Door drive for a motor vehicle door or motor vehicle flap

Abstract

The invention relates to a door drive for a motor vehicle door or motor vehicle flap. This is generally provided with an electromotive drive (2) and a transmission (3, 4) connected downstream of the drive (2). In addition, a force transmission element (5) is provided, which is operatively connected to a leaf (1) of the motor vehicle door or motor vehicle flap. An output element (4a) of the transmission (3, 4) and the force-transmission element (5) are coupled by a toothing (6, 7, 8) with compensation for play. According to the invention, the toothing (6, 7, 8) is formed in two parts for engaging both into the force transmission element (5) and into a compensation element (9) that is rotatably, elastically coupled to the force transmission element (5). For play-free positioning, the compensation element (9) has a differing angular velocity from the force transmission element (5) in order to create a relative angle (α1 - α2) between the two elements (5, 9).

Description

[0001] The invention relates to a door drive for a motor vehicle door or a motor vehicle tailgate, with an electric motor drive and a gear downstream of the drive, and with a power transmission element which is operatively connected to a leaf of the motor vehicle door or motor vehicle tailgate, wherein an output element of the gear and the power transmission element are coupled by a toothing with play compensation, wherein furthermore the toothing is designed in two parts for engagement on the one hand in the power transmission element and on the other hand in a compensating element which is rotatably and elastically coupled to the power transmission element, and wherein the compensating element has an angular velocity which differs from that of the power transmission element in order to realize a relative angle between the two elements in order to eliminate play.

[0002] Door drives for motor vehicle doors or motor vehicle tailgates are used in a variety of ways in practice and are described, for example, in WO 2017 / 029163 A1. The motor vehicle door moved in this way is typically a motor vehicle side door, for example, a motor vehicle driver's door or a motor vehicle passenger door. The motor vehicle tailgate driven by such a door drive is generally designed as a motor vehicle tailgate, motor vehicle cargo area flap, motor vehicle engine compartment flap, motor vehicle fuel filler flap, motor vehicle hood, etc.

[0003] The force transmission element can be an adjustment part, as described in WO 2017 / 029163 A1, already referenced above. Other force transmission elements, such as gears, are discussed in the further prior art according to DE 43 31 384 A1. In the actuator known from this, a control device is provided that controls a drive motor in such a way that, with each reversal of movement, the drive motor executes a further adjustment path in addition to an adjustment path, which corresponds to the total mechanical play of a transmission element arrangement realized in this way. In this way, very good adjustment accuracy can be provided with minimal cost and space requirements.

[0004] However, in this context, the play is compensated for by the additionally moving drive motor according to signals from the control unit. Such play compensation is typically only noticeable at the end points of a travel range, but is unable to compensate for any component tolerances, wear, and associated play during the travel range. Such play is often noticed by the user and perceived as unpleasant, because the motor-driven leaf of the vehicle door or tailgate can usually also be moved or moved further manually.

[0005] This means that the haptics of door drives for motor vehicle doors or tailgates with play in the drive train need to be improved. In addition to the haptics, the control technology of such door drives also plays a role, whereby play or increasing play over the service life compromises the robustness of such a control system. Furthermore, play or increasing play leads to increased wear over the product's service life.

[0006] There are already other approaches to dampening the movement between an output element and a drive wheel within a certain angular play using a damping device in a load torque lock according to DE 10 2013 206 941 A1. However, the damping described only applies to the angular play of the load torque lock. Typical door drives, however, often also operate with rack and pinion drives, so angular play is not observed in this case.

[0007] Further prior art according to DE 101 14 938 B4 concerns a device for operating an automotive swing door. For this purpose, the device comprises an electric motor, an output gear, and a rack member. Furthermore, a sliding device is provided that supports the rack member. For this purpose, the sliding device is arranged on the inside and / or outside of the rack member and suppresses lateral movement of the rack member.

[0008] The known actuating device according to DE 101 14 938 B4 furthermore shows a prestressing element which is held by a holding element in order to actuate the previously mentioned rack element in the direction of an output gear of a transmission following the electric motor. With the help of the prestressing element, a toothed engagement between the rack element and the output gear is thus ensured. For this purpose, the prestressing element can be designed as a helical spring or leaf spring, or can also be made of rubber and fitted in a press fit. This does indeed provide play compensation, which is provided by the quasi-springy prestressing element. However, fatigue of the prestressing element over longer time scales, increased wear, etc., can often no longer be compensated for in practice.

[0009] DE 298 01 025 U1 concerns an adjustment device for vehicle seats. It comprises a toothed part consisting of a main part and a compensating part. Both parts are connected to each other via an elastic means, in particular a dowel pin, such that, within the range permitted by the elastic means, the compensating part and the main part can assume different spatial arrangements relative to each other.

[0010] The generic and closest prior art according to JP 2005 / 120 693 A concerns a drive for a tailgate. Two meshing gear wheels are used for this purpose. A power transmission element is also used in conjunction with a rotatably elastically coupled compensating element.

[0011] The invention is based on the technical problem of further developing such a door drive for a motor vehicle door or motor vehicle flap in such a way that a perfect play compensation in the drive train of the wing for the motor vehicle door or motor vehicle flap is provided in a simple, durable and robust manner.

[0012] To solve this technical problem, a generic door drive for a motor vehicle door or motor vehicle flap is characterized in the context of the invention in that both the force transmission element and the compensating element are designed in the shape of a circular segment with respect to their respective axis, each with engagement openings for the output element, wherein the output element engages with its toothing via the respective engagement opening on the one hand in an internal toothing of the force transmission element and on the other hand in an internal toothing of the compensating element.

[0013] Within the scope of the invention, play compensation or play elimination takes place between the power transmission element and the compensating element. For this purpose, the power transmission element and the compensating element are elastically coupled to one another. Furthermore, the compensating element has a different angular velocity than the power transmission element to eliminate play. This different angular velocity leads to a relative angle between the two elements, i.e., between the power transmission element and the compensating element. Since both elements are also acted upon by the common output element of the transmission, this differential effect caused by the relative angle between the two elements overall results in any play between the output element and the power transmission element being compensated.

[0014] This is because the power transmission element and the compensating element engage the common output element. For this purpose, the output element is equipped with a split toothing. One part of the toothing interacts with the power transmission element, while the other part is operatively connected with the compensating element. By creating the relative angle between the two elements, the power transmission element is effectively "tensioned" relative to the output element, so that in this way, and through the described differential effect, the play compensation is achieved as desired, practically automatically.

[0015] The overall design ensures that the relative angle between the two elements, which is created by the different angular velocity of the compensation element compared to the force transmission element, is dimensioned such that, on the one hand, maximum play can be compensated for and, on the other hand, the elastic coupling between the two elements is not damaged when the maximum relative angle is reached. This ensures that the relative angle can generally vary depending on the amount of play to be compensated. Such a variation is easily possible thanks to the elastic coupling of both elements.

[0016] For this purpose, the compensating element advantageously operates parallel to the force transmission element. Furthermore, according to a particularly advantageous design, the compensating element is mounted on or at the force transmission element. Typically, an eccentric bearing is used here. This means that the compensating element is mounted on or at the force transmission element eccentrically relative to the force transmission element.

[0017] Furthermore, the design is such that the axis of the compensating element and one axis of the power transmission element are spaced apart from each other in the direction of the output element. In fact, the two axes can be arranged one above the other or one below the other.

[0018] Typically, the design is such that the axis of the compensating element is positioned at a distance above the axis of the power transmission element in the direction of the output element, because the compensating element is generally designed to be "smaller" than the power transmission element. As a result, the compensating element usually also exhibits a higher angular velocity than the power transmission element.

[0019] Advantageous measures of the invention aim in the same direction, whereby the compensating element has a fewer number of teeth than the power transmission element. This assumes the same circumferential speeds on the power transmission element and the compensating element, respectively, because the circumferential speed is ultimately determined by the output element, which, with its two-part toothing, engages the power transmission element on the one hand and the compensating element on the other. The usually realized fewer number of teeth of the compensating element, in conjunction with the axis of the compensating element being arranged above the axis of the power transmission element, results in the compensating element having a higher angular velocity than the power transmission element. This higher angular velocity leads to the relative angle and the differential effect discussed above.

[0020] In principle, of course, a different approach is also possible. In this case, the compensating element is equipped with a greater number of teeth than the power transmission element, and accordingly, the axis of the compensating element is located below or under the axis of the power transmission element in the direction toward the output element.

[0021] The elastic coupling between the two elements typically has a zero position without force transmission. This zero position typically corresponds to the closed position of the wing of the vehicle door or flap relative to the vehicle body. Starting from this zero position, an increasingly increasing relative angle between the two elements causes the elastic coupling, or an elastic element implemented at this point, to be increasingly deflected, thus counteracting the increasing relative angle with an increasing counterforce caused by the deflection.

[0022] According to the invention, the design is such that the output element engages with the internal toothing of both the power transmission element and the compensating element. The configuration is further provided such that both elements are circular segment-shaped, each with an engagement opening for the output element. Because the output element can engage with this engagement opening, both elements are equipped with internal toothing in this case.

[0023] The result is a door drive with effective and virtually automatic play compensation, particularly in the area of ​​its wear zone. For this purpose, the compensating element is assigned to the force transmission element, whereby both elements are elastically coupled to one another. To eliminate play, the compensating element forms a relative angle to the force transmission element, counteracting the force of the elastic coupling or the elastic coupling element provided at this point. This allows for variable play compensation and can, for example, increase over the product's service life, thus ensuring a particularly pleasant feel throughout the entire product life cycle. These are the key advantages.

[0024] The invention will then be explained in more detail with reference to a drawing which merely represents an exemplary embodiment, in which: Fig. 1The door drive for a motor vehicle door or motor vehicle flap in an overview, Figures 2 and 3 the special design of the force transmission element and the compensation element schematically and Fig. 4 the interaction between the force transmission element and the compensation element in an overview.

[0025] The figures show a door drive for a motor vehicle door or motor vehicle flap. Fig. 1For this purpose, a leaf 1 of the motor vehicle door or motor vehicle tailgate in question can be seen. Furthermore, this illustration clearly shows that the door drive, which will be described in more detail below, is arranged in the region of an axis or axis of rotation of the door leaf or door leaf 1, although this is not a mandatory requirement. In any case, the door drive is capable of pivoting the leaf 1 about its axis or axis of rotation. Consequently, the motor vehicle door in the example case is a motor vehicle side door.

[0026] The basic structure of the door drive includes an electric motor drive 2 and a gear 3, 4 connected downstream of the drive 2. The gear 3, 4 operates on a power transmission element 5. The power transmission element 5, in turn, is operatively connected to the leaf 1 of the vehicle door or vehicle tailgate. In principle, however, the power transmission element 5 can also be considered a component of the gear 3, 4. In any case, pivoting movements of the power transmission element 5 are converted into corresponding pivoting movements of the leaf 1.

[0027] It can be seen that an output element 4a of the gear 3, 4 and the power transmission element 5 are coupled by a toothing 6, 7, 8 with play compensation, as best shown in the schematic representation in the Fig. 3 becomes clear.

[0028] According to the exemplary embodiment, the output element 4a is designed as an output-side pinion with toothing 6 connected to the gear wheel 4. The toothing 6 of the output element 4a meshes with a toothing 7 on the one hand and a toothing 8 on the other.

[0029] In fact, the toothing 6, 7, 8 according to the exemplary embodiment and according to the invention is divided into two parts. This is because the toothing 6, 7, 8 causes, on the one hand, the output element 4a to engage with the power transmission element 5, and, on the other hand, the output element 4a to simultaneously engage with a compensating element 9. The power transmission element 5 and the compensating element 9 are elastically coupled to one another in a rotatable manner, with an elastic coupling element 10 according to the exemplary embodiment being used for this purpose. The elastic coupling element 10 can be a rubber element or a spring.

[0030] It can be seen that the output element 4a is equipped with toothing 6. The power transmission element 5, in contrast, has toothing 7. Finally, the compensating element is equipped with toothing 8. The toothing 6, 7, 8 is divided in such a way that the toothing 6 on the output element 4a is, on the one hand, coupled to the internal toothing 7 of the power transmission element 5. On the other hand, a further toothing is realized between the toothing 6 of the output element 4a and the toothing 8 of the output element 9, which differs from the toothing 7. The toothing 8 is also an internal toothing 8.

[0031] The overall design is such that the elastic coupling or elastic coupling element 10 between the two elements 5, 9 has a zero position without force transmission. This zero position corresponds to the closed position of the wing 1 relative to the vehicle body (not shown in detail).

[0032] It can be seen that both the power transmission element 5 and the compensating element 9 are designed as a circular segment, specifically with respect to their respective axes 11 and 12, respectively. Furthermore, both elements 5, 9, in the exemplary embodiment, each have an engagement opening 13, 14 for the output element 4a. Via this engagement opening 13, 14, the output element 4a can engage with its toothing 6, on the one hand, with the internal toothing 7 of the power transmission element 5 and, on the other hand, with the internal toothing 8 of the compensating element 9, as described.

Claims

1. Door drive for a motor vehicle door or motor vehicle flap, with an electromotive drive (2) and a transmission (3, 4) connected downstream of the drive (2), and with a force transmission element (5) which is operatively connected to a leaf (1) the motor vehicle door or motor vehicle flap, wherein an output element (4a) of the transmission (3, 4) and the force transmission element (5) are coupled by a toothing (6, 7, 8) with compensation for play, wherein further the toothing (6, 7, 8) is designed in two parts for engaging in both the force transmission element (5) and a compensating element (9) that is rotatably, elastically coupled to the force transmission element (5), and wherein for play-free positioning, the compensation element (9) has a differing angular velocity from the force transmission element (5) in order to create a relative angle (α1 - α2) between the two elements (5, 9), characterized in that both the force transmission element (5) and the compensation element (9) are designed in the form of a circle segment relative to their respective axes (11, 12), each having engagement openings (13, 14) for the output element (4a), wherein the output element (4a) engages with its toothing (6) on the one hand in an inner toothing (7) of the force transmission element (5) and on the other hand in an inner toothing (8) of the compensation element (9) through the respective engagement opening (13, 14).

2. Door drive according to Claim 1, characterized in that the compensating element (9) is effective parallel to the force transmission element (5).

3. Door drive according to Claim 1 or 2, characterized in that the compensating element (9) is mounted against or on the force transmission element (5) and eccentrically relative thereto.

4. Door drive according to any one of Claims 1 to 3, characterized in that an axis (11) of the compensating element (9) and an axis (12) of the force transmission element (5) are arranged at a distance one above or below the other towards the output element (4a).

5. Door drive according to any one of Claims 1 to 4, characterized in that the compensating element (9) has a smaller number of teeth than the force transmission element (5).

6. Door drive according to any one of Claims 1 to 5, characterized in that the elastic coupling between the two elements (5, 9) has a zero position with no force transmission.

7. Door drive according to Claim 6, characterized in that the zero position corresponds to the closed position of the leaf (1) with respect to a motor vehicle body.

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