ADJUSTING DRIVE WITH A SAFETY CLUTCH

Description

Field of invention

[0001] The present invention relates to an adjustment drive comprising an electric motor and a gearbox with a self-locking gear stage, in particular an adjustment drive in a motor vehicle. State of the art

[0002] It is known that motor vehicles use actuators to operate, for example, flaps or doors with the aid of an electric drive. Such actuators usually employ the smallest possible electric motors and often multi-stage gearboxes to transmit the torque. These multi-stage actuators often incorporate a self-locking gear stage, thus forming self-locking gearboxes.

[0003] To protect a self-locking gearbox from damage, it is often necessary to install a safety clutch that, in the event of excessive external torque, disconnects the self-locking gearbox stage from the externally applied torque. Especially with electric flaps, handles, and doors, a manual operation (tip-to-run) is often also provided, which subsequently activates the electric mechanism (gearbox). Typically, the manual movement is detected by partially disengaging the clutch in combination with an angle measurement and processed as a movement request to the motor.

[0004] The feel of a manually induced movement (tip to run) depends on the clutch torque, and it is difficult to achieve a consensus between haptics and the safety clutch for gearbox protection. Furthermore, when using a standard gearbox in different end applications, the safety-relevant component must be repeatedly adapted to the application in order to meet the haptic requirements.

[0005] From EP 3 483 477 A1, a drive arrangement for adjusting an aerodynamic flap on a vehicle is known, comprising an electric motor, a multi-stage transmission, an output shaft and at least two housing halves, wherein the transmission comprises spur gears and includes at least one self-locking transmission stage, wherein the self-locking transmission stage is neither the first nor the last transmission stage of the transmission. Summary of the invention

[0006] It is an object of the invention to improve an adjustment drive of the type mentioned in this respect and in particular to specify an adjustment drive comprising an electric motor and a gearbox with a self-locking gear stage, which enables a safety clutch and a desired haptic feel during manual operation (tip to run) and is flexibly adaptable to various requirements.

[0007] The problem is solved by an adjustment drive with the features according to claim 1.

[0008] The adjustment drive comprises an electric motor and a gearbox with a self-locking gear stage and with an output, wherein the gearbox includes a safety clutch which is designed to disconnect the self-locking gear stage from the external torque in the event of an excessively large external torque, i.e., introduced via the output, wherein the safety clutch has a free play, wherein at least one compressible and / or elastic and / or spring-loaded damping element is arranged in the free play, so that the haptics of an external movement request, i.e., introduced via the output, are co-determined by the damping element.

[0009] According to the invention, the adjustment drive has a safety clutch that can disengage a self-locking gear stage of the adjustment drive's gearbox from an excessively high external torque, i.e., open it in the event of a large applied torque. The safety clutch can be arranged between two gears of the adjustment drive's gearbox, in particular between two coaxial gears.

[0010] The actuator also features a free play mechanism to receive an external movement request. This request can be detected, activating the electric motor and thus the actuator. This functionality is also known as a "tip-to-run" mechanism.

[0011] According to the invention, a damping element is provided that dampens the free movement in the free passage, at least in sections. The damping element is a separate component. By using one or more such separate damping elements, the haptic feedback of a movement request can be selectively modified and thus adjusted.

[0012] By using a clutch with a damped free play integrated into the clutch, it is therefore possible to adjust the feel of the induced movement independently of the disengagement function of the safety clutch to a respective mechanism.

[0013] By using a separate damping element in the safety coupling, it is possible to implement various haptic variations without significant cost, as the safety-relevant function of the coupling is not affected by the haptic settings.

[0014] According to the invention, the safety clutch comprises a motor-side gear and an output-side gear, as well as a connecting element for connecting the motor-side gear to the output-side gear. In the closed state of the safety clutch, the connecting element has a positive locking connection to one of the two gears, either the motor-side gear or the output-side gear. The connecting element also includes a clearance and a damping element for the other gear, either the output-side gear or the motor-side gear. Both the safety clutch and the clearance with damping are thus designed to act between the connecting element and one of the gears.

[0015] Further developments of the invention are specified in the dependent claims, the description and the accompanying drawings.

[0016] Preferably, the adjustment drive comprises an angle measuring sensor and a control unit, wherein the control unit and the angle measuring sensor are configured such that the angle measuring sensor detects the external movement request and the control unit then activates the electric motor.

[0017] Preferably, the motor-side gear and the output-side gear are designed, at least axially in sections, as ring gears. The connecting element is then preferably arranged radially inside the motor-side gear and the output-side gear.

[0018] Preferably, the clearance is formed by the connecting element having radially outward projections that lie in corresponding recesses of the motor-side gear or the driven-side gear, wherein the recesses are wider than the projections, and / or vice versa, so that the connecting element has radially outward projections that lie around corresponding projections of the motor-side gear or the driven-side gear, wherein the recesses are wider than the projections. The connecting element can thus be, for example, star-shaped or sunburst-shaped. The connecting element can be arranged inside one of the two gears in such a way that limited backlash is present.

[0019] Preferably, at least one compressible and / or elastic and / or resilient damping element is arranged in the space between a protrusion and a recess. Particularly preferred are several compressible and / or elastic and / or resilient damping elements, each arranged in the spaces between a protrusion and a recess. Preferably, the damping element(s) have a U-shape and are arranged in a U-shape around the protrusions and / or in the recesses.

[0020] Preferably, the safety coupling uses coupling elements, in particular balls, for a positive-locking connection between the motor-side gear and the output-side gear, wherein, in the event of an excessively high external torque (i.e., applied via the output), the coupling elements are forced out of the positive-locking connection by the excessive external torque, thus disconnecting the self-locking gear stage from the external torque. The positive-locking connection between the motor-side gear and the output-side gear need not be located directly between the two gears, but can also be mediated by an intermediate connecting element.

[0021] The coupling elements, especially balls, can be pre-tensioned into the positive-locking connection, i.e., in the direction of closing the coupling, by means of spring elements.

[0022] Preferably, the coupling elements, in particular balls, are arranged essentially within the connecting element. When the coupling is closed, the coupling elements can be mounted in recesses of a surrounding gear, extending from the connecting element. Brief description of the drawings

[0023] The invention is described below by way of example with reference to the drawings. Fig. 1 is a three-dimensional representation of an adjustment drive according to the invention. Fig. 2 is a side sectional view of a part of the gearbox of an adjustment drive according to the invention. Fig. 1 Fig. 3 is a sectional view according to section BB of the Fig. 2 Fig. 4 is a sectional view according to section CC of the Fig. 2 . Detailed description of the invention

[0024] In Fig. 1An adjustment drive according to the invention is shown, together with a movement requirement 8, i.e. an external moment, which can be applied to the output 4 of the adjustment drive from the outside, for example via a handle.

[0025] The adjustment drive comprises an electric motor 1 and a gearbox 2. The gearbox 2 in turn comprises a self-locking gear stage 3, which can, for example, use a worm gear, an output 4, via which an element to be adjusted, such as a flap, door, etc., can be moved, and further gear stages that can be located between the self-locking gear stage 3 and the output 4.

[0026] The gearbox 2 includes a safety clutch 5, which is designed to disconnect the self-locking gearbox stage 3 from the external torque in the event of an excessively high external torque, i.e., torque applied via the output 4. The safety clutch 5 is located between two coaxial gears of the gearbox, namely between a motor-side gear 10 and an output-side gear 11.

[0027] The adjustment drive further comprises an angle measuring sensor 9 and a control unit (not shown), wherein the control unit and the angle measuring sensor 9 are configured such that the angle measuring sensor 9 detects the external movement request 8 and, if the movement request 8 is sufficiently strong and the angle change is sufficiently large, the control unit activates the electric motor 1.

[0028] The motor-side gear 10 and the output-side gear 11, together with the safety clutch 5 and the free gear 6, are in the Figs. 2 to 4 shown in more detail. The motor-side gear 10 and the output-side gear 11 are designed at least axially in sections as ring gears, so that the connecting element 12 can be arranged radially inside the motor-side gear 10 and the output-side gear 11.

[0029] The safety coupling 5 is, as in Fig. 2 shown, formed from a motor-side gear 10 and an output-side gear 11, as well as a connecting element 12 for connecting the motor-side gear 10 with the output-side gear 11.

[0030] In the closed state of the safety coupling 5, the connecting element 12 has a positive locking connection to one of the two gears 10, 11, namely in the embodiment shown, as in Fig. 3visible, to the motor-side gear 10.

[0031] The safety coupling 5 is used as described in Fig. 3 It is clearly visible that several widely spaced coupling elements 15, namely three balls in the illustrated case, form a positive-locking connection between the motor-side gear 10 and the output-side gear 11. In the event of an excessively large external torque, i.e., applied via the output 4, the coupling elements 15 are forced out of the positive-locking connection by the excessive external torque, thus opening the coupling and disconnecting the self-locking gear stage 3 from the external torque. The coupling elements 15, namely balls, are essentially arranged within the connecting element 12. The coupling elements 15, namely balls, are pre-tensioned into the positive-locking connection, i.e., to the closed state of the coupling, by means of U-shaped spring elements 16.

[0032] In Fig. 4It can be seen that the safety coupling 5 has a clearance 6 and that three compressible and / or elastic and / or spring-loaded damping elements 7 are arranged in the clearance 6. The damping element(s) 7 thus co-determines the haptic response to an external movement request 8, i.e., one introduced via the output 4. The damping elements 7 are distributed circumferentially around the connecting element 12 in at least some of the spaces within the clearance 6.

[0033] The connecting element 12 thus has the clearance 6 and the damping elements 7 to the output-side gear 11 - in the broad sense that the connecting element 12 significantly participates in these functions.

[0034] More precisely, the clearance 6 is formed by the connecting element 12 having radially outward projections 13, in this embodiment six of them, which lie in corresponding recesses 14 of the output-side gear 11. The recesses 14 are wider than the projections 13.

[0035] The compressible damping elements 7 are arranged in the spaces between each protrusion 13 and a recess 14, which are formed by the width of the recesses 14. Viewed axially towards the gears, the damping elements 7 each have a U-shape and lie in a U-shape between the protrusions 13 and the recesses 14.

[0036] To protect a self-locking gearbox from damage, a safety clutch 5 is installed. To detect a motion request 8 (tip to run), an angle measuring sensor 9, for example a potentiometer or Hall effect sensor, is provided between the self-locking gearbox stage 3 and the drive-side gear 10 of the clutch 5. To make the haptic requirements of the motion request (tip to run) adjustable, a release gear 6 with damping, namely with damping elements 7, is provided in the clutch 5.

[0037] The free play 6 allows the reversed gear on the output side 11 to rotate relative to the connecting element 12 without activating the disengagement mechanism of the safety clutch 5.

[0038] The damping element 7 is designed to be compressible or spring-like and generates a counter-moment that determines the haptics when the manually induced movement requirement 8 (tip to run) is applied, and also prevents loose play in the output.

[0039] If a person exerts a moment on the component connected to the output gear 4, for example a flap, a handle, or similar, this component yields according to the stiffness of the damping element 7 and the size of the clearance 6. The resulting rotation of the output can be detected via an angle sensor 9 and used as a trigger for an electric adjustment. Reference symbol list

[0040] 1 Electric motor 2 Gearbox 3 Self-locking gear stage 4 Output 5 Safety clutch 6 Free play 7 Damping element 8 Motion request 9 Angle measuring sensor 10 Motor-side gear 11 Output-side gear 12 Connecting element 13 Raise 14 Recess 15 Clutch element 16 Spring element

Claims

1. Adjusting drive comprising an electric motor (1) and a transmission (2) having a self-locking transmission stage (3) and having an output (4), wherein the transmission (2) comprises a safety clutch (5), which is configured, in the event of an excessive external torque, i.e. a torque introduced via the output (4), to separate the self-locking transmission stage (3) from the external torque, wherein the safety clutch (5) has a free travel (6), wherein at least one compressible and / or elastic and / or resilient damping element (7) is arranged in the free travel (6), with the result that the haptics of an external movement demand (8), i.e. a movement demand introduced via the output (4), are co-determined by the damping element (7) wherein the safety clutch (5) has a motor-side gearwheel (10) and an output-side gearwheel (11), characterized in that the safety clutch comprises a connection element (12) for connecting the motor-side gearwheel (10) to the output-side gearwheel (11), wherein the connection element (12) has a positive-locking connection to one of the two gearwheels (10, 11), the motor-side gearwheel (10) or the output-side gearwheel (11), in the closed state of the safety clutch (5), and wherein the connection element (12) has the free travel (6) and the damping element (7) for the other of the two gearwheels (11, 10), the output-side gearwheel (11) or the motor-side gearwheel (10).

2. Adjusting drive according to Claim 1, characterized in that the adjusting drive comprises an angle measuring sensor (9) and a control unit, wherein the control unit and the angle measuring sensor (9) are configured to ensure that the angle measuring sensor (9) detects the external movement demand (8), and the control unit then activates the electric motor (1).

3. Adjusting drive according to at least one of the preceding claims, characterized in that the motor-side gearwheel (10) and the output-side gearwheel (11) are embodied at least in some axial section or sections as ring gears, and in that the connection element (12) is arranged radially inside the motor-side gearwheel (10) and the output-side gearwheel (11).

4. Adjusting drive according to Claim 3, characterized in that the free travel (6) is formed by the fact that the connection element (12) has radially outer raised portions (13), which lie in corresponding recesses (14) in the motor-side gearwheel (10) or in the output-side gearwheel (11), wherein the recesses (14) are designed to be wider than the raised portions (13), and / or vice versa, such that the connection element (12) has radially outer recesses (14), which surround corresponding raised portions (13) on the motor-side gearwheel (10) or on the output-side gearwheel (11), wherein the recesses (14) are designed to be wider than the raised portions (13).

5. Adjusting drive according to Claim 4, characterized in that the at least one compressible and / or elastic and / or resilient damping element (7) is arranged in the interspace between a raised portion (13) and a recess (14), preferably a plurality of compressible and / or elastic and / or resilient damping elements (7) each being arranged in the interspaces between a raised portion (13) and a recess (14), preferably lying in a U shape around the raised portions (13) and / or in the recesses (14).

6. Adjusting drive according to at least one of the preceding claims, characterized in that the safety clutch (5) uses clutch elements (15), in particular balls, for a positive-locking connection between the motor-side gearwheel (10) and the output-side gearwheel (11), wherein, in the event of an excessive external torque, i.e. a torque introduced via the output (4), the clutch elements (15) are forced out of the positive-locking connection by the excessive torque, thus separating the self-locking transmission stage (3) from the external torque.

7. Adjusting drive according to Claim 6, characterized in that the clutch elements (15), in particular balls, are preloaded into the positive-locking connection by means of spring elements (16).

8. Adjusting drive according to at least one of Claims 1 to 5 and at least one of Claims 6 or 7, characterized in that the clutch elements (15), in particular balls, are arranged substantially in the connection element (12).