ELECTROMOTIVE DRIVE FOR MOTOR VEHICLE APPLICATIONS

Abstract

An electromotive drive for motor vehicle applications, in particular for applications for and in a motor vehicle lock. For this purpose, the drive is equipped with an electric motor, a drive disk which can be actuated by the electric motor and can be rotated about an axis, and at least one spring assigned to the drive. The spring transmits a force to the drive disk which aids the drive within the scope of the invention.

Claims

1. An electromotive drive for motor vehicle applications, the electromotive drive comprising: an electric motor, a drive disk which is actuated by the electric motor and is rotated about an axis, and at least one spring functionally assigned to the drive disk, wherein the spring transmits a force to the drive disk which aids the electromotive drive, and wherein the spring is a leg spring which is fixed in place via ails wound portion of the leg spring to a pin, and wherein the leg spring interacts via a drive leg of the leg spring with a contour on the drive disk.

2. (canceled)

3. The electromotive drive according to claim 1, further comprising a first stop, wherein a fixed leg of the leg spring rests against the first stop.

4. The electromotive drive according to claim 3, wherein the leg spring is pretensioned in an initial position such that the drive leg, in contact with the contour, spreads out increasingly relative to the fixed leg toward an extended position in order to aid the drive during operation of the drive.

5. The electromotive drive according to claim 1, wherein the drive disk is circular, with the axis as a center point, and the contour extends concentrically relative to the axis and in an arcuate shape.

6. The electromotive drive according to claim 1, wherein the drive leg is equipped with an extension arm which interacts with a cam on the drive disk for positioning of the drive disk.

7. The electromotive drive according to claim 6, wherein the extension arm has a latching contour that engages around the cam.

8. The electromotive drive according to claim 7, wherein the cam engages in the latching contour as soon as the drive disk assumes a predetermined position.

9. The electromotive drive according to claim 1, wherein an electrical current applied to the electric motor is detected as a function of the force built up by the spring.

10. The electromotive drive according to claim 9, further comprising a control unit, wherein the control unit controls a position of the drive disk as a function of the current consumed by the electric motor.

11. The electromotive drive according to claim 10, wherein the control unit further controls a position of the drive disk as a function of the force built up by the spring.

12. The electromotive drive according to claim 8, wherein the predetermined position is an end position of the drive disk.

13. The electromotive drive according to claim 6, wherein the contour and the cam are positioned on an underside of the drive disk opposite from an upper side of the drive disk that includes an actuating contour.

14. The electromotive drive according to claim 1, wherein the electric motor includes an output shaft with an output worm that interacts with toothing of a drive worm on the drive disk.

15. The electromotive drive according to claim 4, wherein in the extended position the drive leg of the leg spring rests against a second stop.

16. A motor vehicle lock comprising: a pawl and a catch, and the electromotive drive according to claim 1, wherein the electromotive drive is an electromotive opening drive and during an opening process of the motor vehicle lock, the drive disk with assistance of the leg spring operates the pawl to lift the pawl from a latching engagement with the catch.

17. The motor vehicle lock according to claim 16, wherein in a closed position of the motor vehicle lock, the leg spring is pretensioned in an initial position against the drive disk to yield stored energy to the drive disk by spreading out toward an extended position during the opening process.

Description

[0024] The invention is explained in greater detail below with reference to a drawing which shows only one exemplary embodiment. In the drawing:

[0025] FIGS. 1 and 2 show the electromotive drive according to the invention during an opening process,

[0026] FIGS. 3 and 4 show the electromotive drive during the return movement,

[0027] FIG. 5 shows a modified embodiment of the drive according to FIGS. 1 to 4,

[0028] FIGS. 6 and 7 show a further third embodiment.

[0029] The figures show an illustration of an electromotive drive unit for automotive applications. In the exemplary embodiment, the electromotive drive is an opening drive for a motor vehicle lock, which is shown and reproduced with its essential components in FIG. 1. In fact, a locking mechanism 1, 2 of the motor vehicle lock in question, which is or can be a motor vehicle door lock, can be seen at this point and in the front view. The locking mechanism 1, 2 is composed of a catch 1 and a pawl 2.

[0030] In addition, a release lever 3 is also realized, by means of which the pawl 2 can be lifted from its latching engagement with the catch 1 (in the illustrated closed position of the locking mechanism 1, 2). For this purpose, the release lever 3 performs a clockwise movement about its axis, such that the pawl 2 is thereby lifted counterclockwise from its latching engagement with the catch 1 in the closed position of the locking mechanism 1, 2 shown in FIG. 1. As a result, the catch 1 opens in a spring-assisted manner, namely in the clockwise direction, and releases a previously captive locking bolt, indicated in the drawing. As a result, an associated motor vehicle door can be opened directly.

[0031] The electromotive drive is provided and designed to open the locking mechanism 1, 2 and/or to actuate the release lever 3 as a functional element or functional unit. The electromotive drive comprises an electric motor 4. The electric motor 4 has on its output shaft an output worm 5 which interacts with a drive disk 6 by virtue of the output worm 5 engaging in a toothing of the drive worm 6 and causing said drive worm to rotate about an axis 7 in the clockwise direction and in the counterclockwise direction, as shown by a double-headed arrow in FIG. 1.

[0032] An actuating contour 8 is provided on an upper side of the drive disk 6 and is designed to pivot the release lever 3 in the counterclockwise direction about its axis in order to open the locking mechanism 1, 2. This corresponds to a clockwise movement of the drive disk 6 in the front view or when looking at the upper side of the drive disk 6.

[0033] In contrast, the opposite underside of the drive disk 6, which is likewise shown in FIG. 1, is equipped with a spring 9 assigned to the electromotive drive on the one hand and a contour 10 on the other hand on the drive disk 6. The opening movement of the drive disk 6 in the clockwise direction in relation to the upper side of the drive disk 6 consequently corresponds to the drive disk 6 performing a counterclockwise movement about its axis 7 when viewed from the underside of the drive disk 6. In fact, the spring 9 is designed such that it transmits a force supporting the drive to the drive disk 6.

[0034] According to the exemplary embodiment, the spring 9 is designed as a leg spring. For this purpose, the spring 9 has a wound portion 9a which is connected in a stationary manner to a pin 11. According to the embodiment and not in a limiting manner, the pin 11 is connected to a motor vehicle lock housing 12.

[0035] In addition to the wound portion 9a, the leg spring 9 has two legs 9b, 9c. The leg 9b is a drive leg 9b which interacts with the previously explained contour 10 on the drive disk 6 (on the underside thereof). In contrast, the other leg 9c is formed as a fixed leg 9c of the leg spring 9 and rests against a stop 13. Like the pin 11, the stop 13 is (in one piece) connected to the lock housing 12 (made of plastic).

[0036] The drive leg 9b of the spring and/or leg spring 9 ensures the assistance to the electromotive drive or the assistance to the drive disk 6 during an opening process. This opening process of the drive disk 6 corresponds to a movement of the drive disk 6 in the counterclockwise direction in relation to the axis 7, and in the bottom view or the view of the underside of the drive disk 6, as can be understood by observing FIGS. 1 and 2 in sequence.

[0037] During this opening process, the drive leg 9b of the spring or leg spring 9 rests against the contour 10 of the drive disk 6 and spreads increasingly in relation to the stationary fixed leg 9c during the opening process. This is possible because the spring 9 is under tension in the initial position G or neutral position shown in FIG. 1. The tension of the spring 9 is reflected by the relatively small angle ? between the drive leg 9b and the fixed leg 9c, which according to the exemplary embodiment is approximately 40 to 50?. During the course of the opening process during the transition from FIG. 1 to FIG. 2, the drive leg 9b then spreads relative to the fixed leg 9c until the end position E of the drive disk 6 shown in FIGS. 2 and 3 is approximately present and is observed. The two legs 9b, 9c then form an angle ? of approximately 110? to 120?. Since the spring or leg spring 9 is relaxed in this case, the spring energy or tension energy released in this way can be used to aid the movement of the drive disk 6 and thus of the entire drive.

[0038] As soon as the drive leg 9b has spread away from the fixed leg 9c and the drive disk 6 has reached its end position E shown in FIGS. 2 and 3, the drive leg 9b moves against a further stop 14. Like the stop 13 and the pin 11, this is generally integrally connected to the lock housing 12. Correspondingly, the stop 14 is made of plastic.

[0039] Starting from the end position E according to FIG. 3, during a return in the transition from FIG. 3 to FIG. 4, the drive disk 6 then performs a clockwise movement during the transition from FIG. 3 to FIG. 4 in the opposite direction to the opening movement in the counterclockwise direction in the view of the underside of FIGS. 1 and 2. In this process, the spring 9 or leg spring is increasingly tensioned, because the drive leg 9b is increasingly moved toward the fixed leg 9c abutting the contour 10, and thus the spring 9 acquires the required tension energy.

[0040] On the basis of the figures, it can be seen overall that the drive disk 6 is circular in form, with the axis 7 as a center point. In addition, the contour 10 interacting with the spring 9 is concentric in comparison thereto, and is of arcuate design. That is to say, the arc defining the contour 10 uses the axis 7 as a center point for its radial extension. FIG. shows a variant in which the drive leg 9b is equipped with an extension arm 9b. The extension arm 9b has a latching contour 15 which is designed as a convexity or recess in the extension arm 9b in question. In addition, a cam 16 is provided and realized on the underside of the drive disk 6, which engages in the latching contour 15 as soon as the drive disk 6 assumes a corresponding position. According to the exemplary embodiment, the interaction between the latching contour 15 and the cam 16 occurs as soon as the drive disk 6 has assumed its end position E shown in FIG. 5. The drive leg 9b then also rests against the stop 14. In principle, the described interaction between the latching contour 15 and the cam 16 can also be present and can be realized in any other position of the drive disk 6.

[0041] Finally, in the further and third exemplary embodiment according to FIGS. 6 and 7, a control unit 17 is provided, by means of which the electric motor 4 and thus the entire electromotive drive are actuated and supplied with energy. The control unit 17 can then detect an electrical current applied to the electric motor 4. For this purpose, the current consumption at the electric motor 4 can be measured directly or can be detected by means of a sensor (not shown). This electrical current consumed by the electric motor 4 and applied thereto is then dependent on the force built up by the spring 9.

[0042] A corresponding and schematic dependence is shown in FIG. 7. Here, the current consumed by the electric motor 4 is shown in relation to the path traveled by the drive disk 6, which is manifested in an associated pivot angle of the drive disk 6 about its axis 7. The pivot angle and/or angle in question is shown and reproduced between the initial position G and the end position E of the drive disk 6. It can be seen that the current consumed by the electric motor 4 increases in the direction toward the initial position or base position G, because the spring 9 is tensioned in the direction of the initial position G. In contrast, the current consumption in the direction of the end position E decreases, because in this direction the spring 9 aids the movement of the drive disk 6 and thus of the entire electromotive drive.

[0043] On the basis of the positional dependence of the current consumed by the electric motor 4, as is very generally represented in FIG. 7, there is the possibility for the control unit 17 to control the position of the drive disk 6 in a precise manner as a function of the current consumed by the electric motor 4. This means that, if the dependence between the current consumed by the electric motor 4 on the one hand and the angular position of the drive disk 6 on the other hand between the initial position G and the end position E is stored in the control unit 17, schematically shown in FIG. 7, for example by a calibration process, any value for the current consumption of the electric motor 4 can be identified with a corresponding angular position of the drive disk 6 between the initial position G and the end position E. As a result, the drive disk 6 can be moved into practically any desired angular position between the initial position G and the end position E, namely by detecting the current consumed by the electric motor 4 via the control unit 17, and stopping the supply of energy to the electric motor 4 when the desired angular position is reached.

[0044] In this process, it is of course possible to additionally take into account any lag of the electromotive drive due to mass inertia. This lag may correspond to a supplementary travel path or an additionally traversed angle of the drive disk 6 during its rotational movement about the axis 7, and can be taken into account by the control unit 17 in such a way that the electric motor 4 is stopped before the desired angular position is reachednamely reduced by an angular amount corresponding to the lag. If, for example, an angular position of 20? of the drive disk 6 is to be reached, with a lag of 5?, the control unit 17 ensures that the electric motor 4 is switched off when the angular position 15? is reached. In any case, the electromotive drive and/or its rotatable drive disk 6 can thereby be moved into the given, desired position. This is essential for the actuation of different functional positions within the motor vehicle lock in the examplefor example, in order to be able to achieve and implement functional positions such as theft-proof, child-proof or locked by means of the electromotive drive.

LIST OF REFERENCE SIGNS

[0045] 1, 2 Locking mechanism [0046] 3 Release lever [0047] 4 Electric motor [0048] 5 Output worm [0049] 6 Drive disk [0050] 7 Axis [0051] 8 Actuating contour [0052] 9 Spring or leg spring [0053] 9a Wound section [0054] 9b Drive leg [0055] 9 Extension arm [0056] 10 Contour [0057] 11 Pin [0058] 12 Lock housing [0059] 13 Stop [0060] 14 Stop [0061] 15 Latching contour [0062] 16 Cam [0063] 17 Control unit