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.

Electric parking brake apparatus

An electro-hydraulic braking system of the type which operates normally in a brake-by-wire mode wherein hydraulic pressure is applied to braking devices at the vehicle wheels in proportion to the driver's braking demand as sensed electronically at a brake pedal (10), and which, if the brake-by-wire mode should fail, operates in a push-through mode wherein hydraulic pressure is applied to the braking devices at the vehicle wheels by way of a master cylinder (34) coupled mechanically to the brake pedal (10), the system including also an electric parking braking means for enabling the braking devices to be actuated for parking braking purposes but which is also arranged to be activated to supplement push-through braking in the event of failure of the break-by-wire mode. Electro-hydraulic braking at the rear axle of the vehicle is allowed only when a control unit (13) of the electro-hydraulic braking system has confirmation that the electric parking means is in a satisfactory operational state.

Back-up braking in electro-hydraulic (EHB) braking system

The invention relates to a brake system (10) for a vehicle having a parking brake with an air-quantity-boosting valve device (34) for aerating and deaerating at least one spring brake cylinder (14) of the parking brake, having at least one electrically actuable control valve (52) for controlling the air-quantity-boosting valve device (34), having an electrical control device (12), which is electrically coupled to the electrically actuable control valve (52), for controlling the electrically actuable control valve (52), and having an electrical actuating device (122), which is coupled to the control device (12), for actuating the parking brake. In order to be able to resort to available series-produced components, the air-quantity-boosting valve device (34), the control valve (52), the electrical control device (12) and the actuating device (122) are in each case embodied as autonomous, separate components which are arranged spatially separate from one another.

Brake system for a vehicle

The present invention relates to an electro-hydraulic brake system for motor vehicles which is controllable in a ‘brake-by-wire’ operating mode by the vehicle operator as well as independently of the vehicle operator, and which can be operated in a back-up operational mode where only operation by the vehicle operator is possible. The brake system includes an emergency pressure generator or master brake cylinder which has at least one pressure chamber and is operable by means of a brake pedal, and a hydraulic auxiliary pressure source whose pressure is used to act upon wheel brakes that are connectable to the master brake cylinder by way of at least one hydraulic connection closable by means of a separating valve, as well as an electronic control and regulating unit. In order to achieve a very rapid change-over of the separating valves into the closing position, the present invention arranges for an additional electric circuit that actuates the separating valve independently of the electronic control and regulating unit as the driver's deceleration demand occurs.

Electrohydraulic brake system for motor vehicles

Combined vehicle braking system, in particular for motor vehicles, comprising an electromechanical service brake system for a first axle of the vehicle, said electromechanical brake system comprising at least one electromechanically actuatable wheel brake (2), and comprising a hydraulic service brake system for a second axle of the vehicle, said hydraulic brake system comprising a main brake cylinder (4) and at least one hydraulically actuatable wheel brake (1), wherein the first axle is a front axle (FA) and the second axle is a rear axle (RA).

Combined vehicle brake system with hydraulically and electromechanically actuatable wheel brakes

A vehicle braking system comprising an electro-hydraulic braking system of the type which operates normally in a brake-by-wire mode wherein hydraulic pressure is applied to braking devices at the vehicle wheels (18 a-d) in proportion to the driver's braking demand as sensed electronically at a brake pedal (10), and which, if the brake-by-wire mode should fail, operates in a push-through mode wherein hydraulic pressure is applied to the braking devices at the vehicle wheels (18) by way of a master cylinder (34) coupled mechanically to the braked pedal (10), and an electric parking braking system for enabling the braking devices to be actuated for parking braking purposes. For supplementing the push-through braking provided by the electro-hydraulic braking system in the event that the brake-by-wire mode has failed, it is arranged that the operation of the brake pedal (10) by the driver also causes operation of the electric parking braking system.

Back-up braking in vehicle braking systems

A vehicle braking system comprising an electro-hydraulic braking means of the type which operates normally in a brake-by-wire mode wherein hydraulic pressure is applied to braking devices at the vehicle wheels (18a-d) in proportion to the driver's braking demand as sensed electronically at a brake pedal (10), and which, if the brake-by-wire mode should fail, operates in a push-through mode wherein hydraulic pressure is applied to the braking devices at the vehicle wheels (18) by way of a master cylinder (34) coupled mechanically to the brake pedal (10), and an electric parking braking means for enabling the braking devices to be actuated for parking braking purposes. For supplementing the push-through braking provided by the electro-hydraulic braking means in the event that the brake-by-wire mode has failed, it is arranged that the operation of the foot pedal (10) by the driver also causes operation of the electric parking braking.

Alan Leslie Harris

Papers

Back-up braking in vehicle braking systems

Improved back-up braking in vehicle braking systems

Bremsunterstützung in kraftfahrzeugbremssystemen