JP7730893B2 - Actuators for automotive applications - Google Patents

Description

[0001] The present invention relates to an actuator for motor vehicle applications, in particular for a vehicle locking device, the actuator comprising an electric motor and at least one gear stage connected downstream of the electric motor and having a drive wheel and an output wheel, an actuating means operable by the gear stage, the gear stage having means for guiding gear components at least within a region.

[0002] Electrically operated actuators are increasingly being used in today's automobiles to improve the comfort of the automobile or to enable safe operation of the automobile. To improve comfort, for example, electrically adjustable exterior mirrors, seat adjustment devices or headlight adjustment devices should be mentioned, to name a few. Safety in operating the automobile can also be increased, for example, in that actuators are used to lock charging sockets or to improve the safety of the automobile, for example in the case of fuel filler flap locks.

[0003] In addition to these common applications for actuators, the latter are also used in connection with motor vehicle door closing devices, for example as closing drives or for locking motor vehicle locks. Furthermore, such actuators can be used to move so-called electrically operable lock retaining devices in order to close motor vehicle doors.

[0004] The available space in a motor vehicle is limited, in part because multiple functions can and should be performed in the vehicle. To meet this demand, high demands are placed on the gear stage of the actuator. In addition to a compact design, it must be possible to generate and transmit sometimes high forces through the gear stage.

[0005] Thus, within the scope of DE 10 2010 003 044 A1, a multi-stage gearing for adjusting a structural unit of a motor vehicle is described. The structural unit may be a seat adjuster, an exterior mirror adjuster, or a headlight adjuster, and in principle may also be a window lifter. The known multi-stage gearing operates with a first gear stage consisting of a worm and a spur gear or worm wheel meshing with the worm. A second gear stage is also implemented. The second gear stage consists of an evoloid pinion and an output wheel meshing with it. A spur or worm wheel engaging the worm is connected to the evoloid pinion. In this way, a compact gearing is provided that is also capable of transmitting high torques.

[0006] DE 102017125819 A1 also discloses an actuator for automotive applications, in which an electric motor acts on a drive train, which in turn moves an actuating element. An output wheel of a first gear stage and an evoroid pinion forming a spur gear stage are arranged in the drive train, preferably on the drive shaft of the electric motor.

[0007] In order to enable a large gear ratio and provide a compact actuator that is highly efficient and simultaneously reversible, unpublished DE 10 2020101 362.0 discloses an actuator with a crown gear stage. The crown gear stage allows for a high gear ratio at the same time as high efficiency. In particular, the crown gear stage ensures a compact design of the actuator.

[0008] High efficiency and compact design place high demands on the actuator structure. Here, especially when high forces are generated, gear stage components, which are mostly made of plastic, can be operated at least within their technical limits. For example, the limits of what is technically possible can be reached when very high forces must be generated by the actuator. For example, to close a side door, a force of 500 N may be required to move the door into the closed position. In this case, for example, a closing drive or an electrically operated locking device, a so-called servo locking device, is used.

[0009] DE 10 2014 005 656 A1 discloses a gear structure that ensures engagement of gear stages even within a limited range, allowing the gear stages to operate within the limited range. The publication aims to prevent skipping of gear elements, particularly toothed segments, that are engaged with each other, thus reducing wear and noise emissions of the gear elements. For this purpose, locking elements are provided that prevent the gear elements from drifting apart at limit positions.

[0010] The prior art presents solutions for compact, high-ratio safety gear stages for actuators in automotive applications. While applications have proven successful in principle, they reach their limits when there is not enough installation space available to ensure positive engagement of the gear elements. Herein lies the invention.

overview

[0011] The present invention is based on the technical problem of providing an actuator for automotive applications that ensures a maximum degree of safety in a gear stage during force transmission, compared to the prior art to date. It is therefore an object of the present invention to provide an improved actuator for automotive applications. In particular, it is an object of the present invention to provide an actuator that has a compact design and allows maximum safety in the transmission of large forces within a gear stage.

[0012] The object is achieved according to the invention by the features of independent claim 1. Advantageous embodiments of the invention are set out in the subclaims. It is pointed out that the exemplary embodiments described below are not limiting. Rather, any options for modification of the features described in the description and the dependent claims and drawings are possible.

[0013] According to claim 1, the object of the present invention is achieved by providing an actuator for motor vehicle applications, in particular for a vehicle locking device, comprising an electric motor, at least one gear stage connected downstream of the electric motor and having a drive wheel and an output wheel, and actuation means operable by said gear stage, the gear stage having means for guiding the gear components at least in a continuously guidable region. The inventive design of the actuator makes it possible to transmit large forces continuously through the gear stages with minimal structural means. In particular, the continuous guiding of the gear components ensures safety during operation at all times, even under varying loads. The continuous engagement of the guiding means during engagement of the gear components makes it possible to create a compact design which simultaneously ensures safe force transmission at all times.

[0014] The actuators related to the present invention are used in automotive applications. As explained in the introduction, they may be actuators for closing mechanisms, locks, seat adjustment devices, or locks for charging sockets in electric vehicles, to name a few exemplary technical applications. The actuators have actuation means, which in the case of a charging socket lock can be, for example, a locking pin that secures the plug and socket during the charging process. In this case, an extreme situation in the gear stage can occur, for example, when the plug is not inserted correctly, i.e., when the locking pin cannot move into its intended opening but, for example, moves relative to the plug housing. During the movement and impact of the plug housing, high loads are generated on the gear stage of the actuation means. The electric motor or its control device detects the current consumption, determines that the current consumption is increasing, and stops the electric motor. However, since the change in current consumption occurs with a certain delay, the electric motor cannot be stopped immediately when the stopping position is reached, but can only be stopped for a few milliseconds thereafter. During this time, very high forces act on the gear stage and can be absorbed by the continuous engagement of the guide means without causing the gear stage to skip over the toothed segments.

[0015] As the electric motor, a small DC motor is preferably used, which can apply high forces to the actuator through high rotational speeds and large gear ratios.

[0016] According to the present invention, it is preferred to use a crown gear stage that minimizes installation space. In particular, it is possible to arrange or form the central axis of the drive wheel perpendicular, preferably approximately perpendicular, to the central axis of the output wheel. As a result, it is possible to arrange the output wheel in a direction extending in the longitudinal direction of the drive wheel, thereby providing a gear stage that can be essentially limited by the width of the electric drive. Thus, compactness of the transmission device can be advantageously combined with a high transmission ratio and high efficiency.

[0017] An advantageous design variant of the present invention arises when the gear components have guiding means. According to the present invention, the gear components can be continuously guided. However, it has been found that there is an advantage in that further compactness can be achieved if the gears of the gear stage itself have guiding means. In particular, further structural guiding means can be omitted, as a result of which further structural freedom is possible. In this case, the gear components, i.e. the drive wheel and the output wheel, are engaged with each other in such a way that, on the one hand, force transmission is ensured and, on the other hand, the engaged gears are simultaneously guided. The gear stage therefore performs a double function: a drive function on the one hand and a guiding function on the other hand.

[0018] A further design variant of the present invention is achieved when the guiding means is provided by a form fit between the gear components, in particular the drive wheel and the output wheel. As a result of the form fit, the guiding means can be formed by the gear components themselves. In particular, the form fit provides a guiding means that ensures the axial distance and/or engagement conditions between the gear components during force transmission. This makes it possible to ensure that the engagement conditions do not change even if the tolerances change over the operating time of the actuator. The form fit between the gear components can be designed so that the axial distance is ensured on the one hand, and the engagement conditions are ensured on the other hand. The form fit provides a structurally simple means for achieving a compact design of the gear stage. Additional means for fixing the position can be omitted.

[0019] It has been found to be particularly advantageous to form the gear stage as a crown gear stage. By using a crown gear stage, a gear stage requiring minimal installation space can be provided. In particular, the central axis of the drive wheel can be formed perpendicular, preferably approximately perpendicular, to the central axis of the output wheel. As a result, it is possible to arrange the output wheel in the longitudinal extension of the drive wheel, thereby providing a gear stage that is substantially limited by the width of the electric drive. Thus, compactness of the gears can be advantageously combined with a high gear ratio and high efficiency. Furthermore, the crown gear stage offers the possibility of resetting, i.e., the crown gear stage can be manually reset. This offers the advantage that the actuating element can be manually reset in the event of a power supply failure.

[0020] A further design variant of the present invention is achieved when the drive wheel has an extension that can be guided in the output wheel. The drive wheel is preferably received in a form-fitting manner on the drive shaft of the electric motor and extends in the direction of the output wheel. If the gear stage is designed, for example, as a crown gear stage, a first portion of the drive wheel can have a toothing formed of one, two, three or more teeth. A subsequent second portion of the drive wheel forms an extension that serves as a guide means in the gear stage. This extension can be used as a means for guiding the output wheel. It has been found to be advantageous when the output wheel has a guide groove and the extension extends at least into the area within the guide groove. This structurally advantageous introduction of the extension into the guide groove provides a number of advantages. The first advantage is that the drive wheel can be formed as a single piece, facilitating its attachment to the drive shaft of the electric motor. The second advantage results from the fact that the guide groove can also be formed as a single piece on the output wheel. The third advantage results from the structural interaction between the extension and the guide groove, since the guide means can be integrated into the gear stage itself. This allows the number of components to be reduced to a minimum, and the advantage of functional reliability can be combined with structural advantages. As a result, a gear stage is provided that works independently of tolerances, or at least almost independently of tolerances, has a compact design, and offers high functional reliability.

[0021] A further advantageous design variant of the present invention is obtained when the actuator has a housing and the gear stage can be further guided by the housing. The guiding means can be provided by the gear stage itself. By engaging the housing itself with the gear stage, additional fixation and guidance of the gear stage components can be achieved. If an electric motor with a drive wheel and an output wheel is mounted or received in the housing, it can be further guided by the housing cover, further increasing functional reliability. On the one hand, the output wheel can be mounted, for example, by the housing cover, and on the other hand, the bearing point for the drive wheel can be provided by the housing cover.

[0022] In this case, it has proven to be particularly advantageous if the extension can be guided by the housing. If the drive wheel has a receiving area, a gear area and an extension, the extension can, on the one hand, serve as a guiding means that interacts with the output wheel. However, the extension can also be designed to protrude from the engagement area with the output wheel, providing a bearing point for the drive wheel. This structural engagement allows for the drive shaft to be further mounted, and in addition to being guided, also allows for the mounting of the drive wheel.

[0023] The actuator has at least two gear stages, at least one of which can be designed as a crown gear stage. Guiding the drive wheel to the output wheel allows the first gear stage to be used as a crown gear stage, thereby integrating the advantages of a crown gear stage into the actuator and ensuring high operational reliability. The second gear stage is preferably designed as an adjusting wheel stage, so that high gear ratios can be achieved on the one hand and established technology can be used on the other. The actuator or actuating means can then, for example, enable linear drive of the actuating means via a further gear stage. Overall, reliable introduction of forces to the gears of the actuator is thus guaranteed, and as a result of the structural design, the axial distance is guaranteed and tolerance-independent drive of the actuating means is made possible.

[0024] The present invention will be described in more detail below based on preferred embodiments with reference to the accompanying drawings. However, the principle that the exemplary embodiments do not limit the present invention but are merely advantageous embodiments is applied. The illustrated features can be implemented individually or in combination with further features of the specification as well as in the claims, individually or in combination.
[0025]
FIG. 1 shows a three-dimensional view of an actuator with linearly adjustable actuation means. FIG. 2 shows a view through the actuator of FIG. 1, with FIG. 2 showing the actuator with the housing cover.

Detailed Description of the Invention

1 shows a three-dimensional view of the actuator 1 in a three-dimensional view and in a view of the open housing 2. In this embodiment, the actuator 1 has a linearly adjustable actuation means 3. The actuation means can serve, for example, to lock a fuel filler flap or a charging plug. In this embodiment, the actuator 1 has a first gear stage as a crown gear stage 4, a second gear stage as a spur gear stage 5, and a third gear stage as a toothed rack stage 6. The crown gear stage 4 is mounted on a first shaft 7, and the spur gear stage 5 and the toothed rack stage 6 are mounted on a second shaft 8. The gear stages 4, 5, 6 are driven by an electric motor 9 and a drive shaft 10 of the electric motor 9. The electric motor 9 and the shafts 7, 8 are received on at least one side of the housing 2.

[0027] The crown gear stage 4 is formed by a drive wheel 11 and an output wheel 12. All gear components 4, 5, 6 are arranged in the interior 13 of the housing 2. The drive wheel 11 is received in a form-fitting manner on the drive shaft 10 of the electric motor 9. The drive wheel 11 is divided into functional areas. The drive wheel 11 has a receiving area 14, a gear area 15, and a guide area 16 in the form of an extension 16. The crown gear stage 4 further has a crown gear 17, a guide groove 18, and a spur gear 19. In this embodiment, the crown gear 17, the guide groove 18, and the spur gear 19 are formed integrally.

[0028] In this embodiment, the guide means 20 is formed from an extension 16 on the drive wheel 11, and the guide groove 18 is formed on the output wheel 12. The extension 16 engages form-fittingly with the groove 18 of the output wheel 12, so that a secure engagement and consequently a safe force transmission can be achieved in the crown gear stage. The structural design of the guide means 20 ensures high functional reliability of the actuator 1 with minimal structural effort and a minimum number of parts.

[0029] Drive shaft 10 is driven via electric motor 9 to transmit force or torque to crown gear stage 4. Crown gear 17 is integrally formed with spur gear 19 and is capable of transmitting torque to spur gear stage 5. Spur gear stage 5 is operatively connected to gear 21 of toothed rack stage 6, and actuating means 3 is movable from housing 2 into housing 2 by toothed rack stage 6. Actuating means 3 is shown movable via a seal. Additionally, a circumferential housing seal 23 interacts with housing cover 24 to seal housing 2.

2 shows the actuator 1 in the view according to FIG. 1, with the addition of a housing cover 24. It can be seen that the housing cover 24 provides bearing means 25, 26, and 27 for the actuator 1. The first bearing means 25 serves to securely and play-freely accommodate the electric motor 9 in the housing 2. The cylindrical extension 27 serves as a bearing means 27 for the shaft 7 of the crown gear 17 of the crown gear stage 4. It can also be seen that the bearing point 26 for the drive wheel 11 is provided by the housing cover 24. The bearing point 26 engages, at least in an area, with the extension 16 of the drive wheel 11. This allows the bearing point 26 for the drive wheel 1 to be provided by the bearing means 26, further increasing the functional reliability of the actuator 11. As a result of the inventive design of the actuator 1, a compact design of the actuator 1 can be ensured, high forces can be transmitted, and skipping of the interlocking toothed segments can be prevented even in extreme situations, particularly in the crown gear stage 4.

Explanation of symbols

1...actuator,
2...Housing,
3...operating means,
4... gear stage, crown gear stage,
5...spur gear stage,
6...toothed rack stage,
7, 8...axis,
9...electric motor,
10...drive shaft,
11... drive wheel,
12...output wheel,
13...inside of the housing,
14...receptive area,
15... Gear area,
16... Guide area, extension,
17...crown gear,
18...guide groove,
19...Spur gear,
20...guiding means,
21... gears,
22...Seal,
23...Housing seal,
24...Housing cover,
25, 26, 27...Bearing means.

Claims (10)

An actuator (1) for a motor vehicle, in particular for a locking device of a motor vehicle, comprising an electric motor (9), at least one gear stage (4, 5, 6) connected downstream of said electric motor (9) and having a drive wheel (11) and an output wheel (12), and actuation means (3),
the actuation means (3) are operable by the gear stages (4, 5, 6), the gear stages (4, 5, 6) having guiding means (20) for guiding the gear elements (11, 12) at least in the region thereof,
the guiding means (20) is formed from an extension (16) on the drive wheel (11), and a guide groove (18) is formed on the output wheel (12), and the extension (16) engages with the guide groove (18), thereby allowing the gear components (11, 12) to be continuously guided ;
The actuator (1) is characterized in that the housing (2) in which the drive wheel (11) and the output wheel (12) are arranged provides first, second and third bearing means (25, 26, 27), the first bearing means (25) fixing the electric motor (9), the second bearing means (26) engaging the extension (16) to provide a bearing point for the drive wheel (11), and the third bearing means (27) providing a bearing point for the output wheel (12) . An actuator (1) as described in claim 1, characterized in that the gear components (11, 12) have means for guiding (16, 18, 20). An actuator (1) as described in claim 2, characterized in that the guiding means (16, 18, 20) can be provided by a form fit between the drive wheel (11) and the output wheel (12). An actuator (1) according to any one of claims 1 to 3, characterized in that at least one gear stage (4, 5, 6) is a crown gear stage (4). An actuator (1) according to any one of claims 1 to 4, characterized in that there are at least two gear stages (4, 5, 6), and at least one gear stage (4, 5, 6) is a crown gear stage (4). The actuator (1) according to any one of claims 1 to 5, characterized in that the drive wheel (11) has the extension (16) and the extension (16) can be guided into the output wheel (12). An actuator (1) according to any one of claims 1 to 6, characterized in that the extension (16) is form-fitted at least in the guide groove (18). The actuator (1) according to any one of claims 1 to 7, characterized in that the actuator (1) has a housing (2) by means of which the gear stages (4, 5, 6) can be further guided. An actuator (1) according to any one of claims 1 to 8, characterized in that the extension (16) can be guided by the housing (2). Actuator (1) according to any one of claims 1 to 9, characterized in that the drive wheel (11) and/or the drive shaft of the electric motor (9) can be formed integrally.