DE102023110938B3 - Actuator for a vehicle door or a vehicle flap with adjustable braking device - Google Patents

Abstract

The invention relates to an actuator for a vehicle door or a vehicle flap, comprising a housing with at least a first housing part (3), a drive unit arranged in the housing, wherein the drive unit comprises a drive shaft (9) rotatable about a drive axis, and a braking device (11) arranged in the housing for braking the drive shaft (9) or an actuating element driven by the drive shaft (9), wherein the braking device (11) comprises a first braking element (18) rotatably arranged in the housing and a second braking element arranged in a rotationally fixed manner in the housing, wherein the first braking element (18) and the second braking element interact to generate a braking torque, and wherein the braking torque generated by the braking device (11) can be adjusted by displacing an adjusting element (13) along an adjusting axis. To provide an actuator which comprises a braking device which can be reliably and flexibly optimized with regard to the braking torque provided and to specify a method for adjusting a braking torque generated by a braking device in an actuator which can be carried out simply and inexpensively even subsequently when the actuator is fully assembled, is achieved in that the adjusting element (13) is accessible for adjusting the braking torque via a closable opening (5) provided in the first housing part (3).

Description

The invention relates to an actuator for a vehicle door or a vehicle flap, comprising a housing with at least a first housing part, a drive unit arranged in the housing and a braking device arranged in the housing for braking the rotation of the drive shaft or of an actuating element driven by the drive shaft.

Actuators for vehicle doors or hatches are known in practice, which in normal operation enable a vehicle hatch or a vehicle door to be opened and closed between a closed and an open position. Such actuators often also have a braking device, which serves to quickly bring the adjustment of the vehicle door or vehicle hatch initiated by a drive unit arranged in the actuator to a standstill when the drive unit is switched off and which is generally also intended to relieve the load on the drive unit, since the braking device also takes on part of the weight of the vehicle door or vehicle hatch. The braking device is adjusted in terms of its braking torque depending on the installation situation of the actuator and the vehicle door or vehicle hatch to be driven, in order to ensure the desired effect of relieving the load on the drive unit in every intermediate position of the vehicle door or vehicle hatch. In addition, the braking device also serves as a continuously acting door holder, which ensures that even in the event of a failure of the drive unit, the vehicle door is not moved unbraked due to its own weight and can only be moved by applying appropriate manual force.

EP 3 649 376 B1 shows an actuator for a vehicle flap, wherein the actuator comprises a housing with a first housing part, wherein a drive unit designed as an electric motor with a drive shaft rotatable about a drive axis is arranged in the housing part. The drive shaft is coupled via a gear to a gear element designed as a spindle rod. The actuator further comprises a braking device arranged in the housing part for braking the rotation of the gear element driven by the drive shaft. The braking device comprises a first braking element coupled to the spindle rod in a rotationally fixed manner and a second braking element inserted in the housing part in a rotationally fixed manner, wherein a braking torque generated by the braking device occurs by displacement of the first braking element relative to the second braking element. The displacement takes place by means of an electromagnet, which can displace or preload the first braking element in the direction of the second braking element and can thereby cause both a complete release of the two braking elements and an increase or decrease of the braking torque by appropriate control of the electromagnet.

EN 20 2018 101 761 U1 shows an actuator for a pivotable vehicle flap or a vehicle door, comprising a housing with at least a first housing part, a drive unit arranged in the first housing part with a drive shaft that can rotate about a drive axis, and a braking device arranged in the housing for braking the rotation of a gear element designed as a spindle rod and driven by the drive shaft. The braking device is designed as a multi-disk brake and comprises a preloading means designed as a compression spring, which rests with a first end on a stop part screwed into a brake housing part, which is ring-shaped and has an external thread that engages with an internal thread provided on an inner diameter of the brake housing part. A second end of the preloading means rests on a brake element, so that the preloading means preloads this brake element onto another brake element and thus determines the braking torque generated by the braking device. The braking device is adjustable by displacing the stop part that serves as an adjustment element, by screwing the stop part more or less far into the brake housing part.

EN 10 2019 105 842 A1 shows an actuator for a vehicle flap, comprising a housing with a housing part, wherein a drive unit with a drive shaft rotatable about a drive axis is arranged in the housing part. The actuator further comprises a braking device arranged in the housing part for braking the drive shaft, wherein the braking device has a first braking element rotatably arranged in the housing and a second braking element arranged in a rotationally fixed manner in the housing, which interact frictionally to generate a braking torque. The braking torque can be adjusted by moving an adjusting element of an adjusting device along an adjusting axis. The adjusting element is designed as a screw and is inserted into an opening provided in the housing part, wherein the adjustment element can be moved along the adjusting axis by a screwing movement.

EN 10 2022 116 871 A1 shows an actuator for a vehicle door or a vehicle flap, comprising a housing with a first housing part and a second housing part. A free end of a drive shaft that can rotate about a drive axis is arranged in the housing, the drive shaft being coupled to a transmission shaft via a gear. To brake the transmission shaft driven by the drive shaft, the actuator comprises a braking device that includes a braking element that is preloaded onto the transmission shaft via a spring. The braking element is rotationally fixed relative to the housing and can also be displaced radially in the direction of the transmission shaft. To adjust the preload of the spring and thus the braking torque, an adjusting element designed as a screw can be adjusted in an opening in the housing part that is provided with an internal thread, the spring being clamped between the adjusting element and the braking element.

EN 10 2018 131 966 A1 shows an actuator for a vehicle flap, comprising a housing and a drive unit, wherein the drive unit comprises a drive shaft rotatable about a drive axis. The actuator further comprises a braking device for braking a rotation of a spindle rod rotatably arranged in the housing, wherein the braking device has a first brake disc coupled to the spindle rod in a rotationally fixed manner and a brake pad coupled to the housing in a rotationally fixed manner, which cooperates with the brake disc to generate a braking torque. The actuator further comprises an adjusting device for adjusting the braking torque of the braking device. The adjusting device comprises an adjusting element which is designed as a screw, wherein a coil spring is arranged between the adjusting element and the brake pad, so that the braking torque can be adjusted by a screwing movement of the adjusting element and the associated displacement of the adjusting element along an adjusting axis.

EN 10 2017 107 839 A1 shows an actuator for a vehicle flap, comprising a housing part, a drive unit with a drive shaft that can be rotated about a drive axis and a braking device for braking a spindle driven by the drive unit. The braking device comprises a friction lever that is in frictional contact with the spindle and thus generates a braking torque. The preload of the friction lever against the spindle is provided by a spring, with the preload force being adjustable via a screw.

It is the object of the invention to create an actuator which comprises a braking device which can be reliably and flexibly optimized with regard to the braking torque provided. Furthermore, it is the object of the invention to provide a method for adjusting a braking torque generated by a braking device in an actuator which can be carried out simply and inexpensively even subsequently when the actuator is fully assembled.

This object is achieved according to the invention by an actuator having the features of claim 1 or a method according to claim 10.

According to one aspect of the invention, an actuator for a vehicle door or a vehicle flap is created, comprising a housing with at least a first housing part and a drive unit arranged in the housing, wherein the drive unit comprises a drive shaft rotatable about a drive axis. The actuator further comprises a braking device arranged in the housing for braking the drive shaft or an actuating element driven by the drive shaft, wherein the braking device comprises a first braking element rotatably arranged in the housing and a second braking element arranged in a rotationally fixed manner in the housing, wherein the first braking element and the second braking element interact to generate a braking torque, wherein the braking torque generated by the braking device can be adjusted by moving an adjusting element along an adjusting axis and the adjusting element is accessible via an opening provided in the first housing part for adjusting the braking torque. The actuator according to the invention is characterized in that the braking device is designed as a hysteresis brake, with the first braking element being designed as a multi-pole permanent magnet which is coupled in a rotationally fixed manner to the drive shaft or to a gear element coupled to the actuator, and the second braking element being designed as a film or a layer of a hysteresis material which is connected to the adjustment element. The braking device is advantageously particularly compact and does not require an external power source, since the variable magnetic field required for the braking effect is already generated by the rotation of the drive shaft or the gear element itself. The braking torque can advantageously be subsequently adjusted in the actuator once it has been fully assembled. In particular, the subsequent adjustment of the braking device means that the braking torques required depending on the vehicle and the specifications of the slope can be adjusted, so that only one or a few variants of a braking device or actuator are required. Another advantage This simplifies the control of the actuator and reduces the actuator's power consumption, allowing more precise adjustment depending on the required holding force for the vehicle flap or vehicle door. In addition, the drive unit requires fewer reserves, as the friction-related tolerances of the individual components of the actuator can be compensated for by readjusting the braking torque.

In a preferred embodiment, the adjustment element can be moved by a tool element. The opening is expediently designed to accommodate the tool element. The tool element advantageously has an end section which is intended for coupling with a manually or motor-driven tool. The tool element can particularly preferably be moved or rotated via the end section using preferably motor-driven tools such as an electric screwdriver. The adjustment element can advantageously be moved particularly conveniently by placing this tool on the tool element and actuating the tool element. When the tool element is inserted, the end section protrudes over an upper edge of the opening so that it is accessible for coupling with the tool.

The adjustment element can particularly preferably be displaced along the adjustment axis by rotating it around the adjustment axis. The adjustment element advantageously has a coupling section which is provided for coupling with a counter-coupling section arranged on the tool element. The coupling section is expediently arranged in the area of the opening so that the coupling section can be coupled for coupling with the tool element. An external gear is particularly preferably provided in the coupling section. Further preferably, an external thread is provided in the counter-coupling section of the tool element, which can be brought into threaded engagement with the external gear.

Advantageously, the adjustment element can be moved particularly precisely along the adjustment axis by making the pitches of the threads sufficiently small.

According to a further aspect of the invention, a method is provided for adjusting a braking torque generated by a braking device in an actuator as described above, wherein the method comprises, in a first method step, determining an axial force required during an extension and retraction movement of an actuating element provided on the actuator. In a second method step, the measured axial force is compared with a predetermined target value. In a third method step, a braking torque generated by the braking device is adjusted, wherein the third method step comprises inserting a tool element into the opening provided in the first housing part while coupling a coupling section of the adjusting element to a counter-coupling section of the tool element. The third method step further comprises rotating the tool element about a rotation axis, whereby the rotation of the tool element leads to a displacement of the adjustment element along an adjustment axis in the housing of the actuator, whereby the adjustment axis and rotation axis are perpendicular to one another and the tool element is actuated until the braking torque generated by the braking device corresponds to a value specified by the target value of the axial force. The braking torque can advantageously be adjusted when the actuator is already fully assembled, so that the friction tolerances that occur within the actuator can easily be compensated for later by adjusting the braking device.

Further advantages, properties, features and developments of the claimed invention emerge from the following description of a preferred embodiment and from the dependent claims.

• 1 zeigt ein bevorzugtes Ausführungsbeispiel eines erfindungsgemäßen Stellantriebes in einer Seitenansicht.
• 2 zeigt den Stellantrieb 1 mit entferntem erstem Gehäuseteil 3.
• 3 zeigt eine vergrößerte Ansicht des Stellantriebs 1 im Bereich der Bremsvorrichtung 11 mit verlagertem Einstellelement 13.
• 4 zeigt eine Draufsicht auf den in 1 markierten Querschnitt A-A.
• 5 zeigt eine Draufsicht auf den in 1 markierten Querschnitt B-B.

The invention is explained in more detail below with reference to the accompanying drawings.

• 1 shows a preferred embodiment of an actuator according to the invention in a side view.
• 2 shows the actuator 1 with the first housing part 3 removed.
• 3 shows an enlarged view of the actuator 1 in the area of the braking device 11 with displaced adjustment element 13.
• 4 shows a top view of the 1 marked cross section AA.
• 5 shows a top view of the 1 marked cross section BB.

1 shows a preferred embodiment of an actuator according to the invention in a side view. The actuator 1 comprises a housing 2, wherein the housing 2 comprises a first housing part 3. The housing 2 further comprises a second housing part 4, wherein the first housing part 3 is arranged on the second housing part 4 and is attached. The first housing part 3 has a tightly sealable opening 5 through which a braking device accommodated in the housing 2, not visible here, can be adjusted in terms of its torque, which is explained in more detail below. The housing 2 is firmly connected to a vehicle door VF, shown here in dashed lines, via rivet pins 6. To drive a pivoting movement of the vehicle door VF, the actuator has an actuating element 7 which can be extended telescopically from the housing 2 and which is connected in an articulated manner to the vehicle body VB. As a result, an opening movement of the vehicle door VF is driven when the actuating element 7 is extended from the housing 2.

2 shows the actuator 1 with the first housing part 3 removed, so that the components of the actuator 1 arranged below the first housing part 3 are now visible. As can be seen, the actuator 1 comprises a drive unit 8 arranged lying in the housing 2 or in the second housing part 4, wherein the drive unit 8 in the present embodiment is designed as an electric motor and drives a linear movement of the actuating element 7 via a spindle gear not visible here. At a first end 8a of the drive unit 8, a drive shaft 9 designed as a worm shaft is provided, which can be coupled to the spindle gear not visible here, wherein the spindle gear comprises a first gear element designed as a spindle rod and a spindle nut threadedly engaged with the spindle rod. The spindle nut is thereby axially displaced within the housing 2, wherein the spindle nut is coupled to the actuating element 7, so that the actuating element 7 is displaced together with the spindle nut. The drive shaft 9 advantageously has a worm thread 10 at the first end 9a shown here.

A braking device 11 is arranged at a second end 8b of the drive unit 8 opposite the first end 8a, which is intended to brake the rotary movement of the drive shaft 9 about the drive axis A. The braking device 11 can be adjusted with respect to a braking torque acting on the drive unit 8 via a tool element 12, as explained in more detail below.

In the embodiment shown here, the braking device 11 is designed as a hysteresis brake. In contrast to an eddy current brake, a braking torque is advantageously provided by the braking device 11 regardless of the speed of the drive shaft 9 of the drive unit 8, so that it is particularly easy to adjust the braking torque to optimize the driving force to be applied by the drive unit 8 and the holding force required to hold the vehicle door on steep slopes between the fully open position and the fully closed position. In particular, the drive unit 8 is relieved by the braking device 11, since the braking device 11 applies the holding forces required to hold the vehicle body of the vehicle door in an intermediate position and thus reduces the power consumption of the drive unit 8.

The braking device 11 comprises an adjusting element 13 which has an external thread 14 which is in threaded engagement with an internal thread 15 provided in the housing 2. In the state shown here, the adjusting element 13 is displaced in the direction of the drive unit 8 so that the internal thread 15 can be seen. As explained in more detail below, the position of the adjusting element 13 corresponds to a maximum braking torque which acts on the drive shaft 9 through the braking device 11. The adjusting element 13 also has a coupling section 16 arranged adjacent to the external thread 14, which is intended for coupling with a counter-coupling section 17 provided on the tool element 12.

3 shows an enlarged view in the area of the braking device 11. Compared to the 2 In the state shown, the adjusting element 13 was displaced away from the drive unit 8 by rotation about an adjusting axis S along the adjusting axis S. Due to this, it can be seen in this view that the braking device 11 is coupled to a second end 9b of the drive shaft 9, so that the braking device 11 generates a braking torque on the drive shaft 9. As explained below, due to the displacement of the adjusting element 13 along the adjusting axis S, a reduced braking torque is achieved compared to the state from 2 generated.

The rotation of the adjustment element 13 about the adjustment axis S was driven by rotation of the tool element 12 about a rotation axis D, whereby the coupling section 16 of the adjustment element 13 and the counter-coupling section 17 of the tool element 12 are in threaded engagement. In the embodiment shown here, the adjustment axis S of the adjustment element 13 and the rotation axis D of the tool element 12 are perpendicular to each other. The displacement of the adjustment element 13 along the adjustment axis S occurs due to the fact that the external thread 14 of the adjustment element 13 is in threaded engagement with the internal thread 15 of the housing 2. The internal thread 15 is half in the first housing part 3 and the second housing part 4 so that a circumferential internal thread 15 is formed.

4 shows a top view of the 1 marked cross-section AA. The cross-section runs perpendicular to the adjusting axis S or the drive axis A and runs through the opening 5 with the tool element 12 accommodated therein. In this view it can be seen that the tool element 12 has a bearing section 12a at an upper end with an outer diameter that corresponds to an inner diameter of the opening 5. The tool element 12, which can be rotated about the axis of rotation D, is advantageously guided through the opening 5 and supported radially. Above the bearing section 12a there is an end section 12b which is polygonal in cross-section and which can be coupled in a rotationally fixed manner to a corresponding tool, for example an electrically driven screwdriver, in order to rotate the tool element 12 about its axis of rotation D.

The tool element 12 has a cylindrical extension 12c at a lower end, which is accommodated in a hollow cylindrical bearing point 4a provided in the second housing part 4. The lower end of the tool element 12 is also advantageously supported axially and radially, so that it is ensured that the counter-coupling section 17 arranged between the bearing section 12a and the cylindrical extension 12c remains in threaded engagement with the coupling section 16 provided on the adjustment element 13 while the tool element 12 is rotated about the axis of rotation D. The adjustment element 13 rotates radially around a multi-pole permanent magnet 18 which is connected to the drive shaft 9 in a rotationally fixed manner and which is rotated accordingly with the drive shaft 9 about the drive axis A. The multi-pole permanent magnet 18 forms a first braking element of the braking device 11 designed as a hysteresis brake.

5 shows a top view of the 1 marked cross section BB. The cross section runs parallel to the longitudinal extent of the housing 2 of the actuator 1. In this view it can be seen that the adjustment element 13 has a film 19 made of a hysteresis material on an inner side 13a facing the permanent magnet 18, which runs parallel to a side surface 18a of the permanent magnet 18, which is spaced from the side surface 18a of the permanent magnet 18 by an air gap G. The adjustment element 13 is designed as a hollow cylinder in the embodiment shown here, which is in threaded engagement via the external thread 14 with the internal thread 15 provided on both the first housing part 3 and the second housing part 4.

In the state shown here, the adjustment element 13 has been completely displaced downwards, so that the adjustment element 13 is close to a bottom surface B provided by the first housing part 3 and the second housing part 4. The bottom surface B also serves as a stop surface which limits the displacement of the adjustment element 13. It can also be seen that the axial overlap between the film 19 and the permanent magnet 18 corresponds to slightly less than half of the respective total longitudinal extent of the film 19 or the permanent magnet 18. As a result, the braking torque generated on the drive shaft 9 by the braking device 11 designed as a hysteresis brake is reduced compared to a situation in which the film 19 and the permanent magnet 18 overlap more or even completely axially. Accordingly, by rotating the tool element 12 about the axis of rotation D and the associated displacement of the adjusting element 13, the braking torque generated by the braking device 11 can be continuously increased or reduced or adjusted to a required value.

Claims (10)

Actuator (1) for a vehicle door or a vehicle flap (VF), comprising a housing (2) with at least a first housing part (3), a drive unit (8) arranged in the housing (2), wherein the drive unit (8) comprises a drive shaft (9) rotatable about a drive axis (A), and a braking device (11) arranged in the housing (2) for braking the drive shaft (9) or an actuating element (7) driven by the drive shaft (9), wherein the braking device (11) comprises a first braking element (18) rotatably arranged in the housing (2) and a second braking element (19) arranged in a rotationally fixed manner in the housing, wherein the first braking element (18) and the second braking element (19) cooperate to generate a braking torque, and wherein the braking torque generated by the braking device (11) can be adjusted by displacing an adjusting element (13) along an adjusting axis (S), wherein the adjusting element (13) can be adjusted via a lockable locking mechanism provided in the first housing part (3). Opening (5) is accessible for adjusting the braking torque, characterized in that the braking device (11) is designed as a hysteresis brake, wherein the first braking element (18) is designed as a multi-pole permanent magnet, which is rotationally fixed to the drive shaft (9) or to a gear element coupled to the adjusting element (7) and the second braking element (19) is designed as a film or a layer of a hysteresis material which is connected to the adjusting element (13). Actuator (1) after Claim 1 , characterized in that the adjusting element (13) can be displaced by a tool element (12). Actuator (1) after Claim 2 , characterized in that the opening (5) is designed to receive the tool element (12). Actuator (1) after Claim 3 , characterized in that the tool element (12) has an end portion (12b) which is intended for coupling to a manually or motor-driven tool. Actuator (1) after Claim 4 , characterized in that the end portion (12b) projects beyond an edge of the opening (5). Actuator (1) according to one of the preceding claims, characterized in that the adjusting element (13) is displaceable along the adjusting axis (S) by rotation about the adjusting axis (S). Actuator (1) according to one of the preceding claims, insofar as Claim 2 referred back, characterized in that the adjusting element (13) has a coupling section (16) which is intended for coupling with a counter-coupling section (17) provided on the tool element (12). Actuator (1) after Claim 7 , characterized in that the coupling section (16) is arranged in the region of the opening (5), so that the coupling section (16) can be coupled to the tool element (12). Actuator (1) after Claim 7 or 8th , characterized in that an external gear is provided in the coupling section (16). Method for setting a braking torque generated by the braking device (11) in an actuator (1) according to one of the preceding claims, comprising determining an axial force required during an extension and retraction movement of an adjusting element (7) provided on the actuator (1), comparing the measured axial force with a predetermined target value, setting a braking torque generated by the braking device, comprising inserting a tool element (12) into the opening (5) provided in the first housing part (3) while coupling a coupling section (16) of the adjusting element (13) with a counter-coupling section (17) of the tool element (12), rotating the tool element (12) about an axis of rotation (D), wherein the rotation of the tool element (12) leads to a displacement of the adjusting element (13) along an adjusting axis (S) in the housing (2) of the actuator (1), wherein the adjusting axis (S) and the axis of rotation (D) are perpendicular to each other and the tool element (12) is actuated until the braking torque generated by the braking device (11) corresponds to a value predetermined by the target value of the axial force.

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