerts a pivoting torque on the arm 2b of the fin.

• Les figures 6a et 6b montrent l'ailette dans une position intermédiaire de déploiement. On voit sur ces figures que le brin 21a du ressort 20, formant doigt d'appui, suit la surface externe du bras 2b de l'ailette et continue à exercer un couple aidant au pivotement de l'ailette 2 par rapport à l'axe 3.
• Les figures 7a et 7b montrent enfin l'ailette 2 en position déployée.

In this folded position ( figure 5b ) the arm 2b of the fin forces the spring 20 in torsion. The torque exerted by the latter is therefore maximal.

• The Figures 6a and 6b show the fin in an intermediate deployment position. It can be seen in these figures that the strand 21a of the spring 20, forming a bearing finger, follows the external surface of the arm 2b of the fin and continues to exert a torque helping the pivoting of the fin 2 relative to the axis 3.
• The Figures 7a and 7b finally show the fin 2 in the deployed position.

As in the previous embodiment, the strand 21a constitutes a locking abutment for the arm 2b of the fin. It can be seen in these figures that the spring 20 in its rest position has its loop 21 substantially parallel to the axis 4 of the projectile. The end portion 21a of the loop 21 is then in contact with the arm 2b.

End strand 21a is tangent to the outer surface of arm 2b. The latter can rotate freely around the axis 6 once the wing deployed to allow the steering of the projectile. The locking abutment formed by the end strand 21a of the loop 21 of the spring 20 does not interfere with the operation of the piloting duck fin 2.

Moreover, the orientation of the loop 21 substantially perpendicular to the axis 6 of the deployed wing (see Figures 7a and 7b ) prohibits any return back of the arm 2b to compress the spring 20. Again the deployment of the fin is again irreversible.

Such an arrangement secures the locking by preventing any bounce of the fin when it arrives in the deployed position.

Note that the geometric axis 23 of the spring 20 around which are positioned the spiral portions 20a and 20b is located behind the deployment axis 3 of the fin 2 and at a distance from the latter ( figure 7a ). Furthermore, the bearing surface 2a of the fin 2 is housed between the two spiral parts 20a and 20b in the closed position ( Figures 5a and 5b ) and stays between these two spiral parts during deployment ( Figures 6a, 6b ). There is therefore no interference between the spring 20 and the fin during the deployment of the vane and the pivoting thereof around its axis 6 in the deployed position. The only relative contact spring 20 / fin 2 is at the arm 2a by the support of the strand 21a which helps the deployment and ensures a rebound lock.

As in the previous embodiment, an inductive position sensor 19 has been put in place.

This sensor 19 detects the passage of the loop 21 of the spring 20 to its locking position ( figure 7b ). This accurately and reliably detects the locking of the fin in the deployed position.

As a variant, it would of course be possible to modify the dimensions of the means described (spring or lever). It would also be possible to implement a lever 9 having only one branch or a spiral spring 20 having only one spiral loop.

Motor means associating a main means consisting of a hairspring coaxial with the deployment axis 3 and a complementary means consisting of a lever 9 or a double hairspring 20 have previously been described.

It is of course not possible to provide a hairspring coaxial with the deployment axis 3. In this case the motor means ensuring deployment without rebound are constituted solely by the lever 9 or by the double hairspring 20.

Such embodiments are possible if the integration constraints in the projectile allow the installation of springs 13 or 20 having a stiffness sufficient to allow deployment.

Claims (9)

1. An opening and locking device for a canard fin (2) for a projectile (1), such fin comprising an airfoil (2a) integral with an arm (2b) hinged with respect to a deployment pin (3) perpendicular to the projectile axis (4), such deployment pin (3) being integral with a drive coupling (5) itself able to pivot around an axis (6) called the steering axis which is both perpendicular to the projectile axis (4) and to the deployment pin (3), device comprising at least one motor means to pivot the fin (2) from a stowed position inside the projectile body to a deployed position substantially radial to the projectile body, the motor means comprising a contact finger (12, 21) exerting pivoting torque directly on the arm (2b) and at a distance from the deployment pin (3), the contact finger further constituting a locking stop for the arm (2b) when the fin (2) is in its deployed position, device characterized in that the contact finger is integral with the projectile body by a pin (10, 22a, 22b) parallel to the deployment pin (3) of the fin, the pressure of the finger (12, 21) on the arm (2b) being oriented such that deployment is irreversible, this contact leaving the deployed fin free to subsequently pivot following the steering axis (6).
2. An opening and locking device according to Claim 1, characterized in that the contact finger is constituted by a loop (21) of a spiral spring (20) arranged around a pin (23) parallel to the deployment pin (3) of the fin and arranged at a distance from the latter.
3. An opening and locking device according to Claim 2, characterized in that, in the deployed position, the loop (21) of the spiral spring (20) is substantially perpendicular to the axis (6) of the deployed fin.
4. An opening and locking device according to one of Claims 2 or 3, characterized in that the spring (20) comprises two parts (20a, 20b) wound into a spiral and linked by a loop (21) incorporating an end strand (21a), each part (20a, 20b) being arranged around a pin (22a, 22b) arranged in a housing of the projectile body, the two pins (22a, 22b) being aligned with a geometric axis (23) that is parallel to the deployment pin (3) of the fin and arranged at a distance from the latter.
5. An opening and locking device according to Claim 4, characterized in that the pins (22a, 22b) receive the spiral parts (20a, 20b) incorporating a threaded part cooperating with a female thread in the body and a part that is offset with respect to the threaded part and housed inside the spiral part (20a, 20b) in question.
6. An opening and locking device according to Claim 1, characterized in that the contact finger is constituted by the end (12) of a lever (9) mounted able to tilt with respect to a pin (10) parallel to the deployment pin (3) of the fin.
7. An opening and locking device according to Claim 6, characterized in that, in the deployed position, the end (12) of the lever (9) forms an obtuse angle (p) with the external surface of the arm (2b).
8. An opening and locking device according to one of Claims 6 or 7, characterized in that the lever (9) tilts further to the action of at least one compression spring (13) thereby exerting on the fin (2) a pivoting torque.
9. An opening and locking device according to one of Claims 1 to 8, characterized in that a position sensor (19) is arranged near to the contact finger (12, 21) and detects the movement of the latter into its fin locking position.

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