An Actuator for a Wheel Brake Unit of a Vehicle

Abstract

An actuator for a wheel brake unit of a vehicle is disclosed, wherein the actuator has an actuation element for performing an actuation, and is configured to receive, through a power supply, a power for performing the actuation. The actuator is characterized by a detection unit, configured to receive a control signal and to detect a power shortage indicative of an emergency situation, and to generate an emergency signal if the control signal is received or if the power shortage is detected, as well as by a backup energy storage, configured to store energy sufficient for causing the actuation element to perform a complete brake actuation at least once and, upon receiving the emergency signal, to provide at least a part of the energy needed by the actuation element to perform the actuation.

Claims

1-11. (canceled)

12. An actuator for a wheel brake unit of a vehicle, comprising: an actuation element that performs an actuation and is configured to receive, through an energy store, energy for performing the actuation, and a backup energy storage configured to store energy sufficient for causing the actuation element to perform a complete brake actuation at least once, and to provide the energy needed by the actuation element in an emergency situation.

13. The actuator according to claim 12, wherein the backup energy storage is configured to receive a signal, and to provide, upon receiving the signal, at least a part of the energy needed by the actuation element to perform the actuation.

14. The actuator according to claim 13, further comprising: a detection unit configured to detect a power shortage indicative of an emergency situation, and to generate an emergency signal to trigger a generation of the signal.

15. The actuator according to claim 12, further comprising: a housing accommodating the backup energy storage.

16. The actuator according to claim 12, wherein the backup energy storage is configured to store electric energy.

17. The actuator according to claim 16, wherein the backup energy storage is configured to store the electric energy within one or more of the following devices: a capacitor, a supercapacitor, an ultracapacitor, or a rechargeable battery.

18. The actuator according to claim 12, wherein the backup energy storage stores mechanical energy.

19. The actuator according to claim 12, further comprising: an electronic control unit, wherein the backup energy storage is integrated into the electronic control unit.

20. A wheel brake unit, comprising: a wheel brake; and an actuator according to claim 12.

21. A method for performing a safety actuation for a wheel brake unit of a vehicle, wherein an actuator comprises an actuation element that performs an actuation and is configured to receive, through an energy store, energy for performing the actuation, the method comprising: storing, in a backup energy store, energy sufficient for causing the actuation element to perform a complete brake actuation at least once; and providing, from the backup energy store, energy needed by the actuation element in an emergency situation.

22. The method according to 21, further comprising: receiving a signal, by the backup energy storage; and providing, upon receiving the signal, at least a part of the energy needed by the actuation element to perform the actuation.

23. The method according to claim 22, further comprising: detecting a power shortage indicative of an emergency situation; and generating an emergency signal in order to trigger a generation of the signal to be received by the backup energy storage.

24. A computer product comprising a non-transitory computer-readable medium having stored thereon program code which, when the program code is executed on a computer or data processing unit; causes the acts of: storing, in a backup energy store, energy sufficient for causing the actuation element to perform a complete brake actuation at least once; and providing, from the backup energy store, energy needed by the actuation element in an emergency situation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 depicts an actuator in a wheel brake unit of a vehicle with a backup energy storage to perform an emergency brake actuation.

[0027] FIG. 2 depicts some further details for a wheel brake unit with an electro-mechanical actuator.

[0028] FIG. 3 displays steps of a method for performing a safety actuation for a wheel brake unit of a vehicle.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 schematically depicts an actuator 100 in a wheel brake unit 200 of a vehicle. The actuator 100 comprises an actuation element 110 for performing an actuation of the brake, by means of a transmission and brake mechanism 210. The actuation element 110 may be an electric motor. In normal use, power for the actuation element 110 is received through a power supply 50. The actuator further comprises a backup energy storage 130. The backup energy storage is configured to receive a signal over the signal input line 70, which may be issued by a driver and/or by another component of the vehicle. The signal may in particular request an emergency actuation from the actuation element 110 causing a brake application or a brake release. In case of an emergency situation, and/or in the case where the backup energy storage 130 receives the signal, the actuation may trigger the service brake or the parking brake.

[0030] In addition, a detection unit may be configured to detect further signs indicative of an emergency, such as a power drop or fluctuation within a specified time, or a driving status of the vehicle via wheel speed sensors and/or via a component of an automated driving system. Furthermore, the detection unit may be configured to receive a control signal over the control signal input line 70, which may be issued by a driver and/or by another component of the vehicle. The control signal may in particular admit an interpretation by the detection unit, requesting an actuation from the actuation element 110 causing a brake application or a brake release. Both in the case where the detection unit detects a power shortage indicative of an emergency situation, and in the case where the detection unit receives a control signal, the actuation may trigger the service brake or the parking brake.

[0031] The backup energy storage 130 is configured to store sufficient energy for causing the actuation element 110 to perform a complete braking of the vehicle at least once. The energy should therefore suffice to cause the service brake to fully stop the vehicle. Advantageously, it also suffices for application of the parking brake. The backup energy storage 130 is configured to provide the energy needed by the actuation element 110 to perform the actuation in an emergency situation.

[0032] FIG. 2 schematically displays some additional details for an embodiment of an electro-mechanical actuator 100 in a vehicle wheel brake unit. Depicted in the electro-mechanical actuator 100 is an actuation element 110 which is an electric motor, a function for actuation of a parking brake 150, and an electronic control unit 140 for the electric motor 110. The electronic control unit 140 is connected to a local backup energy storage 130, which is placed internally in the actuator 100 and supports at least one brake actuation or deactuation.

[0033] FIG. 2 provides further details for one particular realization of the transmission and brake mechanism 210 for braking the wheel 30. The transmission and brake mechanism 210 comprises a caliper unit with an internal transmission system, as e.g. a lever 220. A clamping force on the wheel is realized by the electric motor 110 by means of a connection provided by an appropriate actuating element 212 and the lever 220, which is in direct connection with a brake pad push member 230 to operate the brake pad 240.

[0034] Under normal operation conditions, the wheel brake actuator 100 utilizes energy from an external energy supply 50 (not depicted in FIG. 2). In case of emergency, the internal backup energy storage 130 can provide sufficient energy to apply the brakes, to perform an emergency braking or an emergency release of the brake.

[0035] The present transmission and brake mechanism 210 is to be understood as a particular example. In other embodiments it may be replaced by any other system achieving the effect of braking the wheel via a force derived from the electro-mechanical actuator 100. Thus the electro-mechanical actuator 110 may be part of a different brake unit, as e.g. a drum brake, rather than the brake unit in the depicted embodiment.

[0036] A further purpose of the figures is to illustrate how components of the electro-mechanical actuator may be integrated into other components, or realized as executable software code. In the present embodiment, the detection unit may be integrated as a function into the electronic control unit 140, which is in addition configured to provide other services for operating the electric motor 110. Also, the backup energy storage 130 is included in the electronic control unit 140.

[0037] FIG. 3 shows steps of a method for performing a safety actuation for a wheel brake unit 200 of a vehicle, wherein the wheel brake unit 200 comprises an actuator 100 with an actuation element 110 for performing an actuation, and the actuator 100 is configured to receive, through a power supply 50, a power for performing the actuation. One step comprises storing S110 sufficient energy for causing the actuation element 110 to perform a complete brake actuation at least once. This storing of energy occurs locally within a dedicated backup energy storage 130 of the actuator.

[0038] A further step is providing S140, in an emergency situation, at least a part of the energy needed by the actuation element 110 to perform the actuation, utilizing the energy stored in the backup energy storage 130.

[0039] The method may also be a computer-implemented method. A person of skill in the art would readily recognize that steps of the above-described method may be performed by programmed computers. Embodiments are also intended to cover program storage devices, e.g., digital data storage media, which are machine or computer readable and encode machine-executable or computer-executable programs of instructions, wherein the instructions perform some or all of the acts of the above-described methods, when executed on the computer or processor.

[0040] The description and drawings merely illustrate the principles of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope.

[0041] Furthermore, while each embodiment may stand on its own as a separate example, it is to be noted that in other embodiments the defined features can be combined differently, i.e. a particular feature described in one embodiment may also be realized in other embodiments. Such combinations are covered by the disclosure herein, unless it is stated that a specific combination is not intended.

TABLE-US-00001 LIST OF REFERENCE SIGNS 50 power supply 70 signal input line 100 actuator 110 actuation element 130 backup energy storage 140 electronic control unit 150 function for actuation of parking brake 200 wheel brake unit 210 transmission and brake mechanism 212 actuating element 220 lever 230 brake pad push member 240 brake pad 250 brake disk