Actuator for a vehicle transmission parking lock system

Abstract

The present invention relates to an actuator (1) for a parking lock system for a vehicle transmission. Said actuator (1) comprises a housing (10) with an intermediate frame (90), an electric motor (20), and a rotating torque output element (80) capable of rotating between a locked position and a released position. Said electric motor (20) is a brushless DC motor provided with stator windings, a rotor, and an output shaft (23) connected to the rotor and extending along an X-axis. The actuator (1) includes an electronic board (40) comprising a device for determining the position of the rotor of the electric motor (20). Said electronic board (40) is positioned within the housing (10) and held in position by the intermediate frame (90). (See Figure 1 for abbreviations.)

Description

Title of the invention: Actuator for a parking lock system of a vehicle transmission

[0001] The invention relates to an actuator for a parking lock system of a vehicle gearbox, in particular a motor vehicle equipped with an automatic gearbox, for example a hybrid vehicle. The invention also applies to a parking lock system of a reducer associated with an electric vehicle motor. The gearbox or reducer will more generally be called a transmission box. This locking system is better known by its English term "park-lock" or "parking lock".

[0002] Such an actuator allows the transmission box to be locked in parking by means of a lever engaging with a toothing of the transmission box.

[0003] An actuator of the same type is known from document US 2019136960 AA. In this document, the actuator comprises a traditional brushed electric motor. A disadvantage of this type of brushed electric motor is that the brushes tend to stick to the commutator when the motor is not used for a long period, which can cause degraded operation of the actuator.

[0004] A parking lock system of a vehicle transmission is only used for a very short time, so it is preferable to use a brushless electric motor to avoid the inconvenience mentioned above. One of the disadvantages of this type of brushless electric motor is that the angular position of the motor rotor must be determined very precisely to control it. Thus, the support of the device for determining the position of the rotor of the electric motor must be positioned and held very precisely in the actuator.

[0005] The present invention relates to an actuator for a parking lock system of a transmission box improving current solutions while allowing reliable measurement of the angular position of the rotor of the engine.

[0006] More particularly, the invention relates to an actuator for a parking lock system of a vehicle transmission box, said actuator comprises a housing with an intermediate frame, an electric motor and a rotary torque output element so as to be able to rotate between a locking position and a release position, said electric motor is a brushless direct current motor provided with stator coils, a rotor and an output shaft linked to the rotor and extending along an X axis. The actuator comprises an electronic card comprising a device for determining the position of the rotor of the electric motor, said electronic card is positioned in the housing and held in position by the middle manager.

[0007] This arrangement thus allows very precise positioning and holding of the electronic card in the actuator, which allows reliable reading of the angular position of the rotor of the electric motor.

[0008] According to the invention, the electronic card is positioned in the housing by means of two slides coming from the housing. The positioning of the card by slide makes it possible to block the card according to two translations.

[0009] According to the invention, the electronic card is in contact with a bottom wall of the housing, this bottom wall comprises a system for clamping the electronic card.

[0010] According to the invention, the clamping system comprises at least two supports in contact with one face of the electronic card and at least one groove in contact with the opposite face of the electronic card. The combination of two supports and one groove makes it possible to temporarily clamp the electronic card in the housing during the operations of assembling the actuator and in particular the mounting of the electric motor.

[0011] According to a feature of the invention, the bottom wall comprises a protrusion opposite a groove in the electronic card in order to allow better retention of the electronic card in the housing.

[0012] According to an additional characteristic of the invention, the electronic card is held in position by the intermediate frame by a clamping system. More precisely, the clamping system comprises a deformable clip.

[0013] According to the invention, the electronic card extends in a plane substantially perpendicular to the X axis.

[0014] Advantageously, at least one multi-pole magnet is fixed to the output shaft of the electric motor and the device for determining the position of the rotor of the electric motor of the electronic card comprises at least one phase sensor located opposite the multi-pole magnet in order to ensure the electronic switching of the power supply to the stator coils of the electric motor.

[0015] According to the invention, the electronic card comprises power supply pins in order to electrically supply the stator coils of the electric motor.

[0016] According to another characteristic of the invention, the electronic card comprises an opening through which the output shaft of the electric motor passes.

[0017] Other characteristics and advantages of the invention will emerge from the following reading of a detailed example embodiment, with reference to the appended figures:

[0018] [Fig.l] represents a perspective view of the actuator according to the invention without the housing closing cover;

[0019] [Fig.2] represents a top view of the actuator according to the invention without the housing closing cover or intermediate frame;

[0020] [Fig.3] represents a sectional view AA of the actuator of [Fig.l];

[0021] [Fig.4] represents a sectional view BB of the actuator of [Fig.3];

[0022] [Fig.5] represents a more precise view of zone V of [Fig.l];

[0023] [Fig.6] represents a sectional view CC of the actuator of [Fig.5].

[0024] It should be noted that the figures disclose the invention in a manner sufficiently detailed for its implementation, said figures helping to better define the invention if necessary. The invention should not, however, be limited to the embodiment disclosed in the description.

[0025] With reference to [Fig.l] there is shown an actuator 1 of a parking locking system of a transmission box according to the invention. More precisely, this actuator 1 comprises a single-piece housing 10 composed of a first volume and a second volume.

[0026] In the first tubular-shaped volume there is an electric motor 20 of the brushless direct current type. This electric motor 20 comprises an output shaft 23. In the second parallelepiped-shaped volume there is mainly a reduction mechanism 70 in kinematic connection with the electric motor 20 and at least one electronic card 40. The first volume is closed by means of a first cover 12 and the second volume is closed by means of a second cover (not shown). The first cover 12 is fixed to the housing 10 by means of metal clips 13. The second cover 14 is fixed to the housing 10 by conventional closing means. A sealing means is provided between the cover 14 and the housing 10 and between the cover 12 and the housing 10.

[0027] The reduction mechanism 70 comprises a worm screw 22 positioned on the output shaft 23 of the electric motor 20 and meshes with a toothed wheel 30 on which the torque output element 80 is located. This torque output element 80 is produced in the form of a shaft concentric with the toothed wheel 30, the end of which has the form of a star-shaped female socket into which an actuating rod (not shown) of a locking system is capable of coming so as to lock or unlock a toothing of the transmission box (not shown) via an actuating lever (not shown). Alternatively, the torque output element 80 can be produced in the form of a male socket. This torque output element 80 is guided in rotation by a barrel of the housing 10 and an intermediate frame 90 fixed to the housing 10.

[0028] The housing 10 also comprises an electrical connector 15 for electrically connecting the internal components to the actuator 1.

[0029] Fastening means 11 in the form of metal inserts are arranged at several locations on the housing 10 in order to be able to fix it to the transmission box of the vehicle. In the present case, three inserts 11 are provided.

[0030] In [Fig.2], an X, Y, Z reference frame is illustrated. The X direction or axis corresponds to a longitudinal direction. The Y direction or axis, transverse, is defined as being perpendicular to the longitudinal direction X. More specifically, the longitudinal and transverse directions X, Y may, for example, substantially belong to a substantially horizontal plane. The direction or axis Z corresponds to a vertical direction. More specifically, the transverse and vertical directions Y, Z may, for example, substantially belong to a substantially vertical plane.

[0031] This [Fig.2] shows more precisely the integration of the electronic card 40, the electric motor 20 and the reduction mechanism 70 in the housing 10.

[0032] A multi-pole magnet 21 is fixed on the output shaft 23 of the electric motor 20. The magnet 21 is annular in shape and is coaxial with the output shaft 23. The magnet 21 has four poles. Of course, the magnet 21 can have a different number of poles.

[0033] The electronic card 40 comprises at least one device for determining the position of the rotor of the electric motor located opposite the multi-pole magnet 21 in order to provide a signal necessary for the electronic switching of the power supply to the stator coils of the electric motor 20.

[0034] The electronic card 40 extends in a plane substantially perpendicular to the X axis. The multi-pole magnet 21 extends in the same plane. The electronic card 40 comprises an opening 47 through which the output shaft 23 of the electric motor 20 passes. The multi-pole magnet 21 is also located in the opening 47.

[0035] The device for determining the position of the rotor of the electric motor 20 of the electronic card 40 comprises at least one phase sensor 41, 42, 43, located opposite the multi-pole magnet 21 in order to ensure the electronic switching of the power supply to the stator coils of the electric motor 20. More precisely, three sensors 41, 42, 43 are distributed on the electronic card 40 concentrically to the X axis. These three sensors 41, 42, 43 thus surround the multi-pole magnet 21. These three sensors are of the Hall effect type.

[0036] The electronic card 40 also comprises power supply pins 44, 45, 46, in order to electrically supply the stator coils of the electric motor 20. These pins 44, 45, 46 are three in number. These three pins 44, 45, 46 are distributed on the electronic card 40 concentrically to the X axis in an alternating manner with the three sensors 41, 42, 43.

[0037] This electronic card 40 is fixed to the housing 10 by means of slides 17 coming from the housing 10. In the present case, two slides 17 are necessary and distributed at the transverse ends of the second electronic card 40. The slides 17 seen from above have a “U” shape. The insertion in the Z direction of the electronic card 40 in the two slides 17 makes it possible to block the translation of the electronic card 40 along the X and Y axes.

[0038] When the electronic card 40 is completely inserted into the slides 17, it comes into contact with a bottom wall 100 of the housing 10 as can be seen in the [Fig. 3]. This bottom wall 100 comprises a system for clamping the electronic card 40. The clamping of the electronic card makes it possible to hold the electronic card 40 in the housing 10 when the latter is manipulated and pivoted for the assembly of the components of the actuator 1, in particular the assembly of the electric motor 20.

[0039] This clamping system is better visible in [Fig.4] and comprises at least two supports 110 in contact with one face of the electronic card 40 and at least one ridge 120 in contact with the opposite face of the electronic card 40. In other words, the supports 110 are located on one side of the electronic card 40 and the ridge is located on the other side of the electronic card 40. In the present case, three supports 110 are present and associated with three ridges 120.

[0040] The bottom wall 100 of the housing 10 comprises a protrusion 130 opposite a groove 131 of the electronic card 40. This protrusion makes it possible to block the translation of the electronic card 40 along the Y axis.

[0041] Another electronic card (not shown) allows the electronic management of the actuator and integrates electronic components necessary for the operation of the electric motor but also an angular position sensor of the torque output element 80. This other electronic card is supported by the intermediate frame 90. The two electronic cards are connected by a connector 60.

[0042] In addition to the fact that the intermediate frame 90 serves to guide the torque output element 80 in rotation and to support the other electronic card, the intermediate frame 90 also serves to hold the electronic card 40 in position in the housing 10.

[0043] [Fig. 5] shows the holding in position of the electronic card 40 in the housing 10 by the intermediate frame 90 with a clamping system. The clamping system comprises a deformable clip 91 which makes it possible to press the electronic card 40 against a face 92 of the intermediate frame 90, this face 92 being in the same plane Y, Z as the electronic card 40. According to the present invention, two deformable clips 91 offset along the Y axis are each associated with two faces 92 of the intermediate frame 90. The clips 91 and a part of the faces 92 are chamfered in order to facilitate the insertion of the intermediate frame 90, as visible in [Fig. 6]. Once the intermediate frame 90 is mounted in the housing 10, the electronic card 40 is blocked in translation along the Z axis.

[0044] The method of assembling the actuator is as follows: i) providing the housing 10; ii) inserting the electronic card 40 into the housing 10; iii) inserting the electric motor 20 into the housing 10; iv) inserting an intermediate frame 90 into the housing 10 in order to hold the electronic card.

[0045] Although the invention has been described in connection with a particular embodiment, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described.

[0046] In the claims, the reference symbols in parentheses should not be interpreted as a limitation of the claim.

Claims

Claims

1. Actuator (1) for a parking lock system of a vehicle transmission, said actuator (1) comprises a housing (10) with an intermediate frame (90), an electric motor (20) and a torque output element (80) rotatable so as to be able to rotate between a locking position and a release position, said electric motor (20) is brushless direct current provided with stator coils, a rotor and an output shaft (23) linked to the rotor and extending along an X axis, the actuator (1) comprises an electronic card (40) comprising a device for determining the position of the rotor of the electric motor (20), characterized in that said electronic card (40) is positioned in the housing (10) by means of two slides (17) coming from the housing (10) and held in position by the intermediate frame (90).

2. Actuator (1) according to claim 1, characterized in that the electronic card (40) is in contact with a bottom wall (100) of the housing (10), this bottom wall (100) comprises a clamping system (110, 120) of the electronic card (40).

3. Actuator (1) according to claim 2, characterized in that the clamping system comprises at least two supports (110) in contact with one face of the electronic card (40) and at least one groove (120) in contact with the opposite face of the electronic card (40).

4. Actuator (1) according to claim 2 or 3, characterized in that the bottom wall (100) comprises a protrusion (130) facing a groove (131) of the electronic card (40).

5. Actuator (1) according to one of the preceding claims, characterized in that the electronic card (40) is held in position by the intermediate frame (90) by a clamping system (91, 92).

6. Actuator (1) according to claim 5, characterized in that the pinching system comprises a deformable clip (91).

7. Actuator (1) according to one of the preceding claims, characterized in that the electronic card (40) extends in a plane substantially perpendicular to the X axis.

8. Actuator (1) according to one of the preceding claims, characterized in that at least one multi-pole magnet (21) is fixed on the output shaft (23) of the electric motor (20) and in that the device for determining the position of the rotor of the electric motor (20) of the card electronics (40) comprises at least one phase sensor (41, 42, 43) located opposite the multi-pole magnet (21) in order to ensure electronic switching of the power supply to the stator coils of the electric motor (20).

9. Actuator (1) according to one of the preceding claims, characterized in that the electronic card (40) comprises an opening (47) through which the output shaft (23) of the electric motor (20) passes.

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