Patent Application
20190152460
The subject disclosure relates to the art of braking systems and, more particularly, to an electromechanical brake including a parking lock.
Electromechanical brake systems rely on an electric signal to operate a brake actuator or caliper. The electric signal activates a motor which drives a gear system coupled to the caliper. The motor shifts the caliper so as to bring together brake pads with a rotor. The motor does not include a locking feature. Accordingly, a separate mechanical system is employed to provide a parking brake. Typically, the separate mechanical system includes a cable or hydraulic conduit that delivers a clamping force to the caliper. The use of cables and/or hydraulics increases an overall cost and complexity of the braking system. Accordingly, it is desirable to provide a braking system in which a parking brake may be integrated into an electromechanical brake system.
In accordance with an aspect of an exemplary embodiment an electromechanical brake system includes a caliper including a first caliper member and a second caliper member, an electric motor mounted to the caliper, a gear element mechanically connected to the electric motor, an actuator supported by the caliper, the actuator including an actuation member, and a controller operatively connected to the actuator. The controller is operable to selectively engage the actuation member with the gear element to positionally lock the first caliper member relative to the second caliper member.
In addition to one or more of the features described herein include wherein the actuator comprises a solenoid and the actuation member comprises a solenoid plunger.
In addition to one or more of the features described herein include wherein the gear element includes a parking gear including a plurality of tooth elements, each of the plurality of tooth elements including at least one surface that extends at a non-zero angle relative to a radius of the gear element.
In addition to one or more of the features described herein include wherein the actuation member includes a terminal end portion including an angled surface.
In addition to one or more of the features described herein include a biasing element operatively connected to the actuation member, the biasing element biasing the actuation member in one of a deployed configuration and a non-deployed configuration.
In addition to one or more of the features described herein include wherein the biasing element biases the actuation member in each of the deployed configuration and the non-deployed configuration.
In addition to one or more of the features described herein include wherein the biasing element comprises an over-center spring.
In accordance with another aspect of an exemplary embodiment, a vehicle includes a body, a prime mover connected to the body, a plurality of wheels connected to the prime mover, and an electromechanical brake system operatively connected to at least one of the plurality of wheels. The electromechanical brake system includes a caliper including a first caliper member and a second caliper member, an electric motor mounted to the caliper, a gear element mechanically connected to the electric motor, an actuator supported by the caliper, the actuator including an actuation member, and a controller operatively connected to the actuator. The controller is operable to selectively engage the actuation member with the gear element to positionally lock the first caliper member relative to the second caliper member.
In addition to one or more of the features described herein include the actuator comprises a solenoid and the actuation member comprises a solenoid plunger.
In addition to one or more of the features described herein include wherein the gear element includes a parking gear including a plurality of tooth elements, each of the plurality of tooth elements including at least one surface that extends at non-zero angle relative to a radius of the gear element.
In addition to one or more of the features described herein include wherein the actuation member includes a terminal end portion including an angled surface.
In addition to one or more of the features described herein include a biasing element operatively connected to the actuation member, the biasing element biasing the actuation member in one of a deployed configuration and a non-deployed configuration.
In addition to one or more of the features described herein include wherein the biasing element biases the actuation member in each of the deployed configuration and the non-deployed configuration.
In addition to one or more of the features described herein include wherein the biasing element comprises an over-center spring.
In accordance with another aspect of an exemplary embodiment, a method of applying a parking brake for an electromechanical brake system includes activating an electric motor, rotating a gear element with the electric motor, applying a clamping force to a brake disc through rotation of the gear element, energizing an actuator to deploy an actuation element, and locking rotation of the gear element with the actuation element.
In addition to one or more of the features described herein include de-activating the electric motor.
In addition to one or more of the features described herein include re-activating the electric motor to further rotate the gear element without releasing the actuation element.
In addition to one or more of the features described herein include re-activating the electric motor, releasing the actuation element, and de-activating the electric motor.
The above features and advantages, and other features and advantages of the disclosure are readily apparent from the following detailed description when taken in connection with the accompanying drawings.
Other features, advantages, and details appear, by way of example only, in the following detailed description, the detailed description referring to the drawings in which:
The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. As used herein, the term module refers to processing circuitry that may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
A vehicle, in accordance with an aspect of an exemplary embodiment, is indicated generally at 10 in
Referring to
In accordance with an exemplary aspect, electromechanical brake system 40 includes a parking lock 54 mounted to caliper 44. Parking lock 54 includes an actuator 56 having an activation member 58 (
Referring to
Referring to
Solenoid 90 includes a biasing element, shown schematically in
Reference will now follow to
In block 148 parking lock control system 60 may signal activation module 64 to re-activate electromechanical brake system 40 and apply an additional clamping force through caliper 44. The re-activation of electromechanical brake system 40 may occur after a period of time of about 3-5 minutes from deactivation. The additional clamping force may cause rotation of gear element 51 such that activation member 58 ratchets over parking gear 96. In this manner, electromechanical brake system 40 may be adjusted to accommodate any dimensional changes of braking components that may occur as a result of cooling without releasing parking lock control system 60.
In block 160, a determination is made whether a parking lock release signal has been received. If the release signal is received, electric motor 48 is energized in block 162 causing caliper 44 to apply the clamping force and relieve pressure from parking gear 96. In block 164, activation member 58 is shifted to the de-activated configuration and in block 166 electric motor 48 is de-energized, releasing caliper 44 such that vehicle 10 may move.
While the above disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope thereof.
