Electromotive drive for motor vehicle applications

Abstract

The invention relates to an electromotive drive (2, 3, 4, 5, 6, 7) for motor vehicle applications, in particular an electromotive drive (2, 3, 4, 5, 6, 7) in or on a motor vehicle lock (1). The invention preferably relates to a closing drive (2, 3, 4, 5, 6, 7) for the locking mechanism of a motor vehicle lock (1). For this purpose, the electromotive drive (2, 3, 4, 5, 6, 7) is provided with an electric motor (2), a transmission (4, 5, 6, 7) downstream of the electric motor (2), and a cable (10) which is connected on the output side of the transmission (4, 5, 6, 7) for acting on an actuating element (11). The cable (10) is acted upon by means of a cam disk (6) which has a varying radius (r1,r2) as seen over the drive path (a) of the actuating element (11). According to the invention, the cam disk (6) is formed as a component of the transmission (4, 5, 6, 7).

Description

[0001] INTERNAL

[0002] Kiekert AG

[0003] P24148WO

[0004] 1

[0005] Description

[0006] Electric motor drive for automotive applications

[0007] The invention relates to an electric motor drive for automotive applications, in particular an electric motor drive in or on a motor vehicle lock, preferably a closing drive for the locking mechanism of a motor vehicle lock, comprising an electric motor, further comprising a gearbox following the electric motor, and a cable pull connected on the output side of the gearbox for actuating an actuator, wherein the cable pull is actuated by means of a cam disk which has a varying radius over the drive path of the actuator.

[0008] Electric motor drives are used in and on motor vehicles in a wide variety of applications. For example, such actuators are used for adjusting mirrors, headlights, seats, or even raising and lowering windows, etc. Tasks such as locking fuel filler caps, charging port covers, or similar flaps are also conceivable and can be implemented using such electric motor drives. Typically, these electric motor drives are used in conjunction with vehicle locks and door locks.

[0009] Here, it is conceivable to design and position the electric motor drive as a separate unit, both physically and functionally, from the vehicle lock. The mechanical connection between the electric motor drive and the vehicle lock is then provided via a cable or Bowden cable. However, such an electric motor drive can also be arranged inside the housing of the corresponding vehicle lock.

[0010] Kiekert AG

[0011] P24148WO

[0012] 2

[0013] Electric motor drives for automotive applications must not only be adapted to the prevailing temperatures, which can range from -40 °C to +80 °C and even higher, but also require the necessary dust and moisture resistance. Furthermore, such electric motor drives are typically operated with low-voltage direct current, meaning that the high-speed electric motor usually used in this application must be geared down to achieve the required actuation movements of the output actuator. This necessitates a compact gearbox with a high gear ratio to accommodate the typically limited installation space and meet the requirements for minimal weight.

[0014] Such electromechanical drives for automotive applications are described, for example, in FR 2 915 226 A1 and DE 10 2021 121 456 A1. The latter describes a so-called auxiliary locking drive for the motorized adjustment of the latch of a vehicle lock during an auxiliary locking process. In this process, the cable between the electromechanical drive or auxiliary locking drive and the vehicle lock is actuated by means of a cam disc, which in turn is set in rotation by an associated gearbox.

[0015] Comparable arrangements are known from EP 3093418 A1. These arrangements utilize, among other things, a pulley or cam disc equipped with a diameter that varies around its circumference. This is intended to provide a variable transmission ratio and power transfer on the output side.

[0016] The generic and therefore closest prior art according to WO 2014 / 131390 A2 of the applicant concerns a motor vehicle door lock equipped with a closing / opening device with drive and transmission element. The drive in this context is INTERNAL.

[0017] Kiekert AG

[0018] P24148WO

[0019] 3

[0020] The torque is variable. Furthermore, the transmission element is subjected to a torque, and consequently a force, that depends on the drive path. For this purpose, a cam disc equipped with a spiral control contour is provided, the radius of which increases from a center point towards the circumference of the cam disc.

[0021] The state of the art has generally proven its worth, but still offers room for further improvements. In practice, the standard approach is to provide at least one cam or pulley located separately from the output side of the gearbox. This necessitates additional installation space for the pulley. Furthermore, such designs are considerably heavy. While the varying radius of the cam along the drive path of the actuating element in the generic prior art according to WO 2014 / 131390 A2 ensures that the specific requirements, particularly for engaging the locking mechanism of a motor vehicle lock, are met, this has so far only been achieved with considerable effort. The invention aims to remedy this.

[0022] The invention is based on the technical problem of further developing such an electric motor drive for automotive applications in such a way that the design and monetary costs are reduced and a simultaneously compact and weight-reduced embodiment is achieved.

[0023] To solve this technical problem, the invention proposes, starting from an electric motor drive for automotive applications, that the cam disc is designed as a component of the transmission.

[0024] In contrast to the generic prior art according to WO 2014 / 131390 A2, the invention proceeds in such a way that the INTERNAL

[0025] Kiekert AG

[0026] P24148WO

[0027] 4

[0028] The cam disc is not implemented and realized separately and additionally from the transmission. Rather, the cam disc itself constitutes an integral part of the transmission. For this purpose, the cam disc is advantageously designed as a transmission gear or a component thereof. Most often, the cam disc is an integral part of the transmission gear, so that, according to the invention, an additional cam disc can be omitted, and instead, one of the transmission gears of the standard transmission additionally assumes the function of the cam disc.

[0029] In this way, the already known advantages are achieved unchanged. That is, due to the varying radius of the cam disc, as seen from the actuator's drive, the electric motor drive is particularly well-suited as a door closer drive. This is because, with such a door closer drive, a small force is initially required for the closing movement at the beginning of the actuator's travel, which increases towards the end of the travel. This can be attributed to the fact that the force transmitted from the drive via the cam disc to the locking mechanism when closing the corresponding door increases over the travel of the drive. The reason for this is that, towards the end of the travel, the seal closing the respective vehicle door must be increasingly compressed.This required force, which increases along the drive path, has so far been met in practice by relatively large, heavy and expensive drives.

[0030] If, within the framework of the prior art defined by WO 2014 / 131390 A2, the cam disc with a spiral control contour is used, the radius of which increases from a center point towards the circumference of the cam disc, the cam disc is always provided on the output side and in addition to the gearbox. That is to say, any integration of the cam disc into the gearbox has not been considered possible in the prior art to date. INTERNAL

[0031] Kiekert AG

[0032] P24148WO

[0033] 5

[0034] This can be attributed to the fact that conventional gearboxes, with their gears, are equipped with teeth on the outer circumference that mesh with the teeth of adjacent gears. This means that without additional modification of these gears and / or the use of a special gearbox, integrating the cam disc into the gearbox or as a component of the gearbox is not possible. Furthermore, the dual function of the gear, achieved according to the invention—both as a component of the gearbox and as a cam disc—cannot be implemented simply. This is where the essential advantages lie.

[0035] In an advantageous embodiment, the cam disc is provided on the outer circumference of the gear wheel or defines this outer circumference. To implement this in detail, the gear wheel can be designed as a hollow gear. In this case, the hollow gear in question has internal teeth and is, for example, designed as a hollow gear in a planetary gear set with sun gear, planet gears, ring gear, and planet carrier.

[0036] Alternatively or additionally, the gear can also be designed as a carrier gear for at least one connected gear. In this case, the gear can be designed as a conventional spur gear, for example, in a spur gear transmission. The spur gear or gear in question may then be mounted on the carrier gear, which in turn acts as the cam.

[0037] However, it is also possible for the carrier wheel to be equipped with several gears. One or more gears can be rotatably connected to a carrier wheel surface. The carrier wheel surface is enclosed by an outer circumference. In this way, the outer circumference of the carrier wheel surface can function as a cam or assume the function of such a cam and be designed as such. Thus, while the carrier wheel surface provides for the mounting and bearing of the several gears, the carrier wheel surface is INTERNAL

[0038] Kiekert AG

[0039] P24148WO

[0040] 6

[0041] The outer circumference of the carrier wheel is designed as a cam disk. Such an embodiment is particularly suitable if the carrier wheel is designed as the planet carrier of the previously mentioned planetary gear set.

[0042] As previously explained, integrating the cam disc into the gearbox, or designing the cam disc as a component of the gearbox, requires either modifying individual gearbox gears and / or using a special gearbox design. In the first case of modification, it is conceivable to rotatably mount a conventional gearbox gear, for example, the spur gear of a spur gearbox, on an additional carrier gear, which itself incorporates the cam disc on its outer circumference. In this case, the spur gear and the carrier gear together define the gearbox gear with the cam disc as a component of the gearbox.

[0043] A particularly elegant solution is observed when the gear equipped with the cam disc is designed as the ring gear of the planetary gear set. In this case, the outer circumference of the ring gear takes over the function of the cam disc with a varying radius over the drive path of the actuator, thus performing a dual function as both a gear wheel or gear on the one hand and a cam disc on the other. The same applies if the carrier gear is the planet carrier of the aforementioned planetary gear set.

[0044] In all these cases, the procedure is regularly such that the cam disc has a preferably uniformly increasing outer radius over the drive path of the actuating element. The actuating element is basically any element on which the electromechanical drive according to the invention acts in order to realize corresponding positioning movements of this actuating element. In the event that the electromechanical drive is used as a closing drive for the locking mechanism of an INTERNAL

[0045] Kiekert AG

[0046] P24148WO

[0047] 7

[0048] When used in a motor vehicle lock, the actuating element is, for example, a pull-in latch that can be engaged with a rotary latch of the locking mechanism, with the help of which the rotary latch is actuated in a pulling direction.

[0049] The outer radius of this cam increases over the travel of the actuator or closing latch. This means that as the travel of the rotary latch increases in the closing direction, and the corresponding counterforces of the compressed door seal increase, so does the torque provided on the output side. This can be attributed to the increasing outer radius of the cam. This outer radius of the cam generally increases uniformly, i.e., it has a constant increase in radius for every angle of rotation of the cam. Of course, it is also possible to make the increase in the outer radius of the cam progressive over the travel of the actuator, i.e., in the sense that the radius doubles, for example, every 5° or 10° of travel of the cam.

[0050] It has proven particularly advantageous when the cam disc and the gear are designed as a single-piece plastic component. In most cases, all gears of the transmission are designed as plastic components to keep the weight of the electromechanical drive according to the invention low. This also results in cost advantages. Furthermore, such gears are characterized by particularly quiet operation.

[0051] In any case, the possibility of designing the cam and the gear as a single plastic component opens up the possibility of manufacturing the cam and the gear together in one step. This eliminates additional and separate assembly steps for the cam, because it can be installed immediately after the gearbox and internally.

[0052] Kiekert AG

[0053] P24148WO

[0054] 8

[0055] especially the planetary gear. Therefore, it is only necessary afterwards to hook the cable or the Bowden cable connected at this point into the cam disc in question.

[0056] The invention also relates to a motor vehicle lock, and in particular a motor vehicle door lock, which is equipped with a locking mechanism and a closing drive for the locking mechanism. Within the scope of the invention, the closing drive is the electromechanical drive described in detail above.

[0057] The result is an electric motor drive that is not only exceptionally robust and adapted to the specific requirements of vehicles, but also operates very quietly, is cost-effective, easy to install, and optimized in terms of weight. These are its key advantages.

[0058] The invention will now be explained in more detail with reference to a drawing that illustrates only one embodiment; the drawing shows:

[0059] Fig. 1 shows an overview of the electromechanical drive according to the invention and

[0060] Fig. 2 shows a detail of the gearbox as illustrated in Fig. 1.

[0061] The figures show an electric motor drive 2, 3, 4, 5, 6, 7 for automotive applications. Specifically, in this embodiment, it is a closing drive 2, 3, 4, 5, 6, 7 for a vehicle lock 1. In this context, one might also refer to it as a so-called auxiliary closing drive 2, 3, 4, 5, 6, 7, which is spatially and functionally separate from the vehicle lock 1 within the internal

[0062] Kiekert AG

[0063] P24148WO

[0064] 9

[0065] The motor vehicle door is arranged as indicated in Fig. 1. For this purpose, the electric motor drive 2, 3, 4, 5, 6, 7 is arranged in a housing 9 surrounding it and mechanically connected to the motor vehicle lock 1 via a cable 10 or a Bowden cable 10, taking into account an optional deflection pulley 8.

[0066] In fact, the electric motor drive 2, 3, 4, 5, 6, 7, which will be described in detail below, can exert a pulling motion, indicated in Fig. 1, on a pull-tab 11 at the output side of the cable or Bowden cable 10. This pull-tab, in turn, engages a rotary latch 12, which is part of a locking mechanism inside the vehicle lock 1, in a pulling direction. This corresponds to the clockwise rotation of the rotary latch 2, also indicated in Fig. 1. As a result, the vehicle door is increasingly pulled towards the indicated bodywork, compressing the circumferential seal in the door opening. This is accompanied by an increasing counterforce, particularly from the seal, which must be compensated by the illustrated pull-tab drive 2, 3, 4, 5, 6, 7.

[0067] For this purpose, the illustrated electromechanical drive or closing drive 2, 3, 4, 5, 6, 7 provides on the output side a force or closing force that increases over the drive path a of the actuating element or the closing latch 11.

[0068] This increasing force is provided by a cam 6, which has a varying radius n, r2 over the drive path a of the actuating element 11. Reference is made to Fig. 2, which shows the cam 6 in detail. It can be seen that the cam 6 is equipped with an increasing outer radius n, r2, which grows from an initially observed value ri to a final value r2, taking into account an actuating path a of 90° swept by the two radii n, r2 indicated in Fig. 2, which corresponds to the INTERNAL

[0069] Kiekert AG

[0070] P24148WO

[0071] 10

[0072] The drive path a of the actuating element 11 coincides with or defines it accordingly. This is because the cable or Bowden cable 10 is hooked into the cam disc 6 in question and is actuated when the cam disc 6 rotates over the increasing radius n, r2.

[0073] As a consequence of the increasing radius n, r2 along the travel path or the angle a of 90° in the example of the cam disc 6, the cable or Bowden cable 10 in contact with the cam disc 6 is subjected to a correspondingly increasing lever arm. This, in turn, corresponds to an increase in the closing force provided by the cable or Bowden cable 10 on the output side. This compensates for the increasing counterforces of the circumferential door rubber seal during a closing operation. It can be seen that the cam disc 6 is equipped with a uniformly increasing outer radius n, r2 over the drive path a of the actuating element 11. That is, the increase in radius for each, for example, 5° of angle a is constant according to the exemplary embodiment. Of course, progressive increases are also conceivable, in the sense that the radius n, r2 doubles for each 5° of angle a.However, this is not shown.

[0074] Of particular importance is the fact that the cam disc 6, previously described in detail, is designed as part of a gearbox 4, 5, 6, 7 of the electric motor drive 2, 3, 4, 5, 6, 7. This becomes clear when comparing the illustrations in Figures 1 and 2.

[0075] In fact, the electric motor drive 2, 3, 4, 5, 6, 7 initially comprises an electric motor 2, which is equipped on its output shaft with a drive worm for an external gear 3. A sun gear 4 of the gear set 4, 5, 6, 7, designed as a planetary gear set 4, 5, 6, 7, is rotationally fixed to the gear 3. The sun gear 4 meshes with rotating INTERNAL

[0076] Kiekert AG

[0077] P24148WO

[0078] 11

[0079] Planet gears 5 rotate inside a ring gear 6. The planet gears 5 are in turn supported by a planet carrier 7.

[0080] It can be seen that the cable 10 connected to the output side of the gearbox or planetary gear 4, 5, 6, 7 actuates the actuating element 11, specifically, according to the exemplary embodiment, by pulling in the sense of a pull-in drive. For this purpose, the cable 10 is guided over the deflection pulley 8 and is connected to the gearbox 4, 5, 6, 7 via the previously mentioned cam disc 6. The gearbox 4, 5, 6, 7 has the special feature that the cam disc 6 is an integral part of the gearbox 4, 5, 6, 7.

[0081] In fact, the cam disc 6 is designed as a gear 6, specifically as a ring gear 6 of the planetary gear set 4, 5, 6, 7. That is, according to the exemplary embodiment, the cam disc 6 and the ring gear 6 of the planetary gear set 4, 5, 6, 7 function together. Furthermore, the design is such that the cam disc 6 and the respective gear 6, or ring gear 6, of the planetary gear set 4, 5, 6, 7 are formed as a single-piece plastic component. This is possible because the ring gear 6 has the necessary internal teeth for the planet gears 5 that roll on it, while the outer circumference of the ring gear 6 is equipped with the increasing radius n, r2 and consequently functions as a cam disc 6 for connecting the cable or Bowden cable 10. The cam disc 6 in question may also...The ring gear 6 is designed on its outer circumferential side with a groove to accommodate a core of the cable pull 10, which is not shown in detail.

[0082] It is also possible, in principle, for the cable or Bowden cable 10 to be connected to the planet carrier 7. However, this is not shown in detail. In this case, the planet carrier 7 takes on the function of a carrier gear 7 or gear 7. The individual gears 5 or planet gears 5 are each rotatably mounted to an internal carrier gear surface.

[0083] Kiekert AG

[0084] P24148WO

[0085] 12

[0086] connected, while an outer circumference of the carrier wheel surface takes over the function of the cam disc 6.

[0087] Depending on whether either the ring gear 6 or the planet carrier 7 of the planetary gear set 4, 5, 6, 7 is locked, a rotary motion of the electric motor 2, transmitted via the sun gear 4, causes the ring gear 6 or the planet carrier 7 to rotate in a complementary manner. In the exemplary embodiment, the design is such that the planet carrier 7 is generally locked or stationary, so that the counterclockwise rotary motion of the sun gear 4 indicated in Fig. 1 results in a counterclockwise motion of the planet gears 5 inside the ring gear 6. Since the planet carrier 7 is stationary, the planet gears 5 rolling inside the ring gear 6 cause the ring gear 6 to pivot counterclockwise, as shown in Fig. 1.

[0088] This counterclockwise movement of the ring gear 6, as shown in detail in Fig. 2, results in the inner cable of the cable 10, which is inserted into the groove of the cam disk 6 or the ring gear 6, initially being subjected to a (small) torque corresponding to the small radius n. This torque increases with increasing positioning movement according to the positioning angle α of the ring gear 6 and thus the positioning movement of the actuating element 11 or the pawl. As a consequence, not only is the rotary latch 12 actuated in a closing direction by means of the pawl 11, but this also occurs with increasing torque because the radius has increased from the value n to the final value r2 at the end of the positioning angle α or at the end of the drive travel of the actuating element 11. This increasing torque, with which the cable 10 or thewhose soul is actuated, leads to a corresponding increase in the closing force provided on the output side by the electric motor drive 2, 3, 4, 5, 6, 7. This takes into account the increasing counterforce built up by the circumferential door rubber seal. INTERNAL.

[0089] Kiekert AG

[0090] P24148WO

[0091] 13

[0092] All this is achieved while maintaining a cost-effective and lightweight design, because the planetary gear set 4, 5, 6, 7 is constructed entirely of plastic gears 4, 5, 6, 7, which also ensure particularly quiet operation. At the same time, a significant reduction in the rotational speed of the high-speed output shaft of the electric motor 2 is provided.

[0093] Kiekert AG

[0094] P24148WO

[0095] 14

[0096] Reference symbol list

[0097] 1 motor vehicle lock

[0098] 2, 3, 4, 5, 6, 7 electric motor drive, pull-in drive

[0099] 4, 5, 6, 7 Gearbox, planetary gearbox, plastic gears 2 Electric motor

[0100] outer gear

[0101] 4 sun wheel

[0102] 5 planetary gears

[0103] 6 Cam disc, gear wheel, hollow gear, ring gear 7 Planetary gear carrier, carrier gear, gear wheel

[0104] 8 pulley

[0105] 9 cases

[0106] 10 Cable, Bowden cable

[0107] 11 Pull latch, adjusting element

[0108] 12 Rotary Trap

[0109] n, r2 varying radius

Claims

INTERNAL Kiekert AG P24148WO 15 Patent claims 1. An electric motor drive (2, 3, 4, 5, 6, 7) for automotive applications, in particular an electric motor drive (2, 3, 4, 5, 6, 7) in or on a motor vehicle lock (1), preferably a pull drive (2, 3, 4, 5, 6, 7) for locking a motor vehicle lock (1), comprising an electric motor (2), further comprising a gearbox (4, 5, 6, 7) following the electric motor (2), and a cable pull (10) connected on the output side of the gearbox (4, 5, 6, 7) for actuating an actuator (11), wherein the cable pull (10) is actuated by means of a cam disk (6) which has a varying radius (n, r2) over the drive path (a) of the actuator (11), characterized by the fact that the cam disc (6) is designed as part of the transmission (4, 5, 6, 7).

2. Drive (2, 3, 4, 5, 6, 7) according to claim 1 , characterized in that the cam disk (6) is designed as a gear wheel (6) or part thereof.

3. Drive (2, 3, 4, 5, 6, 7) according to claim 1 or 2, characterized in that the cam disk (6) is provided on or defines the outer circumference of the gear wheel (6).

4. Drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 3, characterized in that the gear (6) is designed as a hollow gear (6) with internal teeth, for example as a hollow gear (6) of a planetary gear (4, 5, 6, 7). INTERNAL Kiekert AG P24148WO 16 5. Drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 4, characterized in that the transmission (4, 5, 6, 7) has a carrier wheel (7) for at least one gear (5) connected thereto.

6. Drive (2, 3, 4, 5, 6, 7) according to claim 5, characterized in that the carrier wheel (7) is equipped with several gears (5) which are rotatably connected to a carrier wheel surface, while an outer circumference of the carrier wheel surface is designed as a cam disk (6).

7. Drive (2, 3, 4, 5, 6, 7) according to claim 5 or 6, characterized in that the carrier wheel (7) is designed as a planet gear carrier (7) of the planetary gear set (4, 5, 6, 7).

8. Drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 7, characterized in that the cam disk (6) has a preferably uniformly increasing outer radius (n, r2) as seen over the drive path (a) of the actuating element (11).

9. Drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 8, characterized in that the cam disk (6) and the gear wheel (6) are designed as a one-piece plastic component.

10. Motor vehicle lock (1), in particular motor vehicle door lock (1), with a locking mechanism and a closing drive (2, 3, 4, 5, 6, 7) for the locking mechanism, characterized by the fact that the closing drive (2, 3, 4, 5, 6, 7) is designed as an electromotor drive (2, 3, 4, 5, 6, 7) according to one of claims 1 to 9.

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