292 results about "Electric parking brake" patented technology

A friction member driven by a motor is pressed against a rotating element that rotates integrally with a wheel to give a pressing force to the rotating element, thereby applying braking force to the wheel. Control means controls the control circuit that controls the motor. In order to apply braking force to the wheel, the control means commands the control circuit to drive the motor once or a plurality of times at a predetermined time interval. Determining means determines a temperature of the friction member at the time when the parking brake starts braking the wheel. Setting means sets at least one of the number of driving of the motor, the time interval, and the target value of the pressing force. Therefore, a steady braking force with high efficiency is generated.

A vehicle stop determination apparatus includes a vehicle speed sensor for detecting a speed of a vehicle, a G sensor for detecting a longitudinal acceleration of a vehicle, an inclination acceleration estimate section for calculating an estimated inclination acceleration resulting from an inclination of a road surface based on a vehicle speed reduction rate calculated from an output of the vehicle speed sensor and an output from the G sensor, and a stop determination section which has a first stop determination mode and a second stop determination mode and which selects the first stop determination mode or the second stop determination mode based on the vehicle speed reduction rate provided before the output of the vehicle speed sensor becomes equal to or less than a detection limit. Also, the inclination is re-determined based on the output of the G sensor when the vehicle is stopped.

An electric parking brake control apparatus includes: an electric parking brake actuator that pulls cables connected to respective parking brake units of wheels; a brake actuator that controls braking pressures applied to the wheels by service brakes; a pressure-increase control unit that controls the brake actuator to increase the braking pressures to a predetermined value, when a tension of the cables falls below a predetermined target tension after the cables are pulled until the target tension is achieved; and a tension-increase control unit that controls the electric parking brake actuator to pull the cables until the tension of the cables exceeds the target tension, after the brake pressures are increased by the pressure-increase control unit.

The invention relates to a brake device for a vehicle comprising a hydraulic service brake system with a power supply unit, which builds up a brake pressure inside a brake master cylinder of the service brake system according to a pressure demand, this brake pressure being transferred to at least one wheel brake, and comprising an electric parking brake system. The inventive brake device is characterized in that during the operation of the service brake system, a control unit verifies whether a defect exists in the service brake system on the basis of a comparison of the pressure demand with the brake pressure in at least one wheel brake and/or on the basis of a comparison between a recorded vehicle acceleration and an acceleration of the vehicle expected due to the pressure demand, and that the control unit activates the electric parking brake system when the existence of a defect is established. The invention also relates to a method for controlling the brake system of a vehicle.

An electric parking brake control apparatus for controlling an electric actuator for driving a parking brake is provided with: an inclination determination unit for determining an inclination of a road surface based on at least a change of a vehicle speed; and a braking force setting unit. The braking force setting unit sets a braking force of the parking brake to a slope braking force which is larger than a flat ground braking force set when the vehicle is stopped on a flat ground, according to an inclination of the road surface which is determined by the inclination determination unit. Moreover, in the event that the vehicle is stopped again without experiencing a running over a predetermined vehicle speed after braking with the slope braking force has been cancelled, the braking force setting unit sets the braking force to the slop braking force.

An electric parking brake system is equipped with a parking brake driven by an electric actuator for braking wheels of a vehicle, a vehicle condition sensing section for detecting vehicle conditions, a target braking force setting section for setting a target braking force on the basis of vehicle condition detected, compared and weighted by the vehicle condition sensing section so as to overcome a trouble of a part of sensing section, a parking condition detecting section for sensing a change of the vehicle condition from a stopping condition to a parking condition, and a control section for increasing a braking force according to the change in the vehicle condition so as to avoid a creep movement of the vehicle. Thereby, the electric parking brake system with a highly improved reliability can be provided.

When a driver operates an activation switch, an electric parking brake apparatus performs a parking brake activation control in order to operate an electric motor until the tension of a base wire reaches a predetermined target tension to thereby bring parking brakes into an activated state. After that, the apparatus again performs the parking brake activation control when a re-activation time, which is set in accordance with the difference between an estimated temperature of a service brake and an ambient temperature, has elapsed; when the position of a shift lever has been changed; when the height of the vehicle has changed by an amount greater than a predetermined amount; or when the driver releases a brake pedal which has been continuously operated after completion of the parking brake activation control.

When supplied with a signal for correcting a vehicle behavior is input from a brake controller, an electrically-driven parking brake controller releases actuation of an electrically-driven parking brake when the electrically-driven parking brake is actuated. When supplied with a brake control amount when abnormality occurs in a main brake system is input the electrically-driven parking brake controller drives electric motors to generate the brake control amount concerned. Furthermore, when supplied with the brake control amount of the electrically-driven parking brake 30 from an ACC system, the electrically-driven parking brake controller drives the electric motors to generate the brake control amount concerned. The front-and-rear driving force distribution controller directly couples the front shaft and the rear shaft when the electrically-driven parking brake is actuated.

An electric parking brake control unit of an electric parking brake apparatus has an input section for receiving signals for performing automatic activation and deactivation, but does not have a determination function and a circuit for inputting signals from various sensors, which are necessary to determine whether to start the automatic activation/deactivation control. Therefore, when used in a vehicle which does not require an automatic control function and requires only a manual control function, the electric parking brake control unit can be used solely, with no signal line connected to the input section. When used in a vehicle which requires both the automatic control function and the manual control function, the input section is connected to a second control unit that can output signals for performing automatic activation and deactivation, whereby the electric parking brake control unit operates in cooperation with the second control unit.

An electric parking brake assembly includes an electric motor having an output shaft, a control module coupled to the electric motor for controlling the electric motor and a transmission coupling a threaded lead screw to the output shaft of the electric motor. The transmission preferably includes a gear train having a plurality of helical gears and the lead screw and the output shaft are preferably coaxial. A stationary elongate guide shaft extends substantially parallel to and spaced apart from the lead screw. A drive nut has a lead screw bore threadably receiving the lead screw therein and a guide shaft bore slidingly receiving the elongate guide shaft therein. The drive nut also has a cable attachment for attaching a brake cable to the drive nut. The cable attachment has a central axis offset from a central axis of the lead screw and is preferably located midway between the lead screw bore and the guide shaft bore. The control module controls the electric motor such that rotation of the output shaft causes motion of the transmission and rotation of the lead screw, rotation of the lead screw causes linear motion of the drive nut along the lead screw and the guide shaft, and linear motion of the drive nut causes tensioning and untensioning of the brake cable. The assembly preferably includes a manual override device operatively connected to the lead screw. The manual override device selectively causes manual rotation of the lead screw, rotation of the lead screw causes linear motion of the drive nut, and linear motion of the drive nut causes tensioning and untensioning of the brake cable.

An electric parking brake for a vehicle, comprising a winch having a rotation axis, an electrical motor for turning the winch, and two braking cables fixed to the circumference of the winch on opposite sides, so that under a rotation of the winch segments of essentially equal length of the braking cables are wrapped onto the winch. The winch is disposed in a housing having oppositely disposed exit openings through which the cables pass, respectively, and tapered side walls for guiding the cables from the circumference of the winch to the exit openings.

An electric parking brake system includes motors, parking brakes, current a detection portion, a drive circuit, and a controller. The parking brakes are driven by the motors to apply braking force to wheels. The current detection portion detects the amount of current supplied to the motors. The drive circuit supplies a constant predetermined voltage to the motors. The controller controls supply of electricity to the motors. The drive circuit is controlled by the controller. When a detected current value exceeds a predetermined value, the controller stop supplying electricity to the motors.

A vehicle brake control system includes an improved ACC system for controlling the operation of a brake actuator and a throttle actuator, based on a signal from a preceding vehicle detector such as a radar device, so that a subject vehicle tracks a preceding vehicle. After a regular brake device is actuated to stop the subject vehicle, an EPB ECU disengages the regular braking device and, instead, actuates an electrically initiated and mechanically maintained parking brake device, so as to temporarily maintain the subject vehicle in a stationary state. Once the electric parking brake device is initiated, its braking state is mechanically maintained even if the flow of current is cut off. Therefore, neither the regular brake device nor the electric parking device consume power while the vehicle is in a stationary state, thereby saving power and minimizing electrical heat generation.

An electric parking brake actuator has a transmission mechanism, which is rotationally drivable by an electric motor and converts rotational movement into an axial movement of an actuating rod that carries an actuating element for the parking brake. The actuating rod normally moves by electric motor displacement via the transmission mechanism from an unblocking position to a blocking position and vice versa. A blocking mechanism serves the purpose of holding the actuating rod in the unblocking position of the actuating rod against the force of a spring element. A blocking disc, which is in drive connection with the transmission mechanism, has a stop surface for a locking device in only one rotational direction of the blocking disc. For secondary alternate operation the stop surface is releasable by the locking device so that the actuating rod is biased by the spring element to the blocking position without electric-motorized assistance.

A drum-integrated electric parking brake apparatus may include a drum brake in which a lining may be pivotally installed, and extends and presses a drum when a parking cable engaged with the lining may be pulled, an actuator selectively pulling the parking cable, a sensor member for detecting a rotation number of the actuator, and a controller for controlling the amount of current supplied to the actuator by detecting a change in the rotation number of the actuator.

In a vehicle parking system, when a selected shift position is changed between Park and a shift position other than Park, if both an electric motor of an electric parking lock mechanism and an electric motor of an electric parking brake mechanism are operated, these electric motors are started in such a manner that the times at which striking currents supplied to these electric motors reach their peaks are staggered.

Disclosed is a connecting device of a parking cable for an electric parking brake, which connects an actuator for the electric parking brake with a parking cable. The connecting device includes a connector and a reaction force member. The connector includes a small diameter section having one side into which an outer peripheral surface of the parking brake is inserted, a large diameter section that extends from the small diameter section to have a diameter larger than that of the small diameter section, an axial cutout slit axially formed through upper and lower surfaces of an outer peripheral portion of the large diameter section such that protrusions circumferentially protruding from the actuator are inserted into the axial cutout slit through the large diameter section, a circumferential cutout slit that extends from an inner end of the axial cutout slit in a circumferential direction, and a cutout groove that axially extends from the circumferential cutout slit. The reaction force member is inserted into the large diameter section to press the protrusions such that the protrusions are seated in the cutout groove through the axial cutout slit and the circumferential cutout slit. According to the connecting device, the assembly work is facilitated, so the assembly efficiency can be improved and connection work using the connector can be easily performed.

An actuator for an electric parking brake system has an outer housing. A planetary gear train and an electric motor are disposed in the outer housing. At least one gear connects the motor to the planetary gear train. The planetary gear train comprises a multi-stage planetary gear mechanism. A gear housing accommodates the planetary gear mechanism. The planetary gear train further comprises a centering pin extending through the gear mechanism, such that the planetary gear mechanism rotates about the centering pin. Each stage has a sun gear, a ring gear, a plurality of planet gears meshed with the sun gear and ring gear, and a planet carrier rotatably supporting the planet gears.

A sensor included in each brake system section detects the operation state of an electric parking brake in another brake system section. Based on the detected operation state, the sensor assumes the drive command that is to be output from a controller of the other brake system section to a controller of its own brake system section. The controller of one brake system receives an input of a drive command that is output from the controller of the other brake system. The controller of one brake system compares the assumed drive command (internal value) with the input drive command (input value). When the internal value and the input value do not match, the controller determines that an abnormality has occurred in the other brake system section.

An actuator for an electric parking brake system includes an outer housing, a motor, a planetary gear mechanism and a belt-wheel mechanism that are received in the outer housing, and an isolation member. The belt-wheel mechanism includes a driving wheel, a follower wheel, and a transmission belt. The driving wheel is connected with the motor. The follower wheel is connected with the planetary gear mechanism. The isolation member has a first spacer fixed to the driving wheel via the motor, a second spacer fixed to the follower wheel, and a buffering element disposed between the second spacer and the outer housing. The second spacer is disposed above and assembled to the first spacer. The isolation member defines the center-to-center distance between the driving wheel and the follower wheel, and absorbs vibrations from the motor and the planetary gear mechanism.

In a method and system for controlling a braking system, equipped with an electric parking brake, for a motor vehicle, the electric parking brake is released in response to an identification of a moving-off operation. A release instant of the electric parking brake is defined in dependence on at least one measured parameter of a clutch engagement operation. In comparison with a method and system in which, for example, the electric parking brake is released in dependence on the actuation of the accelerator by a driver, the method and system permit a more precise coordination of the deactivation of the electric parking brake with the clutch engagement operation, and thus with the moving-off operation of the vehicle, particularly in the case of a vehicle equipped with a manual transmission.