FR2999640A1 - ELECTROMECHANICAL ACTUATOR, CLOSURE OR SOLAR PROTECTION PLANT COMPRISING SUCH ACTUATOR AND METHOD FOR CONTROLLING SUCH ACTUATOR - Google Patents

Abstract

This electromechanical actuator for the motorized control of a mobile screen (10) comprises a motor providing a movement (R5) to a kinematic chain comprising at least one gearbox, a transmission shaft of the movement supplied by the motor, a piece of input (60) and an output piece (70) movable relative to each other on a limited stroke. This actuator further comprises an obstacle generating device comprising at least one obstacle element (72-1, 72-2) capable of creating a transient force resistant to the transmission movement between the input piece and the workpiece. output, and means for detecting the transient resistant force.

Description

The invention relates to the field of electromechanical actuators for motorized control of the occultation or sun protection elements in a building, such as electromechanical actuators, and a method for controlling such an actuator. only blinds or shutters. Such actuators move a concealment element, or screen, by means of a winding shaft, on which the screen is wound directly, of the flap or flexible fabric type, for example, or cords. linked to a free end of the screen, in the case of blinds called pleated or Venetian particular. Actuators must fulfill a number of criteria for their optimal operation. In particular, they must be aware of the position of the screen and must be able to stop in particular positions.

An additional advantageous criterion, particularly related to shutter type screens, is the ability to stop at any position of the race due to an obstacle present in the path of the shutter. In the devices of the prior art, it is known to monitor certain parameters, such as the engine torque, torque variations, speed or speed variations, in order to detect the appearance of an obstacle on the trajectory of the engine. screen, triggering the engine stop. The difficulty of its solutions lies in the fact that, in the case of blinds with blades, the obstacle can be detected only after a large stacking of the shutter blades, corresponding to the catch-up of the games of the screen, or even after a unwinding the blades in the box. There is therefore a need for a solution for finer and faster detection of the obstacles present during a shutter run. In the case of awnings with flexible fabric that take place under the action of a weighted load bar, it is difficult to detect the presence of an obstacle in the path of the fabric, which can not mechanically transmit the information to the actuator. Solutions with a remote sensor exist. The remote sensor must necessarily be powered, either autonomously by a battery, or by a cable running along the screen. The information detected by the sensor must be transmitted to the actuator. The routing of power and information is a constraint, especially in terms of installation, lifetime or reliability.

Other known solutions aim at integrating the obstacle generation function at the level of the actuator, for example by placing a clearance between two parts of the actuator itself, or at the end of the actuator. . A sensor then determines the relative position of the two moving parts. However, there are connection problems for the power supply and the transmission of information between the sensor and the engine control unit. In addition, the activation of the sensor requires a complete catching of the game, which is equivalent to a consequent stacking of many blades of the deck or a significant wrinkling of the fabric. Moreover, these various solutions pose problems in terms of service life of moving parts and components. They are not suitable for soft fabric blinds.

The invention therefore proposes to provide an alternative to existing devices and an improvement thereof to allow fine obstacle detection on the deployment path of a roller shutter. In particular, the invention proposes an obstacle generation device using a majority of mechanical components whose resistance in time is known and which allow a complete independence vis-à-vis the operating parameters of the engine, in particular the actuator power supply, or surrounding parameters such as temperature or travel time. The device according to the invention also makes it possible to detect the occurrence of an obstacle in a zero load zone, preferably even before the load, seen by the engine, is canceled by passing driving load led load. This has the advantage of not forcing the engine to exert a greater torque for the passage of a blocking point in full stroke. For this purpose, the invention relates to an electromechanical actuator for the motorized control of a mobile screen, the actuator comprising a motor providing movement to a kinematic chain comprising at least one gearbox, a transmission shaft of the movement supplied by the motor. , an input piece and an output piece movable relative to each other on a limited stroke. This actuator is characterized in that it comprises: an obstacle generating device comprising at least one obstacle element, capable of creating a transient force resistant to the transmission of movement between the input piece and the output piece and a means for detecting the transient resistant force. Thanks to the invention, a transient obstacle in the path of the screen can be detected reliably and quickly based on a transient resistant force generated by the obstacle element.

According to advantageous but non-obligatory aspects of the invention, such an actuator can incorporate one or more of the following characteristics: the obstacle element creates the transient force resistant to a substantially zero load, in particular when the state passes driving charge in the state of charge. - The obstacle element creates the transient resistant force by moving between a first position, where it does not affect the motion transmission between the input piece and the output piece, and a second position, where it brakes the exit piece. - The displacement of the obstacle element between its first position and its second position takes place in a radial direction relative to an axis of rotation of the transmission shaft. The obstacle generating device is included in an element of the kinematic chain. - The obstacle generating device is included in the drive train upstream of the gearbox. - The obstacle generating device is included in an accessory placed at the output of the actuator, on the transmission shaft. The means for detecting the transient resistant force is common to a detection element of an operating parameter of the motor. - The means for detecting the transient resistant force is offset along the kinematic chain, relative to the engine. The actuator comprises at least two obstacle elements, each adapted to create a transient force resistant to the transmission of movement between the input piece and the output piece respectively in a first direction and in a second direction. - The two obstacle elements are placed in the same plane perpendicular to a longitudinal axis of the actuator. The actuator comprises several active obstacle elements in each direction of movement. - The actuator includes several obstacle generating devices placed at different locations along the drive train. - The actuator comprises means for returning the transient obstacle element 30 to an initial position in which it is again able to create a transient resistant force that changes the transmission of movement between the input part and the workpiece of exit, without creation of a new transient resistant force during the return of the obstacle element in the initial position. The invention also relates to a closure or solar protection installation which comprises, inter alia, an occultation screen and an actuator as mentioned above.

Finally, the invention relates to a method for controlling the operation of an actuator, in particular an actuator as mentioned above, this method comprising the steps of: a) - generating a retaining torque for retaining the movable element as a driving load, b) - generating a transient drive torque in response to a transient force load, for driving the input part and the output part, c) - detecting the transient drive torque, (d) - determining a charge driving charge passage conducted when the transient driving torque takes a zero value after taking a non-zero value. Advantageously, provision may be made for an additional step e) consisting in: determining, from the driven load driving charge passage, the fact that an obstacle has been encountered by the occultation screen or an associated direction of rotation to the kinematic chain. According to another advantageous aspect, the method may comprise a step f) during which the detection of the transient drive torque is ignored, in particular during non-steady state operation. The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of two embodiments of an actuator and an installation in accordance with its principle, given solely for example and with reference to the drawings in which: - Figure 1 is a partial longitudinal section and principle of an installation according to the invention; - Figure 2 is a section of principle along line II-II in Figure 1 when the installation is in a first use configuration; - Figures 3 to 7 are sections similar to Figure 2 when the installation is in other configurations of use; FIG. 8 is a representation as a function of time of the value of the torque delivered by a motor of the installation of FIGS. 1 to 7; FIG. 9 is a partial exploded perspective view of an actuator according to a second embodiment of the invention; - Figure 10 is a cross section of the actuator of Figure 9; and FIG. 11 is a partial perspective view of the actuator of FIGS. 9 and 10.

FIG. 1 represents a plant 100 comprising a tubular actuator 1 for maneuvering a closure, occultation, sun protection or screen device. The tubular actuator 1 comprises a fixed point or head 2, a tubular body 3 and an output shaft 4 rotatable about a central axis X-X 'of the tubular body 3, which is horizontal when the installation is in use. The output shaft 4 is connected to a winding tube 5, in which the actuator is engaged, by a drive wheel 6. A bearing 7 allows the rotational guidance of the winding tube on the tubular body of the actuator. An attachment accessory 8 connects the fixed point 2 to a frame 9 such as a window frame. A windable element 10, shown in phantom, is fixed by one of its ends to the winding tube, the windable element occulting the window when it is unwound. The windable element may be a shutter, a screen, a grid, a fabric, or a cord or any other mobile screen for concealment or closure. The fixed point 2, otherwise called the "head" of the actuator, is an end piece that supports a portion of the weight of the actuator 1, the winding tube 5 and the windable element 10 and which fully supports the torque of the actuator. The fastening accessory 8 connecting the fixed point or head 2 to the frame is able to be fixed firmly to the frame. The connection of the head 2 to the attachment accessory 8 is, in turn, preferably removable, that is to say easily locked or unlocked, so as to facilitate the installation or maintenance of the windable element 10 or actuator 1. For this purpose, specific fastening elements are used, which comprise for example elastic clipping means and shapes adapted to the simultaneous recovery of weight and torque. These fixing elements are included or not in the accessory 8 and / or in the head 2. In the example shown schematically in Figure 1, the head 2 is connected without play to the tubular body 3. It comprises for this purpose a tubular portion The head and the tubular body are fixed axially to one another by means of a screw or by clipping, which is not shown. The tubular body 3 also comprises at least one lumen 30 at a first end, cooperating with a longitudinal shoulder or longitudinal boss 24 provided on the tubular portion 20 of the head. In this way, the tubular body 3 can not move angularly vis-à-vis the head 2 and the boss allows, in cooperation with the light, the torque recovery to the head of the actuator. The head 2 is also mounted without play in the attachment accessory 8. An asynchronous motor 50 and a control module 40 for controlling the motor 50 are housed inside the tubular body 3. The motor 50 can be current continuous or alternating, with or without brush.

The control module comprises means 41 for controlling the motor 50, such as, for example, a counting device and a motor variable monitoring module, such as the position and / or the torque. This monitoring module notably allows the automatic stop at the end of the stroke or in the intermediate position of the windable element 10 or the automatic stopping of the motor 50 in response to the presence of an obstacle. The control means 41 also comprise a specific module capable of executing a particular engine control program, in particular as a function of the variables monitored. The control means 41 are shown in Figure 1 schematically by an electronic assembly representing the various electronic components, mounted on an electronic card 42, for example a printed circuit. The control means may also comprise one or more sensors for parameters external to the engine, in particular an accelerometer, the dies of which are used by the monitoring module. One end of this electronic card 42 can be embedded in the head 2 for its maintenance or, as shown, the control module can be held by a support 43, also called bathtub, itself maintained relative to the tubular body 3 and / or at the head 2. The tracks of this card 42 are electrically connected, by means of connectors not shown, to a wired link 44. The wired link 44 makes it possible to supply the electronic card and the motor electrically via the module ordered. A not shown cavity is provided in the head 2 for the passage of the wire connection 44. The actuator 1 comprises, in addition to the motor 50, a brake 51 and a gearbox 52. The elements 50, 51 and 52 form with the shaft 4 a kinematic drive chain of the wheel 6 located inside the tubular body 3. The reducer is epicyclic type and comprises several reduction stages. The brake is, for example, a spring-type brake, as described in EP-B-2267330 or EP-B-2230415. The actuator 1 also comprises a transient obstacle generating device, represented by the reference 53. The transient obstacle generating device is included in the brake 51 in FIG. 1, and therefore disposed upstream of the gearbox 52. alternatively, be included in another element of the kinematic chain between the head 2 of the actuator and the output shaft 4 or between two elements of this kinematic chain having between them a running clearance. Other embodiments are therefore possible with respect to the embodiment of FIG. 1. In particular, the transient obstacle device 53 could be made in the manner of an accessory, which could be mounted between the head of the actuator 2 and the accessory 8 for fixing to the frame. Figures 2 to 7 provide a simplified schematic representation of the various moving parts during a displacement of the load constituted by the windable element10 and represented by the black square. The obstacle generating device 53 comprises a friction drum 59 in which an input piece 60 and an outlet piece 70 are housed. The parts 60 and 70 therefore also belong to the kinematic chain mentioned above. The input piece 60 comprises a central portion 61 extending axially along the axis XX 'thereof having two bumps 62-1 and 62-2 on its outer radial surface, these bumps being substantially opposite diametrically with respect to the axis XX 'with a slight shift of the two bumps on the same side of the diameter, and symmetrical in a plane perpendicular to the diameter in question. In a plane perpendicular to the axis X-X 'such that that of Figure 2, each boss comprises a radial surface relative to the axis X-X' and a surface inclined relative to this axis. On the axial extension 61 of the input part 60 are also mounted two activation tabs 64-1 and 64-2, which allow the output piece 70 to be driven in rotation. The output piece 70 is provided by example in the form of a tray, comprising two housings 74-1 and 74-2 in which the activation tabs 64-1 and 64-2 can move in rotation with an angular stroke of limited amplitude, thus forming a connection with rotating game. Obstacle elements, in the form of two cams 72-1 and 72-2, are mounted on the outlet piece 70 with the possibility of limited displacement in translation and in rotation, as represented respectively by the arrows F1, F2, R1 and R2. In the plane of Figure 2, each cam comprises a rounded surface and a rectilinear surface. The cams 72-1 and 72-2 cooperate or not with the bumps 62-1 and 62-2 in the direction of rotation of the input piece 60 vis-à-vis the output piece 70. Each bump cooperates so with a cam and the device 53 is symmetrical in that it can operate for an actuator 1 mounted on the right as on the left of a window frame for which, depending on the mounting side, the directions of rotation corresponding to the ascent and descent are reversed. Depending on the surfaces of the bumps 62-1, 62-2 and cams 72-1, 72-2 in contact with each other, a cam is pushed radially towards the drum in the direction of the arrow F1 or F2, creating a friction with the drum 59 and therefore a force resistant to movement, while the other cam is simply tilted in the direction of the arrow R1 or R2 to release the passage of the corresponding bump. This situation is temporary.

More specifically, if one of the bumps 61-1 or 62-2 comes into contact with one of the cams 72-1 or 72-2 by pressing its inclined surface against the rounded surface of the cam, then the cam is pushed radially outwardly with respect to the axis X-X ', in the direction of the arrow F1 or F2. In the case where a boss 62-1 or 62-2 comes, by its radial surface, in contact with the straight surface of one of the cams 72-1 or 72-2, this cam is rotated in the direction of the arrow R1 or R2. Figure 2 shows a load movement situation 10 driven upwards, or conducted as represented by the arrow F3. The central input piece 60 rotates in the direction of the arrow R3 and drives the outlet piece 70 by cooperation of the activation tabs 64-1 and 64-2 with the edges of the housings 74-1 and 74-2 of the exit room. The bumps 62-1 and 62-2 and the cams 72-1 and 72-2 do not come into contact. When stopped, possibly at the end of the high stroke, represented by FIG. 3, the input piece 60 holds the load 10 by blocking the outlet piece 70, in particular through the brake 51 which is not visible on this figure.

When a descent order is given, the actuator at least partially releases the brake 51 and the load 10 becomes driving, or driving, moving downwards, in the direction of the arrow F4. The outlet piece 70 then rotates in the direction of the arrow R4, the opposite of that of the arrow R3, by driving the input piece 60 through the activation tabs. The load 10 descends in the direction of the arrow F4 and the motor 50 generates a load retaining torque 10 through the drive train. The two input and output parts do not move relative to each other. The bumps and cams are in their so-called initial configuration, without contact between them. This situation is represented in FIG. 4. If the load 10 comes to lock on an obstacle, the stacking of the blades temporarily creates a zero load situation represented in FIG. 5. At this moment, the output piece 70 is more driven by the load. The motor 50 then resumes a motor operation and the input piece 60 rotates in the direction of the arrow R5 which is the same as that of the arrow R4. It comes of itself to catch the angular clearance with the output piece 70. During this movement, the activation tabs 64-1 and 64-2 move in rotation inside the housings 74-1 and 74-2 and the bump 62-1 is repelled, radially relative to the axis X-X ', the corresponding cam 72-1 to the drum 59, in the direction of the arrow F1, while the other cam 72 -2 is tilted in the direction of the arrow R2 by the boss 62-2, without touching the drum. The pushed cam 72-1 rubs against the drum 59 as shown in FIG. 5, which slows down the rotation of the outlet piece 70. The pushed cam 72-1 thus creates a temporary obstacle or CLOC to the movement of the workpiece. exit 70.

When the entry piece 60 continues its movement due to the passage of charge led load, namely when the play between the parts 60 and 70, and the bump 62-1 exceeds the offset cam 72-1 , the latter resumes its initial configuration under the effect of a return spring not visible in Figures 2 to 7, thus removing the temporary obstacle or CLOCK created by the frictional force of the cam 72-1 against the drum 59. This situation is represented by FIG. 6, where the activation tabs have tilted angularly inside the housings 74-1 and 74-2, with respect to the configuration of FIG. 4. The passage of the configuration of the Figure 5 to that of Figure 6 takes place, in particular, under the effect of not shown springs, without a new transient resistant force is created or considered, when returning the cam 72-1 in its initial position. The friction force generated between the cam 72-1 and the drum 59 is transient, since it is present only when the boss 62-1 pushes the cam in the direction of the arrow F1. This effort is opposed to the transmission of movement between the parts 60 and 70 since it brakes the part 70. The temporary appearance of the friction force caused by the cam 72-1 pushed back can be detected by a measurement of the torque C that must generate the motor 50 to drive the parts 60 and 70. The detection of the particular signature of this couple, as shown in Figure 8, allows to deduce an order S stopping the engine 50. This analysis is carried out by the control means 41 which are able to determine the torque generated by the motor 50 from, in particular, the current and the supply voltage that precisely delivers the module 40 or variations thereof. FIG. 8 schematically shows the torque curve C as a function of the time t seen by the motor 50, whereas the torque at the output of the actuator 1 varies around a zero value, during the passage of the element d temporary obstacle. The periods PO and P5 correspond to the torque C when the obstacle elements, namely the set of cams 72-1 and 72-2, are not solicited. The period P1 represents the beginning of the friction of a cam against the drum, when one of the cams is to be repelled by the passage of the corresponding bump. Period P2 represents the friction created by maintaining the cam in the direction of the drum throughout the passage of the bump. The periods P3 and P4 show the return to a rest position of the cam following the passage of the bump beyond the cam, taking into account the inertia of the engine, which provided a given torque for the crossing of the cam. transient obstacle, returns to a pair of equilibrium represented by the value Co in FIG.

Thus, by detecting the period P1 to P5 in which the motor 50 is operating, it is possible for the means 41 to determine whether a transient resistant force has been and / or is generated by one of the cams 72-1 and 72-2, that is, if a temporary obstacle was encountered and / or crossed during the lowering of the load 10.

The following method can in practice be implemented: in the configuration of FIG. 4, the actuator 1 is driven to generate a retaining torque of the parts 60 and 70, allowing movements in the direction of the arrows F4 and R4. When an obstacle is present on the lowering path of the load 10, the cam 72-1 reaches the drum 59, as shown in FIG. 5. The driving of the parts 60 and 70 imposes to increase the torque delivered by the motor. 50. This increase takes place until reaching a maximum torque C1, at the end of the period P1, then by applying a bearing pair C2 over the period P2. Bearing torque C2, which is a transient drive torque used to react to the transient force resulting from the friction of the cam 72-1 against the drum 59, is mainly considered. This transient drive torque C2 can be detected by the means 41. If the obstacle disappears, for example because of its withdrawal, the load 10 becomes catchy again. The output piece 70 is again driven and recreates a game with the input piece 60. The bumps and cams then resume their initial configuration, so as to have the same behavior on the rest of the downward movement. During this movement which takes place out of control of the behavior of the motor 50, the possible friction of one of the cams 72-1 and 72-2 against the drum 59 is not analyzed. If the obstacle is similar to a stop, that is to say it does not disappear, the next movement is a climbing movement, which also comes to replace the bumps and cams in their initial configuration, as shown in FIG. Figure 7.

In the configuration of FIG. 7, the obstacle generating device 53 is in fact rearmed, in that the load 10 is lifted in the direction of the arrow F6, by means of a rotation of the driving part. 60 in the direction of the arrow R6, about the axis X-X '. In this case, the cam 72-2 comes into contact with the drum 59, which induces a transient resistant force for the same reasons as those explained above. This induces the generation of a transient drive torque, comparable to the C2 pair, but it is not taken into account to determine that an obstacle has been encountered because it is there in a regime not established. Thus, it is possible to associate the temporary torque variation C, especially the creation of the transient torque C2, with the only driven load driving passage, even though the torque generated by the actuator is close to zero.

Returning to the case of an established regime, as mentioned above with reference to FIGS. 2 to 6 and 8, it can be considered that the detection of a transient resistant force, corresponding to the braking of the outlet piece 70 by one of the cams 72-1 or 72-2, means that the load 10 has passed from leading to led.

A second embodiment of an obstacle generating device is now detailed with reference to FIGS. 9 to 11. This embodiment is based on a transient obstacle generation device 53 coupled with a spring brake 51. embodiment is advantageous, since it allows pooling some parts of the brake 51 and the device 53 of obstacle generation, such as the input part or the drum. In the following description, the elements of the second obstacle generating device similar to those of the first bear the same references. FIG. 9 shows an exploded view of a braking and detection assembly grouping together the brake device 51 and the obstacle generating device 53. This assembly comprises a drum 59 common to the two devices 51 and 53. A plate 110 corresponds to to the input part of the brake 51 and is rotated by the motor 50. The plate 110 supports the spring brake 51 and also a butterfly 70A actuating the coil spring 120 of the brake 51. The butterfly 70A constitutes the brake output member 51. The brake 51 is as explained in EP-B-2267330 or EP-B-2230415. The butterfly valve 70A comprises a central output shaft 71 as well as lateral lugs 78-1 and 78-2 enabling it to act on the lugs of the helical spring 120, one of these lugs being visible in FIG. 9 with the reference 122 The throttle 70A is driven by the load seen from the brake, especially in the case of a driving load, when the weight of the shutter or a weighted load bar causes the unwinding of the shutter, the engine being driven. The brake 51 also comprises a cover 63, coupled to the plate 110 by screws 65 represented by their center lines and which are engaged in tappings formed in blocks 115, themselves integral with the plate 110 and arranged radially at the end of FIG. Inside the spring 120. Thus, the plate 110 and the lid 63 are integral in rotation about the axis XX 'and together constitute an input part 60 common to the devices 51 and 53. The lid 63 holds the brake parts. 51 axially. It is in the form of a plate including an axial extension 61, directed away from the plate 110 and surrounding the central output shaft 71 of the butterfly 70A. The axial extension is provided with a first bump 62-1 and a second bump 62-2 on its outer surface, these bumps being substantially opposite diametrically, with a slight offset of the two bumps on the same side of the diameter, and symmetrical in a plane perpendicular to the diameter in question. Each boss comprises a first flat surface 62-3, substantially perpendicular to the axial extension 61 and radial relative to the axis X-X ', and a second inclined surface 62-4.

Around the axial extension 61 is also mounted a cam ring 70B driven without play in rotation by the butterfly 70A. The ring 70B is fixed by any known means on the throttle valve 70A, for example fixed in rotation on the central shaft 71 of the throttle valve 70A by means of flats. Thus, the elements 70A and 70B together constitute an outlet piece 70 for the devices 51 and 53.

Furthermore, the cam ring 70B is capable of a rotation movement of limited amplitude relative to the input piece. Indeed, the lateral lugs 78-1 and 78-2 of the butterfly 70 can rotate about the axis X-X ', radially inside the spring 120, in an angular movement limited by the blocks 115. On the 70B ring, a first cam 72-1 and a second cam 72-2 are mounted with the possibility of displacement in translation and rotation. As represented by the arrows F1, F2, R1 and R2. The cams are provided with a first flat surface 72-3 and a second rounded surface 72-4, cooperating respectively with the surfaces 62-3 and 62-4 of the bumps, according to the direction of rotation of the entry piece. 60 or the outlet piece 70. A third friction surface 72-5 joins the other two surfaces, so that each cam has a generally triangular shape. The cams are returned to the rest position by return springs 75-1 and 75-2, themselves resting on abutments 75-3 and 75-4 rigidly mounted on the ring 70B and visible in FIGS. 10 and 11. These springs 75-1 and 75-2 correspond to the unrepresented springs of the first embodiment. Each cam 72-1 and 72-2 is provided with two pins 72-6 which are engaged in grooves 70-6 of the ring 70B, with a possibility of translation in the direction of arrows F1 and F2 and rotation in the direction of the arrows R1 and R2. The ring 70B also carries a first elastic blade 76-1 and a second elastic blade 76-2, which are held on the ring 70B, at one of their ends. The free end 76-3 of the resilient blades is rounded outwardly, thereby forming a friction surface against the drum 59 when the blade is spread toward it. At rest, the elastic blades are spaced apart from the drum, without contact therewith.

Each boss 62-1 or 62-2 cooperates with a cam 72-1 or 72-2. Depending on the surfaces involved, a cam is either pushed by the corresponding boss, radially towards the drum, in the direction of the arrows F1 or F2, thus creating a friction and therefore an obstacle to movement, while the other is simply tilted in the direction of the arrow R1 or R2, to release the passage of the corresponding bump. In the embodiment of the present invention, a cam 72-1 or 72-2 when it is pushed radially, comes into contact with one of the elastic blades 76-1 or 72-1, which itself comes to rub against the drum 59 by its rounded end. Various positions of the bumps and cams are illustrated in Figures 10 and 11. In Figure 10 the rotation of the input piece 60 has brought the bumps and the cams into contact. The first cam 72-1 contacted the first bump 62-1 by their respective flat surfaces 72-3 and 62-3. As a result, the first cam has tilted about its axis of rotation in the direction of the arrow R1. It does not come into contact with the drum 59, nor with the first elastic blade 76-1. In contrast, the second cam 72-2 and the second bump 62-2 slid translationally relative to each other because their inclined surfaces 62-4 and 72-4 were vis-à-vis during the rotation. The second cam has slid radially outwardly relative to the axis X-X ', towards the inner wall of the drum in the direction of the arrow F2. At the time of maximum extension, the second cam is in contact with the second elastic blade 76-2, whose rounded end 76-3 rubs against the inner radial surface of the drum. Figure 11 shows the cams and bumps as they return to their original configuration. None of the two cams no longer press on the corresponding elastic blade, the friction between the latter and the drum is over. The obstacle created by the support of one of the elastic blades on the drum is therefore a transient obstacle, which takes place only at the moment of the passage of the bumps at the cams. This device makes it possible to very accurately detect an obstacle, due to the induced change in driving or driving load at driven or driven load. It also makes it possible to define in a secure manner a direction of rotation of the kinematic chain formed by the motor 50, the brake Si, the gearbox 52 and the shaft 4. In fact, outside the starting zones, the only moment of generation The physics of the torque signal related to the temporary obstacle in the driveline is the charge-led driving charge passage that occurs when stopping on an obstacle or stop during a downward movement. The direction of rotation associated with these conditions therefore corresponds to the direction of descent of the screen 10. The information is also always given during this passage. We can deduce that the direction of movement established corresponding to this passage is that of a descent movement.

The range of adjustment can be as follows: - Mounting of the actuator in the carrier product. - Sequence of any orders, without any time criterion (orders can be spaced in time, with different temperatures). - If the shutter reaches the high stop, the shutdown of the actuator takes place on a predefined overtorque detection. - When the flap is piloted downhill for the first time to the lower stop, it will detect a "CLOC" signal that will indicate the driver load passage and the direction of descent.

In a certain number of cases of reversal of direction, it is possible to observe signals relating to temporary obstacle passages, but these occurring in non-"established" operation after a start-up, they may easily not be taken into account by the software, as is the case for electronic obstacle detection software based on the observation of current or voltage, the peaks observed at startup are not taken into account. For faster detection in the case of a factory setting, it is possible to artificially create an obstacle to the descent, which limits the travel time before the detection of charge-driving load passage conducted. The position of the obstacle generating device 53 in the driveline can be considered in two cases, namely: - a first case, with a gearbox 52 with good efficiency. It is then rather reversible. a second case, with a gearbox 52 with poor efficiency. It is then strongly irreversible.

In the second case, when the load is blocked on an obstacle, the reducer which is highly irreversible brakes itself and triggers the generation of an obstacle, earlier than in the first case where the reducer is rather irreversible. In addition, the response of the motor is also faster to provide a driving torque, this torque being greater than in the first case to compensate for the poor performance. The transition from a driving load situation to a conducted load situation is detectable earlier and more easily in the second case than in the first case. In addition, the actuator can even anticipate the transition to zero load. For these reasons of efficiency, it is also preferable to place the obstacle generating device 53 upstream of the gearbox 52, that is, closer to the engine 50. The obstacle generating device 53 is near the motor 50, compared to the reduction stages, the earlier it will detect the passage at zero load, because of the accumulation of reduction stages between the load and the obstacle generating device 53 and therefore the Increasing the irreversibility of the gearbox 52. According to embodiments not shown, the actuator may comprise several transient obstacle generation devices placed at different locations along the kinematic chain. Alternatively, or in a complementary manner, each transient obstacle generating device may comprise different transient obstacle elements for the same direction of movement. The detection of the charge-driven driving charge passage will then be done not on the detection of the crossing of a temporary obstacle, but on a more complex signature of the torque seen by the actuator, corresponding to the crossing of the various obstacles, in particular with different crossing thresholds. In the two embodiments described above, the two cams 72-1 and 722 can create a transient force respectively when the motor 50 drives the wheel 6 in a first direction or in a second direction. Indeed, the cam 72-1 is active in the configuration of Figure 5 due to the rotation of the input piece 60 in the direction of the arrow R5, which is the same as that of the arrow R4. The cam 72-2 would be active in the case of rotation in the opposite direction. It is the same for the two cams of the second embodiment shown.

In a variant, several obstacle elements of the type of the cams 72-1 and 72-2 may be provided, these different obstacle elements being active in each direction of movement. The invention is described above and shown in the figures in the case where the input piece 60 and the outlet piece 70 are movable relative to each other in a rotational movement of limited amplitude. It is also applicable in the case where these parts are movable relative to each other in a translational movement. The features of the embodiments and alternatives contemplated above may be combined with one another. In this document, the term transient force is understood as a force disappearing when the movement between the input piece and the output piece continues in the same direction.

Claims (18)

REVENDICATIONS1. Electromechanical actuator (1) for the motorized control of a movable screen (10), the actuator comprising a motor (50) providing a movement (R3, R4) to a kinematic chain comprising at least one gearbox (52), a shaft (4) for transmitting the movement provided by the motor, an input piece (60) and an output piece (70) movable relative to each other in a limited stroke, the actuator being characterized in that it comprises: - an obstacle generating device (53) comprising at least one obstacle element (72-1, 72-2), able to create a transient force resistant to the transmission of movement between the workpiece input and the output piece, and - means (41) for detecting the transient resistant force. 2. An actuator according to claim 1, characterized in that the obstacle element (72-1, 72-2) creates the transient force resistant to substantially zero load, in particular the transition from the driving load state to the 'state charge led. 3. Actuator according to one of the preceding claims, characterized in that the obstacle element (72-1, 72-2) creates the transient force resistant moving (F1, F2) between a first position, where it does not affect the motion transmission between the input piece (60) and the output piece (70), and a second position, where it brakes the output piece. 4. Actuator according to claim 3, characterized in that the displacement (F1, F2) of the obstacle element (72-1, 72-2) between its first position and its second position takes place in a radial direction by relative to an axis (X-X ') of rotation of the transmission shaft (4). 5. Actuator according to one of the preceding claims, characterized in that the obstacle generating device (53) is included in a member (51) of the drive train. 6. Actuator according to one of the preceding claims characterized in that the obstacle generating device (53) is included in the kinematic chain upstream of the gear (52). 7. Actuator according to one of the preceding claims, characterized in that the obstacle generating device (53) is included in an accessory placed at the output of the actuator (1), on the transmission shaft (4). 8. Actuator according to one of the preceding claims, characterized in that the means for detecting the transient resistant force is common to a member (41) for detecting an operating parameter of the motor (50). 9. An actuator according to one (50) of claims 1 to 6, characterized in that the means (41) for detecting the transient resistant force is offset along the kinematic chain, relative to the motor (50). 10. Actuator according to one of the preceding claims, characterized in that it comprises at least two obstacle elements (72-1, 72-2), each adapted to create a transient force resistant to the transmission of movement between the inlet part (60) and the outlet part (70) respectively in a first direction (R3) and in a second direction (R4). 11. An actuator according to claim 8, characterized in that the two obstacle elements (72-1, 72-2) are placed in the same plane perpendicular to a longitudinal axis (X-X ') of the actuator. 12. Actuator according to one of the preceding claims, characterized in that it comprises a plurality of obstacle elements (72-1, 72-2) active in each direction of movement. 13. Actuator according to one of the preceding claims, characterized in that it comprises several obstacle generating devices (53) placed at different locations along the kinematic chain. 14. Actuator according to one of the preceding claims, characterized in that it comprises means (75-1, 75-2) for returning the transient obstacle element (72-1, 72-2) to a initial position in which it is again able to create a resistant transient force which modifies the transmission of movement between the input piece (60) and the output piece (70), without the creation of a new transient resistant force when the return of the obstacle element to the initial position. 15. Installation (100) for closing or sun protection comprising an occultation screen (10) and an electromechanical actuator (1) according to one of the preceding claims for driving this screen. 16. A method of controlling the operation of an actuator (1) for controlling the movement of a movable occultation screen (10), the actuator comprising a motor (50) providing a movement (R3, R4) to a kinematic chain comprising at least one input piece (60) and an output piece (70) movable relative to each other on a limited stroke, said method being characterized in that it comprises steps consisting of a) - generating a retaining torque for retaining the movable element as a driving load (10), b) - generating a transient drive torque (02) in response to a transient force load to drive the workpiece input (60) and output piece (70), c) - detecting the transient drive torque, d) - determining a charge driving charge passage conducted when the transient drive torque takes a zero value after have taken a non-zero value (02). 17. Control method according to the preceding claim, characterized in that it comprises a further step consisting in: e) - determining, from the charge led driving charge passage, the fact that an obstacle has been encountered by the occultation screen (10) or a direction of rotation associated with the kinematic chain (4, 50, 51, 52). 18. Control method according to the preceding claim, characterized in that it comprises an additional step of: f) - ignore the detection of the transient drive torque, especially during a steady state operation.