WO2025114469A1 - Actuator for a motorised hatch - Google Patents

Abstract

The present invention relates to a gear motor having a toothed output wheel provided with a ring gear, constituting the last gear stage of the reduction gear of the gear motor, associated with an elastically deformable connecting part, characterised in that: - one of the ring gear or the connecting part has a tubular surface alternating • smooth segments of radius R ₁ each extending over an angle of α degrees and • torque transmission stops of radius R ₂ each extending over an angle of β degrees, the reversal points of which are spaced apart by an angle of α+β degrees, • with R ₁ ≠ R ₂; - the other one of the ring gear or the connecting part having radial protuberances, each supported by a radially elastically deformable zone, able to shift between a radius R ₂ when at rest and a radius R ₁ when the torque applied between the ring gear and the connecting part exceeds a reference value C_max.

Description

Actuator for motorized hatch Field of invention

The present invention relates to the field of rotary mechatronic drive of a mobile member which may occasionally be subjected to inappropriate external forces.

This is for example the drive of a protective hatch for the electric charging socket of an electric vehicle, or a fuel flap, the closing and opening of which are ensured by an actuator, but which the user can close manually, thus causing excessive torque on the drive chain, or a rearview mirror adjustable by an actuator, but which an obstacle can force into a movement which can damage the drive chain, or a vehicle sensor cleaning device activated by an actuator, but which can be driven manually by a user, or a swivel seat whose movement can be either blocked or manually oriented too abruptly or a car door opening handle, the deployment of which is ensured by an actuator, and more generally any organ whose positioning is mainly ensured by a mechatronic system, but which occasionally can be forced into a movement causing excessive torque on the drive mechanism.

The aim of the invention is to protect the mechatronic chain, in particular the gears, some of which are made of medium-strength plastic, as well as the actuator electronics, and optionally to protect the driven member. This aim is fundamentally different from the torque limiters known for limiting screwing forces, particularly in the surgical field, where it is not a question of protecting the drive means, but the driven screw and especially the screw installation area.

State of the art

JP H09 329211 discloses a reduction gear train composed of a plurality of gears is coupled to an output shaft of a motor, and when excessive rotational torque acts on at least one gear of the reduction gear train on the output shaft of the reduction gear train. Motor equipped with a clutch provided with a clutch mechanism that slips and interrupts the transmission of rotational torque on the output shaft side of the motor, wherein the gear provided with the clutch mechanism is a first clutch member, a second clutch member; The clutch member has a cylindrical portion having at least one notch extending in the axial direction and provided with flexibility in the radial direction, and at least one convex portion protruding from the outer surface of the cylindrical portion. In addition, the second clutch member is provided with a concave portion with which the cylindrical portion is engaged, and a grooved portion with which the convex portion is engaged is formed in the concave portion. A pinion, meshing with the gear adjacent to the output shaft side of the motor, is formed on one of the first and second clutch members, and the reducer is formed on the other.

Also known is patent US2020018358 relating to an assembly with overload protection, the elastic element comprises a plurality of protrusions on its circumferential surface, and a plurality of recesses are defined in a lateral surface of the receiving space, each of the protrusions being arc-shaped and defining a concavity, the protrusions are configured to be respectively engaged in the corresponding cavities so as to couple the first gear to the second gear when a torque value is less than a predefined value, and to be disengaged from the corresponding cavities so as to disconnect the first gear from the second gear when the torque value is greater than the predefined value.

Patent EP3767133 relates to an actuator comprising: a housing having a mounting space portion formed therein; a motor portion disposed inside the housing and generating power; a reduction gear portion of which a plurality of gears respectively having an internal gear and an external gear sequentially engage with each other so as to transmit the power generated in the motor portion; and a rod portion engaging with the gear disposed at the last position, and moving linearly according to the rotation of the gear, wherein one of the plurality of gears is formed such that the internal gear and the external gear can rotate together or rotate independently.

Patent JPH10159866 discloses a gear-shaped engagement member is provided on one of the inner peripheral surfaces of an outer ring and on one of the outer peripheral surfaces of an inner ring which is relatively rotatably disposed on an inner peripheral side of the outer ring. A torque limiter comprising: an assembly part and a spring member elastically engaged with the engagement part.

Disadvantages of the prior art

Prior art solutions often involve assembling multiple parts of complex configurations.

They concern an intermediate element of a gear train, with toothed wheels upstream and downstream. The aim is mainly to protect the electric motor, rather than to protect the entire drive chain against untimely actions exerted on the driven component.

The interacting parts involve significant deformations in the area near the trigger torque. These solutions are also not compact and lead to an increased size of the geared motor compared to a solution providing equivalent performance in terms of torque and output speed.

Patent US2020018358 mentions arc-shaped protrusions, which do not allow for maximizing the torque to be transmitted. This is a friction transmission, rather than an obstacle transmission. In reality, this document aims to protect the engine when the driven load is excessive, but not to protect the entire transmission chain in the event of an unexpected action on the driven component.

Finally, the known solutions do not allow for simple modifications to know the position of the driven organ at any time, even in the event of breakage of an element internal to the reducer.

Solution provided by the invention

The present invention relates, in its most general sense, to a geared motor having the characteristics set out in claim 1.

• L’une desdites couronne dentée ou pièce de liaison présente une surface tubulaire alternant
  • des segments lisses de rayon s’étendant chacun sur un angle de degrés et
  • des butées de transmission de couple de rayon s’étendant chacune sur un angle de degrés dont les points de rebroussement sont écartés d’un angle valant degrés
  • avec
• L’autre desdites couronne dentée ou pièce de liaison présentant des excroissances radiales, chacune porté par une zone déformable élastiquement radialement, pouvant se déplacer entre un rayon au repos et un rayon lorsque le couple appliqué entre ladite couronne dentée et ladite pièce de liaison dépasse une valeur de référence C_max.

The geared motor advantageously has an output toothed wheel provided with a toothed crown, constituting the last meshing stage of the movement reducer of said geared motor, associated with an elastically deformable connecting part characterized in that:

• One of said toothed crown or connecting piece has a tubular surface alternating
  • smooth segments of radius each extending over an angle of degrees and
  • radius torque transmission stops each extending over an angle of degrees whose cusps are spaced apart by an angle equal to degrees
  • with
• The other of said toothed crown or connecting piece having radial protrusions, each carried by a radially elastically deformable zone, capable of moving between a radius at rest and a ray when the torque applied between said toothed crown and said connecting part exceeds a reference value C _max .

• le nombre butées de transmission de couple de ladite couronne dentée est un multiple entier du nombre d’excroissances radiales de ladite pièce de liaison,
• ladite pièce de liaison présente une forme tubulaire prolongée radialement par des bras radiaux avec un pas de degrés, deux bras radiaux successifs étant reliés à leur extrémité radiale par lesdites zones déformables élastiquement,
• lesdites zones déformables élastiquement sont symétriques par rapport à au moins un plan radial,
• ladite couronne dentée présente butées de transmission de couple, avec compris entre 3 et 10, et de préférence égal à 5,
• des lames ressort sont disposées tangentiellement, chacune faisant face à une excroissance radiale, lesdites excroissances radiales étant prolongées radialement en direction de la lame ressort lui faisant face, jusqu’à son contact, par une zone d’appui,
• ladite pièce de liaison est formée par un manchon d’accouplement tubulaire présentant des bras rigides radiaux, et une couronne extérieure formée par des poutres déformables s’étendant chacune tangentiellement entre les extrémités de deux bras rigides consécutifs,
• le rayon est supérieur au rayon et lesdites zones déformables élastiquement sont constituées par des lames ressort s’étendant tangentiellement par rapport à un bras radial, les extrémités desdites lames ressort présentant des excroissances radiales s’étendant sur un arc de degrés, en particulier, l’écart angulaire entre les déformations de deux lames ressort consécutives peut être un multiple de ,
• ladite pièce de liaison est solidaire d’un aimant et ledit motoréducteur comporte une sonde magnéto-sensible positionnée dans une partie balayée par ledit aimant lors de la rotation de ladite pièce de liaison,
• un moyen de détection des variations de position relative de la roue dentée par rapport à la pièce de liaison, fournies par au moins un capteur, dans ce cas, un microcontrôleur peut exécuter un algorithme de comparaison des variations de position relative de ladite pièce de liaison par rapport à des variations de position relative dudit rotor, pour déterminer une perte de synchronisme entre ladite pièce de liaison et ladite couronne dentée, en outre, ledit microcontrôleur peut retourner à l’ECU du véhicule un message d’erreur lorsque ledit algorithme détermine une perte de synchronisme entre ladite pièce de liaison et ladite couronne dentée ; également ledit microcontrôleur peut posséder une séquence de réengagement consistant à commander un mouvement du rotor engendrant un mouvement de la couronne dentée, lorsque l’organe entrainé est en appui sur une butée, ladite séquence se terminant lorsque les butées de transmission de couple de la couronne dentée s’engagent avec les butées de transmission de couple de ladite pièce de liaison,
• dans le cas où une séquence de réengagement est intégrée, la détection de réengagement des butées de transmission de couple de la couronne dentée avec les excroissances radiales de ladite pièce de liaison peut être réalisée par
  • une comparaison des variations de position relative de ladite pièce de liaison par rapport à des variations de position relative dudit rotor, et/ou
  • par une mesure du courant consommé dudit motoréducteur, et/ou
  • par une mesure de l’angle de charge dudit motoréducteur,

en outre, ledit microcontrôleur peut retourner à l’ECU du véhicule un message lorsque ladite séquence de réengagement est terminée et que le système est opérationnel.The geared motor according to the invention may also include one or more compatible characteristics among the following:

• the number torque transmission stops of said toothed crown is an integer multiple of the number of radial protrusions of said connecting piece,
• said connecting piece has a tubular shape extended radially by radial arms with a pitch of degrees, two successive radial arms being connected at their radial end by said elastically deformable zones,
• said elastically deformable zones are symmetrical with respect to at least one radial plane,
• said toothed crown presents torque transmission stops, with between 3 and 10, and preferably equal to 5,
• spring blades are arranged tangentially, each facing a radial protrusion, said radial protrusions being extended radially in the direction of the spring blade facing it, until it comes into contact, by a support zone,
• said connecting part is formed by a tubular coupling sleeve having radial rigid arms, and an outer crown formed by deformable beams each extending tangentially between the ends of two consecutive rigid arms,
• the ray is greater than the radius and said elastically deformable zones are constituted by spring blades extending tangentially relative to a radial arm, the ends of said spring blades having radial protrusions extending over an arc of degrees, in particular, the angular difference between the deformations of two consecutive spring blades can be a multiple of ,
• said connecting piece is secured to a magnet and said geared motor comprises a magneto-sensitive probe positioned in a part swept by said magnet during rotation of said connecting piece,
• a means for detecting variations in the relative position of the toothed wheel with respect to the connecting piece, provided by at least one sensor, in this case, a microcontroller can execute an algorithm for comparing variations in the relative position of said connecting piece with variations in the relative position of said rotor, to determine a loss of synchronism between said connecting piece and said ring gear, in addition, said microcontroller can return to the vehicle's ECU an error message when said algorithm determines a loss of synchronism between said connecting piece and said ring gear; also said microcontroller can have a re-engagement sequence consisting of controlling a movement of the rotor generating a movement of the ring gear, when the driven member is resting on a stop, said sequence ending when the torque transmission stops of the ring gear engage with the torque transmission stops of said connecting piece,
• in the case where a re-engagement sequence is integrated, the detection of re-engagement of the torque transmission stops of the toothed crown with the radial protrusions of said connecting part can be carried out by
  • a comparison of the variations in relative position of said connecting piece with respect to variations in relative position of said rotor, and/or
  • by measuring the current consumed by said geared motor, and/or
  • by measuring the load angle of said geared motor,

further, said microcontroller can return to the vehicle ECU a message when said re-engagement sequence is completed and the system is operational.

According to another variant, said elastically deformable zones (274) are symmetrical with respect to at least one radial plane.

Advantageously, said toothed crown (260) has torque transmission stops (265), with between 3 and 10, and preferably equal to 5.

According to alternative embodiments, the geared motor which is the subject of the invention comprises:

- spring blades (277) arranged tangentially and each facing a radial protrusion (275), said radial protrusions (275) being extended radially in the direction of the spring blade (277) facing it, until it comes into contact, by a support zone (281)

- said connecting piece (270) is formed by a tubular coupling sleeve having radial rigid arms, and an outer crown formed by deformable beams each extending tangentially between the ends of two consecutive rigid arms.

- the ray is greater than the radius and in that said elastically deformable zones (274) are constituted by spring blades (277) integral with the connecting piece (270), extending tangentially with respect to a radial arm (273), the ends of said spring blades (277) having radial protrusions (275) extending over an arc of degrees.

- the angular difference between the deformations of two consecutive spring blades (277) is a multiple of .w

- said connecting piece (270) is secured to a magnet (280) and in that said geared motor comprises a magneto-sensitive probe (320) positioned near the magnet (280).

- it comprises a means for detecting variations in the relative position of the toothed wheel (260) with respect to the connecting part (270), provided by at least one sensor.

- the geared motor is equipped with a microcontroller executing an algorithm for comparing variations in the relative position of said connecting piece (270) with variations in the relative position of said rotor (110), to determine a loss of synchronism between said connecting piece (270) and said toothed crown (260).

- the microcontroller returns an error message to the vehicle's ECU when said algorithm determines a loss of synchronism between said connecting part (270) and said toothed crown (260).

Detailed description of a non-limiting example of an embodiment

The present invention will be better understood upon reading the following description, concerning a non-limiting example of embodiment illustrated by the appended drawings where:

there represents a schematic view of a charging hatch equipped with a geared motor according to the invention,

there represents a schematic top view of a geared motor according to the invention,

there represents a perspective view of a geared motor according to the invention without its housing (500),

there represents the toothed wheel of a torque limiter according to a first embodiment,

there represents the connecting piece associated with the toothed wheel of the to form the torque limiter according to the first embodiment,

,

Figures 5a and 5b represent exploded perspective views, respectively from above and below according to a first embodiment,

there represents an axial view of the torque limiter according to the first embodiment when the parasitic force is less than the trigger value,

there represents an axial view of the same torque limiter when the parasitic force is greater than the trigger value

there represents an exploded view of a torque limiter according to a second embodiment variant,

there represents an axial view of the torque limiter according to the second embodiment,

there represents a perspective view of a torque limiter according to a third embodiment,

there represents a front view of a torque limiter according to the third variant of the blade,

there represents an exploded view of a torque limiter according to a fourth embodiment,

there represents a perspective view of a geared motor according to a second variant embodiment,

there represents a couple view of a geared motor according to the second embodiment variant,

there represents a flowchart of a procedure for re-engaging the torque limiter according to the invention.

General principle

The invention proposes to protect the mechanics and electronics of the actuator from over-torque by disengaging the output shaft of the actuator from the last stage of its gearing. This makes it possible to protect the mechanical components, such as the gear wheels, as well as the electronic components of the actuator.

This provides invulnerability to the active element against these abnormal situations. Note that a malfunction could also emanate from the actuator and the invention similarly protects the aggregates coupled to it. It is important that the elastically deformable connecting part acts directly on the last stage of the reduction motor, and not on an intermediate stage, in order to protect all of the gears.

The aim of the invention is particularly to protect the entire mechanical drive chain, including when the electric motor is stationary, and not just to protect the motor against overheating in the event of high load.

Furthermore, the invention aims to trigger the clutch from a precisely predefined force threshold, without introducing play and preserving the precision of the drive without introducing play between the driven member and the drive mechanism, and therefore without introducing a situation of relative friction in the drive of the driven member.

To this end, the invention provides for inserting inside the output gear wheel of the geared motor a torque limiting part, ensuring the guidance of the output wheel and coupled directly, without additional gearing, to the driven member. This torque limiting part makes it possible to transmit the nominal torque without slippage and without disturbance, by preventing the transmission to the reduction chain, and to the actuator, of unwanted and/or potentially destructive torques, exerted on the driven member.

This torque limiting part interacts with the inner tubular surface of the output gear by a combination of radial protrusions forming radially extending teeth, provided on the tubular surface of the limiting part or the gear, and notches provided conversely on the tubular surface of the gear or the limiting part. The profile of the teeth corresponds to the hollow profile of the notches to allow congruent engagement of the tooth in the notch. The teeth and/or notches extend radially with respect to radially deformable tubular zones.

Another important consideration is that the guidance of the output wheel (which integrates the last stage of the geared motor) is carried out by the torque limiting part. The output toothed crown is guided directly by the torque limiting part, the guidance of which is ensured by a hub guided by a bearing provided on the cover of the housing (500), or better by two bearings arranged on the cover and the bottom of the housing (500), to ensure robust guidance of the output wheel on which the driven member is directly coupled, thus ensuring optimal force recovery.

The combination of this robust guidance of the last stage of the geared motor to which the driven member is directly coupled, and the integration directly into this last output stage of the frictionless triggering means, makes it possible to obtain optimized integration, operational safety and suitability for this type of application.

There illustrates an example of the integration of a geared motor (10) according to the invention and arranged to move, between an open position and a closed position, the hatch (20) obscuring a space containing the charging socket (30) on board an electric vehicle. Such hatches (20) being projecting from the vehicle, are both accessible to the user, who can actuate them voluntarily or accidentally, but are also potentially subject to environmental mechanical constraints. It is therefore essential to propose an actuation architecture capable of overcoming any degradation linked to unintended use. It is thus proposed to make the mechanical link between the rotor of the geared motor and the hatch (20) disengageable.

The invention proposes to integrate this additional functionality within the geared motor (10) while avoiding increasing its size. This provides a particularly integrated solution capable of being integrated into existing systems lacking this functionality, without requiring modification of the mechanical connection between the output of the geared motor (10) and the hatch (20) of the vehicle.

The aim of the invention is to support the additional function, namely the clutch, by a compact part, having a size close to that of a usual output toothed wheel of a geared motor, and allowing the nominal torque to be transmitted without slipping and without disturbance, but preventing the transmission on the reduction chain, and on the actuator, of untimely torques exerted on the driven member, here the trapdoor (20).

Figures 2 to 5b relate to a first embodiment according to the invention, the showing a cross-sectional top view of the geared motor (10) with the cover removed, the showing a perspective view from below of the geared motor without its housing (500) and allowing a better appreciation of the reduction chain, figures 4a and 4b separately showing the two elements of the output wheel (250) of the geared motor allowing a disengageable coupling and finally figures 5a and 5b show exploded perspective views of the two elements of the output wheel respectively in top and bottom orientation.

As more visible in and 3, the geared motor (10) is in the form of a housing (500) integrating an electric motor (100), consisting of a stator (120) and a rotor (110) coupled to a reduction chain (200) whose output wheel (250), provided with the additional function, is more particularly described in and 4b. The housing (500) further integrates an electronic card (300) having the means for controlling the coils (121) of the stator (120) and connected to a connector (400) to ensure the supply of electrical power to this electronic card (300) and to provide a communication channel with the ECU of the vehicle, via a LIN protocol for example. In the example illustrated, the reduction chain is a straight train consisting of 4 stages. This straight train is provided with three stages of pinion/toothed wheel assemblies (210, 220, 230) each mounted in free rotation on an axis (211, 221, 231), themselves mounted fixed in the bottom of the housing (500) for one end and in the cover (510) for its other end. All of the axes (211, 221, 231) being distributed in the transverse plane of the housing (500), all being parallel to the axis (111) of the rotor (110) and to the shaft (251) of the output wheel (250).

• des segments lisses (264) de rayon s’étendant chacune sur un angle α et
• butées de transmission de couple (265), valant 5 dans l’exemple présenté, s’étendant chacune sur un angle β et entre ledit rayon et un rayon , avec .

As presented more particularly in figures 4a, 4b, 5a and 5b, and in order to ensure the disengagement function, the output wheel (250) comprises a peripheral part provided with teeth (268) in the form of a toothed crown (260), surrounding a connecting part (270) elastically deformable to form a torque limiter (240). The toothed crown (260) has a wall (261) closing one of its axial ends, this wall (261) being perforated by a disc light (262) concentric with the toothed crown (260), said disc light being capable of receiving a cylindrical protuberance (278) of the connecting part (270) to ensure its rotational guidance. Said toothed crown (260) also has a tubular surface (263) alternating:

• smooth segments (264) of radius each extending over an angle α and
• torque transmission stops (265), worth 5 in the example presented, each extending over an angle β and between said radius and a ray , with .

THE torque transmission stops (265) are all identical and regularly distributed around the periphery of the tubular surface (263) at an angle , so that . In the example presented, each of said torque transmission stops (265) has a turning point (266) adjoining the radius .

The connecting piece (270) also has a cylindrical geometry, it is provided with a tubular shape (271) connected to a hub (272) by rigid radial arms (273). The hub (272) extends axially on either side of the tubular shape (271) in the form of cylindrical protuberances (278, 279). These cylindrical protuberances (278, 279) each cooperate with a guide means (510, 610) respectively located in the bottom of the housing (500) and in its cover (600), to ensure the rotational guidance of the output wheel (250). The cylindrical protuberances (278, 279) also have a coupling means (276) with the member to be driven. illustrates the coupling means in the form of a cavity with a star pattern, but this form is in no way limiting of the invention and any means known to those skilled in the art for transmitting torque is envisaged. For example the shows that this coupling means can have indexing by a flat so that only one orientation of the coupling means relative to the application is possible.

In is also presented, but without being limited to this exemplary embodiment, the insertion of the cylindrical protuberances (278, 279) each cooperating with a guide means (510, 610) respectively located in the bottom of the housing (500) and in its cover (600). In this case, these guide means are smooth bearings produced by tubular protrusions emerging in the direction of the barrels. Said tubular protrusions may be of a diameter greater than that of the cylindrical protuberances (278, 279) so as to accommodate them and guide them in contact with their interior surface, or could be of a smaller diameter, the cylindrical protuberances being able to fit onto them. In order to ensure axial stopping of the output wheel (250), the guide means (610) of the cover (600) may be provided with a wall (620) providing a bearing surface for the axial end of the cylindrical protuberance (278). In the case where the hub has a through passage for coupling with the member to be driven, the axial abutment of the output wheel (250) may be achieved by means of the axial end (625) of the guide means (610), which is then tubular in shape, providing a bearing surface for the disc wall (261) of the toothed wheel (260). Finally, when the guide means (510) is open, a cylindrical receiving zone (550) can be provided for the insertion of a seal (700), for example a toric lip seal, ensuring the sealing of the housing between the end (299) of the cylindrical protuberance (278) and the housing (500).

The assembly of the output wheel is therefore carried out by axial insertion of the connecting piece (270) into the toothed crown (260), the protuberance (278) penetrating the disc lumen (262) until the rigid radial arms (273) of the connecting piece (270) are axially abutted against the wall (261) of the toothed crown (260), thus forming a support-plane connection. The radial protrusions (275) and the tubular surface (263) provide short centering, through contacts preferably in the form of axial lines, regardless of the angular position between said toothed crown (260) and said connecting piece (270).

The output wheel (250) thus formed is driven by the reduction chain through the teeth of the crown gear (260) and drives the member to be moved by means of the coupling means (276) of the connecting piece (270). In order to ensure the transmission of torque between the crown gear (260) and the connecting piece (270), said connecting piece is an integral part, preferably made of plastic, obtained for example by a molding process. Said connecting piece (270) is provided with several radial protrusions (275) capable of engaging in the torque transmission stops (265) of the crown gear (260). The radial protrusions (275) are located in the middle of elastically deformable zones (274) of the tubular shape (271), said zones being for example arranged between the dotted lines of Figure 5a. These deformable zones are judiciously anchored at their ends to one of the rigid radial arms (273). The radial protrusions (275) are, like the torque transmission stops (265), regularly distributed around the periphery of the tubular shape (271) so as to form an angle between two successive radial outgrowths, with , being a natural integer greater than 0, worth 1 for the first embodiment.

Due to the elasticity of the elastically deformable zones (274), the radial ends of the radial protrusions (275) can move between a radius , in their rest position where they are engaged in the torque transmission stops (265), towards a radius when the torque applied between said toothed crown (260) and said connecting piece (270) exceeds a reference value C _max , allowing the angular sliding of said radial protrusions against the tubular surface (263) of the toothed crown (260).

Figures 6a and 6b illustrate axial views of the output wheel, respectively when the connecting piece (270) is in the rest state, with the radial protrusions (275) engaged in the torque transmission stops (265), or in the deformed state, with the radial protrusions (275) displaced towards the spoke. and allowing sliding on the tubular surface (263) of the toothed crown (260).

Non-limiting variants of the torque limiting part

Figures 7a, 7b, 8a, 8b, and 9 show alternative embodiments of the torque limiter (240) and more particularly of the coupling between the toothed crown (260) and the connecting piece (270).

The embodiment shown in Figure 7a and 7b differs from the previous embodiment, for example shown in Figure 5a, in that the radial protrusions (275) are not an integral part of the connecting piece (270), but are produced by a curvature of the ends of spring blades (277), these spring blades (277), preferably in the form of a metal strip, are secured in their middle to the radial ends of the rigid radial arms (273). In the example shown in Figure 7, the connecting piece has two rigid radial arms (273), two spring blades (277) each having two radial protrusions (275). This embodiment also differs from the previous embodiment in that the 4 radial protrusions (275) are not equally distributed along the angular periphery of the connecting piece. Indeed, regular distribution is not necessary for the invention, it is simply desired that all of the radial protrusions (275) each cooperate simultaneously with a torque transmission stop (265) of the toothed wheel (260), so as to optimize the breakaway torque C _max . It is thus more profitable, when using spring blades (277) and to aim for relatively low breakaway torques C _max , to move the radial protrusions (275) as far away as possible from the anchoring point in the rigid radial arms (273) and therefore to maximize the length of the spring blades (277). However, in order to maximize the number of possible indexing positions, the torque transmission stops (265) are, as for the previous embodiment, regularly distributed on the periphery of the tubular surface (263) while respecting the relationship . We therefore obtain two angular relationships, that between two radial outgrowths constituting the ends of the same spring blade (277), namely with worth 5 in the example of figure 7, and that between two neighboring protrusions belonging to two different spring blades, namely , worth 1 in the example of figure 5. Of course, the person skilled in the art could imagine other pairs and possibly generate a regular distribution with if for example the necessary length of the spring blades (277) lends itself to it. This embodiment is also not limited to two rigid bars and the person skilled in the art could easily modulate their number and arrangement without necessarily attaching rules of symmetry to them. This embodiment ensures a release torque C _max generated by means of spring blades (277) rather than using deformable plastic zones as shown in the first embodiment. This is particularly advantageous for obtaining greater release torques, but also for providing better behavior of the clutch function in the face of aging, exposure to high temperatures, and wear of the actuator.

A second alternative embodiment of the torque limiter (240) is presented in Figure 8, the latter differs from the first embodiment, presented for example in Figure 5, in that a spring blade (277) is housed in the angular space (282) located between two consecutive rigid radial arms (273) and delimited radially by the hub (272) on the one hand and by the elastically deformable zones (274), connecting the radial protrusions (275) to the rigid radial arms (273), on the other hand. Each spring blade (277) bears on its face opposite the hub (272) and by each of its tangential ends, on transverse flares (283) belonging to the rigid radial arms (273). A third support, on its opposite face and equidistant from the tangential ends, is obtained by cooperation with a support zone (281) extending from the radial protrusions (275) in the direction of the hub (272). The support zones (281) are provided, at their axial ends, with extensions extending radially beyond the spring blade so as to ensure its retention in the angular space (282). When an over-torque is applied, the radial protrusions (275) will join a radius by deforming both the elastically deformable zones (274) made of plastic but also the spring blades (277) via the support zones (281). This embodiment can be seen as a variant combining radial protrusions (275) made of plastic, as presented in the first embodiment, with metal spring blades (277) presented in the second embodiment. It can indeed be advantageous to ensure a long service life for the actuator thanks to the use of metal springs, while maintaining a plastic/plastic contact between the connecting part (270) and the toothed crown (260), so as to minimize the noise emitted by the disengagement and also the wear of the internal wall of the toothed crown (250).

A third alternative embodiment of the torque limiter (240) is presented in , the latter differs from the first embodiment, presented for example in figure 5, in that the deformable elements are not supported by the connecting piece (270) but by the toothed crown (260). This toothed crown (260) thus has rigid radial arms (273) extending towards the connecting piece (270) and are linked two by two by the elastically deformable zones (274) to form the tubular surface (263). The radial protrusions (275) are located in the elastically deformable zones (274) and extend towards the connecting piece (270). The torque transmission stops (265), in which the radial protrusions (275) engage, are directly integrated into the hub (272) of the connecting piece (270).

In all of the examples illustrated, the radial protrusions (275) are an integral part of the elastically deformable zones (274), whether the latter are supported by the toothed crown (260) or by the connecting piece (270). However, this is for illustration purposes and the person skilled in the art could easily envisage configurations where the torque transmission stops are housings located in the elastically deformable zones and where the radial protrusions (275) project from a rigid part. The important thing to achieve the desired disengagement is that the toothed crown (260) and the connecting piece (270) have conjugate coupling means and that the coupling means of at least one of the two pieces can move radially from a certain torque to allow the relative rotational movement of the tubular crown (260) relative to the connecting piece (270).

Note that the figures systematically show a connecting piece (270) inserted inside the toothed crown (260), which is in no way limiting of the invention and the person skilled in the art could easily imagine that the toothed crown (260) could be integrated within the connecting piece (270), in particular when the reduction of movement is done by means of an epicyclic type reducer. Also, the different figures illustrate a coupling for which the elastically deformable element (274) is integral with the connecting piece (270) and the torque transmission stops (265) integral with the toothed wheel (260), however the person skilled in the art could imagine the opposite situation. These two examples also illustrate the possibility, not shown, that the radius locating the radial position of the radial protrusions (275) in the deformed state allowing sliding on the tubular surface (263) of the toothed crown (260), i.e. greater than the radius locating the radial position of the radial outgrowths (275) in the resting state.

Detection of the actual position of the driven organ

• Le jeu dans les trains d’engrenage qui peut atteindre plusieurs degrés angulaires,
• le déclenchement du limiteur de couple,
• l’interruption de l’alimentation du motoréducteur,
• les glissements dans le limiteur de couple.

The invention also relates to the detection of the actual position of the driven member. This position cannot be deduced by simply reading the information provided by a sensor integrated in the geared motor. Indeed, different circumstances can introduce biases such as:

• The play in the gear trains which can reach several angular degrees,
• the triggering of the torque limiter,
• interruption of the power supply to the geared motor,
• slippage in the torque limiter.

One solution would be to provide a position sensor directly linked to the driven organ, which requires an additional component (end-of-travel sensor, etc.), wiring of this component, and positioning which is sometimes difficult in the operating context of the driven organ.

The invention consists of integrating the function of detecting the effective position of the driven member, by an absolute position sensor arranged downstream of the torque limiter, into the kinematic chain, which makes it possible to ensure that the position detected by this angular sensor is free from all the error factors mentioned above.

Figures 10a and 10b represent an exemplary embodiment of a torque limiter allowing the measurement of the absolute position. For this purpose, a tubular coding magnet (280) is secured to the connecting part (270) so as to move in direct connection with the output of the actuator which is mechanically linked to the member to be driven. The magnetic field of this coding magnet (280) is measured using a magneto-sensitive probe (320) arranged on a planar protrusion (310) of the electronic card (300) and opposite this coding magnet. The coding magnet (280) may for example have a rotating magnetization, according to the teachings of patent application WO2007099238A1, so as to provide an absolute position over one revolution.

The coding magnet (280) is inserted around the tubular shape (271) of the hub (272) until it is axially abutted against the rigid radial arms (273). Multiple lugs (285) extending radially from the tubular shape (271) beyond the inner diameter of the encoder magnet (280), are elastically deformed during insertion of the encoder magnet and allow the latter to be axially retained when it reaches its final axial position.

External activation of the movement of the driven organ

Another solution proposed by the invention concerns the activation of the movement of the driven member, by manual action on the latter when the geared motor is stopped. A movement propagates to the connecting part (270) secured to the encoder magnet (280). The movement of the encoder magnet (280) can be captured by the magneto-sensitive probe (320) to produce an electrical signal processed by a detection circuit.

It is also conceivable that this operation is carried out in very low consumption mode, the magneto-sensitive probe being able to have a very low consumption mode and be associated with a microcontroller equipped with a wake-up function. Thus, during phases when the vehicle is not in operation, it is acceptable that low-consumption functions continue to be functional. The probe is therefore always powered by consuming a few microwatts and can, when detecting a movement, wake up the microcontroller, which is more energy-hungry, to trigger the movement sequence of the organ driven by the actuator.

This movement sequence can, for example, be the opening or closing of a motorized hatch when the user presses on this hatch.

This provides a function that consumes very little energy on average, but which may occasionally require a greater quantity of resources.

Torque limiter trigger detection

The invention provides a procedure for detecting the triggering of the torque limiter. This procedure is based on measuring the variations in position of the connecting part (270) relative to that of the toothed crown (260). If these two relative positions do not change synchronously and proportionally, then the dedicated algorithm in the microcontroller can conclude that there is a loss of synchronism between these two elements, and therefore that the torque limiter is triggered. The variations in relative position between the toothed crown (260) with respect to the connecting piece (270) can be obtained using the addition of a second absolute position sensor on the toothed wheel (260) and by comparing the signals supplied by the two sensors, but it is also possible to obtain the position of the toothed wheel (260) using the position information of the rotor (110), obtained using the switching probes of the electrical phase supply, and by knowing the kinematic reduction ratio between the two toothed wheel (260) and the rotor (110).

Torque Limiter Re-Engagement Procedure

As presented in , the invention also provides a procedure for re-engaging the torque limiter. This procedure is based on information on the absolute position of the connecting part (270), as well as a direct or indirect measurement of the mechanical load applied to the actuator.

The procedure consists of bringing the driven member into a stop of the system (for example, into the closing stop), so as to lock its position, then forcing a movement at the rotor (110), so as to rotate the toothed wheel (260) until reaching the position where the torque transmission stops (265) of the toothed wheel (260) engage with the radial protrusions (275) of the connecting piece (270).

• Etape 1000 : L’actionneur opère un mouvement de mise en butée sur une des butées du système.
• Test 1001 : La mesure de la position absolue de l’organe est-elle celle d’une butée du système ?
  • Si non : tant que la durée de l’étape 1000 est inférieure à une durée prédéterminée (de l’ordre de la seconde), on poursuit l’étape 1000, si elle est supérieure à cette durée, alors l’actionneur rejoint l’étape 1010 au cours de laquelle l’actionneur arrête le mouvement de mise en butée et informe l’ECU du véhicule que le système de limitation de couple est en défaut.
  • Si oui : le programme rejoint l’étape 1002.
• Etape 1002 : L’actionneur opère le même mouvement de mise en butée que celui effectué en étape 1000.
• Test 1003 : La mesure de charge correspond-elle ou couple maximum nominal ?
  • Si non : tant que la durée de l’étape 1002 est inférieure à une durée prédéterminée (de l’ordre de la seconde), on poursuit l’étape 1002, si elle est supérieure à cette durée, alors l’actionneur rejoint l’étape 1020 au cours de laquelle l’actionneur arrête le mouvement de mise en butée et informe l’ECU du véhicule que le système de limitation de couple est en défaut.
  • Si oui : le programme rejoint l’étape 1004.
• Etape 1004 : L’actionneur arrête le mouvement de mise en butée et informe l’ECU du véhicule que le système de limitation de couple est réenclenché et que l’organe à entraîner est en position de butée.

The flowchart of the breaks down as follows:

• Step 1000: The actuator performs a stop movement on one of the system stops.
• Test 1001: Is the measurement of the absolute position of the organ that of a system stop?
  • If not: as long as the duration of step 1000 is less than a predetermined duration (of the order of a second), step 1000 is continued; if it is greater than this duration, then the actuator returns to step 1010 during which the actuator stops the stop movement and informs the vehicle's ECU that the torque limitation system is faulty.
  • If yes: the program goes to step 1002.
• Step 1002: The actuator performs the same stop movement as that performed in step 1000.
• Test 1003: Does the load measurement correspond to the nominal maximum torque?
  • If not: as long as the duration of step 1002 is less than a predetermined duration (of the order of a second), step 1002 is continued; if it is greater than this duration, then the actuator returns to step 1020 during which the actuator stops the stop movement and informs the vehicle's ECU that the torque limitation system is faulty.
  • If yes: the program goes to step 1004.
• Step 1004: The actuator stops the stop movement and informs the vehicle's ECU that the torque limiting system is re-engaged and that the component to be driven is in the stop position.

Claims (17)

Geared motor (10) having a housing (500), a cover (600), an output toothed wheel (250) provided with a toothed crown (260), constituting the last meshing stage of the movement reducer (200) of said geared motor, associated with a connecting piece (270) characterized in that:
-The connecting piece (270) is coupled directly to a driven member without additional gearing and in that
-One of said toothed crowns (260) or connecting piece (270) has a tubular surface (263) alternating

• smooth segments (264) of radius each extending over an angle of degrees and
• torque transmission stops (265) of radius each extending over an angle of degrees whose cusps (266) are spaced by an angle equal to degrees
• with

-The other of said toothed crown (260) or connecting piece (270) having radial protrusions (275), each carried by an elastically deformable zone (274) radially, capable of moving between a radius at rest and a ray when the torque applied between said toothed crown (260) and said connecting piece (270) exceeds a reference value C _max . Geared motor according to claim 1 characterized in that the guidance of said connecting piece (270) is ensured by at least one guide zone (510, 610) provided on the housing (500) of the geared motor or its cover (600). Geared motor according to claim 2 characterized in that the guide of said connecting part (270) has a hub (272) having at least one protuberance (278, 279) cooperating with a bearing (510, 610) provided on the housing (500) of the geared motor or the cover (600). Geared motor according to claim 1 characterized in that the guidance of the toothed crown (260) is ensured by the connecting piece (270). Geared motor according to the preceding claim, characterized in that the guidance of the toothed crown wheel (260) is ensured by the interaction with said radial protrusions (275). Geared motor according to claim 1 characterized in that one of said toothed crown (260) or connecting piece (270) has rigid radial arms (273) and the other of said toothed crown (260) or connecting piece (270) has a wall (261), providing a support-plane connection when said elements are in contact. Geared motor according to claim 1 characterized in that one of said toothed crown (260) or connecting piece (270) has a disc light (262) and the other of said toothed crown (260) or connecting piece (270) has a cylindrical protuberance (278), providing guidance by short centering. Geared motor according to claim 1 characterized in that the radial protrusions (275) and the tubular surface (263) provide short centering, through several contact zones distributed in radial formations, extending over the height of the tubular surface (263) in the form of axial lines, whatever the angular position between said toothed crown (260) and said connecting piece (270). Geared motor according to claim 1 characterized in that the number torque transmission stops (265) of said toothed crown (260) is an integer multiple of the number of radial protrusions (275) of said connecting piece (270). Geared motor according to claim 1 characterized in that said connecting piece (270) has a tubular shape (271) extended radially by radial arms (273) with a pitch of degrees, two successive radial arms being connected at their radial end by said elastically deformable zones (274). Geared motor according to claim 1 characterized in that the torque transmission stops (265) and the radial protrusions (275) have complementary shapes. Geared motor according to claim 1 characterized in that the torque transmission stops (265) and the radial protrusions (275) have a V shape, the angle of the V being between 80° and 110°. Geared motor according to the preceding claim, characterized in that said microcontroller has a re-engagement sequence consisting of controlling a movement of the rotor (110) generating a movement of the toothed crown (260), when the driven member is resting on a stop, said sequence ending when the torque transmission stops (265) of the toothed crown (260) engage with the torque transmission stops (275) of said connecting piece (270). Geared motor according to the preceding claim, characterized in that the detection of re-engagement of the torque transmission stops (265) of the toothed crown (260) with the radial protrusions (275) of said connecting piece (270) is carried out by

• a comparison of the variations in relative position of said connecting piece (270) with respect to variations in relative position of said rotor (110), and/or
• by measuring the current consumed by said geared motor, and/or
• by measuring the load angle of said geared motor.

Geared motor according to the preceding claim, characterized in that said microcontroller returns a message to the vehicle's ECU when said re-engagement sequence is complete and the system is operational. Geared motor according to one of the preceding claims, characterized in that the coupling means (276) of said connecting piece (270) incorporates a singularity making it possible to angularly index the axis of the driven member. Geared motor according to one of the preceding claims, characterized in that said microcontroller of the geared motor is provided with an algorithm generating an opening or closing movement sequence, triggered by a detection of variation in the position of said connecting part (270) in reaction to a movement of the driven member generated by an external force.