Actuator for motor vehicle applications

Abstract

The invention relates to an actuator for motor vehicle applications, in particular for a motor vehicle lock and preferably an actuator integrated in a motor vehicle door lock. In its basic construction, the actuator has an electric motor (4) and an actuating element (10) which is acted upon directly or indirectly by the electric motor (4) via a drive train (5 to 9). The drive train (5 to 9) is equipped with at least one first evoloid toothing (5, 6) and one second evoloid toothing (7, 8) which adjoin one another. Each evoloid toothing (5, 6; 7, 8) has: an evoloid pinion (5, 7) which can be rotated about an evoloid axle (5a, 7a); and an evoloid output wheel (6, 8) which meshes with the evoloid pinion and can be rotated about a wheel axle (6a, 8a). According to the invention, the two evoloid toothings (5, 6; 7, 8) are positioned perpendicular to one another in such a way that the two evoloid axles (5a, 7a) are for the most part perpendicular to one another.

Description

[0001] Description

[0002] Actuator for automotive applications

[0003] The invention relates to an actuator for automotive applications, in particular a drive for a motor vehicle lock and preferably a drive integrated into a motor vehicle door lock, with an electric motor and with an actuating element acted upon directly or indirectly by the electric motor via a drive train, wherein the drive train is equipped with at least a first and a second evoloid toothing which are connected to one another, and wherein the respective evoloid toothing has an evoloid pinion which is rotatable about an evoloid axis and an evoloid output wheel which meshes therewith and which is rotatable about a wheel axis.

[0004] Actuators for automotive applications are used in a wide variety of ways on and in motor vehicles. For example, such actuators are used to adjust an exterior mirror, adjust a seat, adjust headlights, actuate window lifts, or even activate or adjust windshield wipers. Furthermore, such actuators can also be used to actuate flap elements such as a tailgate, trunk lid, vehicle door, hood, or similar.

[0005] In addition to these general automotive applications for actuators, they are particularly preferred and used in practice in conjunction with motor vehicle locking devices. Such motor vehicle locking devices usually involve motor vehicle locks and, in particular, motor vehicle door locks. In this context, the actuator or drive, for example, acts as an opening drive and ensures that a locking mechanism of the motor vehicle locking device is opened. To do this, the drive acts on a pawl, for example, and lifts this from its latching engagement with the rotary latch. Such drives are also often used as closing drives and ensure that the locking mechanism in question is closed. This usually occurs from a previously assumed pre-locking position into a main locking position or even an overtravel position.

[0006] Closing actuators are often designed separately from a vehicle locking device or lock and, for this purpose, are constructed as a spindle-to-spindle-nut drive, as described in the state of the art according to DE 202008 007 719 U1. However, the design effort in this context is considerable because, for example, both the actuator and the associated vehicle lock must have their own housing. Furthermore, a coupling and flexible connecting element, such as a Bowden cable, is required. Finally, there is often not enough space in a vehicle side door for both the actuator and the vehicle lock.

[0007] For this reason, actuators with a compact design are favored in practice, as installation space is often limited. This applies not only when the actuator in question is to be installed inside a vehicle door in conjunction with a vehicle lock, but also in applications for seat adjustment, an exterior mirror, or even headlight adjustment, as well as in conjunction with a window regulator.

[0008] Since some of the aforementioned applications require high actuation forces or high torques, multi-stage gearboxes are often implemented, which are actuated by a high-speed electric motor. This allows slow actuating movements with high torque to be achieved on the output side of the gearbox. This is possible even when the electric motor—as is common in automotive applications—is operated with a low DC voltage and moderate electrical currents, and thus with a relatively low electrical power.

[0009] For this purpose, the generic prior art according to DE 102017 125 819 A1 proposes an actuator equipped with an evoloid pinion on the output shaft of the electric motor, which also meshes with an evoloid output gear, directly forming a first evoloid toothing at the input of the drive train. In addition, the drive train then also has a second evoloid toothing.

[0010] Such evoloid gears are typically characterized by high transmission or reduction ratios, allowing high torque to be provided on the output side using a small number of gear stages. This means that high speed reduction ratios of, for example, more than 5 to 1 or even more than 10 to 1 can usually be achieved at this point, assuming the input-side, high-speed electric motor is used and considering that the actuator provided on the output side of the drive train, in contrast, requires only small actuating movements but still high torque.

[0011] The two evoloid gears in the generic state of the art according to DE 10 2017 125 819 A1 already ensure that a particularly compact design is achieved and, at the same time, high transmission or reduction ratios are made available using a single or at most two gear stages. The generally generic state of the art according to DE 10 2008 054 398 A1 shows comparable advantages. In contrast to the first-mentioned publication DE 10 2017 125 819 A1, which represents the closest prior art, the drive mentioned in second place (in DE 10 2008 054 398 A1) is predominantly used in connection with the actuation of a motor vehicle brake, so that in this context, the use of suitable materials depends in particular on being able to control any heat influence of the brake.For this reason, the individual gears – if at all – are made from special plastics, such as polyphthalamide (PPA) or aromatic polyamide (PA). However, such plastics are particularly cost-intensive and are therefore not used in actuators used in or in conjunction with motor vehicle locking devices, as these are produced in extremely high quantities.

[0012] The state of the art has proven itself overall, but still offers room for further improvements. Both the closest teachings according to DE 10 2017 125 819 A1 and DE 10 2008 054 398 A1 generally proceed in such a way that the two evoloid gears are connected to each other in such a way that the evoloid axis and the associated wheel axis run parallel to each other. While a somewhat nested arrangement is observed overall, the arrangement of the individual output gears, one behind the other, results in a relatively bulky structure. The invention aims to remedy this situation.

[0013] The invention is based on the technical problem of further developing such an actuator for automotive applications in such a way that a further improved use of space is observed compared to the prior art and consequently the compactness is improved.

[0014] To solve this technical problem, a generic actuator for automotive applications is characterized within the scope of the invention in that the two evoloid toothings are arranged perpendicular to each other, in such a way that the two evoloid axes are largely perpendicular to each other.

[0015] This means that within the scope of the invention, the two evoloid toothings continue to directly adjoin one another. However, the overall approach is such that, unlike the prior art, the two evoloid toothings do not correspond to engagement surfaces aligned parallel to one another. Instead, according to the invention, the respective engagement surfaces of the two evoloid toothings are arranged perpendicular to one another, allowing the installation space to be reduced to a greater or lesser extent compared to previous embodiments.

[0016] In fact, within the scope of the invention and advantageously, the two evoloid toothings or their engagement surfaces are arranged predominantly perpendicular to one another, in such a way that the evoloid axis and the wheel axis of one of the two evoloid toothings are arranged perpendicular to one another. This means that at least one of the two evoloid toothings is designed such that the evoloid axis of the evoloid pinion, on the one hand, and the wheel axis of the meshing evoloid driven gear, on the other hand, enclose a predominantly perpendicular angle between them, and are therefore arranged perpendicular to one another. This means that the evoloid driven gear can be placed “on” the evoloid pinion, as it were. This means thatThe evoloid driven gear extends from the evoloid axis of the evoloid pinion in a virtually vertical extension above or below the evoloid axis and connects to the evoloid pinion, so that the evoloid pinion and the evoloid driven gear can still come into contact with each other unchanged. For this purpose, the respective evoloid driven gear usually has helical gearing, whereas the associated evoloid pinion is equipped with evoloid gearing, as will be explained in more detail in the context of the exemplary embodiment. In most cases, the evoloid axis and the wheel axis of the first evoloid gearing are arranged largely perpendicular to each other. In contrast, the evoloid axis and the wheel axis of the second evoloid gearing are arranged predominantly parallel to each other.The relativization of the arrangements in the sense of “largely” or “predominantly” takes into account the fact that the corresponding gear wheels are mostly designed and assembled as plastic gears with limited manufacturing accuracy.

[0017] Since the two evoloid gears (directly) adjoin one another, the design is also such that the wheel axis of the first evoloid gear coincides with the evoloid axis of the second evoloid gear. This is achieved and ensured within the scope of the invention by equipping and connecting the evoloid driven gear of the first evoloid gear with an evoloid pinion, or by connecting this pinion to the evoloid driven gear in such a way that the wheel axis and the evoloid axis coincide. This allows the evoloid axis and the wheel axis of the second evoloid gear to be arranged predominantly parallel to one another.

[0018] Furthermore, the design is further such that the evoloid axis of the first evoloid toothing and a drive axis of an output shaft of the electric motor coincide. As a result, the output shaft of the electric motor accommodates the evoloid pinion of the first evoloid toothing. Since, moreover, the evoloid axis and the wheel axis of the first evoloid toothing are arranged perpendicular to one another, according to an advantageous embodiment, the overall structure is such that the evoloid output gear of the first evoloid toothing connects vertically above or below the output shaft of the electric motor as the evoloid axis of the first evoloid toothing with the evoloid pinion arranged thereon. The evoloid output gear of the second evoloid toothing is furthermore and advantageously equipped with an output pinion for driving a drive pawl as an actuating element.In this way, the two evoloid gears, in conjunction with the output pinion, define the drive train as a whole, which, in a preferred variant, directly acts on the actuating element or the drive pawl as the actuating element. This direct actuation results from the fact that the output pinion of the drive train generally meshes with the drive pawl via a toothed segment. This means that the drive pawl advantageously engages the output pinion with the corresponding toothed segment. In addition, the drive pawl usually also has a drive arm for actuating a locking mechanism consisting essentially of a rotary latch and a pawl.

[0019] In addition to the described direct actuation of the actuating element or the drive pawl by means of the drive train, it is of course also fundamentally possible and within the scope of the invention for the actuating element to be actuated indirectly. In this case, the output pinion at the end of the drive train may, for example, work on another pinion, which in turn then acts on the drive pawl. Of course, a different connecting means (other than the previously described gear) can also be interposed between the output pinion and the drive pawl, or generally the actuating element, in order to ensure indirect actuation of the actuating element by means of the drive train.

[0020] To achieve a design that is both cost-effective and durable, the output pinion and drive pawl are typically made of metal, such as steel. This allows for repeated adjustments over long timescales. In contrast, the evoloid pinions and evoloid output gears are usually at least partially constructed from plastic gears. In most cases, the evoloid pinions and evoloid output gears are all made of plastic gears. These can be manufactured particularly cost-effectively from materials such as thermoplastics, possibly with embedded glass or plastic fibers. Furthermore, such plastic gears are lightweight.

[0021] The invention also relates to a motor vehicle lock, and in particular a motor vehicle door lock, which is equipped with a locking mechanism consisting essentially of a rotary latch and a pawl. Furthermore, the motor vehicle lock, and in particular a motor vehicle door lock, in question further comprises an actuator for the locking mechanism. The actuator can act as an opening drive for the pawl by lifting the pawl from its latching engagement with the rotary latch. The rotary latch can then open with spring support. However, it is also possible for the actuator to act as a closing drive for the rotary latch. In this case, the closing drive ensures that the rotary latch, which has been manually moved into a pre-locking position, for example, is closed with the aid of the actuating element or the drive pawl in the example case, to the main locking position or even an overtravel position.In principle, the actuator can also work as an opening drive on the pawl or as a closing drive on the rotary latch.

[0022] In all of these cases, the actuator described above and according to the invention is integrated into the relevant motor vehicle lock, and in particular, the motor vehicle door lock. This additionally means that the actuator in question, together with the locking mechanism and any other lock components, is housed in a common lock housing, and in particular, the door lock housing, or generally a common housing. For weight and cost reasons, the housing in question is typically also made of plastic and is usually sealed against moisture and dust.

[0023] Thus, an actuator for automotive applications is described, which is particularly suitable for use with motor vehicle locking devices in general, and specifically with motor vehicle locks, and preferably with motor vehicle door locks. Indeed, in this context, the actuator in question can advantageously assume the function of an opening drive and / or closing drive. For this purpose, the drive in question is typically integrated into the housing of the motor vehicle locking device in general or of the motor vehicle lock, and preferably of the motor vehicle door lock.

[0024] All of this is possible and can be implemented because, on the one hand, a drive train with ultimately only two or three gear stages consisting of the two evoloid gears and the output pinion on the output side, which engages with the drive pawl as an actuating element, is used. Nevertheless, this and, on the other hand, allow for transmission or reduction ratios to be realized that can assume values ​​comparable to those in the generic state of the art according to DE 10 2017 125 819 A1, for example, values ​​of more than 50 to 1 and even more than 80 to 1 for the entire transmission. This makes high torques and forces available at the actuating element.

[0025] At the same time, the actuator according to the invention is characterized by a particularly compact design, which is essentially due to the fact that the two evoloid gears are arranged perpendicular to each other, i.e., their respective engagement surfaces are arranged perpendicular to each other, as described in detail above. This allows, in particular, the evoloid output gear of the first evoloid gear to be positioned in a virtually vertical projection above the corresponding evoloid pinion arranged on the output shaft of the electric motor.

[0026] In this way, no additional lateral installation space is required for the respective evoloid output gear, and the evoloid output gear of the second evoloid gearing can be positioned directly adjacent to the electric motor, as will be described in more detail below in the exemplary embodiment. In any case, these considerations make it clear that the invention results in an even smaller installation volume compared to the prior art, which, in conjunction with the high transmission or reduction ratio, the low weight, and, at the same time, the low cost, offers particular advantages.

[0027] The invention is explained in more detail below with reference to a drawing illustrating only one exemplary embodiment. The sole Figure 1 shows a perspective view of the actuator according to the invention for automotive applications.

[0028] Fig. 1 shows an actuator for automotive applications. In fact, the actuator in question is generally used as a drive in conjunction with a motor vehicle lock, and preferably a motor vehicle door lock. For this purpose, the actuator is integrated into a housing 1 of the motor vehicle lock in question, which is only indicated in Fig. 1. The housing 1 is made of plastic. It can be seen that the housing 1 not only accommodates the actuator, which will be described in more detail below, but also a locking mechanism 2, 3 consisting of a rotary latch 2 and a pawl 3 with conventional functionality. In this way, the actuator can operate, for example, as a closing drive on the rotary latch 2, which is not shown in detail, but functions in a manner comparable to the prior art according to DE 20 2008 007 719 U1.In contrast, a variant is shown in which the actuator acts as an opening drive and for this purpose lifts the pawl 3 from its locking engagement with the rotary latch 2, as indicated by corresponding arrows in Fig. 1.

[0029] The actuator, which is housed in the housing 1 together with the locking mechanism 2, 3, is fundamentally equipped with an electric motor 4 and a drive train 5, 6, 7, 8, 9. According to the exemplary embodiment, the drive train 5 to 9 operates directly on an actuating element 10, which, according to the exemplary embodiment, is designed as a drive pawl 10. With the aid of the drive pawl 10 and when the actuator is designed as an opening drive for the illustrated motor vehicle lock, the pawl 3 can be pivoted about its axis in the clockwise direction indicated in Fig. 1, so that the pawl 3 releases the previously trapped rotary latch 2 (in the illustrated closed position), which in turn pivots open under spring support and releases a locking bolt (not shown). The same applies to an associated motor vehicle door.

[0030] The drive train 5 to 9 is equipped in detail with at least two adjoining evoloid toothings 5, 6; 7, 8. In fact, a first evoloid toothing 5, 6 and a second evoloid toothing 7, 8 are realized. On the output side of the drive train 5 to 9, an output pinion 9 can be seen, with the aid of which the drive pawl 10 is actuated as an actuating element. For this purpose, the drive pawl 10 is equipped with a toothed segment 10a, which engages and meshes with the output pinion 9. In addition, the drive pawl 10 also has a drive arm 10b, with the aid of which the locking mechanism 2, 3 is actuated and, specifically and according to the exemplary embodiment, the pawl 3 is lifted from its locking engagement with the rotary latch 2 - as described.

[0031] The two evoloid toothings 5, 6; 7, 8 adjoin one another directly. Furthermore, each evoloid toothing 5, 6; 7, 8 has a respective evoloid pinion 5 or 7, which is rotatable about an associated evoloid axis 5a, 7a. A corresponding evoloid driven gear 6, 8, which is rotatable about an associated wheel axis 6a, 8a, meshes with the respective evoloid pinion 5, 7. It can be seen that the output pinion 9 provided on the output side of the drive train 5 to 9 is also equipped with an axis 9a, which, according to the exemplary embodiment, coincides with the wheel axis 8a of the evoloid driven gear 8 of the second evoloid toothing 7, 8.

[0032] According to the invention, the design is such that the two evoloid toothings 5, 6; 7, 8 are arranged perpendicular to one another. The perpendicular arrangement is achieved by the fact that the two evoloid toothings 5, 6; 7, 8 have an arrangement of their respective evoloid axes 5a; 7a, which run perpendicular to one another. In fact, the design within the scope of the exemplary embodiment is such that the evoloid axis 5a of the first evoloid toothing 5, 6 and a drive axis of an output shaft of the electric motor 4 coincide. In fact, the evoloid pinion 5 of the first evoloid toothing 5, 6 is arranged on the respective output shaft of the electric motor 4.

[0033] Furthermore, since the evoloid axis 5a of the evoloid pinion 5 and the wheel axis 6a of the evoloid driven gear 6 of the first evoloid toothing 5, 6 are arranged perpendicular to one another, the evoloid driven gear 6 can be arranged virtually "on" the evoloid pinion 5 in a vertical projection or vertical extension of the output shaft of the electric motor 4 and consequently of the evoloid axis 5a of the evoloid pinion 5 of the first evoloid toothing 5, 6. As a result, the evoloid driven gear 6 of the first evoloid toothing 5, 6 requires practically no lateral installation space and, when viewed from the front, at least partially covers the electric motor 4 with its cylindrical housing.

[0034] In contrast, the evoloid axis 7a and the wheel axis 8a of the second evoloid toothing 7, 8 are arranged parallel to each other. Furthermore, the design is such that the wheel axis 6a of the evoloid driven gear 6 of the first evoloid toothing 5, 6 coincides with the evoloid axis 7a of the evoloid pinion 7 of the second evoloid toothing 7, 8. This allows the evoloid driven gear 8, which meshes with the evoloid pinion 7, to be arranged directly adjacent to the electric motor 4. The evoloid driven gear 8 of the second evoloid toothing 7, 8 is now rotationally fixedly coupled to the output pinion 9. For this purpose, the respective evoloid driven gear 8, on the one hand, and the output pinion 9, on the other, have a common axis 8a, 9a.

[0035] The respective evoloid gearing 5, 6 and 6, 7 is each equipped with a helical evoloid gearing with a large gear ratio. Furthermore, according to the exemplary embodiment, both evoloid pinions 5, 7, as well as the two evoloid output gears 6, 8, are generally constructed as plastic gears.

[0036] In this way, simple production with high running smoothness is observed.

[0037] In contrast, the output pinion 9, as well as the actuating element 10 or the drive pawl 10, are generally made of metal and, in particular, of steel. In fact, the output pinion 9 may be a cold-formed pinion, whereas the drive pawl 10 may be designed as a combined stamped / bent part. Using the actuator shown, reduction ratios for the electric motor 4 of more than 50 to 1 and even 80 to 1 and more can be realized and implemented, so that ultimately and at the drive arm 10b of the drive pawl 10, sufficient force or a sufficiently high torque is available to safely lift the pawl 3 from its locking engagement relative to the rotary latch 2 in the example case.

[0038] List of reference symbols

[0039] Housing 1

[0040] Rotary latch 2

[0041] Lock 2, 3

[0042] Pawl 3

[0043] Electric motor 4

[0044] Evoloid pinion 5, 7

[0045] Evoloid axis 5a, 7a

[0046] Wheel axle 6a, 8a

[0047] Evoloid output gear 6, 8

[0048] Evoloid gears 5, 6, 7, 8

[0049] Drivetrain 5, 6, 7, 8, 9

[0050] Output pinion 9

[0051] Axis 8a, 9a

[0052] Control element 10

[0053] Drive pawl 10

[0054] Tooth segment 10a

[0055] Drive arm 10b

Claims

Patent claims 1. Actuator for automotive applications, in particular for a motor vehicle lock, preferably an actuator integrated into a motor vehicle door lock, comprising an electric motor (4) and an actuating element (10) actuated directly or indirectly by the electric motor (4) via a drive train (5 to 9), wherein the drive train (5 to 9) is equipped with at least one first evoloid gear (5, 6) and a second evoloid gear (7, 8) which are connected to each other, and wherein the respective evoloid gear (5, 6; 7, 8) has an evoloid pinion (5, 7) rotatable about an evoloid axis (5a, 7a) and an evoloid output gear (6, 8) meshing therewith and rotatable about a wheel axis (6a, 8a), characterized in that the two evoloid gears (5, 6; 7, 8) are arranged perpendicular to each other. such that the two evoloid axes (5a, 7a) are mostly perpendicular to each other.

2. Actuator according to claim 1, characterized in that the evoloid axis (5a) and the wheel axis (6a) of one of the two evoloid gear teeth (5, 6) are arranged perpendicular to each other.

3. Actuator according to claim 2, characterized in that the evoloid axis (5a) and the wheel axis (6a) of the first evoloid toothing (5, 6) are arranged mostly perpendicular to each other.

4. Actuator according to one of claims 1 to 3, characterized in that the evoloid axis (5a) of the first evoloid toothing (5, 6) and a drive axis of an output shaft of the electric motor (4) coincide.

5. Actuator according to one of claims 1 to 4, characterized in that the wheel axis (6a) of the first evoloid toothing (5, 6) coincides with the evoloid axis (7a) of the second evoloid toothing (7, 8).

6. Actuator according to one of claims 1 to 5, characterized in that the evoloid axis (7a) and the wheel axis (8a) of the second evoloid toothing (7, 8) are arranged predominantly parallel to each other.

7. Actuator according to one of claims 1 to 6, characterized in that the drive train (5 to 9) is equipped with an output pinion (9) for driving a drive pawl (10) as an actuating element (10).

8. Actuator according to claim 7, characterized in that the drive pawl (10) engages with a tooth segment (10a) in the output pinion (9) and has a drive arm (10b) for actuating a locking mechanism (2, 3) consisting essentially of a rotary latch (2) and a pawl (3).

9. Actuator according to claim 7 or 8, characterized in that the output pinion (9) and the drive pawl (10) are each made of metal, for example steel, while the evoloid pinions (5, 7) and the evoloid output gears (6, 8) are at least partially designed as plastic gears.

10. Motor vehicle lock, in particular motor vehicle door lock, with a locking mechanism (2, 3) consisting essentially of a rotary latch (2) and a locking pawl (3), and with an actuator for the locking mechanism (2, 3), which acts as an opening actuator on the locking pawl (3) and / or as a closing actuator on the rotary latch (3) and is housed together with the locking mechanism (2, 3) in a common housing (1 ), characterized by an actuator according to one of claims 1 to 9.

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