A vehicle brake system and method for increasing the brake pressure in a first wheel brake cylinder and for limiting the brake pressure in a second wheel brake cylinder of a vehicle brake system. The method includes increasing a first brake pressure in the first wheel brake cylinder by controlling/holding a wheel inlet valve in its open state and controlling/holding a first wheel outlet valve in its closed state, and limiting an increase of a second brake pressure in the second wheel brake cylinder during the transfer of brake fluid into the first wheel brake cylinder by controlling/holding a second wheel inlet valve in its closed state and controlling a second wheel outlet valve into its open state. The second wheel outlet valve is controlled with a pulse width-modulated signal so that during the transfer of brake fluid, the second wheel outlet valve is permanently in its open state.

Provided is a braking device for a vehicle comprising: a first hydraulic pressure generation unit which generates hydraulic pressure corresponding to the volume of a master chambers in the master chambers that change in volume according to the movement of master pistons; a second hydraulic pressure generation unit which is configured so as to be capable of generating a desired hydraulic pressure in a bottoming state in which the forward movement of the master pistons is restricted by a master cylinder; braking force generation units which apply the braking force corresponding to the input hydraulic pressure to wheels of a vehicle; and a braking force control unit which causes the second hydraulic pressure generation unit to generate hydraulic pressure in the bottoming state, and inputs the hydraulic pressure to the braking force generation units.

A method for boosting a braking force in an electronically slip-controllable vehicle brake system, as well as an electronically slip-controllable vehicle brake system. Vehicle brake systems of this kind are at least equipped with a power brake unit and electronic slip-controllable vehicle brake system. In the case of a malfunction of the power brake unit, the traction-slip control device (92) takes over the boosting. A method for determining a composite signal which is adjusted by controlling a drive of a pressure generator of the slip-controllable vehicle brake system accordingly. To this end, an electronic control unit records two mutually independent input quantities, converts these input quantities into evaluation signals and sums the evaluation signals mathematically to yield a composite signal. The latter represents a setpoint brake pressure that the slip-controllable vehicle brake system supplies by controlling a pressure generator accordingly.

A hydraulic pressure control unit and a vehicle brake system including the hydraulic pressure control unit are obtained. The hydraulic pressure control unit can downsize the brake system in comparison with a conventional brake system.

A hydraulic pressure control unit (50) is a hydraulic pressure control unit for a brake system (1) of a vehicle (100). The hydraulic pressure control unit (50) includes a pump (34) and an accumulator (33) in a secondary channel (14), the pump (34) increasing a hydraulic pressure of brake fluid; and the accumulator (33) storing the brake fluid. The secondary channel (14) is configured to allow a flow of the brake fluid that flows into the accumulator (33) from a suction side of the pump (34).

A method and a system for verifying normal operation of a negative pressure sensor of a brake booster is provided. The method and system verify whether the negative pressure sensor of the brake booster is in normal operation and the normal operation of the booster negative pressure sensor is detected by mutually verifying values measured by the booster negative pressure sensor and values measured by sensors that indirectly sense the booster negative pressure.

A vehicle braking system includes a wheel cylinder, a master cylinder, a brake pedal operable to transmit a user input force to the master cylinder, a primary braking unit including a first electronically controlled pressure generating unit distinct from the master cylinder and operable to generate a braking force at the wheel cylinder in a first mode of operation, a secondary braking unit including a second electronically controlled pressure generating unit distinct from the master cylinder and operable to generate a braking force at the wheel cylinder in a second mode of operation and a pedal feel simulator operable to provide feedback to the brake pedal according to a fixed characteristic of the pedal feel simulator defining a predetermined force-stroke relationship relating a travel distance of the brake pedal to the user input force. In the first mode of operation, the secondary braking unit is operable to receive fluid from the master cylinder to diverge from the predetermined force-stroke relationship at the brake pedal.

An electric automobile braking device includes a master cylinder that has no vacuum booster and a hydraulic booster device that can increase a brake fluid pressure generated by the master cylinder. Switching is possible between a normal braking mode in which hydraulic braking and regenerative braking are used in combination when a percentage charge of a battery is less than a threshold value and a regenerative braking restriction mode in which hydraulic braking is permitted and regenerative braking is restricted when the percentage charge is a threshold value or greater. In the regenerative braking restriction mode, when a depressing force of a brake pedal by a driver exceeds a first depressing force over a predetermined period of time, an operation of the hydraulic booster device is suppressed.

The method relates to a method for boosting the braking force in an electromotor operated slip-controllable vehicle brake system having electromechanical brake boosting. The vehicle brake system includes a braking-intention detection device, an electromechanically actuatable brake booster, and an electronically actuatable brake-pressure control device. In the event of a malfunction of the brake booster, the boosting of the brake pressure is alternatively assumed by the brake-pressure control device. In the event of a malfunction of the brake boosting, it is checked whether a generation and a transmission of a trigger signal representing the actuation of the braking-intention detection device from the first electronic control device of the brake booster to a second electronic control device of the brake-pressure control device is possible, and if this is so, the trigger signal is transmitted via an existing communications link between the control devices.

A vehicle braking system includes a wheel cylinder, a master cylinder, a brake pedal operable to transmit a user input force to the master cylinder, a primary braking unit including a first electronically controlled pressure generating unit distinct from the master cylinder and operable to generate a braking force at the wheel cylinder in a first mode of operation, a secondary braking unit including a second electronically controlled pressure generating unit distinct from the master cylinder and operable to generate a braking force at the wheel cylinder in a second mode of operation and a pedal feel simulator operable to provide feedback to the brake pedal according to a fixed characteristic of the pedal feel simulator defining a predetermined force-stroke relationship relating a travel distance of the brake pedal to the user input force. In the first mode of operation, the secondary braking unit is operable to receive fluid from the master cylinder to diverge from the predetermined force-stroke relationship at the brake pedal.

An electronically slip-controllable vehicle brake system includes a human-powered master brake cylinder, a pressure generator, an electronically actuatable valve device, a wheel brake, and an electronically actuatable actuator. The wheel brake is connected to the master cylinder and the pressure generator. The pressure generator is drivable via an external force and is configured to supply pressurized brake fluid to the wheel brake. The valve device is configured to control pressure medium connections from the master brake cylinder to the wheel brake and to a suction side of the pressure generator, and includes three pressure medium connections. The actuator is configured to switch the valve device between three different positions whereat the pressure medium connections are connected to or block from each other in different combinations.