BRAKE SYSTEM

Description

[0001] The invention relates to a braking device for a drivable part according to the preamble of an independent claim, in particular for use for a vehicle door or a vehicle flap, in particular in an automobile.

[0002] Drives are known in practice that move drivable components, particularly around a pivot axis. In this case, an electric motor delivers a sufficiently high torque to overcome the load resulting from the mass of the components. For example, in vehicle lids such as trunk lids, the drive moves them from a closed position to an open position and back.

[0003] Automatic opening, closing, holding, and braking of a vehicle's tailgate or door using electric drives not only increases convenience but also offers greater security. For example, tailgates for loading activities can be opened and closed contactlessly using a sensor and a simple foot gesture. On the other hand, electric drives for vehicle doors or tailgates offer increased theft protection when integrated into the vehicle's central locking system.

[0004] Furthermore, drive-controlled vehicle doors or hatches can detect an obstacle, such as a hand, between a vehicle door or hatch and a vehicle door frame via a sensor. Consequently, the vehicle door or hatch is decelerated via the respective drive, thus preventing injuries from a hand or other body part being trapped. Similarly, other drive-controlled components can detect an impending collision, for example, with a wall or another parked vehicle, via a sensor, thus preventing damage during the opening process of the vehicle door or hatch by decelerating and holding the vehicle door or hatch.

[0005] Furthermore, electric drives must be designed to open and / or close the vehicle door or tailgate in the event of a tilted vehicle, by delivering a sufficiently high motor torque. Furthermore, it must be ensured that the electric drives are capable of holding the open vehicle door or tailgate even when the vehicle is tilted.

[0006] When transporting bulky goods stored in a trunk, it is also advantageous to lock the tailgate in a defined position, preventing unwanted automatic opening due to vibrations. A disadvantage of conventional electric drives is that they require continuous power to hold the vehicle door or tailgate in an intermediate position. This leads to high energy consumption and unnecessary heating of the drives, as well as a shortened service life of the components.

[0007] Furthermore, the known drives often have slip clutches so that in the event of a malfunction, the part to be driven can be opened or closed manually.

[0008] In order for vehicle doors and vehicle hatches to meet the above conditions, electric drives are preferably provided in combination with a braking device in order to open, close, hold or brake a vehicle door or vehicle hatch in a controlled manner during a movement of the vehicle door or vehicle hatch.

[0009] DE 20 2019 100 595 U1 discloses a braking device for a drivable part, in particular for use in a vehicle door or a vehicle tailgate, in particular in an automobile. The braking device comprises a drivable loading device that can be brought into radial contact with the drivable part, having a first holding position and a second release position. On the one hand, in the holding position, at least one braking element frictionally abuts a radial periphery of the drivable part, so that the drivable part is secured against rotation with a presettable force. On the other hand, in the release position, the braking element is spaced from the radial periphery of the drivable part, so that freewheeling of the drivable part is permitted. The loading device is adjustable between the holding position and the release position by means of a drive.A disadvantage of the known braking device is that braking occurs solely through frictional contact between at least one braking element and the drivable part. Accordingly, a precisely defined braking torque of the braking device on a drivable part can neither be precisely adjusted nor delivered.

[0010] US 2021 / 198935 A1 discloses a braking device, particularly for use on a vehicle door or a vehicle tailgate, particularly in an automobile. The braking device comprises a drivable loading device with a first holding position and a second release position, wherein the loading device is adjustable between the holding position and the release position by means of a drive.

[0011] The object of the invention is to create a braking device that is reliable and delivers an exact braking torque.

[0012] This object is achieved according to the invention by a braking device having the features of independent claim 1.

[0013] According to the invention, a braking device for a drivable part is provided, in particular for use in a vehicle door or a vehicle lid, in particular in an automobile. The braking device comprises a drivable loading device that can be brought into radial contact with the drivable part, having a first holding position and a second release position. In the holding position, at least one braking element frictionally abuts a radial circumference of the drivable part and secures the drivable part against rotation with a presettable force. In the release position, the braking element is spaced from the radial circumference of the drivable part and allows freewheeling of the drivable part. The loading device is adjustable between the holding position and the release position by means of a drive. The braking device is characterized in that the drivable part is coupled to at least one permanent brake.Advantageously, a combination of a permanent brake and a switchable brake provides both a short reaction time of the braking device and a precisely defined braking torque. The permanent brake offers the advantage of being able to be precisely preset with regard to the desired braking torque. The switchable brake has a very short reaction time, so that this combination advantageously provides the above-mentioned braking device with both a precisely presettable braking torque through the permanent brake and a very fast reaction time of the load device.

[0014] According to the invention, the braking element of the loading device can be brought into radial contact with a housing section of the permanent brake. Advantageously, a housing section of the permanent brake is arranged at the same height as the braking element of the loading device. As a result, the braking element of the loading device can radially grip an outer surface of the housing section of the permanent brake, so that a braking force acts on the housing section, thereby locking the housing section of the permanent brake.

[0015] According to the invention, a braking torque from the permanent brake acts on the drivable part in the stop position. Advantageously, a precisely defined braking torque is delivered to the drivable part, which is preset in advance with respect to the permanent brake. Furthermore, the braking torque of the permanent brake can be individually preset depending on the vehicle model, ensuring versatile application possibilities with regard to the weight of a vehicle door or vehicle tailgate.

[0016] According to the invention, the drivable part is freely rotatable in the release position with the permanent brake. Advantageously, in the release position, no braking occurs due to the permanent brake of the drivable part, thus saving energy and preventing unnecessary wear on components, thereby increasing their service life. Furthermore, disturbing noises, such as friction noises, are avoided during operation of a vehicle door or vehicle tailgate.

[0017] The drivable part preferably comprises a shaft or a spindle. The shaft or spindle is primarily used to adjust vehicle doors or vehicle tailgates using, for example, an electric drive and a corresponding gear configuration. Advantageously, the braking effect of the permanent brake on the drivable part is delivered exclusively in the holding position, so that in the release position, the permanent brake can be freely rotated together with the shaft or spindle of the drivable part to which the permanent brake is arranged or coupled. Advantageously, the braking torque with respect to the permanent brake is precisely adjustable, so that when the braking device is activated, a precisely defined and time-controlled or regulated braking torque is delivered.

[0018] Preferably, the braking torque of the permanent brake can be adjusted once. The braking torque of the permanent brake is expediently between 0.2 Nm and 3 Nm, preferably between 0.5 Nm and 2 Nm, and particularly preferably 1 Nm. Advantageously, the desired braking torque is precisely preset during production of the permanent brake. Furthermore, it is advantageous to preset the braking torque only once, so that the permanent brake is ready for operation after the braking torque has been preset.

[0019] Advantageously, the braking torque of the loading device is at least twice as high as the braking torque of the permanent brake. This advantageously allows the permanent brake to be gripped and held by at least one braking element, preventing the locked housing section of the permanent brake from slipping in the holding position.

[0020] Preferably, the drivable part is designed to rotate in the manner of a slip clutch when the braking torque of the permanent brake is exceeded in the stop position. If the drivable part coupled to the permanent brake has a higher torque than the braking torque of the permanent brake, the drivable part slips relative to the permanent brake. Thus, thanks to an integrated slip clutch, the vehicle door or tailgate can advantageously be manually adjusted in the event of a malfunction or defect.

[0021] In the holding position, the housing section of the permanent brake, which is locked by the brake element, is conveniently held in position in a non-rotatable manner in the event of the driven part spinning. This advantageously ensures that only the preset braking torque of the permanent brake is delivered to the driven part.

[0022] The loading device is expediently switchable. A switchable loading device has the advantage that it can be activated or deactivated only when needed, whereby the loading device advantageously has a very short reaction time. Furthermore, a switchable loading device can advantageously be computer-controlled and coupled with appropriate sensors. In the event of a sudden gust of wind, for example, the corresponding sensors can register that the respective vehicle door or hatch is opening or closing too quickly. This information is then processed by a computer, which uses the braking device to decelerate the affected vehicle door or hatch.

[0023] Preferably, the reaction time of the loading device for adjusting the braking element is between 30 and 100 milliseconds, preferably between 40 and 80 milliseconds, and particularly preferably 60 milliseconds. A fast reaction time of the loading device advantageously increases the operational reliability of the driven part.

[0024] According to a preferred embodiment, the drivable part is arranged coaxially with the permanent brake. This advantageously connects the drivable part to the permanent brake in a space-saving manner. Furthermore, the coaxial design ensures that a reliable braking torque is always transmitted from the permanent brake to the drivable part.

[0025] According to a further preferred embodiment, the driven part is arranged concentrically with respect to the permanent brake. This offers the advantage that coupled components exhibit very good concentricity. The corresponding components are thus aligned, straight, centered, and not offset from one another. This ensures a certain smoothness of the moving components, resulting in an extended service life and advantageously low-noise operation.

[0026] The permanent brake is preferably designed as a permanent magnet brake and / or as a permanent spring-loaded brake. Various embodiments of a permanent brake exist. The advantage of a permanent magnet brake is that it can be switched on and controlled, whereas a permanent spring-loaded brake is preloaded by a spring that continuously delivers a preset braking torque. The advantage of a permanent spring-loaded brake is, among other things, its uncomplicated design and its fail-safe operation, which contributes to very high operational reliability.

[0027] The permanent brake is preferably designed as a combination of a permanent magnet brake and a permanent spring-loaded brake. This advantageously allows the use of a switchable permanent brake that continuously delivers a preset braking torque via the spring in a de-energized state. This embodiment of a permanent brake is advantageously fail-safe, as it delivers braking torque even when de-energized. Accordingly, the above combination offers the advantage of switchability on the one hand, and very high operational reliability on the other.

[0028] Overall, it is advantageous that, in the release position, the radial distance between the housing section of the permanent brake and the brake element is between 0.2 and 1.2 millimeters, preferably between 0.4 and 0.8 millimeters, and particularly preferably 0.5 millimeters. The advantage of the small distance of 0.5 millimeters results in the fast response time of the loading device, since only a short distance relative to the brake element must be covered to contact the housing section of the permanent brake or to release it accordingly.

[0029] A brake contact surface of the brake element is expediently designed to be concave. The concave shape of the brake contact surface of the brake element advantageously allows the brake element to conform evenly to an outer surface of the housing section of the permanent brake during a transition from the release position to the hold position, thereby locking it in place. This results in optimal braking performance, as the entire brake contact surface of the brake element is utilized. According to a further embodiment, the concave brake contact surface of the brake element has a rough friction surface or a rubberized coating, thus achieving an even greater braking performance.

[0030] According to a preferred embodiment, the permanent brake has a cylindrical, conical, ellipsoidal, or hourglass-shaped outer geometry. A rotationally symmetrical outer geometry of the permanent brake advantageously provides even load distribution, resulting in smooth running and excellent concentricity of the rotating permanent brake, as, for example, imbalance is avoided. Furthermore, this allows the permanent brake to be contacted by the brake element without jamming, and a high braking effect is achieved.

[0031] According to a preferred embodiment, the drive is a direct current motor. DC motors advantageously exhibit very high acceleration, while also having a wide speed range and a long service life. Furthermore, DC motors are compact and small, and they are also ideal for precise positioning drives. Therefore, a direct current motor is preferably used for adjusting the braking element of the braking device.

[0032] Conveniently, the drive comprises a shaft that can rotate in two directions. The drive shaft can advantageously rotate either clockwise or counterclockwise.

[0033] According to one embodiment, the shaft comprises a threaded portion that engages a nut, wherein the nut is axially displaceable with respect to the drive between the first holding position and the second release position. Advantageously, the drive shaft, with its integrated threaded portion, directly drives a nut, so that, due to the reversibility of the shaft's direction of rotation, the nut can be displaced along a shaft axis, thereby enabling a holding position or a release position of the braking device to be set. Furthermore, no additional components designed as coupling parts are required to connect the shaft to the nut.

[0034] According to a further alternative embodiment, the drive is a linear motor or a linear actuator or an electromagnetic actuator. In this case, the linear motor or the linear actuator or the electromagnetic actuator preferably comprises a housing and an actuator, wherein the actuator is axially displaceable with respect to a housing between the first holding position and the second release position. Advantageously, the braking device can be equipped with a linear motor or a linear actuator, which facilitates assembly since, for example, fewer components are required for the braking device. When an electromagnetic actuator is used as the drive, an armature assumes a specific position depending on the current supplied to an integrated electromagnetic coil. The armature can be moved back and forth linearly and has at least two stop positions.Advantageously, it is possible to use different drives in the above braking device, so that the possible applications of the braking device are variable with regard to the installation space as well as the desired braking torque or the general movement sequence.

[0035] According to a preferred embodiment, the drivable loading device comprises a first brake member and a second brake member, which each in the holding position frictionally bear against a radial circumference of the drivable part and secure the drivable part against rotation with a presettable force and in the release position are spaced from the radial circumference of the drivable part and allow freewheeling of the drivable part, wherein the first brake member is articulated about a first pivot joint with a first pivot axis, wherein the second brake member is articulated about a second pivot joint with a second pivot axis, and wherein the drivable part is arranged between the drive of the loading device and the two pivot axes.

[0036] Advantageously, both the driven part and the permanent brake are arranged between the drive and the two pivot axes, allowing the first and second brake elements to grip a housing section of the permanent brake in a pincer-like manner, providing very high braking force thanks to the optimized lever arm lengths. This arrangement advantageously offers a compact design for the braking device and ensures a very high braking effect and a very fast response time for both brake elements.

[0037] According to an aspect not according to the invention, a braking device for a drivable part is provided, in particular for use in a vehicle door or a vehicle lid, in particular in an automobile.The braking device comprises a drivable loading device which can be brought into radial contact with the drivable part, having a first holding position and a second release position, wherein in the holding position a first braking member and a second braking member frictionally bear against a radial circumference of the drivable part and secure the drivable part against rotation with a pre-adjustable force, wherein in the release position the first and the second braking member are spaced from the radial circumference of the drivable part and allow freewheeling of the drivable part, wherein the loading device is adjustable between the holding position and the release position by means of a drive, wherein the first braking member is articulatedly pivotable about a first pivot joint having a first pivot axis, wherein the second braking member is articulatedly pivotable about a second pivot joint having a second pivot axis.In the braking device, the drivable part is arranged between the drive of the loading device and the two swivel axes.

[0038] Advantageously, the driven part is arranged between the drive and the two pivot axes, allowing the first and second brake elements to grip the driven part in a pincer-like manner with a very high braking force thanks to the optimized lever arm lengths. This arrangement advantageously offers a compact design of the braking device and ensures a very high braking effect and a very fast response time for both brake elements.

[0039] Conveniently, the drive comprises a motor with a rotatable shaft. Furthermore, the rotatable shaft has a coupling part that can be engaged with a guide part, whereby the guide part can be axially displaced when the shaft is rotated.

[0040] Preferably, the coupling part is designed as a cylindrical threaded section. Furthermore, the guide part is designed as an internally toothed nut, which is displaced axially relative to the motor upon rotation of the threaded section.

[0041] This advantageously creates a positive connection between the coupling part and the guide part, after which the guide part can be driven by the coupling part, enabling a controlled pivoting movement of the two brake elements. This pivoting movement results in either a holding position or a release position of the loading device.

[0042] The first brake element expediently contains a first housing for accommodating the motor. Furthermore, the second brake element preferably contains a second housing for accommodating the guide part. Advantageously, the motor and at least one guide part are already integrated into the two brake elements within the respective housing, thus providing a compact braking device.

[0043] Preferably, the first brake member has a first end and a second end, wherein the first pivot joint is arranged at the first end of the first brake member, and wherein the first housing is arranged at the second end of the first brake member.

[0044] Preferably, the second brake member has a first end and a second end, wherein the second pivot joint is arranged at the first end of the second brake member, and wherein the second housing is arranged at the second end of the second brake member.

[0045] Advantageously, both brake elements each have a pivot joint, and both brake elements each have a housing. Accordingly, the first and second brake elements are optimally utilized in terms of installation space, resulting in a compact braking system. Furthermore, the direct installation of a motor in one of the protruding brake elements results in an increased reaction speed of the braking system, thus ensuring the desired braking effect and the safety of the braking system.

[0046] According to a further development, the first housing and the second housing each comprise a removable cover. Advantageously, the interior of the respective housing is protected from moisture, dust, and other possible contaminants by means of a respective cover, which preferably provides, among other things, a seal made of a plastic material. Furthermore, a removable cover offers the advantage that, in the event of a malfunction or defect, the drive and the guide part can be replaced or repaired. Thus, the drive and the guide part are reusable. A further advantage of a cover is that it reduces noise, enabling quiet operation of the braking device.

[0047] Preferably, the first housing has a first through-hole, and the second housing has a second through-hole. Advantageously, the through-holes in the respective housings are designed, for example, for cable feedthroughs, as well as for a shaft feedthrough or actuator feedthrough. The through-holes are designed so that the shaft or actuator can move smoothly. Furthermore, the option is provided for mounting a cable strain relief and a cable kink protection device on an outer side of the through-holes with respect to at least one cable feedthrough to prevent potential cable breakage.

[0048] The shaft is expediently arranged in a direction toward the second housing. The protruding arrangement of the drive advantageously creates optimal use of installation space.

[0049] The guide part is expediently movable back and forth within the second housing. This advantageously enables a pivoting movement of the first brake element and the second brake element by displacing the guide part within the second housing in a controlled manner. Depending on the position of the guide part, the loading device is in the release position or the holding position.

[0050] According to a preferred embodiment, a first material section with a first eye extends from the first brake member in a direction toward the second brake member. According to a further preferred embodiment, a second material section with a second eye extends from the second brake member in a direction toward the first brake member. Preferably, the first eye and the second eye are each formed as an elongated hole. Furthermore, a pin expediently extends through the first eye of the first material section and / or the second eye of the second material section.

[0051] Overall, it is favorable that the first material section and the second material section are arranged overlapping, wherein preferably the first material section is arranged below the second material section.

[0052] Advantageously, a scissor-like arrangement of the two material sections makes optimal use of the installation space to provide a compact braking device.

[0053] The pin expediently acts as an end stop for the first brake element and the second brake element. Advantageously, a flat section of material with a respective elongated hole extends from each of the two brake elements. By having a pin penetrating the two openings designed as elongated holes, the pivotability of the brake elements is restricted by the pin acting as an end stop. The advantage is that in the event of a malfunction or defect, the two brake elements cannot be pivoted or displaced outside a designated range. The end stop designed as a pin blocks further undesired pivoting of the first and second brake elements both in the holding position and in the release position. In this way, the operational safety of the braking device is reliably ensured.

[0054] According to a preferred embodiment, the first brake member and the second brake member are each produced from at least one plastic material using an injection molding process. Advantageously, plastic parts can be produced quickly and economically in large quantities using an injection molding process. A further advantage is that, due to their density properties, plastic parts are generally lighter than identical components made of, for example, metallic materials. Furthermore, the brake members produced as plastic parts can comprise a plurality of plastic materials, for example using a double injection molding process. Advantageously, a brake member therefore has at least two different plastic materials. The brake member is thus produced from a primary plastic material, with, for example, a further rubber-like plastic material with a friction surface being arranged in the concave contact region of the brake member in order to absorb the frictional force orto increase the holding force or braking force between the permanent brake or the drivable part and the braking element.

[0055] Overall, it is advantageous that the first and second brake elements can be pivoted synchronously. This advantageously transfers a uniform braking force to the driven part. This results in maximum braking efficiency, quiet operation of the braking system, and an increased service life of the components.

[0056] Further advantages, properties, features and developments of the invention emerge from the following description of a preferred embodiment and from the dependent claims.

[0057] The invention is explained in more detail below with reference to the accompanying drawings. Fig. 1 shows a perspective schematic view of the braking device according to the invention from above. Fig. 2 shows a plan view of the braking device from Fig. 1 in the holding position. Fig. 3 shows a top view of the braking device from Fig. 1 in the release position.

[0058] Fig. 1 shows schematically a braking device 10 for a drivable part 11 in a perspective view from above. The braking device 10 comprises an electrically driven, switchable loading device 12 with a first braking element 13 and a second braking element 14 as well as a permanent brake 17 presettable with respect to a braking torque. The loading device 12 essentially has two functions, namely a first holding position according to Fig. 1 as well as Fig. 2 and a second release position according to Fig. 3 The drivable part 11, which is Fig. 1 not shown in full for reasons of clarity, comprises a section that is coupled to the permanent brake 17, for example by means of a positive shaft-hub connection. Accordingly, in the release position, the drivable part 11 is freely rotatable together with the permanent brake 17. Fig. 1 a housing section 17a of the permanent brake 17 is shown in the holding position. In the holding position, which is also shown in Fig. 2 As shown, the first brake member 13 and the second brake member 14 of the loading device 12 engage like a pair of pliers around a radial outer surface of the housing section 17a of the permanent brake 17. In order to achieve better adhesion and a higher braking effect on the part of the loading device 12, the first brake member 13 and the second brake member 14 have a concave braking contact surface 19, which in Fig. 3 is shown, the radius of which corresponds to an outer radius of the housing section 17a of the permanent brake 17. Furthermore, the two concave brake contact surfaces 19 can each have a plastic coating, e.g., made of a rubber-like material.

[0059] In the holding position, the housing section 17a of the permanent brake 17 is in a locked state. Consequently, any further rotation of the housing section 17a of the permanent brake 17 is prevented. The drivable part 11 is now subjected to a precisely preset braking torque, which is delivered exclusively by the permanent brake 17. However, it is necessary that the braking torque of the loading device 12 corresponds to a value approximately twice higher than the preset braking torque of the permanent brake 17. In this way, it is prevented that the locked housing section 17a of the permanent brake 17 in the holding position slips between the first braking element 13 and the second braking element 14. In order to return to the release position, which in Fig. 3 To achieve this, as shown, the first brake element 13 and the second brake element 14 are held at a radial distance 18 of approximately 0.5 mm from the housing section 17a of the permanent brake 17. Advantageously, the activation or deactivation of the loading device 12 takes only approximately 60 milliseconds, thus ensuring very high operational reliability due to the short reaction time.

[0060] The first brake member 13 comprises a first end 25 and an opposite second end 26, wherein the second end 26 of the first brake member 13 is designed as a first housing 22 for accommodating a drive 16, in particular a direct current motor or DC motor. The first end 25 of the first brake member 13 has a region in which a first recess for connecting a first pivot joint 20 is arranged.

[0061] The second brake member 14 comprises a first end 27 and an opposite second end 28, wherein the second end 28 of the second brake member 14 is designed as a second housing 23 for receiving at least one guide part 24, e.g., a screw nut 24. The first end 27 of the second brake member 14 has a region in which a second recess for connecting a second pivot joint 21 is arranged.

[0062] A direct current motor or a DC motor with a rotatable shaft 16a is inserted into the first housing 22 of the first brake member 13 in a direction toward the second housing 23 of the second brake member 14. The second housing 23 comprises at least one insertable guide part 24, which is movable back and forth within the second housing 23. The guide part 24 is a screw nut 24.

[0063] A coupling part 31 having an external thread is arranged on the shaft 16a of the DC motor. Because the first housing 22 and the second housing 23 have a first through-hole 29 and a second through-hole 30 on the end face, the coupling part 31 is coupled to the screw nut 24 by the coupling part 31 passing through the screw nut 24 and the second through-hole 30. For this purpose, the coupling part 31 and the screw nut 24 each have a corresponding internal thread and external thread, respectively, creating a screw connection.

[0064] In order for the loading device 12 to move into the holding position, the rotating shaft 16a drives the coupling part 31 within the screw nut 24, so that the first housing 22 and the second housing 23 approach each other until the housing section 17a of the permanent brake 17 is radially packed in a region of the brake contact surface 19 by means of the first brake member 13 and the second brake member 14.

[0065] To return to the release position according to Fig. 3 the loading device 12, the rotating shaft 16a drives the coupling part 31 in an opposite direction within the screw nut 24, so that the first housing 22 and the second housing 23 move away from each other until the housing section 17a of the permanent brake 17 is completely released by means of the first brake member 13 and the second brake member 14.

[0066] The second housing 23 acts as a kind of abutment for the inserted screw nut 24, wherein the second through opening 30 is designed in the manner of an elongated hole in order to ensure a back and forth movement of the guide part 24 together with the coupling part 31 within the second housing 23.

[0067] Instead of a motor with a rotatable shaft 16a, a linear motor or a linear actuator with a linearly moving coupling part 31 can be considered, which can be coupled to an opposite guide part 24. In the case of a linear movement of the coupling part 31, the guide part 24 comprises, for example, a joint-like connecting element.

[0068] An end stop of the braking device 10 is arranged adjacent to the first housing 22 of the first braking element 13 and adjacent to the second housing 23 of the second braking element 14. A first flat material section 32 with a first eye 34 formed as an elongated hole extends from the first braking element 13 in a direction toward the second braking element 14. A second flat material section 33 with a second eye 35 formed as an elongated hole extends from the second braking element 14 in a direction toward the first braking element 13. The first material section 32 and the second material section 33 are arranged overlapping, with a pin 36 passing through the first eye 34 and the second eye 35. The pin 36 acts as an end stop, which limits the pivoting movement of the first braking element 13 and the second braking element 14 both in a direction toward the holding position and in a direction toward the release position.

[0069] Furthermore, the first housing 22 of the first brake element 13 and the second housing 23 of the second brake element 14 each comprise a removable cover, which is, for example, clipped, plugged, or screwed on. For the sake of clarity, no cover is shown in the figures. The covers of the respective housings 22; 23 each further comprise a seal that protects the contents of the housings 22; 23 from moisture, dust, dirt, or other unwanted components. In addition, the first housing 22 comprises a cable strain relief and a cable kink protection to increase the service life of the electric drive's cables.

[0070] For reasons of economy, weight, and electrical insulation, the first brake element 13 and the second brake element 14 are manufactured from at least one plastic material using an injection molding process. Furthermore, the use of plastic materials for the above-mentioned braking device 10 offers a reduced noise level during operation.

Claims

1. Braking device for a driveable part (11), in particular for use for a vehicle door or a vehicle flap, in particular in an automobile, comprising a driveable loading device (12) which can be brought into radial contact with the driveable part (11), with a first holding position and a second releasing position, wherein in the holding position at least one braking member (13; 14) bears frictionally against a radial circumference (15) of the driveable part (11) and secures the driveable part (11) against rotation with a pre-settable force, wherein in the releasing position the braking member (13; 14) is spaced from the radial circumference (15) of the driveable part (11) and permits a freewheeling of the driveable part (11), wherein the loading device (12) is adjustable between the holding position and the releasing position by means of a drive (16), characterized in that the driveable part (11) is coupled to at least one permanent brake (17), that the braking member (13; 14) of the loading device (12) can be brought into radial contact with a housing portion (17a) of the permanent brake (17), that in the holding position a braking torque of the permanent brake (17) acts on the driveable part (11), and that in the releasing position the driveable part (11) is freely rotatable with the permanent brake (17).

2. Braking device according to claim 1, characterized in that the driveable part (11) comprises a shaft or a spindle.

3. Braking device according to claim 1 or 2, characterized in that the braking torque of the permanent brake (17) is between 0.2 Nm and 3 Nm, preferably between 0.5 Nm and 2 Nm, and particularly preferably 1 Nm.

4. Braking device according to any of claims 1 to 3, characterized in that a braking torque of the loading device (12) is at least twice as high as the braking torque of the permanent brake (17).

5. Braking device according to any of claims 1 to 4, characterized in that the loading device (12) is switchable.

6. Braking device according to any of claims 1 to 5, characterized in that the driveable part (11) is arranged concentrically and / or coaxially with respect to the permanent brake (17).

7. Braking device according to any of claims 1 to 6, characterized in that the permanent brake (17) is configured as a permanent magnet brake and / or as a permanent spring-loaded brake.

8. Braking device according to any of claims 1 to 7, characterized in that an overrunning of the driveable part (11) in the manner of a slipping clutch is provided when the braking torque of the permanent brake (17) is exceeded in the holding position.

9. Braking device according to any of claims 1 to 8, characterized in that in the holding position the housing portion (17a) of the permanent brake (17) which is retained by the braking member (13; 14) is held in position in a non-rotatable manner upon overrunning of the driveable part (11).

10. Braking device according to any of claims 1 to 9, characterized in that in the releasing position a radial distance (18) between the housing portion (17a) of the permanent brake (17) and the braking member (13; 14) is between 0.2 and 1.2 millimeters, preferably between 0.4 and 0.8 millimeters and particularly preferably 0.5 millimeters.

11. Braking device according to any of claims 1 to 10, characterized in that a braking contact surface (19) of the braking member (13; 14) is concave.

12. Braking device according to any of claims 1 to 11, characterized in that the permanent brake (17) has a cylindrical or conical or ellipsoidal or hourglass-shaped external geometry.

13. Braking device according to any of claims 1 to 12, characterized in that the drive (16) is a direct current motor, and that the drive (16) comprises a shaft (16a) which is rotatable in two directions.

14. Braking device according to any of claims 1 to 12, characterized in that the drive (16) is a linear motor or a linear actuator or an electromagnetic actuator.

15. Braking device according to any of claims 1 to 14, characterized in that the driveable loading device (12) comprises a first braking member (13) and a second braking member (14) each of which in the holding position bear frictionally against a radial circumference (15) of the driveable part (11) and secure the driveable part (11) against rotation with a pre-settable force and in the releasing position are spaced from the radial circumference (15) of the driveable part (11) and permit a freewheeling of the driveable part (11), wherein the first braking member (13) is pivotable in an articulated manner about a first pivot joint (20) with a first pivot axis (20a), wherein the second braking member (14) is pivotable in an articulated manner about a second pivot joint (21) with a second pivot axis (21a), and wherein the driveable part (11) is arranged between the drive (16) of the loading device (12) and the two pivot axes (20a; 21a).